Santa Monica City Council
November 18, 2025

Lower Colorado Basin Regional Office
500 Fir Street, Boulder City, NV 89005-2403
702-293-8411
http://www.usbr.gov/
U.S. Army Corps of Engineers
The Corps of Engineers administers a permit program to ensure that the nation’s waterways are used in the public interest. Any person, firm, or agency planning to work in waters of the United States must first obtain a permit from the Army Corps of Engineers. The Corps is responsible for the protection and development of the nation’s water resources, including navigation, flood control, energy production through hydropower management, water supply storage and recreation.

Los Angeles District
915 Wilshire Boulevard, Suite 1101, Los Angeles, CA 90017 213-452-3333
www.spl.usace.army.mil/
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American Public Works Association
1200 Main Street, Suite 1400, Kansas City, MO 64105-2100 816-472-6100
www.apwa.org
Publications
Refer to the papers and publications identified in the footnotes for recent sources of additional information.

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SECTION 9: LANDSLIDES
WHY ARE LANDSLIDES A THREAT TO THE CITY OF SANTA MONICA? Landslides are a serious geologic hazard in almost every state in the United States. Nationally, landslides cause 25 to 50 deaths each year0F
1 . The best estimate of direct and indirect costs of
landslide damage in the United States ranges between $1 and $2 billion annually. In California, landslides are a significant hazard, in part because of the region’s seismic activity, and in part because the region is underlain by weak soils and rocks that can fail when exposed along a slope, especially when saturated. Some landslides result in private property damage, whereas other landslides impact transportation corridors, fuel and energy conduits, and communication facilities.

As the numbers above show, landslides can also pose a serious threat to human life.

Physiographic Setting
The city of Santa Monica is located at the northwestern margin of the Los Angeles Basin and at the transition between the Peninsular Ranges and the Transverse Ranges physiographic provinces of southern California (see Figure 9-1). The Los Angeles Basin is part of the Peninsular Ranges, a region characterized by a northwest-trending structural grain aligned with the San Andreas fault and represented by a series of northwest-trending faults, mountain ranges and valleys stretching from the southern base of the Santa Monica and San Gabriel Mountains south to beyond the Mexican border.

Displacements on faults in this region are mainly of the right-lateral strike-slip and oblique-slip type, and where they have been most recently active, they have deformed the landscape and altered drainage patterns. Some of these faults include the Palos Verdes, Newport-Inglewood and ElsinoreWhittier faults, whereas the hills that formed in response to movement on these faults include the Palos Verdes Hills, the string of elevated hills and mesas from Beverly Hills to Newport Mesa along the Newport-Inglewood fault zone, and the Puente Hills along the Whittier fault.

Alternatively, the Santa Monica Mountains, along with the San Gabriel Mountains to the east, are part of the west-trending Transverse Ranges that form the northern boundary of the Los Angeles Basin. Bounded on the south by the fault system that is responsible for their uplift, these mountains form a topographic, geomorphic, geologic, and tectonic barrier in the region. The section of this fault system within the city of Santa Monica is the Santa Monica fault.

Although located near the rugged Santa Monica Mountains, the landscape within most of the city itself is relatively simple (see Figure 9-1). The northern portion of the city is underlain by a broad, gently south-sloping alluvial fan that emanated from the mountains to the north. On its western boundary, low-lying beaches serve as a buffer between the Pacific Ocean and coastal bluffs. As we will discuss further in this chapter, ongoing erosional processes are causing retreat of these bluff faces. Older marine, lake (lacustrine), playa or estuarine deposits, now elevated above the active floodplain, are present in the southern portion of the city.

Urban development of most of the city took place before mass grading practices became the norm, especially the section of Santa Monica between Montana Avenue on the north, Colorado Avenue on the south, the Pacific Ocean on the west and 26th Street on the east, as this section of the city was built in the late 1870s. Here, the original topography was generally preserved. Ground surface modifications are more prevalent in the southeastern, slightly newer portion of the city, generally

1 https://www.usgs.gov/faqs/how-many-deaths-result-landslides-each-year Local Hazard Mitigation Plan Section 9
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the result of both road grading and cut and fill associated with the leveling of building pads prior to construction. Grading was also likely employed to create the level pad that accommodates the Santa Monica airport runway. Ground surface elevations across the city vary from 0 to 10 feet above mean sea level (amsl) along the beach, to approximately 175 feet amsl at the eastern end of the airport and 340 to 370 feet amsl near the northeastern corner of the city, on Brentwood Knoll and near the intersection of 26th Street with La Mesa Drive. The coastal bluffs in the northwestern corner of the city rise approximately 50 to 150 feet above the beach below. Farther north, in the Pacific Palisades area, the bluffs are approximately 200 feet high.

Figure 9-1: Physiographic Map of Santa Monica and Surrounding Areas See full map with accompanying explanation in Appendix H, as Plate H-1.

Geologic Setting
The physical features described in the previous section are a reflection of the geologic and climatic processes that have impacted this region in the last few million years. Geologists rely on the principles of uniformitarianism that state that the “present is the key to the past.” Since the 1970s, however, geologists have also looked to the past to predict future geological trends or events. Thus, the geologic hazards that are likely to impact Santa Monica in the future are in great part defined by the geologic history of the area, and the age and characteristics of the sediments that occur at or near the ground surface. A geologic map and descriptions of the geologic units that occur at or near the ground surface in Santa Monica are included below on Figure 9-2.

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Figure 9-2: Geologic Map of Santa Monica and Vicinity with Unit Descriptions (for larger version of these figures refer to Appendix H, Plates H-13a and H-13b) Local Hazard Mitigation Plan Section 9
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This principle is the basis for the fault rupture studies required by the State Geologist across the Santa Monica fault and other faults in the region. Essentially, a fault that has moved at least once in the past 11,700 years is thought to have a relatively high probability of moving again in the future, and in response to this, the State mandates that new habitable structures not be placed across the trace of a Holocene-active fault. Similarly, areas that have experienced slope failures in the past are likely to experience slope failures again in the future, especially if the slopes have not been buttressed or strengthened. This section describes the geologic history of the area and the geologic units that occur at and near the ground surface as a means to identifying and addressing where slope failures could impact Santa Monica residents and visitors. As it is discussed further below, unlike fault rupture, which the State mandates to avoid, slope failures are typically addressed and corrected with appropriate engineering design.

The deposits that form the alluvial fan surface underlying the northern half of the city emanated from the Santa Monica Mountains. These deposits were transported to their current location by ancestral streams and/or gravity (as mudflows or slopewash) over thousands to tens of thousands of years, building an approximately 80- to 100-foot-thick section of sand, gravelly sand and silt at the base of the mountains. We know that the Santa Monica Mountains are the source for these sediments because the gravels, which occur in large amounts in the alluvial fan deposits, typically consist of clasts of bedrock types that crop out in these mountains. The rock type most often seen in the gravelly sections is Santa Monica slate, a dark bluish gray metamorphic rock, but lesser amounts of granitic, volcanic and sedimentary rocks eroded from the Topanga, Tuna Canyon and other formations are also present (Figure 9-2).

Deposition of the alluvial fan sediments occurred sporadically, with long periods of quiescence that allowed for the formation of soils at the surface, before being buried by new pulses of sedimentation.

These now-buried soils are typically clay-rich, forming distinct horizons that can be recognized in subsurface studies, and can be correlated across broad areas. Minor colluvial and sheetflow sediments were and continue to be transported and re-deposited during intense precipitation events.

For the most part, however, erosion and downslope movement of these soils now occurs only in a few areas where the soils are not covered by hardscape, and in areas of topographic relief, if the deposits are exposed in slopes.

Large-scale mudflows such as those that deposited the alluvial fan sediments that underlie the northern half of Santa Monica can no longer impact the city, as the alluvial fan surface is now elevated above the active zone of sedimentation and disconnected from the mountains to the north by the deep ravines of Santa Monica Creek and Rustic Creek canyons. These canyons were incised into the alluvial fan surface and underlying units during the last glacial maximum, which occurred approximately 25,000 to 19,000 years ago. At that time a significant portion of the water on the Earth’s surface was stored as ice, in glaciers, and as a result, sea level was approximately 410 feet (±125 meters) below current sea level (Ishiwa et al., 2019). Rivers draining the Santa Monica Mountains and other highlands surrounding the Los Angeles Basin carved deep channels to achieve equilibrium with this lower sea level. Then, once sea level began to rise, and for the next about 12,000 to 16,000 years, until about 7,000 to 3,000 years ago, many of these canyons were backfilled with sediment eroded off the adjacent highlands as these rivers adjusted to a new base level (Romans et al., 2009). Evidence for some of these now submarine canyons can still be observed in bathymetric maps of Santa Monica Bay, including Redondo Canyon, which connects to the modern shoreline, and Santa Monica Submarine Canyon, which has been buried in the continental shelf but can still be observed in the continental slope (Figure 9-3). Potential future mudflows emanating from the Local Hazard Mitigation Plan Section 9
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Santa Monica Mountains to the north would flow into the canyons of Santa Monica and Rustic creeks, and would not extend southward into the city.

Figure 9-3: Bathymetric Map of Santa Monica Bay Showing Offshore Canyons The offshore Santa Monica Submarine Canyon may be related to the drainage that formed the Ballona Gap. This term is now used for the channelized stream (Ballona Creek) that flows at the base of the Baldwin Hills, on their north side, but the gap covers the entire low-lying area between the Beverly Hills and the Baldwin Hills. Moreover, Ballona Creek is now a distributary of the greater Los Angeles River, but in centuries past, at times it would carry the Los Angeles River floodwaters out to sea. The last time this happened was between 1815 and 1825 (Grant and Sheppard, 1939 quoting Layne, 1935). Due to the high degree of urbanization, drainage within Santa Monica is now mostly managed via storm drains that capture runoff from precipitation events. Outside city limits, storm runoff is locally captured by a few key drainages, including Rustic Creek and Santa Monica Creek canyons on the north side, and the Ballona Creek channel to the south.

At depth below the alluvial fan deposits mentioned in the paragraphs above, is a thick sequence of non-marine and marine sediments. Under the Santa Monica area, these sediments extend to depths of between 5,000 and 12,000 feet, whereas in other areas of the Los Angeles basin, these sediments are locally more than 30,000 feet thick (Wright, 1991). Some of these marine deposits are exposed near the bottom of the coastal bluffs, where they sometimes act as planes of weakness for landslides.

This is discussed further below.

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DEFINITIONS
What is a Landslide?
In broad terms, landslides are downslope movements of landmasses, either as nearly intact bedrock blocks, or as jumbled mixtures of bedrock blocks, fragments, debris, and soil. Landslides are a type of “mass wasting” which denotes any down slope movement of soil and rock under the direct influence of gravity. The term “landslide” encompasses events such as rock falls, topples, slides, spreads, and flows, and in general, landslides can be broken down into two categories: 1) rapidly moving (mud or debris flows, rock falls, and rock topples), and 2) slow moving (earth flows and slumps). Movement of larger landmasses can range from rapid to very slow. Rapidly moving landslides or debris flows pose the greatest risk to human life, and people living in or traveling through areas prone to rapidly moving landslides are at increased risk of serious injury or worse.

Slow moving landslides can cause significant property damage, but are less likely to result in serious human injuries.

Geologists also describe the type of movement of a landslide as either: 1) translational (where movement occurs along a relatively planar dipping surface), 2) rotational (where sliding material moves along a curved surface) or 3) wedge (where movement occurs on a wedge-shaped block formed by intersecting planes of weakness, such as fractures, faults and bedding). The size of a landslide usually depends on the geology and the initial cause of the landslide. Landslides vary greatly in their volume of rock and soil, the length, width, and depth of the area affected, frequency of occurrence, and as mentioned above, speed of movement. Shallow slides (referred to as surficial slope failures) are generally about 15 feet or less in depth and involve the near surface soil, and possibly the underlying weathered bedrock. Deeper slides (referred to as gross slope failures) most often consist of bedrock blocks, either severely broken or relatively intact, depending on the bedrock structure and mode of failure.

What is a Debris Flow?
This type of failure is the most dangerous and destructive of all types of slope failure. A debris flow (also called mudflow, mudslide, and debris avalanche) is a rapidly moving slurry of water, mud, rock, vegetation and debris. Larger debris flows are capable of moving trees, large boulders, and even cars. This type of failure is especially dangerous as it can move at great speeds, is capable of crushing buildings, and can strike with very little warning. The development of debris flows is strongly tied to exceptional storm periods of prolonged rainfall, such as storms related to atmospheric rivers. Failure generally occurs during an intense rainfall event, following saturation of the soil by previous rains.

A debris flow most commonly originates as a soil slip in the rounded, soil-filled “hollow” at the head of a drainage swale or ravine. The rigid soil mass is deformed into a viscous fluid that moves down the drainage, incorporating into the flow additional soil and vegetation scoured from the channel.

Debris flows also occur on canyon walls, often in soil-filled swales that do not have topographic expression. The velocity of the flow depends on the viscosity, slope gradient, height of the slope, roughness and gradient of the channel, and the baffling effects of vegetation. Even relatively small amounts of debris can cause damage from inundation and/or impact (Ellen and Fleming, 1987; Reneau and Dietrich, 1987). Recognition of this hazard led FEMA to modify its National Flood Insurance Program to include inundation by “mudslides.” Local Hazard Mitigation Plan Section 9
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CONDITIONS CONDUCIVE TO SLOPE FAILURES
Landslides in the southern California region can be initiated by rainfall, earthquakes, changes in the depth to ground water or overall moisture content of the geologic materials, disturbance and change of a slope by human-made construction activities, changes in vegetation, or any combination of these causes. The potential for slope failure is also dependent on slope height, slope steepness, and shear strength and orientation of the underlying geologic unit(s). For example, water can increase the plasticity of weak clays lining joints or shears, forming planes of weakness along which a landmass can fail.

Failure of a slope occurs when the force that is pulling the slope downward (gravity) exceeds the strength of the earth materials that compose the slope. They can move slowly (millimeters per year), or can move quickly and disastrously, as is the case with debris flows. Debris flows can travel down a hillside at speeds up to 200 miles per hour (but more commonly, 30 – 50 miles per hour), depending on the slope angle, water content, and type of earth and debris in the flow. These flows are initiated by heavy, usually sustained, periods of rainfall, but sometimes can happen as a result of short bursts of concentrated rainfall in susceptible areas. Burned areas charred by wildfires are particularly susceptible to debris flows, as described further below.

For engineering of earth materials, these factors are combined in calculations to determine if a slope meets a minimum safety standard. The generally accepted standard is a factor of safety of 1.5 or greater (where 1.0 is equilibrium, and less than 1.0 is failure). Natural slopes, graded slopes, or graded/natural slope combinations must meet these minimum engineering standards where they impact planned homes, subdivisions, or other types of developments. Slopes adjacent to areas where the risk of economic losses from landsliding is small, such as parks and mountain roadways, are often allowed a lesser factor of safety. From an engineering perspective, landslides are generally unstable (may be subject to reactivation), and may be compressible, especially around the margins, which are typically highly disturbed and broken. The headscarp area above the landslide mass is also unstable, since it is typically oversteepened, cracked, and subject to additional failures.

Thus, locations at risk from landslides or debris flows include the following:
 On or close to steep hills
 Steep road-cuts or excavations
 Existing landslides or places of known historic landslides (such sites often have tilted power lines, trees tilted in various directions, cracks in the ground, and irregular-surfaced ground)  Steep areas where surface runoff is channeled, such as below culverts, V-shaped valleys, canyon bottoms, and steep stream channels
 Fan-shaped areas of sediment and boulder accumulation at the outlets of canyons  Canyon areas below hillside and mountains that have recently (within 1-6 years) been subjected to a wildland fire.

Some of the most common conditions leading to slope failures are described in more detail below.

Natural Conditions
Natural processes can cause landslides or re-activate historical and pre-historical landslide sites. The removal or undercutting of shoreline-supporting material along bodies of water by currents and waves produces countless small slides each year. Seismic tremors can trigger landslides on slopes Local Hazard Mitigation Plan Section 9
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historically known to have landslide movement. Earthquakes can also cause additional failure (lateral spreading) that can occur on gentle slopes above steep streams and riverbanks.

Weathering of geologic materials produces conditions conducive to landslides, while human activity often further exacerbates many landslide problems. Many landslides are difficult to mitigate, particularly in areas of large historic movement with weak underlying geologic materials.

Rock falls occur when blocks of material come loose on steep slopes. Weathering, erosion, or excavations, such as those along highways, can cause falls where the road has been cut through bedrock. Rock falls are fast moving, with the materials free falling or bouncing down the slope. In falls, material is detached from a steep slope or cliff. The volume of material involved is generally small, but large boulders or blocks of rock can cause significant damage.

As the list of historical landslides suggests, landslides are often triggered by periods of heavy rainfall.

Certain geologic formations are more susceptible to landslides than others. Human activities, including locating developments near steep slopes, can increase susceptibility to landslide events.

Landslides on steep slopes are more dangerous because movements can be rapid.

Wildland fires in hills covered with chaparral are often a precursor to debris flows in burned out canyons. The extreme heat of a wildfire can create a soil condition in which the earth becomes impervious to water by creating a waxy-like layer just below the ground surface. Since the water cannot be absorbed into the soil, it rapidly accumulates on slopes, often gathering loose particles of soil that combine to form a sheet of mud and debris. Debris flows can often originate upstream, miles away from a developed area, and approach the built environment at the mouth of a canyon at a high rate of speed and with little warning.

Impacts of Development and Redevelopment
Although landslides are a natural occurrence, human impacts can substantially affect the potential for landslide failures to occur. Grading and construction can decrease the stability of a hill slope by adding weight to the top of the slope, removing support at the base of the slope, and increasing water content. Grading for road construction and development can increase slope steepness. Other human activities effecting landslides include excavation, drainage and groundwater alterations, and changes in vegetation (as discussed further below). Proper planning and geotechnical engineering if applied judiciously, however, can be implemented to reduce the threat to people, property, and infrastructure posed by unstable slopes.

Slope excavation is common in the development of home sites or roads on sloping terrain. Grading these slopes sometimes results in slopes steeper than the pre-existing natural slopes. Since slope steepness is a major factor in landslides, these steeper slopes can be at an increased risk for landslides. The added weight of fill placed on slopes can also result in an increased landslide hazard.

Small landslides can be fairly common along roads, both along the road-cut and the road-fill sections. Landslides occurring below new construction sites are indicators of the potential impacts stemming from excavation. Alternatively, if unstable slope conditions are recognized and engineered for during grading, originally unstable or marginally stable slopes can be made safer.

Alterations to Drainage and Groundwater Systems
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the amount of water flowing into landslide-prone slopes can increase landslide hazards. Broken or leaking water or sewer lines and seepage fields can be especially problematic, as can water retention facilities that direct water onto slopes. However, even lawn irrigation in landslide–prone locations can result in damaging landslides. Ineffective storm water management and excess runoff can also cause erosion and increase the risk of landslide hazards. Drainage can be affected naturally by the geology and topography of an area. Development that results in an increase in impervious surfaces (such as concrete- or asphalt-paved roads) impairs the ability of the land to absorb water and may redirect water to other areas. Channels, streams, ponding, and erosion on slopes all indicate potential slope problems.

Road and driveway drains, gutters, downspouts, and other constructed drainage facilities can concentrate and accelerate runoff flow. Ground saturation and concentrated velocity flow are major causes of slope problems and may trigger landslides.

Changes in Vegetation
Removing vegetation from very steep slopes can increase landslide hazards. Areas that experience wildfire and land clearing for development may have long periods of increased landslide hazard.

Also, certain types of non-native ground covers require extensive irrigation to remain green. As a result, clearing and replacement of native ground covers with non-native covers can lead to an increase in slope failures.

Watersheds that have been recently burned typically yield greater amounts of soil and debris than those that have not burned. Erosion rates during the first year after a fire are estimated to be 15 to 35 times greater than normal, and peak discharge rates range from 2 to 35 times higher. These rates drop abruptly in the second year, and return to normal after about 5 years (Tan, 1998).

In addition, debris flows in burned areas are unusual in that they can occur in response to small storms and do not require a long period of antecedent rainfall. These kinds of flows are common in small gullies and ravines during the first rains after a burn, and can become catastrophic when a severe burn is followed by an intense storm season (Wells, 1987). The United States Geological Survey (USGS), as part of its National Landslide Hazards Program1F 2 , has developed tools and
methodologies to identify and quantify slope stability hazards posed by burned watersheds. These tools include the installation of instruments in recently burned watersheds and canyons to collect data on rainfall, flow stage, soil moisture, and other parameters, and the development of mathematical models that use these data to predict the onset of landslides in an effort to develop real-time warning systems2F
3 .

HISTORICALLY AND LOCALLY SIGNIFICANT SOUTHERN CALIFORNIA

LANDSLIDES
Historically, there have been many landslides in the southern California area. Landslides recorded in the latter half of the 20th century alone caused losses of more than $5 billion (in 2000 dollars, approximately equivalent to $9 billion in 2023 dollars). Many of these landslides occurred after

2 https://www.usgs.gov/programs/landslide-hazards/what-we-do-landslide-hazards-program, accessed Dec. 2023 3 https://www.usgs.gov/programs/landslide-hazards/science/real-time-monitoring-potential-landslides, accessed Dec. 2023.

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particularly wet winters; others occurred in response to strong ground shaking during an earthquake.

Some of the costlier or most damaging landslides reported in the region and in the Santa Monica area are summarized below.
1956 Portuguese Bend Landslide, Palos Verdes
Cost: $14.6 million (2000 dollars; ~$26 million in 2023 dollars), on California Highway 14 in the Palos Verdes Hills. The Portuguese Bend landslide is a reactivated ancient slide that began its modern movement in August 1956, when displacement was noticed at its northeast margin.

Reactivation is blamed in part to human activity, including the extensive use of septic tanks and seepage pits for residential structures. Movement gradually extended downslope so that the entire eastern edge of the slide mass was moving within six weeks. By the summer of 1957, the entire mass was sliding towards the sea.
1969 Glendora, Los Angeles County
Cost: $26.9 million (2000 dollars; ~$50.3 million in 2024 dollars). The winter of 1969 was one of the wettest on record in the southern California area. The rain caused many of the streams draining the San Gabriel Mountains to overflow, resulting in debris flows that damaged 175 houses in the Glendora area alone.
1977-1978 Monterey Park, Baldwin Hills and Repetto Hills, Los Angeles County
Cost, >$14.6 million (2000 dollars; >~$27 million in 2024 dollars); 100 houses damaged due to debris flows; at least 3 people died; more than 300 evacuated from their apartment building and many more displaced from their homes in Culver City3F
4 .
1978 Bluebird Canyon, Orange County
Cost: $52.7 million (2000 dollars; ~$98.3 million in 2024 dollars); 60 houses destroyed or damaged.

On October 2, 1978, a portion of the Bluebird Canyon slope gave way, in great part due to the unusually heavy rains in March that may have contributed to initiation of the landslide. Although the 1978 slide area was approximately 3.5 acres, it is suspected to be a portion of a larger, ancient landslide.
1979 Big Rock, Los Angeles County
Cost: approximately $1.08 billion (2000 dollars; ~$2.02 billion in 2024 dollars); rockslide that caused damage to California Highway 1 (Pacific Coast Highway) in the Malibu area. High groundwater levels attributed to the use of septic tanks is considered a leading cause of this landslide. 1980 Southern California Landslides
Cost: $1.1 billion in damage (2000 dollars; ~$2.06 billion in 2024 dollars). Heavy winter rainfall in 1979-80 caused damage in six southern California counties. A sequence of five days of continuous rain that started on February 8 dropped more than 7 inches of water by February 14. Slope failures began to develop by February 15 and then very high-intensity rainfall occurred on February 16. As

4 https://www.nytimes.com/1978/03/05/archives/mudslides-kill-three-on-coast-as-hundreds-flee-homesdomestic.html, accessed Dec. 2023.

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much as 8 inches of rain fell in a 6-hour period in many locations. 1978-1979, 1980 San Diego County
San Diego County experienced major damage from storms in 1978, 1979, and 1979-80, as did neighboring areas of Los Angeles and Orange Counties. One hundred and twenty landslides were reported to have occurred in San Diego County during these two years. Rainfall for the rainy seasons of 1978-79 and 1979-80 was 14.82 and 15.61 inches respectively, compared to a 125-year average (1850-1975) of 9.71 inches. Significant landslides occurred in the Friars Formation, a geologic unit known to be slide-prone. [Of the nine landslides that caused damage in excess of $1 million (2000 dollars; ~$1.87 million in 2024 dollars) in the northern part of San Diego County, seven occurred in the Friars Formation, and two in the Santiago Formation.] 1983 San Clemente, Orange County
Cost: $65 million (2000 dollars; ~$121.5 million in 2024 dollars), California Highway 1. Litigation associated with this landslide ultimately cost approximately $43.7 million (2000 dollars; $81.7 million in 2024).
1983 Big Rock Mesa, Malibu, Los Angeles County
Cost: $706 million (2000 dollars; ~$1.32 billion in 2024 dollars) in legal claims; 13 houses condemned and 300 more threatened due to rockslide triggered by intense rainfall. 1994 Northridge Earthquake Landslides
As a result of the magnitude 6.7 Northridge earthquake, more than 11,000 landslides occurred over an area of 10,000 km2
. Most landslides occurred in the Santa Susana Mountains and in mountains north of the Santa Clara River Valley. The landslides destroyed dozens of homes, blocked roads, and damaged oil-field infrastructure. Several landslides were reported in the bluffs along PCH in Santa Monica, Pacific Palisades and Malibu4F
5 .
1995 Los Angeles and Ventura Counties Landslides
Cost – undetermined yet, but most likely in the billions, including litigation. Above-normal rainfall in March triggered damaging debris flows, deep-seated landslides, and flooding. Several deep-seated landslides were triggered by the storms, the most notable being the La Conchita landslide, which in combination with a local debris flow, destroyed or badly damaged 14 homes in the small town of La Conchita, about 20 km west of Ventura. There also was widespread debris-flow and flood damage to homes, commercial buildings, and roads and highways in areas along the Malibu coast that had been devastated by wildfire two years before.
2003-Present Del Mar Bluff Stabilization, San Diego County The Los Angeles-San Diego-San Luis Obispo (LOSSAN) rail corridor is the only rail connection between San Diego and the rest of the state and nation. The economy depends on this connection for both passenger and freight transport, but landslides, rapid erosion, and seismic activity have caused collapses along the Del Mar Bluffs. San Diego Association of Governments is working with the North County Transit District (NCTD) to stabilize the Del Mar Bluffs to maintain the integrity of

5 https://usgs.maps.arcgis.com/apps/webappviewer/index.html?id=ae120962f459434b8c904b456c82669d; accessed December 5, 2023.

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both the rail line and the surrounding area. Since 2003, the first four phases of the stabilization project have been completed and have identified the funding needed to complete the final two phases. In Phase 5, existing structures will be repaired and additional supports to stabilize the bluffs will be installed. Phase 5 began in 2024, is anticipated to last through 2026, and will cost approximately $88 million, funded through a combination of state, federal, and local sources. 2005 La Conchita Landslide, Ventura County
Cost – undetermined yet, but most likely in the billions, including litigation. On January 10, 2005 a landslide struck the sea-side community of La Conchita destroying 13 homes, severely damaging 23 others, and killing 10 people. The landslide occurred in an area known for prior landslide activity (more recently in 1995), and was the direct result of intense rainfall in the area, compounded by weak sediments and steep slopes. The landslide material failed almost simultaneously, and descended down the slope as a highly fluid, rapidly moving debris flow, with top speeds estimated at 30 feet per second (Jibson, 2005, 2006).
2005 Blue Bird Canyon Landslide, Laguna Beach, Orange County Cost – undetermined yet, but probably in the billions, in great part due to litigation. On June 1, a landslide began moving in the area, almost certainly in response to the extremely wet winter rains earlier that year, in January and February. This landslide occurred in the same general area as the 1978 landslides. Seventeen houses were destroyed, 11 were damaged, and another 23 were threatened. Fortunately, no one died or was seriously hurt. 2018 Montecito Landslide, Santa Barbara County
Cost – undetermined yet, but most likely in the billions. Early on the morning of January 9, 2018, mudflows struck Montecito, which had been affected by the 2017 Thomas Fire, and other areas of Santa Barbara County. An estimated 0.5 inches of rain fell within a five-minute period at approximately 3:30 a.m. causing mud and boulders from the Santa Ynez Mountains to flow down creeks and valleys into Montecito. The debris flows that impacted the lower areas of Montecito. were up to 15 feet high, included mud, boulders and tree branches, and moved at estimated speeds of up to 20 miles per hour. The mudflows resulted in 23 confirmed deaths, and more than 150 people were hospitalized with various injuries, including four in critical condition. The mudflows destroyed over 100 homes, damaged an additional 300, and blocked Highway 101 for months. 2021-2023 San Clemente Landslides, Orange County
On September 15, 2021, waves crashing over the rails damaged the train tracks in San Clemente.

The rail segment had to be shut down through October 3, 2021. Then, on September 29, 2022 the segment was again closed to passenger traffic due to soil movement; freight traffic continued at lowered speeds. Rocks were added after each incident to protect the slope from wave action and the passenger rail traffic stop continued as anchors were being placed into bedrock. The line fully reopened in April 2023, but rail service was soon halted again, this time two miles to the north.

Falling debris did not damage the tracks but ground movement continued from a landslide involving Casa Romantica on the bluff above. During the work closures, freight trains were able to resume at a speed of 10 miles per hour with officials onsite determining when it was safe to proceed. Full service resumed in late May 2023 but was halted indefinitely again in early June 2023. Orange County Transportation Authority (OCTA), which owns the section of track, declared an emergency on June 12, 2023 to speed up construction of a temporary barrier wall at the bottom of the slope.

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Service resumed on July 19, 2023.
2023 Rolling Hills Estates Landslide, Los Angeles County Cost – undetermined yet, but expected to be in the millions of dollars. Homes in a canyon were destroyed when the ground shifted on the northern side of Los Angeles County's Palos Verdes Peninsula. A landslide forced the evacuation of at least 12 homes in Rolling Hills Estates, where houses and garages cracked and crumbled in a canyon area. Deputies were sent to patrol the evacuated neighborhood, where about 16 people were displaced. 2023 Santa Monica Bluff Stabilization Emergency Work, Los Angeles County In July 2023, the City of Santa Monica mitigated an unstable portion of the Santa Monica Bluffs located just above the Pacific Coast Highway (PCH), between the California Incline and the northbound on-ramp to Moomat Ahiko Way. A portion of the bluff had a large crack that likely formed in response to the intense rains that occurred in the region in December 2022-January 2023.

The block of sediment that had separated from the main escarpment was proactively removed to ensure traffic safety and uninterrupted vehicle movement on PCH. The bluff removal was completed on July 26, 2023.

LANDSLIDE HAZARD ASSESSMENT FOR SANTA MONICA
Hazard Identification
Identifying hazardous locations is an essential step towards implementing more informed mitigation activities. Landslide deposits of Holocene and possibly latest Pleistocene age covering areas greater than about 12 acres (50,000 square meters) have been mapped north of the city of Santa Monica, on the landward side of PCH, within and north of the area covered by Figure 9-2 (the landslides mapped within the area covered by the map are shown in bright yellow). These large landslides in the Pacific Palisades and Malibu areas generally occur where siltstone and claystone beds in the marine units at the base of the cliffs dip out of slope. These failures are often translational slides that involve larger masses of material.

Smaller landslides and mudflows too small for the scale of Figure 9-2 have been reported along the coastal bluffs in Santa Monica proper as a result of both the 1994 Northridge earthquake and various intense rainfall events5F
6 , including the 1998 El Niño storms. Although not reported in the literature, slope failures are also likely to have occurred adjacent to the canyons that border the city on its northern side. These areas have steep slopes with gradients exceeding 40 degrees, and locally even nearly vertical (see red areas shown on Figure 9-4). These slopes are susceptible to both erosion and slope failure.

6 https://usgs.maps.arcgis.com/apps/webappviewer/index.html?id=ae120962f459434b8c904b456c82669d; accessed on December 5, 2023.

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Figure 9-4: Slope Distribution Map for Santa Monica and Adjoining Areas The smaller landslides that have occurred on the 50- to 150-foot-high, west- to southwest-facing coastal bluffs are typically generated from the horizontally bedded, Pleistocene, uncemented to slightly cemented sandy to gravelly alluvial fan materials that comprise most of the cliff face. Slope damage in these materials is often the result of increased pore water pressures following periods of heavy precipitation or over-irrigation. Blocks of these deposits locally separate from the larger mass and fail as block slides, or topples. If saturated as a result of intense winter rains, some sections may also fail as mudslides. Given the height of the bluffs and their exposure to the elements, localized slope failures of these materials can be expected to occur sporadically. As mentioned previously, in the historical landslide discussion, portions of the bluffs have also failed historically in response to strong ground shaking (see the entry for the 1994 Northridge earthquake). Areas susceptible to significant, potentially costly or damaging slope failures are shown in red on Figure 9-5.

The underlying marine deposits consist of bluish gray clay and fine sand. Coastal storms characterized by strong winds, high waves, and significant runoff can be locally damaging to the base of the bluffs, although in the Santa Monica area, PCH and the structures west of the road generally serve as a buffer between the waves and the bluffs. Landslide deposits, regardless of Local Hazard Mitigation Plan Section 9
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whether related to surficial or deep-seated failures, tend to be friable, susceptible to settlement and additional slippage, and thus do not make acceptable foundation materials.

Small surficial slope failures may also occur in other parts of the city with topographic relief. As discussed above, slope steepness has a strong influence on the development of flows, with most failures occurring on slopes with gradients of between about 20 and 56 degrees, and a large percentage of debris flows occurring on slopes between 20 and 36 degrees (Campbell, 1985; Morton et al., 2003). Slopes with gradients between 26 and 40 degrees are shown in yellow on Figure 9-4, and slopes with gradients between 10 and 26 degrees are shown in green. Based on this slope distribution map, there are several areas in Santa Monica where surficial slope failures in the form of flows, slips and soil creep could occur. These areas include slopes flanking the I-10 freeway, slopes flanking the southern and southwestern portions of the Santa Monica Airport, several slopes in the south side of the city between Ashland Avenue and Dewey Street, and slopes on the flanks of Brentwood Knoll. The slopes that may be susceptible to surficial failures are identified in light green on Figure 9-5.

Although several of these slopes are either hardscaped or landscaped, some sections expose soils at the surface, and if these deposits become very wet, they could experience slope creep or soil slips.

Surficial slope failures may also develop when concentrated runoff erodes the surficial deposits and creates rills on the slope faces that, if left unchecked, can eventually become soil flows, earth flows or debris flows. These areas, and small backyard slopes not shown on Figure 9-5, if not properly maintained, and especially if impacted by burrowing animals such as ground squirrels and voles, could experience small-scale failures following strong winter storms. This hazard can be mitigated, or at least managed, if the slopes are well maintained and surface runoff is diverted and not allowed to pool at the top of slopes.

Areas within and near the city of Santa Monica that could experience mudslides and debris flows include the canyons along and immediately north of the city, including Santa Monica Creek and Rustic Creek canyons. These areas may be particularly susceptible to this hazard if the areas upslope burn as a result of a wildland fire.

Santa Monica is for the most part built out, and new developments typically occur in previously built lots where the older structures are demolished and replaced with new buildings. These infill projects require that the soils be tested for their geotechnical properties, with geotechnical reports describing the analyses submitted to the City for approval before construction can begin. This, in addition to standard-of-practice construction practices, limits the likelihood of landslides occurring as a result of modifications to the terrain during construction.

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Figure 9-5: Areas in Santa Monica Susceptible to Slope Failure Vulnerability and Risk
A vulnerability assessment for landslides can help predict how different types of property or infrastructure and population groups will be affected by the hazard of unstable slopes. As mentioned in previous sections, some of the most important factors defining the hazard of slope instability include slope height, slope steepness, sheer strength, and orientation of weak layers in the underlying geologic units, as well as pore water pressures. The slope map for Santa Monica presented on Figure 9-4 is based on data obtained in 2002-2003, and is thus representative of areas in the city previously modified by grading. The slopes identified, together with historical data on previous slope failures, was used to develop Figure 9-5, which shows those areas in the city most likely to be impacted by slope failures. These data in turn can be used to assess the population and approximate total value of the properties and infrastructure at risk from future landslide occurrences.

As mentioned above, landslides have occurred and are likely to continue to occur along the bluff areas on the west side of Palisades Park, and further north, along Pacific Coast Highway in the Pacific Local Hazard Mitigation Plan Section 9
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Palisades and Malibu areas. In Santa Monica, the bluffs and the land immediately adjacent to the bluffs are part of Pacific Palisades Park and thus managed by the City. There is only one structure near the bluffs that could be impacted by slope failure. This structure is the City of Santa Monica Camera Obscura Art Lab, a facility that houses Santa Monica’s historical Camera Obscura artifact and serves as a community arts education center. The structure is located in Palisades Park near the intersection of Broadway and Ocean Avenue. Otherwise, at the bottom of the bluffs, the existing private properties are separated from the slope face by PCH, so damage to these structures is expected to be minor, if any.

Failures of the bluffs pose a hazard primarily to PCH and, if they occur suddenly, to motorists using PCH and the incline descending into and ascending from PCH. The probability of slope failure onto PCH is low, but the risk to limb and life is moderate to high given that this is a major route with significant traffic. Even if no one is physically harmed by a slope failure, sections of PCH would have to be closed to through-going traffic while cleanup of debris is ongoing. The resulting delays, detours, or right-out closures would pose significant socio-economic impacts to Santa Monica residents, and the residents of other communities served by this section of PCH. Significantly, however, a partnership between the California Department of Transportation and the City of Santa Monica facilitated the California Incline Bridge Replacement Project. This $17 million project was completed in September 2016 and included the construction of a new seismically upgraded vehicular bridge that includes a shared pedestrian/bicycle path. The construction project included the installation of 1,000 soil nails6F
7 to stabilize that section of the bluffs.

Moreover, given the potential impacts to the community and most importantly, the transportation network, the City monitors these slopes on an on-going basis, and over the years has implemented a variety of mitigation measures, such as the one discussed above, aimed at reducing the hazard of slope failure along the coastal bluffs in Pacific Palisades Park. These measures include capturing and re-directing surface runoff away from the bluff face to prevent erosion of the bluffs and limit infiltration of water into the underlying units. The area next to the bluffs with these special runoff considerations is shown on Figure 9-5. To supplement this effort, in 2010 the City retained a contractor who drilled horizontal subdrains (called hydraugers) into the bluff face; the drains capture groundwater that may collect at the boundary between highly permeable and less permeable geologic units, with the overall goal of reducing pore water pressures in the sediments that form the bluffs. In 2012, sections of the park were also re-graded to prevent surface water from flowing over the edge of the cliff and down the bluff face. If unstable slope sections are identified, the City conducts emergency work to remove the unstable section and stabilize the surrounding slopes. This was done most recently in July 2023, when a section of the bluff between the California Incline and Moomat Ahiko Way on-ramp to PCH was found to have destabilized, most likely in response to the 2022-2023 wet winter. As of late 2023, the City had just retained a geotechnical consultant to provide maintenance recommendations for the hydraugers that were installed in 2010.

The limited historical landslide damage elsewhere in Santa Monica is likely attributable to land development fundamentals that have been practice in southern California since the 1950s, including stricter hillside grading ordinances, sound project design that avoids severely hazardous areas, soil engineering practices that include detailed preliminary investigations and oversight during grading,

7 Soil nailing is a well-established remedial construction measure that uses relatively slender reinforcing elements (such as rebar) inserted into holes drilled into to slope and then grouted into place. Sometimes concrete or shotcrete is applied on the slope face. Alternatively, a mesh may be placed against the slope face, secured to the soil beneath the nail head plates.

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and effective agency review of hillside grading projects. Geotechnical review of all proposed new development and re-development projects should be continued.

Nevertheless, and although potential future slope failures in Santa Monica are anticipated to impact relatively small areas, the dollar loss could be high (in the tens of thousands to hundreds of thousands of dollars) if structures are damaged. Since insurance policies typically do not cover landslide damage and homeowners in the areas likely to be impacted by these localized soil slips are likely to not have flood insurance, slope failures can cause both an economic and emotional burden to property owners in the failure area. Moreover, even if a slope failure does not impact adjacent properties, the visual impact of a ruined slope can cause alarm among adjacent homeowners and can impact property values.

For these reasons, mitigation measures designed to prevent or reduce the impact of potential slope failures should be considered on an on-going basis. There are numerous methods for mitigating slope instability; selecting the most appropriate method for a given area should take into account the local geological conditions, safety needs, type and cost of construction repair, and aesthetics.

Any and all measures implemented to reduce the potential for erosion and slope failure need to be monitored regularly to ensure that they are performing as intended.

SUMMARY OF COMMUNITY LANDSLIDE ISSUES
What is Susceptible to Landslides?
The city’s hillsides are vulnerable to the types of slope instability mentioned above. Specifically, the steep-sided coastal bluffs and slopes along deeply incised drainages may be locally susceptible to slope instability in the form of block slides, topples and mudslides. This assessment is backed by historical data that show that if a landslide occurs along the coastal bluffs, communities served by PCH, including Santa Monica, would suffer immediate damages and loss of service. Specifically, the California Incline road leading to PCH is flanked by terrain that in the past has experienced landslide activity, and where the slope instability susceptibility is mapped as high. During an earthquake, or as a result of intense and/or protracted rainfall, the road could be impacted by slope failures. Less steep and lower slopes elsewhere in the city could locally experience surficial slope failures following intense or protracted rainfall events, especially if surface runoff is not managed correctly. The slope failures more likely to occur in these areas are of the soil slip, earth flow or debris flow variety.

Factors included in assessing landslide risk include population and property distribution in the hazard area, the frequency of landslide or debris flow occurrences, slope steepness, soil characteristics, and precipitation intensity. This type of analysis could generate estimates of the damages to the city due to a specific landslide or debris flow event, however, predicting the location, timing and size of a landslide is still not possible with the scientific methods currently available7F 8 .

Furthermore, there is little to no data regarding the economic costs of landslides in the United States that can be used to make valid predictions as to what a landslide event could cost in the future. The available data do suggest that the indirect costs associated with landslides, which include the closure of impacted transportation routes, are thought to exceed the direct costs by a factor of two or more8F 9 .

8 https://pubs.usgs.gov/of/2022/1075/ofr20221075.pdf, pg. 5, accessed on Dec. 10, 2023. 9 https://pubs.usgs.gov/of/2022/1075/ofr20221075.pdf, pg. 11, accessed on Dec. 10-14, 2023.

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A generalized review of the potentially unstable slope areas in the city, as shown on Figures 9-4 and 9-5, and comparison with the location of the City’s critical/essential facilities (Plate H-4) shows that most of the essential facilities in the city are not located in an area susceptible to slope instability.

The only exceptions are Fire Station 7, located at 1100 Pacific Coast Highway, and Mt. Olivette and Riviera reservoirs. These facilities may not be damaged by the potential slope failures, but access to or from these facilities may be obstructed. This in turn would impact emergency services from Fire Station 7, and water distribution services from the reservoirs. The economic and societal cost of these scenarios has the potential to be substantial, but currently unquantifiable. However, the City of Santa Monica has redundancies, with several additional fire stations and water storage reservoirs available to draw from in the short term.

Closures (which would require detours around the region) or limited access (with consequential delays) on PCH, have the potential to cause major disruption to emergency services, especially the mobilization of people in need of emergency services to the local hospitals. Therefore, inspection and repair of critical transportation facilities and routes is essential and should receive high priority.

Both PCH and the I-10 freeway are also designated as potential evacuation routes (Plate H-5), so slope failures along these roadways could have an impact on evacuations if the slope failures were the result of, or coincided with another natural disaster that prompted the evacuation of some portions of the city. An example of this kind of cascade scenario would be an earthquake on the offshore section of the Palos Verdes fault that causes a tsunami and slope damage along PCH, resulting in PCH being too damaged to serve as an evacuation route for people attempting to reach higher ground in advance of the tsunami. This low-probability but high-risk scenario has the potential to result in hundreds to thousands of injuries and deaths.

Future landslides along the coastal bluffs and other slopes in the city could affect not only the transportation system, but utility services and critical lifelines. Utilities, including potable water, wastewater, telecommunications, natural gas, and electric power are all essential to service community needs. Loss of electricity has the most widespread impact on other utilities and on the whole community. Natural gas pipes may also be at risk of breakage from landslide movements as small as an inch or two. Ideally, lifelines and utility services should remain operational during and following a natural hazard event. For this reason, slope areas showing signs of erosion should be mitigated before the next significant storm, to reduce the potential for damage to not only private property, but infrastructure and lifelines.

Landslide Mitigation Activities
Landslide mitigation activities include current mitigation programs and activities that have been implemented by the City, in addition to developers, residents, and State agencies (such as Caltrans).

All proposed development and redevelopment projects require a site-specific geotechnical evaluation of any slopes that may impact the future use of the property. This includes existing slopes that are to remain, and any proposed graded slopes. The investigation typically includes borings to collect geologic data and soil samples, laboratory testing to determine soil strength parameters, and engineering calculations. Numerous soil-engineering methods are available for stabilizing slopes that pose a threat to development. These methods include designed buttresses (replacing the weak portion of the slope with engineered fill); reducing the height of the slope; designing the slope at a flatter gradient; and adding reinforcements such as soil cement or layers of geogrid (a tough polymeric net-like material that is placed between the horizontal layers of fill). Most slope stabilization methods include a subdrain system to remove excessive ground water from the slope area, such as the system implemented by the City along the Pacific Palisades Park. If it is not feasible Local Hazard Mitigation Plan Section 9
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to mitigate the slope stability hazard, building setbacks are typically imposed.

There are numerous methods for mitigating block slides and topples. Choosing the best method depends on the geological conditions (i.e., slope height, steepness, fracture spacing, bedding orientation), safety, type and cost of construction repair, and aesthetics. A commonly used method is to regrade the slope, a mitigation measure that Santa Monica has also employed in the past along the coastal bluffs. This ranges from locally trimming hazardous overhangs, to completely reconfiguring the slope to a more stable condition, possibly with the addition of benches to catch small rocks. Another group of methods focuses on holding the fractured rock or sediments in place by draping the slope with wire mesh, or by installing tensioned rock bolts, tie-back walls, or even retaining walls. Shotcrete is often used on slope faces to prevent raveling in highly fractured rock, but its primary purpose is to offer surface protection only. A third type of mitigation includes catchment devices at the toe of the slope, such as ditches, walls, or combinations of both. Designing the width of the catchment structure requires analysis of how the rock or sediments will fall. For instance, the slope gradient and roughness of the slope determines if rocks will fall, bounce, or roll to the bottom. Rock slope stabilization may also include the addition of drains in order to reduce water pressure within the slope (Wyllie and Norrish, 1996).

For debris flows, assessment of this hazard for individual sites should focus on structures located or planned in vulnerable positions. This generally includes canyon areas; at the toes of steep, natural slopes; and at the mouth of small to large drainage channels. Mitigation of soil slips, earthflows, and debris flows is usually directed at containment (debris basins), or diversion (impact walls, deflection walls, diversion channels, and debris fences). A system of baffles may be added upstream to slow the velocity of a potential debris flow. Other methods include removal of the source material, placing subdrains in the source area to prevent pore water pressure buildup, or avoidance by restricting building to areas outside of the potential debris flow path.

There are a number of options for management of potential slope instability in developed hillsides.

1. Complete a detailed survey and assessment of existing developments in areas recognized to be vulnerable to potential slope failures (like the bluffs along Pacific Palisades Park).

2. Protect existing development and population where appropriate by physical controls such as drainage, slope-geometry modification, protective barriers, and retaining structures.

3. Implement monitoring or warning systems. For instance, in some recently burned watersheds, the USGS, in cooperation with the National Weather Service, installs and operates a system for real-time warnings for storm-related slope failures. Using a combination of tracking storm systems, measuring actual rainfall with a network of rain gauges, and comparing thresholds for the initiation of debris flows, they are able to issue Flash Flood/Debris Watches during the most intense storms, as necessary. This would be most appropriate for the canyons along Santa Monica Creek and Rustic Creek if the slopes above burned during a wildland fire.

4. Post warning signs in areas of potential slope instability.

5. Encourage homeowners to use landscaping methods that help stabilize the hillsides.

6. Incorporate recommendations for potential slope instability into geologic and soil engineering reports for additions and new grading.

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7. Educate the public about slope stability, including the importance of maintaining drainage devices. USGS Fact Sheet FS-071-009F
10 (May, 2000) and the CGS Note 3310F11 (November,
2001) provide public information on landslide and mudslide hazards.

LANDSLIDE RESOURCE DIRECTORY
City Resources
City of Santa Monica Community Development Department
1685 Main Street
Santa Monica, California 92660
Ph: 310-458-2275
County Resources
Los Angeles County Department of Regional Planning
320 West Temple Street
Los Angeles, CA 90012
Ph: 213-974-6411
State Resources
California Geological Survey, Southern California Regional Office 320 W. 4th Street, Suite 850
Los Angeles, CA 90013
Ph: 213-239-0877
California Geological Survey, Headquarters
801 K Street, MS 12-30
Sacramento, CA 95814
Ph: 916-445-1923
California Division of Forestry, Headquarters
1416 9th Street
PO Box 944246
Sacramento, CA 94244-2460
Ph: 916-653-5123
California Department of Water Resources
1416 9th Street
Sacramento, CA 95814
Ph: 916-653-6192
Flood Operations Center Ph: 800-952-5530

10 https://pubs.usgs.gov/publication/fs07100 11 https://www.conservation.ca.gov/cgs/Pages/Publications/Note_33.aspx Local Hazard Mitigation Plan Section 9
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Governor’s Office of Emergency Services (Cal OES)
3650 Schriever Avenue
Mather, CA 95655
Ph: 916-845-8510; Fax: 916-845-8511
www.caloes.ca.gov
California Department of Transportation (Cal Trans) – District 7 100 South Main Street
Los Angeles, CA 90012
Ph: 213-897-3656
Federal Resources and Programs
Federal Emergency Management Agency (FEMA) – Region IX
1111 Broadway, Suite 1200
Oakland, CA 94607-4052
Ph: 510-627-7100
Southern California Field Office Ph: 626-851-7900
Natural Resource Conservation Service (NRCS)
National Water and Climate Center
1201 NE Lloyd Boulevard, Suite 802
Portland, OR 97232-1274
Ph: 503-414-3031
US Geological Survey, National Landslide Information Center Mail Stop 966, Box 25046
Denver Federal Center
Denver, CO 80225
Ph: 800-654-4966 or 303-273-8588
National Oceanic and Atmospheric Administration
National Weather Service
San Diego Weather Forecast Office
11440 W. Bernardo Court, Suite 230
San Diego, CA 92127
Ph: 858-675-8700
Publications
(for References, Refer to Appendix I)
Godt, J.W., Wood, N.J., Pennaz, A.B., Dacey, C.M., Mirus, B.B, Schaefer, L.N., and Slaughter, S.L., 2022, National strategy for landslide loss reduction: U.S. Geological Survey Open-File Report 2022–1075, 36 p., https://doi.org/10.3133/ofr20221075 (available at https://pubs.usgs.gov/publication/ofr20221075).

Strategy document that describes goals and actions that can help reduce the United States’ risk Local Hazard Mitigation Plan Section 9
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from landslide hazards un equitable and effective ways. Publication also includes several additional recent references and links to websites on landslide hazards.

Olshansky, Robert B., 1996, Planning for Hillside Development: American Planning Association.

This document describes the history, purpose, and functions of hillside development and regulation and the role of planning, and provides excerpts from hillside plans, ordinances, and guidelines from communities throughout the US.

Olshansky, Robert B. and Rogers, J. David, 1987, Unstable Ground: Landslide Policy in the United States: Ecology Law Quarterly.

This report discusses the history and policy of landslide mitigation in the US.

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SECTION 10: WILDFIRES & URBAN FIRES
WHY ARE FIRES A THREAT TO THE CITY OF SANTA MONICA?
Although, historically, Santa Monica has not experienced a wildfire within its limits, the city is bordered to the north by natural areas that have burned in the past and could burn again in the future. Moreover, recent past wildfires in California, including the devastating January 2025 fires in the Los Angeles region, have shown that wildfires can easily spread into developed areas, especially when wildfires burn at or near the wildland-urban interface0F 1 (WUI), with ignited structures then
sustaining and transmitting the fire from one building to the next.

As will be discussed further in this section, one of the reasons wildfires have become more destructive and deadly in recent years is the expansion of the WUI, which exposes an increasingly larger number of people and property to this hazard. Moreover, the scale, frequency, and intensity of wildfires in California has increased in the last two decades and is expected to continue to increase due to climate change, with wildland fires in turn impacting and driving climate change.

Notably, the smoke from wildfires increases air pollution levels, emitting massive quantities of carbon dioxide and other substances into the atmosphere that add to the region’s greenhouse gas emissions (see Section 11), and can create a significant health risk in the impacted area and areas down-wind impacted by the fire-generated smoke and ash.

This section also discusses structure fires not associated with wildfires, and structure fires that develop following an earthquake. The section discusses these hazards in general terms first, and then provides an assessment, based on historical data and recent trends, of the likelihood of this hazard impacting the city of Santa Monica. Mitigation actions that the City has implemented over the years to reduce its fire hazard, and activities that could be implemented by the City and property owners are also addressed.

WILDFIRES
What are Wildfires?
Wildfires or wildland fires are fires that burn in natural areas, such as woodlands, forests, or grasslands. Wildland fire is a natural process and often a necessary part of the natural ecosystem in the western United States, including southern California. Many native plants require periodic burning to germinate and recycle nutrients that enrich the soils, and have a high oil content that makes them highly flammable. For example, some of the chaparral plants native to and common in the area, such as ceanothus, have heat-resistant seeds that sprout only after being exposed to fire.

Similarly, closed-cone coniferous trees have seed cones that only open after being exposed to heat.

The seeds themselves are protected by a thick coat of resin that insulates them. When the cones open, the seeds are released onto the ground, where they are more likely to sprout on rich, ashcovered soil that has been cleared of underbrush. Other native plants have fire-resistant roots that allow them to re-sprout quickly in recently burned areas.

These plant adaptations have developed over millennia in response to the region’s weather.

Specifically, the typically mild, wet winters characteristic of southern California’s Mediterranean climate result in an annual growth of grasses and plants that dry out during the hot summer months.

1 The area in between or consisting of a mix of urban and wildland zones.

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This dry vegetation then provides fuel for wildfires in the autumn, when the area is intermittently impacted by Santa Ana winds, the hot, dry winds that blow across the region predominantly in the late fall (see Section 11). These winds often fan and help spread wildland fires. It is important to note that wildfires in unpopulated areas are typically not considered a hazard unless the smoke and ash spread to populated areas, or the erosion following the fire silts up and impacts reservoirs used to store drinking water or generate hydroelectric power.

Wildfire Causes
Wildfires are typically caused either by lightning or by human actions. Lightning has been a significant cause of wildland fire in the western United States with approximately 44% of the wildfires in the region between 1992 and 2015 attributed to lightning strikes. Furthermore, these lightning-caused fires were responsible for 71% of the total area burned (Schartz and Penney, 20201F
2 ). These percentages vary, however, depending on several factors such as weather patterns, vegetation density, accessibility, and closeness to cities and towns. Thus, in California alone (rather than the entire western United States), for the period between 2010 and 2022, only about 14% of the wildland fires were caused by lightning, with human causes accounting for the remaining percentage. Moreover, in Los Angeles County, during this same time period, only 4% of the fires were caused by lightning, with humans being responsible for the remaining 96%. These data, compiled and graphed by Short (20222F
3 ) and published in the Wildfire Risk to Communities
webpage, are shown on Figure 10-1.

The more common human-caused fires are the result of a variety of accidental, intentional, or malicious activities. These include sparks from brush-clearing equipment and vehicles; improperly maintained or abandoned campfires; improperly disposed cigarettes; people (often children) misusing fire (such as matches or cigarette lighters); fireworks; firearms and explosives use; issues with power generation, transmission or distribution equipment; and arson (see categories on Figure 10-1). Downed or arcing power lines generally occur in response to strong winds, which is why electric utilities now often turn off power to high-risk areas during strong wind events (referred to as Public Safety Power Shutoffs, or PSPSs).

Figure 10-1 also shows that a large percentage of human-caused fires are categorized as undetermined, meaning that the post-fire investigation was inconclusive. Some of these fires may be the result of arson. Other causes that may be difficult to determine include the spontaneous combustion of oil-soaked rags, compost, manure piles, or baled hay; electrical charges from electrical fences surrounded by dry, flammable vegetation; refraction and magnification of sun rays by glass windows and mirrors; and embers associated with structural fires. Recently, a machinelearning model developed to predict the wildfire ignition cause based on physical, biological, social and management attributes of the fires was used to interpret the cause of more than 150,000 wildfires that occurred in the western United States between 1992 and 2020. The model attributed 21% of

2 Schwartz, J. and Penney, V., 2020, In the West, Lightning Grows as a Cause of Damaging Fires: The New York Times, article published Oct. 23, 2020; available from
https://www.nytimes.com/interactive/2020/10/23/climate/west-lightning-wildfires.html. 3 Short, K.C., 2022, Spatial wildfire occurrence data for the United States, 1992-2020 [FPA_FOD_20221014], 6th Edition: Forest Service Research Data Archive, Fort Collins, CO; available from https://doi.org/10.2737/RDS-2013- 0009.6.

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the fires to equipment and vehicle use, 20% to lightning, 18% to arson and incendiarism3F 4 , and 15%
to debris and open burning.4F
5 Figure 10-1: Wildfires Causes for the Period 2010-2020 in California (top) and in Los Angeles County (bottom) [From Short, 2022] As mentioned above, equipment and vehicle use are one of the leading causes of fires in California and Los Angeles County. A large number of fires are assigned to this category because this grouping includes a wide range of vehicles and equipment, from large construction rigs (bulldozers, tractors), to small equipment such as welders, grinders, chain saws and generators. Typically, these fires are the result of mechanical or electrical malfunction or failure of the equipment, but they can also be the result of misuse or carelessness, such as dragging chains or metal objects in rocky or hard terrain, causing sparks that then ignite vegetation. Vehicular collisions, flat tires, spillage of fuel during refueling operations, and driving vehicles across dry vegetation can also result in wildfires5F 6 .

Other significant causes of wildfires are burning piles of debris in the open (such as yard debris, open trash burning, and land clearing), and campground fires that are either improperly contained or improperly extinguished. An open fire can escape in a matter of minutes if not attended properly, if the area around the burn has not been cleared appropriately, and/or if fire suppression tools or equipment (such as shovels, water hoses or water pumps) are not available to immediately put out

4 Both arson and incendiarism refer to fires started intentionally, but arson refers to setting property on fire for the purpose of causing damage. Fires started by persons experiencing homelessness for the purposes of cooking and/or keeping warm likely fall under the incendiarism category. 5 Pourmohamad, Y., Abatzoglou, J.T., Fleishmna, E., Short, K.C., Shuman, J., AghaKouchak, A., et al. 2025, Inference of wildfire causes from their physical, biological, social and management attributes: Earth’s Future, Vol. 13, paper e2024EF005187, doi:10.1029/2024EF005187. 6
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any flying embers. Open burns and campground fires should never be started in windy, dry conditions.

