2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 66 are expected to remain a recurring threat throughout Southern California. Continued fuel management, defensible space maintenance, wildfire preparedness programs, and implementation of wildfire mitigation projects will be important for reducing future risk within the City.
Climate Change Considerations
Climate projections for Southern California indicate increasing temperatures, more frequent extreme heat events, and greater variability between wet and dry years. These conditions may contribute to longer fire seasons, drier vegetation, and increased wildfire intensity.
Climate change is expected to increase temperatures and lead to more frequent and prolonged droughts throughout Southern California. These conditions are anticipated to increase vegetation dryness and fuel loading, contributing to elevated wildfire risk. In the foothill and mountainous areas surrounding Rancho Cucamonga, climate change may increase wildfire frequency, fire intensity, and the number of acres burned annually.
Increased wildfire activity may also elevate the risk of smoke impacts, post-fire erosion, and debris flows affecting the City.11
11 Cal Adapt Climate Tool
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 67 HAZARD PROFILE: FLOOD
Description
Flooding
Floods are a common hazard in many parts of California, including Rancho Cucamonga.
Ultimately, a flood occurs when there is too much water on the ground for local water bodies to hold, causing water to accumulate in naturally dry areas. They are often caused by heavy rainfall, though floods can also occur after a long period of moderate rainfall or if unusually warm weather causes mountain snow to melt faster than expected. Floods that develop quickly, known as flash floods, are especially dangerous because there may be little warning that one is occurring, but floods can also build over a more extended period.
Floods are dangerous for several reasons. The floodwaters themselves can be deep enough for people to drown and move fast enough to sweep people away. Moving water can damage buildings with its force (in extreme cases, it may move entire structures) or carry large debris that damages objects it collides with. When water enters buildings, it can cause extensive damage to personal property, including building materials, furniture, electronics, and numerous other items. Both standing and moving water can be barriers to movement, isolating people and hindering evacuation, rescue, or relief efforts.
Dam Failure/Inundation
Dam failure can result from several causes, such as earthquakes, rapidly rising floodwaters, and structural design flaws. These events can occur instantaneously or very gradually, depending on the source of the failure. Inundation associated with these events can cause loss of life, damage property, and displace people residing along the inundation path. According to the California Division of Safety of Dams (DSOD), a dam falls under its jurisdiction if its height is greater than 6 feet and it impounds more than 50 acre-feet of water, or if its height is greater than 25 feet and it impounds 15 acre-feet of water.12 Based on these criteria, numerous dams throughout California fall under DSOD jurisdiction, including several facilities located within Rancho Cucamonga. 12 California Department of Water Resources. Jurisdictional Sized Dams. https://water.ca.gov/Programs/AllPrograms/Division-of-Safety-of-Dams/Jurisdictional-Sized-Dams
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 68 Location and Extent
Flooding
Flood events are measured by their likelihood of occurrence. For instance, a 100-year flood is a flood with a 1-in-100 (1.0 percent) chance of occurring in any given year. A 500-year flood is a flood with a 1-in-500 (0.2 percent) chance of occurring in any given year. The 100-year flood has been designated as the benchmark for major flood events.
Thus, 100-year floods are referred to as “base floods.” Floodplains are areas prone to flooding and often experience frequent inundation. While it is possible for areas outside of these designated floodplains to experience flooding, the most likely locations to experience future flooding are low-lying areas near bodies of water. FEMA is the federal agency responsible for designating which areas of the United States are classified as floodplains.
The three most common designations are:
1) Special Flood Hazard Area: The area within a 100-year floodplain. 2) Moderate Flood Hazard Area: The area outside of the 100-year floodplain but within the 500-year floodplain.
3) Minimum Flood Hazard Area: The area outside of the 500-year floodplain.
Within these three designations, FEMA has multiple floodplain categories for each unique environment. Table 3-10 shows these detailed floodplain categories.
FEMA flood mapping identifies portions of Rancho Cucamonga as Zone AE (1-percent annual chance flood hazard), Zone X500 (0.2-percent annual chance flood hazard), areas of reduced flood risk associated with flood-control infrastructure, and Zone X (minimal flood hazard).13 The locations of these flood hazard areas are shown on the FEMA Flood Hazard Zone Map in Figure 3-8. The data depicted is from the most recent National Flood Hazard Layer made available by FEMA and may not include revisions associated with recently completed Letters of Map Revision.
Although flooding hazards can affect multiple areas of Rancho Cucamonga, less than 10% of the City is located within a mapped 100-year flood hazard zone. Development within identified flood hazard areas must comply with applicable flood protection standards that reduce flood vulnerability and support the safe use and occupancy of structures.
13 FEMA. (2026). FEMA Flood Map Service Center: Search By Address. https://msc.fema.gov/portal/search?AddressQuery=Rancho%20Cucamonga%2C%20CA
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 69 TABLE 3-10. FEMA FLOODPLAIN CATEGORIES
Category Description
A Within a 100-year floodplain, but the water height of the 100-year flood is not known A1-30 or
AE Within a 100-year floodplain and the water height of the 100-year flood is known AO Within a 100-year floodplain, and the water height of the 100-year flood is between one and three feet but not specifically known
A99 Within a 100-year floodplain, protected by flood protection infrastructure such as dams or levees
AH Within a 100-year floodplain, and the water height of the 100-year flood is between one and three feet and is specifically known
AR Within a 100-year floodplain, protected by flood protection infrastructure that is not currently effective, but is being rebuilt to provide protection V Within a 100-year floodplain for coastal floods, but the water height of the flood is not known
V1-30 or
VE
Within a 100-year floodplain for coastal floods and the water height of the flood is known
VO Within a 100-year floodplain for shallow coastal floods with a height between one and three feet.
B Within a 500-year floodplain, or within a 100-year flood plain with a water height less than one foot (found on older maps)
C Outside of the 500-year floodplain (found on older maps) X Outside of the 500-year floodplain (found on newer maps) X500 Within a 500-year floodplain, or within a 100-year flood plain with a water height less than one foot (found on newer maps)
D Within an area with a potential and undetermined flood hazard M Within an area at risk of mudslides from a 100-year flood event N Within an area at risk of mudslides from a 500-year flood event P Within an area at risk of mudslides from a potential and undetermined flood event E Within an area at risk of erosion from a 100-year flood event Source: CFR (Code of Federal Regulations). 2016. Title 44 (Emergency Management and Assistance), Part 64 (Communities Eligible for the Sale of Insurance), Section 64.3 (Flood Insurance Maps).
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 70 Figure 3-8. FEMA Flood Hazard Zones
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 71 Dam Failure/Inundation
The City of Rancho Cucamonga has eight catch basins that can inundate areas of the City if they fail. The basins serve several purposes, with a primary function of slowing and controlling the flow of water. Without basins to capture these flows, the County’s flood control channels could be inundated to the point that they would be unable to function.14 Figure 3-9 identifies the inundation zones for the catch basins within the City, described in Table 3-11. Of these inundation areas, two can flood properties outside of the City—Cucamonga Creek and San Sevaine. Based on this mapping, the San Sevaine Basin generates the largest inundation area, which inundates a portion of the City and neighboring Fontana.
Figure 3-9 also identifies the locations of major debris and flood control basins within Rancho Cucamonga. These facilities play an important role in reducing flood and debris flow hazards originating from the San Gabriel Mountains and foothill drainages.
TABLE 3-11. RESERVOIR CAPACITY/DAM INUNDATION AREAS
Catch Basin Name Reservoir Capacity
Dam Inundation
Area
Alta Loma Basin #1 & #2 155 acre-feet 332.4 acres
Cucamonga Creek 355 acre-feet 353.3 acres*
Day Creek 140 acre-feet 122.9 acres
Deer Canyon 24 acre-feet 212.3 acres
Demens Creek Debris Basin 35 acre-feet 206.9 acres
Etiwanda Basin 283 acre-feet 119.9 acres
Hickory Basin 220 acre-feet 333.7 acres
San Sevaine Basin #5 2,765 acre-feet 2,982.7 acres*
* Inundation zones impact areas outside of the city limits.
Source: Dams Within Jurisdiction of the State of California, September 2019, California Department of Water Resources, Division of Safety of Dams.
14 The Rutherford Report, San Bernardino County.
http://www.sbcounty.gov/rutherford/report/issues/2012_may/floodcontrol.html
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 72 Figure 3-9. Dam Inundation Zones
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 73 Past Events
Flooding
Located at the base of the San Gabriel Mountains, Rancho Cucamonga has a long history of flooding and debris flow events (Table 3-12). Since the adoption of the previous LHMP update, the region has transitioned from prolonged drought to multiple intense atmospheric river storm events, resulting in localized urban flooding, debris-flow concerns, flood advisories, and hazardous roadway conditions. Although the City’s debris basin and channel systems generally performed effectively during these events, severe storms in 2024 and 2025 demonstrated the continued flood risk facing the community.
Although major flood-control improvements have substantially reduced flood risk within Rancho Cucamonga, historic flood events demonstrate the City's continued exposure to flooding, debris flows, and alluvial fan hazards associated with intense precipitation events and canyon drainage systems.
TABLE 3-12. HISTORIC FLOOD EVENTS IN RANCHO CUCAMONGA
Year Event Description Impact
2025* It rained the most in Southern California on
Christmas Eve, with Rancho Cucamonga
receiving 3.47 inches of rain. The last account
for rainy holidays was in 2020 for California.
The powerful Christmas storm that
struck Southern California caused
widespread disruption, resulting in
major travel hazards, flash flooding,
evacuations, and structural damage
across the region.
2024* Multiple atmospheric river systems affected
Southern California during winter 2024,
resulting in FEMA Disaster Declaration DR4769-CA.
Flooding, debris flows, roadway
impacts, and stormwater system stress
occurred throughout the region.
2023* Multiple atmospheric river storms affected
Southern California between January and
March 2023, producing periods of heavy
rainfall, localized flooding, debris flows,
roadway flooding, and impacts to
transportation infrastructure throughout San
Bernardino County.
Localized flooding, debris accumulation
in drainage facilities, roadway impacts,
and increased erosion concerns
highlighted the importance of
stormwater infrastructure maintenance
and flood preparedness.
2022* A series of winter storms impacted Southern
California during late 2021 and early 2022,
generating localized flooding and debris flow
concerns in foothill areas.
Minor flooding and drainage impacts
were reported throughout the region,
emphasizing ongoing flood risks
associated with intense precipitation
events.
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 74 TABLE 3-12. HISTORIC FLOOD EVENTS IN RANCHO CUCAMONGA Year Event Description Impact
1983 This storm caused classrooms to flood with
mud and water. Floodwaters ripped out asphalt
streets and flooded homes. The street damage
throughout the Cucamonga area was
extensive, with washouts and cave-ins
common.
The damage estimate for streets
exceeded $180,000 from the initial
hours of the storm.
1978 The storm deposited significant debris into the
newly constructed Cucamonga Channel,
severely damaging the concrete channel walls.
As debris was removed from the channel, it
became clear that entire sections would need
to be rebuilt. Flood flows from the storm
eroded the entire six-inch concrete wall,
exposing and damaging the rebar. Thousands
of feet of channel were in danger of total
collapse during the storm. Significant damage
occurred to Beryl Avenue near Banyan. All the
block retaining walls were washed out. Large
chunks of pavement from Hellman Avenue
were washed away by a large dam that
diverted floodwater into 15 homes on La Vine
Street.
The County Flood Control Director
estimated the storm caused $70 million
in damage. More than $2 million of the
damage was to local roads. It cost more
than $2.9 million to repair the channel. It
is estimated that if this storm had
occurred in 1981, it would have caused
$280 million in damage due to the
extensive development in the City at the
time.
1969 This flood was rated the eighth-largest storm in
the previous 100 years. No repairs were made
when builders digging for dirt damaged a flood
levee structure in the Cucamonga Spreading
Grounds, causing it to fail. The remaining
levees and check dams held back the four
million tons of debris from Cucamonga
Canyon. This debris was added to the million
and a half tons left by a previous storm (1966).
Marine helicopters picked up flood victims from
rooftops, while homeowners in the Dawn
Haven tract were evacuated by sheriff’s
deputies and fire personnel using ropes.
Three-foot-deep water smashed through
windows, flowed through homes, and picked
up cars that were never recovered.
Most of the $68 million in damage
resulted from a debris blockage in
Cucamonga Creek, causing water and
debris to jump out of the channel and
carve a new one. The creation of this
channel impacted homes along
Carnelian, destroying four in the
process.
1943 In a small storm in January 1943, Arrow
Highway (Route) was washed away at
Hellman.
Various small buildings, vineyards, and
citrus groves were washed out.
1938 The storm from February 28 - March 3, 1938,
was the sixth-largest storm of record and
double the size of the 1969 flood. While the
recently constructed flood control projects on
the major canyons minimized flood damage, it
was discovered that the Cucamonga and Deer
Creek Spreading Grounds were the only
functioning flood structures remaining in the
entire tri-county area.
Fifteen hundred acres of orchards &
vineyards were entirely washed away.
Severe post-burn debris flows and
flooding were reported in Etiwanda
Canyon, causing extensive damage.
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 75 TABLE 3-12. HISTORIC FLOOD EVENTS IN RANCHO CUCAMONGA Year Event Description Impact
1934 Two floods hit the Rancho Cucamonga area in
1934, caused by two cloudbursts. Four inches
of rain fell in just a few hours.
Boulders washed across the highways.
Schools closed, and train service was
halted.
1916 In 1916, Cucamonga Creek began flooding
down the west side of Red Hill into Upland.
Twenty-one structures on the Deer debris cone
were washed away during this series of
storms.
Turner Avenue was a canyon 10 to 30
feet deep; 1,000 feet of recently paved
roadway on Archibald was washed out.
A subsequent storm caused the Day &
Deer Creek channel to shift west,
cutting a deep 30-foot gully and
destroying valuable farmland.
1891 In 1891, a great storm coincided with a rapidly
melting snowpack, but because so few
inhabitants were present, the damage was
limited. The damage would be repeated in
1910 and 1911 as all the tracks were washed
out by Cucamonga, Deer, and Day Creeks.
Again in 1914, the railroads were hard hit.
Hellman was entirely washed out to a depth of
8 feet.
The main damage was to the railroads
from flows from Deer Creek. The “rail
barons” pressed Congress to build a
dam at the canyon mouth. The 500-ton
boulders carried down by the flood flows
persuaded the railroads’ engineers that
a dam was impractical.”
1884 In 1884, severe flooding stranded travelers
when twenty-foot walls of water came roaring
out of the canyons.
Construction activities on the railroads
were disrupted.
1862 The largest storm of record occurred in 1862.
This storm was seven times larger than the
1969 Storm. It rained steadily for 28 days. Lytle
Creek cut a new permanent channel toward
San Bernardino, making it unlikely that
Cucamonga will flood again.
There was little damage reported
because there were only two ranches in
the area.
Source: City of Rancho Cucamonga Local Hazard Mitigation Plan (2013); San Bernardino County Flood Control District historical flood records; National Weather Service storm event records; FEMA disaster information; and City of Rancho Cucamonga records.
*Flooding events during the previous Plan Period
Dam Failure/Inundation
Rancho Cucamonga has not experienced a documented failure of a major flood-control basin or dam. However, historical flood events throughout the region demonstrate the importance of flood-control infrastructure in reducing flood and debris-flow hazards associated with canyon drainages and intense storm events.
Despite some significant flooding events in the late 1800s and early 1900s, including one in 1862 that wiped out the tiny Santa Ana River hamlet of Agua Mansa near presentday Colton, regional flood management and mitigation in San Bernardino County received little consideration until the Great Flood of March 1938. That deluge claimed
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 76 14 lives, left hundreds homeless, and caused an estimated $12 million ($220 million in 2020) in property damage.
In 1939, the State Legislature passed the San Bernardino County Flood District Act, which empowered the County to begin developing regional flood protection facilities to protect life and property. Today, San Bernardino County Flood Control operates and maintains 14 dams, 119 basins, 82 levees, and more than 250 miles of flood control channels. The dams, levees, and channels are designed to safely convey runoff around homes and businesses in the valley.15
Risk of Future Events
Flooding
There is no indication that severe rainfall events capable of causing flooding will abate in the future, either in Rancho Cucamonga or throughout Southern California. While the City may experience prolonged periods of drought or above-average precipitation, flooding will remain a recurring hazard. For areas within the 100-year and 500-year flood hazard zones, the annual likelihood of flooding is approximately 1 percent and 0.2 percent, respectively.
Because Rancho Cucamonga remains vulnerable to flooding during significant storm events, the City participates in the FEMA National Flood Insurance Program (NFIP).
Through the NFIP, Special Flood Hazard Areas are identified and mapped on Flood Insurance Rate Maps (FIRMs), which help guide floodplain management and flood insurance requirements. In addition to NFIP participation, the City has adopted local flood protection standards intended to reduce flood vulnerability, including minimum building elevations, floodproofing requirements, and structural anchoring requirements in flood-prone areas.
Since incorporation, the City has worked closely with San Bernardino County and regional partners on flood management and mitigation projects. The City also conducts ongoing maintenance and preparedness activities to help ensure that flood control and stormwater infrastructure function as intended during storm events. Flooding within the City may result from intense rainfall, flash flooding, debris flows, localized drainage issues, or the failure of flood-control facilities, which could inundate downstream areas.
Over the next five years, Rancho Cucamonga is expected to remain vulnerable to flooding associated with intense precipitation events, atmospheric rivers, debris flows, and localized drainage issues. While the City benefits from an extensive flood-control system, future storm events may produce short-duration, high-intensity rainfall that overwhelms drainage systems in some locations. Climate projections indicate that 15 Ibid.
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 77 Southern California may experience greater variability between dry and wet years, increasing the potential for both prolonged droughts and intense storm events.
Continued maintenance of flood-control facilities, drainage infrastructure improvements, emergency preparedness efforts, and floodplain management practices will remain important for reducing future flood-related impacts.
Dam Failure/Inundation
With the adoption of SB 92 in 2017, new dam safety requirements mandate that dam owners map the downstream inundation areas for dams governed by the California DWR. In addition to the mapping, owners must prepare Dam Emergency Action Plans that identify the emergency management plans and procedures in place for these facilities. Figure 3-9 (above) identifies the inundation areas mapped for these catch basins located within the City. For inundation to occur as depicted in this map, it is assumed that the reservoir behind the dam is full and that failure occurs suddenly, releasing water in a relatively short time. Failures typically occur due to earthquakes, erosion, design flaws, or water overflow during intense storms. Table 3-13 identifies the hazard potential of each catch basin (dam). Hazard potential classifications assigned by the NID reflect the potential consequences of a dam failure and do not indicate the structural condition or likelihood of failure of the facility.
TABLE 3-13. BASIN HAZARD POTENTIAL
Catch Basin Name* Hazard Potential Dam Function
Alta Loma Basin (1964), (1971)** High Flood Control
Cucamonga Creek (1980) High Flood Control
Day Creek (1988) High Debris Control
Deer Canyon (1980) High Flood Control
Demens Creek Debris Basin (1980) High Flood Control
Etiwanda Debris Basin (2008) High Flood Control
Hickory Basin Significant Flood Control
San Sevaine Basin (2004) High Flood Control
* The year indicates when the dam was completed
** NID lists two dams under this name; both with the same hazard potential, dam function, and inspection date: these are separate facilities represented as one table entry Source: National Inventory of Dams https://nid.sec.usace.army.mil/ords/f?p=105:1 Over the next five years, the probability of dam or catch basin failure within Rancho Cucamonga is expected to remain low due to ongoing inspection, maintenance, and regulatory oversight. However, because failure of one of these facilities could result in significant downstream flooding, infrastructure damage, transportation disruptions, utility impacts, and potential threats to life safety, dam failure remains a low-frequency
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 78 but high-consequence hazard. Continued maintenance, emergency planning, and coordination with San Bernardino County Flood Control and the California Division of Safety of Dams will remain important for reducing future risk.
Climate Change Considerations
Flooding
Atmospheric river events are expected to remain a significant driver of future flood risk throughout Southern California. Climate change is expected to affect precipitation patterns throughout California and may influence future flooding conditions in Rancho Cucamonga. Studies project that intense precipitation events in California may become more frequent and severe16, potentially increasing the risks of flooding, debris flows, erosion, and infrastructure stress during major storms. As a result, future flood management, maintenance, and infrastructure improvements may be necessary to address changing climatic conditions and support long-term community resilience.
Dam Failure/Inundation
Climate change may indirectly affect dam safety by increasing the frequency and intensity of extreme precipitation events, altering runoff patterns, and increasing hydrologic variability. More intense storms may place additional stress on flood-control facilities, catch basins, and reservoirs, while prolonged drought conditions may affect watershed conditions, sediment transport, and vegetation cover. Although climate change is not expected to directly cause dam failures, changing hydrologic conditions may increase operational and maintenance challenges for flood-control infrastructure.
Continued inspection, maintenance, and emergency planning will remain important to ensure the long-term reliability of these facilities.
16 Polade, S.D., Gershunov, A., Cayan, D.R., Dettinger, M.D., & Pierce, D.W. 2017. Precipitation in a warming world: Assessing projected hydro-climate changes in California and other Mediterranean climate regions.
Scientific Reports. https://www.nature.com/articles/s41598-017-11285-y
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 79 HAZARD PROFILE: SEVERE WEATHER
The severe weather hazard profile includes discussions regarding drought, extreme heat, and severe wind. For additional information and analysis regarding severe weather effects associated with climate change, please refer to the Greenhouse Gas Emissions and Climate Change Vulnerability Assessment Existing Conditions Report, prepared as part of the General Plan17.
Description
Extreme Heat
Extreme heat is a period when temperatures are abnormally high relative to the normal temperature range. There are generally three types of extreme heat events:
• Extreme Heat Days: A day during which the maximum temperature surpasses 98 percent of all historic high temperatures for the area, using the time between April and October from 1950 to 2005 as the baseline.
• Warm Nights: A day between April and October when the minimum temperature exceeds 98 percent of all historic minimum daytime temperatures observed between 1950 and 2005.
• Extreme Heat Waves: A series of successive extreme heat days and warm nights where extreme temperatures do not abate; while no universally accepted minimum length of time for a heatwave event exists, Cal-Adapt considers four successive extreme heat days and warm nights to be the minimum threshold for an extreme heatwave.
Drought
A drought is a long period of substantially reduced precipitation. The primary direct impact of a drought is the reduction of available water supplies. This is particularly concerning in agricultural areas and natural environments, but it can also affect urban areas. Droughts can harm landscapes because plants do not get the water that they need to survive. In severe cases, droughts may pose a risk to human health if available water supplies are insufficient to meet basic needs.
Indirectly, drought causes soils to dry out, making them harder and less able to absorb water. When precipitation returns, the soil absorbs less water, increasing runoff and potentially leading to flooding. Dry soils are more susceptible to erosion, especially if plants have died or no longer provide stability due to root loss and changes in soil 17 https://www.CityofRC.us/sites/default/files/2020-
06/PlanRC_ExistingConditionsReport_Vulnerability%26GHG_May2020.pdf
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 80 composition. Drought causes many plants in natural areas to dry out, making them more susceptible to pests and diseases and to increased wildfire risk.
Severe Wind
Wind is simply the movement of air caused by differences in atmospheric pressure and temperature. High-pressure air will naturally move to areas of low pressure. Usually, the distance between these high- and low-pressure zones is large; however, on occasion, they may be near one another. When this happens, air will flow dramatically, creating high-speed winds. The most common severe wind event affecting Southern California is the Santa Ana wind, which is characterized by strong, dry offshore winds that typically occur during the fall and winter months.
When winds are fast enough, they can damage homes, public facilities, utilities, and other infrastructure. They can also uproot or topple mature trees or pick up debris and send it careening through the air. This debris can injure or even kill bystanders who may find themselves stranded outside. High-speed winds can also deposit this debris in the middle of rights-of-way, such as roads, freeways, and railways, blocking exit routes for would-be evacuees or impeding access to first responders trying to reach wounded people.
Location and Extent
Extreme Heat
Extreme heat events will feel different from region to region since different areas have different historical high temperatures. For example, an extreme heat day on the coast will feel different than an extreme heat day in the High Desert. The reason for this is that humidity affects the perceived heat people feel. Humid conditions will make a day feel hotter than a non-humid day, even when the temperature is the same. The difference between the perceived temperature and the actual temperature is known as the “heat index.” To illustrate the effect of the heat index, a 90-degree day with 50 percent humidity feels like 95°F, whereas a 90°F day with 90 percent humidity feels like 122°F. Figure 3- 10 illustrates the National Oceanic and Atmospheric Administration (NOAA)’s National Weather Service Heat Index.
Extreme heat events are not limited to any part of the City. They occur with the same intensity and duration at the same time across all locations in Rancho Cucamonga. For Rancho Cucamonga, an extreme heat day involves a temperature exceeding 103.9°F, and a warm night involves a temperature exceeding 68.7°F.18 18 https://cal-adapt.org/tools/extreme-heat/
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 81 Figure 3-10. NOAA National Weather Service Heat Index Drought
Droughts are somewhat frequent in California and typically occur when precipitation is limited for an extended period. Rain arrives in California via atmospheric rivers (channels of moist air located high in the atmosphere) and the El Niño Southern Oscillation (ENSO) cycle (a regional meteorological phenomenon in the southern Pacific Ocean). This cycle typically gives rise to two distinct phases: El Niño, the warm and wet phase, and La Niña, the dry and cold phase. When California experiences a drought, it is typically due to fewer atmospheric rivers or an active La Niña phase, leading to belowaverage precipitation. Drought may also occur when areas where water sources are located experience drought, even if the local region does not. Table 3-14 identifies the drought classifications used by the US Drought Monitor program. This classification system synthesizes multiple different scales into a descriptive index.
Communities that rely on water from other parts of the state and feel the effects of drought may experience drought differently than communities that source their water locally. Currently, the Cucamonga Valley Water District sources almost half of its water from imported sources that may come from outside the region.19 Droughts are regional events, so all parts of Rancho Cucamonga face the same risk.
However, urban areas will likely experience different effects than open space areas. It is also possible for communities to experience a “long-distance drought” because many urban areas in California receive water from long distances. If these distant areas 19 Cucamonga Valley Water District. https://www.cvwdwater.com/133/Water-Supply
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 82 experience drought, it may cause water shortages in the urban areas that rely on them, even if those areas are receiving normal precipitation.
TABLE 3-14. US DROUGHT MONITOR CLASSIFICATION SCHEME
Category Description Possible Impacts
D0* Abnormally dry Slower growth of crops and pastures.
D1 Moderate drought
Some damage to crops and pastures. Water bodies and wells are low. Some water shortages may occur or may be
imminent. Voluntary water use restrictions can be requested.
D2 Severe drought Likely crop and pasture losses. Water shortages are common, and water restrictions can be imposed.
D3 Extreme drought Major crop and pasture losses. Widespread water shortages and restrictions.
D4 Exceptional drought Exceptional and widespread crop and pasture losses.
Emergency water shortages develop.
* D0 areas are those under “drought watch” but not technically in a drought. They are potentially heading into drought conditions or recovering from drought but not yet back to normal.
Source: US Drought Monitor. 2019. “Drought Classification.” Severe Wind
In Southern California, the most common type of severe wind event is called the Santa Ana winds. High pressure over Nevada and Utah, often during the fall and winter months, forces air down from the high desert toward the ocean. As the winds descend, they warm and accelerate, sometimes carrying particulate matter and worsening the respiratory health of those with allergies. Rancho Cucamonga is often affected by Santa Ana winds blowing through the San Gabriel and San Bernardino Mountain ranges via the Cajon Pass. Santa Ana winds are a contributing factor to the threat and spread of wildfires in California. Santa Ana winds can damage electrical distribution infrastructure, creating wildfire ignitions from arcing or downed power lines. Santa Ana winds can also cause the rapid spread of otherwise contained or small fires, such as vehicle fires or those caused by discarded smoking materials. More information on this is available in the “Wildfire” section. Depending on the severity of the wind event, any part of the City can be affected.
Generally, winds are measured using the Beaufort scale, developed in 1805, which categorizes wind events on a force scale from 0 to 12 using their speed and impacts.
