Figure 3.183: Fire Hazard Severity Zones – Inverness
Source: CalFire, 11/27/23
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Figure 3.184: Fire Hazard Severity Zones – Inverness Area Source: CalFire
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Figure 3.185 shows the fire hazard severity zone in and around the Marconi/Marshall Area.
Figure 3.185: Fire Hazard Severity Zones – Marconi/Marshall Area Source: CalFire, 11/27/23
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Figure 3.186 shows the fire hazard severity zones in and around the McDonald/Blakes Landing area.
Figure 3.186: Fire Hazard Severity Zones – McDonald/Blakes Landing Area Source: CalFire, 11/27/23
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Figure 3.187 shows the fire hazard severity zone in and around the Tomales area.
Figure 3.187: Fire Hazard Severity Zones – Tomales
Source: CalFire, 11/27/23
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Figure 3.188 shows the fire hazard severity zone in and around the Dillon Beach area.
Figure 3.188: Fire Hazard Severity Zones – Dillon Beach Source: CalFire, 11/27/23
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Figure 3.189 shows the fire hazard severity zones in and around the Dogtown area.
Figure 3.189: Fire Hazard Severity Zones – Dogtown
Source: CalFire, 11/27/23
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Figure 3.190 shows the fire hazard severity zones in and around the Bolinas area.
Figure 3.190: Fire Hazard Severity Zones – Bolinas
Source: CalFire, 11/27/23
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Figure 3.191 and Figure 3.192 shows the fire hazard severity zone in and around the Stinson Beach area.
Figure 3.191: Fire Hazard Severity Zones – Stinson Beach and Surrounding Area Source: CalFire, 11/27/23
Figure 3.192: Fire Hazard Severity Zones – Stinson Beach Source: CalFire, 11/27/23
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Figure 3.193 shows the fire hazard severity zone in and around the Muir Beach area.
Figure 3.193: Fire Hazard Severity Zones – Muir Beach
Source: CalFire, 11/27/23
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Figure 3.194 shows the fire hazard severity zones in and around Tamalpais Valley and Marin City.
Figure 3.194: Fire Hazard Severity Zones – Tamalpais Valley and Marin City Source: CalFire
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Figure 3.195 shows the fire hazard severity zone in and around the unincorporated area of the Tiburon Peninsula, including Paradise Cay.
Figure 3.195: Fire Hazard Severity Zone – Unincorporated Tiburon Peninsula and Paradise Cay Source: CalFire, 11/27/23
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Figure 3.196 shows the fire hazard severity zone in and around San Quentin.
Figure 3.196: Fire Hazard Severity Zones – San Quentin
Source: CalFire, 11/27/23
Figure 3.197 shows the fire hazard severity zones in and around Lucas Valley and Marinwood.
Figure 3.197: Fire Hazard Severity Zones – Lucas Valley and Marinwood Source: CalFire, 11/27/23
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Figure 3.198 shows the fire hazard severity zones in and around the unincorporated area of Bel Marin Keys and Loma Verde.
Figure 3.198: Fire Hazard Severity Zone – Bel Marin Keys and Loma Verde Source: CalFire
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Figure 3.199 shows the fire hazard severity zone around San Antonio and the Marin County airport.
Figure 3.199: Fire Hazard Severity Zone – San Antonio & Marin County Airport Source: CalFire, 11/27/23
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Figure 3.200 shows the number of state and federal declared wildfire disasters in Marin County in relation to the rest of California.
Figure 3.200: Historic Wildfires in the Marin County OA 1919 - 1995 Source: Marin Community Wildfire Protection Plan
Throughout its history, Marin County has experienced many wildland fires. Figure 3.201 shows a map of large fires that have occurred in Marin County’s unincorporated WUI. 720
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Figure 3.201: Historic Wildfires in the Marin County OA 1973 - 2020 Source: Marin Community Wildfire Protection Plan
9/14/1904 – A wildfire burned 15,000-20,000 acres on Bolinas Ridge. 10/1917 – A wildfire burned 2,000 acres on a ridge near the unincorporated community of Inverness.
7/8/1913 – A wildfire started by a train or a discarded cigarette burned over 1,500 acres on Mount Tamalpais and threatened the City of Mill Valley. 9/17/1923 – September 1923 Wildfire
A wildfire started in the unincorporated community of Ignacio and threatened or destroyed thousands of homes around the unincorporated communities of Ignacio, Woodacre, Lagunitas, and Bolinas Ridge. Thirty-five homes were destroyed in Woodcare, leaving only five left standing. Large areas of timber and grazing land burned. Damage was estimated at $250,000. 9/27/1945 – The Mill Fire
Two brush fires merged together near the unincorporated community of Lagunitas and quickly spread across Bolinas Ridge coming within a quarter mile of the unincorporated community of Stinson Beach. The unincorporated community of Woodacre and the Town of Fairfax were threatened, with over 3,000 residents put on alert for evacuation. Over 18,000 acres burned. 721
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9/1965 – Chileno Valley Fire
Over 8,000 acres burned and several ranches were destroyed in a wildfire. 10/3-10/16/1995 – The Vision Fire
A wildfire started from an illegal campfire burned over 12,000 acres in Point Reyes National Seashore and destroyed 48 structures in the unincorporated community of Inverness.
Figure 3.202: 1995 Vision Fire
Source: Richard Blair
10/13/2008 – Angel Island Fire
A human-caused wildfire burned over 300 acres on Angel Island in Angel Island State Park. No structures were destroyed.
8/27/2019 – Spirit Fire
A wildfire started by arson burned 16 acres above the Sprit Rock Meditation Center near Woodacre.
10/24/2019 – Muir Fire
A 58-acre wildfire burned between the unincorporated communities of Muir Beach and Stinson Beach, closing Highway 1.
8/17/2020 – Woodward Fire
A wildfire burned over 700 acres in a remote area of Point Reyes National Seashore, causing evacuation warnings in the unincorporated community of Olema. 7/14/2021 – Dolcini Fire
A wildfire burned over thirty acres west of Novato.
9/6/2021 – Lucas Valley Wildfire
A wildfire started by a lawn mower burned over 40 acres, prompting evacuations in parts of the unincorporated communities of Lucas Valley and Marinwood.
As part of the CWPP, Ignition data for all authorities having jurisdiction were acquired and analyzed for 2002 through 2011 to evaluate ignition trends within the county. 722
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Impacts
Potential losses from wildfire include human life, structures and other improvements, natural and cultural resources, quality and quantity of water supplies, cropland, timber, and recreational opportunities. Urban wildfires often occur in the WUI, where development has expanded into the rural areas. A wildfire in the WUI can result in major losses of property and structures. Also of significant concern to the planning area are the secondary impacts associated with a large burn area. Wildfires can have devastating effects on watersheds through loss of vegetation and soil erosion, which may impact the County by changing runoff patterns, increasing sedimentation, reducing natural and reservoir water storage capacity, and degrading water quality. These problems can be compounded by climate conditions.
Although the physical damages and casualties arising from wildland-urban interface fires may be severe, it is important to recognize that they also cause significant economic impacts by resulting in a loss of function of buildings and infrastructure. In some cases, the economic impact of this loss of services may be comparable to the economic impact of physical damages or, in some cases, even greater. Economic impacts of loss of transportation and utility services may include traffic delays/detours from road and bridge closures and loss of electric power, potable water, and wastewater services. Threats to healthcare, hazmat releases, ash deposition on properties (including schools), need for proper cleanup, and high costs of hazardous waste cleanup. Both environmental and economic losses occur from contamination of properties which grow produce, both for personal sustenance and commercial distribution.
Wildfires and subsequent smoke can have a negative impact on tourism and visitor use in the County. Wildfires can also cause major damage to power plants and power lines needed to distribute electricity to operate facilities.
Urban structural fires release toxic pollutants into air and water, cause injuries and deaths, mental/behavioral health issues, economic loss consequences of loss/damage to residences or places of business, displacement, cleanup costs to communities and governments, potential increased healthcare utilization due to injuries or chronic disease exacerbations, long term public health impacts including injuries to the response personnel.
There is also a mitigation opportunity. Even though smoke detectors are required in CA, there is no data on how many residential units in CA do not have a smoke detector, whether they have functioning smoke detectors, and whether residents are aware where to place them and how to maintain them. Conducting a rapid community assessment using established methods is one way to gather this information, which could be considered a mitigation action.
Poor air quality can result from wildfires. Sensitive individuals including the very young, elderly and those with respiratory conditions such as asthma and chronic obstructive pulmonary disease (COPD) are at the greatest risk of developing aggravated symptoms such as coughing, watery and itchy eyes, headache, scratchy throat, and difficulty in breathing.
PSPS events can have numerous impacts on residents who rely on electricity for cooling their homes, powering water pumps, keeping critical medical equipment operating, and who have other critical needs. These impacts can become exacerbated during a period of higher temperatures, when community members are unable to cool their homes. PSPS events sometimes occur with little to no warning, and with no clear timeframe on how long the event may last, which presents a challenging situation for community members to be able to prepare for prolonged power outages.
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Extent and Probability
Wildfire threat can be defined as the result of an analysis of potential fire behavior and the likelihood of fire to occur relative to the assets (or communities) at risk. Recent research indicates that higher summer temperatures will likely increase fire severity in California. Future changes in fire frequency and severity are difficult to predict; however, regional climate change associated with elevated greenhouse gas concentrations could alter large weather patterns and produce conditions conducive to extreme fire behavior. A warmer climate will bring drier winters and higher spring temperatures. Combined with drought conditions, this leads to drier soils in early summer, drier vegetation, and an increase in the number of days in the year with flammable fuels, all which further raise the likelihood of fires.
The western U.S. is likely to continue its trend toward warmer and drier conditions, on average, with warmer spring and summer temperatures, reduced snowpack and earlier snowmelts, and longer, drier summer fire seasons. Models and observations, including reconstructions of fire and climate in the past; trends over the last few decades; and predictive models, predict that warming and drying conditions are likely to cause increased fire activity in the future.
Table 3.20: Marin County OA Hazard Risk Assessment – Wildfire Jurisdiction
Probability/
Likelihood
of Future
Events
Geographic
Extent
Magnitude/
Severity
Climate
Change
Influence
Significance Risk
Score
Marin County Highly
Likely Significant Severe High High 16.00
City of
Belvedere
Highly
Likely Limited Extreme Medium High 15.00
Town of
Corte Madera Occasional Significant Extreme High High 15.00 Town of
Fairfax
Highly
Likely Significant Severe Medium Medium 14.00
City of
Larkspur Likely Significant Extreme High High 16.00
City of Mill
Valley Likely Extensive Severe High High 16.00
City of
Novato Likely Limited Weak Medium Medium 10.00
Town of
Ross Likely Extensive Severe Medium High 15.00
Town of
San Anselmo Likely Extensive Extreme High High 17.00
City of
San Rafael Likely Significant Severe High Medium 14.00
City of
Sausalito Occasional Limited Moderate High Medium 11.00 Town of
Tiburon
Highly
Likely Significant Severe High High 16.00
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Bolinas
Public Utility
District
Occasional Extensive Severe High Medium 14.00
Las Gallinas
Valley
Sanitary
District
Likely Negligible Moderate Medium Medium 10.00
North Marin
Water
District
Occasional Extensive Extreme Medium High 15.00
Southern
Marin Fire
District
Occasional Extensive Severe High Medium 15.00
Table 3.20: Marin County OA Hazard Risk Assessment – Wildfire Source: Profiled Jurisdictions and Districts
Vulnerability
While the Cal Fire FHSZ maps are useful in examining potential fire hazard severity at the state level, the underlying data and methods used to develop the FHSZ maps can be improved upon by using local (and more recent) fuel characteristics and improved fire modeling methods. The Cal Fire FHSZ maps also do not take into account local perspectives and priorities regarding communities at risk and areas of concern.
To improve upon the currently available state-level fire hazard assessment information, an independent hazard, asset, risk assessment was performed to help identify and prioritize areas within the county that are potentially at a high threat from wildfire based on more recent fuels data, advanced modeling techniques, and local input. The assessment was performed by modeling potential fire behavior and the probability or likelihood that an area will burn given an ignition. Next, the fire modeling output was combined with areas of concern and assets at risk.
Composite maps were generated indicating relative potential fire hazards throughout the county.
Assets at risk are defined as structures and resources that can be damaged or destroyed by wildland fire. Assets in the Marin County OA include real estate (homes and businesses), all types of healthcare facilities, emergency communication facilities, transportation and utility infrastructure, watersheds, protected wildlands, tourist and recreation areas, and agricultural lands. In addition to providing a framework for protecting community members and providing for firefighter safety, the California Fire Plan identifies the following assets warranting consideration in pre-fire planning: watersheds and water; wildlife; habitat; special status plants and animals; scenic, cultural and historic areas; recreation; rangeland; structures; infrastructure; and air quality.
There are approximately 111,000 living units in the Marin County OA with a median home value of approximately $1 million. As many homes in the county are located in the WUI, if a major wildland fire were to result in the loss of many homes, it could have a short-term negative impact on the Marin County OA’s property tax base.
The Mt. Tamalpais watershed supplies central and southern Marin County with 75% of their fresh water. Given the area’s seasonal rainfall, any major wildfire impacting the heavily forested watershed will result in major silting and subsequent degradation of water quantity and quality in 725
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the watershed. These watershed lands—as well as the lands managed by Marin County Open Space District (MCOSD), state parks, and NPS—are largely contiguous. They harbor several endangered, threatened, and special-status species, including the coho salmon and northern spotted owl.
The area is also part of a major migrating bird flyway and nesting area. The Marin County OA is also a major tourist destination. Major parks within Marin County include California State Parks (Mt. Tamalpais, Samuel P. Taylor, and China Camp), NPS’s Golden Gate National Recreation Area (GGNRA), Muir Woods National Monument, and Point Reyes National Seashore. The Point Reyes National Seashore and Muir Woods National Monument together attract 3.5 million visitors annually. The GGNRA, a majority of which resides within Marin County, attracts an additional 14.9 million visitors per year and contributes an estimated $365.2 million annually to the economy. A major wildfire affecting any of these parks could have negative impacts on the local economy for years after the event.
The Marin County OA’s agricultural land base includes nearly 137,000 acres of privately owned agriculturally zoned land and 32,000 acres of federally-owned land that is leased to agricultural operators. Agricultural operations include livestock and livestock products; aquaculture; field crops; fruit, vegetable, and nursery crops. The gross value of all agricultural production was approximately $101 million in 2014. To help protect people and property from potential catastrophic wildfire, the National Fire Plan identifies communities that are at high risk of damage from wildfire. These high-risk communities identified within the WUI were published in the Federal Register in 2001. In California, CAL FIRE has the responsibility for managing the list. With California's extensive WUI situation, the list of communities extends beyond just those adjacent to Federal lands; there are 1,329 communities currently on the California Communities at Risk List. The Marin County OA has 23 of these at-risk communities. A countywide assessment of the wildland fire threat undertaken by CAL FIRE revealed that nearly 313,000 acres (approximately 82% of the total land area of the county) are ranked as having moderate to very high fire hazard severity zone ratings.
Using the methodology described in the CWPP, a series of models of the hazards, assets, and risks were completed. One model was the average fire season flame length, with lengths above 8 feet possibly exhibiting the more extreme fire behavior and be relatively more hazardous from a fire suppression perspective. Rate of spread is defined as the rate of forward spread of the fire head expressed in feet per minute. The higher the rate of spread, the more difficult a fire is to suppress. A composite map of the flame length, rate of spread, and population density for the average fire season scenario is shown in Figure 3.203; orange and red show areas where more extreme fire behavior is likely given an ignition.
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Figure 3.203: Population Density, Flame Length, and Rate of Spread for the Average Fire Season in the Marin County OA
Source: Marin Community Wildfire Protection Plan, 2020
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Figure 3.204 shows areas of concern for the average fire season in the OA where fuel reduction and hazard mitigation efforts might be focused.
Figure 3.204: Areas of Concern for the Average Fire Season in the Marin County OA Source: Marin Community Wildfire Protection Plan, 2020
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Figure 3.205 shows areas of concern for the average fire season in the OA where fuel reduction and hazard mitigation efforts might be focused.
Figure 3.205: Areas of Concern for the Extreme Fire Season in the Marin County OA Source: Marin Community Wildfire Protection Plan, 2020
Unincorporated rural areas within the OA include the coastal communities of Muir Beach, Stinson Beach, and Bolinas; communities near Tomales Bay including Olema, Point Reyes Station, Inverness, Inverness Park, Marshall, Tomales, and Dillon Beach; and rural areas in the interior valleys including Nicasio, Lagunitas, Forest Knolls, San Geronimo, and Woodacre.
These communities are primarily situated within or adjacent to the WUI, with moderate to dense concentrations of structures. The Marin County OA has approximately 60,000 acres of WUI adjacent to 200,000 acres of watershed. Response times in these communities present significant challenges to keeping fires from directly impacting the communities and sub divisions (especially those within the SRA) as emergency fire access and evacuation egress is limited by narrow, winding roads lined with dense vegetation. Figure 3.206 shows the WUI boundary and population density in the OA.
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Figure 3.206: WUI Boundary and Population Density in the Marin County OA Source: Marin Community Wildfire Protection Plan, 2020
In the Marin County OA, cul-de-sacs generally service new housing developments and most of the smaller canyons, valleys, and hillsides. Some planned unit developments are served by privately- maintained roads, which create access issues (i.e., narrow paved widths and limited on-street parking). According to California Fire Code specifications, roadways that are considered hazardous in terms of fire access and protection are those with • less than 20 feet of unobstructed paved surface and 13.6 vertical feet; • dead-ends longer than 800 feet, and;
• cul-de-sac diameter less than 68 feet.
Driveways that are less than 16 feet wide or that do not have adequate turnaround space are also considered hazardous. A large number of roadways and driveways in many of the Marin County OA’s communities fall into one or more of the above categories.
Several communities in the Marin County OA lie partially or completely in a High and/or Very High FHSZ and could have a higher susceptibility to wildfire. They are highlighted below.
While most of Lagunitas, Forest Knolls San Geronimo and Woodacre lie in a Moderate FHSZ, the surrounding foothills lie in a High FHSZ. There are hundreds of homes in the High FHSZ along with the Woodacre PG&E substation that could have higher susceptible to wildfire. There are hundreds of homes and numerous businesses and critical facilities including the San 730
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Geronimo Community Center, San Geronimo Valley Elementary School, Lagunitas Elementary School, the Woodacre Fire Station and the Heartwood Charter School that lie in the Moderate FHSZ and could be susceptible to wildlife.
The area west and north of Inverness Park primarily lies in a High FHSZ. There are dozens of homes in this area that could have higher susceptibility to wildfire. There is a residential area north of Inverness Park with several dozen homes that lie in a Very High FHSZ and could have an even higher susceptibility to wildfire. Most of the core of Inverness lies in a High FHSZ but the outlying areas north lie in a Very High FHSZ. There are dozens of homes in both these areas that could have higher susceptibility to wildfire. The Inverness Fire Department, Inverness Elementary School and a Marin Emergency Radio Authority (MERA) antenna site lie in a High FHSZ area and could have higher susceptibility to wildfire. Populations from Inverness to Inverness Park are particularly susceptible to wildfire as there is essentially only one main road, Sir Francis Drake Boulevard, that could be used in an evacuation and in only one direction (south).
Most of Dogtown and the northern end of Bolinas lie in a High FHSZ. Several residences, the Bolinas PG&E substation and the Bolinas-Stinson Elementary School lie in this area and could have higher susceptibility to wildfire. Most of Bolinas, where there are dozens of homes, the Bolinas Community Center, the Bolinas Stinson School, the MERA antenna sites at Horseshoe Hill and Bolinas, the Bolinas Community Health Center and the Woodrat Water Treatment Plant lie in a Moderate FHSZ and could be susceptible to wildfire.
While most of Stinson Beach is in a Moderate FHSZ, the surrounding area to the south is in a High FHSZ. Several residences and businesses are in this area and could have higher susceptibility to wildfire. The downtown core of Stinson Beach along with the Stinson Beach Fire Department Stations #1 and #2 lie in a Moderate FHSZ just outside of the High FHSZ and could be susceptible to wildfire. The western end of Stinson Beach along Dipsea Road and Seadrift Road also lies in a Moderate FHSZ and includes dozens of homes that could be susceptible to wildfire.
Most of Muir Beach lies in a High FHSZ. This area includes dozens of homes, several businesses and the Muir Beach Community Center that have higher susceptibility to wildfire.
The Muir Beach Fire Department lies just outside the High FHSZ in a Moderate FHSZ and could be susceptible to wildfire.
Most of Tamalpais Valley and Marin City lie in a Very High FHSZ. There are thousands of homes and buildings in this area of Tamalpais Valley, along with a MERA antenna site, the Marin Horizon School, the Southern Marin Fire Protection District Station #4 and the Tamalpais Valley Elementary School that could have a very high susceptibility to wildfire. Populations in this area are particularly susceptible to wildfire due to the presence of numerous cul de sacs and windy secondary roads that could impede an evacuation. Numerous homes and critical facilities, including the Marin City Health and Wellness Center, the Bayside Martin Luther King Jr. Academy, and the Marin City Fire department lie in the Very High FHSZ of Marin City and could have a very high susceptibility to wildfire. The Very High FHSZ in Tamalpais Valley and Marin City is bordered to the east by a High FHSZ. Hundreds of homes and numerous businesses along with the Commodore Center Heliport lie in the High FHSZ and could have higher susceptibility to wildfire. The Mount Tamalpais School lies in the Moderate FHSZ and could be susceptible to wildfire.
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A small area in the north of Strawberry lies in a High FHSZ with a larger area that lies in a moderate FHSZ. There are several homes in this area that could have higher susceptibility to wildfire.
Most of the unincorporated area of the Tiburon Peninsula lie in a High FHSZ. There are dozens of homes in this area that could have higher susceptibility to wildfire. The eastern boundary of the peninsula lies in a Moderate FHSZ and has several homes that could be susceptible to wildfire.
The far northern and western side of Kentfield lie in a High FHSZ and are bordered to the immediate west by a Very High FHSZ. There are dozens of homes, numerous businesses, the Kentfield Hospital and part of the College of Marin that lie in this area and that have higher susceptibility to wildfire. A smaller part of Kentfield and part of Greenbrae and California City lie in a Moderate FHSZ. There are several homes along with part of the College of Marin that lie in this area and that could be susceptible to wildfire. All of San Quentin, including San Quentin State Prison, lies in a Moderate FHSZ and could be susceptible to wildfire.
While all of Sleepy Hollow lies in a Moderate FHSZ, it is bordered to the east, west, and south by areas of a High FHSZ. Dozens of homes along with the San Domenico School, Sleepy Hollow Villa Medical Facility and the Hidden Valley School that lie in this area could be susceptible to wildfire. Most of Los Ranchitos lies in a High FHSZ with a small part in a moderate FHSZ. There are dozens of homes in this area that could be susceptible to wildfire.
Most of Lucas Valley and Marinwood lie in a High FHSZ. There are hundreds of homes and critical facilities, including several medical facilities, Lucas Valley Elementary School, the Marin County Juvenile Complex, Lucas Valley School, the Marinwood Fire Department, Miller Creek School that lie in this area and have a high susceptibility to wildfire. There is a small section of Marinwood with several homes and part of the Mary E. Silveria Elementary School that lie in a Very High FHSZ and that could have an even higher susceptibility to wildfire. The far eastern end of Lucas Valley, which consists of several homes, lies a Moderate FHSZ and could be susceptible to wildfire.
All of the Saint Vincent area, which includes the Saint Vincent School, lies in a Moderate FHSZ and could be susceptible to wildfire. The Saint Vincent area is surrounded to the west, north and south by a High FHSZ.
Most of San Venetia is not in a FHSZ but the eastern foothills of the San Pedro Mountain Open Space Preserve are in a Moderate FHSZ. There are numerous homes and medical facilities along with the Marin School that lie in this area and that could be susceptible to wildfire. Part of the unincorporated community south of China Camp State Park lies in a Moderate FHSZ.
There are dozens of homes in this area that could be susceptible to wildfire. The southwest side of San Pedro Hill lies in a High FHSZ with a small part lying in a Moderate FHSZ. The McNear Brickyard and other industrial facilities lie in this area and could have an even higher susceptibility to wildfire.
The unincorporated residential area west of Novato lies mostly in a High FHSZ. There are hundreds of homes in this area that could have a high susceptibility to wildfire. The Loma Verde area, which includes dozens of homes and the Loma Verde Elementary School, also lies in a 732
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High FHSZ and could have a high susceptibility to wildfire. This area is bordered to the south by a Very High FHSZ in the City of Novato.
Most of the Black Point-Green Point area lies in a High FHSZ. There are dozens of homes, several businesses, and the Novato Fire Protection District Station #62 that lie in this area and could have a high susceptibility to wildfire. A smaller section south of the Rush Creek Marsh Wildlife Area lies in a Moderate FHSZ. There are numerous homes and businesses in this area that could be susceptible to wildfire.
Numerous unincorporated communities in Marin County include all or part of a Moderate FHSZ and have no High or Very High FHSZ’s including Point Reyes Station, Olema, Nicasio, Tocoloma, Marshall, Tomales, Dillon Beach, Alto, Paradise Cay, and Bel Marin Keys. Hundreds of homes, numerous businesses, and several critical facilities lie in these communities and could be susceptible to wildfire. Critical facilities in these communities susceptible to wildfire include the Nicasio Fire Department, the Nicasio Elementary School, the Tocoloma PG&E substation, the MERA antenna site at Mt. Barnabe, the Olema PG&E substation, the Point Reyes National Seashore Headquarters and Fire Department, the Point Reyes Fire Station, the Marin County Sherrif’s Substation at Point Reyes, the CalTrans Point Reyes Maintenance Station, West Marin Elementary School, Tomales High School, Tomales Elementary School, Tomales Fire Station, MERA antenna site at Tomales and several medical facilities.
The Marin County Airport, the community of San Antonio, and the unincorporated County along the border of Sonoma County all lie in a Moderate FHSZ. There are numerous rural homes, businesses and buildings along with critical facilities including the Hicks Valley Fire Station, Laguna School, Lincoln School, Stafford Junction PG&E substation, MERA antenna site at Coyote Peak that lie in this area and could be susceptible to wildfire.