Arson is the fourth leading cause of wildland fires in California, and the third leading cause in Los Angeles County (Figure 10-1). Arson is the malicious or deliberate act of setting property or public lands on fire with the intent to cause damage or defraud. Under California Penal Code, arson is a crime punishable with imprisonment in jail. The arsonist may also be held responsible for all costs related to the suppression of the fire, damages incurred, and rehabilitation of the burnt land.6F 7 History of Wildfires Near Santa Monica and In Southern California As mentioned above, large fires have been part of the southern California landscape for millennia.

Based on oral histories, it is known that Indigenous peoples in California relied on fire to reduce fuel load and improve their ability to hunt and forage.7F
8 Stephens et al. (20078F9
) used ethnographic studies,
combined with dendrochronology analyses and other data on fire history, to estimate that before the 1800s, between about 4.5% and 12% of the state burned every year as a result of both lightninggenerated wildfires and fires set by Indigenous groups.

The first wildfire in the official historical record of wildfire statistics in Los Angeles County dates to September 1878. The fire reportedly burned the San Rafael Hills, a large section of the Verdugo Hills and into the Sierra Madre Mountains. The actual extent of the fire is unknown, and the data available suggest that there were several burns rather than one massive fire. Another series of burns that were erroneously grouped together and presented as the largest fire in Orange County’s history occurred in September 1889. These fires appear to have been confined to two main but separate areas, namely the foothills of the Santa Ana Mountains in what is now the city of Orange, and the Rancho Santa Margarita area in northern San Diego County.9F
10 In Los Angeles County, wildland fires typically occur in the undeveloped or slightly developed portions of the hills and mountains that surround the extensively developed basin. Areas in the County specifically known for their high to very high wildland fire susceptibility include Malibu, Calabasas, Glendale, Burbank, and the mountainous regions of La Cañada Flintridge, Altadena, Pasadena, and Sierra Madre. Wildland fires have also occurred historically in the Baldwin Hills and in Palos Verdes Hills, impacting the cities and communities therein.

Figure 10-2 shows those areas in the Santa Monica Mountains to the northwest, north and northeast of Santa Monica, and in the northwestern Baldwin Hills, to the east-southeast of the city, that have burned at least once between 1930 and March 2025, based on data available from the California Department of Forestry and Fire Protection (CAL FIRE10F 11). The figure shows areas that have burned

7 https://www.nifc.gov/fire-information/fire-prevention-education-mitigation/wildfire-investigation 8 e.g., Anderson, M.K., 2005, Tending the Wild: Native American Knowledge and the Management of California’s Natural Resources: University of California Press, Berkeley, California, 526p. 9 Stephens, S.L., Martin, R.E., and Clinton, N.E., 2007, Prehistoric fire area and emissions from California’s forests, woodlands, shrublands, and grasslands: Forest Ecology and Management, doi:10.1016/j.foreco.2007.06.005. 10 Goforth, B.R. and Minnich, R.A., 2007, Evidence, exaggeration, and error in historical accounts of chaparral wildfires in California: Ecological Applications, Vol. 17, No. 3, pp. 779-790. 11 http://frap.cdf.ca.gov/data/frapgisdata/select.asp; https://www.fire.ca.gov/what-we-do/fire-resource-assessmentprogram/gis-mapping-and-dataanalytics#:~:text=Unlocking%20Insights%20with%20GIS%20Mapping%20The%20Fire,the%20health%20of%2 0California%27s%20forests%20and%20rangelands.

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at least once during a 20-year period. Overlap of some of these burnt areas indicates that wildland fire has impacted some of the same areas more than once during the time period covered.

Significantly, Figure 10-2 shows that in nearly 100 years, no wildland fires have occurred in Santa Monica proper, although a few fires have been contained very close to the northern city boundary.

The most recent and impactful of these is the Palisades fire that occurred in January 2025. The area burned by this fire, and its location relative to Santa Monica, is shown by the area with horizontal red lines shown on Figure 10-2 below.

Figure 10-2: Historical (1930-2025) Wildfires Near Santa Monica (For a larger version of this figure refer to Plate H-16 in Appendix H) Based on the historical record, the risk of wildland fire in Santa Monica has traditionally been considered low to nil. However, hotter temperatures, drier conditions, and increased drought brought on by climate change have already increased the fire risk and lengthened the fire season in most areas of the United States, including southern California11F

12. The 2025 Palisades fire has shown
that a wildland fire in the Santa Monica Mountains during an intense drought period, especially if fanned by Santa Ana winds coming from the east to northeast, could encroach onto Santa Monica, placing the structures in the northern portion of the city in danger. This is discussed further in this section.

12 https://www.c2es.org/content/wildfires-and-climate-change/ accessed May 24, 2024; Khorshidi, M.S., Dennison, P.E., Nikoo, M.R., AghaKouchak, A., Luce, C.H., and Sadegh, M., 2020, Increasing concurrence of wildfire drivers tripled megafire critical danger days in Southern California between 1982 and 2018: Environmental Research Letters, Vol. 15, No. 10, Paper No. 104002, doi:10.1088/1748‐9326/abae9e.

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Table 10-1 lists the twenty most destructive fires in California to date, based on statistics collected and published by CAL FIRE. The table shows that 18 of the 20 most destructive fires in California occurred in the past 25 years (since the year 2000), with 15 of these having occurred since 2015.

These data highlight the fact that the fire risk in California has increased in the recent past as a result of both climate change and increased construction in the WUI.12F 13 Some of these fires, and others no
longer considered the most destructive but that effected change in the form of modifications to the fire and building codes, are described further in the sub-sections below. Also included in the subsections below are three of the largest fires that have occurred historically near Santa Monica.

Table 10-1: Top Twenty Most-Destructive Fires in California (as of April 3, 2025) Based on Total Number of Structures Destroyed
No. Fire Name (cause) Date County Acres Structures Deaths 1 Camp (powerlines) November
2018 Butte 153,336 18,804 85
2 Eaton (under
investigation, likely power
line)*
January
2025 Los Angeles 14,021 9,414 18
3 Palisades
(under investigation,
likely human related)*
January
2025 Los Angeles 23,448 6,837 12
4 Tubbs (electrical) October
2017 Napa & Sonoma 36,807 5,636 22
5 Tunnel – Oakland Hills
(rekindle)
October
1991 Alameda 1,600 2,900 25
6 Cedar
(human related)
October
2003 San Diego 273,246 2,820 15
7 North Complex (lightning) August
2020 Butte, Plumas & Yuba 318,935 2,352 15
8 Valley (electrical) September
2015 Lake, Napa & Sonoma 76,067 1,955 4
9 Witch (power line) October
2007 San Diego 197,990 1,650 2
10 Woolsey (electrical) November
2018 Ventura 96,949 1,643 3
11 Carr (human related) July 2018 Shasta & Trinity 229,651 1,614 8 12 Glass (undetermined) September
2020 Napa & Sonoma 67,484 1,520 0
13 LNU Lightning Complex
(lightning/arson)
August
2020
Napa, Solano,
Sonoma, Yolo, Lake &
Colusa
363,220 1,491 6
14 CZU Lightning Complex
(lightning)
August
2020
Santa Cruz & San
Mateo 86,509 1,490 1
15 Nuns (power line) October
2017 Sonoma 54,382 1,355 3

13 By some accounts, about 45% of new construction in California between 1990 and 2020 was at the WUI (https://silvis.forest.wisc.edu/data/wui-change/ as reported in https://calmatters.org/housing/2025/01/ca-wuihousingpolicy/#:~:text=Between%201990%20and%202020%2C%20nearly%2045%%20of,of%20all%20the%20land% 20in%20the%20state; both accessed May 12, 2025).

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No. Fire Name (cause) Date County Acres Structures Deaths 16 Dixie (power line) July 2021 Butte, Plumas, Lassen,
Shasta & Tehama 963,309 1,311 1
17 Thomas (power line) December
2017
Ventura & Santa
Barbara 281,893 1,063 2
18 Caldor
(human related?,
under investigation)
September
2021
Alpine, Amador &
El Dorado 221,774 1,003 1
19 Old (human related) October
2003 San Bernardino 91,281 1,003 6
20 Jones (undetermined) October
1999 Shasta 26,200 954 1
Sources: CAL FIRE website accessed in May 2024, February 2025, and April 2025: https://34c031f8-c9fd-4018-8c5a4159cdff6b0d-cdn-endpoint.azureedge.net/-/media/calfire-website/our-impact/firestatistics/top20_destruction.pdf?rev=adaea8332a014a7ebf11dc6fdb3f8e98&hash=EA9A8C492BD9FBAA0FB67C2FEA3F F52E
*CAL FIRE indicates that these numbers are preliminary, based on aerial assessments. Validated inspections are being conducted by Damage Assessment teams as of the writing of this report, so these totals may change slightly.

Topanga Canyon or Santa Monica Mountains Fire of 1938
This fire began on November 23rd and burned for a week. The area covered by this fire is shown in light purple on Figure 10-2. The fire began at the Trippet Ranch, about three miles from the mouth of Topanga Canyon, in the city of Los Angeles, when the ranch caretaker disposed of ashes thought to be inert onto the edge of the brush. Live coals in the ashes were fanned by high winds and because of the extremely low humidity at the time, the fire spread quickly. The Los Angeles Fire Department, upon realizing the severity of the fire, responded with dozens of engines and trucks, and hundreds of crew members13F

14. Except for many homes along the beach, most of the area burned was uninhabited. The fire department took measures to protect the homes exposed both along the beach lines, and along the southerly and easterly limits of the burn area. According to the after-fire report14F 15, the fire did not
cross Sunset Boulevard, but it did burn close to it at many points. As a result, only a handful of dwellings, stables, sheds, and garages were damaged. The total building loss, including contents, was reported as $19,228.25 (equivalent to about $428,000 in 2024 dollars).

The need for medical services at the scene of the fire was noticed almost immediately. In response, one of the city’s first aid ambulances was stationed at Pacific Palisades. The American Red Cross also responded very early on providing equipment and personnel to help with the firemen injured.

Although November 24th began a holiday weekend, the fire department received assistance from hundreds of volunteers, and assistance from many other government agencies, including the City of Los Angeles Department of Water and Power that provided a bus and several trucks to transport men and equipment to the front lines, in addition to bulldozers. In the post-fire analysis, the Chief Engineer, Mr. R.J. Scott, recommended that the “large water supply main be continued from its present terminus on Mulholland Highway, … and that laterals be run from this main along each existing and contemplated fire road.” He also recommended building additional roads through the

14 http://www.lafire.com/famous_fires/1938-1123_1938BrushFire/112338_BrushFire.htm, accessed on May 27, 2024. 15 Ibid
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region; the regular upkeep of the existing firebreaks; and acquisition of caterpillars, bulldozers, and large trucks to transport men and equipment.

Bel Air, Brentwood and Santa Ynez Fires of 1961
The first of these fires began on November 6th, 1961 on the north slope of the Santa Monica Mountains, and fanned by strong southerly and westerly Santa Ana winds burned to the top of the mountains and then south, eventually jumping across Mulholland Drive and into Stone Canyon. A second, short-lived fire was started by arson in Benedict Canyon; followed by a third fire south of Mulholland Drive near Topanga Canyon that burned in a southeasterly direction15F

16. This third fire is
referred to as the Santa Ynez fire. Vegetation in the region was tinder dry as a result of several years of drought. The area covered by these fires is shown in the darker green on Figure 10-2.

At the time in the Bel Air-Brentwood area, shingle and shake roofs were predominant. That, together with the dry conditions, hot temperatures, strong wind conditions, narrow winding roads, and difficult terrain, combined to create a disastrous brush fire. The Bel Air-Brentwood fire burned more than 6,000 acres, a small number compared to most of the other fires in Table 10-1, but it destroyed 484 residences and damaged another 21 buildings. Fortunately, no lives were lost, and there were no major injuries. The total building loss was not provided in the sources reviewed, but the cost of the houses destroyed was estimated to range between $35,000 and $700,000 apiece ($367,000 to $7.3 million in 2024 dollars). The Santa Ynez fire burned 8,560 acres of brush lands and destroyed nine buildings16F

17. The post-fire analysis17F
18 of the Bel Air-Brentwood fires found that 75% of the buildings destroyed had wood roof coverings, with the combustible roofs being a major point of ignition. The investigation also found that although less than 3% of the buildings in the area were stilted or cantilevered on steep slopes, 44.5% of buildings with this structural feature suffered substantial damage. Large, unprotected eaves and exposed floors in these structures allowed the fire to impact the buildings.

More than 45% of the houses located on hilltops were destroyed, and about 70% of the ruined homes were located within 50 feet of natural vegetation, with inadequate clearance around the structures.

Los Angeles Fires of 1978
On October 23, 1978, at least ten wildfires started in different areas of southern California. Because the region was experiencing strong Santa Ana winds, many of these fires spread quickly, burning thousands of acres. These fires included: 1) a fire in Mandeville Canyon that is described in more detail below, 2) four brush fires in San Dimas, 3) a fire in Chino that spread into Carbon Canyon in Orange County (which may be related to a fire that reportedly began in the Elsinore-Perris region), 4) a fire in Agoura also described further below, 5) a fire in Agua Dulce, 6) a fire in Glendale, and 7) a brush fire north of Sierra Madre that impacted mostly the San Gabriel Mountains.

The Mandeville Canyon fire was first reported at 9:41 AM on October 23rd; emergency officials declared it a major emergency within the first hour due to its fast spread. The fire reportedly began near the intersection of Sepulveda Boulevard and Mulholland Drive, and quickly spread west

16 https://www.lafire.com/famous_fires/1961-1106_BelAirFire/1961-1106_LAFD-Report_BelAirFire.htm, accessed May 27, 2024. 17 Ibid 18 Ibid
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through Kenter, Mandeville, Sullivan, Rustic, Temescal and Santa Ynez Canyons, reaching the Pacific Coast Highway (PCH) in about two hours, prompting the evacuation of sections of Pacific Palisades and Malibu (light green area on Figure 10-2 north of Santa Monica). The ensuing heavy traffic load on Sunset Boulevard impacted emergency vehicles response.18F 19 This fire reportedly
burned an estimated 6,130 acres, destroyed 30 homes and damaged another 18 in Pacific Palisades.19F
20 In Pacific Palisades the fire reportedly also destroyed the St. Matthew’s Episcopal Church built in 1941, and the mill building. At the Boy Scout Camp in upper Rustic Canyon, the ranger’s house was destroyed, together with several other buildings, but the Main Lodge survived. Other significant buildings that were destroyed include a guest house at the Presbyterian Conference grounds, the Josepho and Murphy Ranches, and the Will Rogers get-away cabin.20F 21 The cause of the
Mandeville fire was power lines that were downed by the strong winds. The City of Los Angeles was deemed liable and ultimately paid $8.5 million to 22 Mandeville Canyon residents and eight insurance companies.21F
22 The Agoura fire, referred to as the Agoura-Malibu fire, or the Agoura-Malibu firestorm, was started around noon on October 23rd by a 15-year-old who used a lit cigarette wrapped in a matchbook as an incendiary device. The fire was first reported in Agoura at 12:11 PM, and by 2:30 PM, it had reached Broad Beach in Malibu. The fire continued to burn through the canyons in the Santa Monica Mountains for four days, with the total burned area estimated at 25,000 acres. Agoura residents evacuated to a shopping center next to the 101 Freeway in Agoura Hills. The juvenile that started the fire was arrested and sentenced to jail until his 21st birthday, confined in the California Youth Authority.22F
23 The Mandeville Canyon and Agoura-Malibu fires combined appear to have destroyed 230 homes and damaged at least another 254 structures, resulted in three civilian fatalities, and approximately 50 civilian injuries. Damage was estimated at $71.4 million (approximately equivalent to $343.5 million in 2024).

Tunnel Fire of 1991 (Oakland Firestorm)
This is still the fifth worst fire in California, according to the statistics presented on Table 10-1. This large suburban fire at the WUI occurred in the hillsides of northeastern Oakland and southeastern Berkeley on October 19-22, 1991. Firefighters responded to a grass fire northeast of the intersection of State Routes 24 and 13 on October 19th that by the end of the day was thought to be under control.

However, on the morning of the 20th a single ember blew into a tree; the tree caught fire, and the flames fanned by strong wind gusts moved quickly to the southwest. Burning embers carried by the winds ignited fires ahead of the original burn, eventually igniting hundreds of structures.

Firefighting efforts were hampered by several factors including: high heat and strong wind gusts that caused the fire to spread quickly; damage to power lines that serviced 17 of the pumping stations in the Oakland water system resulted in several emptied reservoirs to go unfilled; compatibility issues with the equipment used by responding fire departments from other counties not matching the fire hydrant outlets; antiquated communications equipment; narrow, winding roads crowded with

19 https://www.circlingthenews.com/the-1978-blaze-destroyed-25-homes-and-st-matthews-church/, accessed on May 7, 2025. 20 Ibid 21 Ibid. 22 https://www.newspapers.com/article/the-los-angeles-times-la-must-pay-85/94877101/ accessed May 8, 2025. 23 https://en.wikipedia.org/wiki/1978_Agoura-Malibu_firestorm accessed May 8, 2025.

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parked cars, many in front of fire hydrants; thick, dry vegetation; and widespread occurrence of wood shake or wood shingle roofs.23F
24 The fire burned only about 1,600 acres, but destroyed about 2,900 structures, including 2,843 single-family dwellings and 433 apartment and condominium units, damaged another 193 singlefamily dwellings, killed 25 people and injured 150 others. Losses associated with the fire were estimated at $1.537 billion ($3.54 billion in 2024 dollars). In response to this fire, the California Fire Code was modified to include regulations regarding defensible space around buildings. The California Building Code now also requires fire-resistant construction materials for all new structures at the WUI. The lessons learned from this fire also created the foundation for the “Incident Command System,” the process of organizing and managing multi-jurisdictional emergencies that is still utilized today.24F
25 Laguna Fire of 1993
The Laguna or Laguna Canyon fire occurred on October 27-31, 1994 in Orange County. As with the other fires summarized here, abundant flammable, dry vegetation following several years of drought, strong Santa Ana winds, and extensive development at the WUI combined to create the perfect conditions for a small vegetation fire to intensify quickly, spreading through the canyons at a rate of about 100 acres per minute, and at one point burning four structures every minute. The flames reportedly were routinely 40 to 50 feet high, and at times more than 200 feet high. The fire spread so quickly that the fire department’s objectives soon switched from structure defense to saving lives and protecting downtown Laguna Beach. The entire population of Laguna Beach, approximately 24,500 people, were under evacuation orders.

The fire burned more than 16,000 acres and destroyed 441 structures. Amazingly, no fatalities and only eight injuries were reported. Total losses in property damage were estimated at $528 million ($1.14 billion in 2024 dollars). Following the fire, because six of the 22 reservoirs in the area were completely drained by the firefighting efforts, the water district built two new reservoirs, and also purchased additional backup generators and pumps. The City of Laguna Beach strengthened building codes, requiring that all new homes have automatic sprinkler systems and fire-retardant roof coverings, and expanded a vegetation management program that uses goats year-round.25F 26 Southern California Fires of 2003, Including Cedar Fire The fall of 2003 marked one of the most destructive wildfire seasons in California history (in terms of acreage burned). In a ten-day period, 12 separate fires raged across southern California in Los Angeles, Riverside, San Bernardino, San Diego and Ventura counties. This fire season followed five years of unusually dry conditions in southern California, with rainfall totals gaged at between 50 and 75% of normal levels.

The massive “Cedar” fire in San Diego County alone consumed 3,241 structures (2,800 homes) and burned more than 270,000 acres.26F
27 It still ranks in the upper six most-destructive wildland fires in

24 http://www.sfmuseum.org/oakfire/overview.html and https://en.wikipedia.org/wiki/Oakland_firestorm_of_1991, accessed May 27, 2024. 25 Cole, D., 2000, The Incident Command System: A 25-Year Evaluation by California Practitioners; available at https://apps.usfa.fema.gov/pdf/efop/efo31023.pdf. 26 https://en.wikipedia.org/wiki/Laguna_Fire_(1993), accessed May 27, 2004. 27 https://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5297020.pdf, accessed May 27, 2024.

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the state (see Table 10-1). The fire was started on October 25th by a hunter lost in the Cleveland National Forest who lit a fire to signal for help, with the fire quickly spreading out of control.

Between midnight and 3:00 AM on the 26th, the fire had spread from 5,500 acres to 62,000 acres, burning a southwesterly path toward the city of San Diego at a rate of between 3,600 and 6,000 acres per hour. The fire killed 12 people in Wildcat Canyon and Muth Valley, and destroyed 39 homes on the Barona Indian Reservation. On the 26th, at 5:00 AM, the fire reached Poway, destroying 54 homes and 16 businesses, and continued westward impacting several communities in north and east San Diego. By noon, hundreds of homes in the Scripps Ranch community were burning. On the 27th, the fire burned hundreds of additional homes in several bedroom communities near San Diego before the winds changed direction, causing the fire to advance to the east. The fire reached the communities of Cuyamaca and Julian in the early hours of the 28th, destroying more than 500 homes in its path. On the 29th, the fire reached the Riverwood Estates, a community near Santa Ysabel where a group of firefighters were trapped and overrun by the fire. One firefighter died and three others were injured. Containment was achieved on November 3rd, but it took until December 5th before the fire was completely under control. In total, 15 people died; at least ten of those died in their cars as they were trying to flee the flames. Losses related to this fire were estimated at $1.3 billion27F
28 (approximately $2.21 billion in 2024 dollars).

Tubbs Fire of 2017
As of April 2025, the Tubbs fire ranks as the fourth most-destructive fire in California history. The fire began on October 8, 2017 north of Calistoga, and within hours, fanned by winds 20 to 70 miles per hour, had travelled more than 12 miles into densely populated areas of the town of Santa Rosa.

The fire then leaped across Highway 101 and destroyed more than 1,300 homes in the Coffey Park subdivision. On October 10th, winds changed direction and on the 11th, the entire town of Calistoga was evacuated. The fire was not fully contained until October 31st. The fire, which is now known to have been caused by a private electrical system, burned more than 36,800 acres, destroyed more than 5,600 homes, and killed 22 people. Tens of thousands of people were evacuated in and around Santa Rosa. This was one of more than a dozen wildfires that were burning in northern California at the same time. In total, these fires destroyed more than 7,000 structures, burned about 160,000 acres, and killed more than 40 people.28F
29 The fire damage in Santa Rosa alone was estimated at $1.2 billion ($1.54 billion in 2024 dollars), with an estimated 5% of its housing stock destroyed.29F 30 The Tubbs fire also destroyed several
commercial structures, including the Fountaingrove Inn, the Fountaingrove Round Barn, a Hilton hotel, a Kmart store, the Redwood Adventist Academy, the Fountaingrove campus of Keysight Technologies, and the Santa Rosa Community Health’s Vista Campus. Several medical centers had to be evacuated, including the Kaiser Permanente and Sutter Health facilities in Santa Rosa.

The fire destroyed an entire subdivision in Fountaingrove that was surrounded by a 100-foot wide fire break, and where the homes were built with fire-resistant siding, roofing and deck materials, including the use of protected eaves to keep windblown embers from entering the structures.30F 31 The
deathly toll of the Tubbs fire was attributed to hurricane-force winds, above-normal rainfall earlier

28 https://en.wikipedia.org/wiki/Cedar_Fire, accessed May 27-28, 2024. 29 https://theconversation.com/why-were-californias-wine-country-fires-so-destructive-86043, accessed May 28, 2024. 30 https://en.wikipedia.org/wiki/Tubbs_Fire#, accessed May 28, 2024. 31 Ibid Local Hazard Mitigation Plan Section 10
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in the year that resulted in increased grass growth, which in turn made the fire very intense, and increased population at the WUI, with a high density of homes in the area.31F 32 Camp Fire of 2018
The most-damaging and most-deadly fire to date in California’s history began on November 8th, 2018 when a poorly maintained electric transmission line was downed by strong winds, causing a brush fire by Camp Creek Road, near Pulga, in northern California. The conditions at that time included a heavy cover of unusually dry vegetation due to a wet spring, followed by drought in the fall, and low humidity (10%) associated with hot, dry gusty winds locally called Jarbo winds (similar to the Santa Ana winds in southern California). The area impacted had last burned in 2008, and could only be accessed via winding roads with sharp curves, steep adjacent slopes and inadequate shoulders.32F
33 Because high winds and low humidity had been forecasted, Pacific Gas & Electric (PG&E) had notified customers in the area that they would probably shut down electric power. However, the line that failed could only be de-energized manually, and that had not been done the morning that the fire began. The fire was noticed by PG&E Rock Creek Powerhouse personnel soon after it began, but the mountain road near where the fire began was too narrow for fire engines to navigate, and it was too early in the morning and too windy for air resources to be deployed. The fire quickly grew, and by 7 AM had reached the community of Concow. By 8 AM, the fire had reached the town of Paradise; 95% of the structures in both of these communities were lost in the first six hours after the fire began, before evacuation orders were issued. Loss of 17 cell towers and a series of failures in the emergency alert system meant that 25-94% of the emergency alerts issued in the first few hours failed to reach the residents in the impacted areas. Other communities impacted include Pulga, Magalia, Centerville, Butte Valley, Chico, Forest Ranch, Helltown, Inskip, Oroville, and Stirling City.33F
34 Full containment of the fire was announced on November 25th, with a total burn area of nearly 154,000 acres. The total number of destroyed structures is officially set at 18,804; most of these were homes, but the list also includes five public schools in Paradise, a large shopping center, several restaurants and numerous small businesses, churches, and part of the Feather River hospital.

The fire killed 85 civilians and injured 17. The injury count includes five firefighters. A large number of deaths (70) occurred inside or immediately outside victim’s homes, and seven people died trapped in their vehicles while trying to evacuate.34F
35 The total cost of this fire is still being determined. In addition to the property loss, cleanup of the fire debris is considered the largest hazardous cleanup effort in California history (although this could be surpassed by the costs of cleaning up the Eaton and Palisades fires). Contaminants related to the burned structures and burned plastic pipes soaked into the ground and contaminated surface waters with high levels of heavy metals, dioxins, and benzene, to mention a few. The large number of insurance claims caused the Merced Property and Casualty Company, a small insurer, to become

32 https://theconversation.com/why-were-californias-wine-country-fires-so-destructive-86043, accessed May 28, 2024. 33 https://en.wikipedia.org/wiki/Camp_Fire_(2018), accessed May 27-28, 2024. 34 Ibid 35 Ibid and https://34c031f8-c9fd-4018-8c5a-4159cdff6b0d-cdn-endpoint.azureedge.net/-/media/calfirewebsite/our-impact/fire-statistics/top-20-destructive-cawildfires.pdf?rev=3f619258cab84b34b680ce521d615525&hash=6C6AD8F9377A31117DF437BBDBE68F07 Local Hazard Mitigation Plan Section 10
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insolvent. Anticipating liabilities in the billions of dollars as a result of the 2015 Butte fire, the 2017 North Bay fires (which include the Tubbs fire), and the 2018 Camp fire, PG&E filed for bankruptcy protection and reorganization. The utilities company has since settled, paying $1 billion to state and local governments, $11 billion to insurance carriers and investment funds, and $13.5 billion for other claims handled through the PG&E Fire Victim Trust.35F 36 Woolsey Fire of 2018
The Woolsey fire ignited on November 8th, 2018, the same day that the Camp fire ignited in northern California (see entry above). The wildfire started in Woolsey Canyon, in the Santa Susana Mountains above Simi Valley, near the boundary between Los Angeles and Ventura counties, on Boeing-owned property of the Santa Susana Field Laboratory. Other smaller wildfires that began the same day in southern California impacted response to this one, as described further below.

Southern California Edison reported an outage in their Big Rock 16 kV circuit about 2 minutes before a brush fire at the same location was first reported. Because Ventura County first-responder resources were assigned to both the Borderline Bar and Grill shooting that had occurred the evening prior, and to the Hill fire that was burning nearby, it took almost 20 minutes for the first firefighters to respond to the area where the Wooley fire was burning. Staff with a private firefighting company contracted by Boeing to protect their Field Laboratory were also delayed because their engine broke down. 36F
37 Strong Santa Ana winds fanned the fire, spreading it quickly toward the south; the fire crossed the 101 Freeway near Calabasas, and into the Agoura Hills and Santa Monica Mountains during the night and the early morning hours of November 9th. Due to the strong winds, aerial suppression could only begin at about 5 AM on November 9th. However, the fire continued to spread through the mountains south of the 101 Freeway, reaching PCH in Malibu that afternoon. The fire also spread west to areas of Thousand Oaks and Westlake Village, and east-southeast, to the West Hills neighborhood of Los Angeles. Firefighting units from CAL FIRE and the United States Forest Service were deployed to fight the fire, with an estimated 3,242 firefighters assigned to this blaze by November 10th. By then the fire had burned more than 70,000 acres, forcing the evacuation of nearly 300,000 residents, including total evacuation of Bell Canyon, Malibu, Agoura Hills, the community of Malibou Lake, and Oak Park. Strong winds in the early morning hours of November 14th caused the fire to flare in the rugged mountains at the western end of the Santa Monica Mountains, in a slightly populated area with scattered homes. The fire was declared fully contained at 6:11 PM on November 21st
.

The Woolsey fire destroyed 1,643 structures, including about 1,600 houses, and damaged another 364 structures.37F
38 Several filming locations and historical sites were impacted by the fire, with the Santa Monica Mountains National Recreation Area (SMMNRA) sustaining significant damage.

Specifically, about 88% of National Park Service lands within the SMMNRA burned38F 39, forcing the
closure of many trails in the park for many months to allow the area to recover. In total, 96,949 acres of land burned. Two people died inside their vehicle on Mullholland Highway, and another body was found in Agoura Hills. Charred human remains found in Malibu on January 22, 2019

36 Ibid. 37 https://en.wikipedia.org/wiki/Woolsey_Fire, accessed April 25, 2025. 38 Ibid 39 https://www.nps.gov/samo/learn/management/2018-woolsey-fire.htm, accessed April 25, 2025.

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suggest a fourth victim. Two of the 13 mountain lions fitted with radio collars in the Santa Monica Mountains also died as a result of the Woolsey fire. The damage caused by this fire was estimated at $6 billion in 2018 dollars (approximately equivalent to $7.5 billion in 2024).

City of Santa Monica staff assisted with the evacuation of the Santa Monica Mountains on November 9th. Santa Monica’s main focus was to support evacuations along PCH, closing entry points into Santa Monica that could slow-down the evacuation traffic. City of Malibu staff evacuated civic buildings in downtown Malibu, and on November 10th, the Malibu Emergency Operations Center (EOC) was relocated to the Santa Monica EOC and remained there for almost three weeks. Santa Monica personnel supported Malibu’s EOC, especially in public communications and emergency management roles. Santa Monica High School’s gymnasium was activated as a shelter and also hosted the event’s community meeting for persons impacted by the fire.

Franklin (Malibu) Fire of 2024
This wildfire began at 10:50 PM on December 9th, 2024 along Malibu Canyon Road, in Malibu Creek State Park and over the next day burned approximately 2,600 acres, fanned by Santa Ana winds. The fire burned and destroyed at least 20 buildings, and damaged 28 others39F 40, forced
thousands of Malibu residents to evacuate, and extended into the campus of Pepperdine University, where students sheltered in place. Ultimately, the fire burned 4,037 acres, and was finally contained in the evening of December 18th. As of this writing, its cause was under investigation. Although windy, helicopters with night-vision capabilities were able to fly most of the night during the first night, directing crews to the most critical areas. Two large air tankers were brought in the next morning to help with the firefighting operations. The winds died down by the afternoon of the 10th, allowing fire fighters to use more planes and helicopters to fight the blaze. On the ground, approximately 2,000 fire fighters were assigned to this event. The American Red Cross set up a shelter in Santa Monica, at the Child Development Services building on Ocean Park Boulevard. The shelter hosted approximately 7 persons and their pets during the event. The Franklin fire was declared 100% contained on December 18 at 8:00 PM.

Palisades Fire of 2025
The Palisades fire is currently considered the third most-damaging historical fire in California based on the number of structures destroyed. The fire was first reported just before 10:30 AM on Tuesday, January 7, 2025 in the mountains behind Pacific Palisades. When the fire was first reported it probably covered about 10 acres, but within 20 minutes it is estimated it had grown to 200 acres, and by around 2 PM it covered more than 700 acres. An hour later, it had nearly doubled to 1,262 acres, and by 12:29 AM on January 8th, CAL FIRE reported the fire had grown to 2,921 acres. The fire continued to grow at an accelerated rate through the day, with CAL FIRE reporting at 11:10 PM that evening that the fire had grown to 17,234 acres. On January 8, 2025, a spot fire on the southern edge of the fire destroyed several homes approximately 2,000 feet from the Santa Monica/Los Angeles border, with the fire quickly spreading from structure to structure.

By the morning of January 9th, the fire authorities reported that more than 5,300 structures had been destroyed and nearly 20,000 acres had burned. The fire continued burning throughout the day but at a much lower pace, with a status report issued by CAL FIRE at 7:39 AM on January 10th indicating that the fire had grown to 20,438 acres. At 8:00 AM it was reported that the fire was about 8%

40 https://en.wikipedia.org/wiki/Franklin_Fire, accessed April 25, 2025.

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contained. At 2:33 PM a new status report indicated that the area impacted was 21,317 acres, with containment still at 8%. CAL FIRE reported at 8:00 AM on January 11th that the fire had grown another 1,000 acres overnight, and by 4:37 PM that afternoon, the burned area had been updated to 23,654 acres, with the fire burning towards Mandeville Canyon, Encino, Tarzana, and the western portion of Bel Air. After the 11th, the fire did not grow any more, but it took fire fighters nearly 20 more days before the fire was considered fully contained. 100% containment was reported on January 31st
.

The cause of the fire is still under investigation, but its fast growth was the result of the strong Santa Ana winds, moderate drought conditions in the area due to a lack of any measurable precipitation for at least the prior eight months, and dense brush resulting from decades-long effective fire suppression efforts that meant a large part of the wildland area that ultimately burned had not burned since the 1940s. As a result of these conditions, the National Weather Service had issued a rare “potentially dangerous situation” Red Flag Warning the day before, effective from noon on Tuesday, January 7th through 4:00 PM on Wednesday, January 8th.40F 41 As a result of this warning, Caltrans had
closed several roads in the fire-warning area, CAL FIRE had positioned several firefighting assets around southern California, and the Los Angeles Department of Water & Power had topped off their three 1-million-gallon water tanks in the area. Filling up the water tanks unfortunately proved to be insufficient, with an estimated 20% of the fire hydrants in the higher-elevation areas of Pacific Palisades running out of water.41F
42 The 117-million-gallon Santa Ynez reservoir in Pacific Palisades was being repaired and out of commission when the fire started. Had this reservoir been online, it is anticipated that the water therein could have temporarily helped to fight the fires, although many specialists indicate that the water infrastructure is not designed to fight these regionally extensive fires42F
43 and the impact that this reservoir could have had would have been relatively minor. The Red Flag Warnings were extended through January 23rd.

The damage caused by the Palisades fire is still being assessed, with a total cost not likely to be known for several years. Building safety assessments of the area burned indicates that 6,837 structures were destroyed, and another 973 structures were damaged. The total death toll is currently at 12 people; four injuries were also reported, with one of those being a firefighter. Most of Pacific Palisades north of Sunset Boulevard burned, including several architecturally significant residences, at least three churches, the Palisades branch of the Los Angeles Public Library, and several elementary schools. Several buildings that were part of the Palisades Charter High School were also destroyed, but the administration and main classroom buildings survived. The building housing the Getty Villa was not damaged thanks to museum staff actively patrolling the grounds throughout the night with fire extinguishers on hand, dousing embers that landed onsite. Several structures at the Will Rogers State Historic Park and Topanga State Park were also destroyed. Smoke from the Palisades fire and several other fires that were burning at the same time in the region impacted air quality in a large portion of the Los Angeles basin. Residents were advised to wear masks and sensitive individuals were encouraged to stay inside as much as possible.

The Palisades fire prompted wildfire evacuation orders for the city of Santa Monica, the first in the city’s history. Given the strong winds and wind direction, firefighters were concerned that the

41 https://www.dailynews.com/2025/01/06/santa-ana-winds-could-gust-60-90-mph-in-some-southern-californiaareas-boosting-fire-danger/, accessed June 18, 2025. 42 https://en.wikipedia.org/wiki/Palisades_Fire, accessed April 25-28, 2025. 43 https://www.nbcnews.com/news/us-news/reservoir-pacific-palisades-was-commission-fire-started-rcna187217, accessed April 28, 2025.

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Palisades fire could reach the northern part of the city, either through Sullivan/Rustic Canyon, or from fire in Mandeville Canyon burning south and west through Santa Monica Canyon. At the same time, several brushfires that had ignited along the Santa Monica bluffs and off the I-10 Freeway, within Santa Monica city limits, were straining the firefighting resources in the city. As a result, at 7:24 PM on January 7th, the City of Santa Monica implemented a mandatory evacuation order for the most northerly parts of the city, from San Vicente Boulevard north to the city limits, extending from the Pacific Ocean to 26th Street. At the same time, an evacuation warning was issued for the area between San Vicente Boulevard and Montana Avenue, from 11th Street to 26th Street, and for the area between San Vicente Boulevard and Montana Avenue, between PCH and 11th Street (see Table 10-2). The areas under evacuation orders and evacuation warnings were expanded on January 8th after several homes on Chautauqua Boulevard, in Pacific Palisades and 0.4 miles north of Santa Monica city limits, ignited and were ultimately destroyed. Specifically, on January 8th, the evacuation orders were expanded to include the area between San Vicente Boulevard and Montana Avenue from 11th Street to PCH, while an evacuation warning was issued for the area between Montana Avenue and Wilshire Boulevard, from 10th Street to PCH. As the days progressed, some of the areas under evacuation orders were downgraded to evacuation warnings. The last evacuation warnings were cancelled on January 18th at 12:00 PM.

Table 10-2: Zones in Santa Monica Under Evacuation Orders and Evacuation Warnings During the Palisades Fires of January 2025
Geographic Area
Dates and Times*
When Evacuation Orders
Were In Effect
Dates and Times*
When Evacuation
Warnings Were In Effect
From San Vicente Blvd north to the City limits,
from the Pacific Ocean to 26th St
01/07/2025, 19:24 to
01/13/2025, 8:00
01/13/2025, 8:00 to
01/18/2025, 12:00
Between San Vicente Blvd and Montana Ave,
from PCH to 11th St
01/082025, 14:30 to
01/10/2025, 15:22
01/07/2025, 19:24 to
01/08/2025, 14:30 and
01/10/2025, 15:22 to
01/13/2025, 08:00
Between San Vicente Blvd and Montana Ave,
from 11th St to 26th St NA 01/07/2025, 19:24 to 01/13/2025, 0:800 Between Montana Ave and Wilshire Blvd,
from PCH to 10th St NA 01/08/2025, 14:30 to 01/10/2025, 15:22 *Times are based on a 24-hour clock.

Evacuation decisions were directed by the Santa Monica Police Department (SMPD) in close coordination with the Santa Monica EOC, the CAL FIRE Incident Management Team 2, and the Los Angeles County EOC. SMPD was primarily responsible for the evacuation orders with door-to-door notifications to residences and businesses, and implementing traffic closure points to prohibit reentry. The City’s Department of Transportation deployed buses and bus operators to evacuees in need of transportation from the evacuation zones to the American Red Cross emergency shelter. At the start of the fire, the SMPD also implemented traffic closure procedures to facilitate evacuation traffic from Malibu and Pacific Palisades through Santa Monica, and prevent evacuation traffic bottlenecks. The SMPD also redirected traffic from the westbound I-10 Freeway into Santa Monica thereby prohibiting access into the burn zone from PCH, and closed several streets to prevent access into the Los Angeles burn zone from various coastal and northern access roads. On January 8th, Santa Monica officials issued a curfew order for all evacuation areas in the city, to prevent looting of evacuated Santa Monica properties and mitigate security concerns in Pacific Palisades and Malibu.

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Eaton Fire of 2025
The Eaton fire began in the early evening of January 7, 2025, the same day as the Palisades fire. The fire was first reported on a hillside above and to the east of Eaton Canyon Wash, across the wash from the intersection of Altadena Drive and Canyon Close Road in northeastern Pasadena, near high-tension power lines. Strong Santa Ana winds were blowing in the region, and the fire spread very quickly to the south-southwest, such that within 10 minutes of having started, the fire had spread 10 acres, and less than 10 minutes later, flying embers were setting on fire structures that were nearly 1 mile away. Night-flying helicopters from the Los Angeles County Fire Department were on the scene less than 20 minutes after the fire was first reported, but, given the strong winds, were not able to drop water on the blaze. Two of the helicopters had to leave the area while a third managed to stay in the vicinity and conveyed information on the fire spread to ground crews.43F 44 The fire grew overnight; a little past midnight the fire had expanded to more than 1,000 acres, and by early morning on January 8th, it had grown to more than 2,200 acres. Between 6:30 and 10:30 AM on the 8th, it grew to more than 10,600 acres with zero containment. Over the next few days the fire continued to grow, albeit at a slower rate, and firefighters started to make inroads. On January 12th the fire was 27% contained, on the 16th it was 55% contained, and on the 18th it was 73% contained. Full containment was reported on January 31st .44F
45 Ultimately, the Eaton fire burned an estimated 14,021 acres, decimating the community of Altadena, and damaging portions of the cities of Pasadena and Sierra Madre. With 9,414 structures destroyed and 1,074 structures damaged, the Eaton fire is now considered the second-most destructive, and fifth deadliest historical fire in California (see Table 10-1). On April 3rd, the Los Angeles County Office of the Medical Examiner reported that remains found in Altadena were human, bringing the death toll from the Eaton fire to 18. As of the writing of this report, the cause of the fire is still under investigation, with reports from residents near where the fire started suggesting that the fire was caused by faulty power lines owned by Southern California Edison that were not de-energized in response to the red flag warnings that had been issued for the region by the National Weather Service.

Wildfire Characteristics
The wildland fire hazard of an area is typically based on the combined input of several parameters.

These conditions are briefly described below:
• Fuel loading: i.e., the density and type of vegetation, with native chaparral vegetation; thicket stands that have not been cleared or have not burned in decades; and dry, flammable vegetation surrounding structures all posing a high fire hazard. In the WUI, fuel includes not only natural vegetation, but irrigated or cultivated vegetation in parks and landscaped areas, structures (such as homes and commercial structures), infrastructure (bridges, utilities), and other features (such as fences, decks, propane tanks, etc.).45F 46 • Topography: i.e., slope, which influences the movement of air and thus the fire direction, with steeper slopes having a higher rate of wildfire spread.

44 https://en.wikipedia.org/wiki/Eaton_Fire, accessed April 25- May 6, 2025. 45 Ibid. 46 https://lci.ca.gov/docs/20220817-Complete_WUI_Planning_Guide.pdf, accessed May 5-6, 2025.

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• Weather: the southern California Mediterranean climate, with less than 30 inches of yearly precipitation; hot dry summers; and high, hot, dry winds in the fall, create a high fire risk. • Drought conditions: periods of unusual low precipitation may result in large geographic areas with abundant dry or dead vegetation that is more likely to burn, and reduced storage in water reservoirs may limit the availability of water to fight fires. • Dwelling density and development: Isolated structures built at the end of narrow roads, surrounded by vegetation, are difficult to evacuate and protect during a wildland fire.

Similarly, densely packed structures, especially if surrounded by dense vegetation and above-ground power lines, may spread a wildfire and hinder firefighting efforts. • Wildfire history: As indicated by the data on Figure 10-1, areas that have burned in the past have a higher probability of burning again. Areas with thick underbrush that has not burned in a long time have a higher fire hazard.
• Existing mitigation measures: local mitigation measures in place (such as an extensive network of fire hydrants, fire-rated46F
47 construction, fuel modification zones, etc.) can help reduce the fire rating of an area.

There are three categories of interface fire: The classic WUI occurs where well-defined urban and suburban development presses up against open expanses of wildland areas; the mixed WUI characterized by isolated homes, subdivisions and small communities situated predominantly in wildland settings; and the occluded WUI where islands of wildland vegetation occur inside a largely urbanized area.

As described in the historical fires section above, certain conditions are often present when significant WUI fires have occurred. The most common conditions include: hot, dry and windy weather; a large fuel load (dense stands of dry vegetation); steep terrain with limited or no vehicular access; lack or limited water to fight the fire; communication issues that hinder evacuation efforts and/or cooperation efforts between responding units; or multiple fires at the same time that overwhelm the available firefighting resources. Once a fire has started, several conditions influence its behavior, including fuel, topography, weather, and degree of development (dwelling density and accessibility), building construction (with emphasis on the use of fire-retardant construction materials and combustible roofs), and the availability of local mitigation measures and resources (such as nearby fire stations, fire hydrants, roads, fuel modification zones, fire sprinklers in structures, etc.). The most significant of these conditions are discussed further below. • The Interface: A challenge southern California faces regarding its wildfire hazard is the result of the increasing number of houses being built at the WUI. Every year the growing population has expanded farther and farther into the hills and mountains, including forest lands. The increased number of structures at the interface means an increase in threats to life and property from fires, often pushing existing fire protection systems beyond original or current design and capability. Property owners in the interface are often not aware of the threats they face, nor their responsibilities in managing this hazard. Therefore, many owners do little

47 Fire-rated construction materials or assemblies have been specifically designed and tested to withstand fire for a given period of time, usually measured in minutes or hours. The rating indicates how long the material can maintain its structural integrity when exposed to fire, heat and smoke.

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to manage or offset the fire hazards on their own properties. Furthermore, human activities increase the incidence of fire ignition and potential damage. • Fuel: Fuel is the material that feeds a fire and is a key factor in wildfire behavior. Fuel is classified by volume and by type. Volume is described in terms of "fuel loading," or the amount of available vegetative fuel. The type of fuel also influences wildfire. Southern California has two distinct areas of risk for wildland fire: 1) The foothills and lower mountain areas most often covered with scrub brush or chaparral, and 2) the forested terrain at higher elevations, in the mountains.

Chaparral is a primary fuel of southern California wildfires. In southern California, chaparral habitat ranges in elevation from near sea level to over 5,000 feet. Chaparral communities experience long dry summers and receive most of their annual precipitation from winter rains. Some chaparral communities have evolved so that they require fire to spawn regeneration. Many species invite fire through the production of plant materials with large surface-to-volume ratios, volatile oils and periodic die-back of vegetation. These species have further adapted to display special reproductive mechanisms following fire. For example, several species produce vast quantities of seeds which lie dormant until fire triggers germination. The parent plant which produces these seeds defends itself from fire with a thick layer of bark that allows enough of the plant to survive so that the plant can crown sprout following the blaze. In general, chaparral community plants have adapted to fire through the following methods: a) fire induced flowering, b) bud production and sprouting subsequent to fire, c) in-soil seed storage and fire-stimulated germination, and d) on-plant seed storage and fire-stimulated dispersal.

Forest fires pose a higher risk to the WUI, as exemplified by the 2003 fires in San Bernardino and San Diego counties. The magnitude of those fires was the result of three primary factors:
1) severe drought, locally accompanied by a series of storms that produced thousands of lightning strikes and windy conditions; 2) an infestation of bark beetles that had killed thousands of mature trees in the region; and 3) the effects of wildfire suppression over the previous century that had led to buildup of brush and small-diameter trees in the forests.

This last factor is discussed further below.

Modern forests are generally significantly denser than they were in past centuries, especially prior to the arrival of European settlers. Thus, Lewis and Clark, on their exploration of the American Northwest in the early 1800s, reported that forests were relatively open, with an estimated 20 to 25 mature trees per acre. Forest density was likely controlled by lightningstarted fires that would sweep through, clearing out the underbrush and small trees, in addition to brush clearing conducted by Indigenous people to manage their surroundings and promote hunting, the production of food, reduce pests, support ceremonial practices, and other similar purposes.47F
48 Today’s forests typically have 300 to 400 mature trees to an acre, along with thick underbrush.48F
49 This density makes trees susceptible to disease, and less

48 Knight, C.A., Anderson, L., Bunting, M.J., Champagne, M., Clayburn, R.M., Crawford, J.N., KlimaszewskiPatterson, A., Knapp, E.E., Lake, F.K., Mensing, S.A., Wahl, D., Wanket, J., Watts-Tobin, A., Potts, M.D. and Battles, J.J., 2022, Land management explains major trends in forest structure and composition over the last millennium in California’s Klamath Mountains: Proceedings of the National Academy of Sciences (PNAS), Vol. 119, No. 2, e2116264119, doi:10.1073/pnas.2116264119. 49 According to Yablonski, B., 2022, The Big Burn of 1910 and the choking of America’s forests: Decades of fire suppression fuel catastrophic fires today: PERC Reports, Vol. 41, No. 1 (available at https://www.perc.org/wpcontent/uploads/2023/04/PR-SUM22-220608-WEB-spreads-1.pdf), in California, prior to White settlement, most forest types had about 64 trees per acre, whereas today most forests have about 300 trees per acre.

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drought- and fire-resistant. The thick under-story causes forest fires to burn intensely, which destroys the mature trees, so that damaged forests take decades to recover, rather than a few years. Unfortunately, this change is the result of the well-intentioned but misguided forest management programs that began in the early 1900s, in part as a result of the Big Burn of 1910, a devastating forest fire that burned about three million acres in western Montana and northern Idaho.49F
50 Essentially, these programs required that forest fires be avoided at all costs, with the use of prescribed fires and cultural burning prohibited, and policy requiring that all forest fires be suppressed as soon as possible, usually by 10 AM the day after the fire was first reported.50F
51 After nearly a century of these fire suppression efforts, “dog-hair" thickets have accumulated, which enable high intensity fires to flare and spread rapidly. • Topography: Topography influences the movement of air, thereby directing a fire course.

For example, if the percentage of uphill slope doubles, the rate of spread in wildfire will likely double. Gulches and canyons can funnel air and act as chimneys, which intensify fire behavior and cause the fire to spread faster. Solar heating of dry, south-facing slopes produces up-slope drafts that can complicate fire behavior. Unfortunately, hillsides with hazardous topographic characteristics are also desirable residential areas in many communities. This underscores the need for wildfire hazard mitigation and increased education and outreach to homeowners living in interface areas. • Weather: Weather patterns combined with certain geographic locations can create a favorable climate for wildfire activity. Areas where annual precipitation is less than 30 inches per year, such as southern California, are extremely fire susceptible. High-risk areas in southern California share a hot, dry season in late summer and early fall when high temperatures and low humidity favor fire activity. Santa Ana winds, which are heated by compression as they flow southwestward from Utah to southern California (see Section 11), create a particularly high risk, as they can rapidly spread what might otherwise be a small fire.

Recent concerns about the effects of climate change, particularly drought, are contributing to concerns about wildfire vulnerability. The term drought is applied to a period in which an unusual scarcity of rain causes a serious hydrological imbalance. Unusually dry winters, or significantly less rainfall than normal, can lead to relatively drier conditions and leave reservoirs and water tables lower. Drought leads to problems with irrigation and may contribute to additional fires, or additional difficulties in fighting fires. This is covered in greater detail in Section 11.

The Santa Monica Mountains area typically has mild, wet winters that lead to an annual growth of grasses and plants. This vegetation dries out during the hot summer months and is exposed to Santa Ana wind conditions in the fall. During Santa Ana conditions, winds in excess of 40 miles per hour (mph) are typical; gusts in excess of 100 mph may occur locally.

Santa Ana winds are generally consistent in their direction, but when combined with winds generated from burning vegetation, the wind direction generally becomes extremely erratic.

This can stress firefighting resources and reduce firefighting success. • Urban Development: As mentioned previously, growth and development in scrubland and forested areas is increasing the number of human-made structures in the interface areas of

50 Ibid. 51 https://wildfiretaskforce.org/wp-content/uploads/2022/05/californias-strategic-plan-for-expanding-the-use-ofbeneficial-fire.pdf, accessed May 12, 2025.

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southern California. Wildfire has an effect on development, yet development can also influence wildfire. The newer, larger homes being built in the WUI, with large exterior surface areas, provide more opportunities for embers and flames to ignite the structure, whereas the surrounding large lots are potentially more challenging to maintain as adequate defensible space. Owners often prefer homes that are private, have scenic views, are nestled in vegetation and use “natural” construction materials. A private setting may be far from public roads, or hidden behind a narrow, curving driveway. These conditions, however, make evacuation and firefighting difficult. The scenic views found along mountain ridges can also mean areas of dangerous topography. Natural vegetation contributes to scenic beauty, but it may also provide a ready trail of fuel leading a fire directly to the combustible fuels of the home itself.

Wildfire Hazard Identification
In California, wildfire hazard mapping, wildfire protection, and wildfire suppression are managed and conducted by three separate fire authorities in regions referred to as Federal, State and Local Responsibility Areas.51F
52 Each one of these is described further below.

The Federal and State governments have each developed their own methodologies to quantify the severity of the fire hazard in a region. These methodologies were generally developed in response to specific fires that caused significant loss of life and/or property damage. Early methods characterized the fire hazard of a region based on a weighted factor that typically considered fuel, weather and topography. More recent systems rely on the use of Geographic Information System (GIS) technology to integrate these factors to map the hazards, predict fire behavior and evaluate the impact that wildland fire would have on the surrounding communities and watersheds. Ranges of the wildfire hazard are further determined by the ease of fire ignition due to natural or human conditions and the difficulty of fire suppression. The wildfire hazard is also magnified by several factors related to fire suppression/control such as the surrounding fuel load, weather, topography and property characteristics.

Federal Responsibility Areas (FRAs)
Federal Responsibility Areas (FRAs) are lands in California that are typically owned or controlled by federal agencies where the US Forest Service, with no oversight from the State, manages all fire suppression and protection. These lands include, but are not limited to those controlled by the Bureau of Land Management (BLM), the Forest Service, and the National Park Service. Although the Federal government is responsible for these lands, given that Federal and State lands often adjoin each other, FRAs are often managed through cooperative agreements between Federal and State agencies in an effort to provide effective fire suppression and protection to both Federal and State lands.

Technical, financial, and resource guidance in support of wildland fire management across Federal lands in the United States is provided by the National Fire Plan (NFP). The NFP was authorized by the U.S. Congress in the year 2000 in response to the wildfires of that year. The NFP is a cooperative effort of the US Department of Agriculture’s Forest Service, the Department of the Interior, and the

52 Miller, R.K., Field, C.B., and Mach, K.J., 2020, Factors influencing adoption and rejection of fire hazard severity zone maps in California: International Journal of Disaster Risk Reduction, Vol. 50, doi:10.1016/j.ijdrr.2020.101686.

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National Association of State Foresters, and addresses firefighting, rehabilitation, hazardous fuel reduction, community assistance, and accountability.52F 53 Consistent with those objectives, the NFP emphasizes steps necessary to: 1) assure that firefighting resources and personnel are available to respond to wildfires that threaten lives and property; 2) reduce hazardous fuels as a means to decrease the likelihood of large, damaging fires occurring, especially near the WUI, 3) conduct emergency stabilization and rehabilitation of landscapes and communities impacted by a wildfire, and 4) actively participate in the intergovernmental Wildland Fire Leadership Council, a committee dedicated to the consistent implementation of wildland fire policies, goals, and management activities.53F
54 The NFP encourages the use of hazardous fuel
reduction treatment techniques (including prescribed fire alone, mechanical treatment alone, mechanical treatment plus prescribed fire, and other/wildland fire use, such as allowing lightningcaused fires to burn) to reduce the impact of wildland fire in FRAs and FRA-adjacent communities within the WUI. Another Federal wildland fire initiative that helps to reduce the risk posed by wildfires is the Healthy Forests Initiative (HFI) which, supported by several administrative reforms enacted in 2002 and 2003, allow Federal agencies to streamline the process of conducting fuel reduction activities in FRAs.

State Responsibility Areas (SRAs)
State Responsibility Areas (SRAs) include State lands, unincorporated communities and private property covered wholly or in part by timber, brush, undergrowth or grass. Wildfire hazard management of these lands is accomplished through laws and requirements enacted by the State through the California Government Code, with CAL FIRE being the agency responsible for firefighting in SRAs.

Legislative mandates passed in 1981 (Senate Bill 81, Ayala, 1981) and 1982 (Senate Bill 1916, Ayala, 1982; codified in Public Resources Code 4201-4204), that became effective on July 1, 1986, first required the State Fire Marshall to develop and implement a system to classify lands within SRAs according to their fire hazards into Fire Hazard Severity Zones (FHSZs). This program was developed in response to the Panorama fire in San Bernardino County in 1980. Areas are rated as having a moderate, high or very high fire severity based primarily on fuel types, their probability of burning and expected fire behavior. Specifically, areas are assigned a hazard score that considers fire history, vegetation, predicted flame length, ember production and movement, topography (terrain) and typical fire weather. These ratings do not take into consideration mitigation measures that may have been implemented, such as fire retardant construction or fuel reduction efforts, and the ranking categories are not an estimate of structural loss or potential risk.

The State mandates wildfire-resistant standards in fire-hazard zoned areas, including a defensible space buffer, fire-resistant materials for all new construction and major retrofits in accordance with Chapter 7A of the California Government Code, and access restriction if a disaster is ongoing. Local jurisdictions may impose more stringent requirements. 54F 55 Mandatory and recommended mitigation
strategies that can be implemented by property owners to reduce their wildfire hazard are discussed in more detail later in this section.

53 https://www.forestsandrangelands.gov/resources/overview/, accessed May 13, 2025. 54 Ibid, and https://www.forestsandrangelands.gov/leadership, both accessed May 13, 2025. 55 https://readyforwildfire.org/fire-safety-laws/, accessed May 9, 2025.

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Local Responsibility Areas (LRAs)
Local Responsibility Areas (LRAs) are incorporated communities where local governments oversee fire protection. In LRAs, City governments establish or adopt local ordinances, often modeled after the California Building and Fire Codes, and enforce land use planning, zoning and building permits designed to reduce the wildfire hazard in their jurisdiction.

The identification of areas or properties within LRAs at high risk of being impacted by a wildfire was first mandated by the Bates Bill (Assembly Bill 337, September 29, 1992). This legislation was a direct result of the great loss of lives and homes in the Oakland Hills Tunnel Fire of 1991 (see Table 10-1). Briefly, CAL FIRE in cooperation with local fire authorities was tasked to identify Very High Fire Hazard Severity Zones (VHFHSZs) in Local Responsibility Areas (LRAs). To accomplish this, CAL FIRE formed a working group comprised of state and local representatives that devised a point system that considers fuel (vegetation), slope, weather, and dwelling density. To qualify as a VHFHSZ, an area has to score ten or more points in the grading scale.

Once the boundaries of a VHFHSZ have been delineated, CAL FIRE notifies the local fire authorities that are responsible for fire prevention and suppression within that area. Local agencies must adopt at a minimum the maps as identified by the State Fire Marshal. California Fire Code (CFC) 4904.3.2 allows the local agency to have discretion to expand those areas, but local fire authorities cannot reduce or remove the VHFHSZs identified and designated as such by the State. This means that a local agency may include other areas in their jurisdiction not identified by the State as VHFHSZs into their local maps, provided that they have substantial evidence to support their findings.

Properties within VHFHSZs are required to comply with a variety of building requirements and vegetation management practices spelled out in the California Fire Code.