Any wind classified as force nine or above is generally considered a severe wind event.
Table 3-15 identifies the Beaufort scale, which classifies wind events in detail.
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 83 TABLE 3-15. BEAUFORT SCALE
Force Speed (mph) Description
0 0 to 1 Calm: Smoke rises vertically, and the sea is flat. 1 1 to 3 Light air: The direction of wind is shown by smoke drift, but not wind vanes.
2 4 to 7 Light breeze: Wind is felt on the face, leaves rustle, and wind vanes are moved. Small wavelets appear on the ocean, but do not break. 3 8 to 12
Gentle breeze: Leaves and small twigs are in motion, and light flags are extended. Large wavelets appear on the ocean, and crests begin to break.
4 13 to 18 Moderate breeze: Dust and loose paper become airborne, and small branches are moved. Small waves appear on the ocean.
5 19 to 24 Fresh breeze: Small trees begin to sway and moderate waves form. 6 25 to 31 Strong breeze: Large branches are in motion, and using an umbrella becomes difficult. Large waves begin to form.
7 32 to 38 Near gale: Whole trees are in motion, and walking against the wind can be hard. Foam from breaking waves is blown in streaks. 8 39 to 46 Gale: Walking is difficult, and twigs break off trees. 9 47 to 54 Severe gale: Slight structural damage. Crests of waves begin to topple. 10 55 to 63 Storm: Trees are uprooted and considerable damage to structures.
Very high waves form in long, overhanging crests.
11 63 to 72 Violent storm: Widespread damage. Exceptionally high waves form, and the ocean is completely covered in foam.
12 73 and above Hurricane: Devastating damage. On the ocean, the air is filled with foam and spray.
Source: https://www.weather.gov/mfl/beaufort
Past Events
Extreme Heat
Based on Cal-Adapt's historical data (1950 through 2005), the City experiences four extreme heat days per year. During this same period, the City experienced a 4-day heatwave, which occurs approximately every 5 years. Over the past 21 years (1999– 2019), the city has experienced an extreme heat event (103°F or higher) every year except in 2005. During this period, the temperature averaged 108.4°F. The four highest temperatures occurred in 2006 (114°F), 2017 (114°F), 2018 (117°F), and 2020 (117°F).20
20 NOAA National Centers for Environmental Information, https://www.ncdc.noaa.gov/cdoweb/datasets/GSOY/stations/GHCND:USW00003102/detail
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 84 Since the adoption of the 2021 LHMP, Southern California has continued to experience periods of extreme heat. During 2022, 2023, 2024, and 2025, Rancho Cucamonga experienced multiple heat events with temperatures exceeding 100°F. These events resulted in increased cooling demand, elevated energy consumption, and heightened risks for heat-related illness throughout the region. The persistence of extreme heat events during the planning period underscores Rancho Cucamonga's continued vulnerability to excessive temperatures.
Drought
Rancho Cucamonga, like the rest of California, has experienced numerous droughts throughout its history. Each event has been distinct, with varying lengths, severity, and frequency.
One of the earliest recorded major droughts in state history is known as the “Great Drought,” which occurred in 1863 and 1864. This drought killed 46 percent of the cattle in the state and ultimately led to the decline of cattle ranching. The “Dust Bowl Droughts,” lasting from 1928 to 1935, had a significant impact on the state’s agriculture.
The effects of this drought were so severe that it sparked the movement to create some of California’s modern water irrigation infrastructure, such as the California Aqueduct.
Another drought occurred in 1976 and 1977, which led to agricultural losses estimated at nearly $1 billion. Implementation of water-saving practices resulted from this drought, which are still in effect today across the state. Further water conservation practices were enacted during a drought lasting from 1987 to 1993, which caused an estimated $250 million in agricultural damage each year.
California experienced its most recent drought beginning in 2012 and lasting until 2017.
All areas of the state were affected, and by 2014, it was considered the most severe drought in 1,200 years. Figure 3-11 illustrates the severity of the drought conditions experienced over the past 19 years.
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 85 Figure 3-11. California Drought Conditions 2000–2025 21 By the summer of 2014, almost all of California was experiencing D2 (Severe Drought) conditions. Rancho Cucamonga, all of San Bernardino County, and more than 75 percent of California were reported to be experiencing the most intense level of drought, D4 (Exceptional Drought). By 2015, emergency water-saving mandates were enacted, requiring all jurisdictions to reduce water use by at least 25 percent. In late 2016 and early 2017, successive heavy rains helped end the drought conditions in the state. The following winter, in late 2017 and early 2018, rains did not return in the same quantity, and slight drought conditions returned across California. This moderate drought was again abated during the winter of late 2018 and early 2019, when heavy rains ended any remaining drought conditions.
As of February 2021, parts of California are experiencing conditions that range from abnormally dry to exceptional drought. The majority of extreme drought conditions are concentrated in the counties north of the San Francisco Bay region and in eastern California, while Southern California is predominantly experiencing abnormally dry to moderate drought conditions.
Severe Wind
Severe wind events are common in the City. Annually, the City is subjected to Santa Ana Wind conditions that can cause significant damage to trees, buildings, and vehicles.
The following are significant events that have affected the City and region in the past:
• On May 5, 1998, strong thunderstorms across the region caused high winds that shredded the roof of an auto repair shop in Rialto. 21 U.S. Drought Monitor. https://droughtmonitor.unl.edu/DmData/TimeSeries.aspx
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 86 • On January 6, 2003, a strong Santa Ana windstorm knocked down power lines and trees, damaged structures, and generated dust, impacting residents and businesses. The City received nearly 60 calls for service due to this event. • On March 4, 2005, a small tornado touched down in Fontana. The tornado blew shingles off three homes, knocked down power lines and several trees, and ripped the roof off a water well building.
• A strong Santa Ana wind event on December 28, 2006, knocked down trees and power lines throughout the region.
• A storm in early December of 2011 produced wind speeds exceeding 65 mph, knocking down hundreds of trees, downing power lines, and overturning trucks throughout the San Bernardino Valley. Later that month, another strong storm caused 45 to 65 mph winds, with one recorded gust of at least 70 mph. • A storm system that hit the region in late January of 2012 caused wind gusts over 60 mph, knocking down power lines and blowing containers off semitrucks. • In early March of 2012, strong winds affected the San Bernardino Valley region following a storm, with gusts exceeding 60 mph.
• On April 30, 2014, a Santa Ana wind event contributed to the rapid southwest spread of the Etiwanda Fire. Wind gusts exceeding 100 mph were recorded during the fire.
• A Santa Ana wind event in November of 2014 caused winds of approximately 50 mph, with damage reported throughout the region.
• In January of 2017, a series of three storms brought strong winds that knocked down hundreds of trees throughout the region, resulting in millions of dollars in damage.
• On October 9, 2017, a strong Santa Ana wind event caused wind gusts of 70 mph.
• On October 26 and 27, 2020, the City experienced extreme wind gusts exceeding 65 mph, resulting in extensive damage to trees, sidewalks, traffic signals, and ballfield lighting. Southern California Edison activated their PSPS, which affected over 1000 customers with loss of power for up to 24 hours. • In January 2023, a series of winter storms brought periods of strong winds across Southern California, resulting in downed trees, power outages, roadway hazards, and localized property damage throughout the region. • During February and March 2023, multiple atmospheric river storms affected Southern California, producing periods of strong winds associated with frontal systems. Wind-related impacts included downed trees, utility disruptions, transportation delays, and increased strain on regional infrastructure.
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 87 • In 2024 and 2025, Southern California continued to experience seasonal Santa Ana wind events capable of producing localized power outages, downed trees, hazardous driving conditions, and elevated wildfire risk, demonstrating the ongoing threat posed by severe wind events in Rancho Cucamonga and the surrounding region.
Since the adoption of the 2021 LHMP, drought conditions in California have varied considerably. As shown in Figure 3-12, much of the state was experiencing severe-toexceptional drought conditions in June 2022, following multiple years of below-average precipitation and persistent dryness. Drought conditions improved substantially during 2023 and 2024 due to a series of significant winter storms and atmospheric river events that increased snowpack, reservoir storage, and soil moisture throughout much of California. However, drought conditions began to re-emerge in portions of the state during 2025 as precipitation levels declined and warmer temperatures increased evaporative demand. While Rancho Cucamonga did not experience the most severe drought conditions observed elsewhere in California during this period, the variability in recent U.S. Drought Monitor data demonstrates the region's continued vulnerability to changing precipitation patterns, water supply challenges, and prolonged drought. These recent trends highlight the importance of continued drought preparedness, water conservation efforts, and long-term climate resilience planning.
Figure 3-12. U.S. Drought Monitor Conditions in California (June 2022–June 2025) 22
22 U.S. Drought Monitor, National Drought Mitigation Center, USDA, and NOAA. Maps accessed June 2026.
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 88 Risk of Future Events
Extreme Heat
According to Cal-Adapt data archives powered by the NOAA databanks, Rancho Cucamonga does experience extreme heat days. The City historically (1950–2005) experienced an average of 4 extreme heat days annually, based on the data provided.
The number of days increased to 8 days annually from 2006 to 2019. According to CalAdapt's projected models, the City is projected to experience between 21 and 35 extreme heat days annually from 2050 to 2099.23
Looking ahead to the next five years, Rancho Cucamonga is expected to experience more frequent extreme heat events. Climate projections indicate that average temperatures will continue to rise across Southern California, resulting in more days exceeding historical temperature thresholds and an increased likelihood of prolonged heatwaves. Extreme heat poses risks to public health, particularly for older adults, young children, outdoor workers, and individuals with underlying health conditions.
Increased cooling demands may also strain energy infrastructure and increase the risk of power disruptions during periods of high electricity demand. Continued public education, cooling center planning, urban forestry efforts, and heat mitigation measures will remain important during the planning horizon.
Drought
Drought will remain a foreseeable hazard for Rancho Cucamonga throughout the planning horizon. Climate change is expected to increase temperatures, alter precipitation patterns, and contribute to greater variability between wet and dry periods across Southern California. These changes may increase the severity and duration of future drought conditions while placing additional stress on water supplies, vegetation, and natural resources. Recent U.S. Drought Monitor data demonstrates how quickly conditions can shift from severe drought to near-normal conditions and back again, highlighting the region's continued vulnerability to prolonged dry periods.
Looking ahead to the next five years, Rancho Cucamonga is expected to remain vulnerable to recurring drought conditions and water supply challenges. While individual wet years may temporarily improve drought conditions and replenish reservoirs and groundwater supplies, drought remains a cyclical hazard throughout California. In addition, warmer temperatures are expected to increase evapotranspiration rates, reduce soil moisture, and increase demand on water resources. As a result, drought conditions similar to those experienced during the 2020–2022 drought period may recur 23 Greenhouse Gas Emissions and Climate Change Vulnerability Assessment Existing Conditions Report., https://www.CityofRC.us/sites/default/files/2020-
06/PlanRC_ExistingConditionsReport_Vulnerability%26GHG_May2020.pdf
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 89 within the planning horizon of this LHMP. Continued water conservation efforts, regional water supply planning, groundwater management, and climate adaptation initiatives will remain important for reducing future drought impacts within the City.
Figure 3-13 illustrates drought conditions in California as of this Plan update.
Figure 3-13. US Drought Monitor – California, 2026 24
Severe Wind
Given Rancho Cucamonga’s history of severe wind events, it is very likely that wind events will continue to impact the city. Severe wind events may damage transmission lines, distribution infrastructure, substations, and utility equipment, resulting in localized or widespread power outages. The most likely source of these events in the future will be the Santa Ana winds or extreme storms. All expectations are that they will occur again in the future.
Rancho Cucamonga's history of severe wind events, future occurrences are highly likely during the planning horizon. The most common source of severe winds will continue to 24 U.S. Drought Monitor, National Drought Mitigation Center, USDA, and NOAA. https://droughtmonitor.unl.edu/CurrentMap/StateDroughtMonitor.aspx?CA
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 90 be Santa Ana wind events and strong winter storm systems. Severe winds may damage buildings, trees, electrical transmission and distribution infrastructure, communication systems, and transportation facilities. Wind events may also result in PSPS, localized power outages, hazardous driving conditions, and increased wildfire risk. Over the next five years, Rancho Cucamonga is expected to remain vulnerable to recurring severe wind events and their associated impacts.
Climate Change Considerations
Extreme Heat
The primary effect of climate change is warmer average temperatures. The hottest years on record have occurred since 2000, with 2016 and 2020 tied for the hottest.25 As climate change accelerates in the 21st century, extreme heat events are expected to become more frequent and intense in the City. With projections indicating that extreme heat days could increase by 21 to 35 days annually by the end of the century, the City can expect a shift in residential and business needs for cooling and addressing heatrelated issues.
Drought
Climate change is expected to increase the frequency, duration, and severity of drought conditions throughout California, including Rancho Cucamonga. Scientific studies project warmer temperatures, reduced snowpack, increased evapotranspiration, and more frequent periods of below-average precipitation, all of which may contribute to future water supply challenges. Climate change is also expected to increase variability between wet and dry years, resulting in more pronounced drought cycles and greater uncertainty in water resource management.
Rancho Cucamonga relies on both local groundwater and imported water supplies. As temperatures rise, water demand is expected to increase, while the reliability of imported water sources may be affected by reduced Sierra Nevada snowpack and shifts in runoff patterns. These conditions may place additional pressure on regional water systems and increase the importance of water conservation, groundwater management, and long-term water supply planning.
Although individual wet years may temporarily alleviate drought conditions, drought is expected to remain a recurring hazard throughout the planning horizon. Continued 25 Rebecca Hersher and Lauren Sommer. 2020. “2020 May be the Hottest Year on Record. Here’s the Damage it did.” NPR. https://www.npr.org/2020/12/18/943219856/2020-may-be-the-hottest-year-on-record-heres-thedamage-it-did
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 91 adaptation efforts by regional water agencies and local conservation programs will be important for reducing future drought-related impacts.26 Severe Wind
It is anticipated that atmospheric rivers delivering storms to Southern California may intensify due to climate change. While the average number of storms in Southern California will remain the same, the number of storms is expected to increase by 10 to 20 percent.27 This increase in storm intensity may also bring stronger winds to Southern California, including Rancho Cucamonga.
Regarding Santa Ana winds, however, studies indicate that these events may be affected in varying ways. According to one study that examined two global climate models, there is a projected increase in future Santa Ana events. However, other studies have found that the number of Santa Ana events may decrease by about 20% in the future.28 Although scientific studies vary regarding future Santa Ana wind frequency, climate change may increase the severity of wind-related impacts by contributing to drier vegetation, elevated wildfire conditions, and more intense storm systems. 26 Cal-Adapt Climate Tools and California Department of Water Resources. 27 Atmospheric Rivers to Soak California as Climate Warms. https://www.livescience.com/49225-atmosphericrivers-double-climate-change.html 28 Hall, Alex, Neil Berg, Katharine Reich. (University of California, Los Angeles). 2018. Los Angeles Summary Report. California’s Fourth Climate Change Assessment. https://www.energy.ca.gov/sites/default/files/2019- 11/Reg%20Report-%20SUM-CCCA4-2018-007%20LosAngeles_ADA.pdf
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 92 HAZARD PROFILE: HUMAN-CAUSED HAZARDS
The Human-Caused Hazards profile includes discussions of cyber threats and terrorism/mass-casualty incidents. It is important to note that while these hazards are not generally considered natural, they are a concern identified by the Committee. Future updates to the City’s EOP will expand on these hazards, where appropriate.
Description
Cyber Threat
Cyber threats occur when an individual or group threatens or attempts to disrupt computer networks, systems, or data belonging to private citizens, religious groups, educational institutions, government agencies, or businesses. These threats take the form of online harassment, hacking, or in-person tampering with electronic equipment.
Successful cyberattacks can lead to service disruptions, infrastructure damage, theft, and severe incidents that may cause injury or death.
Terrorism/Mass Casualty Incident
Terrorism is the use or threat of force to achieve a particular social or political outcome.
The goals of terrorism may sometimes be overturning a government, the reversal of public policy, the release of political prisoners, and other such motives. Acts of terror may overlap with acts of war or hate crimes. Generally, terrorism involves an attempt to kill or seriously harm people, or an attempt to disrupt civil society by destroying property or infrastructure, attacking government operations at all levels, interrupting essential public services, creating chaos, or a combination of some or all these goals. In extreme situations, terrorists may gain access to mass destruction weapons, terrorists may gain access to mass destruction weapons, including bioweapons, chemical agents, radioactive materials, or high-yield explosives. It should be noted that these events are infrequent. While incidents of terror caused by foreign individuals or groups receive significant media and public attention, most acts of terror in the United States have been caused by domestic terrorists.
A mass casualty incident is a situation in the United States in which emergency medical services resources, such as personnel and equipment, are overwhelmed by the number and severity of casualties. The more commonly recognized events of this type include building collapses, train and bus collisions, plane crashes, earthquakes, and other largescale emergencies. The most common types are generally caused by terrorism, masstransportation accidents, or natural disasters. Events such as the Oklahoma City bombing in 1995 and the September 11 attacks in 2001 are well-publicized examples of mass casualty incidents.
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 93 Transportation Accident
Transportation accidents involve incidents affecting roadways, rail systems, air transportation, and the movement of hazardous materials. Rancho Cucamonga is served by several major transportation corridors, including Interstate 10 (I-10)29, Interstate 15 (I-15), State Route 210 (SR-210), the Metrolink San Bernardino Line, freight rail corridors, and proximity to Ontario International Airport and Cable Airport.
The high volume of passenger vehicles, commercial trucks, rail traffic, and aircraft operating within and near the City creates the potential for transportation-related accidents.
Transportation accidents may involve passenger vehicles, commercial trucks, trains, aircraft, or the release of hazardous materials during transportation. Potential impacts include fatalities, injuries, roadway closures, infrastructure damage, transportation network disruptions, environmental contamination, and interruptions to emergency response operations. The severity of a transportation accident depends on factors such as the type of transportation involved, the number of people affected, the presence of hazardous materials, weather conditions, and proximity to populated areas or critical facilities.
Major transportation corridors within Rancho Cucamonga serve both regional and interstate travel and freight movement. As a result, transportation accidents can affect not only travelers and transportation infrastructure but also nearby residents, businesses, and critical facilities through traffic disruptions, evacuations, hazardous materials releases, and other secondary impacts.
Location and Extent
Cyber Threat
Since computers are so ubiquitous, a cyber threat could appear in virtually any part of the City. In extreme circumstances, a threat could impact the entire city. Cyber threats vary in length and severity of impact. A minor threat could simply cause computer systems to slow down for a few minutes and not behave responsively. On the other hand, a major cyber threat could cause a complete shutdown of critical systems, including those used by banks, healthcare institutions, universities, major businesses, and city governments.
Cyber threats are not measured on any scale, but they can be assessed by determining:
29 A segment of Interstate 10 runs along the southern border of Rancho Cucamonga. This stretch extends to Etiwanda Avenue just east of Interstate 15 and is officially part of the SB Express Lanes on I-10 project.
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 94 • The type of incident (website defacement, denial of service, unauthorized surveillance)
• The use of malicious software
• The level of security countermeasures that failed in preventing the cyber threat • The duration of the cyber threat (a few hours, a few days, several weeks, etc.) Common cyber threats include:
• Phishing
• Ransomware
• Intellectual Property Theft
• Spyware/Malware
• Vulnerable and Unpatched Software
• Distributed Denial of Service (DDoS)
• Crypto-mining
To understand the how pervasive cybercrime is the Federal Bureau of Investigation publishes the following statistics:
• Total cybercrime complaints
• Financial losses
• Complaint types
• Critical infrastructure attacks
• State-by-state statistics
Between 2019 and 2024, total losses from reported cybercrimes have increased from $3.5 billion to $16.6 billion (involving 859,532 complaints). Figure 3-14 depicts the change over time for these incidents. According to their latest annual report, losses for 2025 exceeded $20 billion.
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 95 Figure 3-14. FBI IC3 Reported Annual Financial Losses from Cyber-Enabled Crime (2019–2025)
Terrorism/Mass Casualty Incident
Mass Casualty Incidents can occur anywhere, although public spaces and locations where many people congregate (parks, schools, places of worship, government facilities, shopping centers, and areas of public gathering) are most common. Critical locations in Rancho Cucamonga may be large shopping centers (i.e., Victoria Gardens), governmental facilities (i.e., City Hall and Rancho Cucamonga Superior Court (it should be noted that these two facilities are in very close proximity to each other)), universities and colleges (i.e., Chaffey College), schools, medical facilities (i.e., San Antonio’s Regional Center for Aging, Kindred Hospital, and the Loma Linda University VA), parks (i.e., Central Park), and large employers within the City.
Acts of terrorism may occur at the locations listed above; however, the perpetrators may also target high-value facilities, such as power-generating facilities, water treatment plants, dams or reservoirs, railroads, highways, and other facilities that could impact governmental operations and services.
Mass Casualty Incidents and acts of terrorism are typically measured by the fatalities, injuries, and destruction they cause, but there is no universally used scale for measuring these events.
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 96 Transportation Accident
Transportation accidents can occur throughout Rancho Cucamonga but are most likely along major transportation corridors and facilities that experience high traffic volumes.
Key transportation routes serving the City include Interstate 10 (I-10), Interstate 15 (I15), State Route 210 (SR-210), Foothill Boulevard (Historic Route 66), Haven Avenue, Etiwanda Avenue, and other major arterial roadways. Rail-related accidents may occur along the Metrolink San Bernardino Line and freight rail corridors that traverse the City.
In addition, aircraft-related incidents could affect areas within or near the flight paths associated with Ontario International Airport and Cable Airport.
The extent of a transportation accident depends on the type of transportation involved, the number of vehicles or passengers affected, the presence of hazardous materials, and the location of the incident. Most transportation accidents are localized events that affect a limited area; however, major incidents involving multiple vehicles, trains, aircraft, or hazardous materials may have broader consequences, including roadway closures, evacuations, injuries, fatalities, environmental contamination, and disruption of critical transportation routes.
Transportation accidents involving hazardous materials have the potential to affect areas beyond the immediate accident site through spills, fires, explosions, or the release of hazardous substances. Similarly, accidents occurring along major transportation corridors may disrupt regional travel, freight movement, emergency response activities, and access to businesses and critical facilities. The severity of impacts generally increases when incidents occur in densely developed areas, near schools, healthcare facilities, or locations with high concentrations of people.
Past Events
Cyber Threat
The City of Rancho Cucamonga has not experienced a publicly reported cyber incident that has significantly disrupted municipal operations. However, several local and regional agencies have experienced cyber incidents in recent years, underscoring the ongoing threat posed by ransomware, phishing campaigns, data breaches, and other malicious activity. Examples include:
• In December 2023, the Municipal Water District of Orange County experienced a cybersecurity incident that disrupted portions of its information technology systems. The District implemented response procedures, isolated affected
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 97 systems, and coordinated with cybersecurity professionals to investigate and mitigate impacts.30
• On August 15, 2024, the Cucamonga Valley Water District (CVWD) experienced a ransomware-related cybersecurity incident that disrupted portions of its information technology systems, including phone services and payment processing functions. Water service and water distribution operations were not affected because operational systems were maintained on separate networks.
CVWD immediately activated its incident response procedures, engaged cybersecurity specialists, notified federal law enforcement, and restored affected systems within weeks. No ransom payment was made. This incident demonstrated the vulnerability of local utility providers to cyber threats and highlighted the importance of cybersecurity planning, system segmentation, and business continuity measures.31
• In 2024, numerous California public agencies and local governments continued to experience attempted ransomware attacks, phishing campaigns, and network intrusions targeting operational systems, employee accounts, and sensitive information. These incidents reflect a broader nationwide increase in cyber threats affecting government agencies, utilities, healthcare providers, educational institutions, and critical infrastructure organizations.32 • In July 2024, the CrowdStrike software outage affected organizations worldwide, including government agencies, transportation systems, healthcare providers, and businesses. Although the event was not the result of a malicious cyberattack, it demonstrated how technology failures affecting widely used software can disrupt critical services and operations on a global scale.33 Cyber threats have evolved significantly in recent years and increasingly target government agencies, critical infrastructure, healthcare systems, utilities, transportation networks, and third-party service providers. Many recent cyber incidents have demonstrated that disruptions to a single vendor or service provider can create cascading impacts across multiple sectors and geographic regions. While Rancho Cucamonga has not experienced a publicly reported cyber incident of national significance, the City relies on interconnected information technology systems, cloudbased services, communications networks, utility providers, and third-party vendors that may be vulnerable to cyberattack, ransomware, system failures, or data breaches.
Table 3-16 identifies several significant cyber incidents that have occurred in recent years and demonstrates the growing scale and complexity of cyber threats facing public and private organizations.
30 https://californiacountynews.org/news/2023/10/orange-county-district-attorneys-office-hit-cyber-attack 31 https://www.cvwdwater.com/m/newsflash/Home/Detail/309 32 https://www.cisa.gov/stopransomware/official-alerts-statements-cisa 33 https://www.congress.gov/crs-product/IF12717
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 98 TABLE 3-16. SELECTED SIGNIFICANT CYBER INCIDENTS (2024–2025) Incident Year Sector Affected Potential Local Relevance Change Healthcare
Ransomware
Attack 34
2024 Healthcare Disrupted medical claims processing,
prescriptions, and healthcare operations
nationwide; affected an estimated 190+ million
individuals.
CDK Global
Ransomware
Attack 35
2024 Transportation /
Business
Operations
Disrupted operations at approximately 15,000
automobile dealerships nationwide,
demonstrating the risks of supply chain and
vendor dependence.
CrowdStrike
Software Outage36
2024 Critical
Infrastructure / IT
Systems
Caused widespread disruptions to
transportation, healthcare, government, and
business systems worldwide due to software
update failure.
Conduent Data
Breach37
2025 Government
Services
Affected a major government contractor
supporting state and local agencies and
exposed sensitive information of millions of
individuals.
Ghost Ransomware
Campaign38
2025 Government &
Critical
Infrastructure
FBI and CISA reported attacks against
government agencies, healthcare
organizations, educational institutions, and
critical infrastructure operators worldwide.
Healthcare Sector
Cyberattacks 39
2024-
2025
Healthcare Cyberattacks continued to increase across
healthcare systems, demonstrating ongoing
risks to critical public services.
Terrorism/Mass Casualty Incident
The City of Rancho Cucamonga has not experienced a direct terrorist attack or mass casualty incident resulting in widespread loss of life. However, Southern California and California have experienced several significant incidents that demonstrate the potential impacts of terrorism, active shooter events, and other mass casualty incidents. • In December 2015, a mass shooting and terrorist attack occurred at the Inland Regional Center in San Bernardino, approximately 21 miles east of Rancho 34 https://www.aha.org/change-healthcare-cyberattack-underscores-urgent-need-strengthen-cyber-preparednessindividual-health-care-organizations-and? 35 https://www.extrahop.com/blog/CDK-Global-Ransomware-Attack-Sends-Shockwaves 36 https://pmc.ncbi.nlm.nih.gov/articles/PMC12276631/
37 https://www.techradar.com/pro/security/conduent-admits-its-data-breach-may-have-affected-around-10-millionpeople 38 https://www.businessinsider.com/ghost-cyberattacks-ransomware-what-you-need-to-know-2025-2 39 https://www.axios.com/2024/06/13/ransomware-cyberattack-change-healthcare
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 99 Cucamonga. The attack resulted in 14 fatalities and 22 injuries. Federal investigators later determined that the attackers had been inspired by foreign terrorist ideology.40
• In October 2017, a gunman opened fire on attendees at the Route 91 Harvest Festival in Las Vegas, Nevada, killing 58 people and injuring hundreds more.