Marin County populations within the above-listed communities that are most vulnerable to the effects of wildfire include:
• Low-income households
• Households in poverty
• Persons living on single access roads
• Mobile homeowners
• Persons without access to transportation or telecommunications • Outdoor workers
• Healthcare workers, first responders, and protective service occupations • Houseless population
• Children
• Persons with disabilities
• Persons with chronic health problems,
• Senior community members, and
• Persons living alone.
See the Marin County CWPP for additional information on the susceptibility of the Marin County OA to wildfire.
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Climate Change and Future Development Considerations
Climate change can lead to an increase in wildfire events. Climate change has been a key factor in increasing the risk and extent of wildfires in the western United States. Changes in climate create warmer, drier conditions. Increased drought, and a longer fire season are boosting these increases in wildfire risk.
Figure 3.207: Trends in the Annual Number of Large Wildfires in the United States Source: Fourth Climate Change Assessment
As summer conditions in Northern California become hotter and drier due to climate change, the occurrence and severity of wildfires will only increase. The Marin County OA is particularly susceptible to these future impacts of climate change on wildfire, as the OA’s climate has generally been wet enough historically to avoid major wildfires. Extreme heat events and high wind events could cause electrical systems to become overloaded and fail, sparking wildfires.
An increase in wildfires as a result of climate change could lead to more significantly burned areas that could contribute to debris flows after a significant storm event. Future development in the WUI throughout the Marin County OA will expose more people and property to the impacts of a potentially significant wildfire. The growing number of people in the Marin County OA WUI can increase risk to life, property and public health as a result of a wildfire.
3.4 ADDITIONAL HAZARDS PROFILED
Additional non-natural hazards were identified as having some potential to impact the planning area. The sections below provide short profiles of each of these hazards, including qualitative discussion of their potential to impact Marin County. No formal risk assessment of these hazards was performed, and no mitigation initiatives have been developed to address them. 734
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3.4.1 AIR POLLUTION
Air pollution is contamination of the indoor or outdoor environment by any chemical, physical or biological agent that modifies the natural characteristics of the atmosphere.
Household combustion devices, motor vehicles, industrial facilities and forest fires are common sources of air pollution. Pollutants of major public health concern and their effects on health and the environment include:
Ozone (O3)
• Respiratory symptoms
• Worsening of lung disease leading to premature death
• Damage to lung tissue
• Crop, forest and ecosystem damage
• Damage to a variety of materials, including rubber, plastics, fabrics, paint and metals PM2.5 (particulate matter less than 2.5 microns in aerodynamic diameter) • Premature death
• Hospitalization for worsening of cardiovascular disease • Hospitalization for respiratory disease
• Asthma-related emergency room visits
• Increased symptoms, increased inhaler usage
PM10 (particulate matter less than 10 microns in aerodynamic diameter) • Premature death & hospitalization, primarily for worsening of respiratory disease • Reduced visibility and material soiling
Nitrogen Oxides (NOX)
• Lung irritation
• Enhanced allergic responses
Carbon Monoxide (CO)
• Chest pain in patients with heart disease
• Headache
• Light-headedness
• Reduced mental alertness
Sulfur Oxides (SOX)
• Worsening of asthma: increased symptoms, increased medication usage, and emergency room visits
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Lead
• Impaired mental functioning in children
• Learning disabilities in children
• Brain and kidney damage
Hydrogen Sulfide (H2S)
• Nuisance odor (rotten egg smell)
• At high concentrations: headache & breathing difficulties Sulfate
• Same as PM2.5, particularly worsening of asthma and other lung diseases • Reduces visibility
Vinyl Chloride
• Central nervous system effects, such as dizziness, drowsiness & headaches • Long-term exposure: liver damage & liver cancer
Visibility Reducing Particles
• Reduced airport safety, scenic enjoyment, road safety, and discourages tourism Toxic Air Contaminants (about 200 chemicals have been listed as toxic air contaminants) • Cancer
• Reproductive and developmental effects
• Neurological effects
Outdoor and indoor air pollution cause respiratory and other diseases and are important sources of morbidity and mortality.
The World Health Organization (WHO) shows that almost all of the global population (99%) breathe air that exceeds WHO guideline limits and contains high levels of pollutants, with lowand middle-income countries suffering from the highest exposures.
Air quality is closely linked to the earth’s climate and ecosystems globally. Many of the drivers of air pollution (i.e. combustion of fossil fuels) are also sources of greenhouse gas emissions.
Climate change–fueled wildfires and extreme heat are adding to the challenges of protecting public health. Policies to reduce air pollution, therefore, offer a win-win strategy for both climate and health, lowering the burden of disease attributable to air pollution, as well as contributing to the near- and long-term mitigation of climate change.
Mold and allergens from trees, weeds, and grass are also carried in the air, are exacerbated by climate change, and can be hazardous to health. Though they aren’t regulated and are less directly connected to human actions, they can be considered a form of air pollution. Pollen allergies are worsening because of climate change.
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135 million people or four out of ten U.S. residents live in counties with unhealthy levels of air pollution. Air monitoring shows that over 90 percent of Californians breathe unhealthy levels of one or more air pollutants during some part of the year. In the U.S., the Clean Air Act has been a crucial tool for reducing air pollution since its passage in 1970. The most effective way to control air pollution is to speed up the transition to cleaner fuels and industrial processes. By switching over to renewable energy sources such as wind and solar power, maximizing fuel efficiency in vehicles, and replacing more and more gasoline-powered cars and trucks with electric versions, air pollution can be limited at its source while also curbing the global warming that worsens so many of its worst health impacts.
Air Quality Index (AQI) & Health
Millions of people live in areas where air pollution can cause serious health problems. Local air quality can affect our daily lives. Like the weather, it can change from day to day. The Environmental Protection Agency (EPA) developed the Air Quality Index, or AQI, to make information available about the health effects of the five most common air pollutants, and how to avoid those effects.
The AQI is an index for reporting daily air quality. It tells you how clean or polluted your air is, and what associated health effects might be a concern for you. The AQI focuses on health affects you may experience within a few hours or days after breathing polluted air. EPA calculates the AQI for five major air pollutants regulated by the Clean Air Act: ground-level ozone, particle pollution (also known as particulate matter), carbon monoxide, sulfur dioxide, and nitrogen dioxide. For each of these pollutants, EPA has established national air quality standards to protect public health. Ground-level ozone and airborne particles are the two pollutants that pose the greatest threat to human health in this country. https://www.airnow.gov/
https://airnow.gov/index.cfm?action=aqi_brochure.index
The purpose of the AQI is to help you understand what local air quality means to your health. To make it easier to understand, the AQI is divided into six categories: Note: Values above 500 are considered Beyond the AQI. Follow recommendations for the Hazardous category. Additional information on reducing exposure to extremely high levels of particle pollution is available here.
Each category corresponds to a different level of health concern. The six levels of health concern and what they mean are depicted in the figure below. 737
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Figure 3.208: Air Quality Index Concern Levels
Source: AirNow.gov
In the Bay Area, a certain amount of air pollution comes from industrial sources, such as refineries and power plants. But a greater percentage of harmful air emissions comes from cars and trucks, construction equipment, and other motor vehicles. In the wintertime, the largest single source of air pollution is residential wood burning. Ozone and fine particle pollution, or PM2.5, are the major regional air pollutants of concern in the San Francisco Bay Area. Ozone is primarily a problem in the summer, and fine particle pollution in the winter. Along the Marin County coast and in southern Marin County, clean air from the Pacific Ocean helps to keep air pollution at a minimum. Elsewhere in the Marin County OA, ozone only rarely becomes a concern, but the hilly terrain and colder winter temperatures can trap PM2.5 near the surface, resulting in air quality that exceeds health standards.
The Bay Area Air Quality Management District (BAAQMD) is the official air pollution control agency for the San Francisco Bay Area, which includes Marin County. They have issued numerous poor air quality advisories for Marin County over the years as a result of wildfires.
3.4.2 CRITICAL INFRASTRUCTURE/ UTILITY DISRUPTION
Critical Infrastructure and utility disruption is defined as the disruption of one or more of the physical structures, facilities, networks and other assets which provide services that are essential to the social and economic functioning of a community or society. Examples of infrastructure disruptions include building collapses, water main breaks, gas pipe ruptures, steam pipe explosions, communication system failures and related types of events. These disruptions can be caused by natural disasters such as a landslide or earthquake, by man-made disasters such as a train or major vehicle crash, or by acts of sabotage including terrorism. 738
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Climate change is expected to heavily affect infrastructure through heatwaves, floods and droughts. Figure 3.208 shows critical infrastructure across the Marin County OA.
Figure 3.209: Marin County OA Critical Infrastructure
Source: Marin County
The availability of critical infrastructure and utilities are crucial for timely recovery after a disaster induced by natural hazards. Maintaining or quickly restoring road access, drinking water supply or healthcare can save lives. Very often disasters are exacerbated by poor infrastructure.
Preparing critical infrastructures, as well as the population, for long-term outages due to natural hazards is crucial. When critical infrastructure and utilities have a disruption, it can disproportionately affect socially vulnerable populations. For individuals stuck at home and who rely on timely medication or electrical devices, a situation can quickly become critical if road access and power supplies are damaged. The increasing complexity, interdependency and scale of infrastructure networks can make them more difficult to protect. While technological developments have improved the quality of essential services, this progress itself creates new vulnerabilities.
Beyond power outages caused by storms, wildfires and PSPS events, the Marin County OA has had no significant critical infrastructure or utility disruptions. Other critical infrastructure and utility disruptions across California and the United States have occurred, however, and could similarly occur in the Marin County OA including the 2011 Southwest power failure, the 2010 San Bruno PG&E gas line explosion, and the 2007 I-35 bridge collapse in Minneapolis, Minnesota.
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3.4.3 CYBER THREATS
A cyber threat is any circumstance or event with the potential to adversely impact organizational operations (including mission, functions, image, or reputation), organizational assets, or individuals through an information system via unauthorized access, destruction, disclosure, modification of information, and/or denial of service. A cyber threat is also the potential for a threat-source to successfully exploit a particular information system vulnerability. Cyber threats include:
Malware
Malware — or malicious software — is any program or code that is created with the intent to do harm to a computer, network or server. Malware is the most common type of cyberattack, mostly because this term encompasses many subsets such as ransomware, trojans, spyware, viruses, worms, keyloggers, bots, cryptojacking, and any other type of malware attack that leverages software in a malicious way. Types of malware include:
Ransomware: In a ransomware attack, an adversary encrypts a victim’s data and offers to provide a decryption key in exchange for a payment. Ransomware attacks are usually launched through malicious links delivered via phishing emails, but unpatched vulnerabilities and policy misconfigurations are used as well.
Fileless Malware: Fileless malware is a type of malicious activity that uses native, legitimate tools built into a system to execute a cyber attack. Unlike traditional malware, fileless malware does not require an attacker to install any code on a target’s system, making it hard to detect.
Spyware: Spyware is a type of unwanted, malicious software that infects a computer or other device and collects information about a user’s web activity without their knowledge or consent.
Adware: Adware is a type of spyware that watches a user’s online activity in order to determine which ads to show them. While adware is not inherently malicious, it has an impact on the performance of a user’s device and degrades the user experience.
Trojan: A trojan is malware that appears to be legitimate software disguised as native operating system programs or harmless files like free downloads. Trojans are installed through social engineering techniques such as phishing or bait websites.
Worm: A worm is a self-contained program that replicates itself and spreads its copies to other computers. A worm may infect its target through a software vulnerability or it may be delivered via phishing or smishing. Embedded worms can modify and delete files, inject more malicious software, or replicate in place until the targeted system runs out of resources.
Rootkit: Rootkit malware is a collection of software designed to give malicious actors control of a computer network or application. Once activated, the malicious program sets up a backdoor exploit and may deliver additional malware.
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Mobile Malware: Mobile malware is any type of malware designed to target mobile devices.
Mobile malware is delivered through malicious downloads, operating system vulnerabilities, phishing, smishing, and the use of unsecured WiFi.
Exploit: An exploit is a piece of software or data that opportunistically uses a defect in an operating system or an app to provide access to unauthorized actors. The exploit may be used to install more malware or steal data.
Scareware: Scareware tricks users into believing their computer is infected with a virus.
Typically, a user will see scareware as a pop-up warning them that their system is infected.
This scare tactic aims to persuade people into installing fake antivirus software to remove the “virus.” Once this fake antivirus software is downloaded, then malware may infect your computer.
Keylogger: Keyloggers are tools that record what a person types on a device. While there are legitimate and legal uses for keyloggers, many uses are malicious. In a keylogger attack, the keylogger software records every keystroke on the victim’s device and sends it to the attacker.
Botnet: Botnet is a network of computers infected with malware that are controlled by a bot herder. The bot herder is the person who operates the botnet infrastructure and uses the compromised computers to launch attacks designed to crash a target’s network, inject malware, harvest credentials or execute CPU-intensive tasks.
Denial and Distributed Denial of Service Attacks
A Denial-of-Service (DoS) attack is a malicious, targeted attack that floods a network with false requests in order to disrupt business operations.
In a DoS attack, users are unable to perform routine and necessary tasks, such as accessing email, websites, online accounts or other resources that are operated by a compromised computer or network. While most DoS attacks do not result in lost data and are typically resolved without paying a ransom, they cost the organization time, money and other resources in order to restore critical business operations.
The difference between DoS and Distributed Denial of Service (DDoS) attacks has to do with the origin of the attack. DoS attacks originate from just one system while DDoS attacks are launched from multiple systems. DDoS attacks are faster and harder to block than DOS attacks because multiple systems must be identified and neutralized to halt the attack.
Phishing
Phishing is a type of cyberattack that uses email, SMS, phone, social media, and social engineering techniques to entice a victim to share sensitive information — such as passwords or account numbers — or to download a malicious file that will install viruses on their computer or phone. Types of phishing include:
Spear Phishing: Spear-phishing is a type of phishing attack that targets specific individuals or organizations typically through malicious emails. The goal of spear phishing is to steal sensitive information such as login credentials or infect the targets’ device with malware. 741
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Whaling: A whaling attack is a type of social engineering attack specifically targeting senior or executive employees with the purpose of stealing money or information, or gaining access to the person’s computer in order to execute further cyberattacks.
SMiShing: Smishing is the act of sending fraudulent text messages designed to trick individuals into sharing sensitive data such as passwords, usernames and credit card numbers. A smishing attack may involve cybercriminals pretending to be your bank or a shipping service you use.
Vishing: Vishing, a voice phishing attack, is the fraudulent use of phone calls and voice messages pretending to be from a reputable organization to convince individuals to reveal private information such as bank details and passwords.
Spoofing
Spoofing is a technique through which a cybercriminal disguises themselves as a known or trusted source. In so doing, the adversary is able to engage with the target and access their systems or devices with the ultimate goal of stealing information, extorting money or installing malware or other harmful software on the device. Types of spoofing include:
Domain Spoofing: Domain spoofing is a form of phishing where an attacker impersonates a known business or person with fake website or email domain to fool people into the trusting them. Typically, the domain appears to be legitimate at first glance, but a closer look will reveal subtle differences.
Email Spoofing: Email spoofing is a type of cyberattack that targets organizations by using emails with forged sender addresses. Because the recipient trusts the alleged sender, they are more likely to open the email and interact with its contents, such as a malicious link or attachment.
ARP Spoofing: Address Resolution Protocol (ARP) spoofing or ARP poisoning is a form of spoofing attack that hackers use to intercept data. A hacker commits an ARP spoofing attack by tricking one device into sending messages to the hacker instead of the intended recipient. This way, the hacker gains access to your device’s communications, including sensitive data.
Code Injection Attacks
Code injection attacks consist of an attacker injecting malicious code into a vulnerable computer or network to change its course of action. Types of code injection attacks include:
SQL Injection: A Structured Query Language (SQL) Injection attack leverages system vulnerabilities to inject malicious SQL statements into a data-driven application, which then allows the hacker to extract information from a database. Hackers use SQL Injection techniques to alter, steal or erase application's database data.
Cross-Site Scripting (XSS): Cross Site Scripting (XSS) is a code injection attack in which an adversary inserts malicious code within a legitimate website. The code then launches as an infected script in the user’s web browser, enabling the attacker to steal sensitive information or impersonate the user. Web forums, message boards, blogs and other websites that allow users to post their own content are the most susceptible to XSS attacks. 742
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Malvertising: Malvertising attacks leverage many other techniques to carry out the attack.
Typically, the attacker begins by breaching a third-party server, which allows the cybercriminal to inject malicious code within a display ad or some element thereof, such as banner ad copy, creative imagery or video content. Once clicked by a website visitor, the corrupted code within the ad will install malware or adware on the user’s computer.
Identity-Based Attacks
Identity-based attacks are attacks on the behavior of an individual and are extremely hard to detect. When a valid user’s credentials have been compromised and an adversary is masquerading as that user, it is often very difficult to differentiate between the user’s typical behavior and that of the hacker using traditional security measures and tools. Types of identitybased attacks include:
Kerberoasting: Kerberoasting is a post-exploitation attack technique that attempts to crack the password of a service account within the active directory where an adversary masquerading as an account user with a service principal name requests a ticket, which contains an encrypted password, or Kerberos.
Man-in-the-Middle (MITM) Attack: A man-in-the-middle attack is a type of cyberattack in which an attacker eavesdrops on a conversation between two targets with the goal of collecting personal data, passwords or banking details, and/or to convince the victim to take an action such as changing login credentials, completing a transaction or initiating a transfer of funds.
Pass-the-Hash Attack: Pass the hash (PtH) is a type of attack in which an adversary steals a “hashed” user credential and uses it to create a new user session on the same network. It does not require the attacker to know or crack the password to gain access to the system.
Rather, it uses a stored version of the password to initiate a new session.
Silver Ticket Attack: A silver ticket is a forged authentication ticket often created when an attacker steals an account password. A forged service ticket is encrypted and enables access to resources for the specific service targeted by the silver ticket attack.
Credential Stuffing: Credential stuffing attacks work on the premise that people often use the same user ID and password across multiple accounts. Therefore, possessing the credentials for one account may be able to grant access to other, unrelated account.
Password Spraying: The basics of a password spraying attack involve a threat actor using a single common password against multiple accounts on the same application. This avoids the account lockouts that typically occur when an attacker uses a brute force attack on a single account by trying many passwords.
Brute Force Attacks: A brute force attack uses a trial-and-error approach to systematically guess login info, credentials, and encryption keys. The attacker submits combinations of usernames and passwords until they finally guess correctly.
Insider Threats
Insider threats are internal actors such as current or former employees that pose danger to an organization because they have direct access to the company network, sensitive data, and 743
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intellectual property (IP), as well as knowledge of business processes, company policies or other information that would help carry out such an attack.
Internal actors that pose a threat to an organization tend to be malicious in nature. Some motivators include financial gains in exchange for selling confidential information on the dark web, and/or emotional coercion using social engineering tactics. On the other hand, some insider threat actors are not malicious in nature but instead are negligent in nature. To combat this, organizations should implement a comprehensive cybersecurity training program that teaches stakeholders to be aware of any potential attacks, including those potentially performed by an insider.
Supply Chain Attacks
A supply chain attack is a type of cyberattack that targets a trusted third-party vendor who offers services or software vital to the supply chain. Software supply chain attacks inject malicious code into an application in order to infect all users of an app, while hardware supply chain attacks compromise physical components for the same purpose. Software supply chains are particularly vulnerable because modern software is not written from scratch: rather, it involves many off-the-shelf components, such as third-party APIs, open-source code and proprietary code from software vendors.
DNS tunneling
DNS Tunneling is a type of cyberattack that leverages domain name system (DNS) queries and responses to bypass traditional security measures and transmit data and code within the network. Once infected, the hacker can freely engage in command-and-control activities. This tunnel gives the hacker a route to unleash malware and/or to extract data, IP or other sensitive information by encoding it bit by bit in a series of DNS responses. DNS tunneling attacks have increased in recent years, in part because they are relatively simple to deploy. Tunneling toolkits and guides are even readily accessible online through mainstream sites like YouTube.
IoT-Based Attacks
An IoT attack is any cyberattack that targets an Internet of Things (IoT) device or network. Once compromised, the hacker can assume control of the device, steal data, or join a group of infected devices to create a botnet to launch DoS or DDoS attacks. Given that the number of connected devices is expected to grow rapidly over the next several years, cybersecurity experts expect IoT infections to grow as well. Further, the deployment of 5G networks, which will further fuel the use of connected devices, may also lead to an uptick in attacks.
The Marin County OA has had several cybersecurity issues. More than $300,000 was stolen by fraudulent electronic transfers at the Marin County Civic Center, unwittingly approved by county financial gatekeepers in 2018. Marin County’s computer network has been hacked into and breached at least five times between July 2017 and August 2018. In addition, more than half of Marin’s cities — Corte Madera, Fairfax, Larkspur, Novato, Sausalito and Tiburon — have had their cybersecurity compromised including:
Town of Fairfax: In July 2016, Fairfax was victimized by a ransomware attack. An employee received an email with a malware program attached; and when the employee clicked on the attachment, the town’s servers were infected and became unusable. No ransom was paid, but the town was forced to use a previous backup in order to rebuild its systems. The Town lost data 744
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for the day of the attack, since it had not yet been backed up. The Town suffered a similar breach in October 2014.
City of Novato: In 2017, Novato fell victim to a phishing attack. A city employee received an email purporting to be from a senior city official, requesting a wire transfer of funds. The employee initiated the wire transfer to the account specified by the hacker. The breach was reported to local law enforcement and the FBI. After the attack, the City strengthened its email security and implemented mandatory employee training to reduce its vulnerability to emailbased attacks.
City of Sausalito: In January 2018, Sausalito was the victim of a phishing attack in which a fake email, purporting to be from the city manager, was sent to a city employee. This employee complied with the fake email’s request for copies of the W-2 tax forms of all of the city’s employees and councilmembers. As a result, all these individuals were exposed to the risk of identity theft. The Sausalito breach was reported to the FBI. For two years after the attack, the city provided free credit monitoring services to all employees, at a cost of approximately $27,000. Nevertheless, three employees had fraudulent state tax returns filed in their names, although the attempts were unsuccessful because taxing authorities had been alerted.
Town of Tiburon: In 2019, Tiburon suffered a ransomware attack, also initiated by a fake email attachment opened by an employee. No ransom was paid, but the Town’s systems were largely disabled for more than three days. Most of its data was recovered using a backup, but the town discovered that one of its applications was not being backed up properly, so the town needed to rebuild much of that data by hand from paper records.
Town of Corte Madera: In 2019, Corte Madera suffered a direct attack. During a brief moment when a vendor intentionally disabled the town’s firewall for system updates, hackers were able to access its network and disable it using ransomware. No ransom was paid, but the system had to be restored from a backup.
City of Larkspur: In August 2019, Larkspur’s network was compromised in a direct attack. Four of its computers were reportedly accessed from one of the public computers in the Larkspur library. It is unknown what data may have been accessed.
Having a comprehensive cybersecurity strategy is vital. Organizations should secure their critical areas of risk, know their threats, be ready to respond quickly to a threat, monitor the criminal underground through hidden messaging platforms and dark web forums, utilize technology to stop sophisticated threats, and build a comprehensive cybersecurity training program.
3.4.4 OIL SPILLS
Oil spills can happen anywhere oil is drilled, transported, or used. They can happen in many different ways including when pipelines break, oil tanker ships sink, or drilling operations go wrong. Consequences to ecosystems and economies can be felt for decades following a large oil spill. Thousands of oil spills occur in U.S. waters each year. Most of these spills are small but can still cause damage, especially if they happen in sensitive environments, like beaches and wetlands. Large oil spills can be significant disasters. 745
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Where oil is spilled, what kinds of plants, animals, and habitats are found there, and the amount and type of oil, among other things, can influence how much harm an oil spill causes. Generally, oil spills harm ocean life in two ways:
Fouling or oiling: Fouling or oiling occurs when oil physically harms a plant or animal. Oil can coat a bird’s wings and leave it unable to fly or strip away the insulating properties of a sea otter’s fur, putting it at risk of hypothermia. The degree of oiling often impacts the animal’s chances of survival.
Oil toxicity: Oil consists of many different toxic compounds. These toxic compounds can cause severe health problems like heart damage, stunted growth, immune system effects, and even death. Our understanding of oil toxicity has expanded by studying the effects of the 2010 Deepwater Horizon oil spill.
Wildlife recovery, cleaning, and rehabilitation is often an important part of oil spill response.
However, wildlife is difficult to find and catch, oil spills can happen over wide areas, and some animals (like whales) are too big to recover. Unfortunately, it’s unrealistic to rescue all wildlife impacted during oil spills.
The U.S Coast Guard is primarily responsible for cleaning up oil spills, while NOAA provides scientific support to make decisions that protect people and the environment. There are different equipment and tactics that trained experts can use to contain or remove oil from the environment when a spill occurs:
Booms are floating physical barriers to oil, which help keep it contained and away from sensitive areas, like beaches, mangroves, and wetlands.
Skimmers are used off of boats and can “skim” oil from the sea surface. In situ burning, or setting fire to an oil slick, can burn the oil away at sea, and chemical dispersants can break up oil slicks from the surface.
Cleanup activities can never remove 100% of the oil spilled, and scientists have to be careful that their actions don’t cause additional harm.
Figure 3.209 shows the largest oil spills affecting United States waters from 1969-2017. 746
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Figure 3.210: Largest Oil Spills Affecting U.S. Waters 1969-2017 Source: NOAA
The Marin County OA has been impacted by oil spills. In 2007, an oil tanker colided with one of the San-Francisco Oakland Bay Bridge towers. It spilled 53,569 gallons of bunker fuel into San Francisco Bay. The tidal mechanics of San Francisco Bay caused the spill to spread rapidly, affecting a large area of the California North Coast, including the Golden Gate National Recreation Area, Ocean Beach and the Marin Headlands. More than 50 public beaches were closed, including Crissy Field, Fort Point, Baker Beach, China Beach and Kirby Cove. Beaches as far south as Pacifica, California were closed due to the spill. According to Federal and State natural resource trustee agencies, the spill is estimated to have killed 6,849 birds. Several fisheries in the Bay Area may have been affected by the spill, and the crab and sport fishing seasons were postponed by several weeks. As of the end of November 2007, State biologists had tested more than 1100 samples of fish, mussels and Dungeness crab in San Francisco Bay and coastal waters outside the Golden Gate. The tests found unsafe levels of contaminants in mussels from Rodeo Beach and the Berkeley pier. An estimated 1,079,900 recreational use days were also lost as a result of the spill. This includes general shoreline use as well as recreational fishing and boating. Total monetary damages were estimated at more than $70 million for oil spill cleanup.