Mapped Wildfire Hazard Zones Near and In Santa Monica
There are no Federal Responsibility and State Responsibility Areas (FRAs and SRAs) near Santa Monica. The closest SRA to Santa Monica is in the Santa Monica Mountains area north of Malibu, stretching west from Tuna Canyon Park to Point Mugu State Park, and including a large portion of the Santa Monica Mountains National Recreation Area. Within the larger SRA there are several pockets and larger areas that are managed by the Federal government and are thus FRAs. The SRAs and FRAs closest to Santa Monica as of December 2024 are shown on Figure 10-3.

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Figure 10-3: Federal Responsibility Areas (FRAs) in light green and State Responsibility Areas (SRAs) in yellow to the north and northwest of Santa Monica as of December 31, 2024 (note that these areas continue to the north and west, outside of the boundaries of this figure; City of Santa Monica boundaries, in turquoise, are approximate) Source: Modified from
https://experience.arcgis.com/experience/bd8234bfe71548b087b11210a0d7d45e?id=468717e399fa4238ad 86861638765ce1, accessed May 9, 2025.

Most of Santa Monica has relatively gentle topography and is highly urbanized. Moreover, Santa Monica does not press against open wildland areas in the southern flanks of the Santa Monica Mountains, and the vegetated areas within the city are for the most part landscaped and irrigated, although the 2025 Palisades and Eaton fires showed that urban landscapes can burn and transmit fire. There are at least three canyons in the southern flanks of the Santa Monica Mountains that could convey a wildfire to the northern city boundaries. These are the Mandeville, Sullivan and Rustic canyons. Wildfires in Mandeville and Sullivan canyons could burn down to Santa Monica Canyon, along the northern city boundary. Although less likely given their extensive development, there are other canyons farther to the northeast of the city that if ignited, could convey a WUI fire to the northeastern portion of Santa Monica in the area of the Brentwood Country Club, and then onto the vegetated corridor that extends from Montana Avenue to Centinela Avenue.

Although these areas have not burned historically, there is a small but significant possibility that these areas could burn in the future, a condition that has recently been recognized by CAL FIRE (see below). Thus, enhanced onsite protection for structures and people in or adjacent to these areas is recommended, including educating property owners about their responsibility in maintaining their properties and adhering to construction standards that make their houses more fire-resistant. The bluffs of Pacific Palisades are also locally covered with vegetation that could be ignited by embers blown in from the north-northeast, or as a result of human activities, such as illegal encampments by unhoused individuals (small vegetation fires have occurred here before).

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Prior to 2025, the city of Santa Monica was not identified as having a wildfire hazard, with the nearest VHFHSZ bordering the city on its northern side. Following the January 2025 Palisades fire, CAL FIRE has issued a new map that places the northern portion of Santa Monica within a VHFHSZ.

Narrow strips to the south of the VHFHSZ are also now considered as having a high and moderate fire hazard. The City of Santa Monica Fire Department has recommended that City Council adopt this new fire hazard map issued by the State with no changes. The newly issued fire hazard zones are shown on Figure 10-4 (also included as Plate H-17 in Appendix H). Fire hazard mitigations that are now required in these areas are discussed further in the following sections of this report.

As briefly mentioned before, climate change is expected to increase the likelihood of wildland fires in the mountains and hills surrounding the Los Angeles basin. A study conducted in the Santa Monica Mountains National Recreation Area found that in 2020, invasive, non-native, highly flammable annual grasses and herbaceous plants amounted to 34% of the vegetation cover in the area (Stork et al., 2023). This is significant because in the Santa Monica Mountains, this type of vegetation directly correlates with higher property losses based on analysis of wildland fires that occurred there between 2001 and 2010 (Syphard et al., 2012). Furthermore, simulations conducted by Dong et al. (2022) suggest that the number of annual large fire days in southern California will increase from about 36 days in 1970-1999 to about 58 days under the moderate RCP 4.5 scenario, and about 71 days under the RCP 8.5 scenario55F

56. These numbers, the authors indicate, reflect “both
an intensification of conditions during the traditional summer fire season and a lengthening of the large fire season in spring and fall.”
Overall, burned areas in southern California are projected to increase over 60% for Santa-Ana-wind based fires and over 75% for non-Santa Ana-wind fires (Hall et al., 2018). In Los Angeles County, the San Gabriel Mountains have the highest degree of wildfire risk and are projected to experience an increase in wildfire burn area of approximately 40% and 50% in 2050 and 2080, respectively, under the RCP 8.5 scenario. In the watershed immediately to the north and northwest of Santa Monica, which is defined by the western half of the south-facing slopes of the Santa Monica Mountains, these numbers are approximately 19% and 11% respectively, compared to the 1961- 1990 baseline period.

56 Representative Concentration Pathway (RCP) 4.5 and RCP 8.5 are two of the four scenarios used by the Intergovernmental Panel on Climate Change to model future climate change based on different greenhouse gas emission trajectories. RCP 4.5 is an intermediate scenario, and RCP 8.5 is a business-as-usual, worst-case scenario. For additional information, refer to Section 11.

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STRUCTURE FIRES
Definition and Recent Statistics
Structure fires are fires that affect the structural components of a building or structure, including residential, commercial, and industrial buildings, and infrastructure such as bridges. A structure fire can be confined to a single room, a portion of a building, or can engulf the entire structure, and can involve any and all parts of a structure, such as the walls, roof, or floors.

A 2021 report by FEMA56F
57 that evaluated the incidence of building fires in the United States indicated that an estimated 368,500 residential57F
58 building fires occurred in the country from 2017 to 2019, with these fires accounting for an estimated 2,770 deaths, 11,650 injuries, and property losses of about $8.1 billion. Another similar analysis of fires in the United States (Hall, 2024)58F 59 found that an
estimated 470,000 fires occurred throughout the country in 2023, resulting in 3,070 civilian deaths, 11,790 civilian injuries, and about $14.7 billion in property losses. Note that the statistics for 2023 alone are higher than those for 2017-2019 combined. Of the structure fires reported in 2023, about 352,000 were residential fires, accounting for nearly 75% of the total. Furthermore, residential structure fires in 2023 accounted for more than 95% of civilian deaths, more than 86% of civilian injuries, and more than 77% of property losses reported. The numbers provided are thought to underestimate the total number of fires that occurred in buildings given that many fires confined to their point of origin, such as a fire in a cooking pot or in an oven, go unreported.

Hall (2024)59F
60 also reviewed fire statistics in the United States for the years between 1980 and 2023 inclusive and found that the number of civilian deaths and injuries based on total population have decreased over the past 43 years. Specifically, in 1980, 28.6 civilians out of every 1 million died in structure fires compared to 11.0 civilians in 2023 (Figure 10-5[A]). Similarly, the number of fires per year accounting for the overall increase in population has also decreased from 13.1 total fires per 1,000 people in 1980 to 4.1 total fires per 1,000 people in 2023, and home fires have decreased from 3.2 per 1,000 people in 1980 to 1.0 in 2023 (Figure 10-5[B]).

However, when looking at the number of deaths per number of home fires reported, there actually has been an increase in deaths over the years, with 7.1 deaths reported for every 1,000 home fires reported in 1980 compared to 8.7 deaths for every 1,000 home fires reported in 2023 (see Figure 10-5[C]). It is noteworthy that the number of deaths associated with apartment fires has decreased over time, with this thought to be related to increased regulations and higher oversight by fire departments of multi-family residential structures (such as monitored fire detection systems in apartment complexes that lead to fire department response when a fire alarm is triggered). The cost of structure fires has also increased over the years, even when adjusted for inflation. Thus, the average loss per structure fire in 1980 was about $5,200 ($19,100 in 2023 dollars), whereas in 2023, the average loss per structure fire amounted to $31,200 (see Figure 10-5[D]; these figures exclude the Twin Tower losses on 9/11/2001). These figures show that although there have been

57 https://www.usfa.fema.gov/downloads/pdf/statistics/v21i2.pdf, accessed May 13, 2025 58 The term residential in the FEMA report includes single-family homes, two-family homes, multi-family buildings, manufactured housing, hotels, motels, dormitories, assisted living facilities and halfway houses. It does not include prisons, nursing homes, juvenile care facilities, or hospitals. 59 Hall, S., 2024, Fire loss in the United States: NFPA Research article available from https://www.nfpa.org/education-and-research/research/nfpa-research/fire-statistical-reports/fire-loss-in-the-unitedstates, accessed May 13-14, 2025. 60 Ibid.

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improvements in reducing the number and impacts of structure fires, these still pose a significant hazard and that more can be done to reduce the losses associated with structure fires.

Figure 10-5: Various Statistics for Fire Losses in the United States, 1980-2023 [A]: Civilian Fire Deaths Per Million Population [B]: Fires per 1,000 population by year [C]: Deaths per 1,000 Reported Home Fires by
Year and Occupancy [D]: Average loss per structure fire Source: Hall (2024)
Causes of Structure Fires
According to FEMA (2021)60F
61, cooking is the leading cause of residential building fires, accounting for more than 41% of all home fires. Although most cooking fires are small and confined to their point of origin, a still significant percentage of non-confined residential fires also start in cooking areas and kitchens. Table 10-3 lists the main causes of residential building fires in the U.S. for the period between 2017 and 2019. In residential buildings, the next most common areas where fires start are bedrooms (12%), family rooms or living rooms (6%), garages and carports (5%), vacant spaces and attics (5%), laundry areas (5%), and exterior wall surfaces (5%). Cooking is also the main cause of structure fires in non-residential buildings, such as assembly places, eating and drinking establishments, educational and institutional facilities, stores, offices, detached garages, industrial, manufacturing, and storage facilities.61F
62 In non-residential buildings, fires most often occur in kitchen areas, outside areas, storage buildings, and vehicle storage areas.62F 63 61 https://www.usfa.fema.gov/downloads/pdf/statistics/v21i2.pdf, accessed May 13-5, 2025 62 https://www.iccsafe.org/building-safety-journal/bsj-dives/non-residential-building-fires-report/, accessed May 15, 2025. 63
Ibid.

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In both residential and non-residential settings, the most significant factors contributing to ignition that lead to non-confined fires include the misuse of materials or products (such as combustible materials placed too close to a heat source; abandoned or discarded matches, cigarettes or other combustible materials), failure or malfunction of an electrical or mechanical system, operational deficiencies (such as unattended equipment), and inability to control the spread of what began as a small, confined fire. Characteristics common to the large, non-confined fires reported in the sources referred to for these statistics in both residential and non-residential structures is that a large percentage of the impacted buildings did not have fire alarms and were not fitted with automatic extinguishing systems.

Table 10-3: Causes of Residential Building Fires in the U.S. (2017-2019), Organized from Highest to Lowest Percentages
Cause Percentage Cause Percentage
Cooking 41.4 Unknown 18.5
Heating 7.6 Unintentional,
careless actions 6.1
Electrical malfunction 5.4 Intentional 3.5
Open flame 3.5 Other heat source 2.7
Appliances 2.4 Equipment missoperation, failure 1.9
Smoking 1.7 Exposure 1.5
Natural 1.4 Under investigation 1.1
Other equipment 1.0 Playing with heat
source

0.3 Factors that Impact Structure Fire Risk in a Community Fire departments quantify and classify structural fire risks to determine where a fire resulting in large losses of life or property is more likely to occur using criteria such as the following:
• Type of occupancy, that is residential, commercial, manufacturing, etc. • density, such as high-occupancy vs low-occupancy, and thus the risk and potential for loss of life presented by the occupancy type and occupancy load, including mobility of the occupants
• building size, height, including number of floors (stories) above ground level), and location • age of the building
• estimated dollar value or historical value of the occupancy • construction type and access
• unique hazards presented by the occupancy, such as the types of combustibles therein, hazardous materials, previous fire history
• needed fire flow versus available fire flow
• proximity to other buildings (called exposure separation), and • built-in protections, such as fire-resistant construction materials, built in fire alarms and fire protection systems such as fire sprinklers
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Occupancies that, given a combination of the characteristics listed above are recognized as likely to strain the fire department’s response capability, are called “target hazards.” Target hazards encompass all structural inventories in the community that have a maximum and significant fire risk, as described further below. Typically, fire departments identify the major target hazards in their service area and then perform intensive pre-fire planning, inspections and training to address the specific fire problems in that particular type of occupancy (for example, training to respond to fires in facilities that handle hazardous materials is significantly different than training to respond to a fire in a high-occupancy facility such as a mall, auditorium or night club).

Residential occupancy is typically, the most common target hazard due to the life-loss potential, 24- hour occupancy, and risk and frequency of events; however, the consequences of residential fires can be high or low, depending on the age of the structure, location, size, and occupancy load, among other factors. For example, in newer residential areas where construction includes fireresistant materials in addition to internal fire sprinkler and fire alarm systems, most building fires can be confined to the room or unit of origin, especially if the fire department responds promptly. In older residential areas where the building materials may not be fire-rated, there is a higher probability of a building fire spreading from the room of ignition to other rooms or units in the structure, and even spreading into adjacent structures, unless there is ample distance between structures, there are no strong winds, and the fire department is able to respond in a timely manner.

In medium- to high-density residential and commercial areas, narrow spaces in between structures may limit emergency access and/or evacuation of the structure during a fire. Access by emergency services personnel, including firefighters and medical response teams with gurneys, can be hindered if projections such as bay windows and roof awnings extend into the setback between structures, or if non-structural items, such as garbage cans or sheds are kept there. High-density occupancies may include multi-story buildings with multiple housing units or offices, enclosed shopping centers with large, open rooms that house highly flammable materials like clothing and paper goods (such as a large retail store at a mall), and large entertainment venues like movie theaters, night clubs and concert halls. High-density locales may also often be associated with heavy traffic conditions and limited parking areas for emergency response vehicles, both of which can impact response times.

Four classifications of risk are typically considered, as follows:
• High Probability/High Consequences (Maximum Risk) such as multi-family dwellings and residential buildings (especially older ones) that require a large amount of water and fire suppression personnel to contain the fire, have the potential for a high loss of life, are irreplaceable or would have a major financial or social impact on the community if lost, or have hazardous materials occupancies (see Section 12). Some of the high probability/high consequence targets that fire departments are most concerned about are high-rise buildings due to the specialized firefighting equipment needed, the limited routes of access into and out of a building, and the potential for great loss of life. • Low Probability/High Consequences (High Risk) are buildings of substantial size that have the potential for loss of life and property, and if lost to fire would have a significant impact on the community (in the form of reduced or eliminated critical services, lost jobs and/or tax revenue), but that have built-in fire protection systems and fire alarms. Examples include hospitals and medical facilities, schools, child-care centers and nursing homes, mid-size Local Hazard Mitigation Plan Section 10
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shopping malls, industrial occupancies that do not use or store hazardous materials, and large office complexes.
• High Probability/Low Consequences (Moderate Risk) are buildings of moderate size that can present a potential for loss of life and property, but that loss would be generally limited to the immediate occupants of the structure. Examples include smaller apartment buildings, small office buildings, older single-family residential homes built with non-fire rated construction materials and mobile homes.
• Low Probability/Low Consequences (Low Risk) are buildings that have limited exposure and are built of fire-retardant materials, include fire alarms and automatic fire suppression systems, and have a low potential of spreading to other structures. Fires in these structures have a high probability of being confined to the room of origin, and would pose a limited financial impact on the owners and the community. Examples include detached singlefamily dwellings and small structures not normally occupied by people.

Structure fire response requires numerous critical tasks to be performed simultaneously. The number of firefighters required to perform the tasks varies based upon the risk. Thus, the number of firefighters needed at a maximum or high-risk occupancy, such as a shopping mall or large industrial occupancy, would be significantly higher than for a fire in a lower-risk occupancy. Given the large number of firefighters that are required to respond to a high-risk, high-consequence fire, fire departments, such as the Santa Monica Fire Department, routinely rely on automatic and mutual aid agreements to address the fire-suppression needs of their community.

Fires After an Earthquake
Large fires following an earthquake in an urban region, although rare, have the potential to cause great losses. Two of the largest peace-time urban fires in history, the 1906 San Francisco, and 1923 Tokyo, Japan fires were caused by earthquakes. The conflagration in San Francisco after the 1906 earthquake was the single largest urban fire, and the single largest earthquake loss, in U.S. history.

Three days of fires consumed more than 28,000 buildings within a 4.6-square-mile area.63F 64 The cost
was (and is) staggering: $250 million in 1906 dollars, or about $8.7 billion in 2024 dollars.

More recently, the 1989 Loma Prieta earthquake, the 1994 Northridge earthquake, and the 1995 Kobe, Japan earthquake all demonstrate the current, real possibility of a fire-following-an earthquake developing into a conflagration. The Loma Prieta earthquake caused 41 fires64F 65, whereas the Kobe
earthquake is estimated to have caused 300 separate fires that damaged an area approximately equivalent to 70 U.S. city blocks65F
66 and contributed to more than 600 deaths. The moderately sized, M6.7 Northridge earthquake caused several structural fires, many the result of broken gas mains: the earthquake caused 15,021 natural gas leaks that resulted in three street fires, 51 structure fires (23 of these caused total ruin of the buildings) and the destruction by fire of 172 mobile homes. In one incident, the earthquake severed a 22-inch gas transmission line and a motorist ignited the gas while attempting to restart his stalled vehicle. Response to this fire was impeded by the earthquake’s rupture of a water main; five nearby homes were destroyed. Elsewhere, one mobile home fire started

64 Scawthorn, C., 1987, Fire Following Earthquake—Estimates of the Conflagration Risk to Insured Property in Greater Los Angeles and San Francisco: report prepared for the All-Industry Research Advisory Council, Oak Park, IL. Scawthorn, C., O’Rourke, T.D., and Blackburn, F.T., 2006, The 1906 San Francisco earthquake and fire—Enduring lessons for fire protection and water supply: Earthquake Spectra, Vol. 22, No. S2, pp. S135-S158. 65 https://www.iitk.ac.in/nicee/wcee/article/10_vol10_5983.pdf, accessed June 19, 2025. 66 https://www.nist.gov/el/earthquake-kobe-japan-1995, accessed June 19, 2025.

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when a downed power line ignited a ruptured transmission line. In many of the destroyed mobile homes, fires erupted when inadequate bracing allowed the homes to slip off their foundations, severing gas lines and igniting fires. There was a much greater incidence of mobile home fires (49.1 per thousand) than other structure fires (1.1 per thousand).

The damages from the 1994 earthquake echoed the findings of a study published in 1988 by the California Division of Mines and Geology (Toppozada and others, 198866F 67). The 1988 study
identified projected damages in the Los Angeles area as a result of an earthquake on the NewportInglewood fault. The earthquake scenario estimated that thousands of gas leaks would result from damage to pipelines, valves and service connections. That study prompted the Southern California Gas Company to start replacing their distribution pipelines with flexible plastic polyethylene pipe, and to develop ways to isolate and shut off sections of supply lines when breaks are severe.

Nevertheless, as a result of the 1994 Northridge earthquake, the Southern California Gas Company reported 35 breaks in its natural gas transmission lines and 717 breaks in distribution lines. About 74 percent of its 752 leaks were corrosion related. Furthermore, in the aftermath of the earthquake, 122,886 gas meters were closed by customers or emergency personnel. Thankfully, most of the leaks were small and could be repaired at the time of service restoration, but the costs and time associated with these repairs were considerable.

The major urban conflagrations in 1906 San Francisco and 1995 Kobe, Japan, among others, were in part the result of closely built, congested areas of attached buildings with no fire sprinklers, no adequate fire separations, no fire code enforcement, and narrow streets. In the past, fire apparatus and water supplies were also inadequate in many large cities, and many fire departments were comprised of volunteers. Many of these conditions no longer apply to the cities of today. However, the recent historical data show that fires after earthquakes continue to be a threat. Khorasani and Garlock (201767F
68) reported that at least 20 earthquakes between 1906 and 2014, including the earthquakes mentioned above, and ranging in size between magnitudes 5 and 9, resulted in firefollowing-earthquake losses. Scawthorn (198768F 69) and Cousins and Smith (200469F70) also found that
the number of ignitions increases with an increase in earthquake intensity.

Earthquake-induced fires have the potential to result in a worst-case fire-suppression scenario for a community as a result of a series of events that can combine to create what is referred to as a “cascade effect.” Specifically, damage to the electrical and gas systems can cause multiple, simultaneous fire ignitions distributed over a broad geographic area. Fallen electrical and gas appliances or equipment inside structures, especially if surrounded by flammable materials, can also start fires. Many of these interior fires may normally be put out quickly by the building occupants, but if the structure has been evacuated in response to the earthquake’s ground shaking, the fire may go unnoticed until it has spread to the point where a fire department response is necessary.

67 Toppozada, T.R., and others, 1988, Planning Scenario for a Major Earthquake on the Newport-Inglewood Fault (Los Angeles and Orange Counties): California Division of Mines and Geology Special Publication No. 99. 68 Khorasani, N.E. and Garlock, M.E.M., 2017, Overview of fire following earthquake: historical events and community responses: International Journal of Disaster Resilience in the Built Environment, Vol. 8, No. 2, pp. 158- 174; doi:10.1108/IJDRBE-02-2015-0005. 69 Scawthorn, C., 1987, Fire Following Earthquake—Estimates of the Conflagration Risk to Insured Property in Greater Los Angeles and San Francisco: report prepared for the All-Industry Research Advisory Council, Oak Park, IL. 70 Cousins, W.J., and Smith, W.D., 2004, Estimated losses due to post-earthquake fire in three New Zealand cities:

Proceedings of the Annual Technical Conference, 19-21 March 2004, Rotorua, New Zealand Society for Earthquake Engineering, Paper No. 028.

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Notification to the fire department of an ongoing structural fire may be delayed because of disruptions to the communications network, and if the firefighters are occupied in search and rescue operations, their ability to respond to these fires may be impaired or delayed due to limited resources and personnel. Damage to fire stations, and streets blocked by fallen debris or facades may also hinder the timely response by the fire department. Significantly, if the water distribution system has been damaged, reduced or non-existent water volume and pressure would further limit the fire suppression efforts (Juliá et al., 202170F
71). Finally, if earthquake-induced fires occur during Santa Ana wind conditions, the results can be far worse.

VULNERABILITY AND RISK ASSESSMENT
What is Susceptible to Wildfires in Santa Monica
Southern California neighborhoods at or near the WUI are characterized by a diverse mixture of housing structures, development patterns, ornamental and natural vegetation, and natural fuels. In the event of a wildfire, this diverse mixture of vegetation, structures and development patterns, compounded by the local topography and weather at that specific time, can result in an unwieldy and unpredictable fire. Factors important in fighting such fires include access, firebreaks, proximity of water sources, distance from a fire station, and available firefighting personnel and equipment. A review of past WUI fires has shown that many structures are destroyed or damaged for one or more of the following reasons:
• Combustible roofing material
• Wood construction
• Structures with no defensible space
• Fire department with poor access to structures
• Subdivisions located in heavy natural fuel types
• Structures located on steep slopes covered with flammable vegetation • Limited water supply and
• Winds over 30 miles per hour
As discussed previously, the northern portion of the city of Santa Monica is now considered to have a wildfire hazard, with the newly defined moderate, high, and very high fire hazard severity zones in the city shown on Figure 10-4 (and Plate H-17). These hazard zones were defined by CAL FIRE based on an analysis of factors such as:
• fire history (i.e., the recent, nearby Palisades fire that burned to within a few hundred feet of the northern city boundary),
• existing and future potential fuel conditions (such as densely vegetated slopes along Santa Monica canyon, the coastal bluffs and the I-10 embankments), • terrain and slope (houses on the north side of San Vicente Boulevard and streets north and west of San Vicente Boulevard that are at the top of the north-facing slope that forms the

71 Juliá, P.B., Ferreira, T.M., and Rodrigues, H., 2021, Post-earthquake fire risk assessment of historic urban areas: A scenario-based analysis applied to the Historic City Centre of Leiria, Portugal: International Journal of Disaster Risk Reduction, Vol. 60, doi:10.1016/j.ijdrr.2021.102287.

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south side of Santa Monica Canyon),
• structural density (i.e., distance between structures allowing fire to jump from one structure to another)
• fire occurrence and weather (i.e., hot, dry and windy conditions, and whether or not the area is experiencing a drought, with these conditions likely to become more common as a result of climate change), and
• possible ignition sources, including the possibility of Santa Ana winds transporting embers from adjacent burning areas to the northern portion of the city, and brushfires ignited within Santa Monica proper, along the coastal bluffs and other vegetated areas, that could then spread to developed areas.

It is important to note that the hazard zones mapped by CAL FIRE do not take into consideration mitigation measures that may be in place or could be implemented to reduce the hazard, including hardening of structures and fuel reduction efforts. The risk posed by a wildfire is the potential damage that a fire can do to the area based on factors such as those described above, taking into consideration the modifications that have been made, including the use of fire-resistant building materials and design, the implementation of fuel reduction projects, and the establishment of defensible spaces around existing structures.71F
72 Road access is a major issue for all emergency service providers. In many single-family residential neighborhoods, including several of the residential streets in Santa Monica, there is limited space for emergency vehicle turnarounds, hindering emergency workers’ access to the houses at risk. This is especially true in streets with parking lanes on both sides. Narrow winding roads with inadequate turn-around space are also particularly challenging as fire trucks are too long to maneuver in these roads. Fires at the WUI tend to move quickly, with most of the damage or losses generally occurring in the first few hours after the fire starts (refer to the descriptions of the 1978 Los Angeles and 2025 Eaton fires at the top of this section). Therefore, access to fire-impacted areas for the purposes of emergency response is critical. This requires streets that meet minimum access and egress requirements so that they can be traversed by fire apparatus.

As the 2025 Los Angeles area fires illustrated, the water supply system that feeds fire hydrants is not designed to fight a regional fire where multiple ignitions are being battled at the same time. Areas at higher elevations may be serviced by water that is pumped up to the higher elevations. In the event of a fire, and especially if the electric system has been powered down, it may be impossible to pump additional water to the reservoirs at or above the fire line. Emergency water storage is also critical, especially when battling large wildland fires. Leaks and breaks in the water distribution system, including leaking irrigation lines and open valves in destroyed homes72F 73, and residents using
firehoses to battle embers on their property, also reduced the amount of water available to the firefighters. A seven-day emergency storage supply in the reservoirs is recommended, especially in areas likely to be impacted by fires after earthquakes, due to the anticipated damage to the main water distribution system as a result of ground failure due to fault rupture, liquefaction, or landsliding.

A vulnerability assessment of the interface areas of the city at risk from wildfire requires knowledge about the population and total value of the property at risk, and an estimate of the area that would

72 https://osfm.fire.ca.gov/what-we-do/community-wildfire-preparedness-and-mitigation/fire-hazard-severity-zones, accessed May 13, 2025. 73 SMFD reported that this was a challenge during the 2025 Palisades fire.

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be impacted by the fire. Unlike an earthquake, which has the potential to impact the entire region, wildfires at the WUI are often contained thanks to the heroic efforts of the local fire department, generally with help from other local, regional, State, and Federal agencies. Thus, estimates of the potential loss are approximate at best. However, using the software Crisis Track and considering the areas in Santa Monica now identified as having a very high fire hazard, we estimate that property losses as a result of a wildfire just in that small northern portion of the city would range between $60 million and almost $600 million. A fire within the very high fire hazard zone would impact 1,715 structures. Given that nearly 99% of these structures are residential, a fire therein would result in the temporary or permanent displacement of thousands of residents.

Structure Fires
Recent historical records (for the years 2016 to 2019 inclusive) from the Santa Monica Fire Department show that fires comprise a small percentage (<2%) of the incidents that the Santa Monica Fire Department responds to on an annual basis, with structure fires accounting for about

0.53% of the total calls (Citygate Associates, 2020). For example, in 2019 alone, out of the 17,051 emergency calls that the fire department responded to, approximately 220 were for fires. Of these, 71 were reported as structure fires. All of these structure fires, except for five, occurred in the central portion of the city bounded by Montana Avenue on the north and Ocean Park Boulevard on the south. The five exceptions were structure fires reported in the southwestern portion of the city, south of Ocean Park Boulevard and generally west of Highland Avenue.73F 74 The fire occurrences in the city are generally reflective of the age of the structures in Santa Monica.

Most (85%) of the City’s housing stock was built more than 30 years ago, and thus built to older building standards and with non-fire resistive construction materials. Moreover, many buildings date from before the 1930s in the older sections of the city, including Ocean Park, the Third Street neighborhood, and the area between Montana Avenue on the north, Colorado Avenue on the south, the Pacific Ocean on the west and 26th Street on the east. Many of the oldest buildings in the city that predate the early 1930s are unreinforced masonry buildings that are susceptible to collapse during a fire, posing a significant risk to fire department responders. Even if retrofitted, the retrofits may not keep the structure from collapsing during a fire.

Single-family detached structures make up about 31% of the housing stock in Santa Monica; the remaining housing units include courtyard apartments, condominiums and large mixed-use residential complexes. Single-family units predominate in the northern and southern portions of the city, and multi-family units are concentrated along the central portion of the city.74F 75 Significantly, the
residential population density in the city ranges from about 1,500 people per square mile to more than 20,000 people per square mile, with an average of 11,067 people per square mile (based on 2022 Census data). This makes Santa Monica the 108-most densely populated incorporated area in the United States.75F
76 Moreover, some of the more densely populated areas have a high concentration of residents that are 65 years old and older. In addition to residential units, Santa Monica has approximately 4,325 other buildings used for commercial, industrial, education, religious and government purposes. These buildings house approximately 11,000 non-residential occupancies,

74 Citygate Associates, 2020, Community Risk Assessment / Standards of Cover Analysis, City of Santa Monica, CA, Volume 2 of 2: Map Atlas. 75 City of Santa Monica 2021-2029 Housing Element, Final Draft dated September 2022. 76 https://en.wikipedia.org/wiki/List_of_United_States_cities_by_population_density, accessed May 14, 2025.

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including offices, professional services, retailers, dining and entertainment-based businesses, healthcare facilities, schools, and government facilities.76F 77 The large commercial and
technological/industrial base in Santa Monica means that there is also a potential for chemical fires to occur in some areas of the city, which directly and indirectly can also impact nearby residential areas. The generation, use, or storage of chemicals at these facilities is conducted under the oversight of the local Certified Unified Program Agency (CUPA), who conducts compliance inspections on an annual basis to confirm that all of these substances are being handled appropriately. For more information on this refer to Section 12.

High Probability/High Consequences (Maximum Risk) target hazards in the city of Santa Monica include condominium and apartment buildings; large-occupancy buildings of historical significance like the Charmont Apartments, the Georgian Hotel, the Sovereign Hotel and the Hotel Casa del Mar; and large shopping centers and malls like the Santa Monica Place.

Low Probability/High Consequences (High Risk) buildings in Santa Monica include the two main hospitals (UCLA Santa Monica Medical Center and Providence Saint John’s Health Center), other medical facilities, schools, child-care centers and nursing homes, mid-size shopping malls, industrial occupancies that do not use or store hazardous materials, and large office complexes. The City’s Standards of Cover Study prepared by Citygate Associates (2020) identified 2,150 buildings in Santa Monica with a maximum or high fire risk.

High Probability/Low Consequences (Moderate Risk) buildings in Santa Monica include smaller apartment buildings, small office buildings, older single-family residential homes built with non-fire rated construction materials and mobile homes.

Low Probability/Low Consequences (Low Risk) buildings in Santa Monica include detached singlefamily dwellings built to recent building and fire codes, and small structures not normally occupied by people.

Significantly, in Santa Monica these risk categories often co-exist in the same area. For example, residential buildings often adjoin and/or are intermixed with commercial buildings, such as the residences immediately north and south of the businesses along Montana Avenue and Wilshire Boulevard. There are also the mixed-use buildings that typically house commercial businesses at ground level, and have residential units in the floors above. While this type of development has several environmental and social advantages in that it may reduce dependency on automobiles which in turn reduces traffic and improves air quality, and promotes economic investment and a sense of community, there are specific fire hazards associated with this type of development that need to be considered. This is especially true if the businesses on the ground floor include restaurants, bakeries, or engage in other commercial activities that involve the use of stoves or ovens, or the storage of flammable materials. As a result of infill development in the city, multi-family structures often occur next to single-family detached residences.

Given that several risk categories occur within the same geographic area, it is appropriate for the Santa Monica Fire Department to have several fire stations spread out across the city, with Fire Stations 1, 2 and 3 located in and servicing some of the most densely populated areas that include

77 Citygate Associates, 2020, Community Risk Assessment / Standards of Cover Analysis, City of Santa Monica, CA, Volume 1 of 2: Technical Report.

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all of these fire risk categories (see Figures 3-1 and 10-4 for the location of the fire stations in the city). Citygate Associates (2020) determined that all planning areas in the city, except for planning zone 5, which covers the area around the airport, have a moderate building fire risk. Planning zone 5 is considered to have a low building fire risk.

The high value of real-estate in Santa Monica means that a structure fire in the city, even if the fire impacts only a portion of the building, has the potential to result in tens to hundreds of thousands of dollars in property damage. Structure fires also displace households, or, if in a commercial or industrial building, can result in business interruptions, and economic losses. Structure fires can impact insurance premiums and availability, and property tax revenue losses.

Fires After an Earthquake
As discussed in greater detail in Section 6 – Earthquakes, there are some sections of Santa Monica where, due to ground failure as a result of either fault rupture or liquefaction, breaks in the gas mains and the water distribution system could lead to a significant fire-after-earthquake situation.

Specifically, the Santa Monica fault is mapped as extending through the northern portions of the city, whereas liquefaction-susceptible areas have been mapped along the coastline and in the far east-central portion of the city near the Interstate 10 (I-10) freeway. Refer to Figures 6-13 and 6-14 (and Plates H-4 and H-5 in Appendix H) for information regarding those areas of the city susceptible to surface fault rupture and liquefaction, respectively. Surface rupture, with the resultant breakage of gas transmission and distribution pipelines, and water mains, is expected to occur if the Santa Monica fault ruptures, causing an earthquake centered in Santa Monica. Liquefaction could occur not only in response to an earthquake on the Santa Monica fault, but also in response to earthquakes on the Newport-Inglewood, Palos Verdes, or other nearby faults.

Loss-estimation scenarios were conducted for the city of Santa Monica using HAZUS. Specifics of this analysis are discussed in detail in Section 6 – Earthquakes. Three different fire-after-earthquake scenarios were considered for the city. The results of these loss estimations indicate that Santa Monica could experience between three (3) and five (5) ignitions immediately following an earthquake, with the San Andreas and Newport-Inglewood fault earthquake scenarios triggering three ignitions, and the Santa Monica fault earthquake scenario triggering five ignitions (see Table 10-4). The burnt area resulting from these ignitions will vary depending on wind conditions.

The models estimated that between 0.12 and 0.35 percent of the total area covered by the city (equivalent to between 0.01 and 0.03 square miles) would be burnt by the fires following the earthquake. If Santa Ana wind conditions are present at the time of the earthquake, the burnt areas can be expected to be significantly larger.

The fires triggered by an earthquake on the San Andreas and Newport-Inglewood faults are anticipated to displace approximately 78 to 80 people, whereas the fires resulting from an earthquake on the Santa Monica fault are expected to displace about 407 people. Property losses as a result of these fires are estimated to range between about $20 million and $80 million. These values are for low wind conditions. If winds stronger than 30 miles per hour are blowing through the region at the time of the earthquake, the burnt area, number of people displaced, and property losses would be higher than those shown on Table 10-4. The significant loss that could be caused by earthquake-induced structure fires stress the importance for local firefighting resources to prioritize target hazard surveys post-earthquake to promptly identify and extinguish structure fires.

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Table 10-4: Fires Following an Earthquake
Earthquake Scenario No. of
Ignitions
Approximate
Burn Area
(% of city)
No. of
Displaced
Individuals
Building Value
Destroyed
(Millions of $)
Santa Monica 5 0.35 407 80
Newport-Inglewood 3 0.12 80 21
San Andreas 3 0.12 78 20
Social Vulnerability to Fires
Humans exposed to fire are at risk of injury, in the form of life-threatening burns, or death, and, as discussed above, fires can result in the destruction of property and infrastructure, which can lead to the displacement of people and even entire communities. Social vulnerability to fire refers to the susceptibility of individuals and communities to experience adverse impacts as a result of a fire. The factors that influence how an individual, family, and/or community prepare for, respond to, and recover from a fire include socioeconomic, demographic and infrastructural elements. Infrastructural factors are aspects of the built environment, such as the proximity of buildings and infrastructure to the WUI, the condition of the electrical infrastructure (such as above ground electric lines susceptible to strong wind events that can cause the lines to spark or fall, causing a fire), and the availability of adequate access roads and water supply to fight a fire.

Given that wildland fires do not recognize jurisdictional boundaries, can occur in areas vegetated with light fuels such as grasses and ornamental plants, and generally spread uphill, it is appropriate to consider the possibility that a wildland fire approaching Santa Monica from the north could extend into the residential areas facing Santa Monica Canyon, in the now identified VHFHSZ shown on Figure 10-4. These conditions, combined with strong winds from the north (prevalent in the Santa Monica region between October and February), could help transport embers from the fire front into other parts of the city. Although less likely, if a vegetation fire occurred in one of the City parks or the I-10 Freeway embankments, typically the result of homeless encampment activities, the fire could also spread to nearby structures.

The risk posed by a wildfire spreading into the northern or northeastern portion of the city, or a vegetation fire occurring in a city park and spreading to nearby areas was recognized in mapping by the Wildfire Risk to Communities website (https://wildfirerisk.org). This is a project of the U.S.

Department of Agriculture (USDA) Forest Service under the direction of Congress, and through a partnership with the Rocky Mountain Research Station’s Missoula Fire Sciences Laboratory, Pyrologix, and Headwaters Economics, a nonprofit research group, that helps communities understand their relative wildfire risk and socioeconomic vulnerability. Screen captures of Santa Monica’s relative wildfire risk, wildfire exposure, risk to houses, and impact to potentially vulnerable populations are presented on Figure 10-6. These findings as they pertain to the city of Santa Monica in comparison to the nation as a whole are discussed further below0F

78. 78 Based on data from wildfirerisk.org for Santa Monica, California accessed on May 19, 2025.

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The wildfire likelihood in Santa Monica, based on analyses by wildfirerisk.org, is now considered to be, on average, greater than 92% of the communities nationwide. Wildfire likelihood at the community level is the average annual probability of a wildfire occurring where housing units occur.

Similarly, homes in Santa Monica are considered to have, on average, a greater wildfire risk than 94% of the communities nationwide. This is a measure of the relative consequence of wildfire to residential structures everywhere on the landscape, whether a home actually exists there or not.

Wildfirerisk.org estimates that about 80 buildings in Santa Monica (amounting to less than 1% of the total building stock) are at direct exposure and may be ignited by adjacent vegetation, flying embers and nearby structures. An estimated additional 992 buildings (amounting to about 5% of the total buildings in the city) are in the indirect exposure zone and may be ignited by embers or hometo-home ignition. Thus, despite the relatively high wildfire likelihood north of Santa Monica (Figure 10-5), homes and other structures in Santa Monica have generally a low risk of being directly exposed to wildfires. This assessment is consistent with the findings of a 2023 study by Modaresi Rad et al.78F
79 that evaluated the social vulnerability of communities and people exposed to wildlife in the Western United States between 2000 and 2021. That study found that although the number of people in the West Coast exposed to wildfire has increased exponentially over the past decade, Californians exposed to wildfire generally have a low vulnerability because highly vulnerable people in the State more often live in large metropolitan areas that are not exposed to wildfire. Figure 10-5 shows that the wildfire likelihood, wildfire exposure and the wildfire risk to homes is not the same across Santa Monica, but rather concentrated along the northern and northeastern city boundaries.

The actual ability of a home to survive a fire is dependent on a variety of conditions including the home’s age, construction materials, whether or not the home is surrounded by flammable vegetation, and whether the home is owner- or non-owner occupied. More than 62% of the homes in Santa Monica were built before 1980, with a median year of structure build of 1966. This means that many of the homes in the city may not incorporate wildfire-resistant construction materials.

According to U.S. Census data79F
80, the owner-occupied housing unit rate in Santa Monica for the period between 2019 and 2023 is estimated at 28.8%, and data from the U.S. Department of Finance from 2023, as reported in the Santa Monica Daily Press80F 81, shows that an estimated 10% of the
housing stock in the city at that time was vacant.81F
82 A high percentage of non-owner-occupied
properties, seasonal homes and vacant homes may limit the scope of maintenance efforts, such as removal of dry flammable vegetation around the structure, that help reduce the home’s wildfire exposure. In addition, “the presence of many non-owner-occupied homes may also make it difficult for community leaders to reach homeowners whose support is needed for the passage of land use planning tools, such as landscape ordinances or building codes, that reduce the risk from wildfires.”82F
83 79 Modaresi Rad, A., Abatzoglou, J.T., Fleishman, E., Mockrin, M.H., Radeloff, V.C., Pourmohamad, Y., Cattau, M., Johnson, J.M., Higuera, P., Nauslar, N.J., Sadegh, M., 2023, Social vulnerability of the people exposed to wildfires in U.S. West Coast states: Science Advances, Vol. 9, No. 38, doi:10.1126/sciadv.adh4615. 80 https://www.census.gov/quickfacts/fact/table/santamonicacitycalifornia/BZA110222, accessed May 19, 2025. 81 https://smdp.com/news/population-decrease-and-housing-increase-drive-local-vacancy-rate-to-10percent/, accessed May 19, 2025 82 This number may be lower in 2025 in response to the Palisades fire, as the fire created a surge in demand for temporary housing, with displaced residents looking for alternative living arrangements. Specific statistics were not available. 83 Profile of Wildfire Risk report for Santa Monica, California downloaded from the wildfirerisk.org website on September 27, 2023.

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Wildfires, even if not occurring in the immediately adjacent region, can pose severe health hazards to sensitive populations. Thus, wildfires in the Santa Monica Mountains and surrounding areas, including the San Gabriel Mountains to the northeast, can indirectly expose Santa Monica residents and visitors to a variety of impacts. Specifically, smoke from wildfires can negatively impact local air quality, causing respiratory illnesses and eye inflammation. Smoke contains large amounts of air pollutants including volatile and semi-volatile organic materials and nitrogen oxides that form ozone and organic particulate matter (PM). For example, in November 2018, in response to the Camp Fire in Northern California, the daily air quality index (AQI) levels of PM smaller than 2.5 micrometers in diameter (PM 2.5) and ozone doubled to quadrupled across most of California. 83F 84 The smoke
produced by the Camp Fire also contained large concentrations of lead, zinc, and other metals.84F 85 Similarly, the 2025 Palisades and Eaton fires generated significant levels of air pollution across large portions of the Los Angeles basin.

Children, the elderly, and people with pre-existing conditions, such as asthma and heart conditions, are at higher risk from the impacts of smoke. Ash from wildfires may also include toxic, potentially carcinogenic substances. Inhaling these pollutants can cause respiratory, cardiovascular, and cerebrovascular issues ranging from asthma to heart disease, which disproportionally impact populations over 65 and those with underlying chronic illnesses, in addition to post-traumatic stress disorder and mental health issues. These impacts have also been shown to have long-term consequences, including shorter height in children born to mothers exposed to fire smoke, low birthweight and neurological issues in infants, and overall poorer health and early death for impacted adults85F
8686F87.

Several census tracts in Santa Monica have a significant percentage of populations that are disproportionally vulnerable to wildfire risk due to underlying health conditions, age, income levels, no access to a vehicle, and/or disabilities (see Figure 10-5; the blue-colored areas in the social vulnerability maps capture those census tracts where two, or all three, of the social vulnerability conditions highlighted prevail). Essentially, these populations are more likely to be affected by wildfire disasters because they lack the resources to prepare for, respond to, and recover from a wildfire. Low income is considered the strongest predictor for compromised health and ability to recover from a disaster. Low-income residents are generally disproportionally impacted by wildfires because they lack the financial resources and time to take proactive measures in advance of a wildfire, are less likely to be able to evacuate or relocate, experience more acute emotional stress, are more likely to be overlooked by emergency response services, and are less likely to have adequate property insurance so they bear a greater burden from property damage following a wildfire. People without access to a car are less likely to evacuate or access emergency response centers.

Populations with disabilities, especially those with mobility issues and medical conditions, are likely to have a reduced ability to respond to natural disasters, including wildfires. Older populations and young children are particularly sensitive to health problems related to wildfire smoke. Older

84 https://www.getawair.com/blog/how-the-2018-camp-fire-impacted-air-quality, accessed on June 19, 2024. 85 https://ww2.arb.ca.gov/news/new-analysis-shows-spikes-metal-contaminants-including-lead-2018-camp-firewildfire-smoke; accessed on June 18-19, 2024. 86 https://journalistsresource.org/health/wildfires-longterm-impact-on-health/ accessed on November 12, 2023. 87 Grant, E. and Runkle, J., 2022, Long-term health effects of wildfire exposure: A scoping review: The Journal of Climate Change and Health, Vol. 6, 100110
(https://www.sciencedirect.com/science/article/pii/S2667278221001073), accessed Nov. 12, 2023.

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populations are more likely to have pre-existing medical conditions or compromised mobility that can limit or hinder their ability to respond to a wildfire. Older populations and children are both particularly susceptible to air pollution, such as particulates, associated with wildfire smoke. Based on a nationwide comparison, several census tracts in Santa Monica are considered to have a high percentage of vulnerable populations.

Such vulnerable communities may be less able to receive notice of nearby fires, vacate, or protect themselves and their belongings from direct and indirect fire effects. These populations may also be more exposed to unhealthy levels of wildfire smoke. For example, houses without air conditioning units or air purifiers may experience lower air quality inside their homes. Finally, because the population in the Western US is expected to increase and get older, and fires are expected to become more common, larger, and more destructive, the number of people exposed to wildfire will increase.

This in turn means that an increasing number of vulnerable people will be impacted by the hazard of wildfire.

Ash can irritate the skin of both humans and animals, and affect the leaves of healthy vegetation.

Wildfire debris, ash and sediment can also change the chemistry of ponds and other bodies of water, killing aquatic life and the animals that depend on them. The Palisades Fire presented new challenges to coastal communities as wildfire debris was deposited into the Santa Monica Bay from oceanfront homes that burned in the fire and storm drains from inland burn zones. This prompted the temporary closure of ocean waters for recreational use and a robust, multi-jurisdictional effort to test ocean waters, sand and wildfire sediment to evaluate safety. Large wildfires release large quantities of carbon dioxide and other greenhouse gases into the atmosphere, which in turn impact and exacerbate climate change. To avoid the flames and smoke, wild animals may migrate into more densely populated areas where they are forced to come in contact with humans. Vehicular collisions with some of these animals may occur. The reduced vegetation cover results in loss of habitat for many animal species.

Fires usually last only a few hours or days, but their effects can last much longer, especially in the case of intense fires that develop in areas where large amounts of dry, combustible vegetation have been allowed to accumulate. The lack of vegetation cover following a wildfire typically results in soil erosion. If wildland fires are followed by a period of intense rainfall, debris flows off the recently burned hillsides can develop (see Section 9). Flood control facilities may be severely taxed by the increased flow from the denuded hillsides and the resulting debris that washes down. This in turn can impact water quality and water supply to downstream watersheds. If flood control structures are overwhelmed, widespread damage can ensue in areas down gradient from these failed structures.

Other effects of wildfires and structure fires in general are financial and social. Homeowners who lose their house to a fire may not be able to recover financially and emotionally for years to come.

Businesses that burn impact both the business owner, employees, and client base that are dependent on that business’s services. Even businesses not directly in the fire zone are impacted, with a clientele that is displaced. Tourism may also be significantly impacted for the region surrounding the wildfire, due to environmental concerns and the closure of popular recreational and tourist activities.

Transportation routes that are necessary for commerce may be closed or impacted even during recovery phases, as crews work to rebuild infrastructure and damaged properties, and clear debris.

For example, PCH in the Santa Monica-Malibu region was closed from January 7, 2025 to May 23, 2025 as a result of the Palisades fire. Wildfires have a significant impact on the insurance industry, typically resulting in increased premiums, policy changes, and even denial of future coverage for Local Hazard Mitigation Plan Section 10
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homeowners in high-risk areas. In addition, buildings that are destroyed by fire are usually eligible for re-assessment, which reduces income to local governments from property taxes.

Wildfires near Santa Monica can also stress fire and emergency management services across Los Angeles County, and disrupt regional transportation and utility systems. Wildfires can cause major community-wide disturbances, like evacuations, power outages, economic losses, road and school closures, and disruptions to recreational activities. The 2025 Palisades fire destroyed several elementary schools and damaged the high-school in Pacific Palisades. Several elementary schools and Palisades Charter High School have relocated to Santa Monica, made possible through the City’s emergency order relaxing permitting requirements for schools. This enabled schools to quickly convert non-traditional spaces, such as a vacant department store or office space, into temporary school environments. As discussed above, many of the displaced households sought alternate temporary (or permanent) housing elsewhere, including in Santa Monica. This raised rental and realestate prices, with price gouging reported in some areas. Rebuilding efforts are impacted by the increased costs of materials and labor, and in insurance premiums, all of which impact economically and socially disadvantaged populations more.

FIRE HAZARD MITIGATION ACTIVITIES
Hazard mitigation programs in wildfire hazard areas typically include:
• fire prevention,
• vegetation management,
• construction requirements, and
• public awareness.

There are both State and local legal requirements designed to mitigate the hazard of fires. These requirements are discussed below under each of the four major groups of hazard mitigation programs. There are also specific activities that property owners and local communities can do to further reduce their hazard, although not required by law. Some of these activities are also described further below.

Fire Prevention
Fire prevention aims to reduce the incidence and extent of fire by preventing wildfires from occurring in the first place. In the 20th century, a variety of fire prevention programs were developed and implemented by Federal, State, and local agencies. These programs typically included education, engineering, patrolling, code enforcement, and signing (Greenlee and Sapsis, 199687F 88). In the latter
half of the 20th century, for example, Smokey Bear was one of the best-known characters in the U.S., attesting to the success of the public education programs aimed at fire prevention at the time.

Quantitative studies conducted in the 1990s showed that fire losses arising from human fires, especially those caused by children, had dropped substantially, in some cases by as much as 80 percent.88F
89 Therefore, fire prevention is a well-understood program with a high degree of success.

However, as discussed previously, by preventing wildfires from occurring, fuel loads in forests and

88 Greenlee, J.M., and Sapsis, D.B., 1996, Prefire effectiveness in fire management: A summary and a review of the state-of-knowledge. Fairfield, WA: International Association of Wildland Fire. 89 Ibid.

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natural areas increased, which in turn increased the potential for high intensity wildfires and resultant damage to both the natural environment and adjacent communities in the WUI. Therefore, it is now recognized that fire education and prevention need to be complemented with several other programs that help reduce the losses resulting from wildfires.

Vegetation Management
Experience and research have shown that vegetation management is an effective means of reducing the wildland fire hazard. Hazard reduction and fuel modification are the two methods that communities and property owners most often employ to reduce the risk of fire at the WUI. Both methodologies use the principle of reducing the amount of combustible fuel available, which reduces the amount of heat, associated flame lengths, and the intensity of the fire that would threaten adjacent structures. In forested areas, prescribed fire may also be used for vegetation management.

Hazard reduction includes requirements for the maintenance of existing trees, shrubs, and ground cover to reduce the amount of fuel on those sides of any structure that face the WUI. These requirements include: clearing all dead or dying foliage; planting fire-resistive vegetation; keeping clearances between tree stands, bushes and shrubs, and between trees and structures; irrigating ground covers; storing firewood and combustible materials away from habitable structures; using fire-resistant roofing and construction materials; cleaning vegetation debris from roofs and rain gutters; and using spark arresters on chimneys.

Fuel modification involves the removal of vegetation around a structure, typically a distance of at a minimum 30 feet, and the planting of native, drought-tolerant and fire-resistant vegetation beyond that. The types and density of approved plants varies depending on distance from the structure being protected.

The purpose of these methods is to reduce the hazard of wildfire by establishing a defensible space around buildings or structures. Defensible space is defined as an area, either natural or man-made, where plant materials and natural fuels have been treated, cleared, or modified to slow the rate and intensity of an advancing wildfire, and to create an area for firefighters to suppress the fire and save the structure. These standards require property owners in the WUI to conduct maintenance, modifying or removing non-fire-resistive vegetation around their structures to reduce the fire danger.

In VHFHSZs such as that now mapped in the northern portion of Santa Monica, State law requires a 100-foot defensible space. Specifically, State law states that “a person who owns, leases, controls, operates, or maintains a building or structure in, upon, or adjoining a mountainous area, forestcovered lands, shrub-covered lands, grass-covered lands, or land that is covered in flammable material, shall maintain 100 feet of Defensible Space.”89F 90 Even before the northern portion of Santa Monica was zoned as having a high or very high fire hazard, property owners in the City were required to mitigate the fire hazard in their properties by implementing vegetation management practices that include the abatement of uncontrolled or high weeds, brush, or other plant material that if dry can create a fire hazard. Specifically, the Santa Monica Municipal Code (Chapter 7, Section 7.44) defines weeds to include brush or plants “which

90 https://readyforwildfire.org/wp-content/uploads/2024/07/Defensible-Space-and-the-Law-Factsheet-Revisions-Jan2024.pdf. Specific requirements can be found in ublic Resource Code (PRC) § 4291, 14 California Code of Regulations (CCR) § 1299.03, Board of Forestry (BOF) General Guidelines, California Fire Code (CFC) § 505.1, and California Building Code (CBC) § 2113.9.2.

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attain such growth as to become, when dry, a fire menace to adjacent improved property,” … and “dry grass, stubble, brush or other flammable material which endangers the public safety by creating a fire hazard…” These weeds are considered a public nuisance. Moreover, the City’s Director of Public Works has the authority to give the property owner of record a notice to abate the hazard by properly disposing the weeds located on their property. The notice is served via registered mail addressed to the owner or agent to the last known address. A copy of the notice is also posted on the property. The owner or agent has five days, not counting the day the notice was posted, to completely dispose of the weeds described in the notice. If the responsible individual does not abate the hazard during that time period, the City may take further action, with the Director of Public Works authorized to retain a contractor to dispose of the weeds. The cost of the weed abatement, including incidental expenses, is made a lien upon the property.

Prescribed fires are deliberately set by CAL FIRE and the U.S. Forest Service under carefully controlled and monitored conditions for the purpose of removing brush and other undergrowth that can fuel uncontrolled fires. Prescribed burning is used to alter, maintain or restore vegetative communities, achieve desired resource conditions, and protect life and property that would be degraded by wildland fire. Prescribed fire is only accomplished through managed ignition and should be supported by planning documents and appropriate environmental analyses.

Construction Requirements
Building construction standards for such items as roof coverings, fire doors, and fire-resistant materials help protect structures from external fires and contain internal fires for longer periods, limiting the spread of fire to adjacent structures. Fire-resistant materials can help reduce the impact of not only wildfires, but also structure fires. Many of these are legal requirements spelled out in the California Building Code (CBC) and the California Fire Code (CFC), including CBC § 2113.9.2 and Chapter 7A, and CFC § 505.1.

The portion of a structure most susceptible to ignition from a wildland fire is the roof, due to the deposition of burning cinders or brands. Burning brands or embers are often deposited far in advance of the actual fire by winds. Roofs can also be ignited by direct contact with burning trees and large shrubs. The danger of combustible wood roofs, such as wooden shingles and shakes, has been known to firefighting professionals since 1923, when California’s first major urban fire disaster occurred in Berkeley. It was not until 1988, however, that California was able to pass legislation calling for, at a minimum, Class C roofing in fire hazard areas. Then, in the early 1990s, there were several other major fires, including the Paint fire of 1990 in Santa Barbara, the 1991 Tunnel fire in Oakland/Berkeley, and the 1993 Laguna Beach fire, whose severe losses were attributed in great measure to the large percentage of combustible roofs in the affected areas. In 1994-1996, new roofing materials standards were approved by California for VHFHSZs. Today, the roofing standards for new habitable structures in VHFHSZs, SRAs, and in the WUI are spelled out in Chapter 7A of the California Building Code. Section 8.12.070 of the 2022 Santa Monica Building Code spells out roofing standards for all new structures and new roofs in the city.

To help consumers determine the fire resistance of the roofing materials they may be considering, roofing materials are rated as to their fire resistance into three categories that are based on the results of test fire conditions that these materials are subjected to under rigorous laboratory conditions, in accordance with test method ASTM-E-108 developed by the American Society of Testing Materials.

The rating classification provides information regarding the capacity of the roofing material to resist Local Hazard Mitigation Plan Section 10
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a fire that develops outside the building on which the roofing material is installed, taking into consideration wind conditions. The three ratings are as follows:

Class A: Roof coverings that are effective against severe fire test exposures.

Class B: Roof coverings that are effective against moderate fire test exposures.

Under such fire exposures, roof coverings of these classes:
o Are not readily flammable;
o Afford a high degree of fire protection to the roof deck; o Do not slip from position; and
o Do not produce flying brands.

Class C: Roof coverings that are effective against light fire exposures. Under such exposures, roof coverings of this class:
o Are not readily flammable;
o Afford a measurable degree of fire protection to the roof deck; o Do not slip from position; and
o Do not produce flying brands.

Non-Rated Roof coverings have not been tested for protection against fire exposure. Under such exposures, non-rated roof coverings:
o May be readily flammable;
o May offer little or no protection to the roof deck, allowing fire to penetrate into attic space and the entire building; and
o May pose a serious fire brand hazard, producing brands that could ignite other structures a considerable distance away.

The City of Santa Monica enforces a Class A or Class B roofing material requirement for all new structures and new roofs. Specifically, “the use of non-fire retardant wood shingles or non-fire retardant shakes for new or replacement roofing is prohibited. Class A or B assemblies and roof coverings shall be listed and tested in accordance with ASTM E108 or UL 790.”90F 91 Attic ventilation openings are also a concern regarding the fire survivability of a structure. Attics require significant amounts of cross-ventilation to prevent the degradation of wood rafters and ceiling joists. This ventilation is typically provided by openings to the outside of the structure, but these opening can provide pathways for burning brands and flames to be deposited within the attic.

Therefore, it is important that all ventilation openings be properly screened to prevent this.

Additional prevention measures that can be taken to reduce the potential for ignition of attic spaces is to “use non-combustible exterior siding materials and to site trees and shrubs far enough away from the walls of the house to prevent flame travel into the attic even if a tree or shrub does torch” (Fisher, 1995).

The type of exterior wall construction used can also help a structure survive a fire. Ideally, exterior walls should be made of non-combustible materials such as stucco or masonry. During a wildfire, the dangerous active burning at a given location typically lasts about 5 to 10 minutes (Fisher, 1995),

91 Section 8.12.070 of the Santa Monica Building Code (2022 edition adopted 10/25/22 under Ord. No. 2727CCS § 4).

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so if the exterior walls are made of non-combustible or fire-resistant materials, the structure has a better chance of surviving.

Similarly, the type of windows used in a structure can help reduce the potential for fire to impact a structure. Single-pane, annealed glass windows are known for not performing well during fires; thermal radiation and direct contact with flames cause these windows to break because the glass under the window frame is protected and remains cooler than the glass in the center of the window.

This differential thermal expansion of the glass causes the window to break. Larger windows are more susceptible to breakage when exposed to high heat than smaller windows. Multiple-pane windows, and tempered glass windows perform much better than single-pane windows91F

92. Fisher
(1995) reported that in Australia, researchers noticed that the use of metal screens helps protect windows from thermal radiation. Insect screens made of bronze, fiberglass and aluminum all reportedly improve the performance of glass subjected to radiant exposure, but not to direct, flame contact exposure92F

93. The City of Santa Monica Building and Safety Division enforces requirements of the Building Code with respect to exterior wall construction and window material requirements, and the City’s Fire Department reviews buildings for compliance with the Fire Code.