Many California residents were among the victims, highlighting the regional impacts that large-scale mass casualty incidents can have on California communities.41
• In July 2019, a mass shooting occurred at the Gilroy Garlic Festival in Gilroy, California, resulting in three fatalities and numerous injuries. The incident demonstrated the vulnerability of large public events and community gatherings to targeted acts of violence.42
• In May 2021, a mass shooting at a Santa Clara Valley Transportation Authority (VTA) rail yard in San Jose resulted in nine fatalities, including the attacker. The incident disrupted transportation operations and highlighted the potential vulnerability of critical infrastructure and public-sector facilities.43 • In January 2023, a mass shooting in Monterey Park, California, resulted in 11 fatalities and multiple injuries during a Lunar New Year celebration. The incident demonstrated the potential for mass casualty events to occur at community gatherings and cultural events.44
These incidents demonstrate that terrorism, targeted violence, active shooter events, and other mass casualty incidents continue to pose a potential threat to California communities. Although Rancho Cucamonga has not experienced a comparable event, the City's public facilities, transportation corridors, community events, commercial centers, and other gathering places could potentially be affected by similar incidents in the future.
Transportation Accident
Rancho Cucamonga's location near the intersection of Interstate 10, Interstate 15, and State Route 210, along major rail corridors, and its proximity to regional airports create ongoing exposure to transportation-related accidents. While most incidents are localized and involve limited impacts, major collisions, derailments, hazardous materials releases, and other transportation accidents have occurred throughout the region and have the potential to affect public safety, transportation networks, and critical 40 https://en.wikipedia.org/wiki/2015_San_Bernardino_attack 41 https://en.wikipedia.org/wiki/2017_Las_Vegas_shooting 42 https://en.wikipedia.org/wiki/Gilroy_Garlic_Festival_shooting 43 https://en.wikipedia.org/wiki/2021_San_Jose_shooting 44 https://en.wikipedia.org/wiki/2023_Monterey_Park_shooting
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 100
infrastructure. Table 3-17 summarizes reported freeway-related collisions in Rancho Cucamonga over the past 10 years. Information is reported only for SR 210 and Interstate 15, as those are the highways located within the City.
Aircraft-related transportation accidents are addressed separately in the Aircraft Incident profile.
TABLE 3-17. 10-YEAR HISTORY OF TRANSPORTATION ACCIDENTS ON THE 210 AND 15 FREEWAYS
Year State Route 210 Interstate 15 Total
2016 349 211 560
2017 360 209 569
2018 335 241 576
2019 392 238 630
2020 275 182 457
2021 335 237 572
2022 281 247 528
2023 341 226 567
2024 321 194 515
2025 290 290 580
Source: California Crash Reporting System (CCRS), Open Data. https://lab.data.ca.gov/dataset/ccrs Risk of Future Events
Cyber Threat
Given the integration of technology into the everyday lives of Rancho Cucamonga’s residents, businesses, and government operations, the risk of future cyber threats is high. While there have been no reported successful cyberattacks that have disrupted City operations, the City, like most public agencies, is threatened by cyberattacks daily.
Whether these attacks are successful depends on the use of appropriate security measures and protocols. Cyber threats targeting government agencies, utilities, healthcare providers, educational institutions, and critical infrastructure organizations continue to increase in frequency and sophistication. Because Rancho Cucamonga relies heavily on interconnected information technology systems, cloud-based services, communications networks, and third-party vendors, the likelihood of future cyber incidents affecting residents, businesses, or municipal operations remains high. While the success of future attacks depends largely on cybersecurity controls, employee
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 101
awareness, and system resilience, cyber threats are expected to remain an ongoing and evolving risk throughout the planning horizon.
Terrorism/Mass Casualty Incident
Given that mass casualty incidents and acts of terrorism, whether foreign or domestic, stem from a variety of factors: economics, societal pressures, mental health, geopolitics, warfare, religion, etc., it is impossible to predict when an incident will occur. While Rancho Cucamonga does not contain many facilities traditionally considered high-value national security targets, public gathering places, transportation facilities, community events, commercial centers, schools, and other public spaces could be vulnerable to targeted acts of violence or mass casualty incidents. Incidents of this type are more likely to be carried out by smaller organizations or individuals aligned with better-known organizations, although the effects may be no less significant. For this reason, mass casualty incidents and terrorism related events have the potential to occur within the City, the likelihood is still considered low. See Chapter 4 for further discussion regarding terrorism/mass casualty incident vulnerabilities in Rancho Cucamonga.
Transportation Accident
Transportation accidents will continue to occur in Rancho Cucamonga due to the presence of major transportation corridors, including I-10, I-15, SR 210, and regional rail facilities, as well as proximity to Ontario International Airport and Cable Airport. The City experiences substantial daily traffic volumes from passenger travel, commercial trucking, freight movement, and regional commuting. As population growth and transportation activity continue throughout the Inland Empire, the potential for transportation-related accidents is expected to remain.
Most transportation accidents are localized events with limited impacts; however, major collisions involving multiple vehicles, commercial trucks, rail operations, aircraft, or hazardous materials can cause significant injuries, fatalities, environmental impacts, evacuations, and prolonged transportation disruptions. Incidents involving hazardous transportation materials may result in additional consequences, including roadway closures, emergency response operations, and impacts to nearby residents, businesses, and critical facilities.
Given Rancho Cucamonga’s location along several major regional transportation corridors, transportation accidents are expected to remain a recurring hazard throughout the planning period. While most incidents are relatively minor, occasional high-consequence events can affect public safety, transportation networks, and critical infrastructure throughout the City.
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Climate Change Considerations
Cyber Threat
Climate change is not expected to directly increase the frequency of cyber threats.
However, climate-related hazards such as extreme heat, severe weather, wildfires, and power outages may affect information technology infrastructure, communications systems, data centers, and utility operations. Increased reliance on technology, remote communication, and interconnected systems during emergencies may also heighten the consequences of cyber incidents. Overall, climate change is expected to have a limited indirect influence on cyber threat vulnerability within Rancho Cucamonga.
Terrorism/Mass Casualty Incident
Although some research suggests climate change may contribute to broader social, political, economic, or resource-related stresses in certain regions, the relationship between climate change and terrorism or mass casualty incidents remains uncertain.
Any influence would likely occur indirectly through broader societal conditions rather than through direct hazard impacts. Therefore, climate change is not expected to significantly influence the likelihood of terrorism or mass casualty incidents within Rancho Cucamonga during the planning period.
Transportation Accident
Climate change may indirectly influence transportation accident risks within Rancho Cucamonga. More frequent extreme heat events may affect roadway surfaces, transportation infrastructure, vehicle performance, and driver safety. Severe weather events, including intense precipitation, flooding, debris flows, and reduced visibility, may increase the risk of vehicle collisions and transportation disruptions. Wildfires and associated smoke conditions may also affect visibility along roadways and transportation corridors, while emergency evacuations may increase traffic volumes and congestion during hazard events.
Although climate change is not expected to directly cause transportation accidents, changing environmental conditions may increase the likelihood of transportation disruptions and contribute to conditions that elevate accident risk. As a result, transportation systems may experience increased operational challenges during extreme weather and climate-related hazard events.
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HAZARD PROFILE: HAZARDOUS MATERIALS
RELEASE
Description
Hazardous materials release refers to a hazardous event in which harmful concentrations of hazardous or toxic substances are released into the environment, typically when storage containers leak or fail. It can result from industrial accidents, vehicle crashes, disasters (e.g., floods or earthquakes), or deliberate acts.
The threat that hazardous materials pose to human health depends on the type of material, frequency, and duration of exposure, and whether chemicals are inhaled, penetrate the skin, or are ingested, among other factors. Exposure to hazardous materials can result in short- or long-term effects, including major damage to organs and systems in the body or death. Hazardous waste is any material with properties that make it dangerous or potentially harmful to human health or the environment.
Hazardous materials can also cause health risks if they contaminate soil, groundwater, and air, potentially posing a threat long after the initial release.
Environmental justice considerations are also relevant to hazardous materials planning.
Certain communities may experience disproportionate exposure to pollution sources or environmental contaminants. To evaluate these conditions, this analysis incorporates information from CalEnviroScreen, a statewide screening tool developed by the California Environmental Protection Agency (CalEPA) that identifies communities disproportionately burdened by pollution and environmental health risks.45 This dataset helps identify California communities most affected by many pollution sources and where people are often especially vulnerable to pollution’s effects. The dataset uses environmental, health, and socioeconomic information to produce scores for every census tract in the state, mapped on a scale based on each location's pollution burden.
The higher the percentage, the greater the burden, and the higher the likelihood of environmental justice concerns.
Location and Extent
Hazardous materials and chemicals are used daily in households and businesses throughout Rancho Cucamonga. In addition to large industrial sites, sources of hazardous materials can come from seemingly harmless places such as service stations, dry cleaners, medical centers, and almost any industrial business. Hazardous waste can take the form of liquids, solids, contained gases, or sludge, and can be by45 California Office of Environmental Health Hazard Assessment. 2018. CalEnviroScreen 3.0 (updated June 2018). https://oehha.ca.gov/calenviroscreen/report/calenviroscreen-30
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products of manufacturing processes or simply discarded commercial products, such as cleaning fluids and pesticides. Figure 3-14 identifies the locations of hazardous material facilities within the City registered in the EPA’s Facility Registry Service (FRS).
In addition to fixed facilities, hazardous materials are routinely transported through Rancho Cucamonga via Interstate 10, Interstate 15, State Route 210, rail corridors, and local arterial roadways. Transportation-related incidents involving fuel, chemicals, compressed gases, or other hazardous substances have the potential to affect areas beyond the immediate release location through fires, explosions, spills, vapor clouds, or environmental contamination
The FRS is a centrally managed database that identifies facilities, sites, or places subject to environmental regulations or of environmental interest. These facilities include anything from grocery stores to gas stations. These locations have been overlaid on the CalEnviroScreen dataset, which identifies California communities by census tracts that are disproportionately burdened by and vulnerable to multiple pollution sources.
In difficult situations, Rancho Cucamonga may also be at risk of hazardous materials release events regionally. With the right prevailing wind conditions, airborne toxic material could spread to and impact various parts of the air basin, including the Rancho Cucamonga area.
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Figure 3-14. Hazardous Materials Locations
.
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Past Events
Rancho Cucamonga experiences periodic hazardous materials releases associated with transportation activities, utility infrastructure, commercial operations, sewage spills, and petroleum products. Based on Cal OES Spill Release Reporting records, the City experienced between 9 and 27 reported releases annually from 2010 to 2024, averaging approximately 16 incidents per year. The highest number of reported releases occurred in 2012 (27 incidents), while the lowest occurred in 2015 (9 incidents). More recent reporting indicates that hazardous materials releases continue to occur regularly, although most incidents are relatively small in scale and are contained before causing significant impacts on public health or the environment. Table 3-18 summarizes reported hazardous materials releases within Rancho Cucamonga from 2010 through 2025.
TABLE 3-18. RANCHO CUCAMONGA SPILL RELEASE REPORTING
Year Reported Releases Year Reported Releases
2010 14 2018 17
2011 15 2019 19
2012 27 2020 17
2013 20 2021 21
2014 18 2022 10
2015 9 2023 17
2016 10 2024 12
2017 21 2025 10
Source: California Governor's Office of Emergency Services (Cal OES) Spill Release Reporting Database (2010–2025). https://www.caloes.ca.gov/cal-oes-divisions/fire-rescue/hazardous-materials/spill-releasereporting Since the adoption of the 2021 LHMP, Rancho Cucamonga has continued to experience periodic hazardous materials releases associated with transportation incidents, sewage spills, petroleum products, utility operations, and commercial activities. Although most incidents were relatively minor and contained before causing significant impacts, hazardous materials releases continue to occur regularly within the City. The persistence of these incidents demonstrates that hazardous materials releases remain an ongoing operational and environmental risk requiring continued preparedness, response coordination, and regulatory oversight.
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Risk of Future Events
Most hazardous materials releases in Rancho Cucamonga result from human error, equipment failures, transportation incidents, utility operations, or accidental spills. Given the routine use, storage, and transportation of hazardous materials throughout the City, future release events are expected. Based on historical reporting trends, Rancho Cucamonga experiences an average of approximately 16 hazardous materials releases annually, or more than one reported incident per month. While most incidents are minor and quickly contained, larger releases can affect public health, critical infrastructure, transportation systems, environmental resources, and nearby communities.
Climate Change Considerations
Climate change may indirectly increase HAZMAT release risks by increasing the frequency and severity of certain natural hazards. Flooding, severe storms, wildfires, extreme heat, and power outages may damage storage facilities, transportation infrastructure, pipelines, or equipment used to store and transport hazardous materials.
Extreme precipitation may increase the potential for contaminated runoff, while extreme heat may affect the storage, stability, and combustibility of certain materials. Although climate change is not expected to directly cause hazardous materials releases, changing environmental conditions may increase the likelihood or consequences of future incidents.
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HAZARD PROFILE: AIRCRAFT INCIDENT
Description
An aircraft incident refers to an airborne vehicle—such as an airplane, helicopter, or airship — that experiences a failure to the extent that people aboard the vehicle or on the ground are endangered. This could result from human error, inclement weather, deferred maintenance, a design flaw, equipment failure, or, in a worst-case scenario, a collision.
Location and Extent
Rancho Cucamonga has no airports within its city boundaries. However, there are two airports located in the adjacent cities of Ontario and Upland. 1) Ontario International Airport is located approximately 3.2 miles southwest of Rancho Cucamonga’s City Hall. It is a major international airport in Southern California and the home to major shipping facilities for the United Parcel Service (UPS) and Federal Express (FedEx).
2) Cable Airport is located approximately 4.5 miles west of the residential areas in the Alta Loma area of Rancho Cucamonga. It is a small regional airport in the City of Upland that houses many privately owned and operated aircraft.
To better understand the differences between an aircraft accident and an aircraft incident, based on Title 49 of the Code of Federal Regulations Part 830 (§830.2):
An accident is an occurrence associated with the operation of an aircraft that:
• Occurs between the first boarding person entering the aircraft with the intention of flight and the last person disembarking;
• Results in death or serious injury; or
• Causes substantial damage to the aircraft.
An incident is an occurrence—other than an accident (no intention of flight)—associated with the operation of an aircraft that affects or could affect the safety of operations.
Past Events
Given Rancho Cucamonga's proximity to both Cable Airport and Ontario International Airport, aircraft incidents remain a potential hazard within the City and the surrounding region. Although aircraft accidents are infrequent, incidents have occurred within and
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near Rancho Cucamonga, demonstrating that the hazard remains a potential risk to people, property, and infrastructure.
TABLE 3-19. AIRCRAFT ACCIDENT STATISTICS (1962–2025)
Airport
Total
Events
Events Involving
Fatalities
Ontario International Airport 19 2
Cable Airport 17 5
Source: National Transportation Safety Board (NTSB) Aviation Investigation Search. https://www.ntsb.gov/Pages/AviationQueryv2.aspx
Accidents near Rancho Cucamonga include the following:
• 4/18/2023: An aircraft lost engine power, causing a collision with the airport boundary fence during a forced landing.
• 8/18/2020: An aircraft suffered damage after landing and taxiing when its landing gear collapsed, and the right wing struck the runway. • 11/07/2019: A small plane crashed into a private residence in Upland as the pilot attempted to return to Cable Airport. The pilot was killed on impact; the father and infant son within the residence escaped unharmed.46 • 06/15/2019: A small plane carrying a pilot and two passengers crash-landed in Upland on the 1300 block of N. Benson around 9:45 a.m. All three sustained severe injuries and were transported to the hospital.47 • 12/31/1994: Small Cessna model aircraft crashes into the mountainous terrain about 7 miles north of Rancho Cucamonga, resulting in the pilot's death and destroying the plane. The wreckage was not discovered for almost 10 months.48
Major accidents in Rancho Cucamonga include the following:
• 07/18/2014: A small plane with only the pilot aboard crashed near the north end of Haven Avenue, injuring the pilot.49
46 Kurzweil, A., Von Quednow, C., & McGraw, J. 2019. NTSB Helping Investigate Deadly Plane Crash Into Upland Home; Pilot Still Unidentified. KTLA 5. https://ktla.com/news/local-news/ntsb-to-investigate-deadly-plane-crashinto-upland-home-pilot-still-unidentified/ 47 Eyewitness News. 2019. 3 Injured in plane crash near Cable Airport in Upland. ABC 7. https://abc7.com/3- injured-in-plane-crash-near-cable-airport-in-upland/5348196/ 48 Idoni, J. 2013. San Gabriel Mountains Cessna 182B N2569G 9/15/13. https://joeidoni.smugmug.com/AircraftCrash-Sites/9D/ 49 Cappis, G. 2014. Small plane crashes in Rancho Cucamonga field; pilot Injured. Daily Bulletin. https://www.dailybulletin.com/2014/07/18/small-plane-crashes-in-rancho-cucamonga-field-pilot-injured/
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• 01/25/2003: A light plane crashed into a house in Rancho Cucamonga, killing the pilot and narrowly missing a 17-year-old boy watching television.50 • 03/28/1986: A small Beech model aircraft crashed, resulting in the pilot and passenger deaths and destroying the plane.
Since the adoption of the 2021 LHMP, several aircraft incidents have occurred at or near Cable Airport and Ontario International Airport. Most incidents involved mechanical failures, landing accidents, or operational issues and resulted in localized impacts.
Although aircraft incidents remain relatively infrequent, recent events demonstrate the continued presence of aviation-related risk within the Rancho Cucamonga area.
Risk of Future Events
Given the high volume of air traffic in the area, the possibility of an aircraft accident in Rancho Cucamonga will persist. Based on historical events, future impacts are anticipated to be similar. A key component of aircraft safety is the administration of the Airport Environs Land Use Plan for Ontario International Airport. This plan identifies the height restrictions and safety zones that require land-use restrictions to minimize potential impacts. Future land-use decisions that adhere to these restrictions and are planned accordingly will help reduce future impacts associated with aircraft accidents.
While these efforts can help reduce impacts on the ground, little can be done to reduce the impacts associated with aircraft flying overhead under normal flight conditions. The risk associated with this is like that of other parts of San Bernardino County and Southern California. Future growth in passenger travel, air cargo operations, and general aviation activity throughout the region may contribute to continued exposure to aircraft incidents in Rancho Cucamonga and neighboring communities.
Climate Change Considerations
Climate change is not expected to directly increase the likelihood of aircraft incidents.
However, extreme heat may affect aircraft performance, while severe weather, wildfire smoke, and reduced visibility may pose operational challenges for aviation. Overall, climate change is expected to have a limited indirect influence on the risk of aircraft incidents in Rancho Cucamonga.
50 Sahagun, L. 2003. Pilot Dies When Plane Plunges into House. LA Times. https://www.latimes.com/archives/laxpm-2003-jan-25-me-plane25-story.html
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HAZARD PROFILE: POWER FAILURE OR
ENERGY SHORTAGE
Description
Power Failure / Energy Shortage refers to the interruption, loss, or insufficient availability of electrical power resulting from infrastructure failures, severe weather, wildfires, earthquakes, cyber incidents, PSPS operations, transmission system disruptions, or regional energy supply constraints. Reliable electrical service is essential for the operation of homes, businesses, communications systems, transportation infrastructure, water and wastewater facilities, healthcare facilities, and emergency services. Prolonged outages or energy shortages can disrupt critical services, economic activity, public safety operations, and quality of life throughout the community.
Power failures and energy shortages may occur as standalone incidents or as secondary impacts resulting from natural hazards, technological failures, or humancaused events. Because modern infrastructure systems are highly interconnected, disruptions to electrical service may also affect communications, transportation, water systems, wastewater systems, healthcare operations, and emergency response capabilities.
Location and Extent
Power failures and energy shortages can occur throughout Rancho Cucamonga and may affect individual facilities, neighborhoods, large portions of the City, or the broader Southern California region depending on the nature of the disruption. The extent of an outage depends on the cause of the disruption and may range from localized service interruptions affecting individual neighborhoods to widespread outages affecting large portions of the City and surrounding region. Potential causes include severe wind events, wildfires, PSPS operations, earthquakes, utility equipment failures, cyber incidents, transmission system disruptions, and regional energy supply constraints.
The severity of a power failure or energy shortage is generally measured by the number of customers affected, the duration of the outage, and the extent of disruption to critical infrastructure and essential services. Electrical service is necessary for the operation of communications systems, traffic signals, water and wastewater facilities, healthcare facilities, fuel stations, businesses, schools, and public safety operations. Prolonged outages may result in cascading impacts on other infrastructure systems and essential community services. Power disruptions can also affect the operation of water and wastewater systems, demonstrating the interdependence of critical infrastructure networks.
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Critical facilities, including emergency response facilities, healthcare facilities, communications infrastructure, water supply facilities, and wastewater treatment systems, may be particularly vulnerable to prolonged outages if backup power systems are unavailable or unable to operate throughout the event. Because Rancho Cucamonga relies on interconnected regional electrical transmission and distribution systems, outages originating outside City boundaries may also affect residents, businesses, and critical facilities within the City. Power failures and energy shortages may occur independently or as secondary impacts associated with other natural and human-caused hazards.
Past Events
Rancho Cucamonga has experienced power outages associated with severe wind events, utility equipment failures, wildfire mitigation activities, and regional electrical grid disruptions. During the October 2020 Santa Ana wind event, Southern California Edison implemented a PSPS affecting more than 1,000 customers in the City for up to 24 hours.
Additional PSPS operations have occurred throughout Southern California during periods of elevated wildfire risk.
More recently, California's electrical grid has experienced periods of elevated demand during extreme heat events, prompting statewide conservation alerts and concerns about grid reliability. Although widespread rolling blackouts have been uncommon in recent years, these events demonstrate the continued vulnerability of the electrical system to extreme weather conditions, equipment failures, and increasing demand.
Rancho Cucamonga has also experienced localized outages due to vehicle collisions, utility equipment failures, scheduled maintenance, and storm-related impacts. While most outages are short-lived, prolonged disruptions can affect residents, businesses, transportation systems, communications networks, and critical facilities throughout the City.
Risk of Future Events
Future power failures and energy shortages are expected to remain possible within Rancho Cucamonga. Electrical service disruptions may result from severe wind events, wildfires, earthquakes, extreme heat, cyber incidents, utility equipment failures, or regional transmission system disruptions. Increased reliance on electricity for residential, commercial, transportation, and public service functions may amplify the consequences of future outages. As a result, power failure is considered a recurring hazard that can affect residents, businesses, and critical infrastructure throughout the City.
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Increased electrification of buildings, vehicles, and infrastructure, combined with population growth and increasing electricity demand during extreme heat events, may contribute to future energy supply and reliability challenges.
Over the next five years, Rancho Cucamonga is expected to remain vulnerable to both localized outages and broader regional power disruptions. Continued maintenance of electrical infrastructure, emergency preparedness efforts, backup power capabilities, and coordination with utility providers will remain important to reducing future impacts of power failures and energy shortages.
Climate Change Considerations
Climate change may increase both the frequency and consequences of power failures and energy shortages within Rancho Cucamonga. More frequent and intense extreme heat events are expected to increase electricity demand, particularly during summer months when cooling needs are greatest. At the same time, increasing wildfire risk, severe wind events, and other climate-related hazards may increase the likelihood of utility disruptions and PSPS operations. These factors could place additional strain on electrical infrastructure and regional energy supplies during the planning horizon.
Increasing electrification of buildings, transportation systems, and community infrastructure may further strain the electrical grid during periods of extreme heat and peak energy usage.
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CHAPTER 4 –
THREAT AND VULNERABILITY
Each of the hazards discussed in Chapter 3 can have varying effects on different populations and community assets in Rancho Cucamonga. For example, while an extreme heat event will be equally severe across all of the City, some people may be harmed more than others. This chapter analyzes how various hazard conditions may affect Rancho Cucamonga and identifies the populations, critical facilities, and community assets that may face elevated levels of risk.
THREAT ASSESSMENT PROCESS
The threat assessment process examines the harm a hazard may cause to three groups: critical facilities, vulnerable populations, and other community assets (e.g., noncritical facilities, key services).
Critical Facilities
Critical Facilities (CFs) are properties and structures that play important roles in government operations and in the delivery of services to the community. Examples of CFs include local government offices and yards, community centers, public safety buildings such as police and fire stations, schools, and any other properties a city has deemed essential to its operations. Critical Facilities may also serve dual roles if a city designates them as public assembly points during an emergency. The City often owns CFs, but many are also privately owned and operated, such as certain utilities and telecommunications infrastructure.
The Hazard Mitigation Planning Committee identified 239 CFs in Rancho Cucamonga that fall into seven categories based on their function or characteristics. Table 4-1 shows the number of CFs in each category, the total estimated value of facilities, and examples of facilities in each category. Figure 4-1 shows the locations of some of the CFs in Rancho Cucamonga that were mapped. Some facilities were not mapped due to security concerns.
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Figure 4-1. Critical Facilities
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TABLE 4-1. CRITICAL FACILITIES REPLACEMENT COST
Category
Facility
Count Examples
Replacement
Cost
Bridge** 178** Overpasses and underpasses within the city $534,000,000 City Facility 14 City Hall, Operations Support $261,682,024 Fire Facility 9 Fire Stations and Sub Stations $76,861,318 Parks 33 Parks, Recreational Facilities, Sports
Complexes, and support facilities.
$1,438,228
Police Facility 3 Police Stations, Substations $41,507,449 Other Facility 2 Etiwanda Substation, CVWD Water Treatment Plant
$1,553,031
All Facilities Total 239 Critical Facilities $917,042,050 * Replacement cost based on an estimate of 3 million per bridge ** Not all bridges are the financial responsibility of the City; however, the City is responsible for reporting issues with non-City-owned bridges; therefore, it is included in these totals for tracking purposes.
The potential loss is the total insured value of the CFs within the hazard zone. It is intended to provide a ballpark estimate of replacement cost if the property is entirely or severely damaged. The actual repair costs could be higher or lower than the estimate provided. The City’s Property Schedule provided the data; information for facilities not owned by the City is not shown (e.g., bridges, private buildings). In some instances, replacement cost information was not made available.
Based on the City’s available data, there are at least $917,042,050 in City-owned assets. The total potential loss for all City-owned and non-City-owned assets is much higher but unknown due to data limitations. The greatest potential for loss among the City-owned assets comes from the Bridge category. The next category with the greatest potential for loss is City Facility. To better understand the magnitude of impacts, this plan identifies representative percentages of potential impact based on the City’s total asset valuation. For planning purposes, we identified different tiers of potential impact.
It is reasonable to assume that impacts would not exceed 50% of the citywide total asset value. The following values provide context regarding the relative magnitude of potential losses or mitigation investments compared to the City’s inventoried assets:
• 1% Impact – $9,170,421
• 5% Impact – $45,852,103
• 10% Impact – $91,704,205
• 20% Impact – $183,408,410
• 50% Impact – $458,521,025
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The likelihood that all facilities are completely damaged at the same time is extremely remote. Most impacts are anticipated to be isolated to certain locations based on the hazard. This estimate does not include the value of underground infrastructure and surface drainage facilities owned and operated by the City.
Vulnerable Populations
Factors such as age, physical and/or mental condition, socioeconomic status, access to key services, and many other factors affect people’s ability to prepare for and protect themselves and their property from a hazard event. Even though some hazard events may affect all parts of Rancho Cucamonga with equal severity, different people may experience them differently. For instance, higher-income households are more likely than lower-income households to retrofit their homes to resist flooding or move to a location less prone to flooding. As a result, the higher-income household is less likely to experience significant effects during a flood event than the lower-income household, even if the same amount of rain falls on both.
A social threat analysis examines how hazard events are likely to impact different demographic populations in Rancho Cucamonga and where they live in the City. This analysis assesses whether people in an area with elevated hazard risk are more likely than the average person to be considered a threatened population. The social threat analysis uses the following criteria to assess the threat to vulnerable populations:
• Disability status: Persons with disabilities may experience mobility, communication, cognitive, sensory, or other functional limitations. As a result, they may have little or no ability to prepare for and mitigate hazard conditions without others’ assistance.
• Income levels: Lower-income households may have fewer financial resources available to prepare for, mitigate, respond to, and recover from hazard events.
These households may face challenges implementing mitigation measures, obtaining insurance, accessing transportation, or relocating from hazard-prone areas. Financial constraints may also limit access to preparedness information, emergency supplies, and post-disaster recovery resources. As a result, lowerincome populations may experience disproportionately greater impacts from hazard events and may require additional support during disaster recovery efforts. See Table 4-2 for household income data.