In 1971, a spill occurred in the San Francisco Bay when two tankers collided and spilled 800,000 gallons of oil, threatening significant sensitive habitat inside and outside the Bay, including the Bolinas Lagoon.
On March 6, 2021, a steel shackle connecting a tugboat to the American Challenger, a 90-foot decommissioned vessel, failed in Bodega Bay, causing the American Challenger to drift into shore. A Coast Guard crew was monitoring it at the time and reported the commercial vessel grounded north of Dillon Beach, off Pt Reyes.
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Officials representing the Marin County Sheriff’s Office of Emergency Services, the U.S. Coast Guard, the EPA, California Department of Fish and Wildlife, the National Oceanic and Atmospheric Administration, and state Office of Spill Prevention and Response, responded to the scene and attempted to contain the oil and other hazardous materials leaking from the vessel, ensuring debris and toxic substances did not stray into the surrounding Greater Farallones National Marine Sanctuary. About $2.3 million was spent on the initial response and costs related to the stranding, including oil booms, environmental assessments, shoreline surveys and Coast Guard costs, according to the Office of Spill Prevention and Response. The Environmental Protection Agency, Region 9, paid an estimated $1 million for the dismantling and disposal of the vessel.
Additional oil spills have impacted other areas of California:
In 1910, The Lakeview Gusher created the largest accidental oil spill in history, lasting 18 months and releasing an estimated 9 million barrels of crude oil. It occurred due to an eruption of hydrocarbons from a pressurized oil well in the Midway-Sunset Oil Field in Kern County, California.
In 1969, a blowout on an offshore platform off the coast of Santa Barbara, California, spilled over four million gallons of oil.
In 2021, a major oil spill occurred in Orange County, California, originating from an underwater pipe connected to the Elly platform about 4.5 miles offshore near Long Beach. The U.S. Coast Guard estimated that spill covered 8,320 acres of the ocean's surface, spilling approximately 24,696 gallons of oil.
Two of the most significant marine oil spills in American history, each of which was the largest oil spill into American waterways at the time, include:
In 1989, the Exxon Valdez oil tanker ran aground in the Prince William Sound in Alaska, spilling over 11 million gallons of oil.
On April 20, 2010, an explosion occurred on the Deepwater Horizon drilling platform in the Gulf of Mexico, killing 11 people. Before it was capped three months later, approximately 134 million gallons of oil had spilled into the ocean making it the largest marine oil spill in U.S. history. That is equivalent to the volume of over 200 Olympic-sized swimming pools.
While there is currently no oil drilling offshore of Northern California, including Marin County, the potential exists for new drilling to occur in the area in the future. Onshore drilling also does not occur in the Marin County OA. Currently, an oil spill affecting Marin County would most likely emanate from a ship accident as there are no oil pipelines in the Marin County OA.
Environmental, economic, and recreational impacts to the Marin County shoreline could be significant depending on the location of the spill and the tides.
3.4.5 PANDEMIC
A pandemic is a disease outbreak that spreads across countries or continents. It affects more people and takes more lives than an epidemic.
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An epidemic is when an infectious disease spreads quickly to more people than experts would expect. It usually affects a larger area than an outbreak.
An outbreak is when an illness happens in unexpected high numbers. It may stay in one area or extend more widely. An outbreak can last days or years. Sometimes, experts consider a single case of a contagious disease to be an outbreak. This may be true if it’s an unknown disease, if it’s new to a community, or if it’s been absent from a population for a long time.
The number of lives lost in a pandemic depends on:
• How many people are infected.
• How severe of an illness the virus causes (its virulence). • How vulnerable certain groups of people are.
• Prevention efforts and how effective they are.
The California Department of Public Health has identified several diseases that could contribute to an outbreak, epidemic or pandemic in California:
Animal Transmitted
These are diseases that are transmitted to humans by domestic or non-domestic animals.
Examples include:
• Brucellosis (undulant fever)
• Campylobacteriosis
• Cat scratch disease
• Cryptosporidiosis
• Escherichia coli (E. coli)
• Giardiasis
• Middle Eastern Respiratory Syndrome (MERS)
• Plague
• Psittacosis (ornithosis, parrot fever)
• Q Fever
• Rabies
• Ringworm
• Salmonellosis
• Toxoplasmosis
• Tularemia
Bloodborne
Viruses, bacteria and parasites that can be carried in blood and cause disease are known as bloodborne pathogens. Transmission of these diseases may be from direct blood contact, needle sticks, intravenous drug use, sexual behavior, insects or other vectors. Examples include:
• Tularemia
• Ebola
• Hepatitis C
• Malaria
Community-Acquired Infections
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Community-acquired infections are infections that are contracted outside of a hospital (or are diagnosed within 48 hours of admission) without any previous health care encounter. Examples include:
• Adenovirus
• Bed Bugs
• Body Lice
• Campylobacteriosis
• Conjunctivitis (pink eye)
• Common cold viruses
• Enterovirus, non-polio
• Hand, foot, and mouth disease
• Head Lice (‘ukus)
• Impetigo
• Influenza (flu)
• Invasive Group A Streptococcus (necrotizing fasciitis) • Legionnaires’ Disease/Pontiac Fever
Foodborne
Foodborne diseases can be spread when food becomes contaminated with fecal matter containing bacteria, viruses, or parasites. This contamination can happen at a farm, manufacturing plant, restaurant, or home. Foodborne diseases usually result in gastrointestinal illness, which can include symptoms such as diarrhea, vomiting, nausea, stomachache, and fever. People who are ill with a foodborne disease can give the infection to others, so proper hygiene and hand washing practices are essential to limit the spread of disease. People experiencing gastrointestinal symptoms should not prepare or handle food for others. Examples include:
• Amebiasis
• Angiostrongyliasis (rat lungworm)
• Anisakiasis
• Botulism
• Brucellosis (undulant fever)
• Campylobacteriosis
• Cholera
• Ciguatera fish poisoning
• Cryptosporidiosis
• Cyclosporiasis
• Escherichia coli (E. coli)
• Giardiasis
• Listeriosis
• Norovirus
• Salmonellosis
• Scombroid
• Shigellosis
• Tularemia
• Typhoid Fever
• Vibriosis
• Yersinia enterocolitica
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Influenza
Influenza is an infectious viral disease of birds and mammals commonly transmitted through airborne aerosols such as coughing or sneezing. Symptoms are chills, headache, fever, nausea, muscle pain and occasionally pneumonia. Flu pandemics in the late 19th and 20th centuries include:
• Russian flu
• 1918 Spanish flu
• Asian flu
• Hong Kong flu
• A/H1N1 or the swine flu.
Avian flu strains H5N1 and H7N9 caused human deaths but did not escalate to pandemic proportions.
Mosquito-Transmitted
Mosquitoes found in California are capable of spreading many diseases to humans and animals. Examples include:
• Malaria
• Yellow fever
• Dengue
• Chikungunya
• Zika
• Canine heartworm
• West Nile virus
• Other encephalitis viruses
Historically, California has experienced local transmission of malaria, western equine encephalomyelitis, St. Louis encephalitis, California encephalitis viruses, canine heartworm, and West Nile virus. Canine heartworm and West Nile virus continue to have frequent local transmission in California, with West Nile virus human cases numbering in the hundreds every year. With increased global travel, the potential exists for the introduction or reintroduction of many mosquito-borne diseases into California.
Waterborne Diseases
Diseases caused by micro-organisms transmitted in water can be spread while bathing, washing, drinking water, or eating food exposed to contaminated water. • Cholera
• Giardiasis
• Legionnaires’ Disease /Pontiac Fever
• Leptospirosis
• Typhoid Fever
Sexually Transmitted Disease
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HIV/AIDS, chlamydia, gonorrhea, and syphilis are the predominant sexually transmitted infections.
• Chlamydia
• Genital warts
• Gonorrhea
• Hepatitis A, B, and C
• Herpes
• Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome (HIV/AIDS) • Human papillomavirus
• Syphilis
• Zika
Respiratory Viruses
Respiratory viruses are responsible for influenza-like illness. They can also cause the common cold. The virus that caused the Covid-19 pandemic is a respiratory virus. People at high risk (those with certain underlying conditions, the elderly, the very young, and pregnant women) can develop severe illness that results in hospitalization or death. The best protection is proper hygiene and avoiding contact with sick individuals. The best way for those who are infected to protect others is to cover their nose and mouth when sneezing and coughing, use good hand hygiene, and stay home from work or school.
• Adenovirus
• Coronaviruses
• Influenza
• Parainfluenza
• Parvovirus B19
• Respiratory Syncytial Virus
• Rhinovirus (Common Cold)
• Measles
• Pertussis (whooping cough)
Marin County, like the rest of the United States, was included in the March 2020 FEMA major disaster declaration for the COVID-19 coronavirus pandemic. Since March 2020, Marin County Public Health collected and analyzed information about COVID-19 impact in every community.
Figure 3.210 shows Marin County Covid-19 hospitalizations and Figure 3.211 shows Marin County Covid-19 cases, hospitalizations by demographic. 752
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Figure 3.211: Marin County Covid-19 Hospitalizations
Source: California Department of Public Health
Figure 3.212: Marin County Covid-19 Hospitalizations by Demographics Source: California Department of Public Health
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The 1918 Spanish Flu also had impacts on the Marin County OA. San Rafael city officials took action before the disease hit the rest of Marin County. All unnecessary public gatherings in social halls and fraternal lodge were prohibited in San Rafael. Schools remained open but theaters were closed. The City of San Rafael passed an ordinance authorizing the arrest of people who failed or refused to wear gauze masks when appearing on the streets. Masks were considered a necessity and ultimately the rest of the Marin County OA public was mandated to wear them. By October 24, 1918, all Marin County schools had been closed and churches and lodges were ordered to postpone all planned meetings. The first death in Marin from the flu was reported that same day “when Seth Morby, of Kentfield was taken.” The Hotel Rafael in San Rafael was used to house flu patients. A resurgence of flu cases across the Marin County OA occurred throughout much of 1919. Several additional deaths occurred and emergency measures had to be reinstated before being lifted again later in the year.
Climate Change
Climate change is expected to have an impact on health hazards. Projected increases in hot days and extreme heat events will increase the risk of heat-associated deaths. Air quality impacts and drier conditions may exacerbate respiratory and cardiovascular conditions through greater concentrations of pollution and allergens. Prolonged droughts from climate change can also affect the quality of drinking water (Centers for Disease Control and Prevention, 2020).
The California 4th Climate Assessment finds that Bay Area public health is threatened by a number of climate related changes, including more extreme heat events, increased air pollution from ozone formation and wildfires, longer and more frequent droughts, and flooding from sea level rise and high-intensity rain events. Heat waves pose increased health risks due to urban heat islands and lack of local experience and cooling infrastructure (air conditioning) in bayside cities. These risks are compounded for low-income communities.
3.4.6 TRANSPORTATION SYSTEMS
Vehicle Accident
A vehicle accident occurs when a motor vehicle collides with another vehicle or object. Vehicle collisions can result in mass fatalities and property damage. A number of factors contribute to the risk of a collision including vehicle design, speed of operation, road design, road environment, driver skill, and impairment due to drugs or alcohol. There are numerous different types of vehicle collisions; of primary concern are the ones that result in a mass fatality and/or a hazmat incident. These incidents can occur due to a single vehicle accident, such as with a tour bus or a truck carrying hazardous materials, or due to a multi-vehicle accident. Multi-vehicle collisions generally occur on high capacity and high-speed routes such as freeways. The only interstate in the Marin County OA is Interstate 580 which connects Marin County to Contra Costa County via the Richmond-San Rafael Bridge. There are several major state highways that traverse the Marin County OA including Highways 101, 1 and 37. See figure 3.212 for a map of roadways in the Marin County OA.
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Figure 3.213: Marin County Highways
Source: Marin Convention and Visitors Bureau
Multi-vehicle accidents usually occur in low-visibility conditions. Marin County often experiences fog which can hamper visibility. Road hazards, including black ice and landslides, can cause multi-vehicle accidents in good visibility. On roads with high traffic volume, a chain-reaction crash can occur when motorists are unable to stop. Determining the cause of multi-vehicle accidents is often difficult. Multi-vehicle accidents are particularly deadly due to the heightened risk of injury and chances of a fire occurring. Multi-vehicle accidents can also overwhelm local responding units, making rescue more difficult. Accidents in remote areas can hamper the 755
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ability to receive medical help. A mass fatality and/or hazmat incident could occur on any one of Marin County’s major highways.
In March 2006, a freak blizzard with two to four inches of slush caused a 28-car pileup on Highway 101 at the then Waldo Tunnel. Two people were killed and more than a dozen injured, and the northbound lanes were closed for 11 hours. The pileup scattered wreckage 350 to 400 feet along the road.
In December 2022, a Marin Transit bus overturned in rainy weather in San Rafael but there was only one person aboard.
Train Accident
A train accident is a violent and destructive crash involving a train. There are several different kinds of train accidents that can occur. A train can derail due to defects in or the compromising of track infrastructure, human error, mechanical or maintenance issues on the train itself, and/or from hitting another object such as a vehicle or another train. A train can also hit another object without derailing. Train accidents can be classified in terms of both cause and effect:
Classification of train accidents by cause:
Engineer/Conductor Error
• Passing signals at danger
• Excessive speed
Mishandling of the engine
• Failure to check brakes and safety systems
• Failure to stop at required positions
Controller Error
• Allowing two trains into the same occupied block section • Other Railway Personnel Error (shunters, porters, maintenance workers) • Accidental track obstruction
• Improper maintenance activities (leading to warped rails, damaged ties, faulty signals, etc.)
Mechanical Failure of Rolling Stock (Train Cars)
• Poor maintenance
• Poor design
• Undetected damage
• Overloading of or improperly secured freight
• Combustion fire
Civil Engineering Failure
• Track faults
• Bridge and tunnel collapses
• Poor track or junction layout
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Non-Railway Personnel Error
• Accidental track obstruction
Deliberate Acts
• Deliberate track obstruction
• Intentional damage to track infrastructure or the train itself • Level crossing misuse
Natural Causes
• Track obstruction due to landslides, avalanches, floods, or felled trees • Fog or snow that can obscure signals or the position of a train • Wet leaves
Classification of Train Accidents by Effect:
Collision (any of which can cause a derailment)
• Head-on collision
• Rear collision
• Slanting collision
• Collision with buffer stops
• Collision with obstructions of the track
Derailment
• Plain track
• Curve
• Junction
Other
• Fires, explosions, and release of hazardous chemicals • People falling from trains
A train accident can cause significant loss of life and/or property and environmental damage depending on the severity of the accident and the type of materials involved. In addition to hazardous commodities being transported, fuel tanks on locomotives can also cause a fire and/or an environmental hazard.
The Sonoma-Marin Area Rail Transit (SMART) is the North Bay’s passenger rail service for Marin County. SMART is a Class 4 railroad. The current 45-mile system includes stations in Novato, San Rafael, and Larkspur. SMART’s system also includes a bicycle and pedestrian pathway along the rail corridor. SMART also provides freight service to North Bay businesses in Marin County on the same line. SMART Freight operates on the historic rail corridor constructed by Southern Pacific Railroad in the late 1800s and later utilized by Northwestern Pacific Railroad (NWP) beginning in 1914. See Figure 3.213 for a map of the SMART commuter and freight line.
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Figure 3.214: SMART Commuter and Freight Line
Source: SMART
There are currently 24 bridges in the segment of the SMART line from San Rafael to Santa Rosa in Sonoma County as well as 63 at grade crossings. A positive train control system was implemented for the length of the service corridor for customer and pedestrian safety.
The SMART commuter fleet consists of nine two-car Nippon Sharyo DMU trainsets. Each DMU car is powered by a Cummins QSK19-R diesel engine. Trains may be as long as station platforms provided there are cabs facing the outer ends. Each two-car train has room for over 300 passengers. Trains operate 19 round trips on weekdays at an average of 34.1 miles per hour. SMART freight trains do not transport hazardous materials and currently carry grain, food supplies and lumber.
On March 19th, 2023, a SMART freight train carrying corn tipped over in Sonoma County after heavy rainfall saturated the railroad tracks. Several cars derailed. There were no injuries.
On February 10th, 2023, a SMART commuter train hit a car in Novato, killing a woman. No passengers on the train were injured.
On September 17th, 2020, a SMART commuter train hit a car in San Rafael, injuring a woman.
No passengers on the train were injured.
A July 2016 fire aboard one of Toronto's Nippon Sharyo units revealed a design flaw in the engine's crankshaft that would result in premature wear. SMART delayed operations until the engines could be serviced to correct the problem.
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In December 2014, rains washed away some of the SMART train track beds near Petaluma in Sonoma County, but the trains were not running.
Airplane Accident
An airplane accident is an occurrence associated with the operation of an airplane where a person is fatally or seriously injured and where the aircraft sustains damage or loss. Airplane accidents can occur as a result of pilot error, mechanical issues associated with aircraft, terrorism, weather, or other human error. The majority of airplane accidents and fatalities occur before or during takeoff and during approach or landing.
There are two airports, two heliports and a seaplane base in Marin County, though none of them serve commercial flights. They are all private with the exception of the Gnoss Field Airport which is operated by Marin County Public Works.
Gnoss Field Airport - DVO
Novato, California
San Rafael Airport - CA35
San Rafael, California
San Rafael Private Heliport - 5CA3
San Rafael, California
Commodore Center Heliport - JMC
Sausalito, California
Commodore Center Seaplane Base - 22CA
Sausalito, California
There could be numerous different impacts from an airplane crash in the Marin County OA. The worst-case scenario would be if a large commercial aircraft were to crash in any heavily populated area of the OA resulting in a mass casualty incident and significant damage on the ground. The chances of this occurring are small. The most likely significant event would be a small to medium size airplane having an incident in a heavily populated area of the OA.
On July 8th 2023, a single-engine Cessna 172 plane crashed near San Rafael Airport. The plane’s tail hit power lines before the plane struck the ground. One person was killed.
On May 9th, 2022, a fixed-wing, single-engine Vans RV-10 plane crashed into a hillside near the Golden Gate Bridge. At the time of the crash, the area was surrounded by thick fog. Two people were killed.
On May 16th, 1946, a U.S. Army B-17 Flying Fortress aircraft crashed into White's Hill near Fairfax, California. Two people were killed and six seriously injured.
Ship Accident
A ship accident is a marine event that occurs directly in connection with the operation of a ship and results in loss of life, environmental damage, material damage to a ship, and/or the total loss of a ship. Ship accidents can occur as a result of a fire, explosion, collision, grounding/shoaling, contact, heavy weather damage, hull cracking, or hull defect that can result in the immobilization of main engines, penetration of the ship, extensive structural damage, 759
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and/or a breakdown that necessitates towing assistance. A ship accident can occur with both cargo and passenger ships.
Since the closure of the Marinship shipyard, Marin County does not have a marine port. There are several ferry terminals in Marin County that cater to passenger vessels:
Larkspur Landing, also known as the Larkspur Ferry Terminal, serves the Golden Gate Ferry which travels to two locations in San Francisco.
The Tiburon Ferry Terminal serves the Golden Gate Ferry which travels to two locations in San Francisco and the Angel Island–Tiburon Ferry Company for ferry service to Angel Island State Park.
The Sausalito Ferry Terminal serves the Golden Gate Ferry and the Blue & Gold Fleet which both travel to San Francisco.
The Golden Gate Ferry has a fleet of four catamarans and three monohull vessels. The monohull vessels are named M.S. Marin, M.S. San Francisco, and M.S. Sonoma. The Marin can carry 750 passengers, and the San Francisco and Sonoma can carry 630 passengers each.
The catamarans are named the M.V. Del Norte, M.V. Golden Gate, M.V. Mendocino, and M.V.
Napa. The Del Norte has a capacity of 400 passengers while the other three vessels have a capacity of 450 passengers. The Blue & Gold Fleet operates a fleet of 21 vessels, the largest of which can hold approximately 450 people. The Angel Island Tiburon ferry operates three vessels, the largest of which can hold 400 people.
There are numerous public and private marinas and boating facilities in the Marin County OA along San Francisco Bay, Richardson Bay and Tomales Bay that serve smaller passenger watercraft and commercial fishing vessels.
The most significant maritime incident that could occur in the Marin County OA would be from a large ferry at full capacity having an incident in San Francisco or Richardson Bay or at one of the ferry terminals.
On November 23rd, 2018, a ferry carrying 53 passengers from Larkspur to San Francisco crashed into the dock at the San Francisco Ferry Terminal. Two people on board were injured.
Both the ferry and the San Francisco Ferry Building dock sustained damage in the crash. 760
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SECTION 4.0: MITIGATION STRATEGY
Mitigation projects that address the goals and objectives developed in the previous section were identified, evaluated, and prioritized. These actions form the core of the hazard mitigation plan. A capabilities assessment was conducted by Marin County and its participating jurisdictions, reviewing existing local plans, policies, and regulations for any other capabilities relevant to hazard mitigation planning. An analysis of their capability to carry out these implementation measures with an eye toward hazard and loss prevention was conducted.
The capabilities assessment required an inventory of each jurisdiction’s legal, administrative, fiscal and technical capacities to support hazard mitigation planning. After completion of the capabilities assessment, each jurisdiction evaluated and prioritized their proposed mitigations.
Each jurisdiction considered the social, technical, administrative, political, legal, economic, and environmental opportunities and constraints of implementing a particular mitigation action. This step resulted in a list of acceptable and realistic actions that address the hazards identified in each jurisdiction.
4.1 CHANGES IN DEVELOPMENT
Overall hazard vulnerability has remained unchanged over the past 5 years due to development and population changes. Marin County development and populations have increased in some cities and decreased in several others over the last 5 years. Overall vulnerability and risk reduction has been achieved through carefully planned development and application of the capabilities detailed in Section 4.3 CAPABILITY ASSESSMENT. 44 CFR Requirement §201.6(c)(3) [The plan shall include the following:] A mi�ga�on strategy that provides the jurisdic�on’s blueprint for reducing the poten�al losses iden�fied in the risk assessment, based on exis�ng authori�es, policies, programs, and resources, and its ability to expand on and improve these exis�ng tools.
§201.6(c)(3)(i) [The hazard mi�ga�on strategy shall include a] descrip�on of mi�ga�on goals to reduce or avoid long‐term vulnerabili�es to the iden�fied hazards. §201.6(c)(3)(ii) [The hazard mi�ga�on strategy shall include a] sec�on that iden�fies and analyzes a comprehensive range of specific mi�ga�on ac�ons and projects being considered to reduce the effects of each hazard, with par�cular emphasis on new and exis�ng buildings and infrastructure. All plans approved by FEMA a�er October 1, 2008, must also address the jurisdic�on’s par�cipa�on in the NFIP, and con�nued compliance with NFIP requirements, as appropriate. §201.6(c)(3)(iii) [The hazard mi�ga�on strategy shall include an] ac�on plan, describing how the ac�on iden�fied in paragraph (c)(3)(ii) of this sec�on will be priori�zed, implemented, and administered by the local jurisdic�on. Priori�za�on shall include a special emphasis on the extent to which benefits are maximized according to a cost benefit review of the proposed projects and their associated costs.
§201.6(c)(3)(iv) For mul�‐jurisdic�onal plans, there must be iden�fiable ac�on items specific to the jurisdic�on reques�ng FEMA approval or credit of the plan. §201.6(c)(4)(ii) [The plan shall include a] process by which local governments incorporate the requirements of the mi�ga�on plan into other planning mechanisms such as comprehensive or
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Marin County is a county located in the northwestern San Francisco Bay Area. As of the 2020 census, the population was 262,231. Its county seat and largest city is San Rafael. Marin County is across the Golden Gate Bridge from San Francisco and is included in the San Francisco–Oakland–Berkeley, CA Metropolitan Statistical Area.
Unincorporated Marin County includes most of West Marin, which borders the Pacific Coast and is the most rural part of the county, with Golden Gate National Recreation Area and the Point Reyes National Seashore occupying much of the area and small communities mixed throughout. There are also pockets of unincorporated areas along the central, Highway 101 corridor and the San Francisco Bay shoreline. Altogether, there are 22 distinct communities within unincorporated Marin County.
According to the U.S. Census, the population in unincorporated Marin is 66,987. While population in both the unincorporated County and the County grew in the first half of the 2010s, since 2017 the population has decreased in both areas, with the most significant drop occurring in the most recent year. Between 2020 and 2021, the population in the unincorporated County decreased by 2.6%, over twice as much as in the County as whole (1.2%). The Association Bay Area of Governments (ABAG) projects that the population in the unincorporated County will grow by only 2% in the next two decades.
Based on 2021 data from the California Department of Finance (DOF), the unincorporated area of Marin has 24,778 single-family homes constituting 83% of the total housing stock, 4,452 multi-family homes comprising 15% of all housing, and 588 mobile homes, for a total of 29,818 homes. The beauty of the natural landscape helps define the character of the community, but it also presents risk of natural hazards that present challenges to locating and building new housing, which have been skillfully met in the 2023 update to Marin County’s Housing Element.
The Regional Housing Needs Assessment (RHNA) allocation for unincorporated Marin for the 2023-31 planning period has been determined by ABAG to be 3,569 housing units, including 550 units for extremely low income, 550 units for very low-income households, 634 units for low-income households, 512 units for moderate-income households, and 1,323 units for above moderate-income households.
Table 4.1 presents entitled projects and pending entitled projects in unincorporated Marin County.