Public Awareness
Fire prevention can include limiting access to fire hazard areas during certain times of the year. The wildfire susceptibility of an area changes throughout the year, and from one year to the next, in response to local variations in precipitation, temperature, vegetation growth, and other conditions.

When the fire danger in an area is deemed to be of special concern, local authorities can rely on increased media coverage and public announcements to educate the local population about being fire safe. These announcements are typically triggered by the National Weather Service (NWS), the Federal agency that monitors lightning, wind and humidity conditions.

If the NWS determines that the current or expected meteorological conditions are likely to contribute to extreme fire danger or fire behavior, the NWS issues Fire Weather Watches or Red Flag Warnings for the area impacted, as appropriate. These conditions and criteria93F 94 as they pertain to southern
California west of the San Gabriel and San Bernardino Mountains (and thus the Santa Monica area) include:
• Dry lightning: This is a lightning event that is not accompanied by sufficiently wet fuels that have been identified as critically dry. Significant precipitation is defined as ranging from 0.05 inches for grass or brush, to 0.15 inches for closed-canopy timer and heavy fuels. Watches and warnings are issued when dry lightning is expected to be widespread. As described previously, lightning only causes a small percentage of the wildfires in Los Angeles County. • Wind and humidity: Watches and warning are issued if relative humidity is less or equal to 15%, with sustained winds equal to or greater than 25 miles per hour (mph) and/or frequent gusts equal to or greater than 35 mph with an expected duration of 6 hours or more, or if relative humidity is less than or equal to 10% for an expected duration of 10 hours or more regardless of wind presence.

92 https://ucanr.edu/sites/Wildfire/Side_of_House/Windows/, accessed October 4, 2023. 93 https://ucanr.edu/sites/Wildfire/Side_of_House/Windows/, accessed October 4, 2023. 94 94 https://www.weather.gov/gjt/firewxcriteria, accessed October 4, 2023.

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A Fire Weather Watch alerts land managers, fire suppression agencies and the public that upcoming weather conditions (consisting of a combination of surface relative humidity, sustained surface wind, and fuel moisture levels94F
95) could cause wildfires or extreme fire behavior. It means that critical fire weather conditions are possible but are not imminent or occurring. Appropriate response to a Fire Weather Watch is to prepare fire response equipment and personnel.

A Red Flag Warning is issued when the conditions are right for extreme wildfire events. Red Flag Warnings are issued when fire conditions are ongoing or expected to develop shortly. Appropriate response to a Red Flag Warning is for local, affected fire agencies and land managers to take action, and for everyone to avoid or be extremely careful with open flames. Residents in and near VHFHSZs should prepare to evacuate with little notice in the event of a wildfire developing in their neighborhood. An enhanced version of a Red Flag Warning referred to as an Extreme Red Flag Warning was first issued by the NWS on October 29, 2019 in the southern California region as a result of very strong Santa Ana winds. This warning means that, due to a combination of strong, prolonged winds, very low humidity, and very dry fuels, there is a heightened potential for fire growth and extremely dangerous fire behavior.

In addition, NWS will utilize the phrase “Potentially Dangerous Situation (PDS)” to heighten the public’s awareness and urgency in action during Red Flag Warning events. This designation is used for many types of weather events, highlighting extreme and potentially life-threatening conditions.

PDS Red Flag Warning events were declared in December 2024 when the Franklin Fire occurred and in January 2025 before the Palisades and Eaton fires.

Prior to issuing a Fire Watch or Red Flag Warning, the NWS will confer with local fire and emergency management agencies to discuss fuel conditions and local concerns. This is intended to assist local agencies in allocating or moving resources to the affected areas in anticipation of increased fire activity. However, ultimate responsibility to issue a fire watch or warning rests with the NWS forecaster.95F
96 Utility companies such as Southern California Edison (SCE) use these forecasts and their own modeling to assess the potential impact to their electric distribution system, especially electric lines and circuits. If their analysis indicates that circuits might be impacted by the extreme fire conditions, including strong winds, dry vegetation, and low humidity, the utility may temporarily shut off the power to reduce the risk of wildfire caused by downed or damaged utility equipment.

This is called a Public Safety Power Shutoff (PSPS). No PSPSs have been implemented by SCE in Santa Monica since October 2021.96F
97 Local authorities can rely on increased media coverage and public announcements regarding fire watches and red flag warnings to educate the local population about being fire safe. For example, to reduce the potential for wildfires during fire season, hazardous fire areas can be closed to public access during at least part of the year. Typically, the fire season in southern California begins in May and lasts until the first rains in November, but local counties or jurisdictions can opt to start the fire season earlier and end it later.

95 See https://www.weather.gov/lwx/warningsdefined for additional information. 96 https://gacc.nifc.gov/oscc/predictive/weather/myfiles/Watches_and_Warnings_for_California.htm, accessed May 2025. 97
https://capuc.maps.arcgis.com/apps/dashboards/ecd21b1c204f47da8b1fcc4c5c3b7d3a, accessed October 2025.

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Use of signage during high and extreme fire conditions along the roads adjoining the VHFHSZ mapped within the city, can help reduce the fire hazard by alerting and educating motorists, residents and visitors alike, about the potential fire hazard in the area. Santa Monica Office of Emergency Management will issue social media alerts of Red Flag Warning conditions. Their fire preparedness website provides guidance on actions to take to prepare for wildfires and potential local evacuations. It recommends residents have an evacuation checklist and kit ready. It also suggests that all residents who are planning to visit the Santa Monica Mountains or other mountains in the region first check if there are any wildfire-related restrictions or guidelines in place. It is best to cancel the hike or trip if a wildfire is burning nearby.97F 98 Restricted public access to hiking trails in and around the city of Santa Monica during the fire season may help reduce the opportunity for human-caused wildfires in the area. Continued use of signs during high and extreme fire conditions along the freeways and roads that cut through the wildland areas in the city and adjacent areas can also help reduce the fire hazard by alerting and educating motorists and residents.

Fire protection in the WUI relies heavily on landowners taking measures personally to protect their properties. Property owners are more likely to take the initiative if they are informed of the risk.

Therefore, public education and awareness should play a greater role in the areas identified as having a wildfire hazard, with property owners encouraged to exercise care to reduce the risk of fire in their property. Some of the tasks that property owners and residents can take on are listed below.

This list is not all-inclusive, but provides a starting point and framework to work from. • Mow and irrigate your lawn regularly, but do not mow during the hottest time of the day • Dispose of cuttings and debris promptly, according to local regulations • Store firewood away from structures
• Be sure the irrigation system is well maintained
• Use care when refueling garden equipment and maintain it regularly • Store and use flammable liquids properly
• Dispose of smoking materials carefully
• Do not light fireworks. All fireworks are illegal in Santa Monica, except for aerial public fireworks display approved by City Council, the use of fireworks for special effects in entertainment productions as authorized by State law, and the use or transportation of fireworks by State or Federal authorities (Section 8.40.020 of the Municipal Code). • Become familiar with local regulations regarding vegetation clearings, disposal of debris, and fire safety requirements for equipment
• Follow manufacturers’ instructions when using fertilizers and pesticides • When building, selecting or maintaining a home, consider the slope of the terrain. Be sure to build on the most level portion of the lot, since fire spreads rapidly on slopes, even minor ones.
• Use construction materials that are fire-resistant or non-combustible whenever possible, in accordance with local requirements and the California Building and Fire Codes

98 https://www.santamonica.gov/how-to-prepare-for-wildfires-in-santa-monica, accessed May 2025.

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• For roof construction, the City of Santa Monica requires a minimum Class B rating. Nonfire-retardant wood shingles or non-fire-retardant shakes for new or replacement roofing are prohibited (Santa Monica 2022 Building Code Section 8.12.070). • Constructing a fire-resistant sub-roof can add protection. • On exterior wall cladding, fire-resistive materials such as stucco or masonry are much better than vinyl, which can soften and melt.
• Install an approved automatic fire sprinkler system and/or install portable fire extinguishers. The City of Santa Monica has specific requirements for sprinklers and the installation of portable fire extinguishers.
• Display the assigned address number so that it is visible from the street and alley upon which the address is based. The City of Santa Monica requires that the numbers in the signs be a minimum of 6 inches high for commercial structures, and 4 inches high for interior suites, offices, and rooms in commercial structures, and in one- and two-family dwellings. The numbers need to have a minimum stroke width of 0.5 inches, and contrast with their background (Santa Monica 2022 Building Code Section 8.40.020). • So that everyone has a way out, provide at least two ground level doors for safety exits and at least two means of escape (doors or windows) in each room • Keep gutters, eaves, and roof clear of leaves and other debris • Occasionally inspect your home, looking for deterioration, such as breaks and spaces between roof tiles, warping wood, or cracks and crevices in the structure • If an all-wood fence is attached to your home, a masonry or metal protective barrier between the fence and house is recommended
• Use non-flammable metal when constructing a trellis and cover it with high-moisture, non-flammable vegetation
• Prevent combustible materials and debris from accumulating beneath patio decks or elevated porches. Screen, or box in, areas that lie below ground level with wire mesh • For properties along the northern and northeastern edges of the city and properties facing steep slopes, make sure that elevated wooden decks are not located at the top of a hill where it will be in the direct line of a fire moving up slope • Install automatic seismic shut-off valves for the main gas line to your house. Information for approved devices, as well as installation procedures, is available from the Southern California Gas Company.

In California, properties located in fire hazard areas need to be disclosed in real estate transactions; that is, real-estate sellers are required to inform prospective buyers whether or not the property is located within an area that could be impacted by a wildland fire [California Civil Code Section 1103(c)(6)]. This disclosure requirement applies to properties within a State Responsibility Area.

As of July 1, 2021, California Assembly Bill 38 (AB 38) states that the seller of a residential property located in a High and Very High Fire Hazard Severity Zone (HFHSV or VHFHSZ must submit documentation of compliance with the locally adopted defensible space requirements prior to the close of escrow, or enter into an agreement with the buyer pursuant to the buyer obtaining documentation of compliance. The bill also states that on or after January 1, 2021, the seller of any real property located in a high or very high fire hazard severity zone is to provide a prescribed disclosure notice to the buyer, if the home was constructed before January 1, 2020, of information Local Hazard Mitigation Plan Section 10
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relating to fire hardening improvements on the property and a list of specified features that may make the home vulnerable to wildfire and flying embers and which features, if any, that exist on the home of which the seller is aware. These requirements apply to properties in Santa Monica located in the newly designated HFHSZ and VHFHSZ.

WILDFIRE RESOURCE DIRECTORY
Local Resources
Santa Monica Fire Department
The Santa Monica Fire Department is responsible for fire suppression, pre-hospital emergency medical services, hazardous materials release oversight and response, and fire and life safety community outreach services for the City of Santa Monica. The Fire Department responds to a variety of medical and rescue calls, vegetation and structure fires, vehicle accidents, public assistance, and false alarms. Organized fire suppression services in the area date back to 1875, when the Crawford Hook and Ladder Company was formed by six local residents. Then, in March 1889, less than three years after the city was incorporated, the Santa Monica Hose and Ladder Company was founded.

This was the beginning of the Santa Monica Fire Department as it is known today.

Firefighting and emergency response resources in Santa Monica are provided from the five fire stations listed in Table 10-5 below. The locations of these fire stations are shown on Figures 10-4, 3-1 and Plates H-3 and H-17 in Appendix H. Combined, these fire stations are manned by 105 emergency response (suppression and rescue) personnel, with a combined minimum daily staffing for the five stations of 35 personnel. Resources and staffing assigned to each of these fire stations are summarized in Table 10-5 also.

The Santa Monica Fire Department administrative offices, with 14 budgeted personnel, and an allhazards fire prevention division, also with 14 budgeted personnel, are housed at the City’s Public Safety Facility at 333 Olympic Drive. Staffing includes a Fire Prevention Coordinator, who oversees public education programs. The Fire Department also has an accredited fire academy located at 2500 Michigan Avenue that is staffed by 3 budgeted personnel. The general telephone number for the Santa Monica Fire Department is (310) 458-8652. For emergencies, dial 911.

Based on data provided by Citygate Associates (2020) the five fire stations in the city of Santa Monica respond to approximately 17,000 incidents a year. Note that about 70% of the responses are for medical and rescue emergency calls. This is typical of most communities. In Santa Monica, “all response personnel are trained to either the Emergency Medical Technician (EMT) level, capable of providing Basic Life Support (BLS) pre-hospital emergency medical care, or EMT Paramedic level, capable of providing Advanced Life Support (ALS) pre-hospital emergency medical care.”98F 99 Medical
emergencies are handled by the closest available engine company. Therefore, on average, each fire station responds to nearly 2,400 calls a year, although this case load is not equally distributed among all five fire stations. Specifically, Fire Stations 1, 2 and 3 are located in and service some of the most densely populated areas. Citygate Associates (2020) determined that all planning areas in the city, except for planning zone 5, which covers the area around the airport, have a moderate building fire risk. Planning zone 5 is considered to have a low building fire risk.

99 Citygate Associates, 2020, Community Risk Assessment / Standards of Cover Analysis, City of Santa Monica, CA, Volume 1 of 2: Technical Report.

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Table 10-5: Santa Monica Fire Department Stations, Resources and Minimum Daily Staffing Station No.;
Address Year Built Assigned Resourcesδ Minimum Daily Staffing 1; 1337 7th Street 2020
Engine 1
Engine 6
Truck 1
Rescue Utility 1
Community Response Unit 1 (ambulance)
Battalion 1
Battalion 2 (reserve)
Rescue Ambulance 1 (Reserve)
15 2; 222 Hollister
Avenue 2003
Engine 2
USAR 2
USAR Utility 2
Rescue Ambulance 2 (reserve)
4 3; 1302 19th Street 1971
Engine3
Engine 4
Engine 8 (reserve)
8 5; 2450 Ashland
Avenue 1980
Engine 5
Aircraft Rescue 5
ARFF Utility 5
HazMat Unit 5
Engine 9 (reserve)
Truck 2 (reserve)
Rescue Ambulance 5 (reserve)
4 7;
1100 Palisades
Beach Road
(Pacific Coast
Hwy.)
2019
Engine 7
Beach Medical Vehicle 7
Utility 7 4
δ Staffed resources are in bold; other resources, including reserves, are staffed as needed by on-duty station personnel or recalled off-duty personnel
Sources: City of Santa Monica Fire Department, with data extracted from Citygate Associates, LLC (2020) and https://fire.fandom.com/wiki/Santa_Monica_Fire_Department (accessed on August-September 2023).

The Insurance Services Office (ISO) provides rating and statistical information for the insurance industry in the United States. To do so, ISO evaluates a community’s fire protection needs and services, and assigns each community evaluated a Public Protection Classification (PPC) rating. The rating is developed as a cumulative point system, based on the community’s fire-suppression delivery system, including fire dispatch (operators, alarm dispatch circuits, telephone lines available), fire department (equipment available, personnel, training, distribution of companies, etc.), and water supply (adequacy, condition, number and installation of fire hydrants). Insurance rates are based upon this rating. The worst rating is a Class 10. The best is a Class 1. Santa Monica has maintained a Class 1 ISO rating since 2012.

Automatic and Mutual Aid Agreements
Firefighting agencies often team up and work together during emergencies. These teaming arrangements are handled through automatic and mutual aid agreements, which obligate fire Local Hazard Mitigation Plan Section 10
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departments to help each other under pre-defined circumstances. Automatic aid agreements obligate the nearest fire company to respond to a fire regardless of the jurisdiction. Mutual aid agreements obligate fire department resources to respond outside of their district upon request for assistance.

The California Disaster and Civil Defense Master Mutual Aid Agreement (California Government Code Section 8555-8561) states: “Each party that is signatory to the agreement shall prepare operational plans to use within their jurisdiction, and outside their area.” These plans include fire and non-fire emergencies related to natural, technological, and war contingencies. The State of California, all State agencies, all political subdivisions, and all fire districts signed this agreement in 1950.

Santa Monica is part of the Los Angeles County Operational area, and more specifically, a member of Disaster Management Area A. The Operational Area is part of the Standardized Emergency Management System (SEMS), further described below, that promotes effective disaster management, response and cooperation across jurisdictional boundaries. Other jurisdictions, in addition to Santa Monica, that are members of Operational Area A include Beverly Hills, Culver City and West Hollywood. As a result of being part of the same Operational Area group, all of these jurisdictions have mutual aid agreements that allow them to obtain additional emergency resources, as needed, from non-affected members in the group. On February 13, 2024, Santa Monica City Council approved an Automatic Mutual Aid Agreement with Los Angeles Fire Department.

Numerous other agencies are available to assist the City if needed. Locally, these include the City’s Office of Emergency Management, the City’s Police Department and the California Highway patrol.

The City’s Office of Emergency Management oversees the City’s police and fire dispatch operations, emergency alerting capabilities, as well as manages the City’s multi-department Emergency Operations Center that coordinates large-scale emergency response operations. The City’s Police Department and/or California Highway patrol, depending on the location of the incident, would facilitate evacuations and prevent people from traveling to the evacuated areas to watch their operations, as this can hinder fire suppression and emergency response efforts.

Several other State and Federal agencies have roles in fire hazard mitigation, response and recovery, depending on the type of incident and its location. These agencies include the Los Angeles County Fire Department, the Los Angeles County Chief Executive Office, the California Division of Forestry and Fire Protection, the Office of the State Fire Marshal, the California Governor’s Office of Emergency Services, FEMA, and several agencies under the U.S. Department of the Interior including the Bureau of Land Management and Office of Aviation Services, the National Weather Service, and, in extreme cases, the Department of Defense. In forest areas (and therefore not applicable to Santa Monica), other agencies that may be involved include the Fish and Wildlife Service, National Park Service, US Forest Service, National Association of State Foresters, and the Department of Agriculture. Private companies and individuals may also be asked to provide assistance in some cases. Contact information for several of these local, State and Federal agency resources are provided at the end of this section.

Standardized Emergency Management System (SEMS)
The SEMS law refers to the Standardized Emergency Management System described by the Petris Bill (Senate Bill 1841; California Government Code Section 8607, made effective January 1, 1993) that was introduced by Senator Petris following the 1991 Oakland fires. The intent of the SEMS law Local Hazard Mitigation Plan Section 10
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is to improve the coordination of State and local emergency response in California. It requires all jurisdictions within the State of California to participate in the establishment of a standardized statewide emergency management system.

When a major incident occurs, the first few moments are absolutely critical in terms of reducing loss of life and property. First responders must be sufficiently trained to understand the nature and the gravity of the event to minimize the confusion that inevitably follows catastrophic situations. The first responder must then put into motion relevant mitigation plans to further reduce the potential for loss of lives and property damage, and to communicate with the public. According to the State’s Standardized Emergency Management System, local agencies have primary authority regarding rescue and treatment of casualties, and making decisions regarding protective actions for the community. This on-scene authority rests with the local emergency services organization and the incident commander.

Depending on the type of incident, several different agencies and disciplines may be called in to assist with emergency response. Agencies and disciplines that can be expected to be part of an emergency response team include medical, health, fire and rescue, police, public works, emergency management, and coroner. The challenge is to accomplish the work at hand in the most effective manner, maintaining open lines of communication between the different responding agencies to share and disseminate information, and to coordinate efforts.

Emergency response in every jurisdiction in the State of California is handled in accordance with SEMS, with individual City agencies and personnel taking on their responsibilities as defined by the City’s Emergency Plan. This document describes the different levels of emergencies, the local emergency management organization, and the specific responsibilities of each participating agency, government office, and City staff.

The framework of the SEMS system is the following:
• Incident Command System – a standard response system for all hazards that is based on a concept originally developed in the 1970s for response to wildland fires • Multi-Agency Coordination System – coordinated effort between various agencies and disciplines, allowing for effective decision-making, sharing of resources, and prioritizing of incidents
• Master Mutual Aid Agreement and related systems – agreement between cities, counties and the State to provide services, personnel and facilities when local resources are inadequate to handle and emergency
• Operational Area Concept – coordination of resources and information at the county level, including political subdivisions within the county; and • Operational Area Satellite Information System - a satellite-based communications system with a high-frequency radio backup that permits the transfer of information between agencies using the system.

The SEMS law requires the following:
• Jurisdictions must attend training sessions for the emergency management system.

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• All agencies must use the system to be eligible for funding for response costs under disaster assistance programs.
• All agencies must complete after-action reports within 120 days of each declared disaster.

Santa Monica Office of Emergency Management
333 Olympic Drive, Santa Monica, CA 90401
(310) 458-2263
Email: [email protected]
https://www.santamonica.gov/departments/city-managers-office/office-of-emergency-management As mentioned briefly before, Santa Monica’s Office of Emergency Management oversees the City’s police and fire dispatch operations, emergency alerting capabilities, as well as manages the City’s multi-department Emergency Operations Center that coordinates large-scale emergency response operations. These services are provided by two divisions within the Office of Emergency Management, as follows: 1) Emergency Services and Preparedness, and 2) Public Safety Communications.

Emergency Services and Preparedness administers the implementation of extensive disaster planning, training and proactive community-based preparedness programs to ensure that the City is a disaster-resilient community. This division also oversees the operation of the City’s Emergency Operation Center (EOC), which provides a central command center for all City departments and external response stakeholders to collaboratively manage, plan, prevent, and recover from all events (planned and unplanned) and emergencies in the city.

Public Safety Communications provides joint communication services to the City’s Police and Fire Departments, including answering 911 and non-emergency phone calls, dispatching public safety resources, and providing emergency medical dispatch services and 911 education to the public.

Santa Monica Police Department
333 Olympic Drive, Santa Monica, CA 90401
(310) 458-8495
https://www.santamonica.gov/departments/police
Southern California Edison (SCE)
SCE may temporarily shut off power to an area or region to reduce the risk of a wildfire caused by failure of their equipment during dangerous fire weather conditions such as strong winds. Such a shutoff is referred to as a Public Safety Power Shutoff (PSPS). Residents can sign up to receive notifications of a potential PSPS. For additional information regarding PSPSs, refer to the links below. 2244 Walnut Grove Ave, Rosemead, CA 91770
(1-800) 655-4555
https://www.sce.com/outages-safety/outage-preparedness/outage-types/public-safety-powershutoff-psps/psps-faqs; https://www.sce.com/ Local Hazard Mitigation Plan Section 10
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2025 Wildfires & Urban Fires Page 10-56
County Resources
Los Angeles County Fire Department
(323).881-2411
https://fire.lacounty.gov/
Los Angeles County Chief Executive Office
Manages the Los Angeles County’s Operational Area and Disaster Management Areas 500 W. Temple St., Room 358, Los Angeles, CA, 90012
(213) 974-1311
https://ceo.lacounty.gov/;
https://data.lacounty.gov/datasets/lacounty::disaster-management-areas/about State Resources
California Division of Forestry & Fire Protection and
Office of the State Fire Marshal (OSFM)
715 P Street
PO Box 944246
Sacramento California 94244-2460
(916) 653-5123
https://www.fire.ca.gov/
https://osfm.fire.ca.gov/
California Governor’s Office of Emergency Services (Cal-OES) https://www.caloes.ca.gov/
California FireSafe Council (CFSC)
Non-profit organization that supports communities across the State in wildfire preparedness and resiliency through grant funding, programmatic support, and technical assistance. They provide resources and support for community-led wildfire resiliency efforts. Their activities include outreach and education; landscape, community and parcel level mitigation activities; and planning and community hardening.
7301 I Street, No. 236
Sacramento, CA 95814
(916) 648-3600
https://cafiresafecouncil.org/
Federal Resources and Programs
The role of the federal land managing agencies in the WUI is reducing fuel hazards on the lands they administer; cooperating in prevention and education programs; providing technical and financial assistance; and developing agreements, partnerships and relationships with property owners, local protection agencies, states and other stakeholders. These relationships focus on activities before a wildfire occurs, which render structures and communities safer and better able to survive a fire occurrence.

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Federal Emergency Management Agency (FEMA)
FEMA is directly responsible for providing fire suppression assistance grants and, in certain cases, major disaster assistance and hazard mitigation grants in response to fires. FEMA coordinates across federal agencies to help state, local, tribal and territorial partners respond to wildfires nationwide.

Federal support for fire management assistance through FEMA includes personnel, technical assistance and financial investments that help communities mitigate and respond to wildfires. Some of mitigation opportunities accessed through FEMA include the Hazard Mitigation Grant Program (HMGP), the Building Resilient Infrastructures and Communities (BRIC) program, and Fire Management Assistance Grants.
https://www.fema.gov/disaster/wildfire-actions
U.S. Department of the Interior
Large umbrella organization under which there are several bureaus that have roles in the management of public lands, the suppression and management of wildfires in national lands, and other similar issues. These bureaus include the Bureau of Land Management, the National Park Service, the Bureau of Safety and Environmental Enforcement, Office of Aviation Services, and the U.S. Fish and Wildlife Service.
https://www.doi.gov/
National Weather Service
The National Weather Service is the service line office within the Federal National Oceanic and Atmospheric Administration (NOAA) that provides weather, water and climate data, forecasts, warnings, and impact-based decision support services for the protection of life and property and enhancement of the national economy. This includes real-time mapping of fire weather watches and red fire warnings.
https://www.weather.gov/
https://www.weather.gov/fire/
Other National Resources
National Fire Protection Association (NFPA)
This is a U.S.-based international nonprofit organization devoted to eliminating death, injury, property damage, and economic loss due to fire, electrical, and related hazards. The NFPA website provides information on a variety of subjects including wildfires, industrial and chemical hazards, electrical hazards, home fire safety, and community risk reduction.

Public Fire Protection Division
1 Batterymarch Park, Quincy, MA 02169-7471
(800) 344-3555 and (1-617) 770-3000
https://www.nfpa.org/
National Interagency Fire Center (NIFC)
The NIFC in Boise, Idaho is the nation’s support center for wildland firefighting. NIFC is home to the national wildland fire management programs of the Department of the Interior’s Bureau of Land Management, National Park Service, U.S. Fish and Wildlife Service, and Bureau of Indian Affairs, and the U.S. Department of Agriculture’s Forest Service, in addition to the National Association of Local Hazard Mitigation Plan Section 10
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2025 Wildfires & Urban Fires Page 10-58
State Foresters, the U.S. Fire Administration, the National Weather Service, and the Department of Defense. The NIFC and its partners compile information about the current wildfire situation and statistics that encompass lands managed by federal, state, local, tribal, and private agencies, and summarize the current fire situation nationwide on a daily to weekly basis. The NIFC’s website provides information on ongoing wildfires, in addition to a variety of research and educational resources.
3833 S. Development Ave., Boise, Idaho 83705
(208) 387-5512
https://www.nifc.gov/
United States Fire Administration (USFA)
As an entity of the U.S. Department of Homeland Security’s Federal Emergency Management Agency (FEMA), the mission of the USFA is to support and strengthen fire and emergency medical services (EMS) and stakeholders to prepare for, prevent, mitigate and respond to all hazards through leadership, advocacy, coordination and support.

USFA, Planning Branch, Mitigation Directorate
16825 S. Seton Ave.

Emmitsburg, MD 21727
(301) 447-1035
https://www.usfa.fema.gov/
Additional Resources
Firewise USA
A program of the NFPA designed for communities and people who live in wildfire prone areas, that can also be of use to local planners and decision makers. The site offers online wildfire protection information and checklists, as well as listings of other publications, videos and conferences. (617) 770-3000
http://www.firewise.org/,
https://www.nfpa.org/Education-and-Research/Wildfire/Firewise-USA Insurance Services Office (ISO)
The Insurance Services Office (ISO), now a subsidiary of Verisk Analytics, developed a program used by the insurance industry to identify those areas where the potential loss due to wildfire is greatest. Their FireLine software uses satellite-imagery interpretation to evaluate the factors of fuel types, slope and roads (access) to develop risk ratings for communities. Most insurance companies that provide insurance services to homeowners in California now use this system. Their Community Hazard Mitigation group works with local fire and building departments, water agencies, and municipalities, and ranks their firefighting capabilities, as discussed above. https://www.isomitigation.com/
Publications
Refer to the footnotes of this document for a variety of publications that address wildland fire, structure fires, and fires after earthquakes.

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SECTION 11: CLIMATE CHANGE &

SEVERE WEATHER HAZARDS

WHY DO CLIMATE CHANGE AND SEVERE WEATHER POSE A THREAT TO THE CITY OF SANTA MONICA?
Climate change has caused rapid and widespread changes in the atmosphere, oceans, and the planet as a whole; the result, in great part, of human activities, especially the emissions of greenhouse gases (AR6 Synthesis Report and Headline Statements from the International Panel on Climate Change, 20230F
1 ). The impacts of climate change (Figure 11-1), which are being felt in California and around the world, include higher temperatures and more common extreme heat events, more severe wildfires, more frequent and intense droughts, flooding due to extreme precipitation events, and coastal flooding and erosion from sea level rise (Ehlers, 2022). These changes in climate impact human health (Figure 11-2), including injuries, illnesses, and deaths related to extreme heat and natural disaster events (floods and wildfires); air pollution from wildfire smoke; reduced water quality due to runoff from extreme precipitation events and sea-water intrusion into aquifers; impacts on food and water supplies from droughts; and increasing prevalence of certain diseases (Ehlers, 2022).

Figure 11-1: Impacts of Climate Change on California
Source: Ehlers (2022)

1 https://www.ipcc.ch/report/ar6/syr/resources/spm-headline-statements, accessed August 22, 2024.

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Figure 11-2: Health Impacts of Climate Change
Source: Ehlers (2022), who adapted the figure from one issued by the Centers for Disease Control and Prevention and Senate Office of Research.

According to statistics compiled and reported by the National Oceanic and Atmospheric Administration (NOAA), between 1980 and September 10, 2024 (the most recent date for which data were available), California experienced 46 climate/weather events that exceeded $1 billion in costs each. These events include droughts, floods, freezes, severe storms, and wildfires, with droughts and wildfires accounting for nearly 72% of the total losses. Table 11-1 below summarizes these data.

Table 11-1: Summary of Natural Hazard Events in California (1980-Sept. 2024) Costing >$1 Billion
Disaster Type No. of
Events Events/Year % Frequency Total Cost($ Billion) % of Total Costs Drought 14 0.3 30.4 10.0-20.0 10.7
Flooding 6 0.1 13.0 10.0-20.0 12.4
Freeze 3 0.1 6.5 10.0-20.0 10.0
Severe Storm 4 0.1 8.7 2.0-5.0 2.3
Wildfire 19 0.4 41.3 50.0-100.0 64.7
All Disasters 46 1.0 100.0 100.0-200.0 100.0
Source: National Oceanic and Atmospheric Administration (NOAA) National Centers for Environmental Information (NCEI) U.S. Billion-Dollar Weather and Climate Disasters (2024)1F 2 .
2 https://www.ncei.noaa.gov/access/billions/, DOI: 10.25921/stkw-7w73 accessed in August and September 2024.

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Table 11-1 above illustrates the economic cost that severe weather and climate change has had on California in the past four decades. The annual average for the entire 44 years (1980-2023 inclusive) is 1.0 events, whereas the annual average for the most recent complete five years (2019-2023 inclusive) is 1.8 events. The annual average number of events, and the costs per event, are expected to continue to rise as the effects of climate change become more pronounced. The 44 events listed on Table 11-1 are responsible for a reported 1,495 fatalities, although this number likely includes deaths in adjacent states that were also impacted by some of these disasters. The highest number of fatalities is associated with heat waves during droughts, followed closely by wildfires.

This chapter discusses the impacts of climate change and the climate change-related weather hazards the city of Santa Monica is likely to face in the coming decades, including impacts from:

1. extreme heat

2. drought

3. sea level rise, and

4. extreme windstorms
The hazards of extreme precipitation and wildfire, which are also becoming increasingly more common and damaging due to climate change, are discussed in detail in Sections 8 and 10, respectively, of this report. Each of the hazards in the list above is discussed individually in the following sub-sections, providing definitions for specific terms as appropriate, followed by a discussion on the climate change-related vulnerabilities anticipated for the city of Santa Monica.

This section is modeled after a similar chapter prepared for the Technical Background Report to the City’s Safety Element Update (2024). For information on the sources used, the reader is encouraged to review Chapter 5 in the Technical Background Report and the publications and sources referenced in this section. Please note that scientific and planning documents related to the impacts of climate change are being published at an astonishing rate and while we aimed to be as up-todate as possible in this report, given the pace of scientific inquiry into this subject, sections of this report may already be slightly obsolete at printing time.

SNAPSHOT OF SANTA MONICA’S CLIMATE AND WEATHER BASED ON

HISTORICAL DATA, AND ELEMENTS IMPACTING FUTURE FORECASTS The city of Santa Monica is located within the western coastal portion of Los Angeles County, and within the South Coast Air Basin. The regional climate2F 3 is considered semi-arid and is characterized
by warm summers, mild winters, infrequent seasonal rainfall, moderate daytime onshore breezes, and moderate humidity. Annual temperatures typically range from 49°F to 76°F and rarely go below 43°F or above 84°F. The annual average rainfall in the city is approximately 12 inches, with the majority occurring between December and March.3F
4 The average monthly wind speeds in the city
generally range from 5 miles per hour (mph) to 9 mph, with the highest wind speeds occurring along the coast and during the spring and summer months.4F
5 Winds in the city generally blow in a
southwest direction year-round, and tend to decrease in average speed moving inland. The city is

3 Climate is the average weather over a long period of time, such as 30 years, whereas weather is the hourly or daily state of the atmosphere at a given place with respect to heat, humidity, sunshine, wind, rain, etc. 4 NOAA National Weather Service; https://www.weather.gov/wrh/Climate?wfo=lox, accessed December 2022. 5 Wind and weather statistics for Santa Monica Pier and Santa Monica Airport from Windfinder.com, accessed in 2022.

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bounded by the Pacific Ocean to the west and as a result, experiences a marine microclimate. For additional information on the climate in Santa Monica please also refer to Section 2.

Climate change projections and the impacts that climate change will have on the weather of the southern California region, including Santa Monica, are forecasts and as such have inherent uncertainties. Computer models that attempt to predict future weather patterns are based on complex data that are in a state of flux. Essentially, climate change is driven by greenhouse gas (GHG) emissions and changes in the level of emissions released into the atmosphere in the near term versus the distant future will play a role in determining the severity of potential future climate change effects. These uncertainties in GHG emissions depend in part on factors such as population levels, economic activities, government policies, and personal behavior. Climate change models also consider factors such as water vapor, carbon dioxide, heat, and the Earth’s rotation to calculate the interactions between the ocean, the atmosphere and land. The models are currently limited by the availability of climate data and computing power; as these factors improve, models are expected to improve, yielding higher-resolution results in less time, and better forecasts.5F 6 The climate change projections presented in the following sub-sections are based on greenhouse gas concentration trajectories called Representative Concentration Pathways (RCPs) adopted by the Intergovernmental Panel on Climate Change (IPCC, 2022a). Representative concentration pathways are different scenarios for the future severity of climate change. Four scenarios are commonly used by the global scientific community: RCP 2.6, RCP 4.5, RCP 6, and RCP 8.5.6F 7 The higher the RCP
number, the more severe future climate change conditions are projected to be. Each RCP is briefly described below.
• RCP 2.6 – Stringent Mitigation/Low Emissions Scenario: This scenario represents aggressive emissions reduction that assumes global greenhouse gas emissions will peak in 2020, with emissions of carbon dioxide (CO2) from human activities reducing to zero around 2075. RCP

2.6 most closely corresponds to the ambitious goals of the United Nations Framework Convention on Climate Change 2015 Paris Agreement. The RCP 2.6 pathway delivers a temperature increase of about 1.6˚C by 2100, relative to pre-industrial temperatures. • RCP 4.5 and RCP 6.0 – Intermediate/Medium Emissions Scenarios: These scenarios represent a mitigation scenario where global greenhouse gas emissions peak by 2040 and 2060, respectively, then decrease for the rest of the century. The RCP 4.5 and 6.0 pathways lead to temperature increases of about 2.45˚C and 2.85˚C, respectively, by 2100, relative to pre-industrial temperatures.
• RCP 8.5 – High Emissions Scenario: This scenario represents a “business-as-usual” scenario where global greenhouse gas emissions continue to rise throughout the 21st century. The RCP 8.5 pathway leads to a temperature increase of about 4.3˚C relative to pre-industrial temperatures by the year 2100. The California Office of Planning and Research (OPR) recommends that agencies use RCP 8.5, the high emissions scenario, when considering impacts through 2050 because there are minimal differences between the low and high emissions scenarios through the first half of the century.

6 For a more in-depth discussion on climate models, refer to https://www.climatehubs.usda.gov/hubs/northwest/topic/basics-global-climate-models. 7 The RCP numbers (2.6, 4.5…8.5) refer to the range of radiative forcing values in the year 2100 that affect global warming and climate change. Radiative forcing is the change in the net radiative flux [energy measured in watts per square meter (W m− 2)] at the tropopause or top of atmosphere due to a change in an external driver of climate change such as a change in the concentration of carbon dioxide or changes in solar energy output.

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Vulnerabilities to climate change are also dependent on a variety of geographic, social, economic and governmental factors. As a result, every community is likely to have a different response to the effects of climate change. Climate change vulnerability is defined by the IPCC as the susceptibility of a population, system, or resource to the negative effects of climate change and other stressors, and includes three components: exposure, sensitivity, and adaptive capacity. Each of these components is defined below:
• Exposure is the amount and rate of change that a population or system experiences from the direct (e.g., temperature, precipitation changes) or indirect (e.g., habitat shifts due to changing vegetation composition) impacts of climate change; • Sensitivity refers to characteristics of a population or system that are dependent on specific environmental conditions, and the degree to which it will likely be affected by climate change (e.g., temperature or hydrological requirements); and • Adaptive capacity is the ability of a species (including humans) to cope and persist under changing conditions through local or regional acclimation, dispersal or migration, adaptation (e.g., behavioral shifts), and/or evolution.

Findings regarding Santa Monica’s vulnerability to climate-related hazards, as described in this report, are based on a review and consolidation of the vulnerability and risk assessments obtained from a variety of governmental resources and web-based tools, including data obtained from the Federal Emergency Management Agency (FEMA) and other Federal organizations, the State of California, Los Angeles County, and the City of Santa Monica. Some of these sources provide information and rankings specific to Santa Monica’s vulnerabilities to climate change, and natural hazards in general, whereas other sources provide a regional, County-specific assessment but do not zero-in to a city or census-tract level of detail.

EXTREME HEAT
Extreme heat occurs when temperatures rise significantly above the average high for a particular region. Therefore, “extreme heat” is a relative term—temperatures of 100 degrees are normal in locations like the Coachella Valley, but almost unprecedented in coastal regions of Los Angeles County. The coastal regions in Los Angeles County (LA County) historically experience 95thpercentile daily maximum temperatures of about 85°F, while inland regions historically experience 95th-percentile daily maximum temperatures of about 100°F.7F 8 The two highest recorded
temperatures to date in Santa Monica were 103°F, recorded on September 27th, 2010, and 101°F, recorded on September 4, 2022 and on October 24, 2017. Comparatively, in the inland San Fernando Valley a notable heat event occurred in September 2020, where maximum temperatures spiked to an all-time high of 121°F. It is also worth mentioning that many of the record-high monthly temperatures in Santa Monica occurred within the past 15 years (Table 11-2).

8 Los Angeles County (2021), LA County Climate Vulnerability Assessment.

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Table 11-2: Record Monthly Temperatures (°F) and Years of Record in Santa Monica Temp Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual High 88
2018
90 2022
94 2015
95 2009
94 2014
92 1957
92 2018
95 1983
103
2010
101
2017
100
1966
89 1979
103
2010
Low 26
1913
32 1903
28 1907
33 1917
39 1915
41 1908
42 1906
47 1919
40 1907
37 1919
32 1919
30 1916
26 1913
Based on data recorded between 1900 and 2023 as follows: 1900-1938, Santa Monica weather station near the intersection of 11th Street and Olympic Boulevard; 1939-2000, Santa Monica Pier; 2001-2023, Santa Monica Municipal Airport.

Source: https://www.extremeweatherwatch.com/cities/santa-monica, with data from the NOAA National Climate Data Center accessed on September 1, 2023.

An extreme heat event is defined as two or more days and nights of unusually high heat for the region. An extreme heat day is defined as a day in a year when the daily maximum exceeds the 98th historical percentile value of historical daily maximum temperatures, based on data from 1961 to 1990, between April and October. In Santa Monica, annual temperatures typically range from 49°F to 76°F and are rarely below 43°F or above 84°F.8F
9 If the maximum temperature in Santa Monica is
greater than 86.7°F, that day is considered an extreme heat day in the city.

Between 1961 and 1990, the observed historical data for the city indicates an average of two (2) extreme heat days per year, with some years experiencing zero extreme heat days, and others seeing more than the average. In September 2022, Santa Monica experienced a heat wave, with temperatures ranging between 87°F and 101°F, that lasted nine (9) consecutive days.9F 10 In 2024,
between September 5th and September 9th, the city hit highs of at least 87°F that prompted an excessive heat warning. A high of 100°F was recorded on September 6th; this temperature has only been recorded in Santa Monica eight times in its recorded history.10F 11 Looking forward in time, extreme heat is predicted to intensify in Santa Monica. While the historical 30-year annual average maximum temperature in Santa Monica is 69.1°F11F 12, under the worst-case
climate change scenario (RCP 8.5), Santa Monica is projected to experience an annual average maximum temperature increase of 3.7°F (to 72.8°F) by mid-century (2035-2064), and a 6.8°F increase (to 75.9°F) by end-century (2070-2099). In contrast, the medium emission scenario (RCP

4.5) projects an average maximum temperature increase of 2.9°F (to 72°F) by mid-century, and 3.9°F (to 73°F) by end-century (Figure 11-3, upper panel).

9 Weather Spark, Climate and Average Weather Year-Round in Santa Monica; https://weatherspark.com/y/1727/Average-Weather-in-Santa-Monica-California-United-States-Year-Round, accessed in December 2022. 10 https://www.extremeweatherwatch.com/cities/santa-monica/year-2022. 11 https://smdp.com/2024/09/12/heat-wave-dying-down-after-rare-100-degree-high/, accessed on September 16, 2024. 12 Cal-Adapt Local Climate Change Snapshot for Santa Monica California, cal-adapt.org.

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Figure 11-3: Projections of Maximum Temperatures and Extreme Heat Days in Santa Monica (1950-2100) under RCP 4.5 (teal) and 8.5 (violet) Source: Cal-Adapt Local Climate Change Snapshot for Santa Monica California. cal-adapt.org.

Similarly, the annual number of extreme heat days in Santa Monica is also projected to increase (Figure 11-3, lower panel). Compared to the historical average of two (2) extreme heat days per year, the city’s extreme heat days are projected to increase to an average of eight (8) days per year by mid-century (2035-2064), and an average of 21 days per year by end-century (2070-2100) under the RCP 8.5 scenario. Compared to the RCP 8.5 scenario, the RCP 4.5 scenario is projected to result in an average of seven (7) extreme heat days by mid-century and an average of nine (9) extreme heat days by the end of the century. These numbers highlight the importance of managing GHG emissions, as the number of extreme heat days by end-century is projected to increase at a significantly higher rate under the RCP 8.5 scenario compared to the RCP 4.5 scenario.

It is also important to note the spatial differences in global warming in southern California (California’s Fourth Climate Change Assessment). Specifically, coastal regions are projected to experience relatively lower amounts of warming due to the ocean’s buffering effect, while interior regions are expected to experience the highest amounts of warming, up to 10°F in the late 21st century under RCP 8.5 (Hall et al., 2018).

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Social Vulnerability to Extreme Heat
Extreme heat is dangerous to all living creatures on Earth. For human populations, direct exposure to extreme heat can cause heat cramps, heat exhaustion, heat stroke, and quicken dehydration.

Extreme heat is the leading cause of weather-related deaths in the United States and in California, as discussed previously. Hot and sunny days can also increase the production of ground-level ozone, a harmful pollutant that is the main component of smog, which can damage the respiratory system and is particularly harmful for those with asthma and other respiratory conditions.

Abnormally high temperatures can also harm non-human animals and plants that are not adapted to these conditions, increase wildfire conditions by drying out plant material, and contribute to drought conditions. Thus, extreme heat can also indirectly affect humans by causing wildfires, limiting water, and affecting food production. Specifically, extreme heat directly impacts crops due to intense ultraviolet light, which can stress the plants, resulting in stunted development and plant mortality. This in turn causes lower quality produce, and overall reduced crop yields with significant implications for food security (see the sub-section on drought below).

Heat waves, which are extended periods of extreme temperatures, can be particularly dangerous by exacerbating drought and wildfires, and compromising air quality. Extreme heat also increases electricity demand for cooling, and can simultaneously lower the ability of transmission lines to carry power, possibly leading to electricity reliability issues like rolling blackouts during heat waves.

For example, about 15,200 electricity customers in the Los Angeles areas of Lincoln Heights and Highland Park were without power at the height of the heat wave in September 2024.12F 13 Like many other effects of climate change, the adverse impacts of extreme heat are felt most acutely by vulnerable populations, including older adults, children, and those with pre-existing health conditions such as asthma and cardiovascular disease. Combining these characteristics with additional factors, such as poverty, occupation (outdoor workers), language barriers and housing insecurity, can put these individuals at a disproportionately high risk of heat-related illness and death (Basu and Malig, 2011). Unhoused populations, those with inadequate shelter, or those without access to air conditioning, are particularly vulnerable to life-threatening heat.

In its heat wave planning and response activities, the City of Santa Monica utilizes the National Weather Services HeatRisk tool to better identify when forecast conditions pose heat-related risks to heat-sensitive populations or the general public. HeatRisk is an experimental tool that combines Centers for Disease Control and Prevention’s (CDC) health-based temperature thresholds with National Weather Service’s local temperature parameters and climatology. HeatRisk takes into consideration how unusual the heat is for the time of year, the duration of the heat wave (both daytime and nighttime temperatures are considered), and if the temperatures pose an elevated risk of heat-related impacts based on CDC data.

The California Heat Assessment Tool (CHAT) was developed to help state and local public health officials understand how heat vulnerability will change with increasing temperatures due to climate change. Development of the tool was funded by the California Natural Resources Agency as part of development of the state's Fourth Climate Change Assessment. The tool helps users identify heat vulnerable areas based upon changes in high heat days under different climate scenarios and social, health and environmental vulnerability factors. The study defines "Heat Health Events" (HHEs) as

13 https://smdp.com/2024/09/12/heat-wave-dying-down-after-rare-100-degree-high/, accessed on September 16, 2024.

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heat events that cause negative public health impacts. The tool helps users determine how climate change will affect the severity, duration, and shifts in timing of HHEs under different emissions scenarios. Projected HHEs for Santa Monica through the year 2090 using CHAT are presented in Table 11-3 below.

Table 11-3: Santa Monica Projected Heat Health Eventsβ
Time Period
2011-2030 2031-2050 2051-2070 2071-2090
Annual Number of Heat Health
EventsΩ 2.2 4.45 6.25 6.75
Average Max Temperature (˚F) 84.46 83.58 83.45 83.05
Average Min Temperature (˚F) 68.92 69.59 70.12 69.85
Average Event Duration 3.77 4.37 4.88 5.25
Average Max Relative Humidity (%) 83.09 82.26 80.69 84.03 Average Min Relative Humidity (%) 45.39 46.81 47.34 50.08 Annual Frequency Relative Change
(%) 127.59 360.34 546.55 598.28
Duration Relative Change (%) 35.07 56.49 74.72 88.03
β Data represent RCP 8.5, the months of June, July, and August; and the 95th percentile. Ω Heat Health Event (HHE) is any event that results in negative public health impacts, regardless of the absolute temperature. Each local area has a unique HHE specific to its climate and the historical sensitivity of people in that area to past heat events.

Source: California Heat Assessment Tool, 2024.

The primary indicators of social sensitivity and lower adaptive capacity to extreme heat in Los Angeles County are higher percentages of children and older adults, pre-existing health conditions such as asthma and cardiovascular disease, outdoor workplace conditions, no health insurance, mobile homes/homes that lack adequate thermal envelopes, households without vehicle access or transit access, and low-income households.

Santa Monica’s social vulnerability to extreme heat is considered low according to the Los Angeles County Climate Vulnerability Assessment (LACCVA, Los Angeles County, 2021), and is projected to be one of the lowest in the County under RCP 8.5 conditions mid-century. This is primarily due to the City’s low overall social sensitivity score, meaning the general population is less susceptible to the negative impacts of extreme heat events. Nevertheless, there are vulnerable populations within the city, such as older adults and people with health conditions, unhoused individuals, households without air conditioning, and households without access to vehicle access, that should be considered when developing climate-hazard mitigation goals and policies. The lower overall temperatures in Santa Monica during a regional heat wave as a result of its geographic location are also expected to result in an increase in day-time visitors, with inland residents flocking to the beach to cool off. This will result in extra strain on traffic patterns and would impact access by the local residents to the same limited resources being utilized by a larger number of people.

The impacts of extreme heat on utility infrastructure can result in significant damage, repair costs, and service interruptions that can be catastrophic to human health. Some types of infrastructure, including power lines and roadways, face greater stresses during high temperatures, as the heat makes the materials used to build these structures unstable, which in turn makes failure more likely.

The 2019 Santa Monica Climate Action and Adaptation Plan (CAAP) ranks the City’s water and Natural Hazard Mitigation Plan Section 11
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Based on the LACCVA and CAAP vulnerability assessments, the following bullet points summarize the primary issues Santa Monica is likely to face due to extreme heat and rising temperatures. Note that extreme heat can also exacerbate drought and wildfire conditions; those hazards and their potential impacts on the city of Santa Monica are discussed separately in this report (drought is discussed in this section and wildfires are discussed in Section 10). • Impacts to the health of vulnerable populations, including the elderly, children, homeless, and those with chronic illnesses
• Impacts to the health and safety of workers, especially for those working outdoors for long hours
• Power outages during extreme heat events due to regional energy supply-demand imbalances
• Reduced water supply and quality regionally
• Uncomfortable and potentially unsafe conditions for occupants of buildings without air conditioning
• Inadequate power for cooling equipment at residential care, continuing care and nursing facilities
• Instability and potential failure of critical infrastructure, including power lines and roadways • Faster wear and tear of pavement, increasing safety hazards and maintenance costs Extreme Heat Mitigation Actions and Resources
There are a variety of policies and action items that communities can undertake to reduce the impacts of extreme heat on their population and infrastructure. The City of Santa Monica, in its 2019 CAAP, has identified and is already undertaking several action items designed to do this.

First and foremost, California and Santa Monica have both undertaken an aggressive plan to reduce GHG emissions. The City’s goal is to reduce GHG emissions by 80% below 1990 levels by 2030.

As of 2022, Santa Monica had achieved a 48% reduction in emissions from 1990 levels, with vehicle transportation and building electricity usage showing the largest decreases in carbon emissions.13F 14 To reach its goals, the City has implemented and will continue to implement a series of programs, initiatives and strategies. These programs currently include: 1) reducing the use of fossil fuels to heat and cook in residential and commercial buildings, and 2) increasing the use of electric vehicles (EVs). As part of this last effort, the City has adopted a new code requiring new multi-family buildings to provide a larger number of EV charging stations. The City will also restrict the sale of gasoline cars by 2035.

Other actions aimed specifically at managing extreme heat events include identifying suitable locations for neighborhood resilience hubs and cooling centers at City-owned and non-City-owned sites from where disaster assistance and supplies can be made available to impacted individuals14F

15. 14 https://www.santamonica.gov/blog/sustainable-and-connected-community-the-2022-santa-monica-greenhousegas-emissions-inventory; accessed June 17, 2024. 15 Climate-Ready Community Action Items 2 (Expand the Community Resilience Network) and 4 (Prepare for Extreme Heat) in Santa Monica’s 2019 CAAP.

Natural Hazard Mitigation Plan Section 11
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2025 Climate Change & Severe Weather Hazards Page 11-11 For example, during the most recent heat wave in September 2024, City of Santa Monica airconditioned libraries and park facilities were opened for multiple days to provide relief from the heat, and City staff highlighted heat-related health information and the availability of pools and splash pads at Annenberg Community Beach House, Santa Monica Swim Center, Virginia Avenue Park and Tongva Park. City personnel distributed emergency water at these cooling locations, especially for those seeking relief from the heat, including unhoused populations and seniors. The City and County of Los Angeles also opened several cooling centers.15F 16 City departments closely
monitored heat conditions and distributed heat safety information to its many outdoor workers.

Given the long-term impacts of climate change, the City is also considering programs to prepare residents to respond to climate change. This includes continuing the development of community outreach and engagement materials. Currently the City provides general information about extreme heat safety on one of several emergency preparedness websites with links to general resources, including the National Integrated Heat Health Information System. Other action items that the City may consider deploying during heat waves include ensuring that temporary shade structures are available for community events, that coastal access is maintained for those seeking relief from the heat, and that City facilities have the capacity to provide air conditioning for residents, visitors and workers.

Other long-term action items listed in the City’s CAAP (2019) include adopting standards for asphalt and roof surfaces that will help reduce the local heat-island effect; develop outreach and educational materials on passive cooling strategies such as shade trees and insulation; and increase tree canopy in vulnerable neighborhoods. The City is also promoting fossil-fuel-free HVAC systems, such as pump technologies, for buildings installing or replacing air conditioners16F

17. Longer-term action items
include developing building design guidelines for climate-resilient buildings, and adopting and implementing these standards for new and substantially renovated buildings17F

18. The City of Santa Monica is also partnering with local utilities, regional agencies and local jurisdictions to assess the vulnerability of its energy infrastructure. Other action items include the deployment of local resilient energy systems, including solar, energy storage, combined heat and power, and fuel cells for new projects and existing facilities. These actions are meant to prepare the community for the impacts of future heat waves, wildfires, and other similar hazards. Residents and local businesses are also encouraged to install resilient energy systems18F

19. In addition to the reports referenced above, other publicly available resources and planning tools include:
• California 2022 Extreme Heat Action Plan: Outlines California's all-of-government approach to mitigating the health, economic, cultural, ecological, and social impacts of increasing average temperatures and heat waves.
• 2019 Our County: Los Angeles County Sustainability Plan: A regional plan that outlines what local governments and stakeholders can do to enhance the well-being of every

16 https://smdp.com/2024/09/12/heat-wave-dying-down-after-rare-100-degree-high/, accessed September 16, 2024. 17 Climate-Ready Community Action Item 4 (Prepare for Extreme Heat) in Santa Monica’s 2019 CAAP. 18 Climate-Ready Community Action Item 6 (Climate Resilient Building Design Standards) in Santa Monica’s 2019 CAAP. 19 Climate-Ready Community Action Item 7 (Increase Resilience of Local Energy Infrastructure) in Santa Monica’s 2019 CAAP.

Natural Hazard Mitigation Plan Section 11
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2025 Climate Change & Severe Weather Hazards Page 11-12 community in the County while reducing damage to the natural environment and adapting to the changing climate.
• The Center for Disease Control and Prevention (CDC): General information on how to prepare for and avoid impacts of extreme heat.
• 2018 California’s Fourth Climate Change Assessment (CA Fourth Assessment): Provides information to build resilience to climate impacts in California, including temperature, wildfire, water, sea level rise, and governance. The Fourth Assessment includes reports for nine regions of the state. Each of these reports provides a summary of relevant climate impacts and adaptation solutions for a region of the state. The Los Angeles Regional report (Hall et al., 2018) was referenced for this analysis and provides an overview of climaterelated risks and adaptation strategies specific to this region. • Cal-Adapt: A web-based data and visualization tools for key climate variables. Originally released in 2011, the current version of Cal-Adapt (version 2.0) was developed and launched as part of California’s Fourth Climate Change Assessment. • Climate Mapping for Resilience and Adaptation (CMRA): A web-based assessment tool that provides projections on climate change for the next several decades at the census-tract level, and its impacts on community assets. Provides information on exposure to five common climate-related hazards–extreme heat, drought, wildfire, flooding and coastal inundation. • Climate Risk & Resilience Portal (ClimRR): Developed by the Center for Climate Resilience and Decision Science at Argonne National Laboratory in cooperation with AT&T and the Federal Emergency Management Agency (FEMA), this web-based tool provides peerreviewed climate datasets that can be used to run simulations of future climate conditions in support of decision-making and adaptation efforts.

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2025 Climate Change & Severe Weather Hazards Page 11-13

DROUGHT
Droughts are prolonged periods of abnormally
low rainfall that can lead to shortages in water
supply, increased risk of wildfires, higher volumes
of dust, and damage to habitats and vegetation.

Other climatic characteristics such as high
temperature, high wind, and low relative humidity
contribute to drought conditions.

Drought severity can be measured by factors
including the drought’s duration, intensity, and
geographic extent, as well as regional water supply
demands by humans and vegetation, making it
difficult to conduct comprehensive risk
assessments. The U.S. Drought Monitor (USDM) is
a map released every week showing which areas of
the United States are being impacted by drought,
and how severe is the drought. The system used
includes five categories and colors ranging from
yellow (abnormally dry) to dark red (exceptional
drought) to illustrate the severity of the drought in
different areas. Areas with normal or wet conditions
are shown in white.

Figure 11-4 shows the five-category system of
drought severity and the percentage of California
under each drought stage in 2022.19F
20 Criteria used
to assign an area onto one or other category are also
provided. For example, abnormally dry years have
increased and earlier irrigation needs, whereas
areas in exceptional drought have fallowed land or extremely low agricultural yields.

Southern California is prone to periods of extremely dry conditions due to historically warm temperatures, dry soils, precipitation deficits, and low snowpack in the Sierra Nevada Mountain Ranges. Between 2012 and 2021, California experienced two historic droughts resulting in widespread agricultural, ecological, and wildfire-related impacts (Huang and Swain, 2022). In early 2023, however, intense precipitation as a result of a series of atmospheric rivers, eased the state’s drought concerns. The 2023 wet winter was followed later in the year by rain brought by Tropical Storm Hilary, and in the first week of February 2024, another strong storm system brought additional flooding rains to southern California (see Section 8). The variations in drought conditions in Los Angeles County between January 2000 and September 2024 are shown on Figure 11-5. The County was in some form of drought for 14 of the last 24 years. More than 80% of the County was in an “exceptional drought” (D4) from 2014 to 2017 and about 20% of the County was in a D4 drought in 2021 and 2022. Note that in 2023 and 2024 Los Angeles County is shown as not in a drought condition after California experienced heavy rains due to several atmospheric rivers in late 2022 and early 2023 (see Section 8 for more information on atmospheric rivers).

20 National Integrated Drought Information System: https://www.drought.gov/historicalinformation?dataset=0&selectedDateUSDM=20240910 Figure 11-4: 2022 California Drought,
Five-Category System
Natural Hazard Mitigation Plan Section 11
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2025 Climate Change & Severe Weather Hazards Page 11-14 Figure 11-5:

Percent Area of Los Angeles County in U.S. Drought Monitor Categories: 2000-2024 Source: U.S. Drought Monitor: https://droughtmonitor.unl.edu/DmData/TimeSeries.aspx, accessed September 17, 2024 While droughts are a natural phenomenon, anthropogenic (human-caused) warming has increased the probability that low-precipitation years coincide with warm years, increasing the risk and severity of droughts and low snowpack across the state. It is estimated that human-caused climate change accounts for 19% of drought severity and 42% of the soil moisture deficit in California since 2000.20F
21 Moreover, climate change is expected to continue to cause wide variability in precipitation levels, with significant fluctuations between wet years and dry years. Climate models predict with more than an 80% probability that the southwestern United States will experience a multidecadal drought during 2050-2099 under the RCP 8.5 scenario (Huang and Swain, 2022). Statewide projections for precipitation show fewer wet days, wetter winters, drier springs and autumns, and an increase in dry years as well as maximum precipitation in a single day (Pierce et al., 2018).