• Seniors (individuals at least 65 years of age): Some older adults may experience reduced mobility, chronic health conditions, or fixed incomes that may affect their ability to prepare for, respond to, and recover from hazard events.
• English-language proficiency: Individuals with limited English proficiency will be present when the community faces a hazard event. These individuals have difficulty understanding, speaking, reading, or writing English. Consequences
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can be deadly if these individuals cannot access hazard information in their primary language.
• Persons Experiencing Homelessness: The San Bernardino County Point-inTime (PIT) Count provides an annual snapshot of sheltered and unsheltered persons experiencing homelessness. People experiencing homelessness may be disproportionately vulnerable during hazard events due to limited access to shelter, transportation, communications, healthcare, and recovery resources.
They may also have limited access to emergency notifications, climatecontrolled shelter, and other services needed during emergencies. As a result, people experiencing homelessness are considered an access and functional needs population for emergency planning and hazard mitigation purposes. Due to the limited amount of data available, this population is unable to be analyzed in a similar manner to the other data listed above.
Table 4-2 presents metrics for the City of Rancho Cucamonga for threatened or vulnerable populations. For broader demographic information regarding the City, please refer to Chapter 2.
TABLE 4-2. THREATENED POPULATION METRICS
Threatened Population Metric
Rancho
Cucamonga
Total Population 174,772
Total Households 57,984
Median household income $112,514
Renter Households 39.8%
Percentage of households with at least one person living with a disability 22.5% Percentage of households living below the poverty limit 8.6% Percentage of households with at least 1 person aged 65+ 29.5% Area Affected by Hazard (Square mile) 46.51 sq miles
Sources: Esri Community Analyst 2024 Estimates (population, households, median household income, renter households); U.S. Census Bureau ACS 2019–2023 5-Year Estimates (disability status, poverty status, and age 65+ population).
Note: ACS 2024 estimates were used where available; otherwise, ACS 2019-2023 five-year estimates were utilized.
Table 4-2 summarizes the citywide demographic metrics used throughout the risk assessment to evaluate the social vulnerability of populations that may be affected by natural and human-caused hazards. The table includes total population, households, median household income, renter households, disability status, poverty, and households with one member aged 65 years or older. These demographic indicators provide a consistent citywide baseline for comparing the characteristics of populations located within individual hazard areas discussed throughout this chapter.
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Data Limitations and Notes on Vulnerability Tables
Due to data limitations, the data comparing the hazard zone population with the Citywide population comes from two separate sources. The Citywide data comes from the US Census Bureau’s American Community Survey (ACS). The hazard zone population data comes from ESRI’s Business Analyst reports, which rely on ESRI and ACS data estimates. As a result, there may be minor discrepancies in comparing the two data sets. The data to rely on when addressing demographics for the entire community is the ACS data reported in Chapter 2.
Data Disclaimer: Demographics and Economic Variables
To assess a community’s vulnerability to hazards, Esri’s Business Analyst is used to calculate the value or percentage of specific socio-economic or socio-demographic characteristics for a defined hazard area. Use of this software enables consistent, comparable analyses of key socio-economic or socio-demographic variables by hazard area (e.g., the number of households within a liquefaction area).
Esri provides Updated Demographics releases each summer based on decennial U.S.
Census data and/or the U.S.ACS 5-year estimates. Esri then combines key data from other public sources (e.g., the Bureau of Labor Statistics and the Bureau of Economic Analysis) and private data sources (e.g., Experian, Zonda, and RealPage) to provide estimates and forecasts of demographic and economic metrics. As a result, Esri Updated Demographics’ output may not align exactly to the corresponding socioeconomic or socio-demographic variables found on the U.S. Census Bureau’s data portal.
Other Assets
In addition to the City’s designated inventory of CFs and vulnerable populations, hazard events could threaten other important assets to Rancho Cucamonga. These assets may include services, artistic or cultural landmarks, or local economic activities. The threat assessment describes the potential harm to these other assets based on available information.
DISASTER DECLARATION CONNECTIONS
FEMA has issued several major disaster declarations, emergency declarations, and Fire Management Assistance Grants affecting San Bernardino County since 2020 (Table 4- 3). While most of these incidents did not directly impact the City or require activation of the City's Emergency Operations Center (EOC), the COVID-19 pandemic directly affected the City and necessitated the activation of emergency management functions.
In addition, City staff participated in regional coordination activities, including Regional
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EOC meetings and WebEOC information sharing, during several countywide and regional incidents. Past events identified in this Plan are discussed in the hazardspecific profiles in Chapter 3.
TABLE 4-3. FEMA-RELATED DISASTER DECLARATIONS IN
SAN BERNARDINO COUNTY (2021–2026)
Year
Declaration
Number Declaration Title
Incident
Type
Direct
Impact to
RC
2025 FM-5549-CA* Palisades Fire Fire Yes
2024 FM-5537-CA Bridge Fire Fire No
2024 FM-5535-CA Line Fire Fire No
2024 DR-4769-CA
California Severe Winter Storms,
Tornadoes, Flooding, Landslides, and
Mudslides
Severe Storm No
2023 DR-4699-CA Severe Winter Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides Severe Storm No
2023 EM-3591-CA Severe Winter Storms, Flooding, and
Mudslides Flood No
2023 EM-3592-CA Severe Winter Storms, Flooding, Landslides, and Mudslides Flood No
2023 DR-4683-CA California Severe Winter Storms, Flooding, Landslides, and Mudslides Multiple UNK
2020 DR-4569-CA California Wildfires Fire No
2020 FM-5381-CA California Blue Ridge Fire Fire No
2020 DR-4482-CA COVID-19 Pandemic Biological Yes
2020 EM-3428-CA COVID-19 Biological Yes
2020 FM-5350-CA El Dorado Fire Fire No
2020 FM-5325-CA Apple Fire Fire No
2020 FM-5301-CA Hillside Fire Fire No
DR = Major Disaster | EM = Emergency Declaration | FM = Fire Management Assistance Grant *This table summarizes FEMA disaster declarations and other significant disaster declarations that affected San Bernardino County between 2020 and 2026. In some cases, a declaration may be included because the City experienced impacts and received assistance through the California Disaster Assistance Act (CDAA), even if the City was not located within the designated FEMA assistance area.
Since 2020, disaster declarations affecting San Bernardino County have primarily been associated with wildfire, severe winter storms, flooding, and the COVID-19 pandemic.
The frequency of declarations related to severe weather and wildfire highlights the ongoing exposure of Southern California communities to climate-related hazards and underscores the importance of maintaining preparedness, coordination, and mitigation capabilities throughout Rancho Cucamonga.
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THREAT PROFILE: SEISMIC HAZARDS
Physical Threat and Vulnerability
Seismic Shaking
Seismic shaking from an earthquake has the greatest potential to cause injuries and loss of life, as well as property and economic damage within the City. As part of the San Bernardino County Multi-Jurisdictional Hazard Mitigation Plan (MJHMP) update, a Hazus estimate was prepared for the City.51
Many physical assets in the City are estimated to experience the same seismic shaking intensity, ranging from 95% to 125% g (g is the acceleration due to gravity). Therefore, all facilities could be damaged during a significant seismic event, which would likely be extremely costly for the City. Although simultaneous damage to all facilities is unlikely, a significant earthquake could cause substantial losses to public infrastructure, critical facilities, businesses, and residential development throughout the City. Potential impacts include structural damage, utility disruptions, transportation interruptions, debris generation, economic losses, and prolonged recovery efforts. Consistent with the San Bernardino County MJHMP methodology, seismic hazards are among the highestconsequence hazards facing the City due to the potential for widespread impacts on the population, critical facilities, lifelines, and built infrastructure. Underground infrastructure, such as pipelines and utilities, could be damaged if shaking intensity is high enough to affect these assets. In such a scenario, natural gas and water delivery service to Rancho Cucamonga homes and businesses would be out of commission until repairs are completed.
Fault Rupture
The City has several active faults located within special study zones (both Alquist-Priolo and City-defined) that have been mapped along the foothills of the San Gabriel Mountains. To better understand the potential risks associated with surface fault rupture, properties located within these zones were identified and analyzed. Approximately 791 parcels are located within mapped special study zones in the City and its Sphere of Influence. While development within these special study zones adheres to regulations developed by the State, existing development, infrastructure, and future development opportunities remain present within these areas. Consequently, a significant surface fault rupture could damage existing structures, infrastructure, and other improvements located within or adjacent to these fault zones.
51 Hazus is a nationally standardized risk modeling methodology.
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In addition to the properties potentially impacted by fault rupture, Table 4-4 identifies the CFs located within the special study zones identified for the Cucamonga, Etiwanda, and Red Hill Faults. Based on this analysis, the City has approximately $31 million in assets located near these faults.
TABLE 4-4. CRITICAL FACILITIES (FAULT RUPTURE)
Category
Number of
Facilities
(AP Zones)
Total
Replacement
Costs**
Number of
Facilities (Red
Hill Fault Zone)
Total
Replacement
Costs**
Bridge 1 $3,000,000 14 $42,000,000
City Facility 0 $0 1 $15,516,010
Fire Facility 0 $0 1 $7,998,193
Parks 0 $0 3 N/A
Police Facility 0 $0 0 N/A
Other Facilities 0 $0 0 N/A
Total 1 $3,000,000 19 $65,514,203
* Replacement cost based on an estimate of 3 million per bridge ** Based on the City of Rancho Cucamonga insured replacement values Liquefaction
Although liquefaction susceptibility is limited geographically, damage to affected facilities and infrastructure could result in localized service disruptions. Four CFs are located within the Liquefaction hazard zone, potentially exposing over $5 million in assets (Table 4-5).
TABLE 4-5. CRITICAL FACILITIES (LIQUEFACTION)
Category Number of Facilities Total Replacement Costs** Bridge 0 $0
City Facility 2 $5,610,540
Fire Facility 0 $0
Parks 2 N/A
Police Facility 0 $0
Other Facilities 0 N/A
Total 4 $5,610,540
N/A = Replacement values unavailable
** Based on the City of Rancho Cucamonga insured replacement values
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Earthquake-Induced Landslide
As with liquefaction, there are no known records of earthquake-induced landslides within the City. The areas of potential are primarily located in the foothills and mountainous portions of the Sphere of Influence. Although no critical facilities are located within these hazard zones, future seismic events could affect transportation routes, utilities, drainage facilities, and undeveloped lands located within susceptible areas.
Deep-Seated Landslide
In addition to EQ-I Landslide hazards, the City also identified potential losses associated with deep-seated landslides (Table 4-6).
TABLE 4-6. CRITICAL FACILITIES (DEEP-SEATED LANDSLIDE)
Category Number of Facilities Total Replacement Costs** Bridge 31 $93,000,000
City Facility 0 $0
Fire Facility 4 $34,715,375
Parks 5 N/A
Police Facility 0 $0
Other Facility 1 N/A
Total 41 $127,715,375
N/A = Replacement values unavailable
** Based on the City of Rancho Cucamonga insured replacement values Social Threat
The risk of a seismic event is a danger to all groups in Rancho Cucamonga, though some are more threatened than others.
Seismic Shaking
Seniors, pregnant women, and persons with disabilities are more threatened by seismic shaking since they may have limited mobility and cannot reach shelter in time. Even if these groups reach shelter in time, they may find themselves trapped if furniture or building components have fallen around them. Renters and low-income persons are also more vulnerable to seismic shaking, as these groups may live in homes that are not properly retrofitted to withstand the stresses of a seismic event. These groups may not be able to cover the costs of repairing their homes or finding new housing if their
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existing homes are too damaged to occupy. In terms of geography, the effects of seismic shaking on vulnerable populations are anticipated to be reduced in higher-elevation areas, which tend to have lower population densities and higher household incomes.
Table 4-7 compares the areas within the City subjected to seismic shaking below and above 1g.52 As part of this comparison, the data indicate that areas subjected to lower seismic shaking also have lower median household incomes and higher percentages of persons living with disabilities, of households living below the poverty line, and of persons aged 65+ living alone.
TABLE 4-7. SEISMIC SHAKING THREATENED POPULATIONS
Threatened Population Metric
Seismic Shaking
(>1.05g)*
City of Rancho
Cucamonga
Total Population 22,561 174,742
Total Households 6,324 57,984
Median household income $185,817 $112,514
Renter Households 11.1% 39.8%
Percentage of households with at least one person
living with a disability 19.2% 22.5%
Percentage of households living below the poverty
limit 3.4% 8.6%
Percentage of households with at least 1 person aged
65+ 29.8% 29.5%
Sources: Esri Community Analyst 2024 Estimates (population, households, median household income, renter households); U.S. Census Bureau ACS 2019–2023 5-Year Estimates (disability status, poverty status, and age 65+ population).
Note: ACS 2024 estimates were used where available; otherwise, ACS 2019-2023 five-year estimates were utilized.
Fault Rupture
To analyze the social threat associated with fault rupture, the City identified the populations located within the AP Zones mapped within the City. Table 4-8 identifies the characteristics of these areas, including higher median household incomes, higher percentages of persons living with a disability, and higher percentages of households with one member aged 65+.
52 At this level of shaking, the forces are strong enough to cause structural damage to buildings not specifically engineered to withstand major earthquakes. It often causes significant damage to non-structural elements and loose contents.
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TABLE 4-8. FAULT RUPTURE THREATENED POPULATIONS
Threatened Population Metric AP Zones
City of Rancho
Cucamonga
Total Population 592 174,772
Total Households 197 57,984
Median household income $151,211 $112,514
Renter Households 9.4% 39.8%
Percentage of households with at least one person living with a disability 26.9% 22.5%
Percentage of households living below the poverty limit 8.1% 8.6% Percentage of households with at least 1 person aged 65+ 39.6% 29.5% Sources: Esri Community Analyst 2024 Estimates (population, households, median household income, renter households); U.S. Census Bureau ACS 2019–2023 5-Year Estimates (disability status, poverty status, and age 65+ population).
Note: ACS 2024 estimates were used where available; otherwise, ACS 2019-2023 five-year estimates were utilized.
Liquefaction
Due to the limited geographic extent and relatively small population in liquefaction-prone areas, a detailed social vulnerability analysis was not conducted. However, residents, businesses, and facilities located within susceptible areas may experience localized impacts, including ground settlement, infrastructure damage, and service disruptions, following a major earthquake.
Earthquake-Induced Landslide
As secondary seismic hazards, both liquefaction and earthquake-induced landslides impact small areas of the City. Due to the small size of the liquefaction hazard zone and the sparse population within the EQ-I landslide zones, the social vulnerability analysis yielded unreliable results. It is estimated that these areas have small populations that could be impacted by these hazards and could be challenged if there is a higher proportion of residents with lower household incomes and high proportions living under the poverty limit or with a disability.
Deep-Seated Landslide
Landslide-prone properties are predominantly located in the northern portions of the City, in the San Gabriel Mountains foothills. Table 4-9 identifies the threatened populations within these areas. Based on this analysis, these areas have a higher proportion of households with persons living with a disability and households with one member aged 65+. While these indicators are higher, these areas have a significantly
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higher median household income than the City, which may allow households there to rebuild more easily after a disaster.
TABLE 4-9. LANDSLIDE THREATENED POPULATIONS
Threatened Population Metric
Landslide
Zones*
City of Rancho
Cucamonga
Total Population 43,580 174,772
Total Households 12,952 57,984
Median household income $122,338 $112,514
Renter Households 23% 39.8%
Percentage of households with at least one person living with a disability 4.7% 22.5%
Percentage of households living below the poverty limit 28.2% 8.6% Percentage of households with at least 1 person aged 65+ 3.7% 29.5% Sources: Esri Community Analyst 2024 Estimates (population, households, median household income, renter households); U.S. Census Bureau ACS 2019–2023 5-Year Estimates (disability status, poverty status, and age 65+ population).
Note: ACS 2024 estimates were used where available; otherwise, ACS 2019-2023 five-year estimates were utilized.
Other Threats
Major earthquakes may damage electrical transmission and distribution infrastructure, substations, underground utilities, and communications systems, resulting in prolonged power outages throughout the City and surrounding region. Power disruptions may affect emergency response operations, water and wastewater systems, healthcare facilities, transportation networks, and business operations. Restoration efforts may be delayed if transportation routes, communications systems, or utility infrastructure are damaged by the seismic event. Additional discussion regarding power outages and energy reliability is provided in the Power Failure or Energy Shortage hazard profile.
Seismic Shaking
As early earthquake warning systems become operational, utilities can be expected to use these warnings to shut off gas, water, and power transmission to control potential leaks following seismic shaking. Authorities may have enough time to halt bridge use or move workers to a safe distance from hazardous materials. Workers will cease their activity and take shelter until they can be safely evacuated. Therefore, all services will be non-operational during the seismic shaking and remain inactive until authorities are confident that it is safe to reactivate utilities and return employees to their workplaces.
The duration of this period would vary with the magnitude of the event. A significant
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earthquake would likely put utilities out of commission and halt any employment activity in the City for a few hours or several days. The City and the region would lose economic activity that would normally occur during the outage period. Like telephone poles or power transmission towers, structures that have fallen due to the shaking could potentially block roadways and prevent emergency response personnel from reaching victims or evacuees who need assistance. As with fault rupture, seismic shaking could also affect flooding and dam inundation zones.
Fault Rupture
Seismic events that cause surface fault rupture tend to damage roads and structures in the affected areas. The length of rupture is typically a component of the magnitude of the seismic event. The stronger the event, the greater the distance that rupture can occur. Strong events can exacerbate problems with other identified hazards, such as dam inundation and flooding.
Liquefaction
Services and mobility may be disrupted during and following a seismic event. As liquefaction typically occurs in isolated areas of the City, the effects there may include damage to roadways, infrastructure (power poles and underground pipelines), and storm management infrastructure. This damage could result in loss of utility services or inability to access areas of the City.
Earthquake-Induced Landslide
Services and mobility may be disrupted during and following a seismic event. As EQ-I landslides typically occur in isolated areas of the City, the effects there may include damage to roadways, infrastructure (power poles and underground pipelines), and storm management infrastructure. This damage could result in loss of utility services or inability to access areas of the City.
Deep-Seated Landslide
Areas prone to deep-seated landslide hazards may experience large movements of earth materials. If this occurs, any infrastructure built on or within these areas may be affected. Depending on the movement's size and scale, structures in these areas may become uninhabitable. If a large landslide were to occur, it could require significant mitigation to make the area safe for building structures. In addition, landslides tend to affect the environments they enter. These impacts could include the filling of streams and channels (which could exacerbate flooding), the filling of flood-control basins and drainage infrastructure, and the blocking of access to areas of the City for emergency
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response services if roadways become impassable. If a small-scale landslide were to occur, the effects could be minimal or cause very little damage to the community.
Changes in Population and Land Use Development
Seismic Shaking
Rancho Cucamonga is largely developed; however, future infill development, redevelopment, and continued growth within the Sphere of Influence may increase the number of people, structures, and community assets exposed to seismic shaking.
Further development of residential, commercial, industrial, and public infrastructure could increase the potential economic losses from future earthquakes. Although modern building codes are intended to improve seismic performance, future growth may increase the overall consequences of a major earthquake due to greater population and development concentration.
Fault Rupture
Future development in areas affected by the Cucamonga Fault, Etiwanda Avenue Fault, and the Red Hill-Etiwanda Fault system could increase the number and value of structures exposed to fault-rupture hazards. However, development within identified fault hazard areas is subject to geologic investigations, Alquist-Priolo Earthquake Fault Zoning Act requirements, California Building Code standards, and local development regulations intended to reduce vulnerability to fault rupture.
Liquefaction
Future development within areas susceptible to liquefaction could increase the number of people, structures, and infrastructure exposed to this secondary seismic hazard.
Although liquefaction-prone areas in Rancho Cucamonga are relatively limited in extent, additional residential, commercial, or public infrastructure development within these areas could increase potential losses associated with ground settlement, lateral spreading, utility damage, and structural impacts following a major earthquake. Sitespecific geotechnical investigations conducted during the development review process are intended to identify liquefaction hazards and recommend appropriate mitigation measures where necessary.
Earthquake-Induced Landslide
Future development within areas susceptible to liquefaction or earthquake-induced landslides could increase the number of people, structures, and infrastructure exposed to these secondary seismic hazards. Portions of the City with shallow groundwater, alluvial soils, steep slopes, or hillside terrain may experience increased exposure if
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additional development occurs in these areas. Site-specific geotechnical investigations conducted during the development review process are intended to identify these hazards and recommend appropriate mitigation measures where necessary.
Deep-Seated Landslide
Future development within areas susceptible to deep-seated landslides could increase the number and value of structures, infrastructure, and community assets exposed to slope instability hazards. Although many of the highest-susceptibility areas are currently located within the northern foothills and mountainous portions of the City and Sphere of Influence, continued development near these areas could increase future exposure.
Because deep-seated landslides can involve large volumes of earth material and affect broad areas, future development may increase the potential for damage to roadways, utilities, drainage facilities, residential neighborhoods, and other improvements located adjacent to unstable slopes. Geotechnical investigations, grading regulations, and hillside development standards will continue to play an important role in reducing future landslide-related risks.
Climate Change Vulnerability
Seismic Shaking
Current scientific research does not indicate a direct relationship between climate change and increased earthquake frequency or magnitude.53 As a result, climate change is not expected to significantly affect the occurrence, frequency, or intensity of seismic shaking hazards affecting Rancho Cucamonga. Future seismic risk is expected to remain primarily influenced by regional geologic and tectonic processes.
Fault Rupture
There is currently no established scientific evidence linking climate change to increased fault rupture activity.54 Although some studies have examined the potential influence of long-term changes in surface loading on tectonic systems, climate change is not expected to significantly affect the probability or severity of fault rupture hazards in Rancho Cucamonga.
53 USGS. (2023). Can large amount of rain in California cause an increase in earthquakes? https://www.usgs.gov/faqs/can-large-amounts-rain-california-cause-increase-earthquakes 54 Ibid.
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Liquefaction
Climate change may indirectly influence susceptibility to liquefaction through changes in precipitation patterns and groundwater conditions. More frequent periods of intense rainfall may temporarily increase groundwater levels in some portions of Rancho Cucamonga, potentially increasing liquefaction susceptibility where loose, saturated soils are present. Conversely, prolonged drought conditions and groundwater depletion may reduce groundwater levels in some areas, potentially reducing liquefaction susceptibility. Despite these potential changes, liquefaction remains dependent upon the occurrence of a significant seismic event and the presence of susceptible soil conditions.
Earthquake-Induced Landslide
Climate change may indirectly influence liquefaction and earthquake-induced landslide hazards through changes in precipitation patterns, groundwater conditions, wildfire activity, and soil stability. More frequent periods of intense rainfall may increase groundwater levels in some locations and contribute to slope instability, while prolonged drought and wildfire activity may reduce vegetation cover and increase susceptibility to erosion and landslides. Although these factors may affect local conditions, both liquefaction and earthquake-induced landslides remain dependent upon a triggering seismic event.
Deep-Seated Landslide
Climate change may indirectly increase the susceptibility of deep-seated landslides by altering precipitation patterns, groundwater conditions, wildfire frequency, and vegetation cover. More intense rainfall events may increase soil saturation and groundwater pressures within slopes, potentially reducing slope stability. In addition, increased wildfire activity may remove vegetation and root systems that help stabilize hillsides, increasing erosion and the potential for slope movement. While climate change is not expected to directly cause deep-seated landslides, changing environmental conditions may increase the likelihood or severity of future slope failures in susceptible areas of Rancho Cucamonga.
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THREAT PROFILE: WILDFIRE
Physical Threat and Vulnerability
The Rancho Cucamonga Fire Protection District has adopted the Very High Fire Hazard Severity Zone (VHFHSZ) pursuant to state law and local ordinance. The VHFHSZ identifies areas of the City with the highest wildfire hazard based on factors such as vegetation, topography, weather, and fire history. Table 4-10 identifies the critical facilities located within the VHFHSZ and the associated potential replacement value at risk. A total of 45 critical facilities are located within the VHFHSZ, representing approximately $129 million in known replacement value. Additional losses associated with parks and schools located within the VHFHSZ could also occur.
TABLE 4-10. CRITICAL FACILITIES (VHFHSZ)
Category Number of Facilities Total Replacement Costs** Bridge 38 $114,000,000
City Facility 0 $0
Fire Facility 3 $14,435,192
Parks 2 N/A
Police Facility 0 $0
Other Facility 2 $612,691
Total 45 $129,047,883
N/A = Replacement values unavailable
** Based on the City of Rancho Cucamonga insured replacement values Although the VHFHSZ identifies the areas of highest wildfire hazard, wildfire risks are not necessarily limited to these mapped areas. Wind-driven embers may travel well beyond the VHFHSZ and ignite structures in developed areas that would not otherwise be considered at high wildfire hazard. These conditions are commonly associated with the wildland-urban interface (WUI), where vegetation and development intermingle. Dry vegetation, prolonged drought, strong winds, and ignition sources such as damaged electrical equipment can all contribute to wildfire spread. These conditions also contribute to the implementation of California's PSPS program during periods of elevated fire weather.
Social Threat
Outside of the property owners directly impacted by a wildfire event, wildfires can also impact seniors and persons with disabilities. These groups may have limited mobility,
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be immunocompromised, and/or fail to receive notifications about current conditions and evacuation requirements. For example, a senior who lives alone may not be aware that a wildfire is burning near their residence, and they may have been ordered to evacuate if those notifications were sent in a manner that did not reach them. Persons with disabilities may require special mobility devices or caregiver assistance to go outside, which may not arrive as quickly as needed. Other groups with increased threat levels include people with lower incomes, renters, and the homeless. These groups may not have sufficient financial resources to rebuild their homes or find new ones after a fire.
Table 4-11 identifies the populations living within the VHFHSZ. Based on this analysis, households within the VHFHSZ have a median household income approximately $68,000 higher than the citywide average, a slightly higher percentage of households with one or more persons living with a disability, and a higher percentage of households with one member aged 65 years or older. In contrast, the VHFHSZ has a lower percentage of households living below the poverty limit than the citywide average.
Overall, these demographic characteristics suggest that households within the VHFHSZ may have greater economic resources to support preparedness and recovery; however, the higher proportion of older adults indicates that evacuation planning, emergency notifications, and access and functional needs should remain important considerations during wildfire events.
TABLE 4-11. POPULATIONS WITHIN THE VHFHSZ
Threatened Population Metric VHFHSZ
City of Rancho
Cucamonga
Total Population 15,738 174,772
Total Households 4,687 57,984
Median household income $180,932 $112,514
Renter Households 10.6% 39.8%
Percentage of households with at least one
person living with a disability 23.3% 22.5%
Percentage of households living below the
poverty limit 4.5% 8.6%
Percentage of households with at least 1 person
aged 65+ 34.5% 29.5%
Area Affected by Hazard (Square mile) 13.86 sq miles
[29.8%] 46.51 sq miles
Sources: Esri Community Analyst 2024 Estimates (population, households, median household income, renter households); U.S. Census Bureau ACS 2019–2023 5-Year Estimates (disability status, poverty status, and age 65+ population).
Note: ACS 2024 estimates were used where available; otherwise, ACS 2019-2023 five-year estimates were utilized.
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Other Threats
Other threats associated with wildfires may include loss of electricity (PSPS) due to power failures or other utility disruptions, evacuation of areas potentially under threat, or the health effects of wildfires near the City or throughout the region. Loss of utility services associated with wildfire or PSPS events can disproportionately affect vulnerable populations more severely if they rely on these services for medical needs (oxygen, dialysis, etc.) or to ensure adequate heating and cooling. Wildfire events generally occur when the weather is hot and dry. These weather conditions place a high demand on air conditioning, especially for those whose health is worsened by extreme heat. Under these conditions, the loss of power can place greater strain on vulnerable residents, especially those who cannot provide their own backup power or afford to relocate during the disruption. Additional discussion regarding power outages and energy reliability is provided in the Power Failure / Energy Shortage hazard profile.
The health effects associated with wildfires can also be very detrimental to a community.