Table 4.1: Unincorporated Marin County Future Growth Areas Development # of
Units
# of
Parcels
Project
Date Acres
Fire
Severity
Zone
Flood
Zone
North Knoll Rd/Saint Thomas Dr 59 2 N/A 3.7 NA NA
Pan Pac Ocean Site 32 4 N/A 16 NA NA
Strawberry Commercial 60 4 N/A 2 NA NA
Strawberry Rec District Site 46 1 N/A 2.3 NA NA
Strawberry Village Center 100 2 N/A 3.3 NA NA
Oak Manor Commercial Center 36 2 N/A 1.6 NA NA
Kentfield Commercial
Underutilized
71 12 N/A 2.4 Moderate AE
Sloat Garden Center 31 2 N/A 1.1 NA AO
Marin County Juvenile Hall 80 1 N/A 2.7 High NA
Marinwood Plaza 125 4 N/A 125 High NA
Office Building (Across from
Juvenile Hall)
58 1 N/A 2.32 High NA
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St. Vincents 680 3 34 NA NA
Marin Gateway Center 100 1 5 NA X02
MLK Academy School 63 1 6 High NA
825 Drake 74 1 Moderate NA
Atherton Corridor 147 4 7.4 Moderate NA
Black Point (Vacant) 58 1 14.5 Moderate NA
Buck Center Vacant Property 249 2 12.5 NA NA
Greenpoint Nursery 53 1 3.5 Moderate AE
Bernard Osher Marin Jewish
Community Center
49 4 1.6 Moderate NA
Cal Park 110 11 3.7 NA AE
Church of Jesus Christ 35 1 1.2 Moderate NA
McPhail School 33 3 1.1 NA AE
Old Gallinas Children Center 50 1 1.7 Moderate NA
San Quentin Adjacent Vacant
Property
230 1 7.7 NA NA
Office – Lagunitas (Upper
Floors and Rear Prop)
30 2 1.5 Moderate NA
San Domenico School 50 1 1.7 High NA
Sacramento/San Anselmo
Properties
64 4 2.1 Moderate –
NA
NA
Holiday Inn Mill Valley 72 1 2.4 NA AE
Jack Krystal Hotel Parcel Site 36 1 1.2 NA AE
Shoreline Unified School
District
44 2 2.2 Moderate NA
Olema Underutilized 36 4 3.6 Moderate –
NA
AE
Pt Reyes Coast Guard
Rehabilitation/Conversion
50 1 10 Moderate NA
Pt. Reyes County Vacant Site 37 2 1.9 Moderate NA
Shoreline Unified School
District
44 2 2.2 Moderate NA
Tomales (Vacant) 30 5 32 Moderate NA
Total 3,122 95
Table 4.1: Unincorporated Marin County Future Growth Areas Source: Marin County Department of Community Development
4.2 CHANGES IN PRIORITIES
The overall hazard mitigation priorities in Marin County and its participating jurisdictions have not changed since the 2018 MJHMP update. However, the strategies that support the overall county priorities have changed since the 2018 MJHMP and are reflected in the sections below.
There were many projects that were either ongoing day-to-day activities or were response related that were deleted from the 2018 MJHMP project list and not carried over to this plan update. Several actions were completed, and new projects were added to coincide with the changes in priorities, progress in local mitigation efforts and changes in development.
4.2.1 VULNERABILITY AND RISK REDUCTION
All new development occurring in the future growth area identified in Table 4.1 will provide hazard vulnerability and risk reduction for the county. This reduction will occur due to the anticipated improvements and investments implemented in the 2023 revisions to the Marin County General Plan. In addition, any new development will comply with the most up-to-date building codes and use the latest techniques, further reducing vulnerabilities throughout the County.
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4.3 CAPABILITY ASSESSMENT
Capabilities are the programs and polices currently in place to reduce hazard impacts or that could be used to implement hazard mitigation activities. The capability assessment identifies the local planning mechanisms where information from the 2018 MJHMP is incorporated and where updated hazard mitigation information from this 2023 MJHMP will be incorporated once approved. The capability assessment is divided into four sections: regulatory, administrative and technical, fiscal, and outreach and partnerships.
4.3.1 REGULATORY CAPABILITIES
The legal and regulatory capabilities include existing ordinances and codes that affect the county’s or city’s physical or built environment. Examples of legal and/or regulatory capabilities can include: a jurisdiction’s building codes, zoning ordinances, subdivision ordnances, special purpose ordinances, growth management ordinances, site plan review, general plans, capital improvement plans, economic development plans, emergency response plans, and real estate disclosure plans. The table below lists regulatory mitigation capabilities, including planning and land management tools, typically used by local jurisdictions to implement hazard mitigation activities and indicates those that are in place.
Table 4.2: Legal and Regulatory Capabilities
Plans
Yes/No
Latest
Update
Does the plan/program address hazards?
Does the plan identify projects to include in the mitigation strategy?
Can the plan be used to implement mitigation actions?
Countywide Plan: Water
Resources, Environmental
Hazards, and Public Safety
Sections
Y
2023
Describes hazard areas and regulates current and future development based on known hazard areas.
Expansion and Improvement: The HMP will be informed
by referencing the Safety Element of the General Plan. The City will adopt the approved HMP as part of the General Plan Safety Element to meet the requirements of AB 2140.
Local Coastal Program Y
2023
Pursuant to the California Coastal Act, Marin County’s Local Coastal Program guides land use and development to
ensure protection of public access and other coastal
resources along Marin County’s Pacific coastline.
Expansion and Improvement: Included is a hazards
section with policies that guide development standards and project review for areas subject to hazards including
flooding, bluff retreat, earthquakes, and coastal erosion.
County Emergency
Operations Plan
Y
2018
This plan describes what the County’s actions will be during a response to all hazards. Includes annexes that describe in more detail the actions required of departments/agencies.
Further, this plan describes the role of the Emergency
Operation Center (EOC) and the coordination that occurs between the EOC and the local jurisdiction’s departments and other response agencies.
Expansion and Improvement: This plan may be used for
mitigation in that it describes risk and vulnerability in the county.
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Area Housing Authority
Organizational Emergency
Response Plan
Y
Enhances the Area Housing Authority’s ability to effectively respond to emergencies by establishing procedures and
assigning responsibilities.
Expansion and Improvement: This plan may be used for
mitigation in that it describes risk and vulnerability in the county.
Strategic Plan No
Capital Improvements Plan
Y
2021
The Capital Improvement Plan (CIP) was developed
through collaboration between Capital Project staff of
Public Works (DPW) and the County Administrator’s
office. Significant input was provided by multiple County departments, special districts, and enterprise funds of outside the general County General Funds. The CIP
presents the proposed funding for the fiscal year (FY) of 2021-2022 to improve four key areas. Facility
improvements, water resources, road infrastructure, and airports. Expansion and Improvement: CIP identifies
potential hazard mitigation projects.
Economic Development
Plan
Y
2022
The Marin County Economic Vitality Strategic Plan
outlines “Flagship Initiatives” that the County of Marin and community partners will pursue over the next 5 years.
Ultimately, the actions taken are intended to create a
dynamic economy, providing equitable access to good
jobs, opportunities for new business creation and a high quality of life for all Marin’s residents.
Expansion and Improvement: The plan has a strong
focus on the impact of Covid-19 on the local economy, so may be used to show how disasters impact Marin’s
businesses and workforce, but does not have mitigation
projects.
Continuity of Operations
Plan
N
Flood Safety Plan Y Plan addresses flood hazard response, not mitigation. It was created in 2018 and a 2023 update is in progress.
Engineering Studies for
Streams
Y
There are many existing studies on marinflooddistrict.org.
A study of Novato Creek is currently underway.
Expansion and Improvement: These studies do identify
potential hazard mitigation projects.
Open Space Management
Plan
Y
Marin County Parks holds numerous plans that guide
open space management: Strategic Plan, Road and Trail
Management Plan, Vegetation and Biodiversity
Management Plan, Inclusive Access Plan.
Expansion and Improvement: Some of these plans
contain guidance for mitigation projects and will be aligned with the MJHMP to describe developmental trends,
hazards, and potential development in hazard areas.
Regional Transportation
Plan (RTP)
Y
2021
The Transportation Authority of Marin (TAM) participates in the nine-county Metropolitan Transportation
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Commission, which adopted Plan Bay Area 2050. The
plan outlines strategies spread across transportation,
housing, the economy and the environment that seek a
more equitable Bay Area.
Expansion and Improvement: The plan does outline
regional strategies for mitigation that may be used in
Marin.
Stormwater Management
Plan/Program
Y
2022
SWRP is a watershed-level resource planning document
covering the County and Marin’s 11 cities that describes watershed issues, identifies project opportunities with multiple benefits, and creates a prioritized list of project opportunities based on quantifying multiple benefits.
Expansion and Improvement: The Plan will be aligned
with the MJHMP in describing and developing mitigation
actions to address climate change and drought. Water
demand reduction strategies contained in the plan should be considered for inclusion as mitigation activities in the MJHMP.
Repetitive Loss Area
Analysis Y
On July 18, 2023, an expanded and updated multijurisdictional analysis was adopted by the County Board of Supervisors.
Community Wildfire
Protection Plan
Y
2020
CWPP addresses wildfire risk and mitigation measures to take throughout the county.
Expansion and Improvement: The plan can be used to
support and guide mitigation efforts.
Other special plans (e.g.,
brownfields redevelopment,
disaster recovery, coastal
zone management, climate
change adaptation)
Y
25 Community and area plans within Marin. Climate change adaptation policies and programs in Countywide Plan
Safety, Element/Environmental Hazards section. Policies and programs address sea level rise, flooding, extreme heat, wildfire, equitable safety planning for vulnerable populations.
Building Code, Permitting,
and Inspections Y/N Are codes adequately enforced?
Building Code Y
Yes, the Community Development Agency established a
code compliance program to ensure adherence with the
County’s law and regulations related to zoning,
construction, and environmental health.
Expansion and Improvement: Adherence to building
codes, including local codes, regulates growth and
controls land use patterns. Addressing known hazards, as codes are updated, results in lowered risk and potentially fewer losses.
Building Code
Effectiveness Grading
Schedule (BCEGS) Score
Y 3
Yes, codes are adequately enforced. The County’s score
is 3.
Fire department ISO rating: Y 3/3X
The County’s ISO Rating is 3/3x; to be rated a “3” the parcel must be within 1000-ft of a municipal fire hydrant and 5- miles from a fire station. If either of those criteria are not met, the parcel is 3x (the old 9). Furthermore, per the State, if the parcel is more than 5-miles from a fire station, the parcel is rated “10”. Yes, our codes are adequately
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enforced.
Site plan review
requirements Y
Yes, this is adequately achieved.
Land Use Planning and
Ordinances Y/N
Is the ordinance an effective measure for reducing
hazard impacts?
Is the ordinance adequately administered and enforced?
County Code of Ordinances Y
The purpose of this code is to establish the minimum
requirements to safeguard the public health, safety, and general welfare through structural strength, means of
egress facilities, stability, access to persons with
disabilities, sanitation, adequate lighting and ventilation and energy conservation, and safety to life and property from fire and other hazards attributed to the built
environment; to regulate and control the demolition of all buildings and structures, and for related purposes.
Expansion and Improvement: Adherence to local
ordinances regulates growth and enforces standards.
Addressing known hazards, as codes are updated,
results in lowered risk and potentially fewer losses.
Zoning ordinance Y
2023
Zoning ordinances are regularly updated (last update
2023).
Yes, they are adequately administered and enforced.
Expansion and Improvement: Adherence to local
ordinances regulates growth and enforces standards.
Addressing known hazards, as codes are updated,
results in lowered risk and potentially fewer losses.
Subdivision ordinance Y
Yes, the ordinance is adequately administered and
enforced. It is regularly updated (last update 2023).
Expansion and Improvement: Adherence to local
ordinances regulates growth and enforces standards.
Addressing known hazards, as codes are updated,
results in lowered risk and potentially fewer losses.
Floodplain ordinance Y
Marin County Code 23.09 Floodplain Management.
Ordinance 3293 Sec 1, 1999
Expansion and Improvement: Adherence to local
ordinances regulates growth and enforces standards.
Addressing known hazards, as codes are updated,
results in lowered risk and potentially fewer losses.
Natural hazard specific
ordinance (stormwater,
steep slope, wildfire)
Hazards are addressed in the Development Code, Title
22. Regularly updated. Expansion and Improvement:
Adherence to local ordinances regulates growth and
enforces standards. Addressing known hazards, as
codes are updated, results in lowered risk and potentially fewer losses.
Flood insurance rate maps Y
Hard copies of the FEMA Flood Insurance Rate Maps
(FIRM) are maintained in the DPW Land Development
office. Electronic copies are available on MarinMap.org.
Expansion and Improvement: The maps can be used
to support and guide mitigation efforts.
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Elevation Certificates
Elevation Certificates are required for all new and
substantially remodeled structures. Hard copies of all
Elevation Certificates since 1982 are maintained in the DPW Land Development office.
Expansion and Improvement: The certificates can be
used to support and guide mitigation efforts.
Acquisition of land for open
space and public recreation
uses
Y
The County of Marin is committed to continuing to
preserve open space.
Expansion and Improvement: As a member of Together
Bay Area, the County has prioritized purchasing multiple open space properties to that may be used as open space preserves and recreation space.
Erosion or sediment
control program Y
Requires property owners to have effective Best
Management Practices in place to control pollutants in
runoff from certain earth-disturbing activities.
Expansion and Improvement: The program can be
used to support and guide mitigation efforts.
Table 4.2: Marin County Legal and Regulatory Capabilities Source: Marin County
Plans
Marin General Plan
California Government Code 65300 requires that every City and County in the state have a General Plan. The Marin General Plan, adopted in 2007, was prepared over a multiyear period that included an extensive public review process. The Marin General Plan was updated in 2015, with the Housing and Safety Elements updated in 2023. The Marin General Plan is the most important policy and planning document in the county and is used by virtually every department. The Marin General Plan is the County's statement of its vision for the future. The Marin General Plan contains policies covering every aspect of the County: land use (how land can be developed), circulation, noise, air quality, housing, open space and conservation, and health and safety.
Marin County specific goals and policies related to mitigation of natural hazards are as follows:
44 CFR Requirement §201.6(c)(4)(ii) [The plan shall include a] process by which local governments incorporate the requirements of the mi�ga�on plan into other planning mechanisms such as comprehensive or capital improvements, when appropriate. 768
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Table 4.3: County of Marin General Plan
Goal/Policy/
Program Explanation
Land Use Element
Goals
The requirements of the land use element are met in the following sections of the General Plan: water resources, community development, planning areas. The goals for these elements are:
To support healthy watersheds and provide clean and adequate water for wildlife and humans.
To utilize the Environmental Corridor Land Use Framework, coordinate with other jurisdictions, and map land use designations.
To establish land use policies for the seven planning areas.
Policies
Overall policies for land use are intended: to protect, improve, and restore resources, including, directing land use to appropriate areas, reducing impacts, establishing land use designations and categories, and setting land use standards.
Programs
Programs for land use include, setting standards, monitoring and assessing programs, coordinating with other jurisdictions, following best practices, maintaining urban, agricultural, and natural corridors, consider amending urban service areas preserve resources, consider sea level rise. Programs also include, updating plans, reviewing codes, and revising zoning maps.
Conservation and Open Space Element
Goal To sustainably manage and preserve open space and biological resources for the benefit of the environment and Marin residents.
Policy
Policies for Conservation and Open Space include; support efforts and continue to acquire open space, balance shoreline protection and access, protect natural resources, support vegetation and wildlife disease management, control non-native plants and species, and restrict use of toxic chemical substances in habitats.
Program
Conservation programs include mapping natural communities, developing monitoring programs, and partnering with local actors.
Open space programs include, coordinating with partners, establish compatible policies, inform and enforce, research, and acquire and protect lands.
Safety Element
Goals To reduce risk, increase safety, and bolster resilience in an equitable manner.
Policies
Policies in the Safety Element are to represent an inclusive, community-led approach to bolstering resilience. Furthermore, policies are evidence of an all-hazard informed, approach to protection, planning, and regulation.
Programs
Programs in the Safety Element include specific outreach and support to vulnerable populations, working with local leaders, coordinating with private and public partners, improving hazard information sharing with residents, improving infrastructure and systems to support/improve emergency response, and utilizing planning functions.
Public Facilities Element
Goal To provide adequate public facilities and services to accommodate the level of development planned by cities and towns and the County.
Policies
Policies to support the County’s Public Facility Element include requiring cost sharing, effective planning, discouraging privatization, and reducing demand on public facilities.
Programs
Programs include requiring fair share contributions, planning for service expansion, preparing naming and sponsorship guidelines, and reducing demand on public facilities.
Table 4.3: Marin County Goals and Policies
Source: Marin County General Plan
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4.3.2 ADMINISTRATIVE AND TECHNICAL CAPABILITIES
The administrative and technical capability assessment identifies the personnel responsible for activities related to mitigation and loss prevention in Marin County. Many positions are full time and/or filled by the same person.
Table 4.4: Administrative and Technical Capabilities
Administrative Yes/No Is coordination effective?
Planning Commission
Y Administrative Services Division handles finance and
purchasing, budgeting, risk management, information
technology, and business licensing for the community.
The department may be responsible for implementing
mitigation actions related to the department’s scope.
Expansion and Improvement: Prioritize new initiatives
that support mitigation activities within the county.
Marin Operational Area
Hazard Mitigation Working
Group
Y The County participates in the Marin Operational Area Hazard Mitigation Working Group that meets quarterly to review and manage Hazard Mitigation projects and
programs. The Hazard Mitigation Committee is the
supporting branch of the disaster council.
Expansion and Improvement: Prioritize new initiatives
that support mitigation activities within the County.
Maintenance programs to
reduce risk (e.g., tree
trimming, clearing
drainage systems)
Y Many Flood Zones have creek and drainage
maintenance programs. These only cover a small portion
of creeks in the County, where residents formed a flood zone and where a project was initiated and right of way acquired by the Marin County Flood Control & Water
Conservation District. Under the guidelines of the 2020 Pacific Gas and Electric Wildfire Mitigation Plan, PG&E will assist with mitigation efforts by clearing trees.
Expansion and Improvement: The Marin Wildfire
Prevention Authority will provide funding and educational programs on best practices for prevention efforts. Brush clearance and controlled burns will assist with mitigation efforts.
Mutual aid agreements Y Fire, Law, PW, Water agencies, MHOAC Technical
Yes/No Has capability been used to assess/mitigate risk in the past?
Warning systems/services
(Reverse 911, outdoor
warning signals)
Y Utilizes the emergency warning systems through the EAS system as their primary warning capability. Utilizes the emergency warning systems through telephone, text, and
email notification utilizing reverse 911.
Expansion and Improvement: To ensure the
effectiveness of the emergency warning system and
proper community response, monthly LRAD testing, and
IPAWs drills are required.
Hazard data and
information
Y Yes, previous and new mitigation projects are informed by hazard data and information.
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Grant writing Y Yes
Hazus analysis N
Staff/Personnel Resources
Yes/No
Full
Time/
Part
Time
Is staffing adequate to enforce regulations?
Is staff trained on hazards and mitigation?
Is coordination between agencies and staff effective?
Chief Building Official Y/PT Yes
Expansion and Improvement: Integrate mitigation
actions and strategies into the Capital Improvements
Program and annual budgeting.
Planner(s), engineer(s) and
technical staff knowledge
of land development, land
management practices,
and natural hazards.
Y/FT Develops and maintains the General Plan, including the Safety Element.
Develops area plans based on the General Plan, to provide more specific guidance for the development of more specific areas.
Reviews private development projects and proposed capital improvements projects and other physical projects involving property for consistency and conformity with the General Plan.
Anticipates and acts on the need for new plans, policies, and Code changes.
Applies the approved plans, policies, code provisions, and other regulations to proposed land uses.
Expansion and Improvement: Provide opportunities for
continued education to staff to maintain knowledge of new code and regulatory requirements.
Engineer(s), Building
Inspectors/Code
Enforcement Officers or
other professional(s) and
technical staff trained in
construction requirements
and practices related to
existing and new
buildings.
Y/FT
Oversees the effective, efficient, fair, and safe
enforcement of the California Building Code
Expansion and Improvement: Provide opportunities for
continued education to staff to maintain knowledge of
new code and regulatory requirements.
GIS Coordinator Y/FT Yes
Community Development
Staff
Y/FT Develops and maintains the General Plan, including the Safety Element. Develops area plans based on the
General Plan, to provide more specific guidance for the development of more specific areas. Reviews private
development projects and proposed capital
improvements projects and other physical projects
involving property for consistency and conformity with
the General Plan.
Expansion and Improvement: Provide opportunities
for continued education to staff to maintain knowledge
of new code and regulatory requirements.
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Engineer(s), project
manager(s), technical staff,
equipment operators, and
maintenance and
construction staff.
Y/FT
Maintains and operates a wide range of local
equipment and facilities as well as providing assistance to members of the public. These include providing
sufficient clean fresh water, reliable sewer services,
street maintenance, storm drainage systems, street
cleaning, streetlights and traffic signals.
Expansion and Improvement: Provide opportunities
for continued education to staff to maintain knowledge
of new code and regulatory requirements.
Floodplain Administrator
Y/FT Reviews and ensures that new development proposals do not increase flood risk, and that new developments
are not located below the 100 year flood level. In
addition, the Floodplain Administrator is responsible for planning and managing flood risk reduction projects
throughout the unincorporated county.
Expansion and Improvement: Provide opportunities
for continued education to staff to maintain knowledge
of new code and regulatory requirements.
Emergency Management
Y/FT Maintains and updates the Emergency Operations Plan for the county. In addition, coordinates local response and relief activities within the Emergency Operation
Center, and works closely with local, state, and federal partners to support planning and training and to
provide information and coordinate assistance.
Expansion and Improvement: Develop a quarterly
countywide emergency management and hazard
mitigation coordination meeting.
Procurement Services
Manager
Y/FT Provides a full range of municipal financial services, administers several licensing measures, and functions as the county’s Procurement Services Manager.
Marin County Sheriff’s
Office Staff
Y/FT Yes, the Marin County Sheriff’s Office is
comprehensively staffed and trained on hazards. In
addition to field services, the responsibilities of the Sheriff’s Office include maintaining the county jail,
providing security to the Superior Court, operating a
countywide communications division, operating a
documentary services division consisting of records,
warrants, civil units, and more.
Expansion and Improvement: Proactively identify
opportunities to coordinate and collaborate with
neighboring jurisdictions to increase County and regionwide capabilities.
Marin County Fire Staff
Y/FT The Marin County Fire has responsibility for fire
suppression and emergency response in commercial,
residential, wildland / urban interface. The Marin County Fire supports implementation of mitigation actions that reduce the risk of wildfire.
The Marin County Office of Emergency Management, a
division of the County Fire Department, conducts
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emergency preparedness activities for the community.
Mitigation activities related to emergency preparedness can be implemented by OEM in partnership with other
county partners.
Expansion and Improvement: Proactively identify
opportunities to coordinate and collaborate with
neighboring jurisdictions to increase County and regionwide capabilities.
Table 4.4: Marin County Goals and Policies
Source: Marin County General Plan
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4.3.3 FISCAL CAPABILITIES
The fiscal capability assessment shows specific financial and budgetary tools available to Marin County such as community development block grants; capital improvements project funding; authority to levy taxes for specific purposes; fees for water, sewer, gas, or electric services; impact fees for homebuyers or developers for new development; ability to incur debt through general obligations bonds; and withholding spending in hazard-prone areas.
Table 4.5: Marin County Fiscal Capabilities
Financial Yes/No
Has the funding resource been used in past and for what type of activities?
Could the resource be used to fund future mitigation
actions?
Capital improvements
project funding Y Yes, Capital Improvements Project funding has been used in the past and can be used for future mitigation projects.
Authority to levy taxes for
specific purposes
Y
Post Prop 13 and Prop 218 the success in levying taxes
for mitigation projects has been significantly reduced.
Many flood-prone areas historically relied on special taxes to build out levee improvements and pump stations. In the last 20 years (a total of 4) special tax measures for flood mitigation projects have not passed. In March 2020, tax Measure C was passed. The measure will raise
approximately $20 million annually to fund wildland fire hazard mitigation efforts throughout the county. Marin
Wildfire Prevention Authority (MWPA) was formed to
serve as the governing body to manage the funds raised
through Measure C funds go to public outreach,
vegetation management, fire hazard assessments, among
other projects.
Fees for water, sewer, gas, or
electric services (water - fire
flow increase, sewer, more
research on G&E)
Y
Funding has not been used in the recent past for
mitigation, but could possibly fund future mitigation
activities. For example, some Special Districts are
considering potential projects with dual water storage and flood benefit utilizing water fees.
Impact fees for new
development Y
Road and transportation related impact fees are collected in connection with building permit issuance. These funds are not available for future mitigation.
Storm water utility fee
Y
Storm water fees have been used for mitigation projects in Flood Zone 9, including: bridge replacement, pump
stations, levee evaluations, and stormwater detention
basin construction. The Zone 9 fee expires in 2027. We
are following the work of other agencies after SB 231 to see if the County would pursue it again.
Incur debt through general
obligation bonds and/or
special tax bonds N
This approach has been taken in the 1980s for flood
mitigation in Novato creek, but not recently. They typically require voter approval to levy a special tax to pay back the bonds but those have not been successful in recent years.
Incur debt through private
activities N
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Community Development
Block Grant
Y
The County has been administering the CDBG program
for 30+ years through a collaboration with the cities and towns. Funds are currently used to serve low-income
residents of Marin and address historical patterns of
segregation in our communities. Priorities for the use of funds are set through a Countywide Priority Setting
committee. Given the small amount of funds available,
less than $1.5 million countywide and many competing
needs, this may not be a viable source for mitigation
funds.
Other federal funding
programs Y
Yes, federal funding has been used for mitigation projects through Emergency Management Performance Grant and
the Hazard Mitigation Assistance Program.
State funding programs
Y
There have been several Department of Water Resources
grants in support of flood mitigation projects and there will likely continue to be in the foreseeable future.
The State Coastal Conservancy grants have funded sea
level rise adaptation.
Table 4.5: Marin County Fiscal Capabilities
Source: Marin County
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4.3.4 OUTREACH AND PARTNERSHIPS CAPABILITIES
The outreach and partnerships capability assessment shows outreach and public education programs available to the County and the County partnerships utilized to promote those programs.
Table 4.6: Marin County Community Outreach
Outreach and Partnerships Yes/No Could the program/organization help implement future mitigation activities?
Local citizen groups or non-profit
organizations focused on
environmental protection, emergency
preparedness, access and functional
needs populations, etc.
Yes
Yes, these groups can assist with informing
project plans.
Expansion and Improvement: Proactively
identify opportunities to coordinate and
collaborate with neighboring jurisdictions to
increase County and region-wide capabilities.
Ongoing public education or
information program (e.g., responsible
water use, fire safety, household
preparedness, environmental
education)
Yes
Yes, these communities can assist with
informing project plans.
Expansion and Improvement: Proactively
identify opportunities to coordinate and
collaborate with communities to increase
educational opportunities.