Social Vulnerability to Drought
During dry years, the resulting loss of snowpack in the Sierra Nevada and other mountainous regions in the southern California region will mean less water for agriculture, urban users, and utilities.

Critical vulnerabilities associated with drought include a reduction in the availability of clean and affordable drinking water, fallowing of agricultural lands (which would impact the region, including Santa Monica, indirectly in the form of limited food availability and higher food prices), regional impacts to power generation that lead to higher utility costs, increased wildfire risk, and the increasing prevalence of certain diseases caused by the inhalation of dust spores, such as Valley fever (Gorris et al., 2019).

Some of the impacts on natural resources and infrastructure systems, with an emphasis on how these resources and systems are anticipated to directly and indirectly impact the residents of Santa Monica and nearby communities are described further below:

21 California Air Resources Board, 2022, 2022 Scoping Plan for Achieving Carbon Neutrality; available at https://ww2.arb.ca.gov/sites/default/files/2023-04/2022-sp.pdf Natural Hazard Mitigation Plan Section 11
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2025 Climate Change & Severe Weather Hazards Page 11-15 • Active water wells: droughts cause a decline in the regional groundwater table as the regional aquifers are not replenished by infiltration of rainwater. If the groundwater table drops below the effective pumping depth of the water wells, the wells become dry. This in turn would severely impact the City’s efforts to become water self-sufficient. • Aqueducts and water distribution: drought-induced subsidence damages the aqueduct system that supports the agricultural fields in the San Joaquin and Coachella valleys. This damage, combined with reduced water supplied to the farmers, could cause the collapse of the agricultural sector in California. This would have State-wide implications, with losses in the billions of dollars21F

22. Considering that California produces most of the nuts and fruits and some of the vegetables grown in the United States, the consequences of drought would have a significant impact on food security locally and throughout the country. • Groundwater recharge basins and spreading grounds: drought causes recharge basins and spreading grounds to dry up, which in turn results in increased pumping of groundwater. In the short term, increased pumping raises energy consumption and thus energy bills; in the long term, it lower groundwater levels and causes water wells to go dry, as discussed in the active water wells bullet above. Lower groundwater levels pose a threat to water security, and causes land subsidence and degradation of groundwater quality due to infiltration and mixing with saline water.
• Lakes, reservoirs and rivers: dropping water levels in dams and reservoirs translates into reduced water resources (i.e., increased water shortages), and reduced hydroelectric power generation. Given that Santa Monica relies primarily on clean, green (wind, solar, geothermal and hydroelectric) energy for most of its electric power, the drop in reservoir water levels is likely to have only a minimal impact on the City’s energy supplies. However, with a reduction in groundwater levels and urban runoff, the City may have to augment its water needs by relying again, at least in part, on imported water. Diminished water supply due to lower water levels in lakes, rivers, and reservoirs would be felt regionally and locally, with the limited supply driving the cost for water agencies and, ultimately, consumers. • Water treatment plants: drought would severely reduce the flow of urban runoff that Santa Monica is increasingly using to meet its water demand needs. Reduced flows to the City’s wastewater plants could damage the equipment, increase costs, and impact the City’s ability to comply with water treatment standards.
• Parks, open space and gardens: droughts directly impact the heath and quality of natural landscapes. This in turn impacts the health of native plant and animal species, expands the populations of bark beetles and other pests, increases the risk of wildland fire in the northern portion of Santa Monica and adjacent areas to the north, reduces the availability of green space and recreation areas, and reduces the production of fruits and vegetables in local backyard and community gardens.

Drought Planning and Mitigation Actions
Although drought cannot be controlled, drought can be managed through drought planning and in community-level, day-to-day management decisions while the drought is taking place. The Governor of California, for example, signed an executive order in April 2019 directing specific State agencies to develop a Water Resilience Portfolio to “ensure safe and dependable water supplies, flood protection and healthy waterways for the state’s communities, economy and environment.” The portfolio includes 142 separate actions to support local efforts to maintain and diversify water

22 https://www.ppic.org/publication/policy-brief-drought-and-californias-agriculture/, accessed October 2023.

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2025 Climate Change & Severe Weather Hazards Page 11-16 supplies, protect, and enhance natural systems, and prepare for future risks. Key actions include continued implementation of the Safe and Affordable Drinking Water Act of 2019, the Sustainable Groundwater Management Act of 2014, and the 2018 package of water-use efficiency laws known as the “make conservation a way of life” laws (Executive Order B-37-16). In 2017, the City of Santa Monica also passed the Water Neutrality Ordinance which limits new water demands for new construction projects. Fees paid in-lieu of reducing water demand onsite are used for water efficiency projects elsewhere in the community. Santa Monica also offers resources for property owners to convert to drought tolerant landscaping and irrigation and install rainwater harvesting systems.

In 2021, Santa Monica issued its 2020 Urban Water Management Plan (UWMP) that includes Water Service Reliability and Drought Risk Assessments (DRA). The 2020 DRA assessed the city’s water supply reliability under drought conditions for the years 2021 to 2025 and concluded that if projected imported and local supplies are developed or maintained as forecasted, no water shortages are anticipated in the City’s service area during the 20-year planning period.22F 23 The UWMP also
includes a Water Shortage Contingency Plan (WSCP) which serves as an action plan for the City during an actual or predicted drought or catastrophic water supply shortage. More recently, in April 2023, the City issued a (Draft) 2023 Annual Shortage Assessment Report, which evaluates water supply reliability in the city for the period between July 1, 2023 and June 30, 2024. That study found that if unconstrained demand conditions prevailed, and assuming worst-case drought conditions and a decrease in groundwater availability due to construction at the City’s Arcadia water treatment plant, water demand would likely exceed supply (a demand of 13,661 acre-feet in demand vs. a supply of 13,609 acre-feet). To manage this anticipated shortage, the study authors recommended that the City rely on water use restrictions consistent with the State-defined Water Shortage Stage 2 that aim for a City-wide water use reduction of 20% compared to the 2013 water use levels used as a baseline.

The City relies primarily on two sources of potable water: (1) groundwater extracted by the City from the Santa Monica Groundwater Basin (SMGB), and (2) water supplied by the Metropolitan Water District (MWD) that is imported from northern California and the Colorado River. Groundwater accounts for between about 35 and 75% of the total water used, with the percentage varying on a year-by-year basis based on a variety of factors typically related to the operational status of the groundwater wells and water treatment plants that supply Santa Monica. In 2018, Santa Monica had set out to become independent of imported water by 2023. Although, as of this writing, this goal has not been achieved, the City has several ongoing projects that are part its Sustainable Water Infrastructure Project (SWIP) designed to conserve groundwater, reduce wastewater, and improve beach water quality.

The SWIP is comprised of the following elements, as outlined in the 2019 CAAP:
• Element 1 provides for a modular reverse osmosis unit at the existing Santa Monica Urban Runoff Recycling Facility (SMURRF) located near the Santa Monica Pier. The reverse osmosis-upgraded SMURRF will also leverage the recently completed Clean Beaches Initiative Project by treating stormwater and brackish groundwater for reuse. • Element 2 provides for a new underground Advanced Water Treatment Facility (AWTF) capable of treating up to 1 million gallons of wastewater per day, as well as stormwater for

23 City of Santa Monica, 2021, 2020 Urban Water Management Plan, dated June 2021.

Natural Hazard Mitigation Plan Section 11
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2025 Climate Change & Severe Weather Hazards Page 11-17 immediate non-potable reuse. The advanced treated water will be used for groundwater recharge.
• Element 3 provides for the installation of a 1.5 MG underground stormwater harvest tank plumbed directly to the AWTF beneath the Civic Auditorium parking lot.

Other action items recommended in the 2019 CAAP that the City has implemented or is in the process of implementing include expanding capacity at the Arcadia Water Treatment Plant to accommodate more water, and increasing water production efficiencies at the plant by recovering brine concentrate. The CAAP also recommends the restoration of the Olympic wellfield and developing a new groundwater well to enhance the City’s resilience to drought.23F 24 The 2019 CAAP
set forth actions to achieve water self-sufficiency to combat the unavoidable and growing threats of climate change-driven drought impacts. Actions in the CAAP address water conservation measures in the commercial and residential sectors, alternative water supply, and local groundwater production. However, as discussed above, an extensive drought period that results in a significant drop in groundwater levels and a reduction in storm runoff could severely impact the City’s efforts to become water self-reliant. Thus, actions listed in the 2019 CAAP should be reviewed on a regular basis to ensure that they are still relevant given any changed conditions.

SEA-LEVEL RISE
Sea-level rise is the increase in the ocean’s surface height due to the melting of glaciers and sea ice as well as the thermal expansion of sea water at high temperatures. Changes in sea-level have occurred throughout the Earth’s history and typically over many thousands of years. This section discusses contemporary and near-future sea-level rise as a result of human-driven changes in climate and specifically global warming.

Sea-level rise over the past several decades has been relatively gradual. In the Los Angeles region, sea-level increased 0.39 inches per decade from 1924 through 2017 (Hall et al., 2018, based on data from NOAA). A more recent analysis suggests that the sea level trend for Los Angeles is 0.42 (±0.08) inches per decade for the time period between 1923 and 2023, which amounts to a sea level rise of approximately 4.2 inches for the century.24F 25 Although these numbers do not seem
significant, coastal communities, including many along California, are already experiencing the effects of global climate change in the form of more frequent storm flooding, and increased cliff, bluff and shoreline erosion.

Worldwide, including along the California coastline, the rise in sea-level and storm surges is anticipated to lead to loss of coastal wetlands, erosion of cliffs and beaches, and saltwater contamination of drinking water. These conditions are in turn already impacting infrastructure (including transportation routes, harbors, wastewater treatment plants, and storm water systems), and flooding of low-lying residential and commercial properties. At a human level, the impact of sea-level rise on coastal communities can perhaps be appreciated by the fact that in 2019, it was estimated that nearly 700 million people worldwide were living at or near sea level (Oppenheimer et al., 2019), and this figure is only expected to increase. The 2019 estimate is more than twice the

24 Water Self-Sufficiency Action Items 2 (Arcadia Water Treatment Improvements) and 4 (Expand Local Water Resources) in Santa Monica’s 2019 CAAP. 25 https://tidesandcurrents.noaa.gov/sltrends/sltrends_station.shtml?id=9410660, accessed September 18, 2024.

Natural Hazard Mitigation Plan Section 11
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2025 Climate Change & Severe Weather Hazards Page 11-18 entire population of the United States in 2024. In California alone, the number of people living at or near sea level is estimated at 25 million people.

Although sea-level rise by itself does not cause substantial changes to the landforms along the coastline, several processes associated with sea-level rise can have dramatic effects on our environment. For example, a significant rise in sea level will inundate coastal wetlands and lowlands, and the increased surges and swells associated with the rise in sea level will accelerate coastal erosion and exacerbate coastal flooding, thereby threatening local structures and habitat.

The combined effects of sea-level rise, and the high tides and large waves brought on by storms, especially during El Niño events and atmospheric rivers, will, in the short-term, result in increased flooding of low-lying areas, and accelerated erosion of beaches and sea cliffs, including the sea bluffs along Pacific Palisades. Other potential related processes include higher water tables, increased sea-water intrusion into fresh-water aquifers, and increased salinity of rivers, bays, and aquifers. The California Coastal Commission (2021) has estimated that a sea-level rise of 4.6 feet will place hundreds of miles of transportation infrastructure in the State at peril of flooding, including sections of Pacific Coast Highway that connect to Santa Monica. Sea-level rise will also impact dozens of water treatment facilities and water distribution networks, not to mention the livelihood of millions of people that depend on California’s $44-billion ocean-based economy. As a result, the Coastal Commission25F
26, together with other State agencies, has developed guidelines designed to plan for, and mitigate or reduce the impacts of sea-level rise.

Sea-level Rise Projections in Santa Monica and Social Impacts Sea-level rise within Los Angeles County (and globally) is projected to accelerate through the 21st century largely as a result of the melting of the West Antarctic Ice Sheet due to increased global temperatures. The exact extent of near-future sea-level rise is not yet certain, however, due in part to uncertainty of how humans will curtail greenhouse gas emissions in the coming decades.

Therefore, to understand potential effects, scientists and practitioners use five sea-level rise scenarios, which represent a plausible range of future sea-level rise. These scenarios were developed by the State of California Sea-level Rise Guidance (California Ocean Protection Council, 2024) and developed from projections from the Intergovernmental Panel on Climate Change Sixth Assessment Report. The five scenarios are as follows:
• Low: The result of aggressive emissions reductions leading to very low future emissions; this scenario is on the lower bounding edge of plausibility. • Intermediate Low: A reasonable estimate of the lower bound of most likely sea-level rise in 2100 based on sea-level observations and current estimates of future warming. • Intermediate: A reasonable estimate of the upper bound of most likely sea-level rise in 2100 based on sea-level observations and current estimates of future warming. • Intermediate High: The result of intermediate-to-high future emissions and high warming; this scenario is heavily reflective of a world where rapid ice sheet loss processes contribute to sea-level rise.
• High: High future emissions and high warming with large potential contributions from rapid ice-sheet loss processes; given the reliance on sea-level contributions for processes in which there is currently low confidence in their understanding, a statement on the likelihood of reaching this scenario is not possible.

26 https://documents.coastal.ca.gov/assets/slr/SLR%20Guidance_Critical%20Infrastructure_12.6.2021.pdf Natural Hazard Mitigation Plan Section 11
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2025 Climate Change & Severe Weather Hazards Page 11-19 For local and regional land-use and community planning efforts and projects, the California SeaLevel Rise Guidance Council recommends evaluation of the Intermediate, Intermediate High, and High scenarios to inform appropriate sea-level rise planning and project decisions. These scenarios project that sea-levels in Santa Monica will rise between 0.7 and 1.2 feet by 2050 and 2.9 to 6.4 feet by 2100 (Table 11-4 and Figure 11-6). Beyond the year 2100, the range of possible rises in sea level becomes increasingly large and increasingly difficult to estimate due to uncertainties associated with the physical processes responsible for this, such as earlier-than-expected ice sheet loss.

Table 11-4 and -Figure 11-6: Projected Sea-Level Rise Scenarios for Santa Monica Year Low I-L I I-H High
2020 0.2 0.2 0.2 0.2 0.2
2030 0.3 0.3 0.4 0.4 0.4
2040 0.3 0.4 0.5 0.6 0.7
2050 0.4 0.6 0.7 0.9 1.2
2060 0.5 0.7 1.0 1.5 1.9
2070 0.6 0.9 1.3 2.1 2.8
2080 0.6 1.0 1.7 2.9 3.9
2090 0.7 1.2 2.3 3.7 5.2
2100 0.8 1.4 2.9 4.6 6.4
2110 0.8 1.6 3.6 5.5 7.7
2120 0.9 1.8 4.2 6.2 8.8
2130 0.9 1.9 4.7 6.8 9.7
2140 1.0 2.1 5.2 7.3 10.6
2150 1.1 2.3 5.7 7.9 11.5
I-L = Intermediate Low, I = Intermediate, I-H = Intermediate-High Source: State of California Sea-Level Rise Guidance: 2024 Science and Policy Update: California Sea Level Rise Science Task Force, California Ocean Protection Council, California Ocean Science Trust.

To gain a better understanding of what these projected sea-rise levels would have on the Santa Monica coastline, an analysis was conducted using a sea-level rise visualization tool. The Coastal Storm Modeling System (CoSMoS) is a dynamic modeling tool developed by the United States Geological Survey and accessed through the Our Coast Our Future (OCOF) web interface. Its flooding layer allows users to select different values of sea-level rise (in meters and feet) and storm frequency (none [i.e., daily conditions], annual, 20-year, or 100-year) to visualize flooding at a 1- meter (~3-foot) resolution across California’s outer coast and estuaries. Because CoSMoS is a comprehensive modeling tool, it incorporates all the key drivers of coastal flooding, including sealevel rise, tides, seasonal effects, storm surge, waves, and river flows to produce location-specific maps showing total water levels and the associated flooding. It can be used as a screening tool to examine the flooding from different combinations of sea-level rise and storm conditions to help inform selection of the most appropriate sea-level rise and storm scenarios for a vulnerability assessment. Three sea-level rise scenarios were considered, with the results shown graphically on Figure 11-7.

The upper panel on Figure 11-7 shows the level of flooding projected using CoSMoS and a sea-level rise of 3.3 feet, which is approximately the increase in sea level expected by the year 2100 using the Intermediate scenario.26F
27 Flooding at this level under annual storm flooding conditions would

27 OCOF allows users to select from a limited number of sea-level rise values (i.e., 0.8, 1.6, 2.5, 3.3, 4.1, 4.9, 5.7,

6.6, 8.2, 9.8, and 16.4 feet). Depending on what water levels are identified for analysis, there might not be an option that is an exact match to the rise in sea level values presented in Table 11-4. For instance, the Intermediate Natural Hazard Mitigation Plan Section 11
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2025 Climate Change & Severe Weather Hazards Page 11-20 affect the entire sandy beach area along the coastline, the area around the Santa Monica Pier and the parking lots immediately adjacent to the pier, in addition to the area around the Pico Kenter storm drain outlet. This sea-level rise combined with a 100-year storm flooding event would result in flooding of the beach bike path near the northern portion of the city, the beach-front portion of several properties near and north of the Montana Avenue storm drain outlet, and the beach bike path and several of the parking areas south of the Pier and the Pico Kenter storm drain outlet. The lowermost two panels on Figure 11-7 show the same data for both the annual storm event and the 100-year storm event, with the flooded areas anticipated as a result of the Intermediate scenario shaded in light green.

The middle panel on Figure 11-7 shows the areas anticipated to regularly flood as a result of a rise in sea level of 4.9 feet based on the Intermediate-High scenario. Under this scenario, the flooding as a result of this rise in sea level combined with an annual storm is anticipated to impact a wider swath of the sandy beach area, in addition to the Santa Monica Pier area and surrounding parking lots, and a large swath of beach area between the bike path and Ocean Front Walk. This same sealevel rise level combined with a 100-year storm is projected to flood several of the properties on the west side of PCH near the north end of the city, and to nearly Appian Way, Ocean Avenue and Barnard Way on the southern half of the city. As before, these flood levels are also illustrated on the bottom two panels on Figure 11-7, with the Intermediate-High sea-level rise flooding levels shown in light blue.

Flooding levels associated with the High Scenario sea-level rise of 6.6 feet are shown on the third panel from the top on Figure 11-7. Annual storm flooding combined with this sea level is anticipated to reduce the width of the sandy beach area by approximately one-fourth of its current width, flood most of the area west of Appian Way, Ocean Avenue, and Barnard Way, and flood inland of the bike trail in the northern portion of the coastline. This rise in sea level combined with a 100-year storm is anticipated to flood past the east side of Barnard Way, Ocean Avenue and Appian Way on the southern half of the city, and flood most of the properties on the west side of PCH on the northern portion of the city. The flood limits associated with this High Scenario sea-level rise combined with an annual storm and a 100-year storm are shown on the bottom two panels in light purple.

scenario for Santa Monica at 2100 is 2.9 feet, which is between the available selections of 2.5 and 3.3 feet in OCOF. As indicated in the Guidance for these situations, it is not always necessary to analyze the exact numerical values; it is more important that the full range of values from Intermediate to High scenarios, with consideration of storm conditions, is evaluated.

Natural Hazard Mitigation Plan Section 11
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2025 Climate Change & Severe Weather Hazards Page 11-21 Figure 11-7: Flood Extent along the Santa Monica Coastline Through the Year 2100 Using Three Sea-Level Rise Scenarios Sources:

Esri, Airbus DS, USGS, NGA, NASA, CGIAR, N Robinson , NCEAS, NLS OS, NMA, Geodatastyrelsen, Rijkswaterstaat, GSA, Geoland, FEMA, Intermap and the GIS user community, County of Los Angeles, California State Parks, Esri, TomTom, Garmin, SafeGraph, GeoTechnologies, Inc., METI/NASA, USGS, Bureau of Land Management, EPA, NPS, US Census Bureau, USDA, USFWS.

Local Hazard Mitigation Plan Section 11
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2025 Climate Change & Severe Weather Hazards Page 11-22 Sea level rise in Santa Monica is anticipated to result not only in property damage and losses, as discussed above, but also disruption of schools, businesses, and transportation.27F 28 The Santa Monica
Pier, a major tourist destination and source of income for many, will be impacted by higher waves and a higher volume of water; both of these conditions can damage the structure. This has already happened: storm surges during the February 2022 storms caused an estimated $166,000.00 in damages, with most of that being damage to the Pier28F

29. As part of its AB 69129F30 assessment, the City
of Santa Monica has estimated that sea level rise will cost the City millions of dollars in losses to City infrastructure and in non-market value associated with the public’s use of the beach and other coastal resources. These costs are summarized in Table 11-5 below.

Table 11-5: Anticipated Costs of Sea Level Rise in
Santa Monica (in millions of $) Through the Year 2100
Year (Sea-level rise in inches) 2030 (11.8) 2050 (24) 2100 (65.7) Assets at risk or
Repair and replacement costs
$2.6 $2.7 $8.4
(plus $22.72 in losses
to private property)
Losses in non-market value $74.1 $260.8 $816.4
Cost of adaptation $2.7 - $186.9 $2.7 - $195.7 $28.9 - $204.5 Source: https://slcprdwordpressstorage.blob.core.windows.net/wordpressdata/2022/09/ab691-summarysantamonica.pdf Sea-Level Rise Adaptation Strategies in Santa Monica
In an effort to counteract some of the impacts discussed above, the City of Santa Monica has adopted a Local Coastal Program Land Use Plan (LCP LUP) that establishes policies and adaptation strategies.

These policies and strategies are to be implemented in phases as changes due to sea level rise occur.

The LCP LUP outlines policies for hazard zone properties, as well as a roadmap for adaptation to make the City more resilient to sea level rise. For instance, the City is exploring natural solutions to improve the biodiversity and resiliency of its beaches, while addressing the potential impacts of sea level rise. One such measure is a pilot program for dune creation in the North Beach area that successfully increased the height of the dunes and is now being expanded.

Other adaptive management actions that the City’s 2019 CAAP has identified as helpful in preparing the area for future coastal flooding as a result of a rise in sea level include:
• Conduct a financial cost analysis of future sea-level rise, including the costs of replacing or repairing the resources and facilities that would be impacted by coastal flooding, and quantifying the non-market losses or costs to the recreation and ecosystem services in the impacted area.30F
31 28 2019 Santa Monica CAAP, pg. 36. 29 Lindsay Call, Santa Monica’s Chief Resilience Officer and Emergency Operations Director, personal communication, December 16, 2024. 30 Assembly Bill (AB) 691 (Muratsuchi, 2013) requires local trustees of state lands to assess the impacts of sea-level rise on the coastal assets that they manage, and develop adaptation strategies to build resilience to coastal climate change impacts. 31 Coastal Flooding Action Item 1 (Resilient Buildings and Infrastructure in the Coastal Zone) in Santa Monica’s 2019 CAAP.

Local Hazard Mitigation Plan Section 11
City of Santa Monica, California
2025 Climate Change & Severe Weather Hazards Page 11-23 • Conduct site-specific vulnerability assessments of City-owned buildings, infrastructure and facilities in the coastal zone, and develop guidelines and standards for buildings and infrastructure to be either flood-proof or, at a minimum, be capable of accommodating temporary flooding.31F
32 • Integrate the latest sea-level rise projections into the Santa Monica Pier structural assessments and design improvements, and implement capital improvements that will help this structure withstand increased wave heights and on-shore flooding.32F 33 • Evaluate and adopt, as appropriate, shoreline management activities that address sea-level rise and coastal flooding with an emphasis on “soft” adaptation strategies such as managed retreat, beach nourishment, and dune restoration over “hard” adaptation strategies like seawalls.33F
34 To that end, the City of Santa Monica has been conducting dune restoration activities south of the Annenberg Community Beach House. These projects include installing fencing to restrict access to the dunes, planting seeds of California native vegetation, and adding interpretative signage to educate the public about local plant and bird species, native coastal habitats, and healthy beach management.
• Continue to monitor sea-level rise and coastal flooding impacts using tidal gage data, pier scour analysis, seasonal beach width, storm-flooding damage and other technologies as appropriate, and regularly update the coastal hazard maps (at a minimum every five years) using the best-available science. As climate-change impacts increase, phase in policies and projects identified in the Local Coastal Plan.34F
35 SEVERE WINDSTORMS
Windstorms, events of high windspeed, are a relatively common occurrence in southern California.

Severe windstorms are specifically defined as storms where wind gusts are at least 58 mph (50 knots).35F
36 Damaging winds include straight-line winds that do not rotate, tornadoes (where wind rotates), and downdrafts (which are small-scale columns of air that rapidly sink toward the ground).

Santa Ana winds and tornadoes are covered in more detail below. Downdrafts are divided by size into macrobursts and microbursts. A macroburst has a horizontal dimension at the ground surface of 2.5 miles (4 km) or more, whereas a microburst is smaller than 2.5 miles. These downdrafts typically are associated with thunderstorms.36F
37 Windstorm events can last several days (e.g., Santa Ana winds), a few hours (e.g., thunderstorms and tropical storms), or a few minutes (e.g., tornadoes, macrobursts, and microbursts). Santa Monica experiences significant Santa Ana wind events and sporadic tornado activity; both of these damaging winds have historically impacted the community.

32 Ibid 33 Coastal Flooding Action Item 3 (Climate-Ready Santa Monica Pier) in Santa Monica’s 2019 CAAP. 34 Coastal Flooding Action Item 4 (Adopt a Shoreline Management Plan) in Santa Monica’s 2019 CAAP. 35 Coastal Flooding Action Item 6 (Local Coastal Program Monitoring & Implementation) in Santa Monica’s 2019 CAAP. 36 https://www.nssl.noaa.gov/education/svrwx101/wind/faq/ accessed on September 19, 2024. 37 https://www.nssl.noaa.gov/education/svrwx101/wind/types/ accessed on September 9, 2024.

Local Hazard Mitigation Plan Section 11
City of Santa Monica, California
2025 Climate Change & Severe Weather Hazards Page 11-24 Santa Ana winds are a climatic condition unique to California characterized by strong, straight-line wind flows that come from the northeast and move downslope and offshore. Santa Ana winds are more prevalent between October and April. Whereas most severe winds are caused by intense storm systems like thunderstorms and tropical storms, Santa Ana winds are unique in that they occur in the absence of storms. Santa Ana winds
typically create hot, dry weather conditions
due to compressional heating of the
lower atmosphere. On average, Santa
Ana wind conditions occur five to ten
times a year, with each event lasting up
to a few days. Forecasters at the
National Weather Service usually
reserve the use of “Santa Ana” winds for
those over 25 knots, or ~29 miles per
hour (mph), although they have an
average wind speed of 40 mph (with
higher gust speeds). Severe Santa Ana
winds can reach speeds up to 80-100
mph in some areas, which can damage
or destroy buildings, knock over trees,
and damage power lines and electrical
equipment (potentially causing wildfires).

The NOAA National Centers for Environmental Information (NCEI) lists about 52 thunderstorm wind events in the Los Angeles County area between January 1950 and June 2024. The list also includes six (6) strong wind (37-42 knots) days and 239 high wind (>42 knots) days in the same area between January 1, 1996 and June 30, 2024.37F
38 Only the wind events that were deemed to have occurred closest to Santa Monica and were described as most extreme are included in Table 11-6, below.

The table highlights strong winds associated with Santa Anas and winter storms in the Santa Monica Mountains and coastal valley areas.

Table 11-6 shows that most significant Santa Ana winds in the region occur between the months of October and March, and tend to impact a wide area. Note that there is some inter-annual variability of Santa Ana wind events and no significant trends in intensity, duration or frequency of Santa Ana winds have been detected during the last century (Hall et al., 2018). High winds accompanying winter storms approaching from the north or northwest also occur most often between November and February, although winter storms can occur as early as August, and as late as May.

Table 11-6: Selected Extreme Wind Events Reported in the San Monica Region Through June 2024. Santa Ana Wind events are highlighted in yellow.

Date Wind Speed Description/Event Narrative
12/4/1957 Not reported Strong thunderstorm winds reported in the Redondo Beach area. 2/11/1959 Not reported Strong thunderstorm winds in the Santa Monica area. 8/17/1962 Not reported Strong thunderstorm winds in the northern Palos Verdes area. 5/8/1977 Not reported Strong thunderstorm winds in the Lakewood area. 38 https://www.ncdc.noaa.gov/stormevents/, accessed more recently on September 19, 2024.

Figure 11-8: Santa Ana Winds
Source: USGS at https://www.usgs.gov/media/images/santa-ana-winds Local Hazard Mitigation Plan Section 11
City of Santa Monica, California
2025 Climate Change & Severe Weather Hazards Page 11-25 Date Wind Speed Description/Event Narrative
3/2 (or 6)/1980 60 knots/69
mph
Strong downdraft wind near Dewey and Olympic in Los Angeles uprooted trees, tore down billboards and broke windows. Damages estimated at $10,000.
3/1/1981 Not reported Strong thunderstorm winds between Carson and Lakewood. 11/25/1996 30-85 knots/
35-98 mph
Strong surface high pressure over the Great Basin produced strong Santa Ana winds throughout the southern California area. Numerous trees and power lines were blown down.
11/28/1996 26-52/
30-60 mph
Strong winds from the northwest in the wake of a cold front downed numerous trees and power lines.
12/14&17/1996 83 knots/
96 mph
Strong Santa Ana winds. Sustained winds speed reached 45 to 55 mph with gusts up to 95 mph through passes and canyons. Numerous damages occurred, including many downed power lines which left thousands without electricity. Multiple injuries, one death in Los Angeles County on the 14th.
1/5/1997 86 knots/
99 mph
Strong Santa Ana winds with gusts to 99 mph caused extensive damage throughout the region. A man was killed when a tree fell onto him. At Burbank Airport the winds flipped over several planes.

Eleven cities at the foot of the Santa Monica / San Gabriel Mountains declared local states of emergency.
2/23-24/1997 52 knots/
60 mph
Strong Santa Ana winds developed in the region. With gusts to 60 mph. Numerous power lines were blown down. A downed power line in Santa Paula caused a house fire.
12/9/1997 63 knots/
72 mph
Strong winds flowing north to northeast with gusts up to 72 mph reported. Tree blew down onto I-10 in Covina and van ran into it; in Santa Clarita an eucalyptus tree was blown down onto a parked vehicle; numerous power outages; 15 boats destroyed in Avalon Harbor on Catalina Island.
2/2-3/1998 78 knots/
90 mph
Powerful winter storm slammed into southern California with powerful winds buffeting the area. Hundreds of trees and power lines were blown down, resulting in numerous outages. Winds were accompanied by intense rains, leading to flooding and mudslides closing sections of several highways.
2/5/1998 61 knots/
70 mph
Powerful storm slammed into central and southern California.

Powerful winds buffeted the entire area. Strong winds, gusting up to 70 mph, knocked down many trees and power lines. Rainfall totals ranged from 1 to 3 inches over coastal areas, up to 6 inches in the mountains. Numerous flooding problems were reported across the area.
2/7-8/1998 61 knots/
70 mph
Strong winds associated with a winter storm knocked down many trees and power lines. In Encino the winds knocked down Lang Oak, a 1000-year-old oak. Winds accompanied widespread flooding and mudslides.
5/13/1998 60 knots/
70 mph
Strong thunderstorm winds produced damage in the Long Beach area.

The roof of a couple of service bay areas was blown off at a car dealership, and a 600-square-foot section of roof was torn off an aircraft instrument company next door.
12/9/1998 66 knots/
76 mph
Powerful Santa Ana winds measured at about 69 mph in the coasts and valleys and up to 76 mph in the mountains knocked down numerous power lines causing many power outages. In Glendale the winds fueled a brush fire that was ignited by a downed power line.

Local Hazard Mitigation Plan Section 11
City of Santa Monica, California
2025 Climate Change & Severe Weather Hazards Page 11-26 Date Wind Speed Description/Event Narrative
4/3/1999 55 knots/
63 mph
Strong northwest winds across central and southern California with sustained winds of 35-45 mph and gusts to 65 mph. Widespread power outages and felled trees reported. A tree in Long Beach fell and blocked two lanes of traffic on the 710 Freeway. The Catalina Island Yacht Club reported severe wind damage to their quarter deck. 11/21-22/1999 46-63 knots/
53-72 mph
Strong Santa Ana winds buffeted the region. The winds snapped a support cable on the Vincent Thomas Bridge in San Pedro, closing several lanes of traffic. In Studio City the winds blew down a construction wall at Universal City Walk, injuring 7 people. 12/2/1999 67 knots/
77 mph
Strong offshore winds caused numerous trees and power lines to be blown down.
2/23/2000 50 knots/

57.5 mph
Powerful Pacific storm brought heavy rain, thunderstorms and snow to southern California. Strong winds in Central Los Angeles damaged roofs and blew down power lines. One downed line electrified a fence, which in turn electrocuted and injured a woman.
3/5/2000 60 knots/
70 mph
Severe thunderstorm struck Long Beach and blew down numerous power poles near the intersection of Stearn Street and Redondo Lane. 4/18/2000 70-87 knots/

80.5-100 mph
Severe thunderstorm produced microburst winds estimated at 80-100 mph. More than 30 mobile homes in Paramount were damaged; one was blown over. Structural damage to several homes and businesses in Bellflower, Downey, Norwalk, Whittier, La Mirada and to the east.

Destruction of chimneys and concrete walls; numerous trees and power poles blown down. In Norwalk a 100-foot eucalyptus tree closed all southbound lanes of the I-5 for three hours. 2/13/2001 45 knots/
52 mph
Powerful Pacific storm brought heavy rain, snow and gusty winds to central and southern California. In the coastal areas, winds 30-50 mph produced some damage. In San Pedro Harbor several docks were damaged and one boat sunk.
4/20/2001 50 knots/

57.5 mph
Strong thunderstorm winds struck near the community of Baldwin Hills. Three trees were blown down along South Redondo Avenue; one person was injured when they drove through debris on that road. 3/13/2002 16-22 knots/
30-40 mph
Gusty winds knocked down some trees across the Los Angeles County, causing minor damage. In Los Angeles winds knocked down a 50-foot tree onto a van; in Studio City winds knocked down a tree onto a UPS truck; and in Hollywood, winds knocked down a tree onto a car. No injuries reported as a result of these incidents. 11/25/2002 57-70 knots/
66-81 mph
Powerful Santa Ana winds buffered Los Angeles and Ventura counties. Thousands left without power after winds snapped power lines. Many trees were blown down. In Glendale, snapped power lines sparked three house fires.
1/6/2003 65 knots/
75 mph
Powerful Santa Ana winds buffeted Los Angeles and Ventura counties. Gusts knocked down numerous trees and power lines, closing several roads. In the Santa Monica Mountains north of Malibu, the winds fueled a 2,200-acre brush fire that destroyed two structures.
4/18/2004 70-87 knots/
80-100 mph
Severe thunderstorm caused structural damage in Paramount, where 30 mobile homes were damaged, including one that was blown over.

The storm also did damage in Downey, Norwalk, Whittier, La Mirada, Rowland Heights and Diamond Bar, damaging chimneys, concrete walls, and knocking over numerous trees and power poles.

Local Hazard Mitigation Plan Section 11
City of Santa Monica, California
2025 Climate Change & Severe Weather Hazards Page 11-27 Date Wind Speed Description/Event Narrative
A 100-foot-tall eucalypts tree was blown down across Interstate 5, closing all southbound lanes for 3 hours.
10/18 &
26/2006
56 knots/
64 mph
Strong Santa Ana winds with gusts to 65 mph in the Santa Monica Mountains recreational area.
11/28-30 &
12/2-3/2006
56 knots/
64 mph
Strong Santa Ana winds in Los Angeles and Ventura counties caused scattered power outages as a result of downed power lines. Gusts to 64 mph reported in Malibu Hills. Near Moorpark the winds helped fan the Shekell wildfire.
12/22/2006 54 knots/ Strong northerly winds developed behind a cold front caused several thousand people in Los Angeles County to lose power due to downed power lines.
12/28/2006 62 knots/
71 mph
A fast-moving storm system moved through Southern California. The main weather associated with this storm system was the gusty offshore winds that developed behind the storm. The gusty winds affected Santa Barbara, Ventura and Los Angeles counties and gusted as high as 100 mph. Widespread power outages were reported across the area due to downed power lines. Multiple injuries, one reported death from drowning at sea.
1/15/2007 56 knots/64
mph
A cold arctic storm brought widespread freezing temperatures and some gusty offshore winds to the area. Across the agricultural areas of San Luis Obispo, Santa Barbara, Ventura and Los Angeles counties, the freezing overnight temperatures nearly $350 million in crop damages. In the windier spots of the Los Angeles County mountains, wind gusts between 60 and 65 mph were reported.
9/21/2007 52 knots/
60 mph
Early season cold storm brought significant weather to southern California, including intense rainfall and strong winds. Severn power poles were downed in Hollywood.
10/21/2007 56 knots/
64 mph
Santa Ana winds. Four of the wildfires exceeded 700 acres with one fire burning nearly 60,000 acres in the county.
2/14/2008 65 knots/
75 mph
Strong northerly offshore winds reported in the Santa Monica Mountains area.
5/21/2008 74 knots/
85 mph
Cold system brought strong winds, thunderstorms, hail and flash flooding to southern California. Northerly gusts 58-85 mph reported.

Flooding and lane closures reported along I-10 and I-605. 10/13/2008 69 knots/
79 mph
Strong high-pressure system over the Great Basin produced gusty northeast winds with peak wind gusts between 60-85 mph. 1/9/2009 52 knots/
60 mph
Strong gusty Santa Ana winds across Ventura and Los Angeles counties with gusts 60-73 mph.
10/27/2009 70 knots/

80.5 mph
Powerful early season storm produced very strong gusty winds that knocked down power lines and trees, leading to numerous electric outages.
1/21/2010 52 knots/
60 mph
Powerful winter storm brought heavy rain, flash flooding and gusty winds, with gusts of 60 mph. Wind gusts downed several trees in the Downey and Pico Rivera areas.
12/29/2010 54 knots/
62 mph
Winter storm, produced between 0.50 and 1.50 inches of rainfall across the area. This storm system produced strong and damaging northerly winds across the area. With the ground already saturated from previous rainfall, the strong winds toppled many trees, producing scattered power outages and road blockages.
2/2/2011 67 knots/
77 mph
Santa Ana wind event with gusty winds between 60-67 mph in the Santa Monica Mountains and Malibu Hills.

Local Hazard Mitigation Plan Section 11
City of Santa Monica, California
2025 Climate Change & Severe Weather Hazards Page 11-28 Date Wind Speed Description/Event Narrative
11/2/2011 72 knots/
83 mph
Strong Santa Ana winds up to 83 mph in the mountains and 59 mph in the coastal plain.
11/30-
12/1/2011
63 knots/

72.5 mph
Strong Santa Ana winds with widespread wind gusts 60-70 mph.

Widespread power outages; in the San Gabriel Valley over 350,000 residents lost power. In Pasadena 42 buildings were red-tagged due to wind damage. Strong winds at LAX forced 23 flights to be diverted to Ontario.
10/25-26/2012 70 knots/
81 mph
Strong Santa Ana winds with gusts as high as 81 mph in the mountains of Los Angeles County.
1/17/2013 66 knots/
76 mph
Strong gusty Santa Ana winds with winds as high as 76 mph reported. 5/2/2013 64 knots/
74 mph
Strong Santa Ana winds with gusts to 74 mph reported. In Ventura County the winds helped spread the 24,000-acre Springs Fire. 10/4/2013 78 knots/
90 mph
Strong Santa Ana winds in the Santa Monica Mountains with sustained winds as high as 54 mph and gusts to 90 mph.
12/9-14/2013 80 knots/
92 mph
Strong Santa Ana winds with gusts to 92 mph across the Santa Monica Mountains and Malibu Hills.
12/29/2013 76 knots/
87 mph
Another round of Santa Ana winds with sustained winds to 62 mph and gusts to 87 mph.
4/29/2014 56 knots/
64 mph
Santa Ana winds. As the winds developed, a couple of small wildfires occurred across the mountains of Ventura and Los Angeles counties, but did not grow to any significant levels.
11/16/2014 64 knots/
64 mph
Santa Ana winds in the Santa Monica Mountains and Malibu Hills with gusts to 74 mph.
12/21/2014 70 knots/
82 mph
Strong Santa Ana winds with gusts 65-82 mph reported in the Santa Ana Mountains and Malibu Hills.
12/30/2014 68 knots/
78 mph
Strong gusty Santa Ana winds in the mountains of Los Angeles County, and extending offshore to Catalina Island where 2 people died when swept overboard and crushed between a boat and rocks due to winds.
1/23-24/2015 66 knots/
76 mph
Strong gusty Santa Ana winds with gusts to 79 mph.
12/11/2015 69 knots/
79 mph
Strong northerly pressure gradient generated strong and gusty north winds with gusts to 79 mph.
3/7/2016 52 knots/
60 mph
Powerful late season storm brought heavy rain, flash flooding and strong winds to the area. Winds knocked down several trees, including one large tree in Cerritos.
1/22/2017 72 knots/
83 mph
Strong winter storm brought heavy rain, snow and strong winds to the region. Gusts to 83 mph reported.
2/17/2017 51 knots/
59 mph
A powerful winter storm moved across southwestern California, bringing heavy rain and snow, strong winds and flash flooding to the area. Rainfall amounts ranged from 2 to 6 inches across coastal areas with up to around 10 inches in the local mountains. This heavy rain produced numerous reports of flash flooding as well as mud and debris flows. In the local mountains, snowfall totals between 1 and 2 feet were reported at the resort level. Strong southerly winds accompanied the storm with wind gusts up to around 70 mph reported in some areas.
10/9/2017 65 knots/
75 mph
Strong Santa Ana winds reported in the Santa Monica Mountains and Los Angeles County with gusts between 64 and 75 mph.

Local Hazard Mitigation Plan Section 11
City of Santa Monica, California
2025 Climate Change & Severe Weather Hazards Page 11-29 Date Wind Speed Description/Event Narrative
12/4-5/2017 63 knots/
73 mph
Santa Ana winds. North to northeast wind gusts up to 73 mph were reported. During this event, the Thomas Fire ignited across Ventura County, eventually spreading into Santa Barbara County. 4/9/2019 64 knots/
74 mph
Strong gusty northwest to north winds impacted the mountains in Ventura and Los Angeles Counties, with gusts to 74 mph. 11/25/2019 77 knots/
89 mph
Strong and gusty northerly winds with gusts to 89 mph reported in some areas.
10/26/2020 83 knots/

95.5 mph
Strong and gusty Santa Ana winds buffeted sections of Los Angeles and Ventura counties, with gusts 70-95 mph in the mountains, and 60-75 mph in the valleys.
12/2-3/2020 74 knots/
85 mph
Strong, gusty Santa Ana winds impacted the mountains and valleys of Los Angeles and Ventura counties, with gusts 58-85 mph reported. 1/19/2021 86 knots/
99 mph
Very strong Santa Ana winds with gusts to 99 mph downed numerous small trees and branches in the Los Angeles and Ventura counties. 10/4/2021 51 knots/
59 mph
Strong thunderstorms generated strong outflow winds with gusts to 78 mph in the southern Santa Monica Mountains and near Malibu. 11/24-25/2021 74 knots/
85 mph
Very strong, gusty Santa Ana winds with gusts to 89 mph reported in the mountains of Los Angeles County.
1/14/2022 70 knots/
80 mph
Strong gusty Santa Ana winds impacted the mountains in Los Angeles County with gusts between 61-80 mph.
11/15-16/2022 89 knots/
102 mph
Very strong, gusty Santa Ana winds impacted many areas of Los Angeles and Ventura counties, with gusts >100 mph in the mountains, and gusts 60-80 mph reported in other areas, including Malibu Coast.
11/24/2022 86 knots/
99 mph
A third round of gusty Santa Ana winds in the mountains and valleys of Los Angeles and Ventura counties, with gusts to 99 mph. 12/10/2022 79 knots/
91 mph
Powerful winter storm brought rain, snow and gusty winds to southern California. Strong southerly winds >80 mph reported. 1/9/2023 82 knots/
94 mph
Power atmospheric river brought rain, flooding and gusty winds to the mountains and foothills. Strong southerly winds >90 mph measured in the mountains of Los Angeles County.
1/26/2023 61-97 knots/
70-108 mph
Strong northerly winds impacted the mountains of Los Angeles County with peak wind gusts >100 mph.
1/30-31/2023 58-70 knots/
67-80.5 mph
Strong gusty north to northeast winds impacted the Malibu Coast area and other areas in the western Santa Monica Mountains. Gusts to 80 mph reported.
02/24/2023 81 knots/
93 mph
Powerful winter storm brought heavy rain, snow and strong winds to southern California. Peak gusts of 93 mph were reported. About 25 uprooted trees and downed limbs were reported in Santa Monica.3 8F 39 3/1/2023 48 knots/
55 mph
Moderate winter storm brought rainfall and scattered thunderstorms with gusty winds to the coastal plain of Los Angeles County. Winds uprooted trees and blew shingles off roofs. One person was injured by wind-blown debris. Communities most impacted are located between Downey and Montebello.
10/29/2023 54-90 knots/
62-104 mph
Strong gusty north to northeast winds with widespread gusts in the 60-70 mph range, and localized gusts to 100 mph.
11/19-20/2023 52-81 knots/
60-93 mph
Strong and gusty Santa Ana winds impacted many areas in Los Angeles County, with northeasterly wind gusts up to 93 mph.

39 https://smdp.com/2023/02/28/winter-storm-2/ accessed September 24, 2024.

Local Hazard Mitigation Plan Section 11
City of Santa Monica, California
2025 Climate Change & Severe Weather Hazards Page 11-30 Date Wind Speed Description/Event Narrative
12/7-9/2023 56 knots/
64 mph
Strong and gusty north to northeast winds impacted the western Santa Monica Mountains. Gusts to 79 mph reported.
1/6-7/2024 52-61 knots/
60-70 mph
Strong gusty winds impacted the western Santa Monica Mountains, with gust to 70 mph.
1/11/2024 51 knots/
59 mph
Strong gusty winds impacted the western Santa Monica Mountains, with gust to 78 mph.
2/7/2024 62 knots/
71 mph
Strong winter storm brought rain and strong winds to the area.

Thunderstorms and tornadoes reported, with sensor at Saddle Peak in the southern Santa Monica Mountains by Malibu reporting gusts of 62 knots.
2/19/2024 43 knots/

49.5 mph
Thirds powerful winter storm brought rain, flooding, debris flows to the area, and gusty winds. Strong winds knocked down tree across the southbound lanes of Topanga Canyon Boulevard near its intersection with Grand View Drive. Mudslide across Highway 1 near Topanga Beach, and several boulders closed other roads in Malibu. 12/9-10/2024 59-81 knots
68-93 mph
Strong Santa Ana winds fanned the Franklin Fire that started in Malibu Creek State Park on the evening of December 9th and spread, igniting in total more than 4,000 acres. On the 10th, at one point the winds were so strong that the fire tripled in size in just one hour.

Wind speeds recorded during the Franklin fire include sustained winds of between 30 and 60 mph, with gusts that ranged between 68 and 93 mph.
1/7-8/2025 52-87 knots/
60-100 mph
Extremely strong Santa Ana wind event fanned the Pacific Palisades and Eaton fires that caused widespread destruction in the Los Angeles region. Peak winds during this event in the Pacific Palisades area were reported at about 60-70 mph, with gusts up to 80 mph, whereas in the Eaton area, peak winds were in the 70-80 mph range, with some gusts exceeding 100 mph. The strong winds caused the Pacific Palisades to grow from 20 acres to 200 acres in the span of 20 minutes, and to more than 1,200 acres in the span of an hour. Strong winds at night grounded firefighting aircraft.

Sources: NCEI storm event database (https://www.ncdc.noaa.gov/stormevents/), most recently accessed September 23, 2024. For the two most recent events, data was compiled from https://en.wikipedia.org/wiki/Palisades_Fire, https://www.linkedin.com/pulse/santa-ana-wind-analysis-palisades-eaton-wildfires-jason-shafer-p8pre/, and https://www.nbclosangeles.com/news/california-wildfires/timeline-eaton-palisades-fires-la-county/3614940/, all accessed on March 10, 2025.

Tornadoes, another type of severe winds, are violently rotating columns of air that extend from a thunderstorm to the ground (Figure 11-939F
40), occurring most often when warm, moist air meets a cold front. In the United States, tornadoes are most common during the spring and summer months in the Central Plains, east of the Rocky Mountains, but it is important to note that tornadoes can occur anywhere. In coastal regions, for example, tornadoes can accompany tropical storms and hurricanes

40 Source: https://www.yahoo.com/news/tornado-california-not-rare-might-think200755846.html?guce_referrer=aHR0cHM6Ly93d3cuYmluZy5jb20v&guce_referrer_sig=AQAAABBWGcWLb_qkhWW4CabKz bsU8HG-qIkx58i-2V0a9JBj7yax-vYm-Ljfy30TLhqFEluILdcFP1EpGYjz5k0z4_WJAvl472WhaqFuYfzJ50maw4MsQYqE1y6QEpOcDlMYgiYmlRwH7llK17R7ptPwaNyyfOPJRq13SkJPxfOO54H&guccounter=2, accessed November 19, 2024.

Local Hazard Mitigation Plan Section 11
City of Santa Monica, California
2025 Climate Change & Severe Weather Hazards Page 11-31 as they move on land, where they usually occur to
the right and ahead of the path of the storm center
as it comes onshore.40F
41 Based on data collected
between 1950 and 1991, peak tornado occurrence
in California is between January and April.

The most violent tornadoes are capable of tremendous
destruction with wind speeds of 250 mph or more.

Damage paths can be more than one-mile wide and 50
miles long. The Enhanced Fujita Scale or EF Scale (Table 11-7) is used to assign a tornado a “rating” based on
estimated wind speeds and related damage. The scale
measures six classifications of tornadoes with increasing magnitude from a 0 to 5. Most (69%) of tornadoes have
an F0 and F1 rating. While only 2% of tornadoes have
an F4 or F5 rating, these tornadoes are responsible for 70% of all tornado-related deaths.41F 42 Table 11-7: Enhanced Fujita Scale
EF Rating
Wind Speed
Estimate
(mph)
Typical Damage
0 65-85 Light damage (gale tornado). Some damage to chimneys and television antennas; twigs and branches break off trees; winds push over shallow-rooted trees; sign boards are damaged.
1 86-110 Moderate damage (weak tornado). Winds peel off roofs; windows break; light trailer homes are pushed off their foundations or overturned; some trees are uprooted or snap; moving autos are pushed off the road; attached garages may be destroyed.
2 111-135 Considerable damage (strong tornado). Roofs are torn off frame houses, leaving strong walls upright; weak rural buildings are demolished; trailer homes are destroyed; large trees snap or are uprooted; railroad boxcars are pushed over; light objects become airborne missiles; cars are blown off highways.
3 136-165 Severe damage (severe tornado). Roofs and some walls are torn off wellconstructed frame structures; some rural buildings are completely demolished; trains are overturned; steel-framed hangars and warehouse-type structures are torn; cars are lifted off the ground; most trees are uprooted, snapped or leveled.
4 166-200 Devastating damage (devastating tornado). Well-constructed frame houses are leveled, leaving piles of debris; steel structures are badly damaged; trees are de-barked by small flying objects; cars and trains are thrown some distances or roll considerable distances; large objects become missiles. 5 Over 200 Incredible damage (incredible tornado). Strong, whole-frame houses are lifted off their foundations and carried considerable distances; steelreinforced concrete structures are badly damaged; automobile-sized missiles are generated and carried through the air >100 meters; trees are debarked.

41 https://www.nssl.noaa.gov/education/svrwx101/tornadoes/, accessed on September 19, 2024. 42 https://www.weather.gov/mkx/taw-tornado_classification_safety and https://www.spc.noaa.gov/faq/tornado/#Damage, both accessed most recently in September 2024.

Figure 11-9: Funnel Cloud Over the
Ocean off Venice Beach, Feb. 22, 2005
(AP Photo/Chris Kim/File)
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2025 Climate Change & Severe Weather Hazards Page 11-32 The south coastal region of California, including the Los Angeles Basin, has the greatest incidence of tornadoes in the State, with 46 tornadoes reported in the region between 1950 and June 2024. 42F 43 While these tornadoes were all rated between F0 and F2 (relatively weak) on the Fujita scale, they incurred an estimated $61.195 million in damages.43F
44 Buildings in coastal southern California,
including Santa Monica, in accordance with the most recent California Building Code, are to be designed to withstand wind speeds of between about 90 and 105 miles per hour (mph); the design wind speed for most new residential structures in Santa Monica is 94 mph. These design wind speed values are lower than those used elsewhere in the United States. For example, design wind speed values for the Gulf Coast region (east Texas to Florida), range from about 130 to 180 mph, and the “tornado” alley area from Oklahoma to Minnesota has been assigned wind speed design values of between 110 and 114 mph.44F
45 Although tornado shelters, safe rooms, or basements are not mandatory in Oklahoma, Kansas and other states susceptible to tornado activity, these structures are recommended. No such requirements or recommendations exist for the southern California region.

The vast majority of the tornadoes that have impacted the Los Angeles region occurred in the fall and winter months (Table 11-8). Fewer tornadoes occur during the warmer months primarily due to the stabilizing effect of the marine layer, and the lack of dynamic forcing during the warmer months.

Table 11-8 lists 29 past tornado events within an approximately 20-mile radius of Santa Monica.

Note that several of the tornados listed are part of a group of tornados reported the same day or couple of days, related to a larger storm system that impacted the region at that time. Two of the tornados occurred in Santa Monica. These are shown in bold. Photographs of the damage caused by the 1952 tornado or tornados in Santa Monica can be seen here. The 1952 tornados killed three people and is one of only two tornadic events in California with reported fatalities.

Table 11-8: Tornado Events in the Santa Monica Region
Date Deaths/Injuries Fujita Scale Location; Damages
3/16/1952 3/1 NA
In Santa Monica left 3 dead and caused damage. Reports
suggest two separate tornados touched down. One
damaged several structures and vehicles, the other
scattered four boats in a boatyard at Lincoln and
Olympic Boulevard. One builder was injured. Costs of
damage not provided.
1/18/1955 0/0 NA $2.5K in property damage
5/9/1956 0/1 0 $25K in property damage
5/14/1962 0/0 1 $25K in property damage
11/9/1964 0/0 1 In El Segundo; $2.5K in property damage 11/7/1966 0/10 2 Began near Redondo Beach, ended NE of Compton; >$250K in property damage
4/18/1967 0/0 0 In Santa Monica; $2.5K in property damage, including to power lines and a few homes
2/10/1978 0/0 0 In El Segundo; $0 in property damage
1/31/1979 0/0 0 Near Universal City; $2.5 million in property damage 1/28/1980 0/0 0 In Gardena; $2.5K in property damage

43 https://www.ncdc.noaa.gov/stormevents/ accessed on September 19-20, 2024. 44 Ibid 45 https://codes.iccsafe.org/content/CABC2022P4/chapter-16-structural-design#CABC2022P4_Ch16_Sec1609, accessed November 19, 2024.

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3/29/1982 0/0 1
In South San Gabriel; two-block-wide area of uprooted
trees, downed store signs, substantial roof damage,
fences blown down, power poles down, small avocado
orchards partially destroyed.
11/9/1982 0/0 1
In Malibu; waterspout observed prior to tornado making
landfall. Three different touch points. Major damage to several homes and retail businesses, heavy rain and hail.

Catamaran blown about 125 feet into air. $25K in
property damage.
11/9/1982 0/0 2 In San Fernando Valley; caused about $250K in damage at a department store; $2.5 million in total damages.
11/9/1982 0/0 2 From Long Beach inland to Cerritos; $2.5 million in property damage.
11/9/1982 0/0 0 Small tornado reported in Inglewood; $2.5K in property damage.
3/1/1983 0/30 2
From Inglewood to South Central Los Angeles,
approximately 50 homes and 7 businesses were
damaged. $25 million in damages.
3/1/1983 0/0 0 In South Pasadena, north of Huntington Drive; $250 in damages.
9/30/1983 0/0 0
In Walnut Park, 6 miles SSE of Los Angeles Civic Center; window damage in four homes, torn shingles or broken
roof tiles; the porch of one home was torn from the
house and deposited on the roof; several small trees
uprooted; about $250K in property damage.
9/30/1983 0/3 2
In Hawthorne; severe damage to 8 homes; substantial
damage to 15 homes, and minor damage to 45 homes
and 36 vehicles; one pickup destroyed. Several large
trees uprooted trees. $250K in property damages.
3/19/1991 0/0 0
Small tornado in the Lakewood-Bellflower area near Del
Amo Blvd.; light damage to two roofs that were blown
off, windows, vehicles, trees and power lines blown
down. Total damage cost not provided.
3/20/1992 0/0 1
Small tornado struck a one-block strip of the El Sereno district in Los Angeles; wind speeds up to 100 mph, roof and window damage, uprooted trees, toppled a billboard
onto a car, damaged 10 homes. Total damage cost not
provided.
1/14/1993 0/0 1
Strong winds and intense rain ripped through small
section of Los Angeles area damaging 3 houses, 2 cars,
and uprooting at least 50 trees. $500K in property
damage estimated.
2/7/1994 0/0 0
Weak tornado touched down along Sunland Blvd. and
San Fernando Rd.; window damage, uprooted trees; one
tree fell onto car. $50K in property damages.
4/1/1999 0/0 0 Small tornado touched down in Chatsworth; two mobile homes damaged. Damage cost not provided.
12/28-29/2004 0/0 0
Pacific storm with heavy rain, snow and tornados. On the coastal plain of Los Angeles County, weak tornados were reported in Long Beach, Inglewood and Whittier. The
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tornados only produced minor damage including downed
trees and damaged roofs. Damage costs not provided.
12/12/2014 0/0 0
Weak tornado near Inglewood, west of I-110; the tornado damaged the roof of an apartment complex, two
residential roofs and a steel billboard. Damage costs not provided.
3/22/2023 0/0 1
Weak tornado in Montebello, near intersection of
Washington Blvd. and Maple Ave.; substantial damage to
an industrial warehouse where roof nearly collapsed,
damage to 17 commercial buildings, and numerous
vehicles damaged by flying debris. Damage costs not
provided.
5/4/2023 0/0 0
Weak tornado near Carson; minor damage reported to a
couple of buildings and vehicles. Damage costs not
provided.
5/4/2023 0/0 0
Weak tornado in the community of Compton; one power
line and several tree branches were downed, roof damage to a couple of houses. Damage costs not provided.

Source: NCEI storm event database (https://www.ncdc.noaa.gov/stormevents/) last accessed on September 20, 2024.