As wildfires in California become larger and more intense, there is a greater potential for smoke production. Chronic exposure to particulates generated during a wildfire can cause health outcomes that range from eye and respiratory tract irritation to more serious disorders, including reduced lung function, bronchitis, exacerbation of asthma and heart failure, and premature death. Children, pregnant women, and the elderly are especially vulnerable to smoke exposure. Emissions from wildfires are known to increase hospital and clinic visits among those exposed to smoke. 55 A study of the 2003 wildfires in southern California concluded that wildfire-related PM(2.5) led to increased respiratory hospital admissions, especially asthma, suggesting that better preventive measures are required to reduce morbidity among vulnerable populations.56 With the expectation that wildfire incidents will increase in size and severity in the future, it will be important to understand how the City can assist residents with poor air quality during wildfires occurring throughout the region.
Changes in Population and Land Use Development
Rancho Cucamonga's continued growth, particularly within and adjacent to the VHFHSZ and other wildfire-prone foothill areas, may increase the number of people, structures, and critical infrastructure exposed to wildfire hazards. Future residential and commercial development near the foothills and open spaces could be impacted by wildfire events.
Current development standards, defensible space requirements, fuel modification zones, and wildfire-resistant construction requirements are intended to reduce vulnerability.
55 https://www.epa.gov/air-research/wildland-fire-research-health-effects-research 56 The relationship of respiratory and cardiovascular hospital admissions to the southern California wildfires of 2003. https://pubmed.ncbi.nlm.nih.gov/19017694/
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Climate Change Vulnerability
Climate change is expected to increase temperatures and lead to more frequent and prolonged droughts throughout Southern California.
57 These changes may
reduce fuel moisture, increase vegetation stress and mortality, extend the wildfire season, and increase the likelihood of large and damaging wildfires.
In addition, climate change may contribute to more frequent periods of extreme fire weather, including hot, dry, and windy conditions that can accelerate wildfire ignition and spread. Increased wildfire activity may also result in greater exposure to smoke, degraded air quality, post-fire erosion, debris flows, and impacts to critical infrastructure.
58 As a result, climate change is
expected to increase Rancho Cucamonga's overall vulnerability to wildfire hazards.
57 California Climate Adaptation Strategy. (2026). Summary of Projected Climate Change Impacts on California. https://climateresilience.ca.gov/overview/impacts.html
58 Center for Climate and Energy Solutions. (2021). Wildfires and Climate Change. https://www.c2es.org/content/wildfires-and-climate-change/
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THREAT PROFILE: FLOOD
Physical Threat and Vulnerability
Flooding
Portions of the City are located within the 100-year (1.0% Annual Chance of Flooding) and 500-year (0.2% Annual Chance of Flooding) flood zones. Physical assets located within mapped flood hazard areas may be vulnerable to inundation during flood events that exceed the capacity of local drainage and stormwater infrastructure. Electronic or mechanical equipment on the ground could become waterlogged and nonfunctional.
Table 4-12 identifies the City’s physical assets within the 100-year, 500-year, and 500- year flood zones.
TABLE 4-12. CRITICAL FACILITIES (100-YEAR FLOOD/500-YEAR FLOOD) Flood Risk Flooding (100-Year) Flooding (500-Year)
Bridge 72 6
City Facility 0 2
Fire Facility 0 2
Parks 1 2
Police Facility 0 0
Other Facilities 0 2
Total Facilities 73 14
Total Replacement Costs $216,764,045 $41,618,775
Source: FEMA National Flood Hazard Layer (NFHL)
In addition to the CFs, land within flood hazard zones amounts to approximately 20% of the City. This amount of land within flood hazard zones can include a significant number of homes and businesses. While this can be a significant amount of vulnerable properties, there is still some uncertainty, as changing precipitation patterns can cause flooding in areas that have not experienced such conditions before.
Dam Failure/Inundation
The extent to which dam failure events threaten physical assets in the City depends on several factors, including the volume of water released, the distance from the dam failure site, and the surrounding topography. Some facilities, such as Day Creek and Demens Creek Debris Basin, have smaller storage capacities, resulting in
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comparatively smaller inundation areas and lower potential consequences. Other reservoirs, like San Sevaine (the largest basin), Deer Canyon, and Cucamonga Creek, have large storage capacities or are located near assets that are expensive to replace.
Table 4-13 identifies the physical assets in Rancho Cucamonga that are threatened by the potential failure of the following dams: Alta Loma Basin, Etiwanda Basin, San Sevaine Basin, Demens Creek Debris Basin, Cucamonga Creek, Day Creek, and Deer Canyon.
TABLE 4-13. CRITICAL FACILITIES (DAM FAILURE)
Dam Facility
San
Sevaine
Etiwanda
Basin
Demens
Creek
Day
Creek
Deer
Canyon
Alta
Loma
Basin
Cucamonga
Creek
Bridge 24 6 6 0 19 6 21
City Facility 0 0 0 0 0 0 0
Fire Facility 0 0 1 0 0 0 0
Parks 0 1 1 0 0 0 0
Police Facility 0 0 0 0 0 0 0
Other
Facilities
0 0 0 0 0 0 0
Total Facilities 24 7 8 0 19 6 21
Total
Replacement
Costs**
$72 M $18 M $22.5 M $0 $57 M $18 M $63 M
** Based on the City of Rancho Cucamonga insured replacement values and City-provided estimates.
If any of these dams were to fail at maximum capacity and release the water stored in their reservoirs, it would threaten various assets in Rancho Cucamonga. The dams expected to impact the greatest number of facilities include San Sevaine, Cucamonga Creek, and Deer Canyon. Based on replacement cost values, the San Sevaine dam's impacts could impact assets totaling approximately $72 million, based on current asset valuation information.
Social Threat
Flooding
The threat of flooding will primarily affect residents in the 100-year and 500-year flood zones, many of whom live along drainage channels within the City. Flood depths may be sufficient to inundate curb lines, sidewalks, roadways, and low-lying areas during significant storm events. Such flooding would likely inundate curb cuts and sidewalks to
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some extent. People in Rancho Cucamonga who walk or bike as their primary mode of transportation may face greater mobility challenges if they lack access to alternative transportation. Seniors, people with disabilities, and low-income people are those most likely to be threatened. Table 4-14 shows the proportions of Rancho Cucamonga’s vulnerable populations who are likely to face a greater threat from a flood event in the City.
TABLE 4-14. FLOOD HAZARD THREATENED POPULATIONS
Flood Hazard Zone 100-Year Flood 500-Year Flood
City of Rancho
Cucamonga
Total Population* 2,791 12,969 174,772
Total Households* 930 3,940 57,984
Median household income * $154,134 $137,817 $112,514
Renter Households* 12.3% 28.9% 39.8%
Percentage of households with at
least one person living with a
disability** 27.6% 21.9% 22.5%
Percentage of households living
below the poverty limit** 5.6% 7.3% 8.6%
Percentage of households with at
least 1 person aged 65+** 43.1% 26.4% 29.5%
Area Affected by Hazard (Square
mile)**
6.15 sq miles
[13.2%]
3.38 sq miles
[7.3%] 46.51 sq miles
Sources: Esri Community Analyst 2024 Estimates (population, households, median household income, renter households); U.S. Census Bureau ACS 2019–2023 5-Year Estimates (disability status, poverty status, and age 65+ population).
Note: ACS 2024 estimates were used where available; otherwise, ACS 2019-2023 five-year estimates were utilized.
Compared to the citywide average, households within the 100-year flood zone have a higher median household income, a lower reported percentage of households with one or more persons living with a disability, higher poverty rates, lower percentages of households with one member aged 65+, and a higher percentage of households aged 65+ living alone. Households within the 500-year flood zone also have a higher median household income than the citywide average and lower poverty rates. However, the 500- year flood zone has a lower percentage of households with one member aged 65+, a lower percentage of households with one or more persons living with a disability, and a lower percentage of households aged 65+ living alone than the citywide average.
Additionally, flooding events are typically associated with rainstorms, which can impact people who are experiencing homelessness. If these populations are caught outside during floods without shelter, they could be disproportionately affected. Though floodwaters in Rancho Cucamonga are not expected to exceed one foot, a depth of six
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inches may render any makeshift structures uninhabitable. Possessions such as sleeping bags or electronic devices may be damaged or swept away by the floodwaters.
Dam Failure/Inundation
Dam failure hazards in the City would affect a variety of downstream properties. Table 4-15 identifies the potential impacts of each mapped dam's failure and the populations that could be affected. Based on this analysis, the Deer Canyon Dam inundation area would affect the greatest number of people, while the Cucamonga Creek Dam inundation area would affect the largest number of households and has the lowest median household income among the populated inundation areas. The Cucamonga Creek inundation area also has the highest reported percentage of households with one or more persons living with a disability. However, these demographic characteristics should be interpreted with caution, as some inundation areas have relatively small populations and households.
TABLE 4-15. DAM FAILURE THREATENED POPULATIONS
Threatened
Population
Metric
Rancho CucamongaSan SevaineEtiwanda Basin* Demens CreekDay Creek* Deer CanyonAlta Loma BasinCucamonga Creek Total
Population 174,772 362 0 417 0 1,618 2,809 1,395
Total
Households 57,984 87 0 121 0 577 1,045 513
Median
Household
Income 2019
$112,514 $162,616 $0 $160,015 $0 $93,582 $111,098 $127,296 Percent of
Households
with One or
More Persons
with a
Disability
39.8% 20.2% 0.0% 5.7% 0.0% 30.0% 26.9% 52.9%
Percent of
Households
under Poverty
Line
22.5% 10.3% 0.0% 23.1% 0.0% 24.3% 27.7% 8.4%
Percentage of
households
with one
member aged
65+
8.6% 6.9% 0.0% 2.5% 0.0% 6.4% 8.7% 13.8%
Percentage of
households
aged 65+ living
alone
29.5% 13.8% 0.0% 38.8% 0.0% 20.3% 35.3% 17.9%
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TABLE 4-15. DAM FAILURE THREATENED POPULATIONS
Threatened
Population
Metric
Rancho CucamongaSan SevaineEtiwanda Basin* Demens CreekDay Creek* Deer CanyonAlta Loma BasinCucamonga Creek Area Affected
by Hazard
46.51 sq
miles
0.47 sq m
(1%)
.019 sq m
(0.4%)
0.32 sq m
(0.7%)
.18 sq m
(0.4%)
.33 sq m
(0.7%)
0.52 sq m
(1%)
0.27 sq m
(0.5%)
Sources: Esri Community Analyst 2024 Estimates (population, households, median household income, renter households); U.S. Census Bureau ACS 2019–2023 5-Year Estimates (disability status, poverty status, and age 65+ population).
Note: ACS 2024 estimates were used where available; otherwise, ACS 2019-2023 five-year estimates were utilized.
* Due to the size of the inundation area, demographic information is unable to be calculated for Etiwanda Basin and Day Creek.
Other Threats
Flooding
Flooding may temporarily disrupt all types of transportation in the City. Debris carried by floodwaters can block roadways, hinder vehicles' access, and potentially affect emergency response services. Rushing water only one foot deep is enough to carry small vehicles. A severe flood situation in which the maximum anticipated flood depth of 1 foot is reached may prevent people who own smaller vehicles from driving to work, reducing economic activity. Severe flooding that causes serious damage to homes and businesses may also reduce economic activity until repair work is completed.
Additionally, health issues may arise from flooding. Mold could become an issue if flooded properties are not properly repaired. There is also the potential for exposure to chemical/hazardous materials if flooding compromises certain facilities.
Flooding may also result in temporary power outages and disruptions to communications infrastructure where electrical equipment is damaged or access to facilities is restricted.
Dam Failure/Inundation
Dam failures are often triggered by other events (seismic shaking, intense rainstorms, etc.). Often, when these events occur, there would almost certainly be service disruptions in Rancho Cucamonga. Floodwater could rapidly inundate downstream portions of the City, disrupting utilities, such as water, power, heating, and other services, such as communications or transportation infrastructure, especially since most of the vulnerable facilities are bridges within the City. Residents may find that street lighting and traffic signals may be temporarily disabled if the inundation area interferes with the electrical systems that control them. The rapid inundation of water would sweep
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up any debris, which could block roads and impede traffic flow. Water would most likely inundate roadways and other low-lying, flat areas, such as parking lots, open spaces, and schoolyards. People’s mobility in these areas would likely be restricted or even impossible in severe scenarios. Any unprotected or unhoused mechanical or electrical equipment that is not adequately elevated would become waterlogged and inoperable until crews can perform repairs or, if necessary, replacement.
Changes in Population and Land Use Development
Flooding
Continued population growth, infill development, and redevelopment may increase the number and value of structures, infrastructure, and community assets exposed to flooding hazards within Rancho Cucamonga. Although much of the City lies outside mapped Special Flood Hazard Areas59, future development may increase the potential consequences of localized flooding, stormwater runoff, debris flows, and drainagerelated impacts.
As urban development increases impervious surfaces such as roads, parking lots, and buildings, stormwater runoff may increase if not properly managed. Rancho Cucamonga's development standards, stormwater management requirements, floodplain regulations, and drainage infrastructure improvements are intended to reduce flood risk60; however, continued growth may increase the number of residents, businesses, and public facilities that could be affected by future flooding events.
Dam Failure/Inundation
Future population growth, infill development, and redevelopment in areas subject to dam inundation may increase the number of residents, businesses, public facilities, and infrastructure exposed to a potential dam failure. Although the probability of dam failure remains low, continued development within inundation areas could increase the potential consequences of such an event by increasing population exposure, economic losses, and demands on emergency response and evacuation operations.
As Rancho Cucamonga continues to develop, coordination between land use planning, emergency management, and infrastructure planning will remain important to reducing vulnerability within identified dam inundation areas. Continued adherence to development regulations, emergency notification systems, and evacuation planning efforts will help reduce future risk to people and property. 59 First Street. Does San Bernardino County have Flood Risk? https://firststreet.org/county/san-bernardino-countyca/6071_fsid/flood 60 City of Rancho Cucamonga General Plan, Safety Element
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Climate Change Vulnerability
Flooding
Climate change is expected to increase the frequency and severity of extreme precipitation events, including atmospheric rivers, which may heighten flood risk, trigger debris flows, and strain stormwater infrastructure.61 Recent statewide research has also highlighted the potential for California to experience rare but catastrophic flood events associated with prolonged atmospheric river activity. Increased wildfire activity may also increase post-fire flooding and debris-flow susceptibility within upstream watersheds.
Dam Failure/Inundation
Climate change may indirectly influence dam inundation hazards through changes in precipitation patterns, runoff volumes, and storm intensity.62 Climate projections for California indicate an increased likelihood of extreme precipitation events and atmospheric rivers, which may lead to higher inflows to reservoirs and flood-control facilities during major storms.
Although dam safety is primarily governed by engineering design, maintenance, inspections, and operational procedures, more frequent or intense storm events may increase operational demands on dam and reservoir systems. As a result, climate change may increase the complexity of reservoir management and emergency preparedness activities associated with dam-related hazards. However, climate change is not expected to directly increase the probability of dam failure. 61 USGS. (2018). ARkStorm Scenario. https://www.usgs.gov/programs/science-application-for-riskreduction/science/arkstorm-scenario?utm 62 Bureau of Reclamation. (2024). Incorporating Climate Change into the Safety of Dams Flood Risk Analysis Process. https://www.usbr.gov/watersmart/climate/docs/TM-ENV-2024-002_CCCS-2022- 004_Climate_Change_Safety_of_Dams_Flood_Hazard.pdf
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THREAT PROFILE: SEVERE WEATHER
Physical Threat and Vulnerability
Extreme Heat
Extremely high temperatures can cause roads to deform and buckle as the pavement expands in the heat, especially in poorly maintained areas. Power lines and other components of the electrical grid are less effective at higher temperatures and may be damaged by stress during extreme heat events. Dark roofs, pavement, and other impervious surfaces absorb and retain heat, contributing to the urban heat island effect.
This urban heat island effect is strongest during hot periods when the sun is at its peak.
Drought
Drought is not expected to directly damage most physical assets within Rancho Cucamonga; however, prolonged drought conditions may affect landscaping, urban vegetation, open space resources, and water-dependent facilities. It is possible that any water delivery infrastructure not used, or used less than usual, may fall into disrepair to some degree if maintenance is deferred. Lower water pressures may cause some aged water pipes to release rust particles into the water supply. Amenities within facilities, like water features and landscaping, could be affected by reduced watering. If dead or dying vegetation becomes a nuisance, the City may have to replace or retrofit locations affected.
Severe Wind
Intense winds likely pose the greatest threat to physical structures, particularly from trees or branches falling onto buildings and causing substantial damage. Older structures with deferred maintenance or not retrofitted for high-wind conditions may suffer greater damage than newer/updated structures. Utility lines and wooden utility poles face an elevated risk of wind damage, as do buildings without reinforced roofs.
Another physical threat associated with severe wind is wildfire impacts and electric utilities' current practice of conducting PSPS activities. During high-wind events, these shutoffs may affect structures that rely on electricity for normal operations. See social threats for population impacts that may also result from these events.
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Social Threat
Extreme Heat
Whereas a heat event can be relatively harmless for those with reliable means of staying hydrated and cool, it can be deadly for others. Young children, the elderly, or people suffering from serious medical conditions are physiologically more vulnerable to heatstroke. Some senior citizens also take medicines that can make it harder for their bodies to maintain a safe internal temperature, creating an additional threat from extreme heat events. Young children may not be aware of the signs of dehydration or how to protect themselves from heatstroke.
Persons experiencing homelessness are particularly vulnerable during extreme heat events, especially those who are unsheltered. Individuals without consistent access to cooling, hydration, medical care, transportation, or shelter may face elevated risks of heat exhaustion, heatstroke, dehydration, and other heat-related illnesses. Recent Point-in-Time counts indicate that Rancho Cucamonga continues to have a population of persons experiencing homelessness who may require additional outreach and support during extreme heat events (101 people during 2026 PIT count).63 Sudden spikes in heat can catch people by surprise. Stores can rapidly sell out of fans, air-conditioning units, or drinking water during a heatwave. Many lower-income households live in older, poorly insulated, and energy-inefficient housing and cannot afford to run their air conditioning, a situation further compounded by the threat of PSPS events. During these events, extreme heat may affect larger portions of the City and populations that would not be considered vulnerable under normal circumstances.
Drought
Droughts are unlikely to cause serious social threats to Rancho Cucamonga households, though residents and business owners in the City may experience financial costs associated with water conservation efforts. Those with limited access to financial resources, such as low-income households or seniors, could be hit harder if higher water fees are imposed during a severe drought.
Severe Wind
Vulnerable populations may be challenged during severe wind events for several reasons. Housing and structures damaged during an event may become uninhabitable 63 San Bernardino County. 2026. Homeless Count & Survey Report 2026. https://sbchp.sbcounty.gov/communityprojects/point-in-time-count/#docaccess-88bc8dbdb9cdcf5e4939605cbc697190
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or expensive to repair, which could strain renters/ homeowners if they cannot make the repairs. If relocation is required, the change in location could place additional strain on the resident. If businesses are damaged, cleanup and repairs may require closing the business, thereby affecting the City's economic activity. For residents who rely on public transportation, walking, or biking, exposure to severe winds could impede travel or delay arrival. Other vulnerable populations include those who work outdoors (e.g., construction workers, landscapers).
Other Threats
Severe weather events, including Santa Ana winds and winter storms, may damage electrical transmission lines, utility poles, transformers, substations, and other components of the electrical distribution system. Damage to electrical infrastructure may result in localized or widespread power outages affecting homes, businesses, traffic signals, communications systems, and critical facilities. The severity of impacts generally depends on the extent of infrastructure damage and the duration of service interruptions. Additional discussion of power outages and energy reliability is provided in the Power Failure or Energy Shortage hazard profile.
Extreme Heat
Extreme Heat for any length of time can affect other hazards and risks within the city as well. For example, it can create a spike in electricity demand, leading to power outages, food insecurity, and increased transmission of vector-borne diseases. Coupled with extreme wind, it can cause or spread wildfires and jeopardize additional neighborhoods/communities. Extreme heat may also increase demand for cooling centers and emergency medical services.
Drought
A typical drought is not expected to cause any service outages in Rancho Cucamonga.
However, an exceptional drought may restrict water use by residents or businesses in the City. Trees that are not adequately adapted to lower irrigation levels could perish, altering the City’s aesthetic appearance and long-term air quality. Any open spaces with extensive lawns may start to die, turning brown, which could discourage residents from using these parks and open spaces. In addition, long-term drought conditions can reduce the soil's ability to retain water. When this occurs, runoff from these areas may increase, potentially causing downstream flooding and erosion.
Severe Wind
Southern California and the City of Rancho Cucamonga will both suffer from seasonal Santa Ana Winds for the foreseeable future. Extreme wind events such as these can
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make other risks, such as wildfire, exponentially worse. Severe wind events may affect aviation operations at nearby airports, increase wildfire ignition and spread potential, disrupt transportation systems, and contribute to utility outages.
Changes in Population and Land Use Development
Extreme Heat
Future population growth may increase the number of residents exposed to extreme heat events, particularly vulnerable populations such as older adults, young children, individuals experiencing homelessness, outdoor workers, and persons with underlying health conditions. Additional urban development may also contribute to localized heat island effects where concentrations of buildings, pavement, and other impervious surfaces increase ambient temperatures. As a result, future development may increase the potential public health impacts associated with extreme heat.64 Drought
Continued population growth and development may increase demand for water resources within Rancho Cucamonga. Additional residential, commercial, industrial, and landscaping water demands could increase vulnerability during prolonged drought periods, particularly if future droughts coincide with increased water consumption.
Although regional water providers continue to invest in water conservation, storage, and supply diversification, future growth may increase the potential impacts of water shortages and drought-related restrictions.65
Severe Wind
Continued development may increase the number and value of structures, infrastructure, utilities, and community assets exposed to severe wind events. Additional development may also increase the potential for wind-related damage to buildings, trees, power lines, transportation infrastructure, and communication systems. As the City continues to grow, severe wind events may affect a larger number of residents, businesses, and public facilities.
64 California Natural Resources Agency. (2024). California Climate Adaptation Strategy. https://resources.ca.gov/Initiatives/Building-Climate-Resilience/2024-State-Adaptation-Strategy-Update 65 California Department of Water Resources. California Water Plan. https://water.ca.gov/programs/californiawater-plan
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Climate Change Vulnerability
Extreme Heat
Climate change is expected to increase the frequency, duration, and intensity of extreme heat events throughout Southern California. Rising temperatures may increase heatrelated illnesses, place additional strain on energy systems, increase cooling demands, and disproportionately affect vulnerable populations. Because extreme heat is projected to become more common under future climate conditions, Rancho Cucamonga’s vulnerability to heat-related impacts is expected to increase.66 Drought
Climate change is expected to increase temperatures throughout Southern California and alter historical precipitation patterns. These changes may contribute to more frequent, prolonged, and severe drought conditions by increasing evaporation, reducing soil moisture, and increasing water demand. As a result, climate change is expected to increase Rancho Cucamonga’s vulnerability to drought and associated water supply challenges.67
Severe Wind
The relationship between climate change and severe wind events remains uncertain.
While climate change is not expected to directly increase the frequency of Santa Ana winds or other severe wind events affecting Rancho Cucamonga, hotter and drier conditions may intensify their impacts. Severe winds occurring during periods of drought or elevated wildfire conditions may contribute to increased wildfire ignition, fire spread, utility disruptions, and other secondary impacts.68
66 Ibid.
67 California Department of Water Resources. California Water Plan. https://water.ca.gov/programs/californiawater-plan 68 Ibid.
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THREAT PROFILE: HUMAN-CAUSED HAZARDS
Physical Threat and Vulnerability
Cyber Threat
Cyber threats would have a limited impact on physical assets. The extent of this impact would be limited to City-owned computer and network infrastructure.
Terrorism/Mass Casualty Incident
There is no way to predict which of Rancho Cucamonga’s facilities or assets may be impacted by a mass casualty incident/act of terrorism since the perpetrator's reasoning is often complex or not easily understood. Generally, these types of incidents occur at places of political, economic, or cultural importance. If the perpetrator's motive is to shut down City or regional government activity for some time, they may instead target infrastructure, such as water systems, utility delivery systems, or transportation networks. In this situation, bridges may become prime locations for such activities. The financial losses that may result would depend on the degree of destruction associated with the activity. If the incident involves the destruction of physical assets, the City or property owners' costs would likely be immense.
Transportation Accident
Transportation accidents may result in injuries, fatalities, property damage, hazardous materials releases, and disruptions to critical transportation infrastructure. Rancho Cucamonga is traversed by several major transportation corridors, including Interstate 10, Interstate 15, State Route 210, regional freight rail lines, and numerous arterial roadways that support the movement of commuters, freight, and hazardous materials throughout Southern California. Accidents involving passenger vehicles, commercial trucks, rail operations, or hazardous materials transportation have the potential to affect nearby residences, businesses, critical facilities, and transportation networks.
Transportation accidents may damage roadways, bridges, utility infrastructure, traffic control systems, and adjacent properties. Incidents involving commercial vehicles or hazardous materials may result in secondary impacts such as fires, explosions, roadway closures, environmental contamination, or evacuations. The severity of impacts generally depends on the type of transportation involved, the volume of traffic, the presence of hazardous materials, weather conditions, and the proximity of surrounding development to the incident location.
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Because Rancho Cucamonga serves as a regional transportation hub within the Inland Empire, disruptions along major transportation corridors may affect local mobility, emergency response access, freight movement, and regional economic activity.
Social Threat
Cyber Threat
Cyber threats may affect residents and businesses throughout the City. While most cyber threats target large entities such as major corporations and government agencies, all residents could become victims.
Terrorism/Mass Casualty Incident
Since mass casualty incidents/acts of terrorism could occur anywhere in Rancho Cucamonga, all groups are potentially threatened by these incidents; however, the extent of the threat would depend upon the event's type and magnitude. For example, an active shooter situation may be isolated to a single location, whereas a larger-scale incident may affect multiple locations. Some locations are more likely to be targeted than others, including, but not limited to, medical facilities, government buildings, schools, and financial institutions. Populations that frequently visit these areas may face a greater threat than the average person. For instance, seniors, pregnant women, and persons with disabilities are more likely to visit medical facilities than other subpopulations in the City. Should an incident occur at one of these facilities or within the community (overwhelming hospital resources), these groups are expected to be disproportionately affected.
An incident at a government building or financial institution is more likely to threaten seniors or lower-income individuals who rely on in-person transactions rather than online options.69, 70 As such, their use of these services in-person may place them in harm’s way. An incident at James L. Brulte Senior Center or at any bank in the City is likely to pose a greater threat to these groups. Seniors and persons with limited income may be challenged if they need to shelter in place or evacuate during an incident that requires additional services, assistance, and/or medical treatment. 69 Smith, A. April 2014. Older Adults and Technology Use. https://www.pewinternet.org/2014/04/03/older-adultsand-technology-use/ 70 Anderson, M., Kumar, M. May 2019. Digital divide persists even as lower-income Americans make gains in tech adoption. https://www.pewresearch.org/fact-tank/2019/05/07/digital-divide-persists-even-as-lower-incomeamericans-make-gains-in-tech-adoption/
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Transportation Accident
Transportation accidents may affect all residents of Rancho Cucamonga; however, certain populations may experience greater vulnerability. Older adults, persons with disabilities, young children, and individuals with access and functional needs may face additional challenges during evacuations, roadway closures, or emergency response operations resulting from major transportation incidents. Individuals who rely on public transportation, paratransit services, walking, or bicycling may also experience disproportionate impacts when transportation corridors are disrupted.
Transportation accidents involving hazardous materials, fires, or extended roadway closures may require shelter-in-place orders, evacuations, or detours affecting nearby residential neighborhoods, schools, businesses, and healthcare facilities. Lowerincome households may face greater challenges if transportation disruptions affect access to employment, healthcare, childcare, or other essential services. In addition, individuals involved directly in transportation accidents may experience physical injuries, emotional trauma, or financial hardship associated with medical treatment, property damage, and lost income.
Other Threats
Cyber Threat
The greatest impact a cyber threat could have on the City itself would be a complete shutdown of city services and programs. Electricity, natural gas, and water could be shut off for extended periods if a cyber threat compromised the control systems. Additionally, a loss of control over streetlights, traffic lights, and railroad crossings could occur. To the average citizen, personal information, identity, and financial records could be stolen.