Natural disaster or safety related school
programs
Yes
Yes, school partners can assist with informing
project plans.
Expansion and Improvement: Proactively
identify opportunities to coordinate and
collaborate with schools to increase
educational opportunities.
StormReady certification
Yes
Marin County is a StormReady community.
Expansion and Improvement: Proactively
identify opportunities to expand participation.
Firewise Communities certification
Yes
With over 80 Firewise Communities, Marin is
the fastest growing "Firewise USA" county in
the nation. These communities can assist with
informing project plans.
Expansion and Improvement: Proactively
identify opportunities to expand participation
and increase educational opportunities.
Community Rating System Yes Marin County is a Class 6 CRS community Public-private partnership initiatives
addressing disaster-related issues
Yes
Through Marin Voluntary Organizations Active
in Disasters, the County of Marin leverages
partnerships with public-private partners for
disaster related initiatives.
Expansion and Improvement: Proactively
identify opportunities to coordinate and
collaborate.
Table 4.6: Marin County Community Outreach
Source: Marin County
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4.4 PARTICIPATION IN THE NATIONAL FLOOD INSURANCE PROGRAM Marin County has participated in the Regular Phase of the NFIP since March 1, 1982. Since then, the County has administered floodplain management regulations that meet or exceed the minimum requirements of the NFIP. Under that arrangement, residents and businesses paid the same flood insurance premium rates as most other communities in the country.
The Community Rating System (CRS) was created in 1990. Marin County has been in the CRS program since May 1, 2016. The program is designed to recognize floodplain management activities that are above and beyond the NFIP’s minimum requirements. CRS is designed to reward a community for implementing public information, mapping, regulatory, loss reduction and/or flood preparedness activities. On a scale of 10 to 1, Marin County is currently ranked Class Six community, which gives a 20% premium discount to individuals in the unincorporated Marin County Special Flood Hazard Area (SFHA), and a 10% discount to policyholders outside the SFHA.
Presently, the County manages its floodplains in compliance with NFIP/CRS requirements and implements a floodplain management program designed to protect the people and property of the County. Floodplain regulations are a critical element in local floodplain management and are a primary component in Marin County’s participation in the NFIP. As well, Marin County’s floodplain management activities apply to existing and new development areas, implementing flood protection measures for structures and maintaining drainage systems to help reduce the potential of flooding within the unincorporated Marin County.
As part of the County’s efforts to comply with NFIP, Marin County will make updates and revisions to these regulations periodically to ensure they are most effective at minimizing the threat 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 action. The County will also continue to incorporate any changes to the locations and designations of mapped floodplains into future planning documents, including future updates to this Plan.
The County will also explore opportunities to enforce or enhance County ordinances, building code, and other regulatory actions to address substantial improvements/substantial damage properties. Marin County will consider developing a Substantial Damage Management Plan.
The Marin County will continue to manage their floodplains in continued compliance with the NFIP. An overview of the Marin County’s NFIP status and floodplain management program is discussed in Table 4.7. Additional information on the Marin County’s CRS program follows.
The activities credited by the CRS program provide direct benefits to Marin County and its residents,
including:
• Enhanced public safety;
• A reduction in damage to property and public infrastructure; • Avoidance of economic disruption and losses;
• Reduction of human suffering; and
• Protection of the environment.
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The activities for which Marin County implements and receives CRS credits include:
310 Elevation Certificates – Marin County receives credit for creating Construction Certificate Management Procedures as well as to maintaining Post-FIRM elevation certificates. 320 Map Information Services – Marin County receives credit for providing map information to inquirers in all seven elements such as providing information from the FIRM necessary for flood insurance, notifying inquirers of the mandatory purchase of flood insurance for all federally backed loans, providing information regarding properties located in a floodway, sea level rise area, tsunami or dam inundation area, repetitive loss areas, and areas that should be protected such as wetlands and critical habitat.
330 Outreach Projects – Marin County has a robust outreach program and receives maximum credit for this Activity. The County mails out an annual brochure prior to the rainy season to properties in the Special Flood Hazard Area, Repetitive Loss Areas, Tsunami and Dam inundation areas and to local lenders, real estate brokerages and insurance companies. Marin County also receives credit for its social media outreach on Facebook, Twitter and NextDoor. 340 Hazard Disclosure – Marin County works with local real estate brokerages to encourage them to advise prospective home buyers of required disclosures and receives credit for this Activity.
350 Flood Protection Information – Marin County receives credit for Elements in this Activity by maintaining required information documents available in the Marin County Library catalog as well as documents that are pertinent to residents. The County also receives credit for maintaining a presence on the County Public Works website. 360 Flood Protection Assistance – Marin County receives credit for providing property protection advice. The County also provides information about available financing, such as grants and other funding sources, to all who inquire. County staff is also available to make site visits to assist residents.
370 Flood Insurance Promotion – Marin County receives credit for advising people about flood insurance.
410 Floodplain Mapping – Marin County receives credit for mapping special hazards such as tsunamis.
420 Open Space Preservation – Marin County receives credit for preserving open space, preserving the natural functions of open space, creating incentives for preserving open space and for maintaining low density zoning regulations.
430 Higher Regulatory Standards – Marin County receives credit for many of the elements under this Activity such as freeboard, foundation protection, providing local drainage protection, and administering floodplain management regulations. The County also receives credit for 778
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creating, adhering, and enforcing a robust building code. The County also enforced the floodplain management provisions of our zoning, subdivision and building code ordinances. 440 Flood Data Maintenance – Marin County receives credit for maintaining digital Flood Rate Insurance Maps (FIRM). Electronic availability improves public access. Maintaining copies of previous version of the FIRMs provides a significant research tool and valuable service to the residents of Marin County.
450 Stormwater Management – Marin County receives credit for maintaining a Storm Water Management system via healthy erosion and sediment control requirements and water quality regulations. The County regulates development on a case-by-case basis to ensure that runoff is treated before it leaves the site. The County also ensures that stormwater runoff from a site will not exceed the pre-development runoff. The County promotes the use of onsite bio-retention areas or other treatment facilities have been provided to mitigate runoff and water quality. The County enforces regulations to minimize erosion from land disturbance due to construction. 502 Repetitive Loss – Marin County is a Category C community with greater than 50 repetitive Loss properties. The repetitive loss areas are mapped and can be viewed by the public on MarinMap.org. A notice is mailed to each property in the repetitive loss area to advise them of flood prevention measures, insurance requirements and availability, and available financial assistance.
510 Floodplain Management – Marin County receives credit for both its Floodplain Management Plan and its Repetitive Loss Area Analysis. The County has adopted the Marin County MultiJurisdictional Local Hazard Mitigation Plan and produces an annual progress report. Marin County participates in FEMA’s Home Elevation Program which is actively raising homes in the Special Flood Hazard Area.
520 Acquisition and Relocation – Marin County receives some credit for removing homes that have been demolished from the Special Flood Hazard Area. 530 Flood Protection – Marin County receives credit for elevating structures in the Special Flood Hazard Area above the Base Flood Elevation. Staff also provide information on other flood protection techniques such as barriers, wet floodproofing and dry floodproofing. Marin County participates in FEMA’s Home Elevation Program which is actively raising homes in the Special Flood Hazard Area.
540 Drainage Systems Maintenance – Marin County receives credit for removing debris from natural drainage channels and maintaining an active and ongoing maintenance program of problem site area. Marin County also has strong stream dumping regulations which includes outreach to the public.
610 Flood Warning and Response - Marin County receives credit for all of the Elements in the Flood Warning and Response Activity. These Elements include our flood threat recognitions system that identifies an impending flood, our emergency warning dissemination system that warns the public of impending flood, our flood response plan and operations, and coordination with critical facility operators. Marin County is also a registered Storm Ready Community and a Tsunami Ready Community. Marin County receives credit for annual outreach advising 779
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residents of flood warning and safety precautions. The County organizes and participates in an annual flood exercise with the purpose of being prepared for an actual activation of the operations. Following an exercise, the County produces an After Action Report which includes lessons learned as a method to document and improve our flood warning and response procedures.
630 Dams: Credit is provided for a State Dam Safety Program.
Table 4.7: Participation in the National Flood Insurance Program (NFIP) NFIP Topic Source of Information Comments
Insurance Summary
How many NFIP policies
are in the community?
What is the total premium
and coverage?
State NFIP Coordinator or
FEMA NFIP Specialist
As 10/2/23 there are 1327 policies in
force. Total premiums $1,734,601.
Coverage is $406,7104,000.
How many claims have
been paid in the
community? What is the
total amount of paid
claims? How many of the
claims were for
substantial damage?
FEMA NFIP or Insurance
Specialist
As of 10/2/23 the total number of claims
was 773. Total amount of paid claims is
$10,173,472.49.
Since 1978, there have been 51
substantial damage claims.
How many structures are
exposed to flood risk
within the community?
*“flood risk” is defined as
the 1% annual chance flood
(100-year flood. Numbers
are from overlay of FEMA
SFHA and building stock
data.
Community Floodplain
Administrator (FPA)
There are 4536 buildings in the SFHA in
the unincorporated County
Describe any areas of
flood risk with limited
NFIP policy coverage
Community FPA and
FEMA Insurance
Specialist
None
Staff Resources
Is the Community
Floodplain Administrator
or NFIP Coordinator
certified?
Community FPA No
Is floodplain management
an auxiliary function?
Community FPA Yes
Provide an explanation of
NFIP administration
services (e.g., permit
review, GIS, education or
outreach, inspections,
engineering capability)
Community FPA Permits are reviewed for FEMA regulation
and compliance. GIS is used to ascertain
if property is in a flood zone. A final
inspection is performed to ensure
compliance. An annual outreach is
mailed to all properties in SFHA.
What are the barriers to
running an effective NFIP
program in the
community, if any?
Community FPA There are no barriers to running an
effective NFIP program.
780
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Table 4.7: Participation in the National Flood Insurance Program (NFIP) NFIP Topic Source of Information Comments
Compliance History
Is the community in good
standing with the NFIP?
State NFIP Coordinator,
FEMA NFIP Specialist,
community records
yes
Are there any outstanding
compliance issues (i.e.,
current violations)?
no
When was the most recent
Community Assistance
Visit (CAV) or Community
Assistance Contact
(CAC)?
9/15/20
Is a CAV or CAC
scheduled or needed?
The next scheduled CAV will be October
19, 2023
Regulation
When did the community
enter the NFIP?
Community Status Book
http://www.fema.gov/
national-flood-insuranceprogram/national-floodinsurance-programcommunity-status-book March 1, 1984
Are the FIRMs digital or
paper?
Community FPA Marin County has both digital and paper
FIRMS
Do floodplain
development regulations
meet or exceed FEMA or
State minimum
requirements? If so, in
what ways?
Community FPA Marin County regulations meet and
exceed FEMA requirements in the
following: development limitations, higher
regulatory standards for freeboard,
foundation protection, and building codes.
Marin has adopted and enforces
international building Codes.
Provide an explanation of
the permitting process.
Community FPA,
State, FEMA NFIP
Flood Insurance
Manual
http://www.fema.gov/
flood-insurancemanual
Community FPA,
FEMA CRS
Coordinator, ISO
representative
CRS manual http://
www.fema.gov/library/
viewRecord.do?id=2434
Permit applications are received,
reviewed, and approved by professional
staff. Inspections are required at
foundation, close-in and at final. All
projects that will be constructed in the
SFHA will be subject to the provisions of
Marin County Code 24.04 Development
Code and 23.09 Floodplain Management
Code. The finished floor elevation of any
substantial remodel in the SFHA must be
at least 1 foot above the BFE.
Community Rating System (CRS)
Does the community
participate in CRS?
Community FPA, State,
FEMA NFIP
yes
What is the community’s
CRS Class Ranking?
Flood Insurance Manual
http://www.fema.gov/
flood-insurance-manual
Class 6
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Table 4.7: Participation in the National Flood Insurance Program (NFIP) NFIP Topic Source of Information Comments
What categories and
activities provide CRS
points and how can the
class be improved?
Marin receives credit in Series 310, 320,
330, 340, 350, 360, 370, 410, 420, 430,
440, 450, 510, 520. 530, 540, and 610.
Marin County could improve its class
ranking by doing more work in Activities
420, 430, 450, 520, and 630
Does the plan include
CRS planning
requirements
Community FPA,
FEMA CRS
Coordinator, ISO
representative
CRS manual http://
www.fema.gov/library/
viewRecord.do?id=2434
yes
Table 4.7: Participation in the National Flood Insurance Program (NFIP) Source: FEMA, Marin County
NFIP Insurance Coverage Details
Unincorporated Marin County joined the NFIP on March 1, 1982. NFIP insurance data provided by FEMA indicates that as of June 22, 2023, there were 1462 policies in force in the unincorporated Marin County with $1,994,164 in premiums, resulting in $452,421,500 of insurance in force.
There have been 889 closed paid losses totaling $10,360,625. Fifty-one (51) of the claims were considered substantial damage losses.
Of these losses, 572 parcels were in A or V zones, and 317 were in B, C, or X zones. Of the 889 claims, 736 were associated with pre-FIRM structures and 33 with post-FIRM structures.
As of October 19, 2023, there were ninety-three (93) repetitive loss structures in the unincorporated County. Five (5) were in X zones, one (1) was in an A 0.2% zones, one (1) was in an AH zone, three(3) were in AO zones , four (4) were in A zones, fifty-four (54) were in AE zones, fifteen (15) were in AE Floodway zones, and ten (10) were in VE zones. These repetitive loss structures account for $5,090,322 of the total losses in unincorporated Marin County. There were 11 severe repetitive loss properties in unincorporated Marin County totaling $1,152,259.
Repetitive Loss Structures
Repetitive Loss Residential Structures: 84
Repetitive Loss Non-Residential Structures: 9
Severe Repetitive Loss Residential Structures: 6
Severe Repetitive Loss Non-Residential Structures: 3
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4.4.1 SUBSTANTIALLY IMPROVED OR SUBSTANTIALLY DAMAGED PROPERTIES The NFIP includes a requirement that new buildings and substantially improved buildings be constructed in ways that minimize or prevent damage during a flood. This requirement grew out of the recognition that there were large numbers of buildings already located in flood prone areas that would continue to be subject to damage.
The purpose of the substantially improved (SI) or substantially damaged (SD) requirements is to protect the property owner’s investment and safety, and, over time, to reduce the total number of buildings that are exposed to flood damage, thus reducing the burden on taxpayers through the payment of disaster assistance. The SI/SD requirements are triggered when the local official determines that the cost of repairing or improving a building in an SFHA equals or exceeds 50 percent of the building’s market value (excluding land value).
The Marin County Code 23.09 addresses Floodplain Management standards of construction.
The Marin County Construction Certificate Management Procedures, updated May 2023, describes of how the County implements the substantial improvement/substantial damage provisions of their floodplain management regulations.
The Department of Public Works, Land Development Division is responsible for the review, approval and inspection of all land development issues within the County of Marin including FEMA related administrative documents. Review, approval, and inspections of the structure associated with permits are conducted by both the Land Development Division of Public Works and the Building and Safety Division of the Community Development Department.
The following explains the management procedures for review of Elevation Certificates and all other required floodplain-related construction certificates including, but not limited to, Floodproofing Certificates, V Zone design certificates, and engineered flood opening certificates. These procedures outline the types of certificates required, the collection and review of all certificates, how corrections should be made, where the certificates are stored/archived, and how we make these certificates available to the public. (a) TYPES OF CERTIFICATES REQUIRED
When any new construction, substantial improvement or repair for a substantially damaged building is conducted in the Special Flood Hazard Area (SFHA) the Land Development Division of Public Works shall require an Elevation Certificate and any other floodplain-related certificates that are appropriate such as Floodproofing Certificate for Non-Residential Structures, V Zone design certificate, and certification of engineered flood openings for the development.
(a) & (b) WHEN CERTIFICATES ARE REQUIRED
The applicant shall submit an Elevation Certificate marked “construction drawings” with the building permit application. This Elevation Certificate shall be used to determine that the proposed design is in compliance with the Marin County Code 23.09. After the foundation is built and the elevation of the lowest floor is determined, another Elevation Certificate shall be submitted that is marked “building under construction.” This will document the elevation of surrounding grades and the lowest floor to ensure they comply with the approved plans before further construction is allowed. Once construction on the building is finished and all adjacent grading is finalized, a complete and correct “finished-construction” Elevation Certificate must be submitted by the applicant to show the “as-built” characteristics of the building. A “finished783 2023 Marin County Operational Area
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construction” Elevation Certificate must be received, reviewed, and corrected (if necessary) before a final inspection can be scheduled. At this point, all other required certificates must also be submitted and reviewed.
Standard Operating Procedure: A final Elevation Certificate is required as a condition to be completed before the final inspection of the building permit. Prior to issuance a hold is placed on the permit pending the submittal of the Elevation Certificate to the Department of Public Works (DPW).
As part of the County’s efforts to comply with NFIP, Marin County and the Marin OA Hazard Mitigation Working Group will annually review and make updates and revisions to these regulations as necessary to ensure they are most effective at minimizing the threat 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 action. The County will also continue to incorporate any changes to the locations and designations of mapped floodplains into future planning documents, including future updates to this Plan.
The County will also explore opportunities to enforce or enhance County ordinances, building code, and other regulatory actions to address substantial improvements/substantial damage properties. Marin County will consider developing a Substantial Damage Management Plan. 784
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4.5 MITIGATION GOALS
The information developed from the risk assessment was used as the primary basis for developing mitigation goals and objectives. Mitigation goals are defined as general guidelines explaining what each jurisdiction wants to achieve in terms of hazard and loss prevention.
Hazard Risk Prioritization
Mitigation Goals & Objectives
Mitigation Project Identification
Mitigation Project Implementation
Goal statements are typically long-range, policy-oriented statements representing jurisdictionwide visions. Objectives are statements that detail how each jurisdiction’s goals will be achieved, and typically define strategies or implementation steps to attain identified goals. Other important inputs to the development of jurisdiction-level goals and objectives include performing reviews of existing local plans, policy documents, and regulations for consistency and complementary goals, as well as soliciting input from the public.
The following represents overarching strategic goals associated with the identification and eventual implementation of appropriate and meaningful hazard mitigation efforts in relation to prioritized hazards and threats confronting Marin County. These goals form the basis for specific supporting process objectives and are shown from the highest priority, at the top of the list, to those of lesser importance.
The establishment of hazard mitigation goals represents both individual and collective strategies that have been mutually agreed upon by the Steering Committee and have changed with the 2023 MJHMP update. Objectives were added to Goals 2 and 5. Eventually, these goals have been adopted by Marin County and its participating jurisdictions as the guiding policy behind local hazard mitigation efforts, in conjunction with other associated principles.
Goals were defined for the purpose of this mitigation plan as broad-based public policy statements that:
• Represent basic desires of the community;
• Encompass all aspects of community, public and private; • Are nonspecific, in that they refer to the quality (not the quantity) of the outcome; • Are future-oriented, in that they are achievable in the future; and • A time-independent, in that they are not scheduled events.
Goals are stated without regard to implementation. Implementation cost, schedule, and means are not considered. Goals are defined before considering how to accomplish them so that they 44 CFR Requirement §201.6(c)(3)(i) [The hazard mi�ga�on strategy shall include a] descrip�on of mi�ga�on goals to reduce or avoid long‐term vulnerabili�es to the iden�fied hazards. 785
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are not dependent on the means of achievement. Goal statements form the basis for objectives and actions that will be used as means to achieve the goals. Objectives define strategies to attain the goals and are more specific and measurable.
Goal 1: Minimize risk and vulnerability of the community to the impacts of natural hazards and protect lives and reduce damages and losses to property, economy, and environment in Marin County.
• Minimize economic and resource impacts and promote long-term viability and sustainability of resources throughout Marin County.
• Minimize impact to both existing and future development. • Provide protection for public health.
• Prevent and reduce wildfire risk and related losses.
Goal 2: Provide protection for critical facilities, infrastructure, utilities, and services from hazard impacts.
• Incorporate defensible space and reduce hazard vulnerability. • Develop redundancies in utilities and services.
• Enhance resilience through enhanced construction.
Goal 3: Improve public awareness, education, and preparedness for hazards that threaten our communities.
• Enhance public outreach and participation in the Alert Marin Emergency Notification System.
• Enhance public outreach, education, and preparedness program to include all hazards of concern.
• Increase public knowledge about the risk and vulnerability to identified hazards and their recommended responses to disaster events, including evacuation and sheltering options.
• Provide planning and coordination for "At-Risk" populations. • Provide planning and coordination for companion animals, livestock, and other animal populations.
• Increase community awareness and participation in hazard mitigation projects and activities.
Goal 4: Increase communities' capabilities to be prepared for, respond to, and recover from a disaster event.
• Improve interagency (local, state, federal) emergency coordination, planning, training, and communication to ensure effective community preparedness, response and recovery.
• Enhance collaboration and coordination of disaster-related plans, exercises, and training with local, state, and federal agencies, neighboring communities, private partners, and volunteers.
• Enhance the use of shared resources/Develop a strong mutual aid support system. • Create and maintain a fully functional, interoperable radio and communication system with all regional public safety partners.
Goal 5: Maintain FEMA Eligibility/Position the communities for grant funding. • Review hazard events and ongoing hazard mitigation projects annually. 786
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• Assess the need to pursue or adjust hazard mitigation projects after significant hazard events.
Goal 6: Reduce exposure to High Hazard Dams that pose an unacceptable risk to the public. • Improve alert and warning systems to provide residents downstream of a High Hazard Dam to receive timely warning to evacuation when threatened by potential or imminent dam failure.
• Enhance overall community preparedness to respond and evacuate a potential or imminent dam failure.
• Increase public awareness of the risk posed by High Hazard Dams and the potential for relocation of housing outside a possible inundation zone. • Prioritize High Hazard Dam Mitigation projects and programs.
4.6 HAZARD MITIGATION ACTIONS
The 2023 Marin County OA MJHMP was revised to reflect progress in local mitigation efforts.
Mitigation projects were selected for each hazard and for Marin County and its participating jurisdictions based off the hazard risk assessment. The projects are supported by the mitigation goals and objectives, and are ranked using the following criteria; approximate cost, timeframe of completion, whether the project requires Board of Supervisors regulatory action, and an assumption as to whether or not the project would be subject to CEQA or NEPA requirements.
Funding sources are identified for all projects. All projects consider new, future, and existing development. Project worksheets are used by the Planning Team and Steering Committee to describe criteria for each project.
4.6.1 PROGRESS IN LOCAL MITIGATION EFFORTS
This plan has been created as a “living” document with input from the population and professionals within Marin County and its participating jurisdictions. Based on the planning meetings and the progress monitored by the steering committee members, several mitigation 44 CFR Requirement §201.6(c)(3)(ii) [The hazard mi�ga�on strategy shall include a] sec�on that iden�fies and analyzes a comprehensive range of specific mi�ga�on ac�ons and projects being considered to reduce the effects of each hazard, with par�cular emphasis on new and exis�ng buildings and infrastructure. All plans approved by FEMA a�er October 1, 2008, must also address the jurisdic�on’s par�cipa�on in the NFIP, and con�nued compliance with NFIP requirements, as appropriate.
§201.6(c)(3)(iii) [The hazard mi�ga�on strategy shall include an] ac�on plan, describing how the ac�on iden�fied in paragraph (c)(3)(ii) of this sec�on will be priori�zed, implemented, and administered by the local jurisdic�on. Priori�za�on shall include a special emphasis on the extent to which benefits are maximized according to a cost benefit review of the proposed projects and their associated costs.
§201.6(c)(3)(iv) For mul�‐jurisdic�onal plans, there must be iden�fiable ac�on items specific to the jurisdic�on reques�ng FEMA approval or credit of the plan. 787
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actions were accomplished since the last planning cycle. Table 4.8 provides a brief description of the progress made in the local mitigation efforts and the plan for those mitigation actions that were not completed or are ongoing.
4.6.2 STATUS OF PREVIOUS MITIGATION ACTIONS
Table 4.8 summarizes the actions that were recommended in the previous version of the hazard mitigation plan and their implementation status at the time this update was prepared.
Table 4.8: Status of Previous Hazard Mitigation Actions Action Number / Name Completed Ongoing Not
Started
Still
Relevant
Included in
Updated
Action
Plan
(1) Seismic Retrofit of County-owned buildings not
current to code. West Marin Service Center, Point
Reyes Station
X N
(2) Seismic Retrofit of County-owned buildings not
current to code. Civic Center Roof Replacement X N
(3) Seismic Retrofit of County-owned buildings not
current to code. Tomales Fire Station- Replacement X N
(4) Seismic Retrofit of County-owned buildings not
current to code. 120 N. Redwood- Seismic
Assessment
X Y
(5) Seismic Retrofit of County-owned buildings not
current to code. Marin Center- Seismic Assessment
of the Veteran's Memorial Auditorium & Exhibit Hall
X Y
52 Follow all four phases of FEMA's How-to-Guide:
"Integrating Historic Property and Cultural Resource
Considerations Hazard Mitigation Planning"
X N
Acquire electric bikes and safety equipment for
official use during major disasters. X N
Arroyo Corte Madera del Presidio Riverine Flood
Risk Reduction project: Assist with reducing the
frequency and severity of flooding. Study completed
on 03/2022 with the best option to move forward with
a restoration project.
X N
Assess bulkheads surrounding Tomales Bay X Y
Azalea Ave Bridge Replacement project will replace
the original Azalea Bridge, to decrease flood
hazards.
Town of
Fairfax is
project
lead.
Bothin Marsh Restoration project. Thin-lift
placement of sediment from Coyote Creek into
Bothin Marsh.
X Y
Improve City of Novato Drainage Improvement
informed by study currently in process. Goal to
bypass high flows, increase storage, develop flood
barriers, daylighting drainages, and install pump
stations and/ or tide gates.
X Y
Conduct a comprehensive finished floor-elevation
inventory. Project to understand a Floor Elevation
Survey to determine the floor elevation of a
structure.
X N
Consider sea level rise adaptation from
Collaboration: Sea-level Marin Adaption Response
Team (C-SMART).
X Y
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Table 4.8: Status of Previous Hazard Mitigation Actions Action Number / Name Completed Ongoing Not
Started
Still
Relevant
Included in
Updated
Action
Plan
Continue supporting the Sonoma County Water
Agency led Advanced Quantitative Precipitation
Information effort.