The effects of climate change on windstorms remains uncertain. A 2019 study45F 46 reported that climate
change has suppressed Santa Ana winds, but the same research team published new findings in 202146F

47. Their new work shows that while “cold” Santa Ana winds occurring during the winter months have become less common, there is no clear trend for “hot” Santa Ana winds during the fall months (which is also the time period when Santa Ana winds pose the highest threat for wildfires).

These findings may have to be revisited following the strong Santa Ana winds that have been experienced in the Los Angeles region in the past four years during the winter months (see Table 11- 6). What it is clear from the recent wind-fanned wildfires that have caused extensive damage, unhealthy air quality, and loss of life in the region is that the extreme variations in weather brought on by climate change can combine to create the “perfect storm.” Thus, extreme wet winters dominated by atmospheric rivers boost vegetation growth; if these wet years are followed by a drought period characterized by extreme heat and little to no precipitation, the abundant vegetation dies, creating a thick cover of flammable vegetation, or fuel load. If these events are followed by strong winds, a firestorm can easily develop.47F
48 This is discussed in more detail in Section 10.

Projections for tornadoes are similarly unclear. Some research shows that tornadoes and severe thunderstorms are increasing in occurrence in the U.S., with extreme tornado outbreaks especially

46 Guzman‐Morales, J., and Gershunov, A., 2019, Climate change suppresses Santa Ana winds of Southern California and sharpens their seasonality: Geophysical Research Letters, Vol. 46, No. 5, pp. 2772-2780, available at https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018GL080261. 47 Gershunov, A., Guzman Morales, J., Hatchett, B., Guirguis, K., Aguilera, R., Shulgina, T., Abatzoglou, J.T., et al., 2021, Hot and cold flavors of southern California’s Santa Ana winds: their causes, trends, and links with wildfire:

Climate Dynamics, Vol. 57, No. 7, pp. 2233-2248; available at https://link.springer.com/article/10.1007/s00382- 021-05802-z. 48 Lindsay, R., 2025, The weather and climate influences on the January 2025 fires around Los Angeles; article published on 19 February 2025 by NOAA; available at https://www.climate.gov/news-features/eventtracker/weather-and-climate-influences-january-2025-fires-around-los-angeles.

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2025 Climate Change & Severe Weather Hazards Page 11-35 becoming more frequent.48F
49 However, other scientists show that tornado trends vary regionally:
tornadoes are becoming more frequent in the Southeast and less frequent in the Great Plains.49F 50 However, due to the relative infrequency of tornadoes in California, we do not yet have an understanding of tornado trends here.

Social Vulnerability to Windstorms
The impacts of windstorms in Southern California range from minor to severe and even lifethreatening. For example, Santa Ana winds are mostly a nuisance to Southern California residents, bringing dust indoors, breaking tree branches, and causing minor damage. For people with respiratory ailments, Santa Ana winds may often mean headaches, sinus pain, difficulty breathing, and even asthma.

Some severe impacts of windstorms include property damage, igniting and spreading fires, toppling trees and powerlines, and disrupting public utilities, telecommunications, and transportation routes.

Falling trees are a particularly common and potentially costly outcome of windstorms. Some tree limbs can break in winds of about 45 mph, meaning that damage can occur in even minor windstorms. Downed trees pose the greatest threat to utilities and infrastructure and, historically, trees downed during a windstorm have been the major cause of power outages in the southern California area. Uprooted trees and downed utility poles can also fall across the public right-of-way disrupting transportation. These events can be major hindrances to emergency response and disaster recovery. For example, if transportation routes are compromised by fallen debris, and loss of power occurs in the area, emergency response facilities like the hospital, fire stations, and the police station may find it difficult to function effectively. In Santa Monica, typical cleanup following a large windstorm event typically costs the City about $5,000.00.50F 51The January 7, 2025 windstorm caused
over $180,000 in costs, including work to clear almost 50 fallen trees, 122 tree limb failures, and transport 375 tons of vegetation debris to appropriate landfills.

Falling or flying debris, falling trees and downed power lines can also directly injure or kill motorists and pedestrians. For example, in 2003, two deaths were blamed on Santa Ana winds: a falling tree struck and killed a woman in San Diego, and a passenger in a vehicle was struck by a flying pickup truck cover (http://cbsnews.com/ January 8, 2003 article).

Windstorms in Southern California, especially Santa Ana winds, are also often connected to wildfires. Because Santa Ana winds occur when the air humidity is low to very low, they can create wildfire-favorable conditions by drying out vegetation and making it more flammable. Santa Ana winds can also help fire and embers travel at an alarming pace, thereby spreading existing fires and posing a serious concern to firefighters. The instances of fire events either stemming from or being

49 Tippett, M.K., Lepore, C., and Cohen, J.E., 2016, More tornadoes in the most extreme US tornado outbreaks: Science, Vol. 354, No. 6318, pp. 1419-1423; available at https://www.science.org/doi/pdf/10.1126/science.aah7393. 50 Gensini, V.A. and Brooks, H.E., 2018, Spatial trends in United States tornado frequency: NPJ Climate and Atmospheric Science, Vol. 1, Article No. 38; available at https://www.nature.com/articles/s41612-018-0048-2 and
Graber, M., Trapp, R.J., and Wang, Z., 2024, The regionality and seasonality of tornado trends in the United States: npj Climate and Atmospheric Science, Vol. 7, Issue 1, Article No. 144; available at https://www.nature.com/articles/s41612-024-00698-y 51 Lindsay Call, Santa Monica’s Chief Resilience Officer and Emergency Operations Director, personal communication, December 16, 2024.

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2025 Climate Change & Severe Weather Hazards Page 11-36 aggravated by windstorms is evident in Table 11-5.

Winds occurring during thunderstorms, like tornadoes and microbursts also pose extreme danger to humans and infrastructure. These winds are particularly dangerous to aircraft landing or taking off, and have caused several planes to crash, with resultant loss of life. Tornadoes and microbursts have also been responsible for capsizing and sinking ships, causing structural damage in many communities, lifting roofs off structures, downing electrical lines, and generally causing millions of dollars in damage. Again, tornadoes and microbursts are not nearly as common in California compared to the northeastern and central parts of the United States.

Unlike other natural hazards, there are not spatial patterns of where windstorms occur: a windstorm event may occur anywhere in the City, and windstorm events are not readily predictable. For example, while flooding hazards are generally confined to a discrete area that can be mapped, windstorms may travel in any direction, and are only partly affected by topography (with stronger winds usually observed in canyons and passes, where the winds are funneled by the surrounding topographic highs). Given that we cannot predict when or where a windstorm will occur, nor its intensity, the conservative approach is to assume that a windstorm event can take place anywhere in the Santa Monica area anytime during the year, but preferentially in the fall or winter.

There are differences in vulnerability when winds do occur, however. For example, while any structure may be susceptible to damage (based on its age, condition, and structural design), buildings with weak reinforcements are most susceptible to windstorm damage. People living in older buildings or buildings without modern structural improvements may be more at risk of wind damage.

Mobile homes are also particularly susceptible to windstorm damage, and thus low-income populations may be particularly vulnerable to wind events.

Finally, windstorms may at times necessitate involvement of City maintenance personnel responding to cleanup and repairs during and following such an event, or preceding a windstorm to secure facilities. Higher income areas or areas with higher population may receive priority in the City’s response. In extreme situations, such as if emergency vehicles personnel are unable to pass due to fallen trees or debris, this difference in road clean-up time, could contribute to loss of life.

Activities for Windstorm Mitigation and Response
Windstorm mitigation activities include programs and activities implemented by State and City agencies or individuals to prevent or reduce the severity of impacts from windstorms. As shown on the tables above, one of the most common problems associated with windstorms are power outages resulting from fallen power poles and downed trees and branches. Thus, one of the most useful and common existing mitigation strategies pertain to tree clearance.

Specifically, California law requires utility companies to maintain clearances (specified distances based on the type of voltage running through the line) between electric lines and all vegetation.

Enforcement of the following California Public Resources Code Sections provides guidance on tree regulations: 4291–Reduction of Fire Hazards Around Buildings; 4292–Power Line Hazard Reduction; and 4293–Power Line Clearance Required.

Tree clearance is also an important action for homeowners because many insurance companies do not cover windstorm related damages if the policyholder has refused to allow the hazard to be eliminated. Undergrounding of overhead utility lines can help reduce the impact of windstorms on Local Hazard Mitigation Plan Section 11
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2025 Climate Change & Severe Weather Hazards Page 11-37 the power system, while improving the aesthetics of the community. However, it is significantly more expensive to install and maintain underground power lines compared with overhead lines, so electric energy providers generally avoid undergrounding utilities. Fixing power outages takes longer and is more expensive when buried cables need to be accessed and repaired.

Following several devastating brush fires started and fanned by strong winds (such as the Paradise Fire in northern California in 2018; see Section 8), electrical utility companies now often turn off power in advance of strong wind storm events. This policy limits the potential for downed electric lines to generate a fire that then turns deadly, with the potential to impact a large section of a community. These Public Safety Power Shutoffs (PSPSs), as they are called, can cause hardships and pose risks to vulnerable populations that depend on electric power to run life-saving equipment.

More information on the history and policies related to PSPSs can be obtained from the California Public Utilities Commission.

A windstorm also has the potential to displace residents, which may require the City or relief organizations to provide short-term and/or long-term shelters to accommodate these individuals, in addition to providing for other emergency response activities such as cleanup and repair. This has the potential to impact the City economically, as City funds would have to be tapped into to respond adequately to the needs of the impacted members of the community, in addition to the costs of cleanup and repair.

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SECTION 12: HAZARDOUS MATERIALS

WHY ARE HAZARDOUS MATERIALS A THREAT TO THE CITY OF SANTA MONICA?
Hazardous materials, if used incorrectly, can pose a hazard to human health and the environment.

Hazardous substances occur in chemicals like hydrocarbon fuels, chlorine, pesticides, and herbicides that are used daily and in large quantities by industrial, commercial, manufacturing and military facilities. Households and institutional facilities also use some of these chemicals for a variety of purposes. As a result of this widespread use, releases of these compounds into the environment, either accidentally or intentionally, occur often. According to the Environmental Protection Agency (EPA), nationally, the Federal government receives an average of 12 reports of releases of hazardous materials every day.0F
1 Similarly, and based on statistics compiled by the California Governor’s Office of Emergency Services1F
2 , more than 1,260 spills of hazardous materials were reported in California in 2023. In 2022 this number was approximately 1,200, and in 2021, 1,145. As of August 2024, the number of hazardous materials releases reported in the state was approximately 700. These same databases show that in the three full years mentioned above (2021, 2022 and 2023), Santa Monica reported between 17 and 27 leaks annually. Review of the data shows that more than 90% of these spills in Santa Monica are of sewage released from pipe laterals and mains that were damaged by tree roots or foreign matter (paper and baby wipes seem to be the main causes). Other spills reported in the city include gas leaks from damaged pipes, gasoline leaks from faulty gas dispensers, and oil sheens and tar balls reported at the beach.

Although most of these incidents appear to be more of a nuisance than a hazard, materials contained in sewage can pose a threat to human health and the environment, especially if allowed to flow into the storm drain system and eventually the ocean. Containment and cleanup of these spills, however, typically is completed within hours of first observed and reported with limited to no permanent damage. An earthquake, on the other hand, especially if on the Santa Monica fault, has the potential to result in dozens to hundreds of pipe ruptures, releasing natural gas, petroleum oil, and sewage.

Repair of all of the breaks can be anticipated to take weeks. Other hazardous material releases could also occur as a result of strong ground shaking. This report discusses earthquake-induced and transportation-related hazardous materials releases.

Past releases of hazardous substances from leaking underground storage tanks previously impacted the groundwater under Santa Monica, requiring extensive and costly treatment. More recently, researchers have also realized that some chemicals used for a variety of applications, such as stainand water-resistant fabrics and carpeting, cleaning products, paints, and fire-fighting foams, are very persistent in the environment and can pose a threat even if their release occurred decades ago. These substances, referred to as perfluoroalkyl and polyfluoroalkyl substances (PFAS), have recently been detected in groundwater pumped from some of the wells that service the city of Santa Monica. Both of these cases are also discussed further in this report.

1 https://www.epa.gov/emergency-response/emergency-response-and-recognizing-hazardous-substance-releases, accessed August 26, 2024. 2
https://www.caloes.ca.gov/office-of-the-director/operations/response-operations/fire-rescue/hazardousmaterials/spill-release-reporting/, accessed August 21, 2024.

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DEFINITIONS
What are Hazardous Materials?
According to the United States Environmental Protection Agency (EPA), hazardous materials consist of substances:

1. that may cause or significantly contribute to an increase in mortality or an increase in serious irreversible, or incapacitating reversible illness;

2. may pose a substantial present or potential hazard to human health or the environment when improperly treated, stored, transported, disposed of or otherwise managed; and

3. whose characteristics can be measured by a standardized test or reasonably detected by generators of solid waste through their knowledge of their waste.

Hazardous materials also have physical properties that make these substances corrosive, flammable, and/or reactive, and these properties can negatively impact human life and safety (EPA 40 CFR 260.10). In order for a substance to be classified as a hazardous material, it must contain a defined amount of toxic chemicals, with the levels for each compound defined by the EPA.

Because of the high demand for these chemicals, their transport, use, and storage are necessary, with these activities governed by a series of laws and regulations aimed at safely managing their use.

Laws and safety protocols have been and continue to be developed to ensure the safety of workers who have the potential to be exposed to hazardous materials. The Occupational Safety and Health Administration (OSHA) is responsible for setting and enforcing safety practices in the workplace, and also provides necessary training to help employers and workers be more aware of the health hazards posed by these chemicals and materials. To further define what hazardous materials are, OSHA and the U.S. Department of Transportation (DOT) have categorized them into nine classes2F 3 :

1. explosives, which include mass explosion, projectile hazard, minor projectile or fire, minor blast, insensitive explosives3F
4 , and very insensitive explosives,

2. compressed gases, which include flammable gases, nonflammable compressed gases, and poisonous gases,

3. flammable liquids, which include flammable liquids with a flash point below 141° F degrees,
and combustible liquids with a flashpoint between 141°
F and 200°F,

4. flammable solids, which include spontaneously combustible solids, and solids dangerous when wet,

5. oxidizers and organic peroxides,

6. toxic materials, which include materials that are poisonous and infectious agents,

7. radioactive materials, which are broken down into levels 1 through 3 based on the amount of radioactivity they release and the persistence (half-life) of the radioactive material,

8. corrosive materials, which are chemicals (such as acids and bases) that cause visible destruction of or irreversible alteration to living tissue (such as skin) at the site of contact, and have the ability to corrode steel at a rate of 0.25 inches per year, and

3 https://www.osha.com/blog/dot-hazard-classes accessed August-September 2024. 4 Insensitive munitions refer to materials used in war such as guns, ammunition, and bombs that are insensitive to stimuli, such as heat or shock, that could cause an unplanned explosive event (https://www.insensitivemunitions.org/history/introduction/ accessed August 26, 2024).

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9. miscellaneous, which are materials that present a hazard during shipment, such as lithium batteries and substances transported at elevated temperatures, but do not meet the definition of the other eight classes above.

What is a Hazardous Material Release?
A hazardous materials release is an “improper leak, spillage, discharge or disposal” of hazardous materials or substances” posing a significant threat to human health and safety and to the surrounding environment. Releases can be the result of an accident, or of intentional acts of criminality or terrorism.4F
5 Exposure to hazardous materials in the workplace, such as in a manufacturing facility that either generates or uses hazardous materials, is a serious issue and warrants oversight from company leaders and regulatory officials such as OSHA. Exposure in these situations, if a leak occurs, is generally localized and can be avoided with proper education and the enforcement of safety practices. However, hazardous materials are not limited to the bounds of factories, as they are transported from one location to another in vehicles, railroad cars, airplanes, ships, and in pipelines, and are used in a variety of locations including hospitals and other medical facilities, businesses (such as gas stations, dry cleaners, vehicle repair shops), and even in residential households. A hazardous material release could occur at any of these locations, with the potential to impact the health or well-being of individuals in the immediate area. The containment and clean-up of hazardous materials releases require specialized equipment and properly trained individuals. Some releases can be contained and cleaned up relatively quickly, at a cost of tens to thousands of dollars, whereas others require large-scale environmental remediation projects that can last decades and cost millions to hundreds of millions of dollars.5F
6 Conditions Conducive to Hazardous Material Releases
Hazardous substances are used in a variety of applications, often because they either work more effectively than their non-hazardous counterparts, or because there are no eco-friendly alternatives.

Thus, for example, today hospitals use radioactive substances to image the inside of our bodies and make illness diagnoses, and to treat certain diseases and tumors. Chlorine is highly effective in disinfecting water and non-porous surfaces and is thus used in water treatment facilities and as a cleaning compound. Prior to the advent of electric vehicles, gasoline- or diesel-powered cars dominated our roads and freeways, with leaded gas being the norm prior to the mid-1970s. Electric vehicles currently depend on lithium-ion batteries, and while these have a smaller environmental footprint than gas-powered vehicles, both the mining and disposal of lithium release hazardous materials onto the environment.

The types and amounts of hazardous substances have increased over time in response to an increased demand for products that use these materials. In decades past, “out of sight, out of mind” used to be the traditional approach to dealing with trash, sediment, fertilizer-laden irrigation water, used motor oil, unused paint and thinner, and other hazardous substances that people would dump onto the ground, or into the sewer and storm drains. Substances dumped into the storm drain system made their way into drainages, lakes, rivers, and the ocean, endangering aquatic organisms and wildlife dependent on these water sources, and impacting human health. Some substances dumped

5 https://www.dhs.gov/hazardous-materials-release, accessed September 5, 2024. 6 https://www.epa.gov/trinationalanalysis/releases-chemicals, accessed August-September 2024.

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onto the ground made their way into the groundwater, contaminating drinking water resources. Even if only the soils were contaminated by hazardous substances dumped onto the ground, these soils require cleanup, as contaminated soils are unacceptable as growing mediums for crops or as a foundation for buildings.

Partly in response to these past practices, both the Federal and California governments enacted legislation to manage the use, transport and disposal6F 7 of these substances. Some of these significant
legislations include the 1972 Federal Clean Water Act and the California Porter-Cologne Water Quality Control Act, the 1980 Comprehensive Environmental Response, Compensation and Liability Act (CERCLA), the 1986 Emergency Planning and Community Right-to-Know Act (EPCRA), the Resources Conservation and Recovery Act (RCRA), the Hazardous Materials Disclosure Program, the Hazardous Materials Incident Response, and the California Hazardous Material Spill/Release Notification Guidance. For detailed information regarding what each of these pieces of legislation cover, refer to the links provided, or Chapter 6 of the Technical Background Report to the City’s Safety Element.

The pieces of legislation listed above task the Environmental Protection Agency (EPA) and several other Federal, State and local agencies with the responsibility of regulating the handling of waste materials, and/or monitoring the releases of hazardous materials into the air, water or land. Air releases include emissions through confined airstreams such as stacks, pipes or ducts, and fugitive releases that are not confined. To manage air pollutants, the EPA and locally, the South Coast Air Quality Management District (referred to as the South Coast AQMD), have issued standards for emission levels, require the use of scrubbers and other methods to capture pollutants from industrial sources, and monitor air quality. Other efforts include stringent standards to reduce emissions from vehicles and engines, including the use of cleaner-burning fuels.7F 8 Water releases consist of discharges of hazardous materials into bodies of water such as streams, rivers, or ponds. Wastewater discharges from various industries and wastewater treatment plants, known as “point sources8F
9 ,” and from “non-point sources9F
10” are managed through the National
Pollutant Discharge Elimination System (NPDES). Locally, the agency responsible for establishing water quality standards and regulating the discharge of pollutants into State waters is the Regional Water Quality Control Board (RWQCB). All releases or threatened releases of hazardous materials need to be immediately reported to the local office of the RWQCB and the Governor’s Office of Emergency Services. Land disposal includes placing hazardous materials into landfills, injecting substances underground, and surface impoundments. Some standards for land disposal include the use of double liners in landfills, implementation of leak detection systems, and the collection and removal of leachate.

Through the efforts made by the EPA and its State counterparts, including the enactment of regulations and monitoring of known polluting sources, there has been a decrease in the overall amounts of hazardous materials released into the environment. Specifically, the EPA reports that between 2013 and 2022, releases of toxic chemicals from facilities covered in the Toxics Release

7 The use, generation, processing, production, packaging, treatment, storage, transport, emission, discharge, or disposal of a hazardous materials is collectively referred to as “handling” of a hazardous material. 8 https://www.epa.gov/haps/reducing-emissions-hazardous-air-pollutants 9 A point source is a discrete, easily identifiable source of pollution, such as a smokestack or sewer. 10 These are roadways, parking lots, yards, farms, and other non-discrete areas from where pollutants may be carried by rain and urban runoff into canals, rivers, and other bodies of water, and into the soil and groundwater.

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Inventory (TRI) program decreased by 21%, with a 26% decrease in air releases. Moreover, the TRI facilities reported that in 2022 they managed 88.5% of their chemical waste through recycling, energy recovery, treatment and similar practices, with only the remaining 11.5% of their chemical waste released into the environment.10F
11 Thus, although significant improvements have been made, there is still room for improvement. There are other forms of hazardous materials releases that do not occur often, or that occurred several years to decades ago, but whose impacts are still being managed through removal or remediation. These forms of release are described in general terms below. Further down in this section we summarize past releases of hazardous materials in the southern California region, and specific examples of recent past releases of contaminants in Santa Monica proper.

Releases from Leaking Underground Storage Tanks
Leaking underground storage tanks (LUSTs) have been recognized as contributors to groundwater contamination since the early 1980s. Leaks from underground storage tanks, even small leaks, allow gasoline compounds, solvents or other substances to migrate out and impact the surrounding soil.

Over time, driven by gravity and/or the infiltration of rain water, the leaked substances will make their way into the groundwater if the sediments are water-bearing. This contaminated groundwater then can make its way into municipal wells, which, if unrecognized, can have a critical impact on the health of those that depend on this water source. With the rising cases of contaminated water wells during the 1980s, programs and regulations were developed to remove damaged underground storage tanks, clean up the contaminated soils and groundwater, and install new storage tanks and leakage monitoring systems to reduce the potential for future leaks.

Spills Related to Transportation Accidents
Large quantities of hazardous materials are transported daily in the United States. Although most deliveries reach their destination safely, incidents do occur. According to data collected and compiled by the U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration, in 2023, 8,437 hazardous materials incidents occurred during transit in U.S. highways, with more than 200 of those occurring in California. These incidents resulted in 12 fatalities, 14 hospitalized injuries, 50 non-hospitalized injuries, and damages of more than $39 million. Nearly twice as many incidents (15,858) occurred loading, unloading, and during in-transit storage of hazardous materials, but all of these other incidents combined caused a total of 23 injuries (5 requiring hospitalization), no fatalities, and less than $10 million in damages. The figures for 2023 are typical of the past ten years, with the annual number of in-transit incidents between 2015 and 2023 ranging between about 4,700 and 8,500, and damages amounting to between $35 million and nearly $1 billion.11F
12 These costs do not include the economic and personal disruption resulting from immobilized traffic and/or evacuation of businesses and homes near the site of the incident.

Hazardous materials releases that occur as a result of vehicular accidents include spills of fluids from the vehicles involved (gasoline, diesel, battery acid, hydraulic fluid, etc.), the cargo itself, or a combination of both.12F
13 The cargo materials that are most often involved in transportation incidents are flammable-combustible liquids and corrosive materials.

11 https://www.epa.gov/newsreleases/toxic-chemical-releases-have-declined-21-10-years-according-new-toxicsrelease, accessed in August-September, 2024. 12 https://www.phmsa.dot.gov/hazmat-program-management-data-and-statistics/data-operations/incident-statistics, accessed September 9, 2024. 13 https://ops.fhwa.dot.gov/publications/fhwahop08058/fhwahop08058.pdf Local Hazard Mitigation Plan Section 12
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All transportation of hazardous materials needs to be conducted under strict protocol in accordance with requirements set forth by the Department of Transportation (DoT) and spelled out in the Federal Code of Regulations (CFR) Title 49, Parts 171-180. Vehicles carrying hazardous materials are required to have placards that indicate at a glance the chemicals being carried, and whether or not they are corrosive, flammable or explosive. Safety data sheets (SDSs) for each substance being transported need to be carried by the conductor. These SDSs are designed to help emergency response personnel identify the most appropriate action to contain the specific substances involved in the spill, should one occur. In California, the California Highway Patrol is in charge of spills that occur in or along freeways, with Caltrans, the local fire departments and local sheriffs providing additional resources as needed.

Releases Due to Damaged Pipelines
Pipelines are used to transport a variety of hazardous materials including crude oil, refined petroleum products and other petrochemicals, and natural gas and other gases. If a pipeline carrying hydrocarbon liquids (such as crude oil or gasoline) breaks or springs a leak, the liquid released can pose a variety of risks to the environment and to the population adjacent to the section of damaged pipeline. Specifically, hydrocarbon liquids can contaminate the surrounding soil and nearby surface waters, and could potentially impact the groundwater also. Vapors associated with these substances, if heavier than air, can collect in and displace the oxygen in low or enclosed areas. If people or animals are trapped in those low-lying areas, they could asphyxiate. Hydrocarbon vapors can also be flammable or combustible, and are often mixed with other chemicals that are also hazardous.

Exposure to a hydrocarbon product released from a damaged pipeline can be by a variety of pathways, including inhalation, ingestion, skin absorption, and skin or eye contact. Other products transported via pipelines may be volatile and extremely flammable (such as aviation gasoline), extremely irritant to skin, eyes, and lungs (such as anhydrous ammonia), and toxic or highly corrosive (such as hydrogen sulfide).

Pipeline operators are responsible for the continuous maintenance and monitoring of their pipelines to evaluate and repair, when necessary, corroded sections of pipe that no longer meet pipelinestrength criteria. All excavations or drilling operations near pipelines, or anywhere else, for that matter, should be conducted only after proper clearance has been provided by the appropriate utility agencies or companies. California law requires that all excavations be cleared in advance. This is done locally by Underground Service Alert of Southern California, also referred to as DigAlert.

Their telephone number is 8-1-1. Calls need to be made at least two (2) working days (48 hours) before digging, and the proposed excavation area needs to be delineated or marked.

Pipelines can be damaged during an earthquake, often the result of permanent ground deformations, including fault rupture, liquefaction, landslides, and consolidation of loose granular soils. Tectonic uplift or subsidence can also impact a pipeline by either breaking it, or changing its gradient, which can lead to reversals in flow of the substance inside. Seismic shaking typically has less of an impact on buried utilities than it does on aboveground structures, but leaks, especially at pipe joints or welds, have been reported in past earthquake events.13F 14 14 For a report with additional references on seismic shaking-induced damage to pipes, refer to https://www.researchgate.net/publication/226844920_Estimation_of_Earthquake_Damage_to_Buried_Pipelines_C aused_by_Ground_Shaking
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Releases Due to Earthquakes
Isolated unauthorized or accidental releases of hazardous materials can occur at any time, but earthquakes have the potential to cause several incidents at the same time. Strong seismic shaking can lead to the release of hazardous materials by damaging storage facilities and transport infrastructure. During an earthquake, chemical storage tanks could buckle or, if improperly secured and fastened, could easily be punctured and/or tipped over. Improperly segregated chemicals could react forming a toxic gas cloud. Even small amounts of chemicals, if kept in breakable containers and stored together (like in the same chemical closet at a high school chemistry lab or the same aisle at the grocery store), could result in a potentially hazardous situation if the containers break and the chemicals react with each other. As mentioned above, pipelines are especially vulnerable to seismic damage as they can be pulled apart or ruptured by strong ground motion and surface ground deformation. Crude oil and natural gas lines pose a significant hazard due to the high number of pipelines in urban environments and because leaks from ruptured lines can lead to secondary fires.

A key point to remember regarding the management of hazardous materials spills in the aftermath of an earthquake is that it is substantially more difficult to do so than under non-earthquake conditions. Hazardous material response teams responding to a release as a result of an earthquake have to deal with potential structural and non-structural problems of the buildings housing the hazardous materials, potential leaks of natural gas from ruptured pipes, and/or downed electrical lines or equipment that could create sparks and cause a fire. When two hazards with potentially high negative consequences happen at the same time, the challenges of managing each are greatly increased. During an earthquake response, hazardous material emergencies become an additional threat that must be integrated into the response management system.

Inappropriate or Accidental Use of Hazardous Materials in Households Households use significant quantities of chemicals and hazardous materials that can pose a health hazard and can be damaging to the environment. Products such as detergents, bleach, furniture polishers, oven cleaners, bathroom cleaners, medicines, cosmetics, and bug repellants and poisons contain hazardous substances that can be toxic, corrosive, reactive or flammable. Other products often found in homes, such as batteries, paint products, and solvents, can be corrosive, reactive, or explosive.

These products are generally safe when used in accordance with the directions on their labels, but can be hazardous if used or disposed of inappropriately. A common issue is when different cleaning products (such as bleach and ammonia) are mixed together or applied to a surface at the same time, and the chemical reactions produce gases that cause acute inflammation of the nose and lungs, burn the skin, and/or irritate the eyes. Cleaning products can also impact indoor air quality by producing irritating vapors (volatile compounds) that can cause or aggravate asthma, allergies, and other respiratory ailments. Many cleaning products are dangerous, even potentially fatal, if ingested, as evidenced by the thousands of children, teens and older adults that have been admitted to hospitals in the past decade after ingesting laundry pods either accidentally, or as a result of a dare.14F 15 The U.S. Fire Administration reports that an average of about 1,700 fires in homes occur annually as a result of chemical reactions or spontaneous combustion.15F 16 Solvents and oils used to clean or

15 https://en.wikipedia.org/wiki/Consumption_of_Tide_Pods; accessed October 10, 2024. 16 https://www.usfa.fema.gov/prevention/home-fires/prevent-fires/home-hazardous-materials/; accessed October 10, 2024.

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refinish furniture are known to be especially prone to spontaneous combustion. Lithium-ion battery fires are becoming increasingly common. In New York City, damaged or overheated lithium-ion batteries have become a prime source of house fires, prompting the City to enact a series of regulations aimed to increase the safety of the lithium-ion batteries that power the ubiquitous ebikes and e-scooters.16F 17 The improper disposal of hazardous materials can also have negative health consequences for sanitation workers and other members of the community if exposed to these substances, in addition to causing damage to the environment. Thus, all unused and unwanted hazardous materials should be disposed of at a hazardous waste disposal facility. Chemicals should never be dumped down the toilet, drains, or sewage, and should not be burned in open dumps or incinerators.

HISTORICALLY AND LOCALLY SIGNIFICANT SOUTHERN CALIFORNIA

RELEASES OF HAZARDOUS MATERIALS
Historically, there have been many releases of hazardous materials in the southern California area.

Most of these releases are due to human actions, however, some of the larger releases have occurred due to natural causes such as earthquakes. Some of the more significant releases reported in southern California are listed below, with an emphasis on earthquake-related releases going back several decades, and transportation releases during the past five years. The list also includes a summary of the hazardous material spill reports compiled and reported by the Governor’s Office of Emergency Services for the years between 2021 and June 2024 for the city of Santa Monica. 1987 Releases Related to the Whittier Narrows Earthquake The magnitude (M) 5.9 Whittier Narrows earthquake struck on October 1, 1987 (see Section 6).

There was a total of thirty emergency releases of hazardous materials reported as a result of this earthquake. One of the most significant releases involved leakage of about two-thirds of a 1-ton container of chlorine at a facility in Santa Fe Springs. Another significant release occurred at the California State University, Los Angeles Campus; this involved the spillage of several chemicals that resulted in structural fire, and asbestos contamination. Southern California Gas also reported a total of 1,411 natural gas line breaks.
1994 Releases Related to the Northridge Earthquake
The M 6.8 Northridge earthquake struck early in the morning on January 17, 1994. Sixty emergency releases of hazardous materials occurred as a result of this moderate earthquake, however, most of them were not covered by the news media. One of the most significant releases of hazardous materials was the result of a section of railroad track that was displaced approximately 4 inches, causing a train to derail. A total of 29 train cars were involved in the derailment; 13 of the cars carried sulfuric acid, and one of them spilled 2,000 gallons of the compound. Sulfuric acid is a highly corrosive substance that can cause severe skin burns, irritate the eyes potentially causing blindness, impact the nose and lungs causing breathing difficulties if inhaled, and damage to internal organs if ingested. In concentrated form it can also be potentially explosive. Additionally, 1,000 gallons of diesel fuel spilled from the derailed train. Petroleum oil pipelines and natural gas lines

17 https://www.nytimes.com/2024/10/03/nyregion/e-bike-lithium-battery-fires-safety-nyc.html#; accessed October 10, 2024.

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were also affected by this earthquake. Roughly 230,000 gallons of oil were spilled and 752 natural gas lines broke as a result of this seismic event.
2019 405-Freeway Closure due to Overturned Truck
Early in the morning on March 10, 2019, the driver of a propane truck lost control of his vehicle, crashed into the center divider, and rolled the truck over onto its side. This occurred on the I-405 South, just south of the Burbank Boulevard on-ramp. All northbound and southbound lanes were closed for approximately 6 hours. During this time, the truck was lifted to its upright position and the propane was offloaded into another truck.17F
18 2020 405-Freeway Closure due to Hazardous Spill
On January 23, 2020, a package containing hazardous materials fell off of a truck traveling on the I-405 near Inglewood, California. All northbound and southbound lanes of the freeway were closed while officials determined the contents of the spill and cleaning crews removed the hazardous material. The freeway closure lasted for approximately 4 hours between 11 AM and 3 PM.18F 19 2020 Hazardous Material Spills
In 2020, the California Governor’s Office of Emergency Services reported a total of 1,166 spills in Los Angeles County, with 20 occurring in the city of Santa Monica. Twelve of these incidents involved spills of sewage from damaged mains and laterals. Four of the incidents reported were for leaks of natural gas from damaged pipelines, with the damage typically caused by post-diggers or backhoes. Two of the incidents involved callers reporting tar balls at the beach, in one case spread over a relatively large (approximately 1-square-mile) area. One incident involved the potential release of diesel fuel from a water craft that ran aground, and one incident involved a truck bottoming out, damaging its fuel tank in the process and releasing an estimated 200 gallons of diesel onto the soil.
2021 Hazardous Material Spills
In 2021, the California Governor’s Office of Emergency Services reported a total of 1,144 spills in Los Angeles County, with 25 occurring in the city of Santa Monica. A large percentage of the incidents in Santa Monica (21 out of 25) involved releases of sewage onto roadways, alleys, parking lots, and in a few cases, storm drains, due to blockages to the sewer mains or laterals. One incident involved an unknown chemical that the caller reported had been “spilled in the garage of their apartment building” and had melted their tires when they drove through it. Another incident was related to an unknown individual dumping an unknown amount of oil into a drainage ditch, which, according to the caller, had been going on for at least six months prior to the call. The type of oil was unknown although the database reports it as petroleum-based. A natural gas leak occurred in April 2021 when a boring machine struck a 16-inch steel main gas line while installing communication wires. The gas leak required the mandatory evacuation of two residential buildings; closure of several road sections while the leak was contained and the pipe was repaired; and the multi-day power outage prompted the voluntary evacuation of residents of several nearby blocks (see Figure 12-1 and Photos 12-1 and 12-2). This incident resulted in the activation of the City’s Emergency Operations Center to coordinate multi-department and utility agency response and

18 https://lafd.org/news/propane-tanker-overturns-405-freeway-sherman-oaks; accessed in June 2024. 19 https://patch.com/california/redondobeach/405-freeway-shut-down-due-hazmat-spill; accessed in June 2024.

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resident assistance. Lastly, one of the incidents involved the report of an oil sheen and numerous tar balls washing up on the shore.

Figure 12-1: Map of the impacted area where a
multi-day power outage was required to
complete repairs to the gas main break. Actual
damage occurred on Lipton Avenue at Stanford
Street.

Photo 12-1: View to the northwest along
Stanford Street, from just south of Lipton
Avenue, of the street closures and potholing
required to fix the gas main.

Photo 12-2: View of damaged gas main under repair.
2022 Hazardous Material Spills
In 2022, the California Governor’s Office of Emergency Services reported a total of 1,207 spills in Los Angeles County, with 27 occurring in the city of Santa Monica. All but four of these spills were related to damaged sewer lines that released raw sewage onto the streets and/or nearby storm drains.

Two of the spills reported were for damage to gas lines; one caught fire and required the evacuation of two nearby buildings, the other required the evacuation of approximately 100 people and closure of the street until the gas line was fixed. Another leak was associated with the failure of an electric transformer during a storm, releasing petroleum product that, because of the rain, flowed into an adjacent storm drain. One call was for tar balls and oil sheen observed at the beach. 2023 Hazardous Material Spills
In 2023, the California Governor’s Office of Emergency Services reported a total of 1,266 spills in Los Angeles County, with 17 occurring in the city of Santa Monica. Twelve of the leaks reported Local Hazard Mitigation Plan Section 12
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were for sewage released from damaged sewage mains or laterals; most of these leaks amounted to no more than 500 gallons of sewage. One incident involved the release of about 10,000 gallons of sewage onto a bike path and sand landscape as a result of multiple pump failures. One incident involved the report of tar balls washing up on the beach, and another report was filed by a resident who observed dark colored oil (petroleum) at the beach. Finally, one incident was related to the mechanical failure of a shaft releasing about 2 tablespoons of petroleum-based server oil into Santa Monica Bay.

July 2024 Closure of I-15 due to Truck Fire
Early in the morning of Friday, July 26, 2024, a truck transporting six industrial-grade lithium-ion batteries on the back of a trailer crashed, causing the batteries to catch fire. Considering the potential danger of this fire, California Highway Patrol initiated a “hard” closure of interstate 15 (I-15) between Barstow and Baker. All northbound and southbound lanes were closed. Hazmat cleaning crews worked tirelessly to remove the hazardous material. The I-15 opened once again early Sunday morning, causing this shutdown to last approximately 48 hours.19F 20 The highway closure severely
impacted travel times for those travelling north or south on the I-15. 2024 Hazardous Material Spills
Between January and July of 2024, the California Governor’s Office of Emergency Services reported a total of 703 spills in Los Angeles County, with 11 occurring in the city of Santa Monica. Six of these incidents were related to leaks of raw sewage from damaged mains or laterals. One of the incidents was for an unusually large number of tar balls of different sizes washing up onto the beach.

Another incident involved a vehicular crash onto a gas meter, releasing natural gas. Residents from 12 houses in the area were evacuated while repairs were conducted by Southern California Gas. A business on Colorado Avenue discovered that water from an unknown source had been collecting in a subterranean pit designed to collect and pump rainwater from their underground parking structure. The water was chemically tested and found to contain solvents (trichloroethylene [TCE] and tetrachloroethene [PCE}). The water, which had previously been released to a storm drain, was to be collected into a 20,000-gallon tank while a more permanent solution was implemented. The remaining two incidents included the release of 5 to 10 gallons of gasoline onto the floor of a gas station while a customer was re-fueling their vehicle, and the report of an oil caddy under a vehicle leaking onto the asphalt. In both of these cases, the leaks were contained with sand bags and absorbent pads, and kitty litter was used to clean up the spills.

September 2024 Freeway Closure due to Truck Fire
On September 26, 2024, a truck carrying a load of lithium-ion batteries overturned on the 47 Freeway at Navy Way, east of the Vincent Thomas bridge on Terminal Island. The lithium batteries ignited, with the resulting fire forcing the closure of the freeway and bridge for more than 30 hours.

Firefighters eventually moved the rig container with the burning batteries to an open lot near the Los Angeles Fire Department Station 40 on Terminal Island, where the batteries were allowed to burn out. Lithium battery fires run exceptionally hot and require very large amounts of water to extinguish.

Water was not used in this case in an effort to not spread hazardous materials into the waterways or other areas. This incident had a significant impact on Port of Los Angeles operations, with several terminals closed for more than 24 hours.

20 https://www.8newsnow.com/news/local-news/truck-fire-hazmat-situation-closes-i-15-between-las-vegas-losangeles/ Local Hazard Mitigation Plan Section 12
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HAZARDOUS MATERIALS RELEASE ASSESSMENT FOR SANTA MONICA Hazard Identification
The primary concerns associated with a hazardous materials release are both the short- and longterm impacts to the public from exposure to the hazardous substance(s) that was released. The shortterm impacts are particularly concerning if the substance released is a toxic gas at normal temperatures and pressures. Long-term concerns are associated with substances that could impact the area’s groundwater resources, especially substances that do not break down quickly and accumulate both in the environment and in organisms (environmentally persistent). Thus, the first step in the effective management of hazardous substances is to know which businesses or facilities generate, use, store or transport hazardous materials, and the types and quantities of substances that are being generated, used, stored or transported in the City. This is discussed further in the following subsections.

Then, the best way to reduce the risk posed by a hazardous material release is the proactive enforcement of the stringent regulations that have been developed by both Federal and State governments governing the manufacturing, storage, transport, and use of hazardous materials. The city of Santa Monica, like all of Los Angeles County, observes the most current version of the California Fire Code (currently the 2022 edition that became effective on January 1, 2023) for the handling of hazardous materials. Risk minimization actions often used include secondary containment; segregation of chemicals to reduce reactivity during a release; sprinkler and alarm systems; monitoring, venting and auto shutoff equipment; and treatment requirements for toxic gas releases. The Santa Monica Fire Department conducts compliance inspections of regulated facilities on an annual basis.

Generators of Hazardous Materials
Given that knowledge of the substances being used is of paramount importance, all businesses that handle more than a specified amount of hazardous materials, a mixture containing hazardous materials, or extremely hazardous materials are required to submit a Hazardous Materials Business Plan (HMBP) to the local Certified Unified Program Agency (CUPA). The CUPA with responsibility for the City of Santa Monica is the Santa Monica Fire Department (SMFD). The reportable quantities or types of hazardous materials that trigger the requirement for a HMBP are listed below:
• Any business that at any one time in the course of a year uses, generates, processes, produces, treats, stores, emits, or discharges a hazardous material in quantities at or exceeding:
 55 gallons or more of a liquid;
 500 pounds or more of a solid; or
 200 cubic feet (compressed) of gas
• Any business that handles, stores, or uses Category (I) or (II) pesticides, as defined by the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA), regardless of amount. • Any business that handles Department of Transportation (DOT) Hazard Class 1 (Explosives, as defined in Title 49 of the Code of Federal Regulations) regardless of amount. • Any business that handles extremely hazardous substances in quantities exceeding the threshold planning quantity, as listed in Title 40 of the Federal Code of Regulations, Part 355. • Any business subject to the EPCRA (also known as SARA Title III). Generally, EPCRA includes facilities that handle hazardous substances above 10,000 pounds, or extremely hazardous substances above threshold planning quantities. Some exceptions include retail gas stations with Local Hazard Mitigation Plan Section 12
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up to 75,000 gallons of gasoline or 100,000 gallons of diesel if their underground storage tanks meet the 1998 upgrade requirements.
• Any business that handles radioactive materials in quantities for which an emergency plan is required to be adopted, pursuant to Parts 30, 40 or 70 of Chapter 10, Title 10, Code of Federal Regulations (CFR), or pursuant to any regulations adopted by the State in accordance with those regulations.

All HMBPs need to be certified and/or updated annually, by September 1st of each year, with plans submitted electronically, or within 30 days of a change in inventory, any change in site conditions that would impact emergency response, a change in business location or mailing address, a change in the emergency contact person, change of ownership, or a change in business name. HMBPs are required to provide, at a minimum, the following information, and all businesses that handle hazardous materials must have a copy of their plan readily available onsite:
1) The business owner/operator, and 24/7 contact information for key personnel 2) Description of the business activities conducted at the facility 3) Inventory of the hazardous materials used at the facility 4) A site map that depicts hazardous materials handling and storage areas, loading areas, internal roads, adjacent streets, storm and sewer drains, access and exit points, emergency shutoffs, evacuation staging areas, and location of emergency response equipment. The site map should depict this information in a Cartesian frame of reference, or at least state where north is relative to the facility.
5) The emergency response plans and procedures, including contingency plans, if any, to be implemented in the event of a reportable release or threatened release of a hazardous material 6) Employee training plans and documentation that employees have been trained in safety procedures in the event of a release or threatened release of a hazardous material. All new employees need to be trained, and existing employees need to take annual refresher courses.

Information regarding potential chemical hazards in the area can be obtained from the City’s CUPA, and from the EPA, per the requirements of the Federal Emergency Planning and Community RightTo-Know Act (EPCRA) of 1986, and the Resources Conservation and Recovery Act (RCRA). In accordance with the EPCRA, manufacturers are required to report to the EPA the release of any of more than 600 designated toxic chemicals to the air, soil or water. Manufacturers are also required to report the off-site transfer of waste for treatment or disposal at another facility. This information is maintained and published by the EPA so that communities can prepare to respond to chemical spills, hold companies accountable, and make informed decisions as to how these chemicals are being handled. This list is referred to as the Toxics Release Inventory (TRI). There is only one facility in the city of Santa Monica that is listed in the TRI. This facility is Associated Ready Mixed Concrete, Inc. (see Table 12-1), and the waste that this business handles via recycling is lead and lead compounds.

The RCRA is the principal Federal law that regulates the generation, management and transportation of hazardous waste. Facilities or businesses that produce hazardous waste are generally classified based on the quantity of hazardous waste being produced. A small quantity generator as a facility that produces between 100 and 1,000 kilograms (Kg) of hazardous waste per month (approximately equivalent to between 220 and 2,200 pounds, or between 27 and 275 gallons). A “conditionally exempt” small quantity generator is a business that generates 220 pounds (27 gallons) or less of Local Hazard Mitigation Plan Section 12
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hazardous waste per month. Since some of these facilities are often small, start-up businesses that come and go, the list of small-quantity generators in a particular area typically changes over time.

Sometimes, a facility remains, but the name of the business changes with new ownership. These facilities may include dry cleaners, auto repair shops, medical/dental facilities, hospitals, schools, and metal plating shops. The most recent (June 2024) list of small-quantity generators in the city of Santa Monica included 181 sites. These facilities are not listed on Table 12-1.

Facilities that produce over 1,000 Kg (2,200 pounds or about 275 gallons) of hazardous waste per month are large-quantity generators. If a large-quantity generator produces, transports or stores waste that can cause harm to humans or the environment, then the facility is fully regulated under RCRA.

Waste that does not meet these criteria is not classified as hazardous, but it is still subject to certain management requirements. As of June 2024, there were five facilities in Santa Monica that were listed as RCRA large-quantity generators, and 30 sites that were listed as non-RCRA large quantity generators. These sites are listed on Table 12-1 and are shown on Figure 12-2. Significantly, there are no known abandoned hazardous waste sites in the city of Santa Monica (referred to as Superfund sites).

Table 12-1: TRI Site, and Large-Quantity Generators (LQGs) of Hazardous Materials in the City of Santa Monica
Facility Name; Street Address Zip Code EPA ID Type Facility Associated Ready Mixed Concrete, Inc.; 1620 19th Street CAL000378724 TRI Annenberg Community Beach House;
415 Pacific Coast Hwy. CAC002639258 RCRA LQG
Kite Pharma (formerly Agensys, Inc.); 1800 Stewart St. CAL000361097 RCRA LQG BVA; 1522 Broadway Ave. CAD981440654 RCRA LQG
Courtesy Cleaners; 720 Montana Ave. CAD981581523 RCRA LQG CVS Pharmacy #3903; 3202 Wilshire Blvd. CAR000232496 RCRA LQG CVS Pharmacy #9608; 2505 Santa Monica Blvd. CAR000229468 RCRA LQG CVS Pharmacy #11178; 500 Wilshire Blvd. CAR000303321 RCRA LQG CVS Pharmacy #9726; 1411 Lincoln Blvd. CAR000032474 RCRA LQG MOOZCOMP; 1639 Euclid St. CAP000323709 RCRA LQG
Pioneer Magnetics; 3122 Nebraska St. CAD981667843 RCRA LQG Rite Aid #5490; 2412 Pico Blvd. CAL000380425 RCRA LQG
Providence Saint John’s Health Center; 1328 22nd St. CAD072945850 RCRA LQG Santa Monica Audi; 1020 Santa Monica Blvd. CAD133604967 RCRA LQG Santa Monica Business Park Watt; 2716 Ocean Park Blvd. CAR000181339 RCRA LQG Santa Monica Fire Station #2; 222 Hollister Ave. CAD981570500 RCRA LQG Santa Monica Service Center; 1721 22nd St. CA0000562140 RCRA LQG Santa Monica - UCLA Medical Center; 1250 16th St. CAL000213704 RCRA LQG Seritage Growth Properties; 302 Colorado Ave. CAP000302836 RCRA LQG Target Store T3338; 1610 Wilshire Blvd. CAR000109470 RCRA LQG Target Store T3344; 420 Broadway CAR000318709 RCRA LQG
Tesla Santa Monica; 1100 Colorado Ave. CAR0000172228 RCRA LQG Volkswagen Santa Monica Inc.; 2440 Santa Monica Blvd. CAD066237082 RCRA LQG Vons 2002; 1311 Wilshire Blvd. CAE000243535 RCRA LQG
Big Blue Bus Maintenance Facility; 1660 7th St. CAD981461312 Non-RCRA LQG Fleet Maintenance - City Yard; 2500 Michigan Ave Bldg. 5 CAD981461254 Non-RCRA LQG Honda Santa Monica; 1337 Euclid St. CAL000447293 Non-RCRA LQG Jaguar Land Rover Santa Monica; 3300 Olympic Blvd. CAL000461319 Non-RCRA LQG Jiffy Lube #1379; 2344 Pico Blvd. CAL000274398 Non-RCRA LQG Local Hazard Mitigation Plan Section 12
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Facility Name; Street Address Zip Code EPA ID Type Facility Lexus Santa Monica; 1631 9th St. CAL000334024 Non-RCRA LQG Pep Boys #1672; 2411 Pico Blvd. CAL000388519 Non-RCRA LQG Santa Monica Buick GMC; 1717 Santa Monica Blvd. CAL000448518 Non-RCRA LQG Santa Monica Community College General Campus;
1900 Pico Blvd. CAD038735049 Non-RCRA LQG
Santa Monica Ford; 1402 Santa Monica Blvd. CAD981395312 Non-RCRA LQG Santa Monica Motor Group; 3219 Santa Monica Blvd. CAL000462924 Non-RCRA LQG Santa Monica Municipal Airport;
3223 Donald Douglas Loop South CAL000200560 Non-RCRA LQG Subaru of Santa Monica; 1229 Santa Monica Blvd. CAL000409548 Non-RCRA LQG Toyota of Santa Monica; 801 Santa Monica Blvd. CAL000263933 Non-RCRA LQG Valvoline Instant Oil Change GN0021;
1757 Lincoln Blvd. CAL000370607 Non-RCRA LQG
Volvo of Santa Monica; 1631 Santa Monica Blvd. CAL000360347 Non-RCRA LQG W.I. Simonson Mercedes Benz; 1330 Colorado Ave. CAL000300358 Non-RCRA LQG Sources: EPA’s database search for Large-Quantity Generators (LGQ) in the city of Santa Monica (https://rcrapublic.epa.gov/rcrainfoweb/action/modules/hd/handlerindex and https://siteportal.calepa.ca.gov/nsite/map/help) based on a database search performed on June 26, 2024 and City staff input regarding some sites that are no longer active.

Information on non-RCRA sites in Santa Monica provided by D. Bernhard from the City of Santa Monica (personal communication, July 8-9, 2024).

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Leaking Underground Storage Tanks (LUSTs) and Cleanup Program Sites Historically, leaking underground storage tanks (LUSTs) were one of the primary causes of groundwater contamination by gasoline compounds and solvents. These leaks were typically the result of corroded single-walled steel tanks fitted with pipes that easily detached from the tanks, and lacked monitoring devices that could have alerted gas station operators if the tanks were leaking.

During the late 1990s and early 2000s, significant amounts of gasoline additives (Methyl tert-Butyl Ether [MTBE] and tert-Butyl Alcohol [TBA]) derived from LUSTs at various gasoline stations were detected in water pumped from several of the groundwater wells in the Charnock Subbasin that provide drinking water to the city (City of Santa Monica Annual Water Quality Report, 2022). When the contaminants were first detected in 1996, the City was forced to cease production from the impacted wells and rely instead primarily on imported groundwater while the contaminated groundwater was remediated. Industrial contamination was also detected in the Olympic wellfield.

In 2006, the City reached a settlement with the responsible parties, and in 2010, the City established a groundwater monitoring program that tests on a quarterly basis the City’s groundwater for a variety of chemicals. The impacted wells are now back in production.

Cleanup of LUST-impacted sites is a long and expensive process. In cases where only the soil is contaminated, the stained soil is generally excavated and replaced with clean soil, and the contaminated soil is shipped to a facility that accepts hazardous materials. The best remediation technique for groundwater depends on the type and extent of the contamination, and the aquifer impacted. In general, however, contaminated groundwater is either extracted and disposed of at a facility that can treat the contaminants, pumped and treated onsite, or remediated with in-situ techniques. Progress on these cleanup efforts for individual sites can be obtained from the Statewide inventory of LUSTs called GeoTracker, an online database maintained by the California Regional Water Quality Control Board (CRWQCB) in cooperation with the Governor’s Office of Emergency Services. The LUSTs listed in GeoTracker consist almost entirely of fuel-contaminated sites which are regulated pursuant to Title 23 of the California Code of Regulations, Chapter 16, Article 11. As of July 10, 2024, Geotracker listed eight (8) open and 114 closed LUST cases in the city of Santa Monica. Of the eight (8) open sites in the LUST database, three (3) are in the remediation phase, three (3) are in the site assessment phase, one (1) is in the verification monitoring phase, and one (1) is eligible for closure. The eight (8) open cases are listed in Table 12-2, and their approximate locations are shown on Figure 12-2.

As of July 10, 2024, Geotracker also listed 16 open and six (6) closed cleanup program sites in the city of Santa Monica. Cleanup Program Sites include all "non-federally owned" sites that are regulated under the State Water Resources Control Board's Site Cleanup Program and/or similar programs conducted by each of the nine Regional Water Quality Control Boards. Cleanup Program Sites are varied and include but are not limited to pesticide and fertilizer facilities, rail yards, ports, equipment supply facilities, metals facilities, industrial manufacturing and maintenance sites, dry cleaners, bulk transfer facilities, refineries, mine sites, landfills, RCRA/CERCLA cleanups, and some brownfields. Unauthorized releases detected at Cleanup Program Sites are highly variable and include but are not limited to hydrocarbon solvents, pesticides, perchlorate, nitrate, heavy metals, and petroleum constituents, to name a few. The open cleanup program sites in the city of Santa Monica are listed in Table 12-2, and their approximate locations are shown on Figure 12-2.

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Table 12-2: Open Leaking Underground Fuel Tank (LUST) and Cleanup Program Sites in the City of Santa Monica Site Name Address Site Type State Case No.
or Global ID Case Type Status, Contaminant
Date Leak
Discovered
0BArco #1946 332 Pico Blvd. LUST Site T0603739924 G 3, P 4/15/2005 Argo Realty Property 1661 Lincoln Blvd. LUST Site T0603701383 G 3, G 11/2/1987 Bonus Car Wash 2800 Lincoln Blvd. LUST Site T0603701428 G 3, G 6/30/1989 Snyder Diamond 1399 Olympic Blvd. LUST Site T10000001526 G 7, D, G 8/5/2009 Former Auto Repair Facility 1818-1824 Lincoln Blvd. LUST Site T10000019936 G 2, G 7/5/2022 Former Let Em’ Eat Cake Facility 1804 Lincoln Blvd. LUST Site T10000019937 G 2, G 7/6/2022 World Oil Station No. 16 and
Chevron #9-9266 1801 & 1732 Lincoln Blvd. LUST Site T10000013826 U 2, G 12/3/2019 Shell Service Station 1866 Lincoln Blvd. LUST Site T0603708873 G 5, G 3/9/2004 1501 Wilshire Blvd 1501 Wilshire Blvd Cleanup Program Site T100000011925 U 2, U 6/13/2018 1BBoeing Co. 3000 Ocean Park Blvd. Cleanup Program Site SLT4307472 S, G 4, P (TCE) 9/1/1998 Hallmark Cleaners 1907 Wilshire Blvd. Cleanup Program Site T10000011533 S 4, P (PCE) 4/9/2018 Verizon Santa Monica Plant Yard (AKA
Former Boeing/Douglas Plant – A7) 2902 Exposition Blvd. Cleanup Program Site SLT4307573 S, G, O 4, G, P 2/2/1998 Bergamot Property 2500 Olympic Blvd. Cleanup Program Site SLT4130A2335 S, G 6, P 1/2/1965 Metropolitan Cleaners 2003 Lincoln Blvd. Cleanup Program Site T0603701424 G 6, S 12/27/1987 Neighborhood Storage Associates, LLC 1707 Cloverfield Blvd. Cleanup Program Site SL0603767271 G 8, P (TCE) 9/27/2004 Olympic Well Field Area 1681 26th St. Cleanup Program Site T10000006812 U 3, P 5/7/2015 Water Garden Phase I and II 2300 Olympic Blvd. Cleanup Program Site SLT4130F2842 U 6, P (VOCs) 12/7/1998 CSHV Pen Factory LLC –
Buildings I, III, & IV Reuse 1681 26th St. Cleanup Program Site T10000006811 S, G 3, P 5/7/2015 Bon Voyage Auto 2319 Michigan Ave. Cleanup Program Site T10000012506 U 2, P 6/14/2018 Centercal Property 1921-1933 Wilshire Blvd. Cleanup Program Site T10000017536 S 2, P (PCE) 12/2/2021 Dry Clean Xpress 2611 Lincoln Blvd. Cleanup Program Site T10000020099 U 2, U 10/8/2015 House of Billiards 1901 Wilshire Blvd. Cleanup Program Site T10000017492 S 2, P 6/19/2017 Pacifica Equities, LLC 1639 11th St. Cleanup Program Site T0603746434 S 2, D, P 10/25/2005 Wilshire Cleaners 2420 Wilshire Blvd. Cleanup Program Site T10000011947 U 9, U 6/15/2018 Source: GeoTracker (https://geotracker.waterboards.ca.gov/) based on a search conducted on July 9, 2024. Note that only the open sites are listed in the table above and shown on Figure 12-2.

Abbreviations Used for Case Type: S = Contaminated soil, groundwater not impacted; G = Aquifer used for drinking water supply impacted; O = Other groundwater (uses other than drinking water); U = Under investigation.

Abbreviations Used for Status: 1 = Case Opened; 2 = Site Assessment; 3 = Remediation; 4 = Assessment and Interim Remedial Action; 5 = Verification Monitoring; 6 = Open Inactive; 7 = Eligible for closure; 8 = Open, transferred to another agency; 9 = Informational item / review complete.

Abbreviations Used for Contaminant: D = Diesel; G = Gasoline; S = Other Solvent or Non-Petroleum Hydrocarbon; O = Waste Oil / Motor / Hydraulic / Lubricating; P = Petroleum / Fuels / Oils, Volatile Organic Compounds (VOCs; including TCE = Trichloroethylene, PCE = Perchloroethylene); FO = Fuels Oxygenate; U = Unspecified.