As society becomes increasingly dependent on technology and interconnected systems, cyber threats are expected to continue evolving in complexity, frequency, and potential impact.
Terrorism/Mass Casualty Incident
A mass-casualty incident could result in fatalities, injuries, psychological trauma, property damage, and disruption of community services. Depending on the incident's location and severity, transportation corridors, government facilities, schools, businesses, and critical infrastructure could be temporarily closed or disrupted.
Emergency response resources may be strained by evacuation, law enforcement, medical treatment, and recovery operations. Significant incidents could also result in
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economic losses, reduced public confidence, and long-term social impacts on the community.71
Transportation Accident
Major transportation accidents may result in secondary impacts that extend beyond the immediate incident location. These impacts may include hazardous materials releases, fires, explosions, utility disruptions, traffic congestion, road closures, environmental contamination, and delays to emergency response operations. Transportation accidents involving rail corridors or commercial trucking routes may disrupt regional freight movement and supply chains, affecting businesses and economic activity throughout the region.
Significant roadway closures may also affect evacuation routes and emergency access during other hazard events, including wildfires, floods, earthquakes, and severe weather. Because many transportation corridors are closely interconnected with utility systems, communications infrastructure, and regional commerce, transportation accidents can create cascading impacts across multiple sectors of the community.
Changes in Population and Land Use Development
Cyber Threat
As Rancho Cucamonga continues to grow and become increasingly reliant on technology, telecommunications systems, cloud-based services, and interconnected infrastructure, exposure to cyber threats is expected to increase. Additional population growth, expanded municipal services, and increased use of digital technologies may create additional opportunities for cyberattacks targeting government operations, critical infrastructure, businesses, and residents. As a result, the potential consequences associated with cyber incidents may increase as the City's reliance on technology continues to expand.72
Terrorism/Mass Casualty Incident
Future population growth and continued economic development may increase the potential consequences associated with a mass-casualty incident. Larger populations, increased commercial activity, major transportation corridors, public gathering places, and community events may increase the number of people potentially exposed to such incidents. Although the likelihood of a terrorism-related event remains difficult to predict, 71 Federal Emergency Management Agency Threat and Hazard Identification and Risk Assessment (THIRA) Guide.
72 CISA. Cybersecurity Best Practices. https://www.cisa.gov/topics/cybersecurity-best-practices
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future growth may increase the potential impacts to life safety, emergency response operations, and community recovery efforts.73
Transportation Accident
Continued population growth, commercial development, logistics activity, and regional transportation demand may increase exposure to transportation accidents within Rancho Cucamonga. Additional residential and employment growth may increase traffic volumes on major freeways, arterial roadways, and freight corridors, increasing the potential for vehicle collisions and transportation-related incidents.
Future development associated with warehousing, distribution, commercial activity, and regional transportation improvements may also increase the movement of commercial vehicles and hazardous materials through the City. As the number of residents, workers, and visitors continues to grow, transportation accidents may affect more people, structures, businesses, and critical facilities. Continued transportation planning, roadway improvements, traffic safety programs, and coordination with regional transportation agencies will remain important for reducing future transportation-related risks.
Climate Change Vulnerability
Cyber Threat
Climate change is not expected to directly affect the frequency or occurrence of cyber threats. Cyber incidents are primarily driven by human activity, technological vulnerabilities, and evolving threat actors rather than climatic conditions. Therefore, climate change is not anticipated to significantly alter vulnerability to cyber threats.
Terrorism/Mass Casualty Incident
Climate change is not expected to directly affect the frequency or occurrence of terrorism or mass-casualty incidents. These hazards are primarily influenced by social, political, ideological, and criminal factors rather than environmental conditions.
Consequently, climate change is not anticipated to significantly alter Rancho Cucamonga's vulnerability to terrorism-related hazards. 73 Federal Emergency Management Agency Threat and Hazard Identification and Risk Assessment (THIRA) Guide.
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Transportation Accident
Climate change may indirectly influence the risk of transportation accidents through changes in weather conditions and impacts on transportation infrastructure. More frequent extreme heat events may contribute to pavement deterioration, roadway buckling, and increased vehicle stress, while intense precipitation events may reduce visibility, create hazardous driving conditions, and increase the likelihood of vehicle collisions. Flooding, severe storms, wildfires, and other climate-related hazards may also damage transportation infrastructure, disrupt traffic operations, and increase the potential for transportation-related incidents.
Although climate change is not expected to directly cause transportation accidents, changing environmental conditions may increase stress on transportation systems and contribute to conditions that elevate accident risk. As a result, climate change may indirectly increase vulnerability to transportation-related disruptions and associated secondary impacts.
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THREAT PROFILE: HAZARDOUS MATERIALS
RELEASE
Physical Threat and Vulnerability
Hazardous materials (HAZMAT) releases may damage buildings, infrastructure, utilities, transportation systems, and other community assets depending on the type, quantity, and location of the released material. Corrosive hazardous materials can damage the exteriors of any buildings or structures designated as a CF. Flammable hazardous materials can be ignited and may cause nearby CFs to sustain damage. Generally, sites closer to the release origin of hazardous materials are at greater risk than those farther away.
Table 4-16 identifies the number of physical assets in Rancho Cucamonga that are threatened by a hazardous materials release within 500 feet of a site that stores or uses hazardous materials. A total of 83 assets are located near hazardous materials sites within the City. Based on replacement cost estimates, the total potential losses for these assets exceed $237 million.
TABLE 4-16. CRITICAL FACILITIES (HAZMAT BUFFER – 500FT) Category Number of Facilities
Bridge 49
City Facility 10
Fire Facility 7
Parks 9
Police Facility 2
Other Facilities 6
Total Facilities 83
Total Replacement Costs** $237,169,329
** Based on the City of Rancho Cucamonga insured replacement values In addition to fixed facilities, hazardous materials are routinely transported through Rancho Cucamonga via major freeways, arterial roadways, rail corridors, and utility infrastructure. Transportation-related releases may affect areas beyond the immediate source location and may result in roadway closures, evacuations, environmental contamination, fires, or explosions.
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Social Threat
The threat of a hazardous materials release affects those closest to sources, including industrial sites, gas stations, gas transmission lines, and sewer mains. Populations living near hazardous materials sites are at greater risk of exposure to chemicals and substances that could adversely affect health. Many of the City's commercial, industrial, utility, and transportation-related hazardous materials sites are located south of Foothill Boulevard, resulting in a greater concentration of potential sources of exposure within this portion of the community. Residential uses located within this part of the City are at greater risk of exposure under normal conditions and during a hazard event.
Rancho Cucamonga residents living next to major transportation infrastructure— highways or major arterial streets—face a greater risk of being affected by a hazardous materials release because trucks or vehicles transporting hazardous materials may spill their contents into the environment in a collision. Residents living near the major transportation corridors running through the City (I-15, SR-210) are at greater risk of transportation-related hazardous materials release than residents living in other parts of the City.
Groups such as older adults, lower-income households, renters, and persons with disabilities may face greater challenges during hazardous materials incidents because they may have fewer resources available for evacuation, temporary relocation, medical treatment, or recovery.
Other Threats
A hazardous materials release could threaten the City’s and potentially the region’s transportation networks. Large sections of the local road or rail systems may be closed to keep people away from hazardous material contamination and allow remediation and cleanup activities to proceed. If a highly corrosive hazardous material is released, it could cause significant damage to the exteriors of homes and businesses in the surrounding area. Hazardous materials could also harm the City’s landscaping/urban forest, resulting in the deaths of city-planted and maintained trees and foliage.
Hazardous materials incidents may also result in utility disruptions, power outages, evacuations, and transportation delays that affect areas well beyond the immediate release location.
Changes in Population and Land Use Development
Continued population growth, economic development, and transportation activity may increase the potential consequences of hazardous materials releases in Rancho Cucamonga. Additional residential, commercial, industrial, and public development may
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increase the number of people, structures, and critical facilities potentially exposed to accidental or intentional hazardous materials incidents.
The City's extensive transportation network, including major roadways and rail corridors, supports the movement of hazardous materials throughout the region. As development and transportation activity continue to increase, the potential impacts associated with a hazardous materials release may also increase due to greater population exposure and increased demands on emergency response and recovery operations.74 Rancho Cucamonga's proximity to regional freight corridors, distribution facilities, and transportation infrastructure increases the movement and storage of hazardous materials throughout the community.
Climate Change Vulnerability
Climate change is not expected to directly increase the frequency of hazardous materials releases; however, changing environmental conditions may increase the likelihood of accidental releases occurring during other hazard events. However, climate-related hazards such as wildfires, flooding, severe storms, and extreme heat may increase the risk of accidental releases by affecting transportation systems, storage facilities, pipelines, utilities, and other infrastructure that handle hazardous materials.
For example, flooding may damage or inundate facilities that store hazardous substances, while wildfire and extreme heat may affect pipelines, fuel storage facilities, electrical systems, or transportation corridors. As a result, climate change may indirectly increase the potential consequences associated with hazardous materials incidents during extreme events.
74 California Governor's Office of Emergency Services Hazardous Materials Program Guidance.
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THREAT PROFILE: AIRCRAFT INCIDENT
Physical Threat and Vulnerability
All structures located within the planning areas surrounding the Ontario International Airport and Cable Airport are at an elevated risk of aircraft incidents, predominantly associated with landing, take-off, and approach activities. Because both airports are located outside Rancho Cucamonga city limits, the greatest direct exposure occurs in areas closest to the airport approach, departure, and flight paths. Beyond this planning area, the risk associated with aircraft incidents is limited to flyover activities above the City. Incidents overhead can send debris and materials from the aircraft crashing onto any structures or physical assets below. Even if the aircraft does not crash within the City, falling debris could land on and damage structures there.
Recent aircraft incidents occurring at Ontario International Airport and Cable Airport demonstrate the continued presence of aviation-related risk within the region, although the likelihood of a significant aircraft incident affecting Rancho Cucamonga remains relatively low.
Social Threat
Although aircraft incidents are relatively infrequent, they could affect residents, employees, visitors, and travelers throughout Rancho Cucamonga. Typically, populations closer to Ontario International Airport or Cable Airport are more likely to be impacted than those in portions of the City farther away.
Residents and employees in areas impacted by an aircraft accident may experience property damage or loss and/or emotional distress resulting from the loss of family or friends in the crash or from witnessing the event or its aftermath. Lower-income households may face greater challenges in recovering from aircraft incidents because they have fewer financial resources for temporary housing, repairs, transportation, or replacement of damaged property.
Other Threats
Depending on the severity of the aircraft incident, some services in the City could be temporarily disrupted. For example, falling debris from an aircraft accident could damage or destroy a section of the City's power transmission lines, cutting off power to residents and businesses. Debris could also fall onto a roadway, obstructing the normal flow of traffic through the City. A more severe aircraft accident in which an entire aircraft crashes into a section of the City would likely ignite a fire that could impact the area where the plane went down. Any transmission wires or pipelines at the crash site would
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likely be affected to some degree, resulting in partial or complete outages of utility services in those sections of the City. A severe aircraft incident at a major employment center in the City would almost certainly close employers in the crash area until authorities deem it safe for employees to return to work, resulting in a loss of economic activity in the City.
Aircraft incidents may also result in hazardous materials releases, utility disruptions, power outages, fires, transportation delays, and emergency access restrictions that affect areas beyond the immediate crash location.
Changes in Population and Land Use Development
Continued population growth, infill development, and redevelopment may increase the number of residents, businesses, public facilities, and infrastructure potentially exposed to aircraft incidents. Rancho Cucamonga's proximity to major regional airports and air transportation corridors means that future development could increase the potential consequences associated with an aircraft accident by increasing the number of people and assets located within affected areas.
Although aircraft incidents remain relatively infrequent, continued growth may increase potential economic losses, emergency response demands, and recovery requirements should an incident occur. Land use planning, airport compatibility planning, and building occupancy considerations help reduce future vulnerability by limiting incompatible development in areas most affected by aviation operations.
Climate Change Vulnerability
Climate change is not expected to directly increase the frequency of aircraft incidents affecting Rancho Cucamonga. Aircraft accidents are primarily influenced by factors such as mechanical failure, human error, operational procedures, air traffic conditions, and weather-related hazards.
Climate change may indirectly affect aviation operations through more frequent extreme heat events, reduced visibility from wildfire smoke, and changes in weather conditions.
Extreme heat may affect aircraft performance and increase operational constraints, while wildfire smoke and severe weather may contribute to delays, diversions, or temporary disruptions to aviation activities.75 These factors may occasionally affect flight operations and airport activities; however, climate change is not expected to significantly alter Rancho Cucamonga's overall vulnerability to aircraft incidents. 75 Federal Aviation Administration Climate and Aviation Research Program.
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THREAT PROFILE: POWER FAILURE OR
ENERGY SHORTAGE
Physical Threat and Vulnerability
Power failures and energy shortage events can affect buildings, infrastructure, and essential services throughout Rancho Cucamonga. Electrical service is necessary for the operation of traffic signals, communications systems, water and wastewater facilities, fuel stations, refrigeration and heating/cooling systems, security systems, medical equipment, and municipal facilities. A localized outage may affect only a small number of customers, while a regional outage, PSPS, or grid reliability event could affect large portions of the City.
Critical facilities are especially vulnerable to prolonged power disruptions if backup power systems are unavailable, undersized, or unable to operate for the duration of the outage. Power disruptions may also affect transportation safety by disabling traffic signals and rail crossing equipment, disrupting water and wastewater operations, and limiting residents' and businesses' access to essential services. The severity of impacts depends on the duration of the outage, the number of customers affected, weather conditions during the outage, and the availability of backup power or redundant systems.
Social Threat
Power failures and energy shortages may disproportionately affect residents who rely on electricity for medical equipment, mobility devices, medication refrigeration, communication, heating, cooling, or access to transportation. Older adults, young children, individuals with disabilities or access and functional needs, individuals with limited English proficiency, outdoor workers, low-income households, and people experiencing homelessness may be more vulnerable during prolonged outages or extreme heat events.76
Loss of power can also affect households’ ability to receive emergency alerts, charge phones, store food safely, access elevators, operate garage doors, maintain indoor temperatures, and obtain timely information. During extreme heat, power outages may significantly increase health risks by limiting access to air conditioning and cooling resources. For businesses, outages can disrupt operations, cause economic losses, and reduce access to goods and services the community needs. 76 California Extreme heat Action Plan. (2022). https://mclist.us7.listmanage.com/track/click?u=afffa58af0d1d42fee9a20e55&id=797e1bca13&e=4445b5a765
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During extreme heat events, cooling centers and other air-conditioned public facilities (Table 4-17) may provide temporary relief for residents who lack access to adequate cooling and can help reduce the risk of heat-related illness during extended outages.
TABLE 4-17. COOLING CENTERS IN RANCHO CUCAMONGA
Center Address Phone
Archibald Library* 7368 Archibald Avenue, Rancho
Cucamonga, CA 91730
1-909-477-2720
James L. Brulte Senior Center 11200 Base Line Road, Rancho Cucamonga, CA 91701
1-909-477-2780
Paul A Biane Library 12505 Culture Center, Rancho
Cucamonga, CA 91739
1-909-477-2720
Source: Southern California Edison. Check Outage Status. https://www.sce.com/outages-safety/outagecenter/check-outage-status * In 2028, this facility will be replaced by the Diane Library at Lions Park Other Threats
Power failures and energy shortages may create cascading impacts across multiple hazard profiles. Severe wind events may damage transmission and distribution infrastructure, while wildfires and elevated fire weather may result in PSPS events intended to reduce wildfire ignition risk. Earthquakes may damage electrical infrastructure and substations, and cyber incidents may disrupt utility operations or municipal systems. Extreme heat may increase electricity demand and contribute to grid reliability concerns.
Extended outages may also affect emergency response, public safety, water supply, wastewater treatment, communications, traffic management, healthcare access, and business continuity. If outages occur during evacuation, sheltering, extreme heat, wildfire, or other emergency conditions, impacts may be more severe. Maintaining backup power, redundant communications, continuity planning, and coordination with utility providers will remain important for reducing cascading impacts.
Recent PSPS operations and regional grid reliability concerns demonstrate the interconnected nature of electrical infrastructure, public safety, transportation systems, communications networks, and community services.
Changes in Population and Land Use Development
Continued population growth, commercial development, increased reliance on electrically powered technologies, and the ongoing electrification of buildings and transportation systems may increase demand on the electrical grid over time. As a
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result, maintaining reliable energy supplies and resilient electrical infrastructure will become increasingly important for supporting community functions and reducing future risk.
Climate Change Vulnerability
Climate change may indirectly increase Rancho Cucamonga’s vulnerability to power outages and energy shortages. More frequent and intense extreme heat events are expected to increase electricity demand, particularly during peak summer periods when air conditioning use is highest. California’s grid operator may issue Flex Alerts when high electricity demand or reduced supply creates potential reliability concerns.77 Climate-related hazards may also increase the likelihood of utility disruptions. Wildfire risk, severe winds, dry vegetation, and low humidity can prompt utilities to implement PSPS to reduce the risk of wildfire ignition from electrical infrastructure.78 As a result, climate change may increase both the frequency and consequences of power disruptions by increasing cooling demand, straining energy infrastructure, and creating conditions that necessitate utility de-energization or emergency conservation measures.79
77 California ISO. (2025) Flex Alerts can plan an important role during extreme conditions. Energy Matters blog. https://www.caiso.com/about/news/energy-matters-blog/flex-alerts-can-play-an-important-role-during-extremeconditions 78 California Edison. Public Safety Power Shutoff – Decision-Making Fact Sheet. https://newsroom.edison.com/_gallery/get_file/?file_id=60677314b3aed3396d46711f&ir=1& 79 California ISO. (2025) Flex Alerts can plan an important role during extreme conditions. Energy Matters blog. https://www.caiso.com/about/news/energy-matters-blog/flex-alerts-can-play-an-important-role-during-extremeconditions
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CHAPTER 5 –
HAZARD MITIGATION STRATEGY
STRATEGY DEVELOPMENT PROCESS
Rancho Cucamonga’s hazard mitigation strategy is a comprehensive set of actions intended to reduce the impacts of hazard events. These hazard mitigation actions will help protect the safety and well-being of residents, visitors, CFs, other buildings and structures, key services, the local economy, and other important community assets.
Some actions will also support emergency preparedness, enabling a more effective community response to hazard events. Preparedness actions are not a required component of an LHMP, but they support and complement mitigation activities. The Committee chose to include them in the overall hazard mitigation strategy.
Use of Hazard and Threat Assessment
The Committee relied, in part, on the hazard profiles and threat assessments in this Plan to develop the actions of the mitigation strategy. A comprehensive set of mitigation actions that address relevant hazard scenarios and protect residents, businesses, and community assets in Rancho Cucamonga was prepared. The Committee ensured that the mitigation actions would help reduce damage from the most frequent types of hazard events, the most significant that may reasonably occur, and those with the greatest potential to harm the community. The Committee also drafted mitigation actions to help protect the most vulnerable community members and local assets.
CAPABILITIES ASSESSMENT
As part of the effort to draft mitigation actions, the City completed a capabilities assessment that reviewed existing policies, personnel, and technical resources to support hazard mitigation activities in Rancho Cucamonga. The hazard mitigation actions build on these resources' existing success and leverage their capabilities to support improved community resilience. The capabilities assessment looked at the following types of resources:
• Personnel resources: City employees and volunteers, and employees and volunteers at other agencies
• Plan resources: Advisory or enforceable plans adopted by the City or other agencies.
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• Policy resources: Policies adopted and implemented by the City or other agencies
• Technical resources: Data and tools available to the City • Financial resources: Funding mechanisms available to the City that support mitigation activities
As part of this assessment, the City has identified “Community Outreach & Engagement” as one of the resources listed above. Much of the City's outreach and engagement occurs in various formats and across a range of departments, as highlighted in this assessment.
Community outreach and engagement activities are carried out by multiple departments and programs, including ReadyRC, Healthy RC, Community Affairs, Library Services, Community Services, and the Community Outreach and Support Team (COAST), providing multiple avenues for public education, preparedness, and resilience-building.
Capabilities Improvement/Expansion
The City's ability to expand and enhance its mitigation capabilities will depend largely on available staffing, funding, technical resources, and organizational capacity. During implementation of this LHMP, the City should regularly evaluate opportunities to strengthen existing mitigation capabilities and identify new approaches for reducing risk.
FEMA and other State and Federal agencies continue to provide guidance, technical assistance, and funding opportunities that can support local mitigation efforts. Potential strategies for enhancing mitigation capabilities include:
1) Continuing to adopt, implement, and enforce current building codes, development standards, and hazard-resistant construction practices. Where feasible, the City should encourage development that exceeds minimum regulatory requirements to improve long-term community resilience. 2) Expanding outreach and engagement efforts to ensure that all segments of the community, including underserved and disproportionately impacted populations, have opportunities to participate in mitigation planning and implementation activities.
3) Strengthening coordination among City departments, special districts, regional agencies, nonprofit organizations, and private-sector partners to improve implementation capacity and leverage available resources. 4) Identifying opportunities to integrate hazard mitigation principles into other local planning mechanisms, including capital improvement programs, infrastructure planning, climate adaptation initiatives, emergency management programs, and land use planning efforts.
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5) Pursuing State, Federal, and private funding opportunities to support the implementation of mitigation actions and improve the effectiveness of existing programs.
6) During the annual LHMP review process, evaluate the status of mitigation actions, identify implementation barriers, and consider opportunities to expand, modify, or prioritize mitigation efforts based on changing conditions, emerging risks, and available resources.
The City of Rancho Cucamonga maintains a variety of planning, regulatory, administrative, technical, financial, and outreach capabilities that support implementation of hazard mitigation activities. These capabilities provide the framework through which the City identifies hazards, reduces risk, protects life and property, and enhances community resilience.
TABLE 5-1. RANCHO CUCAMONGA CAPABILITIES ASSESSMENT
Capability
Name
Capability
Type Description Mitigation Relevance Source
General Plan Plan The City's comprehensive
long-range planning document
establishes policies related to
land use, public facilities, open
space, mobility, housing,
safety, environmental
stewardship, and community
resilience. The General Plan
guides future development and
public investment decisions
throughout Rancho
Cucamonga.
Supports hazard mitigation by
incorporating safety,
environmental protection, climate
resilience, infrastructure planning,
and land-use policies that reduce
future risks from natural and
human-caused hazards.
PlanRC
2040
General
Plan (2021)
Safety
Element
Plan The Safety Element
establishes policies and
implementation measures
related to seismic hazards,
flooding, wildfire, hazardous
materials, emergency
preparedness, and climate
resilience.
Provides the primary policy
framework for reducing hazard
risk through land use planning,
development standards, and
emergency preparedness
initiatives.
PlanRC
2040
General
Plan –
Safety
Element
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TABLE 5-1. RANCHO CUCAMONGA CAPABILITIES ASSESSMENT
Capability
Name
Capability
Type Description Mitigation Relevance Source
Emergency
Operations
Plan (EOP)
Plan The City's Emergency
Operations Plan establishes
the framework for emergency
preparedness, response,
recovery, Emergency
Operations Center (EOC)
activation, resource
management, and coordination
with local, state, and federal
agencies. The EOP is
consistent with SEMS and
NIMS requirements.
Supports mitigation by identifying
hazards, improving preparedness,
enhancing interagency
coordination, and promoting
resilience before, during, and after
disasters.
2023
Emergency
Operations
Plan
Local Hazard
Mitigation
Plan
Plan Identifies hazards, assesses
vulnerability, and establishes
mitigation goals, objectives,
and actions to reduce longterm risk.
Serves as the City's primary
hazard mitigation planning
document and supports eligibility
for FEMA mitigation grant
programs.
2026
Rancho
Cucamonga
LHMP
Emergency
Operations
Center
(EOC)
Administrative
& Technical
The City maintains an
Emergency Operations Center
to coordinate emergency
response, information
management, resource
allocation, and recovery
operations during major
incidents.
Provides operational capability for
incident management, situational
awareness, resource
coordination, and implementation
of emergency protective
measures.
2023
Emergency
Operations
Plan
Adopted
Budget
Financial The City's annual budget
allocates financial resources to
municipal operations,
infrastructure improvements,
public safety programs,
technology investments,
emergency preparedness
activities, and community
resilience initiatives.
Provides a mechanism for funding
hazard mitigation projects,
infrastructure improvements,
emergency preparedness
initiatives, and long-term
resilience investments.
FY 2025/26
Adopted
Budget
Capital
Improvement
/ Major
Projects
Program
Financial The City's Major Projects
Program identifies, prioritizes,
and funds infrastructure and
facility improvements that
support community needs and
long-term resilience.
Provides a mechanism for
implementing hazard mitigation
projects, infrastructure upgrades,
facility improvements, and
resilience investments identified
through planning efforts.
FY 2025/26
Adopted
Budget –
Major
Projects
Program.
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TABLE 5-1. RANCHO CUCAMONGA CAPABILITIES ASSESSMENT
Capability
Name
Capability
Type Description Mitigation Relevance Source
Fire District Administrative
& Technical
The Rancho Cucamonga Fire
District provides fire
suppression, wildfire
preparedness, fire prevention,
emergency medical services,
public education, and
emergency response functions.
The District has also
implemented an Early Wildfire
Detection System along the
City's northern boundary.
Supports wildfire risk reduction,
public education, emergency
response, evacuation planning,
and hazard mitigation activities.
FY 2025/26
Adopted
Budget
Police
Department
Administrative
& Technical
Provides law enforcement,
evacuation support, traffic
control, public safety
communications, and
emergency response
coordination.
Supports emergency response,
evacuation operations, security,
and disaster recovery activities.
FY 2025/26
Adopted
Budget
Public Works
Department
Administrative
& Technical
Maintains transportation
infrastructure, storm drainage
systems, public facilities, and
essential municipal services.
Supports infrastructure resilience,
flood mitigation, debris removal,
emergency repairs, and postdisaster recovery.
FY 2025/26
Adopted
Budget
Emergency
Notification
System
Administrative
& Technical
The City maintains emergency
communication and public
notification capabilities to
distribute alerts, warnings, and
emergency information.
Supports evacuation, emergency
protective actions, public
awareness, and timely
dissemination of hazard
information.
ReadyRC /
2023
Emergency
Operations
Plan
Innovation &
Technology
(DoIT)
Administrative
& Technical
The Innovation and
Technology Department
manages information
technology systems,
cybersecurity functions,
communications infrastructure,
data management, and
municipal technology services.
Supports continuity of operations,
cybersecurity resilience,
emergency communications, GIS
applications, and critical
technology infrastructure.
FY 2025/26
Adopted
Budget
GIS Program Administrative
& Technical
A geographic information
system is used to collect,
manage, analyze, and display
spatial data.
Supports hazard mapping,
vulnerability analysis, evacuation
planning, critical facility
inventories, and mitigation project
prioritization.
General
Plan;
Innovation &
Technology
Department.
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TABLE 5-1. RANCHO CUCAMONGA CAPABILITIES ASSESSMENT
Capability
Name
Capability
Type Description Mitigation Relevance Source
Community
Improvement
Division
Regulatory The Community Improvement
Division enforces municipal
codes and regulations related
to property maintenance,
nuisance abatement, and
community safety.
Supports wildfire mitigation,
vegetation management, hazard
abatement, and maintenance of
safe community conditions.
FY 2025/26
Adopted
Budget
Building &
Safety
Regulatory Administers building permits,
inspections, code enforcement,
and implementation of state
and local construction
standards.
Ensures structures are designed
and constructed to current
building codes that reduce
vulnerability to seismic, wildfire,
wind, and other hazards.
FY 2025/26
Adopted
Budget
Municipal
Code
Regulatory Establishes local regulations
governing development, public
safety, nuisance abatement,
emergency management, and
municipal operations.
Provides regulatory authority to
implement mitigation-related
requirements and hazard
reduction measures.
Rancho
Cucamonga
Municipal
Code
Zoning
Ordinance /
Development
Code
Regulatory Establishes zoning districts,
land use standards,
development requirements,
and development review
procedures.