X Y
Corrillo Drive Pipe Rehabilitation was completed by
San Rafael in cooperation with flood zone 6. X N
Corte Madera Creek Flood Risk Management Project
will help to reduce the frequency of flooding by
enhancing natural stream functions. An HMGP
application for components in the channel that
reduce flood risk was submitted August 4, 2023
X Y
Cove Pump Station Improvements were completed
in 2022 and will assist with the updates to the pump. X N Coyote Creek Levee Improvements - a levee study
was completed, and a portion of the levee system
has a project underway for seepage mitigation. It is
in the design phase.
X Y
Crest Marin, Cardinal, and Shoreline Pump Station
Upgrades. A condition assessment for Crest Marin is
nearly complete.
X Y
Deer Island Basin Project to setback levees, restore
tidal wetlands, and increase tidal prism to reduce
sedimentation and flood risk. CEQA complete,
design underway.
X Y
Develop Renters and Homeowners Guides to Flood
Preparedness project outlining safety directives for
homeowners and renters during a potential flood
hazard.
X Y Y
Easkoot Creek Flood Flow Bypass Project. National
Park Service is working with FHWA and the Flood
District to identify and plan a potential overflow
channel from Easkoot Creek to the Ocean.
X Y
East Creek Outfall Modifications project is a
pavement rehabilitation project and potentially
include tide gates to reduce sunny day flooding of
Tiburon Blvd.
X Y
Encourage property owners in SFHAs to purchase
flood insurance. X Y
Establish additional local funding mechanisms for
increased flood and fire mitigation. X Y
Estancia Ditch and Pump Station improvement
project. All pump stations in Santa Ventia were
upgraded to the Trimble Unity systems. Additional
upgrades needed.
X Y
Flood Preparedness Pilot Program identifies
resources for flood preparedness on county website. X Y Gallinas Creek Geomorphic Dredge, currently in
design phase for the placement of 100,000 cubic
yards of dredge sediment
X Y
Initiate Community Plans for Adapting to Coastal
Hazards X Y
Karen Way Ditch Improvements is currently on hold X Y
Las Gallinas Levee Evaluation provides geotechnical
engineering service for the elevation and
assessment consistent with the Corps of Engineers
(USACE) Publication Number EM 1110-2-1913.
X N
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Table 4.8: Status of Previous Hazard Mitigation Actions Action Number / Name Completed Ongoing Not
Started
Still
Relevant
Included in
Updated
Action
Plan
Levee Setback and Upgrade Project. Initiation of this
project depends on completion of a land exchange
through State Lands Commission. County is working
on surveying needed to support that exchange.
X Y
Lower Corte Madera Creek Improvements: Levee
evaluation completed in 2020 under a DWR grant
and a geomorphic dredge assessment in process to
be completed in 2023
Y
Lower Ryan Creek Pump Station Study and
Upgrades is currently on hold Y
Madrone Ave Bridge Replacement project will
reduce impacts from floods.
Town of
San
Anselmo is
project
lead.
Manzanita Modifications Project. Caltrans is working
on a project initiation document for December 2023
for sea level rise adaptation at the US 101/SR 1
between Manzanita and Marin City. County is
supporting this work through hydraulic studies.
X Y
Marin City Drainage Improvements Project, currently
in the planning phase of project. X Y
Marin County Structure Elevation Program provides
federal assistance to homeowners with costeffective projects. FEMA funding approved; 7 permits are being reviewed.
X Y
Marin County Watershed Program provides a
framework to integrate flood protection and
environmental restoration with public and private
partners to protect and enhance Marin’s watersheds.
X N
McInnis Park Wetland Restoration Project proposes
to restore subtidal and intertidal habitat at an 180-
acre are of diked wetlands.
X Y
Meadow Drive Interceptor and Ditch Upgrades.
Interim upgrades were made by adding an in-line
check valve to prevent tides from flooding Meadow
Dr. No funding (or local match) currently available
for full conceptual upgrades to proceed to design.
X Y
Mill Valley Comprehensive Flood Control & Drainage
Master Plan X N
Nokomis Ave Bridge Replacement project will assist
with the replacement of the Nokomis Ave Bridge,
with the hopes of reducing flood hazards.
Town of
San
Anselmo is
project
lead.
Novato Levee Study, completed in 2020 under a
DWR grant. X N
Pacheco Pond Project is currently on hold X Y
Protect and restore natural buffers. Two funded and
completed nature-based studies explored the
feasibility of these projects and follow up work is
now happening through the Stinson ARC project and
through pursuit of other grant opportunities.
X Y
Pump Station No. 1 Upgrade is currently on hold. X Y
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Table 4.8: Status of Previous Hazard Mitigation Actions Action Number / Name Completed Ongoing Not
Started
Still
Relevant
Included in
Updated
Action
Plan
Pump Station No. 2 Upgrade, and interconnection to
Pump Station No. 1 is currently on hold. X Y
Pump Station No. 5 Upgrade on hold. X Y
Richardson Bay Shoreline Protection work is to be
integrated into future sea level rise adaptation
planning.
X Y Y
Ross Valley 10 Year Work Plan described technical
rationale for a suite of on-the-ground flood reduction
measures, spread watershed-wide, that work
together as a system to reduce flooding and seek to
restore the ecological health and function of Corte
Madera Creek and its tributaries
X N
Rush Creek Drainage Improvements is currently on
hold X Y
San Anselmo Flood Risk Reduction Project.
Construction of flood detention basin on Fairfax
Creek was substantially completed and the basin
operational in November 2022. The outfall pipe slide
gate can be operated manually and pending
installation of electrical paneling March 2023 for
electrical control operation. The project to remove
the building bridge in downtown San Anselmo is in
the final planning phase
X Y
Santa Venetia and Rafael Meadows Street Drain
Upgrades. Coordinating with County Engineering to
include drainage upgrades with road rehabilitation
projects. Labrea Way, vulnerable to recurrent
stormwater ponding, is currently in design.
X Y
Santa Venetia Pump Station No. 4 Upgrades on hold X Y
Santa Venetia Floodwall Project (Formerly the Santa
Veneita Timber-Reinforced Berm Improvement
Project)
X Y
Seismic Retrofit of County-owned buildings not
current to code. X Y
Seismic upgrades (bolting and anchoring pumps
and roof) to the Cove Pump Station building in
Tiburon.
X Y
Simmons Slough Flood Risk Reduction Project X N
Strawberry Levee Improvements will be incorporated
into sea level rise planning X Y Y
The Sycamore Ave Bridge Replacement project will
reduce the impact of flooding.
Town of
San
Anselmo is
project
lead and
federally
funded.
Tiburon Street Drainage Improvements Plan
identifies support to the town of Tiburon's storm
drainage, providing upgrades to the Cove
Stormwater pump station.
X Y
The upgrade Farmers, Cheda, and Lynwood pump
stations is currently on hold. X Y
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Table 4.8: Status of Previous Hazard Mitigation Actions Source: Marin County
4.6.3 NEW MITIGATION ACTIONS
Based on the hazard profiles, threat assessment, capabilities assessment, community survey results, discussions among the Hazard Mitigation Planning Team members, and existing best practices, a set of potential mitigation actions was developed and then evaluated based on the following criteria:
• FEMA requires local governments to evaluate the monetary and non-monetary costs and benefits of potential mitigation actions. Although local governments are not required to assign specific dollar values to each action, they should identify the general size of costs and benefits.
• The Hazard Mitigation Planning Team may elect to include measures with a high cost or low benefits, but such measures should be clearly beneficial to the community and an appropriate use of local resources.
In addition, FEMA directs local governments to consider the following questions as part of the financial analysis:
• 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?
• What impacts of the hazard will the action reduce or avoid? • What benefits will the action provide to the community? The Hazard Mitigation Planning Team also chose to review and revise the potential hazard mitigation actions with consideration for climate impact and social vulnerability. Projects and programs were assessed with consideration of these variables.
Prioritization
As part of the mitigation actions development and review, the Hazard Mitigation Planning Team also prioritized the actions. The prioritization efforts looked at the risks and threats from each hazard; lifesaving, life safety, property protection and lastly environmental protection; financial costs and benefits; technical feasibility; consideration for climate impact, and social vulnerability, and community values. Hazard Mitigation Planning Team members were asked to identify their priority actions using the following criteria.
Table 4.8: Status of Previous Hazard Mitigation Actions Action Number / Name Completed Ongoing Not
Started
Still
Relevant
Included in
Updated
Action
Plan
The West Creek Flood Wall Alternative Restoration
Project is currently on hold. X Y
The Winship Bridge Replacement project will reduce
the impact of flooding.
Town of
Ross is
the project
lead and
federally
funded.
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Implementation priority ratings were assigned as follows:
• High Priority - An action that meets multiple objectives, is linked to a high risk hazard, has benefits that exceed costs, and has a potential source of funding. Action can begin within the short term (1 to 5 years).
• Medium Priority - An action that meets multiple objectives, is linked to a high or medium risk hazard, has benefits that exceed costs, and is eligible for funding though no funding has yet been secured for it. Action can begin within the short term (1 to 5 years) once funding is secured.
• Low Priority - An action that will mitigate the risk of a hazard, has benefits that do not exceed the costs or are difficult to quantify, has no secured source of funding, and is not eligible for any known grant funding. Action can be completed in the long term (1 to 10 years). Low-priority actions may be eligible for grant funding from programs that have not yet been identified.
Table 4.9 lists the Current Hazard Mitigation Actions for Marin County. 793
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Table 4.9: Marin County Current Hazard Mitigation Actions No. Mitigation Action
Hazards
Mitigated/
Goals
Met
Jurisdiction/
Responsible
Agency
New,
Existing,
Completed,
Removed
Estimated Cost
and Potential
Funding Source
Timeline/
Priority Comments/Progress
MC-1
Develop a Vulnerable Communities
Index specific to Marin County,
aggregating economic, gender,
age, linguistic, ethnic, and racial
characteristics; geographic
locations; hazard impact; and
adaptive capacity.
All Hazards
1, 2, 3, 4, 5,
6 County of
Marin - CDA
New TBD Cost
General
Funds/Grants
HMPG, BRIC, CDC,
CDPH Public Health
Emergency
Preparedness
2-5 years
Medium Safety Element Action
CA Dept. of Public
Health - Community
Assessment for Public
Health Emergency
Response (CASPER)
MC-2
Develop a climate change
preparedness outreach program for
higher risk populations.
All Hazards
1, 3
County of
Marin – CDA,
OEM/Fire, Fire
Agencies
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Medium Safety Element Action
MC-3
Provide grants for alternative
housing to community members at
risk of climate change impacts.
All Hazards
1, 3
County of
Marin – CDA,
OEM/Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
5+ years
Low Safety Element Action
MC-4
Mitigate by planning in advance for
climate change impacts and
incorporating lessons learned in
neighboring counties.
All Hazards
All goals
County of
Marin –
OEM/Fire,
CDA, DPW
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Medium Safety Element Action
MC-5
Develop a Property Rating System. All Hazards
1 County of
Marin - CDA
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Medium Safety Element Action
MC-6
Develop Resilience Hubs. All Hazards
1, 2, 4
County of
Marin – CDA
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Medium Safety Element Action
794
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
433
Table 4.9: Marin County Current Hazard Mitigation Actions No. Mitigation Action
Hazards
Mitigated/
Goals
Met
Jurisdiction/
Responsible
Agency
New,
Existing,
Completed,
Removed
Estimated Cost
and Potential
Funding Source
Timeline/
Priority Comments/Progress
MC-7
Focus improvements on the
transportation network for risk
reduction, especially informed by
new and emerging climate risk.
All Hazards
1, 2, 5
County of
Marin – CDA
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Medium
MC-8
Conduct study to identify natural
methods to limit coastal erosion
Land
Subsidence
1, 4, 5
County of
Marin –
OEM/Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Low
MC-9
Conduct research on best natural
methods to mitigate erosion on
highways and roads and implement
planning and strategy stage.
Land
Subsidence
1, 4, 5
County of
Marin –
OEM/Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC, BRIC
technical assistance
2-5 years
Low
MC-10
Conduct research on best natural
methods to mitigate erosion in and
around rivers and streams and
implement planning and strategy
stage.
Land
Subsidence
1, 2, 4, 5
County of
Marin –
OEM/Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC, BRIC
technical assistance
2-5 years
Low
MC-11
Addition of vegetation in soil eroded
areas.
Land
Subsidence
1, 2, 5
County of
Marin –
OEM/Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Low
MC-12
Increase conventional storage that
is filled during high-flow periods
Drought,
Flooding
1, 5
County of
Marin –
OEM/Fire
New TBD Cost
General
Funds/Grants/FMA,
DWR, HMGP, BRIC
5+ Years
Low
795
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
434
Table 4.9: Marin County Current Hazard Mitigation Actions No. Mitigation Action
Hazards
Mitigated/
Goals
Met
Jurisdiction/
Responsible
Agency
New,
Existing,
Completed,
Removed
Estimated Cost
and Potential
Funding Source
Timeline/
Priority Comments/Progress
MC-13
Provide multilingual outreach on
mitigation tactics to well-dependent
residents
Drought
1, 3
County of
Marin –
OEM/Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Medium
MC-14
Conduct Outreach and acquire
grants to pass to rural communities
for installing Rainwater Harvesting
systems
Drought
1, 5
County of
Marin –
OEM/Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Medium
MC-15
Identify alternative water supplies
for times of drought; mutual aid
agreements with alternative
suppliers
Drought
1, 5
County of
Marin –
OEM/Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Low
MC-16
Remove non-native plants and trees
from all County and City and Town
facilities, replace with drought
tolerant, native plants
Flooding,
Drought
1, 2, 5
County of
Marin –
OEM/Fire
New TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
2-5 years
Low
MC-17
Turn soil to increase infiltration rate
and pore space to absorb more
water
Flooding,
Drought
1, 5
County of
Marin –
OEM/Fire
New TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
2-5 years
Low
MC-18
Encourage soil turning on private
land
Flooding,
Drought
1, 3, 5
County of
Marin –
OEM/Fire
New TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
2-5 years
Low
796
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
435
Table 4.9: Marin County Current Hazard Mitigation Actions No. Mitigation Action
Hazards
Mitigated/
Goals
Met
Jurisdiction/
Responsible
Agency
New,
Existing,
Completed,
Removed
Estimated Cost
and Potential
Funding Source
Timeline/
Priority Comments/Progress
MC-19
Install new HVAC systems at
schools and critical infrastructure
facilities
Heat
1, 5
County of
Marin –
OEM/Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Medium
MC-20
Implement non-AC solutions to cool
buildings - green roof and naturebased infrastructure systems Heat
1, 5
County of
Marin –
OEM/Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Low
MC-21
Paint roofs with pigments to reduce
heat inside buildings
Heat
1, 5
County of
Marin –
OEM/Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Low
MC-22
Outreach to communities at high
risk of heat impacts
Heat
1, 3, 5
County of
Marin –
OEM/Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Medium
MC-23
Establish policy for cooler homes /
Earthship homes
Heat
1, 4, 5
County of
Marin –
OEM/Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Low
MC-24
Provide grants for high-risk
residents to improve and acquire
cooling mechanism in home.
Heat
1, 3, 5
County of
Marin –
OEM/Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Medium
797
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
436
Table 4.9: Marin County Current Hazard Mitigation Actions No. Mitigation Action
Hazards
Mitigated/
Goals
Met
Jurisdiction/
Responsible
Agency
New,
Existing,
Completed,
Removed
Estimated Cost
and Potential
Funding Source
Timeline/
Priority Comments/Progress
MC-25
Provide alternative locations and
equitable response actions for
residents to seek cooler
environments (e.g., movie theaters)
via regional heat response plans
Heat
1, 3, 5
County of
Marin –
OEM/Fire
TBD Cost
General
Funds/Grants
HMPG, BRIC
0-2 years
Medium
MC-26
Establish additional and expand
functionality of heating, cooling
centers and resiliency hubs.
Heat
1, 3, 5
County of
Marin –
OEM/Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Low
MC-27
Replace concrete sidewalks with
DG
Heat,
Flooding
1, 2, 5
County of
Marin –
OEM/Fire
New TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
2-5 years
Low
MC-28
Implement green streets initiatives
in identified areas
Heat,
Flooding
1, 5
County of
Marin –
OEM/Fire
New TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
2-5 years
Low
MC-29
Install green roofs on public
buildings supported by non-potable
water
Heat,
Flooding
1, 2, 5
County of
Marin –
OEM/Fire
New TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
2-5 years
Low
MC-30
Conduct a whole county study on
what areas could benefit from more
shaded areas; a green streets
program.
Heat,
Flooding
1, 2, 5
County of
Marin –
OEM/Fire
New TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
2-5 years
Low
798
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
437
Table 4.9: Marin County Current Hazard Mitigation Actions No. Mitigation Action
Hazards
Mitigated/
Goals
Met
Jurisdiction/
Responsible
Agency
New,
Existing,
Completed,
Removed
Estimated Cost
and Potential
Funding Source
Timeline/
Priority Comments/Progress
MC-31
Conduct study on how much
concrete can be removed
Heat,
Flooding
1, 2, 5
County of
Marin –
OEM/Fire
New TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
2-5 years
Low
MC-32
Implement countywide flood
monitoring system to inform
mitigation future projects
Flooding
1, 2, 5
County of
Marin –
OEM/Fire
New TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
2-5 years
Medium
MC-33
Conduct research on widening
storm channels and aged
infrastructure which has not been
climate change adapted and in need
of enhancements
Flooding
1, 2, 5
County of
Marin –
OEM/Fire
New TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC,
BRIC technical
assistance
2-5 years
Low
MC-34
Widen storm channels in highdensity areas and urban settingsFlooding 1, 2, 5
County of
Marin –
OEM/Fire
New TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
5-10 years
Low
MC-35
Develop policy to remove concrete
parking lots
Flooding
1, 4, 5
County of
Marin –
OEM/Fire
New TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
2-5 years
Low
MC-36
Expand culverts in areas classified
as 100- or 500-year flood plain
Flooding
1, 2, 5
County of
Marin –
OEM/Fire
New TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
5-10 years
Low
799
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
438
Table 4.9: Marin County Current Hazard Mitigation Actions No. Mitigation Action
Hazards
Mitigated/
Goals
Met
Jurisdiction/
Responsible
Agency
New,
Existing,
Completed,
Removed
Estimated Cost
and Potential
Funding Source
Timeline/
Priority Comments/Progress
MC-37
Assess County and Town owned
parking lots to implement catch
basins
Flooding
1, 2, 5
County of
Marin –
OEM/Fire,
Cities and
Towns
New TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
2-5 years
Low
MC-38
Design creek restoration projects on
East and West Creek to improve
flood conveyance capacity
Flooding
1, 2, 5
County of
Marin – DPW
New TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
2-5 years
Medium
MC-39
Marin City Stormwater improvement
project to limit standing water and
flooding.
Flooding
1, 2, 5
County of
Marin – DPW
New TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
2-7 years
High
MC-40
Research, design, and construct the
Santa Venetia Floodwall Project
Flooding
1, 5
County of
Marin – DPW
New TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC,
BRIC technical
assistance
5-10 years
Low
MC-41
Novato Bypass improvement project
to reduce flooding
Flooding
1, 5
County of
Marin – DPW
New TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
2-7 years
Low
MC-42
Corte Madera Creek Flood Risk
Management Project Phase 1,
Access Ramp and Granton Park
Pump Station
Flooding
1, 5
County of
Marin – DPW
New $4,104,227.00 bid +
contingency. 50%
reimbursed by DWR
Grant, 50% paid by
FCZ 9.
2-5 years
Low
800
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
439
Table 4.9: Marin County Current Hazard Mitigation Actions No. Mitigation Action
Hazards
Mitigated/
Goals
Met
Jurisdiction/
Responsible
Agency
New,
Existing,
Completed,
Removed
Estimated Cost
and Potential
Funding Source
Timeline/
Priority Comments/Progress
MC-43
Develop Integrated Flood Modeling
System to New Weather Radars
Flooding
1, 5
County of
Marin – DPW
New TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
2-5 years
Low
MC-44
Apply below grade waterproofing
and implement other water-intrusion
mitigation measures to protect
facilities that are experiencing
increased levels of hydrostatic
pressure.
Flooding
1, 2, 5
County of
Marin – DPW
New TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
2-5 years
Low
MC-45
Cardinal Rd Levee Upgrade -
Seepage Mitigation for a segment of
Coyote Creek Levee (~1,000 LF)
Flooding,
Sea Level
Rise
1, 2, 5
County of
Marin – DPW
New TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
2-5 years
Low
MC-46
Conduct sea level rise vulnerability
analysis of County Flood Control
District-owned and operated flood
control assets
Flooding,
Sea Level
Rise
1, 2, 5
County of
Marin – DPW
New TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
2-5 years
Low
MC-47
Harden the North San Pedro Road
Improvement at China Camp to
preserve the transportation corridor
through China Camp State Park.
Preserve the corridor for emergency
evacuations route and future sea
level rise.
Flooding,
Sea Level
Rise
1, 2, 5
County of
Marin – DPW
New TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
2-5 years
Low
MC-48
Construct coarse-grained beach
marsh and shoreline edge
restoration to inhibit marsh and bay
coastal shoreline edge erosion due
to wind-wave erosion and SLR
Sea Level
Rise
1, 5
County of
Marin - DPW
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Low
801
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
440
Table 4.9: Marin County Current Hazard Mitigation Actions No. Mitigation Action
Hazards
Mitigated/
Goals
Met
Jurisdiction/
Responsible
Agency
New,
Existing,
Completed,
Removed
Estimated Cost
and Potential
Funding Source
Timeline/
Priority Comments/Progress
MC-49
Construct Corte Madera Creek
Flood Risk Management Project
Phase 1, Lower COM Restoration
Sea Level
Rise
1, 5
County of
Marin – DPW
New Cost Estimate
$3,000,000. 50%
eligible for
reimbursement by
DWR Grant, 50% to
be covered by FCZ 9
with additional
construction grant
funding being sought.
2-7 years
Medium
100% design, seeking
additional construction
funding
MC-50
Reduce impacts from Sea level rise
and protect natural storm barriers by
researching and restoring Tiscornia
Marsh and other wetlands and
marsh areas
Sea Level
Rise
1, 5
County of
Marin – OEM /
Fire, City of
San Rafael
New TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC,
BRIC technical
assistance
2-10 years
Medium
MC-51
Create offshore wetlands in low
lying areas susceptible to climate
driven sea level rise
Sea Level
Rise
1, 2, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
2-5 years
Low
MC-52
Implement vegetation in coastal
areas to limit sea level rise and
storm surge
Sea Level
Rise
1, 2, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
2-5 years
Low
MC-53
Enhance public awareness of
evolving flood risk hazards due to
sea level rise, both on county's
coast and bay side
Sea Level
Rise
1, 3, 5
County of
Marin – DPW,
OEM
New TBD Cost
General
Funds/Grants
FMA, DWR, HMGP,
BRIC
2-5 years,
ongoing
Medium
802
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
441
Table 4.9: Marin County Current Hazard Mitigation Actions No. Mitigation Action
Hazards
Mitigated/
Goals
Met
Jurisdiction/
Responsible
Agency
New,
Existing,
Completed,
Removed
Estimated Cost
and Potential
Funding Source
Timeline/
Priority Comments/Progress
MC-54
Novato Baylands Resilience
Projects - including, Levee
Improvements, Setback Levee
Construction, Pump Station
Construction and Tidal Restoration
Sea Level
Rise
1, 2, 5
County of
Marin – DPW
New TBD Cost
General
Funds/Grants
FMA, DWR, HMGP,
BRIC
2-10 years
Low
MC-55
Geomorphic dredging of Tidal Flood
Control Channels and Thin-Lift
Marsh Augmentation for SLR
Resiliency
Sea Level
Rise
1, 2, 5
County of
Marin – DPW
New TBD Cost
General
Funds/Grants
FMA, DWR, HMGP,
BRIC
2-7 years
Low
MC-56
Southern Marin Levee
Improvements and New Levee
Construction with Associated
Pumping for Direct Coastal Flooding
Impacts
Sea Level
Rise
1, 2, 5
County of
Marin – DPW
New TBD Cost
General
Funds/Grants
FMA, DWR, HMGP,
BRIC
2-7 years
High
MC-57
Complete designs and implement
wetland restoration project to protect
Bothin Marsh Open Space Preserve
and Bay Trail
Sea Level
Rise
1, 5
County of
Marin – Parks
New $25,000,000
General
Funds/Grants
FMA, DWR, HMGP,
BRIC
15 years
Medium
Preliminary designs
completed
MC-58
Develop designs and implement
wetland resilience improvements
along shoreline of Bolinas Lagoon
Sea Level
Rise
1, 5
County of
Marin – Parks
New $15,000,000
General
Funds/Grants
FMA, DWR, HMGP,
BRIC
15 years
Low
Letter Property and Pine
Gulch Creek
MC-59
Develop designs and implement
McInnis Marsh and Bucks Landing
wetland resilience features
Sea Level
Rise
1, 5
County of
Marin – Parks
New $35,000,000
General
Funds/Grants
FMA, DWR, HMGP,
BRIC
15 years
Low
803
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
442
Table 4.9: Marin County Current Hazard Mitigation Actions No. Mitigation Action
Hazards
Mitigated/
Goals
Met
Jurisdiction/
Responsible
Agency
New,
Existing,
Completed,
Removed
Estimated Cost
and Potential
Funding Source
Timeline/
Priority Comments/Progress
MC-60
Develop plan to prioritize high value
areas of potential wetland
expansion
Sea Level
Rise
1, 5
County of
Marin – Parks
New $500,000
General
Funds/Grants
FMA, DWR, HMGP,
BRIC
3 years
Low
MC-61
Research, Plan, and Construct
Tsunami Evacuation structures near
high-risk areas vulnerable to
tsunami inundation
Tsunami
1, 2, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC, BRIC
technical assistance
2-10 years
Low
MC-62
Enhance public awareness of
mitigation approaches for tsunami,
including on bay side of county
Tsunami
1, 3, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years,
ongoing
Medium
MC-63
Provide incentives to guide
development away from high-risk
areas
Tsunami
1, 2, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Low
MC-64
Plan for tsunami evacuation routes Tsunami
1, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Medium
MC-65
Put signage in place for evacuation
routes
Tsunami
1, 3, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
High
804
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
443
Table 4.9: Marin County Current Hazard Mitigation Actions No. Mitigation Action
Hazards
Mitigated/
Goals
Met
Jurisdiction/
Responsible
Agency
New,
Existing,
Completed,
Removed
Estimated Cost
and Potential
Funding Source
Timeline/
Priority Comments/Progress
MC-66
Research, Analyze, and Harden
schools in tsunami inundation zones
Tsunami
1, 2, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC, BRIC
technical assistance
2-10 years
Medium
MC-67
Harden piers and boat ramps to
withstand tsunami forces
Tsunami
1, 2, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Low
MC-68
Create barriers around public safety
water resources to mitigate tsunami
forces
Tsunami
1, 2, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Medium
MC-69
Harden and lift critical infrastructure
in 1 and 3 feet for sea level rise
areas.