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In response to State requirements that were for the most part implemented between the late 1980s and the early 2000s, underground storage tanks in California are now required to be double-walled, made of fiberglass, and fitted with flexible connections and leak detection systems. Given these changes, although there are at least 93 permitted underground storage tanks (USTs) in the city located at approximately 43 separate addresses20F
21, the chances of future leaks, albeit possible, are
low. The leak detection systems and monitoring programs now in place are meant to identify and track if and how much product has leaked, and how far a plume has spread, if applicable.

Furthermore, all significant spills, releases, or threatened releases of hazardous materials, including leaks from underground storage tanks or spills at the pump, must be immediately reported. To report all significant releases or threatened releases of hazardous materials, first call 911 (or the local emergency response agency), and then call the Governor's Office of Emergency Services Warning Center at 1-800-852-7550. In addition, all releases that result in injuries, or workers harmfully exposed, must be immediately reported to Cal/OSHA (CA Labor Code §6409.1 (b)). For additional reporting requirements, also refer to the Safe Drinking Water and Toxic Enforcement Act of 1986, better known as Proposition 65, and §9030 of the California Labor Code.

Some buildings in Santa Monica not included in Table 12-2 have Tanks in Underground Areas (TIUGAs) used to store lubricants, coolants, petroleum products, or other chemicals. These TIUGAs are also administered by the CUPA, with those storing petroleum products required to meet the guidelines of the Aboveground Petroleum Storage Act (APSA). The Hotel Casa Del Mar at 1910 Ocean Way, for example, has several TIUGAs throughout the structure used to store cleaning chemicals for its cooling tower, oil for the elevator equipment system overflow, carbon dioxide, diesel for its backup generator, laundry detergent, paint and latex for maintenance and repairs, and kitchen grease.

Transporters of Hazardous Materials
As mentioned previously, in accordance with Federal and State regulations, all transporters of hazardous materials are required to have onboard Safety Data Sheets specific to the substances that they are carrying. These are documents designed to help emergency response personnel assess the situation immediately upon arrival at the scene of an accident, and take the appropriate precautionary and mitigation measures. For hazardous materials releases in Santa Monica roadways, the primary agency in charge is the California Highway Patrol, with Caltrans, and the local fire department and sheriff providing additional resources as needed.

The western end of Interstate 10 traverses the city of Santa Monica in an easterly to northeasterly direction, whereas Highway 1 (Pacific Coast Highway) extends along the coast in a northerly to northwesterly direction. According to the National Hazardous Materials Route Registry maintained by the Federal Motor Carrier Safety Administration, a division of the U.S. Department of Transportation, the sections of Interstate 10 and Highway 1 that transect the city of Santa Monica are not prescribed or permitted to carry hazardous materials. Therefore, for pickup and delivery of hazardous materials in the city, the route selected must be the shortest-distance route from the pickup location to the nearest designated route entry location, and the shortest-distance route to the delivery location from the nearest designated route exit location, respectively. Freeways in the

21 Most gas stations typically have three to four USTs, with each tank storing a different grade of fuel (premium, midgrade, and regular)-and diesel. Each fuel type is stored in a different tank, with each tank connected to each dispenser via separate, individual pipes.

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vicinity of Santa Monica that are designated by the U.S. Department of Transportation as permitted to transport hazardous materials are listed in Table 12-3. These interstates in the vicinity of Santa Monica pose a potential for spills or leaks from non-stationary sources.

Table 12-3: Routes in the Vicinity of Santa Monica
Used to Transport Hazardous Materials and Explosives
Route Comments Designation Date
(Designation Code)
Interstate 405 from Interstate
5 [North Valley] to Interstate
5 [Irvine]
Designated non-radioactive hazardous materials
(NRHM) route
Recommended for Class 1 – Explosives
Poisonous Inhalation Hazard
10/28/1992 (B)
04/16/1992 (I)
Interstate 10 from Interstate
405
[Los Angeles] to Arizona
Designated non-radioactive hazardous materials
(NRHM) route
Recommended for Class 1 – Explosives.
10/28/1992 (B)
Interstate 105 from Interstate
405 [Hawthorne] to Interstate
605 [Norwalk]
Designated non-radioactive hazardous materials
(NRHM) route
Recommended for Class 1 – Explosives.
10/28/1992 (B)
Interstate 110 from Interstate
10 [Pico Union] to State 47
[San Pedro]
Designated non-radioactive hazardous materials
(NRHM) route
Recommended for Class 1 – Explosives.
10/28/1992 (B)
Source: https://www.fmcsa.dot.gov/regulations/hazardous-materials/national-hazardous-materials-routeregistry-state Route Designation Code: B = Class 1—Explosives; I = Poisonous Inhalation Hazard (PIH) As discussed in the introduction, train accidents or derailments can result, and have historically resulted in the release of hazardous substances. However, there are no railroad tracks extending across the Santa Monica area, so this hazard is not applicable to the study area.

Pipelines Through the City
One crude oil pipeline extends in a northwesterly direction across the city of Santa Monica, running beneath 23rd street then north to Cloverfield Boulevard, east along Colorado Boulevard, and to 26th Street.21F
22 This pipeline is owned and operated by Crimson Midstream, LLC., and it crosses over sections of the Santa Monica fault zone in the northeast portion of the city (Figure 12-2). If the Santa Monica fault ruptures the ground surface during an earthquake, the pipeline can be expected to rupture where it crosses or overlies the fault. Crude oil would consequently be released.

Vulnerability and Risk
Given there are 36 Significant Hazardous Materials Sites and 43 permitted underground storage tank sites in the city of Santa Monica, hazardous materials could accidentally be released, with the potential to negatively impact the environment. Facilities that use, store, generate or transport hazardous materials may change ownership or go out of business; as a result, the lists of users, generators, and transporters should be updated at least once a year. Residents, and property or business owners that are interested in obtaining current data for a particular area or site should

22 https://pvnpms.phmsa.dot.gov/PublicViewer/
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request it from the Santa Monica Fire Department or by visiting the appropriate websites referenced herein.

The city of Santa Monica is underlain by the Santa Monica fault (see Section 6). The city is also located near many onshore and offshore faults that have the potential to generate strong ground shaking in the region should they rupture in an earthquake. Therefore, all hazardous materials sites in Santa Monica could be subjected to moderate to severe seismic shaking. Their business plans should address, provide, and implement mitigation measures designed to reduce the potential for releases of hazardous materials during an earthquake. It has been shown in previous urban earthquakes that hazardous materials spills can occur even when the building does not suffer significant damage. Hazardous material containers not properly secured and fastened could easily be punctured and/or tipped over, pipes may rupture, and storage tanks may fail. Containers may also explode if subject to high temperatures, such as those generated by a fire. Lithium batteries may explode if shaken too vigorously or if they fall off as a result of ground shaking. Improperly segregated chemicals could react forming a toxic gas cloud. In a worst-case scenario, several hazardous materials releases could occur simultaneously.

One large-quantity RCRA site, one Cleanup Program site, and one permitted UST site are located in close vicinity of one of the several mapped traces of Santa Monica fault (see Figure 12-2). Surface fault ruptures near these facilities could result in structural damage and release of the chemical substances stored therein. Thus, avoidance of fault zones by facilities using, storing, or transporting hazardous materials should be considered in the future. Additionally, a crude oil pipeline crosses the Santa Monica fault zone at multiple locations in the northeast portion of the city (Figure 12-2).

The crude oil pipeline should be fitted with shutoff valves located outside of the Santa Monica fault zone to limit the amount of oil spilled should the pipeline rupture in an earthquake. Gas lines extending across the fault zone are also likely to be damaged if the Santa Monica fault ruptures the ground surface. Shaking of the ground alone as a result of an earthquake is likely to result in gas leaks around the City. For an analysis of gas leaks resulting from four different earthquake scenarios, refer to Section 6.

There is one (1) permitted underground storage tank (UST) site in Santa Monica near the 100-year flood zone along the coastline. This is an UST at the Hotel Casa Del Mar. Moreover, several buildings near the coastline have regulated above-ground storage tanks that contain fuel for backup power generators. Street flooding as a result of intense storms or inadequate storm drain capacity could result in the flooding of some of these hazardous materials facilities.

The facilities discussed above and listed in Table 12-1 are for the most part handling chemical substances that occur in a liquid or solid state at normal temperatures and pressures. A leak of any of these substances (such as gasoline, diesel and motor oil used at gas stations and vehicle repair centers, and solvents used in dry cleaners) could impact the underlying soils. While such a release and subsequent contamination would be unfortunate and would require extensive resources to cleanup, it would not pose an immediate danger to the surrounding population. Past studies of hazardous materials release scenarios as a result of an earthquake have concentrated on the two substances that are thought to pose the biggest threat to a community during an earthquake: Chlorine and anhydrous ammonia. These substances, under normal temperature and pressures, occur in a gas state, and thus if released to the atmosphere, form clouds that can spread to adjacent areas, posing a threat to the surrounding community.

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Chlorine is one of the products most often used as a disinfectant by swimming pool, drinking water and wastewater facilities, making chlorine one of the most prevalent extremely hazardous substances. Chlorine is typically found in the form of a colorless to amber-colored liquid, or as a greenish-yellow gas with a characteristic odor. The liquid solutions are generally very unstable, reacting with acids to release chlorine gas (such as bleach mixed with vinegar or toilet bowl cleaner containing hydrochloric acid). Mixing bleach with other products is the largest single source of inhalation exposure reported to poison control centers. Chlorine gas is heavier than air and therefore stays close to the ground, where it can impact individuals. Exposure to chlorine gas generally impacts the respiratory system, with coughing, shortness of breath, chest pain, and burning sensation in the throat reported as the most common symptoms. Respiratory distress can occur at even low concentrations of less than 20 parts per million (ppm). At high concentrations (> 800 ppm) chlorine gas is lethal.

Ammonia is a compound of hydrogen and nitrogen that is used extensively, either directly or indirectly, in several different types of applications, including the manufacture of pharmaceuticals, fertilizers, and commercial cleaning products. The colorless gas has a strong pungent odor, and unlike chlorine gas, is lighter than air. Exposure to high concentrations of ammonia can lead to lung damage and death. Solutions of ammonia can be irritating to the eyes and mucous membranes, and to a lesser extent, the skin. A mixture of an ammonia solution with a chlorine-containing compound, such as bleach, can result in the formation of a highly poisonous gas.

Chlorine pellets, chlorine solutions and ammonia solutions can be found at supermarkets, hardware stores and other locations that sell pool supplies and cleaning products. Bleach and ammonia solutions can be found in almost every household and in commercial and industrial facilities, including hotels, hospitals, medical and veterinary facilities, etc. Proper storage and usage practices are required at all of these locations to reduce or eliminate the potential for a toxic release of chlorine, ammonia, or worse, a mixture of the two. Chlorine and/or ammonia may be used at the wastewater treatment plants owned by the City of Santa Monica. Chlorine is also likely to be used by water storage facilities to treat the municipal supply of drinking water. Proper operations and maintenance procedures are required at these facilities to prevent equipment and process failures that could lead to the unauthorized release of these substances at concentrations that could impact the surrounding areas. These facilities are required to maintain a comprehensive program of personnel training, security enforcement and equipment monitoring to reduce the risk of an accidental or intentional (terrorist) release.

In the Santa Monica area, spills or leaks from a non-stationary source could occur in the event of an accident involving a vehicle carrying hazardous substances. Although the sections of both Interstate 10 and Highway 1 that extend across the city are not permitted to transport hazardous materials, hazardous materials still need to be transported into and out of the city to accommodate the users of these materials within city limits (such as the gas stations, hospitals, water treatment facilities, pharmacies, etc.). Other routes in the region are permitted to transport hazardous materials, including Interstates 405, 110, 105, and 10 (east of I-405). Therefore, for pickup and delivery of hazardous materials in the city of Santa Monica, the route selected must be the shortest-distance route from the pickup location to the nearest designated route entry location, and the shortestdistance route to the delivery location from the nearest designated route exit location, respectively.

The City of Santa Monica is currently both the largest producer of groundwater and the sole producer of drinking water within the Santa Monica Subbasin. Historically, Santa Monica’s groundwater Local Hazard Mitigation Plan Section 12
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supply has been negatively impacted by the gasoline additives of Methyl tert-Butyl Ether (MTBE) and tert-Butyl Alcohol (TBA), which were detected in several of the Charnock and Olympic groundwater wells during the late 1990s to early 2000s. These fuel additives found their way into the groundwater via Leaking Underground Storage Tanks (LUSTs) from various gasoline stations within the Charnock Subbasin (City of Santa Monica Annual Water Quality Report, 2023). After the contaminants were first detected in 1996, production from the local groundwater wells immediately ceased and the City of Santa Monica was forced to import most of its drinking water to meet water resource demands.

The City now uses virgin Granular Activated Carbon (GAC) filtration to treat the groundwater from these wells and reduce MTBE and TBA concentrations to levels well below the Maximum Contaminant Level of 5 parts per billion (ppb).

More recently, in 2019, City staff proactively sampling the City’s drinking water sources for PFAS detected perfluorooctanoic acid (PFOA) in the Olympic Well Oil Field (Draft 2023 Annual Water Shortage Assessment Report). These substances are readily absorbed but not readily eliminated from the human body, and according to the State Water Resources Control Board (SWRCB), long-term exposure can cause harmful health effects to a developing fetus or infant, suppress the immune system, disrupt thyroid function, increase liver weight, and lead to cancer. The City will use ultraviolet-advanced oxidation processes and a two-stage GAC filtration at the Arcadia Treatment Plant to treat this water, and will perform continuous monitoring for these substances.

HAZARDOUS MATERIALS MITIGATION ACTIVITIES
In accordance with State and Federal laws, all businesses that handle hazardous materials in the city of Santa Monica should continue to prepare and file business plans with the City’s CUPA. The business plans for all hazardous materials businesses in or near the coastal flooding zone should address the hazards of flooding, and all handlers of hazardous materials near the Santa Monica fault zone should provide for mitigation measures to be implemented to reduce the potential for hazardous materials to leak or spill during a natural disaster. All Santa Monica Fire Department (SMFD) engine companies are trained to respond to hazardous materials incidents, but Fire Station 5, located near the Santa Monica airport, is specifically equipped to respond to hazardous materials spills and emergencies. The locations of the SMFD stations are shown on Figure 12-2, with Station 5 highlighted.

Given that several of the existing hazardous materials sites in Santa Monica are located near schools and other critical facilities, that transportation incidents could also occur along any of the truck routes in the city, and that gas or sewage leaks can occur anywhere in the city, it is advisable to encourage schools and other critical facilities with populations with limited mobility to develop plans that include a protocol to be followed in the event of a leak of hazardous materials that would require them to evacuate or shelter-in-place for a long duration. If possible, future significant hazardous materials sites should be sited in areas far away from facilities with evacuation concerns.

Pipeline operators are responsible for the continuous maintenance and monitoring of their pipelines, including the repair, when necessary, of corroded sections of pipe. All excavations or drilling operations near pipelines (including sewer, water, gas, and crude oil) and other utilities (cable, electric and communication lines, etc.) should be conducted only after proper clearance by the appropriate utility agencies or companies. California law requires that all excavation locations be first cleared – this is done by the Underground Service Alert of California or DigAlert (http://www.digalert.com or www.call811.com). Their telephone number is 8-1-1. Calls need to be Local Hazard Mitigation Plan Section 12
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made at least two (2) working days before digging, and the proposed excavation area needs to be delineated or marked.

Ideally, with the development of new, “greener” products and the increasing recognition that sensitive individuals can react to chemicals used in many products, households have and will continue to opt for non-hazardous products for day-to-day cleaning. However, many households have over the years stored a variety of materials that cannot and should not be disposed of in the regular trash. These products and materials include motor oils and filters, fuels, fertilizers, paints, solvents, fluorescent tubes, batteries, electronic waste (e-waste), paints, art supplies, pool and photo chemicals, household cleaning chemicals, and sharps. Good, usable leftovers of these products can be donated to willing recipients, such as family members, neighbors and community organizations like churches. But others will want to deliver these substances to an appropriate collection center.

The City of Santa Monica has adopted a Residential Household Hazardous Waste Door to Door Collections Program in accordance with the California Integrated Solid Waste Management Act of 1989. This program is contracted with CleanEarth, Inc., and only open to residents of Santa Monica.

Residents can schedule a pickup via the link above. After a pickup request form is submitted, CleanEarth, Inc. personnel will visit your home and safely and compliantly remove residential household hazardous waste that should not be placed in your typical trash or recycling bin. A few items are not accepted through this program. These include explosives or explosive waste, ammunition, biological or biohazard waste, medical waste, and radioactive waste. Additionally, the maximum disposal limit for the Residential Household Hazardous Waste Door to Door Collections Program is 125 pounds per pickup. Several businesses in and near the city of Santa Monica, such as The Home Depot, UPS Mailing Centers, Office Depot and similar stores, may also receive and recycle certain kinds of materials such as used batteries, spent light bulbs, and old electronics.

Residents are encouraged to call these businesses directly to obtain additional information regarding their hours of operation, and the types of waste that they receive. Finally, unwanted or expired prescription drugs can now be safely disposed of 24 hours a day, seven days a week, at select prescription drug drop-boxes.

The City also operates the Conditionally Exempt Small Quantity Generator (CESQG) Program to provide small quantity generators (i.e. businesses) operating within Santa Monica with a legal and affordable solution to hazardous and/or universal waste disposal. Small businesses that meet these qualifications can drop off their hazardous waste materials on the second Wednesday of each month between the hours of 8:00 AM and 2:00 PM at the City Yard Facility located at 2500 Michigan Ave, Santa Monica, CA 90404. These programs are designed to reduce the amount of waste taken to the landfill. However, if needed, the closest active landfill facility is Burbank Landfill Site No. 3, located at 1600 Lockheed View Drive, in Burbank, CA 91504. This landfill accepts only non-hazardous solid waste, and they can be reached at (818) 238-3915.

A more convenient way to dispose of non-hazardous waste is to use a transfer station. These are facilities that serve as local collection points prior to the final disposal site. Southern California Disposal and Recycling Company, Inc. is a transfer station located in the city of Santa Monica (1908 Frank Street) that can be utilized by local residents and businesses for a fee. For additional contact information refer to the Local Resources at the bottom of this section.

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HAZARDOUS MATERIALS MANAGEMENT RESOURCE DIRECTORY
City Resources
City of Santa Monica Certified Unified Program Agency (CUPA) Division of the City’s Fire Department
(310) 458-4971
Email: [email protected]
City of Santa Monica Water Resources Division
1685 Main Street
Santa Monica, CA 90406-2200
(310) 424-2672
https://www.santamonica.gov/topic-explainers/your-guide-to-water City of Santa Monica Office of Sustainability and the Environment (310) 458-2213
https://www.santamonica.gov/departments/public-works/office-of-sustainability-and-theenvironment Santa Monica Basin Groundwater Sustainability Agency (SMBGSA (310) 351-9465
https://www.santamonica.gov/gsp
Local Resources
Underground Service Alert of Southern California (DigAlert) Telephone: 811
https://www.digalert.com
www.call811.com
South Coast Air Quality Management District (South Coast AQMD) 21865 Copley Drive, Diamond Bar, CA 91765
(909) 396-2000
http://www.aqmd.gov/
Metropolitan Water District (MWD) of Southern California 700 North Alameda Street, Los Angeles, CA 90012-2944
P.O. Box 54153, Los Angeles, CA 90054-0153
(213) 217-6000
https://www.mwdh2o.com
CleanEarth, Inc. (Santa Monica Residential Household Hazardous Waste Program) (877) 445-2371
https://www.cleanearthinc.com/santa-monica-ca-residential-household-hazardous-waste-program Local Hazard Mitigation Plan Section 12
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Southern California Disposal and Recycling Company, Inc. 1908 Frank Street, Santa Monica, CA 90404
(310) 828-6444
https://www.scdisposal.com/htmls/transfer.html
County Resources
Los Angeles County Certified Unified Program Agency (CUPA) 200 North Main Street, Suite 1780, Los Angeles, CA 90012 (213) 978-3680
https://lafd.org/fire-prevention/cupa
County of Los Angeles Public Health (Current Landfill Facilities in Los Angeles County) 5050 Commerce Drive, Baldwin Park, CA 91706
(888) 700-9995
http://www.publichealth.lacounty.gov/eh/business/landfill-facilities.htm State Resources
California Governor’s Office of Emergency Services – Spill Release Reporting Any significant release or threatened release of a hazardous material needs to be reported immediately to the CalOES State Warning Center.
(800) 852-7550 or 911
https://www.caloes.ca.gov/office-of-the-director/operations/response-operations/firerescue/hazardous-materials/spill-release-reporting/ California Regional Water Quality Control Board – Los Angeles Region 320 West 4th Street, Suite 400, Los Angeles, CA 90013
(213) 576-6600
https://www.waterboards.ca.gov/losangeles/
https://geotracker.waterboards.ca.gov
California Water Resources Control Board - Division of Drinking Water:
(818) 551-2004
https://www.waterboards.ca.gov/drinking_water/programs/ California Department of Toxic Substances Control (DTSC) 1001 “I” Street (PO Box 806)
Sacramento, CA 95812
(916) 551-1313
https://www.dtsc.ca.gov
California Department of Transportation (Cal Trans) – District 7 100 South Main Street, Los Angeles, CA 90012
(213) 897-1200
https://cleancalifornia.dot.ca.gov/
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California Department of Conservation, Geologic Energy Management Division (CalGEM) (916) 445-9686
https://www.conservation.ca.gov/calgem
Federal Resources
Environmental Protection Agency (EPA) – Region 9
75 Hawthorne Street, San Francisco, CA 947-8000
(415) 947-8000; (866) EPA-WEST
https://www.epa.gov
https://www.epa.gov/aboutepa/forms/contact-epa
Federal Emergency Management Agency (FEMA) – Region IX
1111 Broadway, Suite 1200, Oakland, CA 94607-4052
510-627-7100
https://www.fema.gov
U.S. Department of Transportation, Federal Motor Carrier Safety Administration 1200 New Jersey Avenue, SE, Washington, DC 20590
(800) 832-5660
https://www.fmcsa.dot.gov/
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SECTION 13: AIRPORT HAZARDS

WHAT AIRPORT ACTIVITIES COULD POSE A HAZARD TO THE CITY OF SANTA MONICA?
The term “airport hazard” typically refers to a structure, object (such as a tree or hill), or land use which obstructs the air space required for aircraft to land or take off at an airport or is otherwise hazardous to such landing or taking off activities. In this document, the term “airport hazards” also refers to activities associated with the operation of an airport that could pose a negative impact on the health and safety of persons in the immediate vicinity, or could impact properties, facilities, infrastructure and/or the environment. Specifically, commercial, industrial, residential, and recreational properties near Santa Monica Airport (SMO), and the people occupying such structures, could be exposed to aviation-related accidents and other airport-related hazards. Airport safety thus must address not only on-airport issues but potential safety hazards that can affect off-airport uses and populations. Subjects discussed in this section include ground and airspace safety related to airport operations, aviation noise, and the potential presence of hazardous materials related to past and present operations at SMO.

To address these subjects, this document first provides an historical overview of SMO, and describes its physical setting, followed by a summary of past aviation accidents in southern California and in and near Santa Monica. The report then describes the conditions and legal obligations of the airport and the aviation community, including requirements imposed by the Federal Aviation Administration (FAA) and local emergency response services. Finally, the report evaluates the impact of potential events that might take place within Santa Monica city limits. The analysis relies on a review of past accidents to discuss the likelihood of an aviation accident occurring in the future, the areas or functions that can be expected to be most seriously impacted if an aviation or airport-related accident occurs, and the actions that will most effectively protect life and safety, property, the environment, and the interests of the City if such event occurs.

BACKGROUND
Airport Setting
SMO is located along the southeastern edge of Santa Monica (Figure 13-1), with the easternmost portion located within City of Los Angeles limits. The airport has a single runway, oriented westsouthwest, with most takeoffs occurring westward toward the Pacific Ocean during prevailing wind patterns. Prior to 2017, SMO provided a lighted runway approximately 5,000 feet long and 150 feet wide, but in 2017, the runway was shortened to 3,500 feet.

Development of the SMO airfield altered the local topography to optimize the slope of the runway.

To do this, the northwest portion of the property was cut into relative to the adjoining slope, and the southwest portion of the property was raised. As a result, the SMO site slopes gently from east to west, with a high point of approximately 180 feet (55 meters) above sea level (asl) at the northeast corner of the site and a low point of approximately 99 feet (30 meters) asl at the southwest corner of the airport property (Figure 13-1). The airport site is somewhat elevated above terrain to the south, is steeper at the southwest corner and is lower than adjoining land north of Marine Street. The resulting changes in terrain between the airport and adjoining residences serve to somewhat isolate the airport property.

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Figure 13-1: Regional Setting of the Santa Monica Airport Local Hazards Mitigation Plan Section 13
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Runoff associated with precipitation and irrigation on airport property flows to the southwest and is captured in intercept channels and discharged into its heavily vegetated margins on the west. There are also catch basins located throughout the airport property. Some of these flow to a 36-inchdiameter stormwater main along Airport Avenue, which then flows west through a series of stormwater mains and ultimately drains to the Penmar Recreation Center Park.

The SMO site is comprised of a large flat area with a relatively high percentage of paved surfaces.

This in effect makes the SMO site a “discontinuity” within the surrounding urban landscape. The environmental setting at the Santa Monica airport property is expected to change and evolve over the next few years, as SMO is scheduled to close at midnight on December 31, 2028. The City is currently undergoing a public planning process to determine the future of the Santa Monica Airport land in advance of closure. Currently, however, the airport continues to operate with a mix of aviation and non-aviation uses, as described further below, with this report addressing potential hazards related to the past and current operations at SMO.

Santa Monica Airport History
Santa Monica has been served by a local municipal airport since at least 1922, when a tract of farmland at the eastern boundary with the city of Los Angeles was first used as a provisional airfield.0F 1 In 1924, Santa Monica voters approved a park bond ballot measure to purchase the farmland, and the City purchased 158 acres adjacent to Ocean Park Boulevard for use as the Santa Monica Airport (SMO) and for recreation that included an archery range, golf course, tennis courts, and other recreation opportunities. Previously known as Clover Field, the general aviation1F 2 airport played an
integral role in the development of Santa Monica from a small beach town of only a few thousand residents to the sophisticated residential community, urban destination and regional job center that the city is today. SMO is the oldest operating airfield in Los Angeles County, and one of the oldest airports in the United States (U.S.). In the late 1960s, SMO was arguably one of the busiest, if not the busiest general aviation airport in the world, with more than 356,000 airport operations (takeoffs and landings) in a year.2F
3 These statistics have changed since, the airport in Van Nuys, California (KVNY) as of 2020, ranked the busiest general aviation airport in the U.S., and one of the busiest in the world.3F
4 The City has continuously owned and operated SMO since its inception, except during World War II (WWII), when it was leased to and operated by the Federal government, with the airport housing the Army’s 40th Division Aviation and 115th Observation Squadron. Before, during, and for a brief period after the war, SMO was also home to the Douglas Aircraft Company (Douglas); the Santa Monica-based company designed and built aircraft for the U.S. military forces, and starting in the 1930s, commercial transport aircraft. After WWII, Douglas reduced its workforce and later left the airport for a larger facility in Long Beach.

1 According to https://www.smgov.net/Departments/Airport/History.aspx, pilots flying World War I planes were using the site as an informal landing strip since around 1917. 2 A general aviation airport is a public-use airport that supports a variety of services, including air cargo, emergency medical transportation, law enforcement, firefighting operations, and non-commercial aviation activities like flight instruction, personal recreational flying, business travel, etc. General aviation airports have no scheduled commercial services, or less than 2,500-passenger boardings annually. General aviation airports are the most common type of airport in California. 3
https://www.smgov.net/Departments/Airport/History.aspx, accessed May 19, 2025. 4 https://generalaviationnews.com/2020/02/03/top-10-busiest-general-aviation-airports/ and https://en.wikipedia.org/wiki/Van_Nuys_Airport, accessed June 12, 2025.

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Historical uses at SMO4F
5 include a golf course on the south airport area, unpaved dirt roads for access to nearby aircraft support facilities, aircraft parking, aircraft tie-downs, and developed structures and storage units, including storage for the Barker Hangar that was constructed in 1954 (Parsons, 2016).

By the late 1950s, the structures on the west paved surface area and the adjacent Barker Hangar were present mostly as they are today. The existing aircraft-related commercial uses at 3025 Airport Avenue (now occupied by Proteus Air Service) were in place since at least 1967. Also since the 1960s, the east paved surface area was used for aircraft tie-down purposes; this land use continued until 2016, when the airplane tie-downs were removed and land in the vicinity was developed. The Airport Administration Building in the northern portion of the airport was replaced or improved in the 1980s (Parsons, 2016).

Today, SMO property is currently approximately 192 acres (17 acres of which are in the City of Los Angeles but all 192 acres are owned by the City of Santa Monica), with this acreage used for both aviation and non-aviation activities, including offices and educational facilities (see below). The following briefly describes the City’s General Plan land use designations at and surrounding the airport (Figure 13-2), and the current mix of land uses in this area. This in turn provides context as to potential airport safety hazards.

The lands encompassed in the SMO boundary are designated “Institutional/Public Lands” in the Santa Monica General Plan’s Land Use and Circulation Element (LUCE), which allows for the airport and associated uses. Lands to the immediate north of the airport in Santa Monica are designated “Single Family Housing,” “Office Campus,” and “Parks and Open Space.” Immediately north of the airport is the City’s Clover Park, the fully developed Airport Business Park and the Santa Monica Business Park office and commercial development, all of which extend north to Ocean Park Boulevard (Figure 13-2). Lands immediately north of the west end of the airport include fully developed single-family neighborhoods and a City of Santa Monica Fire Station (Fire Station No. 5).

To the west and southwest, land uses include extensive single-family development, the Penmar Golf Course and the Penmar Park and Recreation Center.

Land use to the east and south is designated primarily as “Low Residential” on the City of Los Angeles General Plan land use map for the Palms – Mar Vista – Del Rey areas, with small pockets assigned to “Limited Manufacturing,” “Low Medium Residential,” “Medium Residential,” and “General Commercial.”5F
6 Specifically, east of the airport and Bundy Drive are single-family homes of the Mar Vista residential neighborhood and limited commercial development on National Boulevard. Lands to the south of the airport property are predominantly single-family homes, the Bundy Campus of Santa Monica College and the North Venice Little League Fields and Ocean View Community Gardens to the southeast (Figure 13-2). The nearest schools to SMO are the adjoining SMC Bundy Campus, Mar Vista Elementary (±0.6 mile southeast), and Walgrove Avenue Elementary (±0.6 mile southwest).
5 Most of the information in this section is derived from the Airport Park Expansion Project Final EIR prepared by Amec Foster Wheeler (2018). The EIR references a Phase I Environmental Site Assessment (ESA) prepared by Parsons in February 2016; a Phase II ESA prepared by ES Engineering Services, LLC in September 2016; a Supplemental Site Assessment Report for the West Parcel, a Supplemental Site Assessment Report for the East Parcel, both prepared by ES Engineering in July 2017; and a Screening Level Risk Assessment for the East Parcel prepared by Parsons in August 2017 (all hazardous materials investigations are included as Appendix D of the Final EIR by Amec Foster Wheeler, 2018). 6 City of Los Angeles General Plan Online Land Use Mapping; https://planning.lacity.org/odocument/7faa8bdde766-42fc-b997-1b1bd5576870, accessed on January 17, 2023 and January 16, 2025.

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Figure 13-2: Land Use Around Santa Monica Airport
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The SMO property is currently home to about 166 businesses from over forty industry sectors, including aviation businesses, the Museum of Flying, the Barker Hangar event venue, art studios, SNAP, a portion of the Santa Monica College (SMC) Bundy Campus, miscellaneous offices, surface parking lots, restaurants, and other non-airport related uses. Other airport uses include the two-story General Aviation Facility Specialty Hangar (3100 Donald Douglas Loop South), the two-story Airport Administration Building (3223 Donald Douglas Loop South), and the City’s Transient Aircraft Parking Area. The Administration Building can also function as an alternate Emergency Operations Center if needed. As mentioned above, Santa Monica’s Fire Station No. 5 at 2450 Ashland Avenue is also located on SMO property.

Airport Operations
In 2023 (the most recent data available as of the writing of this document), SMO recorded 57,110 flight operations (i.e., departures and arrivals), with propeller (single-engine piston, multi-engine piston, and turboprop) aircraft accounting for more than 92% of these.6F 7 The rest of the operations
were made by jet engines and helicopters. Of these totals, 18% of the operations were aircraft on instrument flights (IFR itinerant), 46% were VFR itinerant, and 36% were local (VFR local operations)7F
8 . Flight operations data for SMO between the years 2018 and 2023 are summarized on Table 13-1 below. Note that the number of operations in 2023 were 21% less than in 2022. The 2023 numbers are the lowest since at least 2011, and even lower than the 2020 numbers (58,228 operations), during the COVID-19 pandemic, when SMO’s control tower adopted a reduced-hours operational schedule. This is illustrated graphically on Figure 13-3. For comparison purposes, the Los Angeles International Airport (LAX), located approximately 5.5 miles to the south of SMO, reported 575,097 operations in 2023, ranking as the fourth busiest airport in North America.8F 9 Annual
operations at LAX between 2013 and 2023 ranged between a high of 707,833 in 2018 and a low of 379,364 in 2020, during the COVID-19 pandemic.9F
10 7
Calendar Year 2023 Annual Operations Report, Santa Monica Municipal Airport, December 2024, available from https://www.santamonica.gov/media/Public%20Works/Airport/noise%20reports/Calendar%20Year%202023%20 Anuual%20Operations%20Report.pdf, accessed January 15, 2025. 8 Itinerant aircraft means aircraft using the airport on an irregular basis, or without regular scheduling at SMO; i.e., itinerant aircraft means aircraft not based at SMO, with the flights arriving from or departing to another airport outside of SMO’s Class D airspace. Local aircraft are based at SMO, and local operations include aircraft departing the airport area to a designated practice area, and aircraft returning from the designated practice area to the SMO airport. For SMO, “local traffic” is defined as aircraft that stayed within SMO’s Class D controlled airspace, either within 5 nautical miles of SMO or within SMO’s traffic pattern.

IFR = Instrument Flight Rules, VFR = Visual Flight Rules 9 As of 2022-2023, based on https://en.wikipedia.org/wiki/List_of_the_busiest_airports_in_North_America#2023, accessed June 12, 2025. 10 https://www.lawa.org/-/media/lawa-web/lawa-our-lax/studies-and-reports/aviation-activity-analysis/2023-aviationactivity-analysis_final.ashx, accessed January 15, 2025.

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Table 13-1: Annual Flight Operations at SMO, 2018-202310F 11 Year 2018 2019 2020 2021 2022 2023
Total Operations 72,061 77,038 58,228 67,986 72,039 57,110 Itinerant 16% 14% 12% 14% 14% 18%
VFR Itinerant 53% 49% 46% 45% 46% 46%
Local 31% 37% 42% 41% 40% 36%
By Aircraft Type
Propeller 59,557 65,732 51,632 60,334 63,035 52,814
Single- and multiengine 53,682 60,784 48,915 57,158 59,012 48,589 Turboprop 5,875 4,948 2,717 3,176 4,023 4,225
Jet 2,971 3,064 2,030 2,725 3,041 2,586
Helicopter 3,658 3,294 1,849 1,751 1,940 1,710
Currently, aircraft typically approach the airport from the east and depart toward the west.

Helicopters depart to the north from a helipad at the center of the airport. The SMO air traffic control tower is manned from 7:00 A.M. to 9:00 P.M. Although arrivals are permitted 24 hours a day, pilots are requested to avoid all operations between 11:00 P.M. and 7:00 A.M. Monday through Friday, or until 8 A.M. on weekends. Exceptions are allowed for medical or public safety flights.

SMO operations involve the routine use, storage, and transport of hazardous materials, including 100 Low Lead and Unleaded aviation gasoline (AvGAS) and jet fuel, cleaning solvents, lubricants and degreasers, and other routine materials such as commercially available cleaning products and 11 Data for Table 13-1 and Figure 13-3 extracted from
https://www.santamonica.gov/media/Public%20Works/Airport/noise%20reports/2010_Annual_Noise_Report.pdf and
https://www.santamonica.gov/media/Public%20Works/Airport/noise%20reports/Calendar%20Year%202023%20 Anuual%20Operations%20Report.pdf, both accessed January 15, 2025. -
20,000
40,000
60,000
80,000
100,000
120,000
140,000
160,000
Figure 13-3: Annual Operations by Year at SMO, 2001-2023 Local Hazard Mitigation Plan Section 13
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herbicides. Thus, beyond the most dramatic of airport operational hazards—aircraft accidents— there are a variety of other potentially significant hazards that can adversely affect surrounding lands and land use. These include a typically noisy environment with occasionally high intensity noise levels, engine blasts that may result in vibrations, odors, light pollution, disruption of roadway circulation networks and others. Similarly, “development around an airport, particularly in the approach and departure paths, can create obstructions in the airspace traversed by an approaching or departing aircraft. Additionally, certain land uses have the potential to attract wildlife or to create hazards to aircraft such as a distracting glint or glare, smoke, steam, or invisible heat plumes.11F 12”
Several of these considerations of land use compatibility are discussed further in this document.

HISTORICALLY AND LOCALLY SIGNIFICANT SOUTHERN CALIFORNIA

AVIATION ACCIDENTS
SMO and LAX generate a large fraction of the aviation traffic above the city of Santa Monica, although significant traffic over the city is also the result of aircraft transitioning north and south over LAX via a number of VFR corridors. Moreover, and especially during the summer, there is also noticeable transient traffic from helicopter and aircraft operations. As the data in the following tables show, however, a large percentage of aviation accidents and incidents12F 13 that have been reported in
Santa Monica, or in Santa Monica Bay, are associated with aircraft that were taking off or landing at either LAX or SMO. As described in the previous section, hundreds of thousands of aircraft operations are conducted annually from these two airports combined, with LAX being responsible for about 90% of the total. It is important to keep these numbers in mind when describing the air traffic accidents and incidents that have historically occurred in the area. Essentially, as the descriptions and tables in this section show, the number of aircraft incidents and accidents in the southern California region, and especially related to air traffic associated with LAX and SMO amount to a very small percentage of the total number of airport operations, on the order of less than one incident out of more than one million (it is impossible to calculate an exact figure because the number of operations vary from year to year and there are several years where no accidents or incidents occurred).

An inherent difficulty in managing safe airport operations is the unpredictability or uncertainty of future events that may occur with occasional aircraft operations. Since aircraft accidents happen infrequently and the time, place, and consequences of their occurrence cannot be predicted, conceptualizing operational risks is a difficult, but essential, planning activity. As cited above, accidents at or associated with flight operations originating at SMO is one factor for analyzing future aviation risk. Therefore, assessing the type, frequency and consequences of past accidents informs future planning at the airport while it continues to operate as such. This is discussed further below.

12 California Airport Land Use Planning Handbook, prepared by Caltrans Division of Aeronautics. October 2011, available from https://dot.ca.gov/-/media/dotmedia/programs/aeronautics/documents/californiaairportlanduseplanninghandbook-a11y.pdf. 13 An aviation accident is a serious event that results in death, serious injury, or significant damage to the aircraft.

An aviation incident is an event that affects or could affect safety but does not meet the criteria of an accident.

This means that the event did not involve serious injuries or fatalities, and the aircraft did not sustain major damage, remaining airworthy or not requiring major structural work. All accidents and certain incidents must be reported to the National Transportation Safety Board (NTSB).

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Table 13-2 summarizes significant commercial aviation accidents and incidents that have occurred in southern California since at least 1936. These include major aviation accidents that resulted in significant or complete destruction of the aircraft and loss of life anywhere within southern California airspace, and minor to moderate accidents and incidents that involved aircraft flying into or out of LAX or SMO. Accidents involving small aircraft that did not occur in Los Angeles airspace, such as the small aircraft crash in Fullerton on January 2, 2025, or the two aviation accidents that occurred in San Diego in May and June 2025, respectively, are not included here.

Note that most (but not all) of the incidents summarized here, especially those that have occurred in the past 25 years, while no doubt frightening to those involved, resulted in no injuries or casualties. Incidents that occurred on the ground are not included unless the situation could have been much worse, with the potential to impact tens to hundreds of people. It is noteworthy to point out that several of the earlier incidents prompted changes in operations and rules that have since helped to make air travel safer. Where appropriate, these changes are briefly discussed following the description of the accident or incident. Thus, today, there are a variety of systems and procedures in place aimed at mitigating aviation hazards, including air traffic control systems and operational safety requirements for pilots.

Table 13-2: Significant Historical Aviation Accidents and Incidents in Southern California13F 14 Date Description Casualties
December
27, 1936
Plane crashed near Newhall. Deemed pilot error for
attempting to fly through Newhall Pass at a lower elevation than surrounding mountains.

All 9 passengers and 3 crew members
died.

January 10,
1945
During missed approach of airport, plane crashed into the Verdugo Hills.

All 21 passengers and 3 crew
members died.

January 31,
1957
Douglas DC-7B flying out of SMO was involved in a mid-air collision with U.S. Air Force Northrup F-89 Scorpion. Aircraft crashed into school yard of Pacoima Jr. High School and the grounds of Pacoima Congregational Church. Deemed pilot
error, with both crews having failed to exercise “see and avoid” procedures. As a result, restrictions were imposed on all military and civilian aircraft, requiring all test flights be made over water or approved sparsely populated areas.

All 4 crew members of DC-7B died.

One crew member of the Scorpion
bailed and survived, although
injured. Pilot died.
2 students at Jr. High were killed at
the scene and 1 died at hospital two
days later. Approximately 75 students
were injured, some critically.

May 22,
1968
Passenger helicopter crashed in Paramount due to mechanical failure of blade rotor system. Wreckage fell on dairy farm.

All 20 passengers and 3 crew
members died.

August 14,
1968
Passenger helicopter crashed in a park in Compton, next to a residential area. Cause attributed to fatigue failure with the main rotor blade separating mid-flight. In response, the Federal Aviation Administration (FAA) required an immediate inspection of all Sikorsky S-61 helicopter spindle units, the adoption of more precise and frequent inspection of said units, and a study to establish the retirement life for that part.

All 18 passengers and 3 crew
members died.

January 13,
1969
Flight from Denmark to Los Angeles crashed into Santa
Monica Bay, approximately 6 nautical miles west of LAX; Out of the 45 total onboard, 15 died
and 17 were injured.

14 The accidents and incidents included here were compiled from a variety of sources, including the National Transportation Safety Board data set of aviation accidents from 1962 through the present available from https://www.ntsb.gov/safety/data/Pages/Data_Stats.aspx; cases in the Aviation Safety Network database for incidents near LAX, available from https://aviation-safety.net/database/airport/airport.php?id=LAX, and various Wikipedia entries in the category “Airliner accidents and incidents in California,” available from https://en.wikipedia.org/wiki/Category:Airliner_accidents_and_incidents_in_California; all entries accessed in January-July 2025.

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Date Description Casualties
deemed pilot error.

January 18,
1969
Flight from LAX to Milwaukee, Wisconsin crashed into Santa Monica Bay due to mechanical failure of engines and crew becoming disorientated when all lights onboard went dark due to power loss.

All 38 onboard died.

June 6, 1971 Flight to Salt Lake City, Utah had departed LAX while Phantom II F-4 of the U.S. Marine Corps (USMC) was approaching El Toro USMC air station near Irvine. Aircrafts collided in midair over San Gabriel Mountains near Duarte. Crash prompted US Air Forces to reduce number of military aircraft operating under visual flight rules and require military aircraft to contact civilian air traffic controllers.

All 49 onboard the passenger aircraft
died. F-4 pilot died; F-4 radar
intercept officer ejected and survived.

April 12,
1977
Flight from San Diego to Atlanta with stopover at LAX. Aircraft suffered mechanical malfunction that caused aircraft to pitch aggressively. Pitching force was counteracted by reducing thrust to wing engines and moving passengers forward in the cabin as much as possible. Pilots were able to land safely at LAX.

All 52 onboard survived with no
injuries.

September
25, 1978
Flight from Sacramento to San Diego collided mid-air with a private Cessna over North Park, a San Diego residential area.

Accident was deemed the result of a series of missteps, including that crew lost sight of the Cessna (did not “keep visual separation”), errors by air traffic control, Cessna pilots did not maintain their assigned heading and did not tell air traffic control of their change in course. As a result of this accident, the FAA implemented a Class B Airspace to provide for the separation of all aircraft operating in the area; all aircraft are now required to operate under “positive radar control.” As a result of this and other similar collisions, including the one on 1986 (below), all commercial passenger aircraft and almost all commercial cargo planes are now required to have a Traffic Collision Alert and Avoidance System (TCAS) that provides visual and audible alerts to pilots if another aircraft is approaching. Small single-engine planes like the Cessna are not required to have a TCAS.

All 135 onboard Flight 182 and 2
onboard the Cessna died. In addition,
7 people on the ground died, for a
total of 144 deaths. Deadliest aviation
disaster to date in California.

August 31,
1986
Flight from Mexico City to LAX was clipped on the tail by a small airplane flying from Torrance to Big Bear Lake. The damaged passenger plane crashed into the backyard of a
house in the Los Angeles suburb of Cerritos; the Piper crashed into empty schoolyard at Cerritos Elementary School.

Accident deemed to be pilot error on the part of the Piper, who climbed into Los Angeles Terminal Control Area airspace without clearance, and on Air Traffic Control, who did not notice this incursion as they were distracted by another unauthorized private flight entering controlled airspace at about the same time. Neither pilot saw the other aircraft although both were in visual range. As a result, FAA required all commercial jets in U.S. airspace to be equipped with a TCAS, and all light aircraft operating in dense airspaces to be equipped with Mode C transponders that report altitude.

All 58 passengers and 6 crew
members of the DC-9 died.

The pilot and 2 passengers in the
Piper died.
15 people on the ground died and 8
were injured.

August 11,
1987
Airplanes nearly collided approximately 2.5 miles east of the Santa Monica Very High Frequency Omnidirectional Range
Station (VOR). Co-pilot of passenger craft saw other aircraft and took evasive actions at about 7,400 feet above mean sea level. Aircraft were probably about 100 feet from each other.

No injuries to all 46 onboard.

December 7,
1987
Flight from LAX to San Francisco (SFO) was hijacked by
passenger and crashed in San Luis Obispo County, near
All 43 onboard died.

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Date Description Casualties
Cayucos. Perpetrator was a disgruntled employee of airline company. Safety measures were implemented to prevent this in the future.

February 1,
1991
Airplanes collided at LAX. One plane was told to taxi into takeoff position while the other aircraft was landing on same runway. Accident deemed to have likely been caused by a series of operational procedures and issues including that LAX’s ground radar system was not working at the time, there was a blind spot from the control tower to area where the aircraft was waiting to take off, aircrafts on runways were not required to turn on all their external lights until rolling for takeoff, and flaws in the system by which local controllers passed flight progress strips among them. Crash led to National Transportation Safety Board (NTSB) to recommend using
different runways for takeoffs and landings; however, this was implemented only after incident in 2004 (see below). LAX built a new control tower in more central location and
rectified operational issues in control tower, lights on planes, and ground radar system.

All 12 onboard the SkyWest aircraft
died.
23 of the 89 onboard the USAir
aircraft died, mostly due to
asphyxiation from the fire that began
after crash; 29 were injured. 66
survivors.

April 23,
1994
Flight from Santa Maria, CA to LAX encountered wake
turbulence from another airplane ahead of it while descending towards LAX, north of Santa Monica VOR. After encountering turbulence, the plane rolled to the left and then became inverted. Pilot righted the plane and continued on to land without further incidents. Radar data showed that airplanes were 4.47 miles apart, less than the 5 nautical miles required when aircraft are operating directly behind a heavy jet aircraft such as a 747.
1 passenger reported minor injuries.

January 31,
2000
Flight from Puerto Vallarta, Mexico to Seattle, Washington with stopover in San Francisco crashed into Pacific Ocean north of Anacapa Island, off the coast of Ventura. NTSB review found inadequate maintenance led to excessive wear and
failure of flight control systems, with the aircraft experiencing loss of pitch control. The pilots were attempting to divert to LAX when the stabilizer assembly suffered complete failure and plane crashed at high speed into ocean.

All 88 onboard died.

August 19,
2004
Airplane landing at LAX passed about 200 feet above another plane holding on the same runway. As a result of this incident, LAX implemented an earlier recommendation by the NTSB to designate and use separate runways for landings and takeoffs.

No injuries.

February 20,
2005
Innermost left engine of plane from LAX to London Heathrow burst into flames immediately after taking off. Pilots chose to continue on three engines rather than dumping 70 tons of fuel, and performed successful emergency landing at Manchester Airport in England.

No injuries.

September
21, 2005
Flight from Burbank to Kennedy International Airport in New York City requested to make emergency landing at LAX after nose landing gear jammed in abnormal position – nose wheel was rotated 90 degrees to the left. Landing occurred at LAX to take advantage of long runway and modern safety equipment.

Pilot flew in figure 8 pattern for >2 hours to burn fuel. Nose gear generated sparks and flames upon landing but aircraft was otherwise undamaged.

No injuries to all 140 passengers and
6 crew members.

December
19, 2005
Flight flying from LAX to Frankfurt International Airport in Germany experienced failure of four right body landing gear tires during takeoff. Debris was reported on the runway by a member of the airport operations crew. Crew dumped the fuel No injuries.

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Date Description Casualties
and returned to LAX.

October 19,
2006
Flight between LAX and Mexico City, Mexico. After entering Mexican airspace, the flight crew was alerted to a System B hydraulic failure. Crew opted to return to LAX. On their final 5-mile approach to LAX, after extending the landing gear, the System A hydraulic system issued a low-pressure alert, the pressure gage reported a reading of 0 psi and the airplane became difficult to control in the mechanical reversion mode.

The crew were able to land the plane with no incident,
however. Examination of the airplane found the first event was the result of catastrophic failure of the engine driven pump, and that the second event was due to a spoiler hydraulic line that had fractured.

No injuries.

April 12,
2007
Flight from Kennedy Airport in New York experienced
moderate turbulence while descending into LAX. Flight deck had received information about turbulence below 12,000 feet, but they experienced a jolt at about 15,500 feet. Crew had already secured the cabin but were not seated. No damage to the aircraft.

No injuries to the 2 pilots and 104
passengers onboard. Minor injuries to
5 flight attendants and serious injuries
to 1 flight attendant. All 6 received
medical attention after landing.

June 29,
2007
Departing flight from LAX to Beijing, China, experienced burst tires and wheel disintegration during takeoff, causing minor damage to the airplane. While taxiing for departure, one of the tires hit a foreign object which cut the tire with resultant loss of pressure. During takeoff roll, two other tires burst and their associated wheels fractured. After dumping fuel, the airplane returned to LAX and landed uneventfully.

No injuries to the 237 people
onboard.

August 16,
2007
Two aircraft came to within 37 feet of each other while taxiing at LAX. The near-accident was the result of the controller’s failure to coordinate with the tower local controller prior to providing taxiing instructions that allowed the first aircraft to cross an active runway while the other plane was departing.

No injuries reported to 142.

December
26, 2008
Flight between LAX and Dallas/Fort Worth overran and
impacted a tug that was positioning the airplane during pushback from the terminal. First officer advanced the left engine throttle with sustained application of high thrust, causing the airplane to impact the tug. Airplane sustained damage to the radome and forward fuselage.

None of the 129 people onboard, nor
the tug operator, was injured.

May 21,
2009
Flight from LAX to San Diego, while leaving the terminal hub, taxied into a parked and unoccupied airplane. The moving airplane experienced substantial damage to the left horizontal stabilizer, and the parked plane experienced substantial damage to the right horizontal stabilizer. The parked airplane had been improperly parked with the right wing tip and
horizontal stabilizer outside the safety lines.

No injuries to any of the 47 people
onboard.

September 8,
2009
Flight from Las Vegas, while landing at LAX, experienced a failure of the inboard axle on the right main landing gear. The captain reported that the airplane swerved during the landing rollout so he stopped the plane on the taxiway. A pilot on another aircraft reported seeing a tire depart the airplane. The right inboard wheel and brake assembly separated from the aircraft and were found on the north side of the runway.

Airplane was taxied off the runway and the passengers
deplaned using stairs and were taken to the terminal by bus.

No injuries to the 142 people
onboard.

September 4,
2010
Flight to Las Vegas, Nevada departing from LAX passed within 750 feet laterally and 200 feet vertically of a helicopter flying out of UCLA Medical Center. Investigation found that
controller handling the helicopter did not issue clear and No injuries to 129 onboard.

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Date Description Casualties
timely instructions and the helicopter pilot did not react quickly to the instructions provided.

November 8,
2010
Flight between Redding, California and LAX hit a bird
approximately 18 nautical miles north of LAX at an altitude of 7,500 ft. Bird hit the leading edge of the right wing, causing a 12-inch hole in the wing. Crew never saw the bird before it hit the airplane. Crew declared an emergency and made
uneventful landing at LAX.

No injuries to 77 onboard.

January 3,
2011
Flight from LAX to Toronto, Canada experienced a tail strike during takeoff at LAX. Flight landed in Ontario uneventfully, with damage to airplane tail skid discovered then. Additional review of the airplane found substantial damage to the aft pressure bulkhead. The probable cause was deemed to be
early rotation of the airplane to an angle at which the fuselage struck the runway. The early rotation was the pilot’s response to a keystroke entry error by the first officer who manually entered takeoff data for the assigned runway.

No injuries to 165 onboard.

July 11,
2014
Flight to Atlanta, Georgia, while climbing out of LAX
experienced a fire on the left No. 1 engine. Crew declared emergency, shut down the affected engine, and returned to LAX where they made a successful overweight single-engine landing. Review of the engine found that fuel had leaked from the fuel/oil heat exchanger and arcing of the power feeder cables had ignited the fuel. The arc was the result of chaffed cables that exposed the electrical wire, which in turn
contacted a metal bracket. Airline inspected their entire fleet of Boeings 767 following this incident and corrected any power feeder cables that had been misrouted.

No injuries to 208 onboard.

March 6,
2017
A plane taxiing for takeoff at LAX experienced an abrupt stop with the parking brake set. The lead flight attendant, who was performing safety checks, was seriously injured. Plane
returned to gate. Maintenance personnel examined the
airplane and found that the circuit breaker for the parking brake electrical control valve had popped, causing the
airplane to stop suddenly.
1 person injured out of 121 onboard.

September
12, 2017
Passenger airplane sustained minor damage when its righthand winglet scraped the stabilizer of another plane waiting to be towed to a gate. The tail of the second aircraft protruded beyond the while lines and the other crew misjudged the amount of clearance.

No injuries to any of the occupants in
both aircrafts.

August 13,
2018
Flight from Kahului, Hawaii to LAX experienced a tail strike during landing. The crew reported receiving a ground
proximity warning system (GPWS) fail message and electronic automatic altitude callouts were not provided by the airplane system. Aircraft touched down firmly, bounced, and the pitch altitude increased, causing the tail section to contact the runway. Failure of the radio altimeter was deemed to be the result of flying over calm/flat water.

No injuries to the 197 onboard.

January 14,
2020
Flight from LAX to Shanghai Pudong International Airport reported engine problems shortly after takeoff and requested emergency landing. Prior to landing, pilots dumped fuel over a 5-mile area in Los Angeles including 5 elementary schools and 1 high school. Most affected was Park Avenue Elementary School in Cudahy and schools in South Gate. Pilots did not follow procedures to dump fuel over unpopulated areas, open ocean, or at higher altitudes, prompting an investigation by the FAA.

Lung and skin irritation to at least 56
people in the ground including
several school children doused with
jet fuel.

Aircraft landed safely; no injuries to
those onboard.

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Date Description Casualties
January 26,
2020
Helicopter flying from Santa Ana to Camarillo crashed in Calabasas. Accident deemed to be pilot error - when
helicopter entered area with low cloud cover, the pilot lost sense of orientation and lost control.

All 9 onboard died.

February 3,
2020
Domestic cargo flight on its way from LAX to Honolulu,
Hawaii collided with a garbage bin during its takeoff roll. The garbage dumpster was blown onto the runway by winds that were gusting to 28 knots. The moving dumpster impacted the airplane causing substantial damage to the aircraft. Takeoff was aborted.

No injuries to the 2 crew members
and 5 passengers.

September
22, 2022
Flight 3 on its way from LAX to Honolulu, Hawaii experienced a pitch anomaly while climbing out of LAX. Crew declared an emergency and after dumping fuel offshore, returned to LAX without further incident.

No injuries to all 290 onboard.

December 4,
2024
Flight from LAX to Brisbane International Airport, Australia reported that while en route, approximately 1828 km WSW of LAX, sparks were observed from the No. 2 engine. Crew
returned to LAX and during approach, a bang was heard and the engine stalled. Aircraft landed without further incident.

Metal was found in the tail pipe of the damaged engine.

No injuries reported.

A summary of incidents and accidents that have occurred in and near Santa Monica between 1964 and 2023 inclusive as a result of aviation operations at SMO is provided in Table 13-3 below. The list includes aircraft to or from SMO that experienced incidents at SMO, or crashed nearby, in Santa Monica, the beach, Santa Monica Bay, Venice, Los Angeles, and Malibu. Other accidents associated with aircraft that either originated or were headed to SMO but that crashed or emergency-landed elsewhere are not included here. Some incidents in the 1960s may be missing as the records from that time period are incomplete and do not mention the airports involved.

Table 13-3: Aircraft Incidents Reported for SMO between 1964 and 202414F 15 Year of
Incident
Date of
Incident
Injury Level
Totals Fatal Serious Minor Highest
Injury Level
1964
January 11
March 18
March 21
May 13
September 26
October 18
November 3
November 25
December 19
December 27
0 0 0 None
10 incidents;
1 fatality;
1 injury
0 0 0 None
0 0 0 None
1 0 0 Fatal
0 0 0 None
0 0 0 None
0 0 0 None
0 0 1 Minor
0 0 0 None
0 0 0 None
1965
January 24
June 27
September 9
October 3
0 0 0 None
6 incidents;
2 fatalities
0 0 0 None
2 0 0 Fatal
0 0 0 None

15 Based on data downloaded from https://www.ntsb.gov/, accessed in March-June 2025, with searches for Santa Monica, Los Angeles, Venice, and Malibu. Additional information obtained from https://friendsofsunsetpark.org/airport/safety-concerns/, also accessed in March-June 2025.