Reduces future hazard exposure
by directing development away
from hazard-prone areas and
implementing hazard-related
development standards.
Rancho
Cucamonga
Developme
nt Code
Planning
Department
Regulatory /
Plan
Administers land use planning,
development review, zoning
regulations, environmental
review, and implementation of
the General Plan.
Reduces future hazard exposure
through land-use planning,
development standards,
environmental review, and the
implementation of safety-related
policies.
FY 2025/26
Adopted
Budget
ReadyRC
Program
Education and
Outreach
City emergency preparedness
and public education program
that provides preparedness
information, alerts, and
emergency resources to
residents.
Promotes household
preparedness, public awareness,
evacuation readiness, and
disaster resilience.
EOP / City
Website
Healthy RC Education and
Outreach
Community health and
wellness initiative focused on
improving quality of life, public
health, and community
engagement.
Supports community resilience,
outreach to vulnerable
populations, and hazard
preparedness messaging.
General
Plan /
Budget
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TABLE 5-1. RANCHO CUCAMONGA CAPABILITIES ASSESSMENT
Capability
Name
Capability
Type Description Mitigation Relevance Source
Library
Services
Education and
Outreach
Provides educational
programming, public
information resources, internet
access, and community
gathering spaces.
Can serve as a location for
preparedness education, public
information dissemination, and
emergency communications.
FY 2025/26
Adopted
Budget
Community
Affairs /
Engagement
& Special
Programs
Education and
Outreach
Coordinates public outreach,
community engagement,
special events, and public
information campaigns.
Supports mitigation outreach, risk
communication, and public
participation in planning
processes.
FY 2025/26
Adopted
Budget
Community
Services
Department
Education and
Outreach
Provides recreation,
community programming,
senior services, and
community events.
Supports outreach to residents
and vulnerable populations before
and after disasters.
FY 2025/26
Adopted
Budget
Community
Outreach
and Support
Team
(COAST)
Education and
Outreach
The Community Outreach and
Support Team (COAST) is a
multidisciplinary partnership
involving the City, Rancho
Cucamonga Fire District, law
enforcement, behavioral health
professionals, and community
service providers. The program
conducts proactive outreach
and connects individuals
experiencing mental health,
behavioral health, or social
service needs with appropriate
resources and support
services.
Supports community resilience by
improving outreach to vulnerable
populations, enhancing access to
behavioral health and social
services, and strengthening the
City's ability to assist residents
before, during, and after
emergencies and disasters. The
program also helps build
relationships with populations that
may require additional support
during evacuations, sheltering
operations, and disaster recovery
efforts.
FY 2025/26
Adopted
Budget
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HAZARD MITIGATION STRATEGIES
Hazard Mitigation Goals
The goals identified in Chapter 1 help inform the development of policies to protect community members, ecosystems, and other important assets from hazard events.
These goals were developed to align with the City’s General Plan Safety Element, which plays an important role in risk reduction in Rancho Cucamonga. These goals informed the development of mitigation actions and act as checkpoints to help City staff determine implementation progress.
Evaluation of Potential Hazard Mitigation Actions
The Committee prepared a set of potential mitigation actions based on hazard profiles, threat and capability assessments, community survey results, discussions among Committee members, and existing best practices. Next, the Committee evaluated these potential actions using the following criteria:
• FEMA requires local governments to evaluate potential mitigation actions' monetary and non-monetary costs and benefits. While local governments are not required to assign specific dollar values to each action, they should identify the general size of costs and benefits. The Committee may elect to include measures with high costs or low benefits, but such measures should benefit the community and make appropriate use of local resources.
• FEMA also directs local governments to consider the following questions as part of the financial analysis:
o What is the frequency and severity of the hazard type to be addressed by the action, and how vulnerable is the community to this hazard? o What impacts of the hazard will the action reduce or avoid? o What benefits will the action provide to the community? The Committee also reviewed and revised the potential hazard mitigation actions using the STAPLE/E (Social, Technical, Administrative, Political, Legal, Economic, and Environmental) criteria (Table 5-2). The Committee did not formally assess every potential mitigation action under all STAPLE/E criteria but used the criteria to guide and inform the discussion. The Committee also discussed how the criteria might be used to evaluate grant applications that the City may submit to receive funding for LHMP implementation.
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TABLE 5-2. STAPLE/E CRITERIA
Issues Criteria
Social • Is the action socially acceptable to Rancho Cucamonga community members? • Would the action mistreat some individuals?
• Is there a reasonable chance of the action causing a social disruption? Technical • Is the action likely to reduce the risk of the hazard occurring, or will it reduce the hazard's effects?
• Will the action create new hazards or make existing hazards worse? • Is the action the most useful approach for Rancho Cucamonga to take, given the City and community members' goals?
Administrative • Does the City have the administrative capabilities to implement the action? • Are there existing City staff who can lead and coordinate the implementation of the measure, or can the City reasonably hire new staff for this role? • Does the City have enough staff, funding, technical support, and other resources to implement the action?
• Are there administrative barriers to implementing the action? Political • Is the action politically acceptable to City officials and other relevant jurisdictions and political entities?
• Do community members support the action?
Legal • Does the City have the legal authority to implement and enforce the action? • Are there potential legal barriers or consequences that could hinder or prevent the implementation of the action?
• Is there a reasonable chance that the implementation of the action would expose the City to legal liabilities?
• Could the action reasonably face other legal challenges? Economic • What are the monetary costs of the action, and do the costs exceed the monetary benefits?
• What are the start-up and maintenance costs of the action, including administrative costs?
• Has the funding for action implementation been secured, or is a potential funding source available?
• How will funding the action affect the City’s financial capabilities? • Could the implementation of the action reasonably burden the Rancho Cucamonga economy or tax base?
• Could there reasonably be other budgetary and revenue impacts to the City? Environmental • What are the potential environmental impacts of the action? • Will the action require environmental regulatory approvals? • Will the action comply with all applicable federal, state, regional, and local environmental regulations?
• Will the action reasonably affect any endangered, threatened, or otherwise sensitive species of concern?
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Previous Mitigation Action Progress
The City reviewed the mitigation actions included in the previous 2021 LHMP and incorporated applicable actions into the development of this Plan. Table 5-3 identifies the actions that were removed from the 2021 LHMP because they were completed by the City.
TABLE 5-3. PREVIOUSLY COMPLETED MITIGATION ACTIONS
2021 ID Mitigation Action Status
2026
Disposition
1.04 Identify City facilities that can serve as key cooling centers, evacuation sites, and shelter locations.
(Hazards addressed: All)
Completed
2025
Removed
1.11 Integrate policy direction and other information from this Plan into other City documents, including the
General Plan, Emergency Operations Plan, Capital
Improvements Program, Sustainability Plan, and
Healthy RC Strategic Plan. (Hazards addressed:
All)
Completed
2022
Removed
2.03 Improve local understanding of the threat of a major earthquake by conducting a citywide scenario
modeling potential loss of life and injuries,
destroyed and damaged structures, and
interruptions to key services.
Completed
2022
Removed
3.04 Evaluate a hillside weed abatement pilot program
using goats or other livestock to reduce fuel loads in
fire-prone areas.
Completed
2024
Removed
3.05 Prepare a Community Wildfire Protection Plan for
areas within the WUIFA and surrounding areas
north of Interstate 210.
Completed
2021
Removed
3.10 Coordinate RCFD and CVWDs' recommended
landscaping vegetation lists and design
recommendations that illustrate wildfire-resilient
strategies.
Completed
2024
Removed
Cost Estimates
To meet the cost estimation requirements of the hazard mitigation planning process, the Committee identified relative cost estimates based on their understanding of the mitigation action's intent and their experience developing identical or similar programs/implementing projects.
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Four cost categories based on the City’s typical cost criteria were used for budgeting purposes:
• Low cost ($): $100,000 or less
• Medium cost ($$): $100,001 to $499,999
• Medium-high cost ($$$): $500,000 to $999,999
• High cost ($$$): Greater than $1,000,000
Based on the criteria and evaluation processes used during Plan development, the Committee prepared a prioritized list of mitigation actions to improve Rancho Cucamonga’s resilience to hazard events. Table 5-4 lists the mitigation actions, their prioritization, and other implementation details. In addition to mitigation action and strategies, several “Preparedness Activities” were identified and denoted with a letter “P.”
High-priority actions were generally those that address high-risk hazards, protect critical facilities and vulnerable populations, support multiple hazard types, and can be implemented using available resources or potential grant funding opportunities.
Timeframes
Hazard mitigation planning requires the City to identify general timing durations for mitigation actions. The following timeframes are used as defined below:
• Short-Term is a mitigation action anticipated to be completed in 1–2 years. • Mid-Term is a mitigation action anticipated to be completed in 3–5 years. • Long-Term is a mitigation action anticipated to be completed in 5 years or more.
• Ongoing (Annually): These actions are the type that City staff would conduct annually.
• Ongoing (As Needed): The actions are activities that City staff would conduct in response to a request by internal (City Departments) or external (Property Owners) forces.
• Future Planning Process: These actions are considered low-priority actions that the City would like to continue to track but does not feel they would be able to implement in the current planning implementation timeframe.
For actions that use these terms, the intent is to indicate that the action may add to existing capabilities, may not have a particular start or end date, and may occur periodically. This is typically used for actions that include new policies, tasks, or
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 172
standard operating procedures intended to mitigate future risks. If a single year is stated in the timeframe column, this indicates the year the action will begin.
Prioritization
As part of the development and review of mitigation actions, the Committee also prioritized them. The prioritization efforts considered the risks and threats associated with each hazard, financial costs and benefits, technical feasibility, and community values. Committee members were asked to identify their priority actions through a voting exercise. Items are prioritized based on the number of votes received by the Committee members. These quantitative scores were then converted into qualitative categories:
low, medium, and high priority.
2026 HAZARD MITIGATION ACTIONS
Based on the criteria and evaluation processes used during Plan development, the Committee prepared a prioritized list of mitigation actions to improve Rancho Cucamonga’s resilience to hazard events (Table 5-4). These actions collectively form Rancho Cucamonga’s hazard mitigation strategy. During preparation of this update, the HMPC recognized areas where new actions were necessary. To support this process, the HMPC developed new mitigation strategies and actions (identified in blue) to support the risks and vulnerabilities to these hazards. During this process, the only actions that were not included were those that the City did not have direct control over or were deemed infeasible based on STAPLE/E criteria. As an example, the City recognized that their proximity to the Ontario International Airport increased risk to parts of the City, however there is very little the City can do to manage that risk because the facility is located in an adjacent City and oversight of the airport is undertaken by the Federal Aviation Administration.
The list of actions also includes preparedness activities that are intended to improve emergency response for the City and community members when hazard events occur or are imminent. Although these actions are not considered mitigation activities, they are expected to decrease the harm the community faces from hazard events and support the same goals as mitigation actions.
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 173
TABLE 5-4: RANCHO CUCAMONGA MITIGATION ACTIONS IMPLEMENTATION PLAN 2026 ID Mitigation Action Item
Potential Funding
Sources1
Responsible
Departments2
Relative
Cost3
Time
Frame Priority4
Emergency Preparedness Activities
P1 Conduct regular emergency preparedness drills
and training exercises for City staff.
General Fund,
Other Grants
RCFD $ Ongoing
(Annual)
N/A
P2 Continue to support the expansion of Red Cross
Agreements with public agencies (City, School
Districts) and private entities (Faith-Based
Organizations, etc.) to ensure that facilities can
act as evacuation sites during major emergencies.
General Fund,
Other Grants
CSD, RCFD $ Ongoing
(AsNeeded)
N/A
P3 Continue working with local businesses and
organizations to conduct regular workplace
emergency preparedness training.
General Fund,
Other Grants
RCFD $ Ongoing
(AsNeeded)
N/A
P4 Expand participation in the Rancho Cucamonga
ReadyRC program for residents and businesses.
General Fund,
Other Grants
RCFD $ Mid-Term N/A
P5 Develop means to evacuate community members
who do not have access to private vehicles or are
otherwise unable to drive.
General Fund,
Other Grants
RCFD $ Short Term N/A
P6 Collaborate with the equestrian community in the
City to ensure effective staging, evacuation, and
sheltering plans for large animals.
General Fund,
Other Grants
RCFD $ Ongoing
(Annually)
N/A
P7 Continue to ensure effective emergency
notifications through multiple media formats—in at
least English and Spanish—about pending,
imminent, or ongoing emergency events. Ensure
that information is accessible to persons with
disabilities and functional needs.
General Fund,
Other Grants
RCFD $ Ongoing
(Annually)
N/A
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 174
TABLE 5-4: RANCHO CUCAMONGA MITIGATION ACTIONS IMPLEMENTATION PLAN 2026 ID Mitigation Action Item
Potential Funding
Sources1
Responsible
Departments2
Relative
Cost3
Time
Frame Priority4
P8 Continue to update and maintain the Rancho
Cucamonga Emergency Operations Plan (last
updated in 2023, next scheduled update is in
2028).
General Fund,
Other Grants
RCFD $ Mid-Term N/A
P9 Continuously update response procedures for
first-responder departments to effectively address
emerging hazard events.
General Fund,
Other Grants
RCFD $ Ongoing
(As
Needed)
N/A
P10 Ensure that the City has an adequate supply of
sandbags for residents and businesses, including
prefilled sandbags for individuals who may not be
able to fill them independently.
General Fund,
Other Grants
RCFD $ Ongoing
(Annually)
N/A
P11 Continue conducting active shooter drills for City
staff by the Police Department and Fire District
tactical teams.
General Fund,
Other Grants
PD $ Ongoing
(Annually)
N/A
P12 Continue supporting community active shooter
preparedness through quarterly Active Shooter
educational workshops.
General Fund,
Other Grants
PD $ Ongoing
(As
Needed)
N/A
P13 Increase the number of City staff who have
CalOES Safety Assessment Program (SAP)
credentials.
General Fund,
Other Grants
B&S $ Mid-Term N/A
Multiple Hazards
1.01 Explore the feasibility of connecting critical
facilities (e.g., the Civic Center, key community
centers, and fire stations) to a microgrid power
supply network.
(Hazards addressed: All)
General Fund,
BRIC/HMGP
Grants, Other
Grants
CMO, CSD,
PW, B&S,
RCFD, ENG,
RCMU
$$ Long-Term Medium
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 175
TABLE 5-4: RANCHO CUCAMONGA MITIGATION ACTIONS IMPLEMENTATION PLAN 2026 ID Mitigation Action Item
Potential Funding
Sources1
Responsible
Departments2
Relative
Cost3
Time
Frame Priority4
1.02 Upgrade or install energy-efficient fixtures,
appliances, and/or equipment within Critical
Facilities to extend the fuel supply for backup
generators.
(Hazards addressed: All)
General Fund,
BRIC/HMGP
Grants, Other
Grants
PW, RCMU,
CMO, B&S
$$$ Long-Term Low
1.03 Repair, as feasible, all major deficiencies
identified during inspections to prevent collapse,
failure, or damage to key infrastructure in the
event of a natural disaster.
(Hazards addressed: All)
General Fund,
BRIC/HMGP
Grants, Other
Grants
PW, B&S, CMO,
ENG
$$$ Ongoing
(As
Needed)
High
1.04 Conduct a feasibility assessment for the
installation of alternative energy (solar, fuel cell,
battery backup, etc.) at key critical facilities within the City. Ensure current and future facilities can
be used as shelters and cooling centers.
(Hazards addressed: All)
General Fund,
BRIC/HMGP
Grants, Other
Grants
CMO, PW, B&S,
ENG
$ Mid-Term Low
1.05 Work closely with community groups to increase
awareness of hazard events and resiliency
opportunities among socially vulnerable
community members. (Partnership with Healthy
RC and Ready RC)(Hazards addressed: All)
General Fund,
BRIC/HMGP
Grants, Other
Grants
CMO, PW, B&S,
ENG
$ Ongoing
(Annually)
High
1.06 Avoid building new City-owned key facilities in
mapped hazard areas. If no feasible sites outside
of mapped areas exist, ensure that such facilities
are hardened against hazards beyond any
minimum building requirements/mitigation
standards.
(Hazards addressed: All)
General Fund,
BRIC/HMGP
Grants, Other
Grants
PLAN, ENG $ Ongoing
(As
Needed)
Low
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 176
TABLE 5-4: RANCHO CUCAMONGA MITIGATION ACTIONS IMPLEMENTATION PLAN 2026 ID Mitigation Action Item
Potential Funding
Sources1
Responsible
Departments2
Relative
Cost3
Time
Frame Priority4
1.07 Coordinate with regional social service agencies
and nonprofit care providers to obtain temporary
shelter for homeless persons in advance of
potential hazard events.
(Hazards addressed: All)
General Fund,
BRIC/HMGP
Grants, Other
Grants
CMO $ Ongoing
(As
Needed)
Low
1.08 Coordinate with Caltrans to monitor bridges within the City and develop recommendations for
upgrade/retrofit when deemed necessary.
Prioritize upgrades/retrofits on key evacuation
routes.
(Hazards addressed: All)
General Fund,
BRIC/HMGP
Grants, Other
Grants
ENG $ Ongoing
(Annually)
Medium
1.09 Closely monitor changes in the boundaries of
mapped hazard areas resulting from land-use
changes, new or updated information, changes to
state or federal hazard maps, or climate change,
and adopt new mitigation actions or revise
existing ones to ensure continued resiliency.
(Hazards addressed: All)
General Fund,
BRIC/HMGP
Grants, Other
Grants
PLAN, GIS $ Ongoing
(As
Needed)
Low
1.10 Install and harden an emergency powergeneration system at Central Park that the City can use as an evacuation site.
General Fund,
BRIC/HMGP
Grants, Other
Grants
PW, ENG,
RCFD, B&S,
CSD
$$$ Short Term High
1.11 Develop a Climate Resiliency Strategy that
enhances existing efforts within the City and
analyzes changing climatic conditions that may
impact public health, natural resources, the built
environment, and socioeconomic vulnerability.
General Fund,
BRIC/HMGP
Grants, Other
Grants
CMO $$ Mid-Term Low
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 177
TABLE 5-4: RANCHO CUCAMONGA MITIGATION ACTIONS IMPLEMENTATION PLAN 2026 ID Mitigation Action Item
Potential Funding
Sources1
Responsible
Departments2
Relative
Cost3
Time
Frame Priority4
1.12 (New)
Develop a Point of Distribution Plan that supports
ongoing operations during severe weather
incidents and improves coordination during larger
incidents (wildfire, earthquake, power failure)
General Fund,
BRIC/HMGP
Grants, Other
Grants
CMO, CSD,
PW, B&S,
RCFD, ENG,
RCMU
$$ Short-Term Medium
Seismic Hazards
2.01 Monitor and track development applications
proposing seismic improvements and ancillary
measures to accommodate changes to the
structure's original use.
General Fund,
BRIC/HMGP
Grants, Other
Grants
B&S $ Ongoing
(As
Needed)
Medium
2.02 Expand education and outreach by community
groups and industry representatives to residents
and businesses to obtain earthquake insurance.
General Fund,
BRIC/HMGP
Grants, Other
Grants
RCFD, B&S $ Ongoing
(As
Needed)
Medium
2.03 Retrofit critical facilities with seismically rated window film treatments to prevent glass windows
from shattering and install tie-downs and straps
for fixtures inside buildings.
General Fund,
BRIC/HMGP
Grants, Other
Grants
PW $$$ 2030
Mid-Term
Medium
2.04 Collaborate with CVWD to monitor groundwater
elevations for potential liquefaction areas to
ensure shallow groundwater conditions do not
increase seismic vulnerability.
General Fund,
BRIC/HMGP
Grants, Other
Grants
ENG $ Ongoing
(Annually)
Medium
Wildfire
3.01 Promote the proper maintenance and separation
of power lines.
General Fund,
BRIC/HMGP
Grants, Other
Grants
RCFD $ Ongoing
(Annually)
Medium
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 178
TABLE 5-4: RANCHO CUCAMONGA MITIGATION ACTIONS IMPLEMENTATION PLAN 2026 ID Mitigation Action Item
Potential Funding
Sources1
Responsible
Departments2
Relative
Cost3
Time
Frame Priority4
3.02 Promote the efficient response to fallen power
lines.
General Fund,
BRIC/HMGP
Grants, Other
Grants
RCFD $ Ongoing
(As
Needed)
Low
3.03 Coordinate with private entities to reduce highly
flammable vegetation in the developed portions of
the Wildland Urban Interface Fire Area (WUIFA)
and replant with fire-resistant species.
General Fund,
BRIC/HMGP
Grants, Other
Grants
RCFD $ Ongoing
(Annually)
High
3.04 Work with property owners to manage dead
vegetation within flood-control facility footprints,
railroad rights-of-way, parks, and open spaces,
especially during and after drought episodes.
General Fund,
BRIC/HMGP
Grants, Other
Grants
RCFD, PW $ Ongoing
(Annually)
Medium
3.05 Continue fire-hazard prevention awareness
campaigns for residents in the WUIFA and
surrounding areas.
General Fund,
BRIC/HMGP
Grants, Other
Grants
RCFD $ Ongoing
(Annually)
Medium
3.06 Require all new development in the WUIFA and
surrounding areas to use building materials and
methods approved by the CA Building Standards
Commission and establish zones of defensible
space around structures in these areas.
General Fund,
BRIC/HMGP
Grants, Other
Grants
RCFD, B&S $ Ongoing
(As
Needed)
Medium
3.07 Update Chapter 17.80, Tree Preservation, of the
Municipal Code to allow the removal and
modification of eucalyptus windrows in the WUIFA
or in areas with heightened wildfire susceptibility.
General Fund,
BRIC/HMGP
Grants, Other
Grants
PLAN, RCFD $ Mid-Term Low
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 179
TABLE 5-4: RANCHO CUCAMONGA MITIGATION ACTIONS IMPLEMENTATION PLAN 2026 ID Mitigation Action Item
Potential Funding
Sources1
Responsible
Departments2
Relative
Cost3
Time
Frame Priority4
3.08 Work with partners to better manage safe and
equitable access to the National Forest via routes
through Cucamonga Canyon and the Etiwanda
Preserve, while ensuring fire safety in surrounding
areas.
General Fund,
BRIC/HMGP
Grants, Other
Grants
RCFD, PLAN $ Ongoing
(As
Needed)
Medium
3.09 (New)
Implement and manage a wildfire camera network
in the northern foothills to provide first responders
and residents with critical early warnings,
accelerating response times and evacuations. (2
phases completed in 2026, remaining to be
completed)
General Fund,
BRIC/HMGP
Grants, Other
Grants
RCFD $$$$ 2029
Mid-Term
High
3.10 (New)
To reduce wildfire response times and enhance
suppression capabilities, the Fire District shall
establish and maintain permanent, high-capacity
water sources for helicopters (e.g., aerial dip
sites) at identified strategic locations along the
Wildland-Urban Interface (WUI).
General Fund,
BRIC/HMGP
Grants, Other
Grants
RCFD $$ 2027
Short Term
High
Flood
4.01 Investigate the use of permeable paved and
landscaped swales for new construction and
replacement of City-owned hardscape areas.
General Fund,
BRIC/HMGP/FMA
Grants, Other
Grants
PW, PLAN,
ENG
$ Long Term Low
4.02 Update the City’s Storm Drain Master Plan
periodically (in conjunction with the LHMP and
CIP) to incorporate new data and/or address
emerging issues.
General Fund,
BRIC/HMGP/FMA
Grants, Other
Grants
ENG $$ 2027
Short Term
High
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 180
TABLE 5-4: RANCHO CUCAMONGA MITIGATION ACTIONS IMPLEMENTATION PLAN 2026 ID Mitigation Action Item
Potential Funding
Sources1
Responsible
Departments2
Relative
Cost3
Time
Frame Priority4
4.03 Analyze whether new critical facilities can be built at least 1 foot above the anticipated 500-year
flood elevation to determine where this is feasible.
General Fund,
BRIC/HMGP/FMA
Grants, Other
Grants
ENG $$ Long Term Low
4.04 Coordinate with dam owners/operators, state, and
federal agencies to collectively identify threats to
the City and the region and identify ways to
retrofit/strengthen the dams under their control.
General Fund,
BRIC/HMGP/FMA
Grants, Other
Grants
RCFD, ENG $ Ongoing
(Annually)
Medium
4.05 Identify potential flood improvements that also
reduce the threat to dam failure and/or inundation.
General Fund,
BRIC/HMGP/FMA
Grants, Other
Grants
ENG $ Ongoing
(As
Needed)
Medium
Severe Weather
5.01 Update Chapter 17.56 of the Rancho Cucamonga
Municipal Code to reflect the latest advances in
best practices in landscape design that reduce
water use within the City while also addressing
wildfire susceptibility.
(Hazards addressed: Drought)
General Fund,
BRIC/HMGP
Grants, Other
Grants
PLAN, RCFD $ Mid-Term Medium
5.02 Develop a campaign to encourage water/energy
efficiency and reduce consumption in existing
development, and to promote the expansion of
electric-vehicle-ready construction in new
development.(Hazards addressed: Drought,
Extreme Heat)
General Fund,
BRIC/HMGP
Grants, Other
Grants
CMO, B&S $ 2027
Short Term
Medium
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 181
TABLE 5-4: RANCHO CUCAMONGA MITIGATION ACTIONS IMPLEMENTATION PLAN 2026 ID Mitigation Action Item
Potential Funding
Sources1
Responsible
Departments2
Relative
Cost3
Time
Frame Priority4
5.03 Use drought-tolerant plants when installing new or retrofitting City-owned landscapes. Limit turf that
is not drought-tolerant to recreational fields and
lawns, and only when no feasible drought-tolerant
alternatives exist.
(Hazards addressed: Drought)
General Fund,
BRIC/HMGP
Grants, Other
Grants
PW $$ Ongoing
(As
Needed)
Medium
5.04 Implement an Urban Forest Master Plan to
diversify tree ages, increase resilience to drought
and warmer temperatures, and expand shaded
areas in the City to reduce the urban heat island
effect.
(Hazards addressed: Extreme Heat)
General Fund,
BRIC/HMGP
Grants, Other
Grants
PW, PLAN $$ Mid-Term High
5.05 Create a Cooling Center Plan to use designated
public facilities (libraries, community centers, etc.)
as cooling centers for vulnerable populations
during extreme weather events.
(Hazards addressed: Extreme Heat)
General Fund,
BRIC/HMGP
Grants, Other
Grants
RCFD, CSD $ Short Term
2028
High
5.06 Promote passive cooling design (brise-soleil, long roof overhangs, locating windows away from
southern facades, etc.) in new developments
during the design review process.
(Hazards addressed: Extreme Heat)
General Fund,
BRIC/HMGP
Grants, Other
Grants
B&S, PLAN $ Ongoing
(As
Needed)
High
5.07 Evaluate the equitable access and long-term
capacity of designated cooling centers and
shelters in the City to provide sufficient relief from
extreme heat. Assess the need to expand
services as the frequency, duration, and severity
of future heat waves may change due to climate
change.
(Hazards addressed: Extreme Heat)
General Fund,
BRIC/HMGP
Grants, Other
Grants
CMO, RCFD,
CSD
$ Mid-Term Medium
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 182
TABLE 5-4: RANCHO CUCAMONGA MITIGATION ACTIONS IMPLEMENTATION PLAN 2026 ID Mitigation Action Item
Potential Funding
Sources1
Responsible
Departments2
Relative
Cost3
Time
Frame Priority4
5.08 Conduct outreach to residents and businesses
prior to the severe winds (Santa Ana Wind
events) on proper tree maintenance and
identification of potentially hazardous trees.
(Hazards addressed: Severe Wind)
General Fund,
BRIC/HMGP
Grants, Other
Grants
RCFD, CMO $ Ongoing
(As
Needed)
Low
5.09 Increase the use and construction of shade
structures within new developments, City facilities,
parks, and trails to reduce urban heat island
impacts.
(Hazards addressed: Extreme Heat)
General Fund,
BRIC/HMGP
Grants, Other
Grants
PLAN, All
Departments
$$ - $$$ Ongoing
(As
Needed)
Low
5.10 Expand access to alternative energy
technologies, energy-efficiency improvements,
and appliances, and to programs for vulnerable
populations, to reduce energy consumption and
the need for City services during extreme heat
conditions.