Sea Level
Rise,
Flooding,
Tsunami
1, 2, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
2-10 years
Low
MC-70
Strengthen roads to withstand
natural hazards like fires and water
inundation. Reduce regulatory
impediments to road construction,
widening, and other improvements
by amending relevant sections of
Marin County Code Titles 22, 23,
and 24 to eliminate discretionary
permit requirements and replace
them with ministerial review to
ensure that both public and private
roads comply with codified
engineering standards
Wildfire,
Flooding
1, 2, 4, 5
County of
Marin – CDA,
DPW, Fire
Agencies
New TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
2-10 years
Low
Safety Element Activity
805
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
444
Table 4.9: Marin County Current Hazard Mitigation Actions No. Mitigation Action
Hazards
Mitigated/
Goals
Met
Jurisdiction/
Responsible
Agency
New,
Existing,
Completed,
Removed
Estimated Cost
and Potential
Funding Source
Timeline/
Priority Comments/Progress
MC-71
Review permit processes to ensure
that all applications for new
development comply with fire safety
and building code standards,
including but not limited to ensuring
the provision of adequate water
supply for fire suppression and fire
flow requirements.
Wildfire
1, 4, 5
County of
Marin – CDA,
Fire Agencies
New TBD Cost
General
Funds/Grants
HMPG, BRIC, BRIC
technical assistance
2-5 years
Medium
Safety Element Activity
MC-72
Electric signage for in VHFD and
HFD areas alerting residents on red
flag days
Wildfire
1, 3, 5
County of
Marin – OEM,
HHS
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Low
MC-73
Amend Wildlands Urban Interface
(WUI) Regulations. Work with Marin
Fire agencies to prepare and adopt
WUI regulations for new
development and substantial
remodels to reduce fire hazards.
Track and update standards as the
areas of high and extreme fire
hazard areas are defined.
Wildfire
1, 4, 5
County of
Marin – CDA,
Fire agencies
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Medium
Safety Element Activity
MC-74
Identify Areas with Insufficient
Evacuation Opportunities.
Wildfire
1, 5
County of
Marin – CDA,
Fire Agencies
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Medium
Safety Element Activity
MC-75
Remove hazardous trees and
vegetation, including non-native
species throughout the High and
Very High Fire Danger Areas.
Wildfire
1, 2, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-10 years
Low
806
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
445
Table 4.9: Marin County Current Hazard Mitigation Actions No. Mitigation Action
Hazards
Mitigated/
Goals
Met
Jurisdiction/
Responsible
Agency
New,
Existing,
Completed,
Removed
Estimated Cost
and Potential
Funding Source
Timeline/
Priority Comments/Progress
MC-76
County-wide assessment of
hazardous trees and vegetation
Wildfire
1, 2, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Low
MC-77
Deploy additional AI cameras for fire
ignition and detection
Wildfire
1, 2, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Low
MC-78
Conduct research on impact of
wildfire smoke on southeastern
portion of the county
Wildfire
1, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC, BRIC
technical assistance
2-5 years
Low
MC-79
Create green breaks in county in
VHFD and HFD Areas
Wildfire
1, 2, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Low
MC-80
Expand fuel management by
collaborating with land management
agencies
Wildfire
1, 2, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Low
MC-81
Encourage vegetation modification
at private residences
Wildfire
1, 3, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Medium
807
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
446
Table 4.9: Marin County Current Hazard Mitigation Actions No. Mitigation Action
Hazards
Mitigated/
Goals
Met
Jurisdiction/
Responsible
Agency
New,
Existing,
Completed,
Removed
Estimated Cost
and Potential
Funding Source
Timeline/
Priority Comments/Progress
MC-82
Conduct a county wide fuels study
to understand how different
vegetation would behave when
ignited
Wildfire
1, 2, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Low
MC-83
Conduct a vegetation study in high
and very high fire hazard areas
Wildfire
1, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Low
MC-84
Implement culturally informed
(especially native tribal culture)
wildfire mitigation projects
Wildfire
1, 3, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Medium
MC-85
Encourage fire resistant
construction and landscaping
Wildfire
1, 2, 3, 4, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Medium
MC-86
Exceed codes and standards for fire
resistant construction
Wildfire
1, 2, 3, 4, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
High
MC-87
Harden fire roads to withstand
impacts from natural hazards
Wildfire
1, 2, 3, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Low
808
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
447
Table 4.9: Marin County Current Hazard Mitigation Actions No. Mitigation Action
Hazards
Mitigated/
Goals
Met
Jurisdiction/
Responsible
Agency
New,
Existing,
Completed,
Removed
Estimated Cost
and Potential
Funding Source
Timeline/
Priority Comments/Progress
MC-88
Conduct brush clearance around fire
roads
Wildfire
1, 2, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Low
MC-89
Provide grants to harden existing
structures against fires
Wildfire
1, 2, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Low
MC-90
Plant native fire-resistant vegetation Wildfire
1, 2, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Low
MC-91
Conduct brush clearance around
evacuation routes
Wildfire
1, 2, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Low
MC-92
Deploy livestock to remove
vegetation
Wildfire
1, 2, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Low
MC-93
Collaborate with land management
agencies to manage vegetation in
open space and common space
areas
Wildfire
1, 2, 5
Co County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Low
809
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
448
Table 4.9: Marin County Current Hazard Mitigation Actions No. Mitigation Action
Hazards
Mitigated/
Goals
Met
Jurisdiction/
Responsible
Agency
New,
Existing,
Completed,
Removed
Estimated Cost
and Potential
Funding Source
Timeline/
Priority Comments/Progress
MC-94
Provide direct assistance to property
owners in need of vegetation
management to improve defensible
space
Wildfire
1, 3, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Medium
MC-95
Retrofit any current roads, highways
and bridges to endure high
magnitude earthquakes in areas
with 0.55 or higher shaking intensity.
Earthquake
1, 2, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Low
MC-96
Establish policy for soft story homes Earthquake
1, 4, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Medium
MC-97
Research and assess current roads,
highways, and bridges probability to
endure a high magnitude
earthquake
Earthquake
1, 2, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC, BRIC
technical assistance
2-5 years
Low
MC-98
Replace or enhance water and
sewage pipes and joints within
areas vulnerable to liquefaction with
flex pipes or alternate infrastructure.
Earthquake
1, 2, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-10 years
Low
MC-99
Retrofit all County and City and
Town facilities to withstand large
earthquakes.
Earthquake
1, 2, 5
County of
Marin – OEM /
Fire, Cities and
Towns
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-10 years
Low
810
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
449
Table 4.9: Marin County Current Hazard Mitigation Actions No. Mitigation Action
Hazards
Mitigated/
Goals
Met
Jurisdiction/
Responsible
Agency
New,
Existing,
Completed,
Removed
Estimated Cost
and Potential
Funding Source
Timeline/
Priority Comments/Progress
MC-100
Identify pre-1933 school buildings
and critical infrastructure
Earthquake
1, 2, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Medium
MC-101
Retrofit all critical infrastructure to
resist severe earthquake shaking
above 0.55 intensity.
Earthquake
1, 2, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-15 years
Low
MC-102
Expand community outreach to
Great Shakeout Drill – Use Shaker
trailer
Earthquake
1, 3, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Medium
MC-103
Outreach to hospitals and other
critical care facilities on
infrastructure risk
Earthquake
1, 2, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Medium
MC-104
Conduct Research on impacts of
San Andreas Fault in West Marin
Earthquake
1, 2, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC, BRIC
technical assistance
2-5 years
Medium
MC-105
Provide outreach and education on
San Andreas Fault in West Marin
Earthquake
1, 3, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Medium
811
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
450
Table 4.9: Marin County Current Hazard Mitigation Actions No. Mitigation Action
Hazards
Mitigated/
Goals
Met
Jurisdiction/
Responsible
Agency
New,
Existing,
Completed,
Removed
Estimated Cost
and Potential
Funding Source
Timeline/
Priority Comments/Progress
MC-106
Study dam spillways and
emergency spillways, specifically for
seepage and to reassess geological
assumptions
Dam
Inundation
1, 2, 5, 6
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Low
MC-107
Widen dam spillways in areas where
dams may receive additional water
due to climate change
Dam
Inundation
1, 2, 5, 6
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
5-15 years
Low
MC-108
Harden dam spillway infrastructure
to prevent spillway failures during
controlled / emergency releases
Dam
Inundation
1, 2, 5, 6
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
5-15 years
Low
MC-109
Research effective methods to
strengthen wind load for existing
utilities and critical infrastructure
High Wind
1, 2, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC, BRIC
technical assistance
2-5 years
Low
MC-110
Conduct geotechnical survey of
slope stability county wide
Debris Flow
1, 2, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Low
MC-111
Seed and transplant fire resistant
and native plants and trees on
vulnerable sloped areas
Debris Flow
1, 2, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years
Low
812
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
451
Table 4.9: Marin County Current Hazard Mitigation Actions No. Mitigation Action
Hazards
Mitigated/
Goals
Met
Jurisdiction/
Responsible
Agency
New,
Existing,
Completed,
Removed
Estimated Cost
and Potential
Funding Source
Timeline/
Priority Comments/Progress
MC-112
Outreach and education to areas at
risk of debris flow
Debris Flow
1, 3, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-5 years,
ongoing
Medium
MC-113
Acquire land and or design new
codes for areas in high-risk
landslide areas and minimize new
construction via policy
recommendations
Debris Flow
1, 2, 4, 5
County of
Marin – OEM /
Fire
New TBD Cost
General
Funds/Grants
HMPG, BRIC
2-10 years
Low
MC-114
Marin County Structure Elevation
Program
Flooding
1, 2, 4, 5
County of
Marin - DPW
Existing, New $4M
General
Funds/Grants
(HMGP)
0-5 years
In progress
Provides federal
assistance to
homeowners with costeffective projects. FEMA
funding approved and 7
permits are being
reviewed
MC-115 Seismic Retrofit of County-owned
buildings not current to code.
Earthquake
1, 2, 5
County of
Marin - DPW
Existing
(2018)
TBD Cost
General
Funds/Grants
HMPG, BRIC
0-5 years
In progress
Staff also continue
gathering available
seismic assessment data
on County-owned (and
possibly leased sites in
the future) facilities. This
information will be
brought into an asset
management database,
which is in the early
stages of development,
and will support risk
assessment and work
plan development
813
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
452
Table 4.9: Marin County Current Hazard Mitigation Actions No. Mitigation Action
Hazards
Mitigated/
Goals
Met
Jurisdiction/
Responsible
Agency
New,
Existing,
Completed,
Removed
Estimated Cost
and Potential
Funding Source
Timeline/
Priority Comments/Progress
MC-116
Seismic Retrofit of County-owned
buildings not current to code. 120
N. Redwood- Seismic Assessment
Earthquake
1, 2, 5
County of
Marin - DPW,
CDA
Existing
(2018)
TBD Cost
General
Funds/Grants
HMPG, BRIC
0-5 years
In progress
Local hazard mitigation
by the States Office
MC-117
Seismic Retrofit of County-owned
buildings not current to code. Marin
Center- Seismic Assessment of the
Veteran's Memorial Auditorium &
Exhibit Hall
Earthquake
1, 2, 5
County of
Marin - DPW,
CDA
Existing
(2018)
TBD Cost
General
Funds/Grants
HMPG, BRIC
0-5 years
In progress
Completed assessment,
and HMGP grant secured
for upgrades. Seismic
retrofit work at the Exhibit
Hall completed in
November 2022. The
retrofit design work for
the Veterans' Memorial
Auditorium is complete.
Construction work
anticipated to run from
April 2023 thru January
2024.
MC-118 San Anselmo Flood Risk Reduction
Project.
Flooding
1, 2, 5
San Anselmo is
project lead
Existing
(2018)
$17.6M/ Flood Zone
9/
General
Funds/Grants (DWR,
HMGP application)
0-5 years
In progress
Construction of flood
detention basin on
Fairfax Creek was
substantially completed
and the basin operational
in November 2022.
Outfall pipe slide gate
can be operated
manually and pending
installation of electrical
paneling March 2023 for
electrical control
operation. The project to
remove the building
bridge in downtown San
Anselmo is in the final
planning phase
814
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
453
Table 4.9: Marin County Current Hazard Mitigation Actions No. Mitigation Action
Hazards
Mitigated/
Goals
Met
Jurisdiction/
Responsible
Agency
New,
Existing,
Completed,
Removed
Estimated Cost
and Potential
Funding Source
Timeline/
Priority Comments/Progress
MC-119
Arroyo Corte Madera del Presidio
Riverine (Corte Madera Creek)
Flood Risk Management Project
Flooding
1, 5
County of
Marin - DPW
Existing
(2018)
$14M/Flood Zone 9:
General
Funds/Grants (DWR,
applications for
FEMA, NOAA)
0-5 years
In progress
Construction in progress
through 2023 - The Marin
County Flood Control and
Water Conservation
District (District)
proposed the Corte
Madera Creek Flood Risk
Management Project,
Phase 1 to reduce the
25-year flood risk along
Corte Madera Creek in
the Town of Ross and
unincorporated Kentfield
and to enhance natural
stream functions. An
HMGP application for
components in the
channel that reduce flood
risk was submitted
August 4, 2023
MC-120 Azalea Ave Bridge Replacement Flooding
1, 5 Town of Fairfax
Existing
(2018) TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
0-5 years Town of Fairfax is project
lead.
MC-121 Nokomis Ave Bridge Replacement Flooding
1, 5
Town of San
Anselmo
Existing
(2018) TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
0-5 years Town of San Anselmo is
project lead.
MC-122 Madrone Ave Bridge Replacement Flooding
1, 5
Town of San
Anselmo
Existing
(2018) TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
0-5 years Town of San Anselmo is
project lead.
815
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
454
Table 4.9: Marin County Current Hazard Mitigation Actions No. Mitigation Action
Hazards
Mitigated/
Goals
Met
Jurisdiction/
Responsible
Agency
New,
Existing,
Completed,
Removed
Estimated Cost
and Potential
Funding Source
Timeline/
Priority Comments/Progress
MC-123 Winship Bridge Replacement Flooding
1, 5 Town of Ross
Existing
(2018) TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
0-5 years Town of Ross is the
project lead.
MC-124 Sycamore Ave bridge replacement Flooding
1, 5
Town of San
Anselmo
Existing
(2018) TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
0-5 years
Currently on hold. A
watershed study has
been scoped out, but not
enough funding has been
identified.
MC-125 Lower Corte Madera Creek
Improvements
Flooding
1, 5
County of
Marin - DPW
Existing
(2018) $2M/Flood Zone 9/
General
Funds/Grants (DWR)
0-5 years
In progress Currently on hold
MC-126
Continue supporting the Sonoma
County Water Agency led Advanced
Quantitative Precipitation
Information effort.
Flooding
1, 4, 5
County of
Marin - DPW
Existing
(2018)
$1.5M
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
0-5 years
In progress
Working to expand storm
drainage improvement
planning into Nave
Gardens through a Flood
District funded study
currently underway
through 2023. The study
is looking at ways of most
effectively bypassing high
flows and potential
options such as
increasing storage,
building flood barriers,
daylighting drainages,
and installing pump
stations and/or tide gates.
Funding for future
improvements would
likely be sought through
FEMA HMGP.
816
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
455
Table 4.9: Marin County Current Hazard Mitigation Actions No. Mitigation Action
Hazards
Mitigated/
Goals
Met
Jurisdiction/
Responsible
Agency
New,
Existing,
Completed,
Removed
Estimated Cost
and Potential
Funding Source
Timeline/
Priority Comments/Progress
MC-127
Pacheco Pond Project - flood flow
diversion to wetlands to improve
water quality and habitat. Upgrade
title gages.
Flooding
1, 5
County of
Marin - DPW
Existing
(2018) TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
0-5 years
In progress
Annual outreach
conducted in October
MC-128
Deer Island Basin Project to setback
levees, restore tidal wetlands, and
increase tidal prism to reduce
sedimentation and flood risk.
Flooding
1, 5
County of
Marin - DPW
Existing
(2018) $10M/ Flood Zone 1/
General
Funds/Grants
(SFBRA grant)
0-5 years
In progress
National Park Service is
working with FHWA and
the Flood District to
identify and plan a
potential overflow
channel from Easkoot
Creek to the Ocean.
MC-129 Rush Creek Drainage
Improvements
Flooding
1, 5
County of
Marin - DPW
Existing
(2018)
TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
2-3 years
Low
During final design of the
levee upgrade in
February 2022, the
engineer’s updated
construction cost
estimate came in at
$12M, exceeding the
project’s available
funding for project design
and construction. The
District continues to track
opportunities for project
construction funding.
MC-130 The upgrade Farmers, Cheda, and
Lynwood pump stations
Flooding
1, 5
County of
Marin - DPW
Existing
(2018)
TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
0-5 years
Low
Interim upgrades were
made by adding an in-line
check valve to prevent
tides from flooding
Meadow Dr. No funding
(or local match) currently
available for full
conceptual upgrades to
proceed to design.
817
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
456
Table 4.9: Marin County Current Hazard Mitigation Actions No. Mitigation Action
Hazards
Mitigated/
Goals
Met
Jurisdiction/
Responsible
Agency
New,
Existing,
Completed,
Removed
Estimated Cost
and Potential
Funding Source
Timeline/
Priority Comments/Progress
MC-131 City of Novato Drainage
Improvement
Flooding
1, 5
County of
Marin - DPW
Existing
(2018)
TBD Cost
General
Funds/Flood Zone 1/
FMA, DWR, HMGP,
BRIC
0-5 years
In progress Currently on hold
MC-132 Encourage property owners in
SFHAs to purchase flood insurance.
Flooding
1, 3, 5
County of
Marin - DPW,
OEM/Fire
Existing
(2018) TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
Ongoing
In progress Currently on hold
MC-133
Easkoot Creek Flood Flow Bypass
Project. (National Park Service/
FHWA project being scoped
currently as part of parking lot work)
Flooding
1, 5
County of
Marin - DPW
Existing
(2018) TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
0-5 years
In progress Currently on hold
MC-134
Santa Venetia Floodwall Project
(Formerly the Santa Venetia
Timber-Reinforced Berm
Improvement Project)
Flooding
1, 5
County of
Marin - DPW
Existing
(2018)
$12 Million
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
0-5 years
In progress
Coordinating with County
Engineering to include
drainage upgrades with
road rehabilitation
projects. Labrea Way,
vulnerable to recurrent
stormwater ponding, is
currently in design.
MC-135 Meadow Drive Interceptor and Ditch
Upgrades.
Flooding
1, 5
County of
Marin - DPW
Existing
(2018) TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
0-5 years
Low
Currently in design phase
for the placement of
100,000 cubic yards of
dredge sediment. Goal to
support navigation and
storm drain outfall.
MC-136 Santa Venetia Pump Station No. 4
Upgrades on hold
Flooding
1, 5
County of
Marin - DPW
Existing
(2018) $3M/ Flood Zone 7
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
0-5 years
In progress
In 2021, County and
Parks staff received a
grant from the San
Francisco Bay
Restoration Authority
(SFBRA) Measure AA
818
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
457
Table 4.9: Marin County Current Hazard Mitigation Actions No. Mitigation Action
Hazards
Mitigated/
Goals
Met
Jurisdiction/
Responsible
Agency
New,
Existing,
Completed,
Removed
Estimated Cost
and Potential
Funding Source
Timeline/
Priority Comments/Progress
Bay region wetlands
grant program. This grant
funding will allow the
McInnis Marsh
Restoration project to
continue work on final
design, compliance with
the California
Environmental Quality
Act (CEQA) and
permitting including the
proposed CSA 6 Gallinas
Creek geomorphic
dredge project. Note that
the proposed McInnis
Marsh Restoration project
is not currently funded for
implementation.
MC-137
Pump Station No. 2 Upgrade, and
interconnection to Pump Station No.
1 is currently on hold.
Flooding
1, 5
County of
Marin - DPW
Existing
(2018) $3M
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
0-5 years
In progress
Initiation of this project
depends on completion of
a land exchange through
State Lands Commission.
County is working on
surveying needed to
support that exchange.
MC-138 Pump Station No. 5 Upgrade Flooding
1, 5
County of
Marin - DPW
Existing
(2018) $3M
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
0-5 years
In progress Currently on hold
MC-139 Santa Venetia and Rafael Meadows
Street Drain Upgrades.
Flooding
1, 5
County of
Marin - DPW
Existing
(2018) TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
0-5 years
In progress
In 2022 all pump stations
in Santa Venetia were
upgrade to Trimble Unity
System for alerts and
notifications to staff.
Funding for additional
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Table 4.9: Marin County Current Hazard Mitigation Actions No. Mitigation Action
Hazards
Mitigated/
Goals
Met
Jurisdiction/
Responsible
Agency
New,
Existing,
Completed,
Removed
Estimated Cost
and Potential
Funding Source
Timeline/
Priority Comments/Progress
upgrades not available at
this time.
MC-140 Gallinas Creek Geomorphic Dredge Flooding
1, 5
County of
Marin - DPW
Existing
(2018)
$3M/ County Service
Area 6/
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
0-5 years
In progress
Flood district is
supporting the Town of
Tiburon's storm drainage
master plan
implementation out by
designing the upgrade to
the Cove Stormwater
Pump Station
(construction completed,
Project 33 in 2018 LHMP)
to have capacity to
handle the increased
flows that would be
conveyed to the station
by the full buildout of the
Town's master plan.
MC-141 McInnis Park Wetland Restoration
Project
Flooding
1, 5
County of
Marin - DPW
Existing
(2018) TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
0-5 years
In progress Currently on hold
MC-142 Levee Setback and Upgrade
Project.
Flooding
1, 5
County of
Marin - DPW
Existing
(2018) TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
0-5 years
In progress
Integrated into future sea
level rise adaptation
planning.
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Table 4.9: Marin County Current Hazard Mitigation Actions No. Mitigation Action
Hazards
Mitigated/
Goals
Met
Jurisdiction/
Responsible
Agency
New,
Existing,
Completed,
Removed
Estimated Cost
and Potential
Funding Source
Timeline/
Priority Comments/Progress
MC-143 Pump Station No. 1 Upgrade Flooding
1, 5
County of
Marin - DPW
Existing
(2018) $2M
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
0-5 years
In progress
On hold due to lack of
property owner
easements. Considering
a creek restoration
project instead.
MC-144 Estancia Ditch and Pump Station
improvement project
Flooding
1, 5
County of
Marin - DPW
Existing
(2018)
$4M/ Flood Zone 7/
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
0-5 years
In progress
Coordinating with
Caltrans on a scheduled
2024 pavement
rehabilitation project to
potentially include tide
gates to reduce sunny
day flooding of Tiburon
Blvd.
MC-145 Tiburon Street Drainage
Improvements Plan
Flooding
1, 5
County of
Marin - DPW
Existing
(2018) TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
0-5 years
In progress
A levee study was
completed, and a portion
of the levee system has a
project underway for
seepage mitigation. It is
in the design phase.
MC-146 Karen Way Ditch Improvements Flooding
1, 5
County of
Marin - DPW
Existing
(2018) TBD Cost/ Flood
Zone 4/ General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
0-5 years
In progress
Currently in the planning
phase of project.
MC-147 Strawberry Levee Improvements
Sea Level
Rise
1, 5
County of
Marin - DPW
Existing
(2018) $1M / Flood Zone 4/
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
0-5 years
In progress
Integrated into future sea
level rise adaptation
planning.
MC-148 West Creek Flood Wall Alternative
Restoration Project
Flooding
1, 5
County of
Marin - DPW
Existing
(2018) TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
5-10 years
In progress
The district is working
with the County's Parks
Department to evaluate a
potential pilot project for
thin-lift placement of
sediment from Coyote
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Table 4.9: Marin County Current Hazard Mitigation Actions No. Mitigation Action
Hazards
Mitigated/
Goals
Met
Jurisdiction/
Responsible
Agency
New,
Existing,
Completed,
Removed
Estimated Cost
and Potential
Funding Source
Timeline/
Priority Comments/Progress
Creek in Bothin Marsh. It
would require a Measure
AA grant to design,
permit, construct, and
monitor.
MC-149 East Creek Outfall Modifications
Project
Flooding
1, 5
County of
Marin - DPW
Existing
(2018)
$10M/ Flood Zone 4/
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
3 years
In progress
Caltrans is working on a
project initiation
document for December
2023 for sea level rise
adaptation at the US
101/SR 1 between
Manzanita and Marin
City. County is supporting
this work through
hydraulic studies.
MC-150 Coyote Creek Levee Improvements Flooding
1, 2, 5
County of
Marin - DPW
Existing
(2018) $40M/ Flood Zone 3/
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
0-5 years
In progress Currently on hold
MC-151 Marin City Drainage Improvements
Project
Flooding
1, 5
County of
Marin - DPW
Existing
(2018)
TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
0-5 years
In progress
Following the condition
assessment design will
proceed in 2024. After
construction of the crest
Marin improvements a
study of Cardinal and
shoreline pump stations
and associated drainage
is anticipated.
MC-152
Richardson Bay Shoreline
Protection work is to be integrated
into future sea level rise adaptation
planning.
Sea Level
Rise
1, 5
County of
Marin - DPW
Existing
(2018)
$150M
TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
5-10 years
In progress
County maintains a flood
preparedness webpage
with resources and
information for
landowners.
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Table 4.9: Marin County Current Hazard Mitigation Actions No. Mitigation Action
Hazards
Mitigated/
Goals
Met
Jurisdiction/
Responsible
Agency
New,
Existing,
Completed,
Removed
Estimated Cost
and Potential
Funding Source
Timeline/
Priority Comments/Progress
MC-153 Bothin Marsh Restoration project Flooding
1, 5
County of
Marin - DPW
Existing
(2018)
$2.4 M
General
Funds/Flood Zone
3/Grants (SFBRA
application in
progress)
5-10 years
In progress
Ongoing through Local
Coastal Program update,
funded and completed,
nature-based adaptation
studies, and the Safety
Element update.