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Year of
Incident
Date of
Incident
Injury Level
Totals Fatal Serious Minor Highest
Injury Level
November 4
December 12
0 0 0 None
0 0 0 None
1966
January 12
January 25
March 2
March 26
April 6
April 13
May 22
August 6
August 2
October 6
October 14
November 12
November 25
0 0 0 None
13 incidents;
2 fatalities
0 0 0 None
0 0 0 None
0 0 0 None
0 0 0 None
0 0 0 None
0 0 0 None
2 0 0 Fatal
0 0 0 None
0 0 0 None
0 0 0 None
0 0 0 None
0 0 0 None
1967
February 21
April 14
July 26
October 18
0 0 0 None
4 incidents;
7 fatalities
0 0 0 None
3 0 0 Fatal
4 0 0 Fatal
1968
May 24
August 13
October 2
October 28
0 0 4 Minor
4 incidents;
1 fatality;
4 injuries
0 0 0 None
1 0 0 Fatal
0 0 0 None
1969 May 23 0 0 0 None 1 incident; 0 injuries
1970
January 2
March 6
March 17
March 18
June 24
0 0 1 Minor
5 incidents;
2 fatalities; 3 injuries
0 0 0 None
0 2 0 Serious
0 0 0 None
2 0 0 Fatal
1973 May 14
August 21
1 0 0 Fatal 2 incidents; 1 fatality;
0 0 1 Minor 1 injury
1974 August 8 1 0 00 Fatal 1 incident; 1 fatality
1975
February 2
March 12
July 1
November 16
December 22
0 0 0 None
5 incidents;
0 injuries
0 0 0 None
0 0 0 None
0 0 0 None
0 0 0 None
1976 June 21
October 21
0 0 0 None 2 incidents;
2 0 0 Fatal 2 fatalities
1977
June 14
August 20
September 9
December 30
0 0 0 None 4 incidents;
1 fatality;
4 injuries
0 0 2 Minor
1 0 1 Fatal
0 0 2 Minor
1978 April 16
May 13
0 0 0 None 2 incidents;
0 0 2 Minor 2 injuries
1979 August 31 0 0 1 Minor 1 incident; 1 injury
1980
February 28
March 23
May 15
August 2
August 8
0 1 0 Serious
5 incidents;
1 fatality
2 injuries
0 0 0 None
0 0 0 None
0 0 1 Minor
1 0 0 Fatal
1981 April 7
May 6
0 1 0 Serious 5 incidents;
0 0 0 None 1 injury
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Year of
Incident
Date of
Incident
Injury Level
Totals Fatal Serious Minor Highest
Injury Level
May 9
May 21
November 8
0 0 0 None
0 0 0 None
0 0 0 None
1982
January 19
April 10
July 5
August 22
September 21
November 2
0 0 0 None
6 incidents;
1 injury
0 0 0 None
0 0 1 Minor
1 0 0 Fatal
0 0 0 None
0 0 0 None
1987
May 17
June 18
August 11
September 22
0 2 1 Serious
4 incidents;
3 injuries
0 0 0 None
0 0 0 None
0 0 0 None
1988 March 27 0 0 0 None 1 incident; 0 injuries
1989
July 7
July 9
August 6
October 26
0 0 0 None
4 incidents; 4 injuries 0 1 1 Serious
0 0 0 None
0 0 2 Minor
1990
February 26
March 10
August 2
August 24
1 0 0 Fatal
4 incidents;
5 fatalities
4 0 0 Fatal
0 0 0 None
0 0 0 None
1991 February 24
October 4
0 0 0 None 2 incidents; 0 injuries 0 0 0 None
1992
January 18
March 9
September 5
2 0 0 Fatal 3 incidents;
2 fatalities
4 injuries
0 0 0 None
0 0 4 Minor
1993
April 29
July 2
November 26
December 7
0 0 0 None 4 incidents;
3 fatalities;
1 injury
0 0 1 Minor
3 0 0 Fatal
0 0 0 None
1994
March 11
April 20
April 23
November 22
1 1 0 Fatal 4 incidents;
2 fatalities
2 injuries
1 0 0 Fatal
0 0 1 Minor
0 0 0 None
1995 May 7
July 13
0 1 0 Serious 2 incidents;
0 0 0 None 1 injury
1997 February 2 0 0 2 Minor 1 incident; 2 injuries
1999
June 16
July 11
September 23
0 0 0 None 3 incidents;
3 injuries 0 0 2 Minor
0 0 1 Minor
2001 March 28
November 13
3 0 0 Fatal 2 incidents;
2 0 0 Fatal 5 fatalities
2003 June 6 5 7 0 Fatal
2004 March 16
December 4
2 0 0 Fatal 2 incidents;
0 0 0 None 2 fatalities
2006 March 13 2 0 0 Fatal 1 incident; 2 fatalities
2008 January 13
October 7
0 0 0 None 2 incidents; 1 fatality;
1 1 0 Fatal 1 injury
2009 January 28
August 2
2 0 0 Fatal 2 incidents; 1 injury;
0 1 0 Serious 2 fatalities
2010 July 1 1 0 0 Fatal 1 incident; 1 fatality
2011 August 29 0 1 2 Serious 1 incident; 3 injuries
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Year of
Incident
Date of
Incident
Injury Level
Totals Fatal Serious Minor Highest
Injury Level
2012 August 10 1 0 0 Fatal 1 incident; 1 fatality
2013 April 12
September 29
0 0 0 None 2 incidents; 4 fatalities 4 0 0 Fatal
2014 April 18
October 26
0 0 0 None 2 incidents; 0 injuries 0 0 0 None
2015 March 5 0 1 0 Serious 1 incident; 1 injury
2016 May 22 0 0 0 None 1 incident; 0 injuries
2017 March 12 0 0 0 None 1 incident; 0 injuries
2018 February 11 0 0 0 None 1 incident; 0 injuries
2019 December 27 0 0 0 None 1 incident; 0 injuries
2021 January 2
August 12
0 0 0 None 2 incidents; 0 injuries 0 0 0 None
2022 September 8
December 22
2 0 0 Fatal 2 incidents; 1 injury;
1 0 1 Fatal 3 fatalities
2023 June 5 0 0 0 None 1 incident; 0 injuries
Grand Totals 60 20 35 135 incidents
As shown on Table 13-3, between 1964 and 2024 inclusive, about 2.3 accidents and incidents per year, on average, have involved SMO aircraft, based on records from the National Transportation Safety Board, with some years having no accidents or incidents, and other years having multiple events. Note that compared to the 20th century, the number of incidents and accidents has decreased significantly in the 21st century, although the number of fatalities and injuries has not decreased much. Thus, in the 36-year period between 1964 and 1999 inclusive, a total of 108 accidents and incidents were reported for SMO, with these resulting in 34 fatalities and 41 injuries, 9 of those serious. Between the years 2000 and 2024 inclusive, there were 27 incidents and accidents involving aircraft leaving or landing at SMO, with the accidents accounting for 26 fatalities and 14 injuries, 11 of those serious. Using the data from Table 13-1 for the years between 2018 and 2023, the number of accidents and incidents that occurred in those six years relative to the total number of flight operations at SMO amounts to about 1.7 events per 100,000 operations (7 events out of 404,462 flight operations).

The record furthermore shows that the incidents and accidents generally occurred during takeoff or landing, on or just off the end of the runway centerline, although some occurred within a short radius (generally within 5 miles) of the airport. Most of the accidents and incidents reported at SMO resulted from pilot error or equipment failure. Offsite accidents include aircraft that landed or crashed in golf courses, residential areas, or over the Pacific Ocean, in the Santa Monica Bay. Based on the records reviewed, accidents over residential areas, with aircraft crashing into residential homes, are responsible for 1 fatality and 9 injuries of individuals on the ground. The most significant of these is the accident on June 6, 2003, when an airplane with four people onboard headed to Las Vegas crashed into a three-story apartment building in the Fairfax district of Los Angeles. All four on board and one person on the ground died, and seven people on the ground were injured. Note that given that only small aircraft fly to and from SMO, accidents related to SMO operations have always involved only a small group of people, akin to vehicular accidents involving passenger cars.

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REGULATORY SETTING
Under the 2017 Settlement Agreement and Consent Decree15F 16 between the Federal Aviation
Administration (FAA) and the City of Santa Monica, the City is obligated to operate SMO until December 31, 2028 in accordance with the terms of the Agreement and consistent with all applicable federal laws and regulations for general aviation airports. Such rules include the City’s obligation to offer no less than a three-year lease term to new and existing aeronautical service provider tenants, subject to their ability to meet the requirements of the City’s Commercial Minimum Standards for Aeronautical Service Providers. Furthermore, if space is available at SMO to accommodate their operations, and if all regulatory requirements are met, then aeronautical service providers such as flight schools and aircraft mechanics are entitled to operate at SMO up to and until the end of 2028. For the duration of the Consent Decree, the City may not unreasonably limit or prohibit aeronautical uses at SMO. Federal, state and local regulations governing the operation of airports in general, and SMO in particular, are summarized below.

Airports are the equivalent of an industrial zone where a variety of hazardous operations occur and materials are stored, managed and used in the delivery of aviation services. The type and intensity of the land uses placed in proximity to airports, and especially specific operations, can result in increased safety hazards, and in the less-catastrophic but not-less damaging effects of excessive noise and poor air quality. It is essential that potential adverse impacts and incompatibilities are given careful consideration. “Airport land use compatibility is the reconciliation of how land development and airports function together.”16F
17 The potential of airport land uses and operations to raise issues of safety and compatibility with other land uses is well understood. Federal, state and local regulations have guided and continue to guide and direct airport design and airport operations to maximize the long-term viability of airports in general, minimize the encroachment of potentially incompatible land uses, and ensure safe and complementary aviation services wherever possible. The regulatory requirements that address the three major prongs of airport compatibility—land use, operations and noise—are briefly summarized below.

Airport Land Use Compatibility Planning Requirements
In California, the development and operations of airports, including airport land use compatibility planning, is regulated in part by Sections 21670 – 21679.5 of the Public Utilities Code (PUC)17F 18, with
the California Department of Transportation (Caltrans), Division of Aeronautics, administering the PUC statutes. The PUC outlines the statutory requirements for county-based Airport Land Use Commissions (ALUCs), and the preparation of Airport Land Use Compatibility Plans (ALUCPs). An ALUCP describes the county airports, either individually or as a group, with an emphasis on operations, and provides projections for future levels of operation and associated land use

16 For more information, refer to
https://www.santamonica.gov/media/Document%20Library/Detail/Future%20of%20Santa%20Monica%20Airport %20Project/Legal%20Documents/Consent%20Decree.pdf and
https://santamonicacityca.iqm2.com/Citizens/Detail_LegiFile.aspx?Frame=&MeetingID=1088&MediaPosition=&I D=2367&CssClass= 17 California Airport Land Use Planning Handbook, prepared by Caltrans Division of Aeronautics. October 2011, available from https://dot.ca.gov/-/media/dotmedia/programs/aeronautics/documents/californiaairportlanduseplanninghandbook-a11y.pdf. 18 California Public Utilities Code (PUC), Division 9, Part 1, Chapter 4, Article 3.5, Airport Land Use Commissions, PUC Sections 21670 – 21679.5.

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constraints, including community noise.

Furthermore, the Division of Aeronautics California Airport Land Use Planning Handbook (Handbook18F
19) provides guidance for conducting airport land use compatibility planning, including the identification of essential elements that should be covered when preparing an ALUCP (PUC Sections 21674.5 and 21674.7). Essentially, the Handbook is a valuable source of information that identifies the requirements and procedures for preparing, adopting, and amending effective compatibility planning documents, and defines exemptions where applicable. This Handbook is referenced often in this report.

Airport Operations
Operational safety is primarily focused on aircraft operations, including takeoffs and landings, but also taxiing, fueling, and aircraft tie-down and storage. A variety of federal, state and local regulations address airport operational hazards by providing policies that apply to airport land use planning efforts, development near an airport, and the management of airport-related safety risks.

Some of these regulations are discussed further below.

At the federal level, the FAA is primarily responsible for ensuring the safe and efficient use of navigable airspace, and the preservation of such airspace (Title 14 of the Code of Federal Regulations [CFR] Part 77). As a result, this document establishes standards for determining obstructions in navigable airspace, such as the construction or alteration of structures or objects more than a given height near an airport and the airport’s landing and takeoff approaches.

The FAA has also developed a safety management system (SMS) that includes procedures, practices, and policies for the management of safety risk that is aimed at aviation products and service providers for which the FAA has regulatory authority and safety oversight responsibility (FAA Order 8000.369C19F
20). Entities covered under this order include airports, manufacturers, operators, maintenance organizations, training organizations, and air traffic service providers, among others.

The four key components are safety-centric and address policy, risk management, safety assurance and safety promotion (Figure 13-4). Each component is briefly described below.

Safety Policy: Safety policy must clearly demonstrate management’s commitment to constantly improving operational airport safety. Policy must reflect goals and objectives, define methods and processes, and the organizational structure. Safety policy also sets forth reporting and issues resolution, and accountability.

Safety Risk Management (SRM): This component determines the need for, and adequacy of, new or revised risk controls based on the assessment of acceptable risk. It establishes a formal process that describes and analyzes the system or subsystem being managed, identifies the hazards associated with that system or subsystem, assesses the risk, analyzes the risk parameters, sets forth system-appropriate procedures to control the risk, and tracks and monitors the mitigations and controls implemented to ensure that they work as intended.

19 California Airport Land Use Planning Handbook, prepared by Caltrans Division of Aeronautics. October 2011, available from https://dot.ca.gov/-/media/dotmedia/programs/aeronautics/documents/californiaairportlanduseplanninghandbook-a11y.pdf. 20 Available at https://www.faa.gov/documentLibrary/media/Order/Order_8000.369C.pdf Local Hazard Mitigation Plan Section 13
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Safety Assurance: The safety assurance process evaluates the ongoing effectiveness of implemented risk control strategies and supports the identification of new hazards. It includes process management functions that systematically provide confidence that organizational actions and implementation strategies meet or exceed safety requirements. The safety assurance process ensures compliance with the safety management plan and FAA orders, standards, policies, and directives. This process also provides insight and analysis regarding methods/opportunities for improving safety and minimizing risk.

Safety Promotion: Safety must be a culture and be integral to operations management. It includes staff training, communication, and other actions to create a positive safety culture within all levels of the organization. Associated training includes safety promotion activities within the system framework including staff training, advocating/strengthening a positive safety culture, developing system and safety communications and situational awareness. It also involves matching competency requirements to system requirements, disseminating safety lessons learned, and reinforcing the commitment that everyone has a role in promoting safety.

Figure 13-4: The Four Safety Management System (SMS) Components Source: FAA Order 8000.369
Other federal regulations managed by the FAA that pertain to municipal airports such as SMO are contained in Title 14 Part 152 of the CFR (14 CFR Part 152). These regulations refer to the administration of the Airport Improvement Program (AIP). The AIP provides federal grants for airport infrastructure projects, especially improvements meant to increase safety, capacity and/or security, and reduce environmental concerns. It is important to note that the City of Santa Monica does not participate in the AIP program, but has managed a robust Capital Improvement Program to improve safety, capacity and security and to reduce environmental concerns related to SMO operations.

In addition to these FAA regulations and standards, both Caltrans’ Division of Aeronautics and Los Angeles County ALUC have policies and criteria for local agencies to apply to airport land use planning efforts and development projects near an airport. Proper safety standards and airspace protection regulations are meant to minimize the number of people in the vicinity of an airport that Local Hazard Mitigation Plan Section 13
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are exposed to the risks associated with potential aircraft accidents, and to avoid flight hazards that interfere with aircraft navigation.20F
21 The primary ground strategy is to limit the intensity of land uses near the airport by minimizing residential and non-residential densities and activities that attract people to locations most susceptible to an off-airport aircraft accident. Certain risk-sensitive uses, such as schools21F
22 and hospitals, and above-ground storage of flammable or hazardous materials, should be avoided regardless of the number of people involved.22F 23 To that end, ALUCs adopt planning boundaries around airports that delineate those areas subject to safety hazards and noise impacts. These safety compatibility zones, or airport influence zones, include height restriction areas, the approach surface, and runway protection zones. Based on the Los Angeles County ALUCP, the approach surface is an imaginary inclined plane beginning at the end of the primary surface and extending outward to distances of up to 10 miles, depending on runway use. The approach surface governs the height of objects on or near the airport by prohibiting objects from penetrating or extending above the approach surface.

Runway protection zones (RPZs) are trapezoidal-shaped areas at ground level, just beyond each end of the runway, that provide for the unobstructed passage of landing aircraft through the airspace above. The dimensions of RPZs vary depending upon the type of landing approach that is available (visual, non-precision, precision) and the characteristics of the aircraft (size, weight, approach speed). RPZs should be kept free of all obstructions, such as structures, objects and even people. To manage this, control of the RPZ by the airport owner is essential, either by outright ownership or aviation easements to ensure compliance. Other designated areas around airport runways designed to enhance safety include Inner Safety Zones (ISZs), Inner Turning Zones (ITZs), Outer Approach/Departure Safety Zones (OSZs), Sideline Safety Zones (SSZs) and Traffic Pattern Zones (TPZs). Not all these safety zones are used at all airports.

The Airport Influence Zone (AIZ) and designated safety zones around SMO are shown on Figure 13-5. The AIZ is the designated area around the airport where airport-related activities can have an impact on nearby land uses. These concerns include not only safety but noise. The designated Runway Protection Zone (RPZ) extends 150 feet from either end of the runway,23F 24 whereas the
rectangular SMO Inner Safety Zone (ISZ) extends along the runway centerline and beyond the RPZ for 2,600± feet. For additional discussion regarding these safety zones as they pertain to land uses in and near SMO, refer to the hazard identification section below.

21 California Airport Land Use Planning Handbook, prepared by Caltrans Division of Aeronautics. October 2011, available from https://dot.ca.gov/-/media/dotmedia/programs/aeronautics/documents/californiaairportlanduseplanninghandbook-a11y.pdf. 22 California Education Code 17215 requires that new school sites within 2 miles of an airport runway need to be investigated by Caltrans. If Caltrans does not favor the placement of a school at that location, no state or local funds can be used for site acquisition or building construction at that site. Similar requirements for community college sites are established in Education Code Section 81033. 23 For additional information on federal regulations regarding airspace safety, refer to Federal Aviation Regulation (FAR) Part 77 and the California Public Utilities Code Sections 21658 and 21659. 24 As defined by the FAA, a Runway Protection Zone is an area off the runway end to enhance the protection of people and property on the ground.

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Figure 13-5: Airport Influence Zones
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Aviation Noise
Aircraft-generated noise is one of the most basic airport land use compatibility concerns and can be perceived to be the most significant of the adverse impacts associated with an airport. Aircraft noise, usually the most geographically extensive form of airport impact, is dependent on several attributes, including the aircraft type, timing, and frequency of flights. Addressing aircraft noise and its cumulative impacts requires continual collaboration and coordination among pilots, airport operators, Federal Aviation Administration (FAA), Division of Aeronautics, ALUCs, local governments, and other constituents.

At the federal level, the impact of aircraft noise on communities surrounding airports is addressed in the Aviation Safety and Noise Abatement Act (ASNAA) of 1979. The ASNAA directed the FAA to establish a uniform system for measuring noise, assess its impact, and identify land uses that are compatible with various levels of aircraft noise exposure. Implementation of the requirements in the ASNAA is administered by the FAA under two main programs: 1) Airport Noise Compatibility Planning (14 CFR Part 150), and 2) Airport Noise and Access Restrictions (14 CFR Part 161). Both of these programs aim to minimize the impacts of airport noise on the surrounding communities.

Federal Aviation Regulation (FAR) Part 150 was first adopted as an interim rule in February 1981, and has been revised several times, most recently in March 1988 to include freestanding heliports.

The program focuses on noise compatibility planning, establishing guidelines for airports to develop noise exposure maps and mitigation measures that emphasize land use planning. The core of 14 CFR Part 150 is the day-night average sound level (DNL) with a threshold of 65 decibels (dB)24F 25, the
level at which aircraft noise is considered to significantly impact residential areas. Figure 13-6 shows how 65 dB compares to other local average ambient noise levels.

As required by the ASNAA, Part 150 regulations apply to any “public use airport” as defined by Section 502 (17) of the Airport and Airway Improvement Act of 1982. The regulations provide a single system of measuring aircraft noise and a single system for determining the exposure of individuals to noise in the vicinity of airports. The regulations also establish a standardized airport noise compatibility planning program including:
• Voluntary development and submission to the FAA of noise exposure maps (NEMs) and noise compatibility programs (NCPs) by airport owners;
• Standard noise measurement methodologies and units;
• Identification of land uses that are normally compatible (or incompatible) with various levels of aircraft noise around airports; and
• The procedures and criteria for preparation and submission of NEMs and NCPs.

25 According to a report by Tang, R.Y., published on September 27, 2021 available from https://www.congress.gov/crs-product/R46920, accessed on July 2, 2025, the FAA surveyed 10,000 people living near 20 representative airports and found that aircraft noise becomes significantly annoying at levels as low as DNL 50-55 dB. Based on these findings, the DNL 65 dB threshold may no longer be an adequate guide to federal policy, and may require the FAA to adjust the threshold to a lower level.

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Figure 13-6: Typical Noise Levels
Note: Local average ambient noise levels are defined by an average of the ambient background noise levels and peak noise events. Peak noise events may include sporadic increases in noise levels from street noise, aircraft overflights, and other temporary increase in noise.

Source: Santa Monica Airport Calendar Year 2016 Annual Operations Report; Appendix E.

Although airport operators are not required to participate in this program and thus the submission of these maps is completely voluntary, federal grants for noise abatement projects generally require an approved Part 150 NCP. ASNAA does not allow the federal government to interfere with or override local government zoning, subdivision building, and health authority.

Typically, recommended noise abatement measures fall into three categories:

1. Operational measures such as changes in runway use or changes in flight-track location;

2. Preventive measures such as compatible land use zoning or noise overlay zoning within offairport noise exposure areas; and

3. Remedial measures such as the purchasing of properties or sound insulating of residential properties exposed to significant aircraft noise.

The Airport Noise and Access Restrictions (14 CFR Part 161) were established in response to the Airport Noise and Capacity Act of 1990. Under these regulations airports may implement noiserelated restrictions on aircraft operations (such as limiting certain types of aircraft) based on a voluntary agreement with aircraft operators or by obtaining FAA approval of mandatory noise-based restrictions. Given that SMO’s 65db contours fall within the airport environment (within airport property), the City does not benefit from either Part 150 or Part 161 studies.

Airports may also implement voluntary noise abatement procedures, such as the “Fly Neighborly Program” used by SMO that is described further later in this document. These voluntary programs ask aircraft operators to adjust their flight procedures and routes to minimize noise impact on the communities or neighborhoods adjacent to the airport.

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At the state level, Section 21669 of the PUC (the State Aeronautics Act) requires Caltrans to adopt noise standards applicable to all airports operating under a state permit, as long as those standards are not prohibited by federal law. The airport noise standards promulgated by PUC Section 21669 are set forth in Section 5000 et seq. of Title 21, Division 2.5, Chapter 6 of the California Code of Regulations (CCR Title 21, Division 2.5, Chapter 6). These regulations indicate that 1) airport proprietors25F
26 have the power to impose noise ceilings and other limitations on the use of the airport, and 2) that the state has the power to act to an extent not prohibited by federal law.

In Section 5006 of CCR Title 21, Division 2.5, Chapter 56, the regulations state that:
“The level of noise acceptable to a reasonable person residing in the vicinity of an airport is established as a community noise equivalent level (CNEL) value of 65 dB for purposes of these regulations. This criterion level has been chosen for reasonable persons residing in urban residential areas where houses are of typical California construction and may have windows partially open. It has been selected with reference to speech, sleep and community reaction.”
Santa Monica implements several airport noise regulations, which are some of the strictest in the United States. Specifically, airport operations at SMO must comply with the City’s Aircraft Noise Abatement Code [Santa Monica Municipal Code (SMMC) Section 10.04.04.080(b)], which establishes a maximum noise level, nighttime departure curfew, and flight procedures designed to mitigate noise. These are described in more detail below:
• Maximum noise level: Aircraft are prohibited from exceeding a Single Event Noise Exposure Level (SENEL) of 95.0 dBA26F
27 at designated noise monitoring stations. This is discussed further below.
• Night departure curfew: Under this night departure curfew, no takeoffs or engine starts, including auxiliary power unit (APU), are permitted between 11 P.M. and 7 A.M. Monday through Friday, or until 8 A.M. on weekends and holidays. Exceptions are only allowed for bona fide medical or public safety flights.
• Operational Limitations: Training operations such as touch-and-go, stop-and-go, and low approaches are prohibited on weekends, holidays, and weekdays from one-half hour after sunset until 7 A.M. the following day. Moreover, intersection departures, formation takeoffs and landings, and simulated landings opposite the direction of take-off are prohibited. Dual wheel aircraft in excess of 60,000 pounds need prior permission from the Airport Director. • Helicopter Training: Helicopter training is prohibited.

26 An airport proprietor is the holder of an airport permit issued by the Department of Transportation pursuant to Article 3, Chapter 4, Part 1, Division 9 of the PUC. 27 dBA refers to A-weighted decibels, a measurement that factors in the human ear's varying sensitivity to different frequencies, and is thus considered a more accurate representation of perceived loudness. For example, the human ear is less sensitive to lower-frequency sounds than high audio frequencies. dB, or decibels, is a broader term representing the ratio of two signal strengths on a logarithmic scale and can refer to various measurement types with different reference points.

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Figure 13-7: Single Event Noise Exposure Level (SENEL)
Note: As an aircraft approaches a noise receptor, the sound of the aircraft begins to rise above the threshold level. The closer the aircraft gets, the louder it is until the aircraft is at its closest point directly overhead. As the aircraft passes, the noise level decreases until the sound settles below the threshold level. Such a history of a flyover is plotted in this graph. The highest noise level reached during the flyover is called the “Maximum Noise level,” or LMax. The area in the same graph within 10 dBA of the Lmax is the area from which the Single Event Noise Exposure Level (SENEL) is computed. This metric takes into account the maximum noise level and the duration of the event. The SENEL value is always higher than the Lmax value for aircraft events.

Source: Santa Monica Airport Calendar Year 2021 Annual Operations Report; Appendix B.27 F 28 The requirement that all aircraft operations at SMO need to stay at or below the 95 dBA SENEL measured at fixed noise monitor sites located 2,200 feet from either end of the runway (see Figure 13-7) is the result of an agreement between the City of Santa Monica (as the airport proprietor) and the FAA. As part of this agreement, the City is not required to report noise issues to the State, and does not provide noise reports to the Airport Commission.

The City states that “All violations of the Santa Monica Noise Code are subject to progressive sanctions of up to $10,000 dollars, including civil misdemeanor charges, and suspension or revocation of Airport privileges.”28F
29 The City’s recommended procedures are intended to help mitigate aircraft noise, but not interfere with federal aviation regulations, air traffic control (ATC) instructions, or pilot-in-command safety priorities, including weather avoidance.

28 https://www.santamonica.gov/media/Public%20Works/Airport/noise%20reports/2021%20Annual%20report.pdf, accessed July 2, 2025. 29 https://www.santamonica.gov/noise-mitigation-policy, accessed July 2, 2025. Refer to this webpage for information regarding specific aircraft that have been shown to not meet the maximum noise level of 95 dBA and are permanently excluded from operating at SMO after one violation and are subject to misdemeanor prosecution.

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Santa Monica also has a “Fly Neighborly Program” that includes the following set of voluntary procedures that help pilots avoid sensitive areas and reduce the impact of aircraft operations on the community:

Voluntary Night Arrival Curfew: Pilots are requested to avoid operations between 11 P.M. and 7 A.M. Monday through Friday, or until 8 A.M. on weekends. Although arrivals are permitted 24 hours a day, pilots are requested to comply with the airport’s voluntary night arrival curfew.

In an effort to improve compliance with the airport’s voluntary night arrival curfew, all operators that arrive during these hours are counseled by staff to comply with the arrival curfew in the future. Mandatory enforcement is disallowed by federal law.

Visual Flight Rules (VFR) Departure and Arrival Flight Paths: Aircraft departures to the west are requested to overfly the length of the Penmar Golf Course and initiate northerly turns at the shoreline, or southerly turns at Lincoln Boulevard. Departures to the east are requested to initiate crosswind turns over the 405 Freeway. SMO also requests that arriving aircraft using VFR follow certain flight patterns. Aircraft observed operating outside requested flight patterns are contacted and advised of the proper Noise Management procedures. Operators who deviate from noise management flight patterns due to weather, traffic or given a mandatory instruction from Air Traffic Control are not contacted by airport staff.

Auxiliary Power Unit (APU) Limitations: Many jet aircraft utilize APUs to provide electricity to aircraft systems prior to, or after a flight. Pilots are requested to limit APU use to thirty minutes.

Additionally, the APU is considered an engine start and shall comply with the Airport’s curfew restrictions.

Reverse Thrust Use: Due to the ground noise generated by aircraft utilizing reverse thrust upon landing, the Airport recommends minimum reverse thrust use except as necessary for safety, particularly during the nighttime hours.

IFR Engine Start Procedures: To minimize ground delays between engine-start and takeoff, fixed wing turbine aircraft shall obtain approval from Air Traffic Control prior to starting up engines.

Helicopter Arrival Procedures: The Letter of agreement between the City of Santa Monica and the FAA reflects the Airport Working Group’s recommendation to route helicopters approaching Santa Monica Airport from the north or south at or above 900 feet elevation, and approach to land perpendicular to the runway heading.

VULNERABILITY AND RISK ASSESSMENT
Ground and Airspace Safety
Although there are a variety of systems and procedures in place to mitigate aviation hazards, including air traffic control systems and operational safety requirements for pilots, accidents due to equipment failures or pilot error do happen. A substantial majority of general aviation accidents occur on or adjacent to the runway, and national data indicate that about three-fourths of all general aviation landing accidents occur during touchdown or roll-out (usually hard or long landings, ground loops, etc.). These types of accidents seldom (less than 11% of the time) result in serious or Local Hazard Mitigation Plan Section 13
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fatal injuries.29F
30 The remaining about one-quarter of general aviation landing accidents take place in the landing pattern, on final approach, or during a go-around attempt. A common circumstance that can result in an approach accident is pilot misjudgment of the aircraft descent rate and failure to add power soon enough to keep the aircraft in the air. Poor visibility, unexpected downdrafts, or tall objects beneath the final approach course can intensify this problem. Another prospective type of landing accident can occur if a pilot overshoots a turn from base to final and inappropriately cross controls the airplane rudder and ailerons while attempting to return to the runway alignment. The result can be a stall, spin, and uncontrolled crash.

As discussed previously and summarized on Table 13-3, incidents and accidents involving aircraft taking off or landing at SMO that have occurred since the early 1960s have been documented, with the data indicating that these accidents and incidents constitute a very small percentage of overall airport operations. Similar to the national data, most of the incidents and accidents reported for SMO-related aircraft occurred during takeoff or landing, and on the runway or within a short radius of the airport. Although not quantified separately, a fairly large percentage of the incidents at SMO appear to be related to pilot training, although most of these have been non-fatal.

Small airplane accidents, although far less catastrophic than accidents involving large commercial aircraft carrying dozens if not hundreds of passengers, can still pose a wide range of impacts to both the passengers and bystanders on the ground. Small aircraft accidents can result in injuries and fatalities. The injuries can be both physical and psychological. Property damage may include partial or complete destruction of the aircraft itself, and debris from the crash can damage buildings, vehicles, and other infrastructure. Even if the aircraft does not impact a building, spilled fuel and other substances, such as hydraulic fluid, can contaminate the ground or the water near the impact location. The spilled fuel can ignite, causing fires and explosions that could impact the victims and others near the impact site. In fact, post-crash (or post-impact) fires (PIFs) are often the cause of injuries and deaths in accidents that would have otherwise been survivable.30F 31 Economic costs
associated with aircraft accidents include financial losses related to the damaged aircraft and damaged property; losses associated with medical expenses, insurance claims, and legal fees; emergency response and environmental cleanup expenses; and in some cases, even evacuation and sheltering costs for impacted residents on the ground.

Given these concerns and findings that show that most aircraft accidents occur at or very near the airport, airport land use compatibility plans have traditionally emphasized the identification and establishment of airport safety compatibility zones, or airport influence zones (AIZs). The overall objective of these zones is to minimize risks associated with aircraft flights and other operational accidents, and reduce the impacts of aircraft-related noise (discussed further in the next section).

There are two components to this strategy: 1) safety of people and property on the ground, and 2) the protection of navigable airspace from hazardous obstructions to ensure the safety of aircraft occupants.

30 Based on national data from the NTSB for the years 1990-2000 presented in Caltrans Division of Aeronautics, 2011, California Airport Land Use Planning Handbook, Appendix E. 31 Based on https://skybrary.aero/articles/light-aircraft-post-crash-fires, accessed July 3, 2025.

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The AIZ31F
32 for SMO, as defined by the ALUC and shown on Figure 13-5, includes only the airport property proper and the off-airport runway protection zones (RPZs). The airport property includes the runway itself and the inner approach/departure zone, which refers to the area immediately adjacent to the runway from where aircraft are either taking off or landing. These are a few of the tiers or areas around airports where potentially conflicting land use patterns and intensities are described in federal and/or state and local regulations. Specifically, both the FAA and Caltrans Division of Aeronautics establish flight path and adjacent use regulations to prevent obstructions from being constructed in the airport’s navigable air space. The safety emphasis is on the runway surface and the areas immediately adjoining it. Standards are established that specify ground surface gradients for areas adjacent to runways and the acceptable location and height of aeronautical equipment placed nearby. These areas normally, but not always, are encompassed within the airport boundaries. Residences are not to be located within the inner approach/departure zone, whereas other urban uses are provisionally permitted based on use and population density. FAA authority, however, only applies to airport lands and not to surrounding lands, which are within the jurisdiction of the County ALUC and the City.

Ideally, RPZs and other inner safety zones should be entirely free of objects, with compatible land uses within RPZs typically including agricultural lands, golf courses, and other similar uses, and do not include buildings, as these zones are meant to provide a clear area for aircraft to overrun, undershoot, or veer off the runway. The California Division of Aeronautics strongly recommends that churches, schools, hospitals, office buildings, shopping centers, and other places of public assembly, as well as fuel storage facilities, be prohibited from the RPZ. Automobile parking is considered acceptable only on the outer edges of RPZs (outside the extended object free area).

However, given the highly urbanized environment, this is not the case at SMO. In fact, the airport’s surrounding land use pattern is diverse and has evolved away from the historically predominant aviation-based activities to a broad mix of other, often incompatible uses, including residential, commercial, offices, arts-based businesses, industrial research and development, and institutional (education) (see Plate 13-2), with single-family development predominating within and near the inner safety zones and the RPZs. The neighborhoods within these zones are most affected by aircraft operation hazards, and noise and air emissions. The only compatible land uses near the airport, within the airport influence zone, are the Penmar Golf Course on the west-southwest, which has been used in a few instances as a landing location by small aircraft in distress, and Clover Park. The ALUC’s ALUP does establish procedures for determining if planning efforts or substantial changes to zoning and building ordinances are consistent with the ALUP. During SMO’s remaining operational life, the FAA and the County ALUC will continue to review land use proposals within the airport area of influence, will provide guidance to the City, and may object to certain land use proposals.

Aviation Noise
Noise associated with airport operations and from aircraft overflights is one of the essential considerations of airport land use compatibility programs. The traditional, basic strategy for achieving noise compatibility within an airport’s vicinity has been to limit development of land uses that are particularly sensitive to noise. Thus, the most acceptable land uses for areas exposed to

32 The airport influence area, or zone, is defined as the geographic boundary of the ALUCP. The ALUC establishes the boundary of this zone based on the location and configuration of the airport, and the extent of the noise and safety impacts associated with that airport (Caltrans Handbook, 2011).

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significant levels of aircraft noise have been ones that involve few people (such as farmland or open spaces), or those that generate significant noise levels themselves (such as industrial uses). As discussed above, these are not the land uses common in the immediate vicinity of SMO.

Many people can be sensitive to aircraft noise even if it is barely audible above the quiet, ambient noise level, with about 25% of the population reporting annoyance when outdoor noise levels exceed about 55 dBA (see Figure 13-6). In fact, there is “abundance evidence that aircraft noise exposure in the vicinity of airports is related to annoyance, and some evidence that annoyance response has increased in recent years.”32F
33 Moreover, and significantly, outdoor aircraft noise levels exceeding 60 dBA during the day and 45 dBA at night have been associated with an increased incidence of hypertension, and exposure to outside noise levels at about 50 dBA have been associated with learning difficulties in schoolchildren.33F 34 Other studies have documented an
association between noise and high-blood pressure, stroke, heart attacks, hearing loss, sleep disruption, speech interference, cognitive performance, and depression, among other conditions.34F 35 The data reported above, which apply to areas near commercial airports and not general aviation airports like SMO, are remarkable considering that, according to the FAA, between 1975 and 2023, the number of U.S. residents exposed to significant levels of aircraft noise has fallen by about 94%, even though the number of enplanements35F
36 has increased by 365%. For the period between 2000
and 2023, these numbers are 55% reduction in noise exposure and 33% increase in enplanements. 36F 37 The decrease in noise exposure is attributed primarily to the adoption of quieter aircraft and advancements in noise reduction technology. Specifically, advances in piston-driven aircraft engines and jet engine technology have improved aircraft performance capabilities and reduced noise emitted by aircraft engines. At the same time, advances in noise reduction technologies for buildings have been developed and are applied for new construction or redevelopments in areas susceptible to transportation noise. These advances include soundproofing roofing and ceiling materials, double- or triple-pane windows, acoustic seals and sealants, soundproof doors, and building noise barriers that block or deflect noise from aircraft. Some airports have adopted voluntary programs funded primarily by the FAA that address aircraft noise issues whereby homes and/or schools within the airport-generated 65 dBA or greater noise contour are considered potentially eligible for sound insulation upgrades using a variety of the sound-proofing treatments listed above. In some cases, airports have bought the impacted homes and either converted them into non-residential uses, or replaced them with better insulated homes that are then placed back in the market.

The management and mitigation of aircraft noise on surrounding neighborhoods are dependent on the measurement and monitoring of airport-related noise. To do this, airports use noise monitoring systems that rely on a network of sensors that collect data on aircraft noise levels, flight paths, and other relevant data to identify noise sources, assess the exposure levels that airport-adjacent neighborhoods are being exposed to, and determine what noise abatement procedures, if any, are needed. SMO was one of the first airports to install a permanent noise monitoring system, and

33 Basner, M., Clark, C., Hansell, A., Hileman, J.I., Janssen, S., Shepherd, K., and Sparrow, V., 2017, Aviation noise impacts: State of the science: Noise Health, Vol. 19, No. 87, pp. 41-50, doi:10.4103/nah.NAH_104_16. 34 Kaltenbach, M., Maschke, C., and Klinke, R., 2008, Health consequences of aircraft noise: Deutsches Ärzteblatt International, Vol. 105, No. 31-31, pp. 548-556, doi: 10.3238/arztebl.2008.0548. 35 Faiyetole, A.D., Sivowaku, J.T., 2021, The effects of aircraft noise on psychosocial health: Journal of Transport and Health, Vol. 22, paper 101230; doi:10.1016/j.jth.2021.101230. 36 Defined as the number of passengers boarding flights at a particular airport. 37 https://www.airlines.org/dataset/aircraft-noise-exposure-u-s/, accessed July 7, 2025.

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currently conducts noise monitoring and noise modeling using data collected with the airport’s permanent Noise and Operations Monitoring System (NOMS). This system relies on six Noise Monitoring Terminals (NMTs) on the ground to collect the CNEL data needed for the analyses; two of these are located east of the airport, and four are located west of the airport. The data are processed using a software system developed by the FAA (FAA’s AEDT Version 3f software) that “models aircraft performance in space and time to estimate fuel consumption, emissions, noise, and air quality consequences.”37F
38 As discussed previously, SMO’s approach is to regulate and limit Single-Event Noise Exposure Levels (SENELs) to less than 95 dBA (see Figure 13-7), and Community Noise Equivalent Levels (CNELs)38F
39 to less than 65 dB, the standard issued by federal, state and local authorities. CNEL noise levels measured at the six SMO NMTs during 2023 range between 52.1 and

59.5 dB.39F
40 The data are also used to generate airport noise contours for the airport. Airport noise contours for SMO in 201940F
41 are illustrated on Figure 13-8. The figure shows that CNELs at or above the regulated 65 dB were measured only within airport property, along the runway, and did not extend into the residential areas to the east and west of SMO. Annual 2023 CNEL contours show a similar pattern as the 2019 contours, also limited to the airport property, and centered along the runway. The main differences between the 2023 and 2019 contours are that in 2023 the 70 dB contour is shorter and does not bulge to the north and south of the runway, and that in 2023 SMO-generated CNELs did not reach 75 dBs.41F
42 38 https://www.santamonica.gov/media/Public%20Works/Airport/noise%20reports/Calendar%20Year% 202023%20CNEL%20Noise%20Contours%20Report.pdf, accessed July 7, 2025. 39 Both SENEL and CNEL are noise measurement metrics, but SENEL measures the noise exposure from a single event, like an airplane flyover, and is not averaged over time, whereas CNEL is a cumulative noise level averaged over time, typically a year, that accounts for the time of day when a noise occurs, with evening and nighttime noises weighted more than daytime measurements. 40 Ibid, based on Table 3-1 in the above-referenced report. 41 Based on data from the County of Los Angeles Open Data Portal, Airport Noise Contours, updated in 2019. These are the data presented in the City’s 2025 Safety Element of the General Plan. 42 For additional information regarding the 2023 data refer to https://www.santamonica.gov/media/Public%20Works/Airport/noise%20reports/Calendar%20Year%202023%20 CNEL%20Noise%20Contours%20Report.pdf, and Figure 3-9 therein.

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Figure 13-8: Noise Contours for SMO
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To further manage and address the noise concerns of residents living near the airport, Santa Monica has instituted the Santa Monica Fly Neighborly Program42F 43, one of the elements in the City’s Airport
Noise Management Program.43F
44 This program is designed to help pilots avoid sensitive areas and reduce the impact of aircraft operations to the greatest degree practicable. The Airport Noise Management Program explains basic noise concepts and noise programs at the airport, allows residents to research flight operations, provides methods for filing noise complaints and facilitates contact with the Noise Operations Office. Complaints received as a result of SMO operations are listed in Table 13-4 for the years 2018 through 2023. In 2022 and 2023, the City received an average of 409 complaints per year, which is two to nearly 3.5 times less than in the previous four years.

Moreover, 110 less complaints were received in 2023 compared to 2022. Airport staff investigate all aircraft-related reports by neighbors and follow through as appropriate, including contacting aircraft operators that deviated from the requested flight paths, to educate them about proper noise management procedures. Airport staff also counsel aircraft operators that exceeded or nearly exceeded the maximum noise level of 95 dBA SENEL, and if those operators do not comply and log several additional violations, they are either fined, or, after multiple violations, are excluded from operating at SMO.

Table 13-4: Noise Complaints Related to SMO Operations, 2018-202344F 45 Year Total Number of Operations Total Number of Noise Complaints 2018 72,061 1,413
2019 77,038 855
2020 58,228 1,127
2021 67,986 1,454
2022 72,039 464
2023 57,110 354
Potential for Hazardous Materials Related to Historical Airport Land Uses As discussed in the Airport History section above, before the establishment of the airport in the early 1920s, the area was used as farmland. In the 1930s and 1940s, the airport and the lands immediately surrounding the airport housed the Douglas Aircraft manufacturing facility, except during WWII, when the airport was leased and operated by the Federal government. These industrial and military uses involved the use of a variety of chemicals that if released into the environment, likely resulted in the contamination of soil and/or groundwater. While some chemicals such as ammonia and acetone have a relatively short lifespan in the atmosphere and soil, other compounds are long-lived and can persist for decades in the environment.

Given the airport’s history, residual contamination is likely to be present beneath the ground surface of the airport property. Since the 1990s, the City has been conducting or requiring site investigations

43 City of Santa Monica web site “Airport Noise Management” available at https://www.santamonica.gov/topicexplainers/airport-noise-management. 44 https://www.santamonica.gov/topic-explainers/airport-noise-management 45 Based on data extracted from https://public.tableau.com/app/profile/sm.airport/viz/SMO_Noise_Dashboard_Tableau_Master_16551529204300/ AIRCRAFTOPERATIONSDASHBOARD, accessed on April 21, 2023, and https://www.santamonica.gov/media/Public%20Works/Airport/noise%20reports/Calendar%20Year%202023%20 Anuual%20Operations%20Report.pdf, accessed on July 7, 2025.

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to determine the presence and level of potential subsurface contamination at sites at and near the airport. Past assessments at nearby properties have already indicated groundwater and soil contamination. Two of these sites are described further below. • The Santa Monica Business Park property at 3000 Ocean Park Boulevard was a part of the former aircraft manufacturing facility owned and operated by Douglas Aircraft Corporation between 1928 and 1975. Other properties that used to be part of the aircraft manufacturing facility include Clover Park, the small residential neighborhood between Centinela Avenue South and Bundy Drive, and the SMO site itself.

Volatile organic compounds (VOCs) have been identified as chemicals of potential concern in the soil, soil vapor, and isolated perched groundwater zones to depths exceeding 70 feet below the ground surface under the Business Park and in the vicinity. The VOCs that have been identified consist primarily of trichloroethene (TCE), 1,1-dichloroethene (1,1-DCE), and 1,1,2-trichloro-1,2,2-trifluoroethane (Freon 113). For the past nearly 25 years, at the direction of The Boeing Company, various studies have been conducted to assess the lateral and vertical extent of the contamination, with soil vapor extraction systems being used to remediate the VOC-contaminated soil vapor and groundwater. Other ongoing environmental activities at the site include indoor air monitoring and groundwater monitoring and testing, with groundwater samples collected from the monitoring wells routinely analyzed for VOCs and 1.4-dioxane.45F
46 • The Bundy Campus of Santa Monica College is contiguous to the southeast boundary of the SMO property, at 3171 Bundy Drive in Los Angeles (Figure 13-2). The campus site was previously used for aviation manufacturing uses, which resulted in the contamination of soils and groundwater with solvents and non-petroleum hydrocarbons. This site was remediated in the late 1990s and early 2000s, involving the excavation of impacted soil, removal of free product, and in-situ physical or chemical treatment of contaminated groundwater. Site closure status was issued by the Los Angeles Regional Water Quality Board in 2005.46F 47 Given these findings, additional contamination could be encountered below the airport property.

Environmental studies to assess the presence, impact, and extent of various contaminants will be necessary before the property can be considered for re-development. Based on the findings, mitigation may likely be required, depending on the type of development proposed. Some of the older buildings still on airport property may also have asbestos and/or lead paint that will require special handling if the buildings are demolished or are renovated.

Another environmental concern associated with both past and present airport operations is lead contamination of the air and soil due to the use of leaded fuel to power aircraft engines. In 2022, the U.S. Environmental Protection Agency (EPA) published an “endangerment finding” indicating

46 Based on data from JHA Environmental, 2025, Semi-Annual Remediation Status, Report No. 55m Second Half of 2024, The Boeing Company, Former Douglas Aircraft Company Plant A, Santa Monica, California 90405, available from https://documents.geotracker.waterboards.ca.gov/esi/uploads/geo_report/9938540935/ SLT4307472.PDF, and Los Angeles Regional Water Quality Control Board, 2025, Approval of 2025-2026 Groundwater Monitoring Plan, available from https://documents.geotracker.waterboards.ca.gov/regulators/ deliverable_documents/8820996940/0130B_Boeing%20SM_Approval%20of%202025%202026%20GW%20Mo n%20WP_03_12_2025.pdf, both accessed July 8, 2025. 47 Based on data extracted from https://geotracker.waterboards.ca.gov/profile_report.asp?global_id=T0603701426, accessed July 8, 2025.

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that emissions from aircraft operating on leaded fuel “cause or contribute to air pollution which may reasonably be anticipated to endanger public health or welfare.”47F 48 As part of this announcement,
the EPA indicated that aircraft using leaded fuel are the dominant source of lead emissions into the air, with the majority of the aircraft using leaded aviation gasoline being small, piston-engine airplanes that typically carry a small number of passengers.

In 2023, researchers published a multi-year study that involved the analysis of over 14,000 lead blood samples from children 5 years old and younger living near the Reid-Hillview Airport in Santa Clara County, California, a general aviation airport that services piston-engine aircraft using leadformulated aviation gasoline. The researchers found that blood lead levels were higher in children that lived closest to the airport, and especially in those living downwind of the airport. Blood lead levels were also found to directly correlate with the volume of piston-engine aircraft, a finding that they were able to make because reduced airport operations instituted during the Covid pandemic provided useful data that they could compare to other years with higher number of operations.48F 49 In support of the national effort to reduce lead emissions from piston-engine aircraft, Santa Monica began transitioning aircraft fueling at SMO from leaded to unleaded aviation fuels in or around 2017, and on March 28, 2022, Santa Monica successfully transitioned the SMO self-serve fuel station located at the southwest corner of the airfield to unleaded aviation gasoline (UL94, a 94- octane unleaded aviation). Since then, 100% of flight schools and almost all tenants have transitioned their compatible aircraft to the new unleaded fuel. In December 2024, SMO began to offer Swift Fuels 100R unleaded aviation49F
50 gasoline available for purchase at the airport’s self-service station, making SMO the first U.S. airport to offer that fuel for retail purchase. To encourage operators to make the switch to unleaded aviation gas, SMO offsets the added cost of the unleaded fuel over 100LL fuel, and provides other incentives.

Social Vulnerability to Airport Hazards
Like most other hazards discussed in this Plan, airport-related hazards have a disproportionate impact on health-sensitive populations including young children, seniors, people with asthma or other respiratory concerns and heart conditions, and low-income residents. However, a study that looked at sociodemographic characteristics of communities adjacent to 90 airports throughout the United States found that there is “substantial heterogeneity across airports,” with the only characteristics that were statistically significant across the cohort investigated being race/ethnicity and education levels. Specifically, the study found that communities with a higher percentage of Hispanics, and residents with only a high-school education, regardless of race/ethnicity, had a higher probability of being exposed to aircraft noise.50F 51 Review of the Social Vulnerability Index (SVI) data on a census-tract basis based on 2022 demographics collected and analyzed by the Centers for Disease Control and Prevention and the

48 https://www.epa.gov/newsreleases/epa-proposes-endangerment-finding-lead-emissions-aircraft-engines-operateleaded-fuel, a report dated October 7, 2022 that was accessed most recently on July 8, 2025. 49 Zahran, S., Keyes. C., and Lanphear, B., Leaded aviation gasoline exposure risk and child blood lead levels:

PNAS Nexus, Jan. 10 2023 edition, Vol. 2, Issue 1, doi:10.1093/pnasnexus/pgac285. 50 https://nbaa.org/aircraft-operations/airports/smo/availability-of-100r-lead-free-avgas-caps-year-of-positivedevelopments-for-smo/, accessed July 3-8, 2025. 51 Simon, M.C., Hart, J.E., Levy, J.I., VoPham, T., Malwitz, A., Nguyen, D., Bozigar, M., Cupples, L.A., James, P., Laden, Fr., and Peters, J.L., 2022, Sociodemographic patterns of exposure to civil aircraft noise in the United States: Environmental Health Perspectives, Vol. 130, Issue 2, doi:10.1289/EHP9307.

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Agency for Toxic Control Substances and Disease Registry51F 52 show that most of the census tracts that
include the SMO’s influence area have a low overall SVI (Figure 13-9). This means that these census tracts do not have a high percentage of demographic and socioeconomic factors such as poverty, crowded housing, high percentage of households with residents aged 65 or older, or aged 17 and younger, with no high-school diploma or health insurance, which are factors known to adversely impact a community’s ability to respond and recover from natural or human-caused disasters. Note that the census tracts that include the airport itself (census tract 702300) and the airport’s area of influence (census tracts 7271300 to the east, in Los Angeles, and census tracts 702202 and 7273100, around the Penmar Golf Course) all have low social vulnerability indices. The Los Angeles census tract to the southeast of SMO (7271500) has a low to medium SVI. All these census tracts do house schools and child care centers, and a few house nursing homes.

Figure 13-9: Social Vulnerability of Census Tracts Near the Santa Monica Airport (showing nursing homes, schools, and child care centers)

52 https://www.atsdr.cdc.gov/place-health/php/svi/ accessed July 8, 2025.

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AIRPORT HAZARDS MITIGATION ACTIVITIES
The management of airport-related hazards must address not only on-airport issues but potential safety hazards that can affect off-airport uses and populations. Because the region around SMO is extensively developed with non-airport compliant land uses, off-airport mitigation activities for this airport should emphasize the management of aircraft-related noise and vibrations, reduction or elimination of harmful air emissions from aircraft that could impact adjacent neighborhoods, and the implementation of various practices designed to reduce aircraft accidents.

As discussed in the previous sections, SMO is one of a handful of airports in the United States that has mandatory noise restrictions such as maximum noise limit and curfew hours, and also has a strict voluntary Airport Noise Management Program that strongly encourages pilots to follow designated flight paths designed to avoid sensitive areas, employ noise abatement departure procedures that reduce noise levels near the airport, and conduct their operations during airport business hours, typically between 7 A.M. and 11 P.M during the week and until 8 A.M. on weekends. Additional specifics of Santa Monica’s “Fly Neighborly Program” are provided in the Regulatory Setting section of this report, under Aviation Noise. At the same time, the airport provides several resources that allow residents and interested parties to research flight operations and file airport-related noise questions or complaints, with airport staff dedicated to responding to these concerns. As part of this program, the airport publishes monthly and annual reports documenting the noise levels recorded, number of aircraft noise complaints and inquiries, curfew violations, aircraft path deviations, and other data.

Additional reductions in aircraft-generated noise can be anticipated if and when electric planes become more prevalent, as electric planes are quieter than traditional gas-powered aircraft. SMO is already home to a few new electric flight-training aircraft.52F 53 Also as discussed above, SMO is a leader in taking steps to minimize leaded fuel use by offering non-leaded aviation gas available for retail purchase onsite. As more of the aircraft operators flying out of SMO use these non-leaded gasoline alternatives, lead emissions into the air above the airportadjacent neighborhoods are expected to decrease, potentially at significant levels. Continuation of this program is strongly encouraged.

On-airport and near-airport hazards related to accidents or incidents involving aircraft flying into or out of SMO can potentially be reduced through a combination of improvements to airport and airport traffic infrastructure, and continued monitoring and possibly oversight of equipment safety procedures that are the pilot’s responsibility. In 2024, the City of Santa Monica “completed a major airfield project that included replacement of the ailing airfield lighting infrastructure, restoration of airfield markings and runway pavement rehabilitation.” Additional improvements that are being worked on as of the writing of this report include “a new pilot-controlled lighting system and continued pavement rehabilitation on airport ramps and taxiways.”53F 54 All of these improvements
should increase safety and efficiency at the airport.

53 https://nbaa.org/aircraft-operations/airports/smo/availability-of-100r-lead-free-avgas-caps-year-of-positivedevelopments-for-smo/, accessed July 8, 2025. 54 Ibid.

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At the national level, the FAA has been working on modernizing the National Airspace System (NAS) through its Next Generation Air Transportation System (NextGen).54F 55 This program aims to improve
air traffic control infrastructure, including communications, navigation, surveillance, automation, and information management systems, for the purposes of increasing “the safety, efficiency, capacity, predictability, flexibility, and resiliency of U.S. aviation.” To accomplish these goals, the FAA has implemented new air traffic technologies and procedures, such as satellite-enabled surveillance of aircraft location information that helps air traffic controllers keep track of aircraft.

Other safety and security enhancements that have been implemented or are in the process of being implemented include “state-of-the-art automation systems that support air traffic controllers” to manage and keep track of individual aircraft, especially in congested airspace such as that in southern California. These systems also help to define efficient, arrival (optimized profile descent) and departure (optimized climb profile) flight routes for individual aircraft that help reduce aircraft noise, improve aircraft fuel usage efficiency, and reduce air emissions. The NextGen Southern California Metroplex effort that includes SMO, LAX, and many other southern California airports, was completed in the summer of 2018.55F
56 Finally, at the individual level, pilots should be encouraged to execute thorough, methodical and regular inspections of their aircraft before they take off, and heed any notifications from aircraft manufacturers when a mechanical issue common to a given line of airplanes is recognized, prompting a recall or modification. Airport staff could keep a listing of these recall notices and require pilots to provide evidence that they have undertaken the required improvements to their planes as appropriate.

AIRPORT HAZARDS RESOURCE DIRECTORY
City Resources
City of Santa Monica Public Works Department – Airport Division 3223 Donald Douglas Loop South, Santa Monica, CA 90405
(310) 458-8591
https://www.santamonica.gov/places/city-facilities/santa-monica-airport-smo https://www.santamonica.gov/departments/public-works
Santa Monica Airport Commission
The Commission acts in an advisory capacity to the City Council on matters pertaining to the administration of SMO and other aviation matters affecting the City. The commission meets on the 4th Monday of every month, except in August and December, at 7:00 PM in the Council Chambers. 1685 Main Street – City Council Chambers
Santa Monica, CA 90401
https://www.santamonica.gov/events/airport-commission

55 https://www.faa.gov/nextgen, accessed July 3-9, 2025. 56 https://www.faa.gov/air_traffic/community_engagement/socal, accessed July 9, 2025. This website provides several links to YouTube video presentations that describe the Southern California Metroplex system.

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City of Santa Monica Community Development Department
1685 Main Street, Santa Monica, California 92660
(310) 458-2275
https://www.santamonica.gov/departments/community-development City of Santa Monica Fire Department
333 Olympic Drive, Santa Monica, CA 90401
(310) 458-8652 or 911 for emergencies
Santa Monica Office of Emergency Management
333 Olympic Drive, Santa Monica, CA 90401
(310) 458-2263
Email: [email protected]
County Resources
Los Angeles County Airport Land Use Commission (ALUC)
Los Angeles County Department of Regional Planning
320 West Temple Street, Los Angeles, CA 90012
(213) 974-6409
https://planning.lacounty.gov/public-hearings-and-meetings/airport-land-use-commission/ https://planning.lacounty.gov/airport-land-use-planning/ Los Angeles County Fire Department
(323).881-2411
https://fire.lacounty.gov/
Los Angeles Regional Quality Control Board
320 4th Street, Suite 200 , Los Angeles, CA 90013
(213) 576-6600
https://www.waterboards.ca.gov/losangeles/
State Resources
California Department of Transportation (Caltrans) Division of Aeronautics California Department of Transportation (Cal Trans) – District 7 100 South Main Street 10th Floor, Los Angeles, CA 90012 (213) 897-3656
https://dot.ca.gov/programs/aeronautics/airport-land-use-planning Governor’s Office of Emergency Services (Cal OES)
https://www.caloes.ca.gov/
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Federal Resources and Programs
Federal Aviation Administration
800 Independence Avenue, SW, Washington, DC 20591
(866) 835.5322 (866-TELL-FAA)
https://www.faa.gov/
https://www.faa.gov/regulations_policies/faa_regulations https://www.faa.gov/air_traffic/community_engagement/socal U.S. Department of Transportation
1200 New Jersey Ave, SE, Washington, DC 20590
(202) 366-4000
https://www.transportation.gov/aviation
National Transportation Safety Board (NTSB)
490 L'Enfant Plaza, SW, Washington, DC 20594
https://www.ntsb.gov/Pages/home.aspx
U.S. Department of Housing and Urban Development
For information regarding developments incompatible with airports and airfields. 451 7th Street, S.W., Washington, DC 20410
(202) 402-3815
https://www.hudexchange.info/programs/environmental-review/airport-hazards/ United States Coast Guard
U.S. Department of Homeland Security, Pacific Southwest District 11 https://www.uscg.mil/
Eleventh District Command Center Number: (800) 246-7236 - For maritime emergency use National Oceanic and Atmospheric Administration
National Weather Service
San Diego Weather Forecast Office
11440 W. Bernardo Court, Suite 230, San Diego, CA 92127 (858) 675-8700
https://www.weather.gov/sgx/
Environmental Protection Agency (EPA)
https://www.epa.gov/environmental-topics/air-topics
https://www.epa.gov/aboutepa/epa-region-9-pacific-southwest Publications
Refer to the footnotes of this document for a variety of publications that address airport safety regulations and airport safety hazards in general and specific to the Santa Monica Airport.