(Hazards addressed: Energy-Shortage, Extreme
Heat)
General Fund,
BRIC/HMGP
Grants, Other
Grants
CMO, B&S $ Ongoing
(As
Needed)
Medium
Human-Caused Hazards
6.01 Coordinate with the San Bernardino County
Sheriff to monitor potential incidents resulting in
terrorism and mass casualty incidents.
(Hazards addressed: Terrorism/Mass Casualty
Incidents)
General Fund,
Other Grants
PD $ Ongoing
(As
Needed)
High
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 183
TABLE 5-4: RANCHO CUCAMONGA MITIGATION ACTIONS IMPLEMENTATION PLAN 2026 ID Mitigation Action Item
Potential Funding
Sources1
Responsible
Departments2
Relative
Cost3
Time
Frame Priority4
6.02 Disseminate information on cyber threats or
potential terrorist activity to City staff and
continually follow up with information on further
developments on the situation.
(Hazards addressed: Terrorism/Mass Casualty
Incidents, Cyber Threats)
General Fund,
Other Grants
DoIT, PD $ Ongoing
(As
Needed)
Medium
6.03 Regularly update cybersecurity software and
educate business owners and residents on
current internet-based threats.
(Hazards addressed: Cyber Threats)
General Fund,
Other Grants
DoIT, PD $ Ongoing
(As
Needed)
Medium
6.04 Evaluate all critical facilities, City administration buildings, and other buildings the City may deem
important in the future for counterterrorism design
elements and building materials.(Hazards
addressed: Terrorism/Mass Casualty Incidents)
General Fund,
Other Grants
PD, All
Departments
$$ Mid-Term High
6.05 Coordinate and enhance datasets for schools,
hospitals, and other critical facilities with the
School District, Hospitals, and other key entities
within the City to better respond to mass-casualty
and terrorism incidents.
(Hazards addressed: Terrorism/Mass Casualty
Incidents)
General Fund,
Other Grants
PD, RCFD $ Ongoing
(As
Needed)
Medium
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 184
TABLE 5-4: RANCHO CUCAMONGA MITIGATION ACTIONS IMPLEMENTATION PLAN 2026 ID Mitigation Action Item
Potential Funding
Sources1
Responsible
Departments2
Relative
Cost3
Time
Frame Priority4
Hazardous Materials Release
7.01 Discourage new sensitive land uses, including
schools, parks, childcare centers, adult and senior
assisted living facilities, and community centers,
from locating near identified hazardous material
facilities. Discourage or prohibit new hazardous
material facilities from locating near sensitive land
uses.
General Fund,
BRIC/HMGP
Grants, Other
Grants
PLAN, B&S $ Ongoing
(As
Needed)
High
7.02 Continuously inspect businesses and other
properties that store hazardous materials and
create an inventory of storage locations requiring
updates, maintenance, or renovation.
General Fund,
BRIC/HMGP
Grants, Other
Grants
RCFD $ Ongoing
(Annually)
High
7.03 Coordinate regularly with hazardous materials
generators/operators (So Cal Gas, Edison, etc.) to
understand operational changes within the City.
General Fund,
BRIC/HMGP
Grants, Other
Grants
ENG, RCFD $ Ongoing
(As
Needed)
Medium
Aircraft Incident
8.01 Coordinate with the Federal Aviation
Administration on flight paths over the City and
potential changes that may increase vulnerability
to aircraft incidents. (Hazards addressed: Aircraft
Incidents)
General Fund,
Other Grants
RCFD $ Ongoing
(As
Needed)
Low
Power Failure / Energy Shortage
9.01 (New)
Identify new energy sources and demand
management strategies to offset potential energy
shortages in the future
General Fund,
BRIC/HMGP
Grants, Other
Grants
RCMU $ Mid-Term Medium
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 185
TABLE 5-4: RANCHO CUCAMONGA MITIGATION ACTIONS IMPLEMENTATION PLAN 2026 ID Mitigation Action Item
Potential Funding
Sources1
Responsible
Departments2
Relative
Cost3
Time
Frame Priority4
9.02 (New)
Retrofit critical facilities to incorporate alternative energy sources and backup power supplies to
increase resilience from power outages
General Fund,
BRIC/HMGP
Grants, Other
Grants
RCMU $$$$ Long Term Medium
1 Building Resilient Infrastructure and Communities (BRIC) | Hazard Mitigation Grant Program (HMGP) | Flood Mitigation Assistance (FMA) 2 Rancho Cucamonga Fire District (RCFD) | Community Services (CSD) | Building and Safety (B&S) | Rancho Cucamonga Municipal Utility (RCMU) | City Manager's Office (CMO) | Police Department (PD) | Planning (PLAN) | Engineering (ENG) | Public Works (PW) | Geographic Information Systems (GIS) | Department of Information Technology (DoIT) | Bold text denotes primary responsible department. 3 Relative Cost Categories: $ Less than $100,000 | $$ $100,001 to $499,999 | $$$ $500,000 to $999,999 | $$$$ Greater than $1,000,000 4 Priority: All medium and high-priority actions anticipated for completion within the next five years should work with Engineering and incorporate into the Major Projects Capital Program.
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga 186
NATIONAL FLOOD INSURANCE PROGRAM
Rancho Cucamonga participates in the National Flood Insurance Program (NFIP), created by Congress in 1968 to provide subsidized flood insurance to homeowners in flood-prone areas. Rancho Cucamonga has participated in NFIP since September 1984.80
Although participation is not a dedicated hazard mitigation action, Rancho Cucamonga will continue to participate in the NFIP and comply with the program’s requirements by enforcing the City’s Floodplain Management Regulations.81 This regulation applies to all areas identified as flood-prone within the City. This chapter of the Municipal Code identifies the purpose of the regulation, methods of reducing flood losses, the basis for establishing flood hazard areas, development permit requirements, duties and responsibilities of the City’s Floodplain Administrator (City Engineer), development standards that apply in flood-prone areas, and required documentation and analysis for construction within these areas. As part of the City’s efforts to comply with NFIP, Rancho Cucamonga will update and revise the Floodplain Management regulations to minimize the risk of harm from flood events. These updates and revisions may be promoted by changes in local demographics, shifts in land use, changes to flood regimes, such as frequency and intensity of flood events, and other factors that may warrant municipal action. The City will also continue to incorporate any changes to the locations and designations of mapped floodplains into future planning documents, including updates to this Plan.
Repetitive Loss Properties
According to FEMA, the document contains Special Flood Hazard Areas, including 157 policies in force. Total insurance coverage for these policies amounts to $43,301,900.
No Severe Repetitive Loss properties exist within the City; one Repetitive Loss property has been identified and remains unmitigated as of 2025. This property is located outside of the Special Flood Hazard Area (SFHA). Between 1979 and 2019, a total of 24 payments were made for flood insurance loss claims, ranging from approximately $50 to $18,000, with an average payment of $4,500. 80 Community Status Book Report – California: Communities Participating in the National Flood Program. https://www.fema.gov/cis/CA.pdf
81 Rancho Cucamonga Municipal Code. Title 19 Environmental Protection, 19.2 Floodplain Management Regulations. http://qcode.us/codes/ranchocucamonga/
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CHAPTER 6 –
PLAN MAINTENANCE
For this LHMP to remain effective and useful to the Rancho Cucamonga community, it must remain up to date. An updated version of the LHMP will continue to guide Rancho Cucamonga’s hazard mitigation activities and help keep the City eligible for state and federal hazard mitigation funding. The Committee has structured this LHMP so individual sections can easily be updated as new information becomes available and new needs arise, helping to keep this Plan current.
This chapter discusses updating this Plan to comply with applicable state and federal requirements. This chapter also describes how the City can incorporate the mitigation actions described in Chapter 5 into existing programs and planning mechanisms and how public participation will remain an important part of Plan monitoring and future update activities.
COORDINATING BODY
The Committee will remain responsible for maintaining and updating the Plan, including evaluating the Plan's effectiveness as needed. Members of the Committee will also coordinate the Plan's implementation through their respective positions. Table 1-1 in Chapter 1 lists current members. In future years, staff and representatives (either current Committee members or other individuals) from the following departments, districts, and agencies should be included in maintenance and update activities:
• Building and Safety Services
• City Clerk
• City Manager’s Office
• Community Improvement
• Community Outreach and Support Team (COAST)
• Community Services
• Department of Innovation and Technology
• Engineering Services
• Financial Management and Strategic Planning
• Fire District
• Human Resources
• Planning
• Police/Sheriff
• Public Works Services
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• Transportation
The staff member currently serving as the Committee leader (the person responsible for coordinating future updates) is in the Fire District. The Committee leader will serve as the project manager during the update process or may designate another staff member to fulfill this role. The Committee leader or their designee will coordinate maintenance of this Plan, lead the formal Plan review and evaluation activities, direct the Plan update, and assign tasks to other members of the Committee to complete these activities. Such tasks may include collecting data, developing or updating mitigation actions, making presentations to City staff and community groups, and revising the Plan sections.
PLAN IMPLEMENTATION
The Plan's effectiveness depends on the successful implementation of the mitigation actions. Implementation includes integrating mitigation actions into existing City plans, policies, programs, and other implementation mechanisms. The mitigation actions in this Plan are intended to reduce the damage from hazard events, help the City secure funding, and provide a framework for hazard mitigation activities. Committee members prioritized the hazard mitigation actions in Table 5-4 in Chapter 5. These priorities will guide the implementation of these actions through new or existing City mechanisms as resources are available. The LHMP project manager is responsible for overseeing the implementation, promotion, and maintenance of this Plan and facilitating meetings and coordinating activities related to Plan implementation and maintenance.
The key City Plans that shall incorporate content from this LHMP include:
• Rancho Cucamonga General Plan Safety Element: This element should incorporate relevant mapping and analysis in the Safety Element to ensure this plan's goals and policies are reinforced throughout future developments and projects proposed within the City.
• Rancho Cucamonga Emergency Operations Plan: The EOP focuses on the effective preparedness and response to hazard events that occur within the City. Incorporating relevant content from this plan into the EOP ensures consistency regarding the hazards addressed in both plans. • Rancho Cucamonga Capital Improvements Program: The CIP identifies key infrastructure investments throughout the City that may include hazard mitigation elements. Incorporating this plan into the CIP may assist with enhancing infrastructure investment through additional funding and/or modification of improvements to include hazard mitigation elements.
This integration of the LHMP into the Rancho Cucamonga General Plan also allows the City to comply with AB 2140 requirements, as identified in Chapter 1 of this plan.
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PLAN MAINTENANCE PROCESS
The City’s plan maintenance process will rely on the Rancho Cucamonga Mitigation Implementation Handbook, located in Appendix D. This handbook is intended to serve as a stand-alone document that provides concise, accessible guidance to staff on implementing and maintaining the Plan. A key component of the handbook is the specific mechanisms that the City and Fire District can use to integrate this plan into the other City planning mechanisms.
Plan Monitoring and Evaluation
When members of the Committee are not updating the Plan, they shall meet at least once a year to review implementation of mitigation actions and evaluate the Plan’s effectiveness. These meetings will include:
• Discussion of the timing of mitigation action implementation • Mitigation action implementation evaluation and determination of success • Mitigation action prioritization revisions, if deemed necessary • Mitigation action integration into other mechanisms, as needed The first annual review meeting should be conducted within one year of adoption of this Plan and continue annually thereafter. To the extent possible, Committee meetings should be scheduled at an appropriate time in the City’s annual budgeting process to help ensure that funding and staffing needs for mitigation actions are considered.
When the Committee meets to evaluate the Plan, the following questions will be asked:
• What hazard events, if any, have occurred in Rancho Cucamonga in the past year? What were the impacts of these events on the community? Were the impacts mitigated, and if so, how?
• What mitigation actions have been successfully implemented? Have any mitigation actions been implemented but not successfully? If so, why? • What mitigation actions, if any, have been scheduled for implementation but have not yet been implemented?
• What is the schedule for implementing future mitigation actions? Is this schedule reasonable? Does the schedule need to be adjusted for future implementation, and are such adjustments appropriate and feasible? • Have any new concerns arisen, including hazard events in other communities or regions not covered by existing mitigation actions?
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• Is new data available to inform the Plan's updates, including data relevant to the hazard profiles and threat assessments?
• Are there any new planning programs, funding sources, or other mechanisms to support hazard mitigation activities in Rancho Cucamonga? Plan Updates
The information in this Plan, including the hazard profiles, threat assessments, and mitigation actions, is based on the best available information, practices, technology, and methods available to the City and Committee at the time this Plan was prepared. As factors change, including technologies, community demographics and characteristics, best practices, and hazard conditions, it is necessary to update the Plan to remain relevant. Additionally, Title 44, Section 201.6(d)(3) of the Code of Federal Regulations requires that LHMPs be reviewed, revised, and resubmitted for approval every five years to remain eligible for federal benefits.
Update Method and Schedule
The update process should begin no later than four years after this Plan is adopted, allowing a year for the update process before the Plan expires. The LHMP project manager or their designee may also choose to begin the update process sooner, depending on the circumstances. Some reasons for accelerating the update process may include:
• A presidential disaster declaration for Rancho Cucamonga or an area that includes part of or the entire City
• A hazard event that results in one or more fatalities in Rancho Cucamonga • Significant changes to hazard conditions, regulatory requirements, or community demographics
The update process will add new and updated methods, demographic data, community information, hazard data and events, considerations for threat assessments, mitigation actions, and other necessary information, keeping the Plan relevant and current. The Committee will determine the best process for updating the Plan, which should include the following steps:
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Update Adoption
The Rancho Cucamonga City Council is responsible for adopting this Plan and all future updates. As previously mentioned, adoption should occur every five years. To ensure the Plan remains active, the City should begin the update process at least one year before expiration. If the City has a grant application that relies on the LHMP, the Plan should be updated no later than 18 months before expiration. Adoption should take place after FEMA notifies the City that the Plan is Approved Pending Adoption. Once the City Council adopts the Plan following FEMA's approval, the adopted plan should be transmitted to FEMA.
Continued Public Involvement
The City will continue to keep the public informed about the Committee’s actions to review and update the LHMP. The Committee will develop a revised community engagement strategy that reflects the City’s updated needs and capabilities. The updated strategy should include a tentative schedule and plan for public meetings, recommendations for using the City's website and print and digital outreach tools for public outreach documentation. Outreach efforts should seek participation from underserved populations, people with access and functional needs, community-based organizations, businesses, schools, and other stakeholders that may be disproportionately impacted by hazards. The Committee will also distribute information Engage the Hazard
Mitigation Planning
Committee (with at least one
member from each City
department).
Contact non-City
organizations (that previously
participated or are interested
stakeholders) to participate in
the update.
Review and update the
hazard mapping and threat
assessment for critical
facilities.
Revise the threat
assessment for populations
and other assets.
Determine what measures
have been completed,
changed, cancelled, or
postponed and review and
revise mitigation actions, as
needed.
Prepare an updated plan to
be distributed to stakeholders
and the public.
Conduct a public review
period of the Draft Plan
allowing residents and
interested stakeholders to
provide comment.
Following public review, send
a draft of the updated plan to
Cal OES and FEMA for
review and approval.
Adopt the final updated Plan
within one year of beginning
the update process and
within five years of the
adoption of the previous
Plan.
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annually through the most appropriate method to ensure the widest dissemination to residents and businesses. These updates are anticipated to occur after the City conducts its annual Committee meeting.
POINT OF CONTACT
The Hazard Mitigation Planning Committee leader for Rancho Cucamonga is the primary point of contact for this Plan and future updates. At the time of writing, the Committee leader is Riley Davis, available at [email protected] or 1-909-477-2770.
Should staffing changes occur, responsibility for Plan maintenance, implementation, and future updates shall transfer to the individual designated by the Rancho Cucamonga Fire District to serve as the Committee leader.
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APPENDIX A –
HMPC MEETING MATERIALS
HMPC MEETING ACTIVITIES
Outreach Activity Date Materials
HMPC Meeting #1* February 25, 2026 Invites, Sign-in Sheets/Attendance, Agenda, Presentation
HPMC Meeting #2* May 12, 2026 Invites, Sign-in Sheets/Attendance, Agenda *see Chapter 1 for meeting descriptions
HMPC MEETING 1 MATERIALS
Agency Invite
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Email Invite
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Sign-In Sheets
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Online Attendance
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Meeting Agenda
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Presentation
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HMPC MEETING 2 MATERIALS
Agency Invite
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Sign-In Sheets
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Meeting Agenda
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APPENDIX B –
OUTREACH AND ENGAGEMENT
MATERIALS
OUTREACH AND ENGAGEMENT ACTIVITIES
Outreach Activity Date Materials
Stakeholder Meeting April 17, 2026 Sign-In Sheets, Agenda, Presentation
Community Arts Festival Outreach Booth April 18, 2026 Sign-In Sheets Public Hazard Mitigation Survey
(advertised via postcards and outreach events)
Spring 2026 Website
City Employee Survey Distribution
(sent via City email)
May 2026 Email
STAKEHOLDER MEETING MATERIALS
Sign-In Sheets
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Meeting Agenda
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Presentation
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COMMUNITY ARTS FESTIVAL OUTREACH
BOOTH MATERIALS
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CITY EMPLOYEE SURVEY DISTRIBUTION
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PUBLIC HAZARD MITIGATION SURVEY
Postcard Advertisement
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Website Advertisement
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Survey
Note: Please see statistics for this survey in Chapter 1.
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APPENDIX C –
RESOLUTION OF ADOPTION
To be inserted after City Council approval.
E1
APPENDIX D –
HAZARD MITIGATION
IMPLEMENTATION HANDBOOK
The following pages contain the City of Rancho Cucamonga’s implementation handbook for this document.
2026 Local Hazard Mitigation Plan City of Rancho Cucamonga
City of Rancho Cucamonga
Local Hazard Mitigation Plan
Implementation Handbook
July 2026
PAGE INTENTIONALLY LEFT BLANK
LHMP Implementation Handbook 1
WHAT IS THIS HANDBOOK?
The Local Hazard Mitigation Plan (LHMP) for the City of Rancho Cucamonga features an evaluation of the City’s hazards as well as a variety of corresponding mitigation actions. These actions are intended to preserve public safety, maintain critical municipal government operations and services when hazard events emerge, and empower community members to take on hazard mitigation at an individual level. This Implementation Handbook (Handbook) is intended for use by City staff and decision makers after the LHMP is adopted. It will:
Give clear instructions as to what to do following adoption of the LHMP. Simplify future updates to the LHMP.
Assist the City in preparing grant funding applications related to hazard mitigation.
Guide annual plan review actions.
HOW DO I USE THIS HANDBOOK?
This Handbook can help City staff and decision makers in several different situations. If and when the events listed below occur, consult the respective sections of this Handbook for advice on how best to proceed:
A disaster proclamation has been issued by the Rancho Cucamonga City Council
A disaster proclamation has been issued by the State of California A disaster declaration has been signed by the Federal Government I want to apply for mitigation grant funding
Rancho Cucamonga is undergoing its budgeting process
Rancho Cucamonga is holding its annual meeting of the Hazard Mitigation Planning Committee
Rancho Cucamonga is updating the following policy and regulatory documents:
The Local Hazard Mitigation Plan
The Safety Element of the General Plan
The Housing Element of the General Plan
The Zoning Code
LHMP Implementation Handbook 2
WHO MAINTAINS THIS HANDBOOK?
The leader of the Hazard Mitigation Planning Committee (HMPC) is the one responsible for maintaining this Handbook. At the time of writing, the current HMPC leader is Riley Davis, from the Rancho Cucamonga Fire Protection District. The HMPC may delegate this responsibility to someone else should they so choose.
WHAT TO DO WHEN A DISASTER HAS BEEN
PROCLAIMED OR DECLARED
Disasters may be proclaimed or declared by the Rancho Cucamonga City Council, the State of California, or the federal government. Responsibilities may differ depending on who proclaims or declares the disaster. If multiple organizations proclaim or declare a disaster, consult all applicable lists.
Rancho Cucamonga City Council Proclamation
If the Rancho Cucamonga City Council (or the Director of Emergency Services, if the City Council is not in session) proclaims a Local Emergency, take the following steps:
Update Attachment 1 with information about the disaster. Include information about cumulative damage, including any damage outside of Rancho Cucamonga.
Discuss opportunities for local assistance with the representatives from the California Office of Emergency Services (Cal OES).
If the disaster damages local infrastructure or City-owned facilities, repair or rebuild the structure to be more resilient, following applicable hazard mitigation actions. A list of actions, organized by hazards, is included as Attachment 4.
Chapter 6 of the Rancho Cucamonga LHMP states that the City should consider updating the LHMP if a disaster causes a loss of life in the community, even if there is no state disaster proclamation or federal disaster declaration that includes part or all of the City. If there is a loss of life in Rancho Cucamonga, consider updating the LHMP. Consult the section on updating the LHMP in this Handbook for details.
LHMP Implementation Handbook 3
State of California Proclamation
If the State of California proclaims a disaster for Rancho Cucamonga, or an area that includes part or all of Rancho Cucamonga, take the following steps:
Update Attachment 1 with information about the disaster. Include information about cumulative damage, including any damage outside of Rancho Cucamonga.
Collaborate with other agencies within the Operational Area to assess the damage from the event.
Collaborate with representatives from Cal OES to assess the damage from the event.
Discuss opportunities for local assistance with representatives from Cal OES. If the disaster damages local infrastructure or City-owned facilities, repair or rebuild the structure to be more resilient, following applicable hazard mitigation actions. A list of actions, organized by hazards, is included as Attachment 4.
If the disaster may escalate into a federal disaster declaration, begin any necessary coordination with representatives from the Federal Emergency Management Agency (FEMA).
Chapter 6 of the Rancho Cucamonga LHMP states that the City should consider updating the LHMP if a disaster leads to a state disaster proclamation or federal disaster declaration that includes part or all of Rancho Cucamonga, even if there is no loss of life. Consider updating the LHMP.
Consult the section on updating the LHMP in this Handbook for details.
Federal Government Declaration
If the federal government declares a disaster for Rancho Cucamonga, or any area that includes part or all of Rancho Cucamonga, take the following steps:
Update Attachment 1 with information about the disaster. Include information about cumulative damage, including any damage outside of Rancho Cucamonga.
Collaborate with other agencies within the Operational Area to assess the damage from the event.
Collaborate with representatives from Cal OES and FEMA to assess the damage from the event.
LHMP Implementation Handbook 4
Determine if Rancho Cucamonga will be eligible for public assistance funds related to the federal disaster declaration. These funds can be used to reimburse the City for response and recovery activities. If the City is eligible, work with FEMA and Cal OES representatives to enact the necessary requirements and receive funding.
If the disaster damages local infrastructure or City-owned facilities, repair or rebuild the structure to be more resilient, following applicable hazard mitigation actions. A list of actions, organized by hazards, is included as Attachment 4.
The Hazard Mitigation Grant Program (HMGP) is a FEMA funding opportunity that helps fund hazard mitigation activities after a disaster event. Rancho Cucamonga may be eligible for funding because of the federal disaster declaration, although not all activities may meet the program’s requirements. If Rancho Cucamonga is eligible, work with FEMA to apply for this funding. Chapter 6 of the Rancho Cucamonga LHMP states that the City should consider updating the LHMP if a disaster leads to a state disaster proclamation or federal disaster declaration that includes part or all of Rancho Cucamonga, even if there is no loss of life. Consider updating the LHMP.
Consult the section on updating the LHMP in this Handbook for details.
HOW TO APPLY FOR MITIGATION GRANT
FUNDING
There are three potential grant funding programs that FEMA administers for hazard mitigation activities. Two of these programs, the Building Resilient Infrastructure and Communities (BRIC) and Flood Mitigation Assistance (FMA) funding sources, are available to communities with an LHMP that complies with FEMA guidelines and has been adopted within the past five years. The third funding program is the Hazard Mitigation Grant Program (HMGP), which is available for communities that are part of a federal disaster declaration. This section discusses the BRIC and FMA programs, and how to apply for them. The HMGP is discussed under the “Federal Government” subsection of the above “What to Do When a Disaster Has Been Proclaimed or Declared” section.
Building Resilient Infrastructure and Communities (BRIC) Building Resilient Infrastructure and Communities (BRIC) will support states, local communities, tribes, and territories as they undertake hazard mitigation projects, reducing the risks they face from disasters and natural hazards. BRIC is a FEMA predisaster hazard mitigation program that replaced the Pre-Disaster Mitigation (PDM) program.
LHMP Implementation Handbook 5
The BRIC program's guiding principles are supporting communities through capabilityand capacity-building, encouraging and enabling innovation, promoting partnerships, enabling large projects, maintaining flexibility, and providing consistency.
Development projects must be identified in a hazard mitigation plan that meets FEMA guidelines and has been adopted within the past five years. When applying to this program, review the list of hazard mitigation actions in Attachment 4 to see which projects may be eligible. Planning efforts for communities that lack a valid hazard mitigation plan may be eligible for funding if the effort would create a valid hazard mitigation plan. All BRIC grant applications are processed through the State. To learn more, consult with Cal OES representatives or visit the FEMA webpage for the program.
Take The Following Steps To Apply For Bric Funding:
Confirm that the program is currently accepting funding applications. Check with representatives from Cal OES or consult the Cal OES webpage on the BRIC program.
Identify the actions from the hazard mitigation strategy (see Attachment 4) that call on the City to pursue funding or list grants as a potential funding source. Confirm that the actions are consistent with the requirements of the BRIC grant.
Coordinate with Cal OES representatives to compile and submit materials for the grant application.
Flood Mitigation Assistance
The FMA grant program is a competitive, national program that awards funding for physical development projects and planning efforts that mitigate against long-term damage from flooding. The funding is only available to communities that participate in the National Flood Insurance Program (NFIP), which Rancho Cucamonga currently does. Communities must also have a valid hazard mitigation plan that meets FEMA guidelines in order to be eligible, and all projects must be consistent with the list of actions in the hazard mitigation strategy. When applying to this program, review the list of hazard mitigation actions in Attachment 4 to see which projects may be eligible. As with the PDM program, applications for the FMA program must be processed through the State. To view more information, consult with Cal OES representatives or visit the FEMA webpage on the program.
Take The Following Steps To Apply For FMA Funding:
Confirm that the program is currently accepting funding applications. Check with representatives from Cal OES or consult the Cal OES webpage on the FMA program.
LHMP Implementation Handbook 6
Identify the actions from the hazard mitigation strategy (see Attachment 4) that call on the City to pursue funding or list grants as a potential funding source. Confirm that the actions are consistent with the requirements of the FMA grant.
Coordinate with Cal OES representatives to compile and submit materials for the grant application
WHAT TO DO…
When Rancho Cucamonga Is Going Through The
Budgeting Process
Rancho Cucamonga’s budget process is an ideal opportunity to secure funding for hazard mitigation actions, and to ensure that hazard mitigation efforts are incorporated into the City’s fiscal priorities. Rancho Cucamonga currently operates on an annual budget cycle that runs from July 1 to June 30. During this process, City staff should take the following steps to incorporate hazard mitigation into Rancho Cucamonga’s annual budget:
Include hazard mitigation activities into Rancho Cucamonga’s list of Capital Improvement Projects (CIP). Review the list of hazard mitigation actions in Attachment 4 and identify the projects that can be included in the CIP or can support efforts within the CIP.
Review the risk and threat assessments in the LHMP (Chapters 3 and 4) to ensure that all items in the CIP are being planned, designed, and constructed so as to minimize the threat from hazard events.
Identify opportunities to identify stand-alone hazard mitigation actions through the annual budget process. Include appropriate items from Attachment 4 in the budget as stand-alone line items, particularly items that the HMPC considered a high priority.
Set aside staff to conduct hazard mitigation activities, including time to participate in HMPC and time to research, prepare, and submit grant applications for funding opportunities (consult the “I Want to Apply for Mitigation Grant Funding” section above).
Ensure that hazard mitigation activities are reflected in each department’s priorities and allocated time to achieve specific goals.