MC-154
Manzanita Modifications Project. To
support/supplement a Caltrans
project
Flooding,
Sea Level
Rise
1, 5
County of
Marin - DPW
Existing
(2018) TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
0-5 years
In progress
Funded through Ocean
Protection Council grant
and AARPA funds.
Ongoing Stinson Beach
Adaptation and
Resilience Collaboration
(Stinson ARC) project.
MC-155 Lower Ryan Creek Pump Station
Study and Upgrades
Flooding
1, 5
County of
Marin - DPW
Existing
(2018) $2.5M/ Flood Zone 3/
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
5-10 years
In progress
Project has not started
due to lower community
priority. However, the
project has not been
abandoned and may be
completed in the next
year.
MC-156 Crest Marin, Cardinal, and Shoreline
Pump Station Upgrades.
Flooding
1, 5
County of
Marin - DPW
Existing
(2018)
$7.5M/ Floods Zone
3/
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
0-5 years
In progress
Two funded and
completed nature-based
studies explored the
feasibility of these
projects and follow up
work is now happening
through the Stinson ARC
project and through
pursuit of other grant
opportunities.
MC-157 Flood Preparedness Pilot Program Flooding
1, 3, 5
County of
Marin - DPW
Existing
(2018) Negligible cost
General funds
0-5 years
In progress In Progress
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Table 4.9: Marin County Current Hazard Mitigation Actions No. Mitigation Action
Hazards
Mitigated/
Goals
Met
Jurisdiction/
Responsible
Agency
New,
Existing,
Completed,
Removed
Estimated Cost
and Potential
Funding Source
Timeline/
Priority Comments/Progress
MC-158
Consider sea level rise adaptation
from Collaboration: Sea-level Marin
Adaption Response Team (CSMART).
Sea Level
Rise
1, 4, 5
County of
Marin - DPW
Existing
(2018) TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
Ongoing
In progress
MC-159 Initiate Community Plans for
Adapting to Coastal Hazards
Flooding,
Sea Level,
Rise,
Tsunami
1, 2, 3, 5
County of
Marin - DPW
Existing
(2018) TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
Ongoing
In progress
MC-160
Develop Renters and Homeowners
Guides to Flood Preparedness
project
Flooding
1, 3, 5
County of
Marin - DPW,
OEM
Existing
(2018) TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
0-5 years
Low
MC-161 Protect and restore natural buffers. Flooding
1, 5
County of
Marin - DPW
Existing
(2018) TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
Ongoing
In progress
MC-162 Assess bulkheads surrounding
Tomales Bay
Flooding
(coastal)
1, 5
County of
Marin - DPW
Existing
(2018) TBD Cost
General
Funds/Grants/ FMA,
DWR, HMGP, BRIC
Ongoing
In progress
Table 4.9: Marin County Current Hazard Mitigation Actions Source: Marin County
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4.7 PLAN INTEGRATION
For hazard mitigation planning, “integration” means that hazard mitigation information is used in other relevant planning mechanisms, such as general planning, capital facilities planning, emergency management, hazard specific planning, and that relevant information from those sources is also used in hazard mitigation. This section identifies where such integration is already in place from the 2018 MJHMP, and where the 2023 MJHMP will be used for further integration.
The Marin County Office of Emergency Management will be the central coordination point for maintaining this plan and will serve as a lead staff for grant project applications on the countywide projects selected for application under the Hazard Mitigation Assistance grant programs. Additionally, each participating jurisdiction applying for grant funds on its own will serve as lead staff for project implementation with assistance from the County and participating Steering Committee members as requested.
An important integration mechanism that is highly effective and low-cost is incorporation of the hazard mitigation plan recommendations and their underlying principles into other county, city and town plans and mechanisms. Where possible, plan participants will use existing plans and/or programs to implement hazard mitigation actions. Mitigation is most successful when it is incorporated into the day-to-day functions and priorities of government and development. As described in this plan’s capability assessment, Marin County and its jurisdictions already implement policies and programs to reduce losses to life and property from hazards. This plan builds upon the momentum developed through previous and related planning efforts and mitigation programs and recommends implementing actions, where possible, through these other program mechanisms. These existing mechanisms include:
• County, City and Town general and master plans - Integrates hazard mitigation through the consideration of hazards most likely to impact the County. These hazards are considered in the Safety Element, Housing Element and Open Space Element. • County, City and Town Emergency Operations Plans - Integrates hazard mitigation through the consideration of the Town’s planned response to hazards most likely to impact the Town.
• County, City and Town ordinances - Integrates hazard mitigation through the consideration of plans and policies outlined in the capability assessments in the jurisdictional annexes.
• Flood/storm water management/master plans - Integrates hazard mitigation through the consideration of strategies to reduce flood risk and storm water management for the protection of life and property.
• Community Wildfire Protection plan - Integrates hazard mitigation through the consideration of strategies to reduce fire hazard and the risk of catastrophic wildfires in the WUI, while promoting the protection and enhancement of the county’s economic assets and ecological resources.
• Capital improvement plans and budgets - Integrates hazard mitigation through the consideration of strategies for the development and funding a critical facilities and infrastructure.
• Other plans and policies outlined in the capability assessments in the jurisdictional annexes.
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• Other plans, regulations, and practices with a mitigation focus Steering Committee members involved in these other planning mechanisms will be responsible for integrating the findings and recommendations of this plan with these other plans, programs, etc., as appropriate. Implementation and incorporation into existing planning mechanisms will be done through the routine actions of:
• Monitoring other planning/program agendas
• Attending other planning/program meetings
• Participating in other planning processes
• Monitoring community budget meetings for other community program opportunities The successful implementation of this mitigation strategy will require constant and vigilant review of existing plans and programs for coordination and multi-objective opportunities that promote a safe, sustainable community. A few examples of incorporation of the MJHMP into existing planning mechanisms include:
1) As recommended by Assembly Bill 2140, each community should adopt (by reference or incorporation) this MJHMP into the Safety Element of their General Plans. Evidence of adoption (by formal, certified resolution) shall be provided to CalOES and FEMA 2) Integration of flood actions identified in this mitigation strategy with the actions and implementation priorities established in existing Flood Management Programs 3) Using the risk assessment information to update the hazards section in the County, City and Town Emergency Operations Plans
Efforts should continuously be made to monitor the progress of mitigation actions implemented through these other planning mechanisms and, where appropriate, their priority actions should be incorporated into updates of this hazard mitigation plan.
4.8 FUTURE DEVELOPMENT TRENDS
Marin County’s abundance of natural, recreational, and scenic resources has supported a long history of open space preservation. Its rolling hills, expansive ranchlands, beaches, coastlines, and more are appreciated by both visitors and locals alike. This quote, from the Marin Independent Journal 1934 Editorial captures this sentiment:
"No community on earth is more favored than Marin with the wealth and beauty of potential playgrounds. If we don’t acquire some of these lands, the opportunity will surely slip away from us.”
In the 1960s, housing/transportation development proposals were underway throughout Marin County including for the Marin Headlands, outer coast, Tomales Bay area and more. Such proposals threatened Marin’s rural character and long heritage of family farming, sparking community activism which drew national attention. These efforts led to the employment of land use planning tools to ensure the County’s natural and agricultural areas remain protected in perpetuity. Establishment of the Point Reyes National Seashore in 1962, and a handful of other Federal/State Park units, ensured the protection of a large amount of the County’s most 826
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cherished lands as publicly accessible open space. Additionally, the Marin Agricultural Land Trust, established in 1980, has placed agricultural conservation easements on over 60,000 acres of farmland, to ensure protection from development in perpetuity.
Furthermore in 1972 the California Coastal Commission was established as a regulatory agency whose mission is “To protect, conserve, restore, and enhance the environment of the California coastline”. Pursuant to the California Coastal Act of 1976, the agency is tasked with the protection of a variety of resources including public access, habitat, and water quality. The Commission issues Coastal Development Permits, until a local agency has a certified Local Coastal Program (LCP), with a land use plan and implementation plan.
West Marin’s coastal zone covers approximately 82,168 acres. Of this approximately 33,913 acres are owned and managed by the National Park Service, leaving 48.255 acres under County Jurisdiction subject to the LCP. This encompasses a handful of small communities along the Pacific Coast and Tomales Bay shorelines including Muir Beach, Stinson Beach, Bolinas, Inverness, Point Reyes Station, East Shore and Dillon Beach. New growth in these communities is limited by a variety of factors including few remaining undeveloped parcels; land use policies and plans which protect public access and natural resources; and environmental features such as the coast itself, Tomales Bay, and steep bluffs which naturally restrain development.
Development in the County over the last 5 years has been limited due to build out, and similarly future development is limited by these same constraints. For this reason, development related considerations to plan updates were not applicable to the planning process. Instead, the plan was revised to consider regional development trends and incorporation of new science such as potential climate change impacts.
Marin County has focused on sea level rise planning and climate action for several years.
Currently, the LCP is being updated to reflect the changing risks to coastal areas and develop appropriate policies and actions to avoid and minimize the risk of disaster and harm to its residents, infrastructure and coastal resources. Coastal Act policies Sections 30210, 30240, and 30251 dictate that new development shall be safe from hazards and recognize that shoreline protective devices such as seawalls may be appropriate in certain instances to serve coastaldependent uses or to protect existing structures or public beaches in danger from erosion.
However, shoreline protective devices must be designed to eliminate or mitigate the adverse impacts on the sand supply of surrounding natural shorelines. Other development-limiting Coastal Act policies include:
Section: 30210: Development shall not interfere with the public’s right of access to the sea including the use of beaches
Section 30240: Environmentally Sensitive Habitat Areas (ESHA) shall be protected.
Section 30251: The scenic and visual qualities of coastal areas shall be considered and protected as resources of public importance.
The 2040 population projection for Marin County is 277,087 (Department of Finance). In order to accommodate population growth over the next several years, Marin County and its incorporated cities have implemented a number of land use plans and development policies to direct growth away from hazardous conditions. For example, as required by state law, the County and each 827
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incorporated city have a general plan with a safety element that identifies hazards affecting the County and incorporated cities. Likewise, the County and the incorporated cities have a number of planning policies, such as floodplain ordinances and building codes, restricting new development in hazard areas and/or increasing construction requirements in hazard areas.
In addition to steering away growth from hazard areas, Marin County and its incorporated cities have a history of aggressive growth management that seeks to limit growth overall and to direct it within the incorporated cities and urban areas of the unincorporated County.
The 2007 Marin Countywide Plan was last updated in 2015 to reflect the theme of planning for sustainable communities. Twelve principles support this theme including the preservation of natural assets and the protection of agricultural assets in order to minimize development in open space. The plan is divided into specific elements, each with goals, policies, and implementation programs. The Plan’s land use pattern reflects existing development potential shifted to a degree from environmentally constrained sites to more appropriate locations. Specific Countywide Plan policies which limit urban development through the protection of open space resources include:
• Biological Resources 1.1 Protect Wetland Habitats for Special-Status Species, Sensitive Natural Communities, and Important Wildlife Nursery Areas and Movement Corridors. • Biological Resources 1.2 Acquire Habitat
• Biological Resources 2.1 Include Resource Preservation in Environmental Review Biological Resources 2.2 Limit Development Impacts
• Biological Resources 3.1 Protect Wetlands
• Biological Resources 4.1 Restrict Land Use in Stream Conservation Areas • Biological resources 5.1 Protect the Baylands Corridor • Biological Resources 5.2 Limit Development and Access • Biological Resources 5.3 Leave Tidelands in Their Natural State • Air 4.m Focus Development in Urban Corridors
• Open Space 2.2 Continue to Acquire or Otherwise Preserve Open Space Countywide Open Space 2.4 Support Open Space Efforts Along Streams • Open Space 2.5 Support Open Space Efforts in the Inland Rural Corridor • Open Space 2.6 Support Open Space Efforts in the Coastal Corridor • Agriculture 1.1 Limit Residential Use
• Agriculture 1.2 Encourage Contractual Protection
• Agriculture 1.3 Preserve Agricultural Zoning
• Agriculture 1.4 Limit Non-Agricultural Zoning
• Agricultural 1.5 Restrict Subdivision of Agricultural Lands Within the Coastal, Inland Rural and Baylands Corridors
• Agriculture 1.6 Limit Non-Agricultural Development
• Additionally, the Plan includes policies to limit development in hazardous areas, including:
• Environmental Hazards 3.a Regulate Development in Flood and inundation Areas • Environmental Hazards 3.e Restrict Development in Flood Prone Areas • Environmental Hazards 4.1 Limit Fire Risks to Structures 828
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Implementation tools such as the County Development Code are used to carry out Countywide Plan goals. Some of the policies and programs in the Countywide Plan will require rezoning of individual properties for consistency with land use designations and policies. Furthermore, many unincorporated communities are guided by community plans which may include customized building and site design standards, ridgeline and view corridor protection mechanisms, home size regulations and more.
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SECTION 5.0: PLAN REVIEW, EVALUATION, AND
IMPLEMENTATION
The strategies presented are deemed appropriate and effective by recommendation of the Marin County OA Hazard Mitigation Steering Committee, senior management of local governments and public agencies, and individual organizations and groups that have participated in its creation, or reviewed the end product.
5.1 PLAN ADOPTION
Upon submission to the California Office of Emergency Services (CalOES) for review, and subsequent approval by the Federal Emergency Management Agency (FEMA), the Marin County OA MJHMP will be presented to local government for formal adoption. It will then be incorporated into local general plans for integration into organizational policy.
5.2 PLAN MONITORING AND PUBLIC ENGAGEMENT
The process of hazard mitigation does not end with the completion, approval, and adoption of the Marin County OA MJHMP. During the five-year lifespan the Marin plan, the County, cities, towns and special districts, along with community-based organizations will ensure that the mitigation goals and strategies identified are exercised and monitored under a collaborative and cooperative umbrella, and that the document itself is properly maintained.
The Marin County Office of Emergency Management, as lead coordinating agency for hazard mitigation planning within the Marin County OA, leads the Marin Operational Area Hazard Mitigation Working Group that meets quarterly to review and manage the plan, projects, and programs. The review will identify changing community priorities, updated or new planning documents and the progress or status of the mitigation actions as detailed in the mitigation strategy. Additional questions to complete the review will be considered as follows:
• Do the goals address current and expected conditions? • Are the goals and objectives consistent with changes in the local, state, and federal policy?
• Status updates on all mitigation actions?
• Have the hazards or risks changed?
• Are current resources appropriate for implementing the MJHMP? • Have the outcomes occurred as expected?
44 CFR Requirement §201.6(d)(3) A local jurisdic�on must review and revise its plan to reflect changes in development, progress in local mi�ga�on efforts, and changes in priori�es, and resubmit if for approval within 5 years in order to con�nue to be eligible for mi�ga�on project grant funding. §201.6(d)(5) [The plan shall include…] Documenta�on that the plan has been formally adopted by the governing body of the jurisdic�on reques�ng approval of the plan (e.g., City Council, County commissioner, Tribal Council). For mul�‐jurisdic�onal plans, each jurisdic�on reques�ng approval of the plan must document that it has been formally adopted. 830
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• Is the County and jurisdictions or districts participating in the plan implementation process as expected?
The Working Group is a subgroup of the Marin Disaster and Citizens Corps Council. During the five-year update cycle, the Marin Operational Area Hazard Mitigation Working Group will have quarterly update meetings with the Hazard Mitigation Planning Committee and local stakeholders to discuss revisions to the plan and progress updates for the hazard mitigation actions. Further, Marin OEM will host an annual one-day mitigation summit to increase engagement and enhance collaboration on the plan and projects. The summit will also have the goal to educate stakeholders on innovative approaches to mitigation, trends, and new plan requirements. Marin OEM, as the host, will seek subject matter experts, state and federal officials, and representatives from within the Marin OA to speak to mitigation and planning. The knowledge gathered and the coordination facilitated during the summit will be used to update the base plan and annexes.
Marin OEM has the capacity to lead the Working Group and Multi-Jurisdictional Planning with one coordinator assigned with direct maintenance of the plan, a department analyst assigned to support the coordinator with project and grant tracking, and a community preparedness coordinator assigned with conducting regular public outreach on the plan and education on mitigation. Community feedback and integration will continue through outreach events and OEM website, where residents and visitors are invited to provide feedback through a survey, available in English or Spanish.
Specific plan maintenance activities by the Marin County Office of Emergency Management and its participating jurisdictions/special districts may include:
• Hold quarterly update meetings with the Hazard Mitigation Planning Committee and local stakeholders to discuss revisions to the plan and progress updates for the hazard mitigation actions.
• Annual Hazard Mitigation Summit
• Holding public meetings after the first quarter and third quarter update meetings. • Maintaining the Marin County OEM Hazard Mitigation Website, which provides the public with the ability to access identified hazard impact maps, location address search capability, and a listing of hazard mitigation actions. • Monitoring of the Marin County and all participating jurisdiction mitigation project activities and dissemination of status reports.
• Generation of reports relative to plan status, project management, and revision updates to executive leadership.
• Preparations for the plan’s future revision and updating.
5.3 PLAN EVALUATION
Upon approval and adoption by Marin County and all participating jurisdictions, the prioritized mitigation strategies will be further developed for funding and implementation by the lead agencies. The plan describes the potential sources of hazard mitigation funding, and general procedures to obtain that funding.
The mitigation strategies represented and adopted within this plan are recommendations only and must be approved and funded in order to be implemented as official mitigation solutions.
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strategies, funding availability, and local need when it arises. The Marin County Office of Emergency Management will meet with the Marin Operational Area Hazard Mitigation Working Group to evaluate the plan after each update meeting.
5.4 PLAN UPDATE
During the five-year update cycle, the Marin County Office of Emergency Management will be responsible for updating the MJHMP. This update process will begin in 2024 through quarterly update meetings by the Marin Operational Area Hazard Mitigation Working Group and local stakeholders. The Marin OEM will lead these meetings to discuss revisions to the plan and progress updates for the hazard mitigation actions. Additional plan update actions are described in 5.2 Plan Monitoring and Public Engagement. The Marin County Office of Emergency Management and all participating jurisdictions and special districts will continue to hold public meetings after the first quarter and third quarter update meetings annually and will continue to invite public participation in the update process via updated public surveys. 832
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FIGURES AND TABLES INDEX
FIGURES
Figure 1.1: Map of Marin County ................................................................................................13 Figure 1.2: Fire Protection Districts in Marin County ..................................................................21 Figure 1.3: School Districts in Marin County...............................................................................22 Figure 1.4: Muir Woods National Monument...............................................................................23 Figure 1.5: Marin County Parks and Public Lands......................................................................24 Figure 1.6: Population of Marin County 1860-2020 ....................................................................25 Figure 1.7: Marin County Environmental Corridors.....................................................................34 Figure 1.8: Marin County Habitat Types .....................................................................................35 Figure 1.9: Marin County Wetlands.............................................................................................37 Figure 1.10: Marin County Watersheds ......................................................................................38 Figure 1.11: Marin County Geologic Units (East of San Andreas Fault) .....................................44 Figure 1.12: Marin County Geologic Units (West of San Andreas Fault)....................................45 Figure 1.13: Marin County Mineral Resource Sites ....................................................................46 Figure 1.14: Marin County Average Precipitation 1895-2022 .....................................................47 Figure 1.15: Marin County Average Temperature 1895-2022 .....................................................48 Figure 1.16: Diablo Wind Patterns ..............................................................................................48 Figure 1.17: Historic Sites in Marin County.................................................................................54 Figure 1.18: Generalized NRI Risk Equation ..............................................................................55 Figure 1.19: Marin County NRI – Expected Annual Loss............................................................62 Figure 1.20: Marin County National Risk Index Map ..................................................................63 Figure 1.21: Marin County CDC Social Vulnerability Index Map.................................................65 Figure 2.1: Marin County OEM MJHMP Website........................................................................94 Figure 2.2: Marin County OA MJHMP Town Hall Meeting ..........................................................95 Figure 2.3: Collecting community feedback on the MJHMP .......................................................96 Figure 2.4: Hazard Mitigation Plan Public Outreach Press Release...........................................97 Figure 2.5: Hazard Mitigation Plan Survey .................................................................................98 Figure 3.1: Marin County Risk Assessment – Top Hazards Graphed....................................... 111 Figure 3.2: NASA Global Temperature Change CO2 Gas ........................................................ 113 Figure 3.3: NASA Global Temperature Change 1884 to 2022 .................................................. 113 Figure 3.4: NASA Global Temperature Change Sea Level ....................................................... 114 Figure 3.5: Human Health Impacts from Climate Change ........................................................ 115 Figure 3.6: Annual Mean Sea Level Trends.............................................................................. 117 Figure 3.7: California Climate Impact Regions ......................................................................... 118 Figure 3.8: Dams in and around the Marin County OA.............................................................124 Figure 3.9: Marin County Dam Inundation Susceptibility to Critical Facilities ...........................125 Figure 3.10: Phoenix Lake Dam Inundation Area .....................................................................127 Figure 3.11: Phoenix Lake Dam Inundation Area – Kentfield North..........................................128 Figure 3.12: Phoenix Lake Dam Inundation Area – Kentfield South.........................................129 Figure 3.13: Novato Creek/ Stafford Lake Dam Inundation Area..............................................130 Figure 3.14: Novato Creek Dam Inundation Area – Green Point and Bel Marin Keys..............131 Figure 3.15: Bon Tempe Dam Inundation Area.........................................................................132 833
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Figure 3.16: Bon Tempe Dam Inundation Area – Lagunitas-Forest Knolls-San Geronimo Area ..................................................................................................................................................133 Figure 3.17: Bon Tempe Dam Inundation Area – Point Reyes Station Area South...................134 Figure 3.18: Bon Tempe Dam Inundation Area – Point Reyes Station Area North and Inverness ..................................................................................................................................................134 Figure 3.19: Peters Dam Inundation Area.................................................................................135 Figure 3.20: Peters Dam Inundation Area – Lagunitas-Forest Knolls Area ..............................136 Figure 3.21: Peters Dam Inundation Area – Point Reyes Station Area.....................................137 Figure 3.22: Alpine Dam Inundation Area .................................................................................138 Figure 3.23: Alpine Dam Inundation Area – Point Reyes Station..............................................139 Figure 3.24: Lagunitas Dam Inundation Area ...........................................................................140 Figure 3.25: Seeger Dam Inundation Area ...............................................................................141 Figure 3.26: Seeger Dam Inundation Area – Point Reyes Station East....................................142 Figure 3.27: Seeger Dam Inundation Area – Point Reyes Station West...................................143 Figure 3.28: Big Rock Ranch Dam Inundation Area .................................................................144 Figure 3.29: Big Rock Ranch Dam Inundation Area East .........................................................145 Figure 3.30: Big Rock Ranch Dam Inundation Area West ........................................................146 Figure 3.31: Soulajule Dam Inundation Area ............................................................................147 Figure 3.32: Soulajule Dam Inundation Area around Soulajule Dam........................................148 Figure 3.33: Soulajule Dam Inundation Area – Walker Creek at Highway 1.............................149 Figure 3.34: Soulajule Dam Inundation Area – Walker Creek at Highway 1 and Tomales Bay 149 Figure 3.35: Vonsen Dam Inundation Area ...............................................................................150 Figure 3.36: Vosen Dam Inundation Area .................................................................................151 Figure 3.37: Landslide Susceptibility Classes...........................................................................156 Figure 3.38: Mud Flow Areas ....................................................................................................157 Figure 3.39: Landslide Susceptibility in the Marin County OA..................................................158 Figure 3.40: Marin County Landslide Susceptibility for Critical Facilities Map..........................159 Figure 3.41: Landslide Susceptibility – Lagunitas, Forest Knolls, San Geronimo and Woodacre ..................................................................................................................................................160 Figure 3.42: Landslide Susceptibility – Nicasio and Tocoloma .................................................160 Figure 3.43: Landslide Susceptibility – Olema and Point Reyes Station ..................................161 Figure 3.44: Landslide Susceptibility – Inverness.....................................................................161 Figure 3.45: Landslide Susceptibility – Dillon Beach and Tomales...........................................162 Figure 3.46: Landslide Susceptibility – Dogtown, Bolinas and Stinson Beach .........................162 Figure 3.47: Landslide Susceptibility – Southern Marin County ...............................................163 Figure 3.48: Landslide Susceptibility – West Central Marin County .........................................164 Figure 3.49: Landslide Susceptibility – Novato West................................................................165 Figure 3.50: Landslide Susceptibility – West Central Marin County .........................................166 Figure 3.51: Landslide Susceptibility – North Novato ...............................................................167 Figure 3.52: Landslide Inventory in the Marin County OA ........................................................168 Figure 3.53: Damage in Inverness from the January 1982 Storm ............................................169 Figure 3.54: January 1982 Highway 101 Mudslide in Marin County.........................................169 Figure 3.55: February 2017 Landslide on Lucas Valley Road ..................................................170 Figure 3.56: March 2023 Mudslide in Marin County .................................................................171 Figure 3.57: U.S. Drought Monitor for California (2023) ...........................................................177 Figure 3.58: U.S. Drought Monitor for California (2020) ...........................................................178 Figure 3.59: U.S. Drought Monitor for California (2016) ...........................................................179 834
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Figure 3.60: Water Supply Conditions in California 2005-2018 ................................................179 Figure 3.61: Drought Impacts ...................................................................................................181 Figure 3.62: 2022 Locations of Tree Mortality in the Marin County OA ....................................182 Figure 3.63: Modified Mercalli Intensity Scale ..........................................................................185 Figure 3.64: Mercalli Scale vs. Magnitude ................................................................................186 Figure 3.65: Soil Types .............................................................................................................186 Figure 3.66: Earthquake Faults and Probability of Shaking in the Marin County OA ...............188 Figure 3.67: Marin County Earthquake Shaking Potential and Critical Facilities ......................189 Figure 3.68: Uniform California Earthquake Rupture Forecast Version 3.................................192 Figure 3.69: Population/Social Vulnerability to an Earthquake in California .............................195 Figure 3.70: Diagram of an Atmospheric River Event...............................................................198 Figure 3.71: FIRM Zones in the Marin County OA....................................................................199 Figure 3.72: The 100-year, 200-year and 500-year floodplains in the Marin County OA..........200 Figure 3.73: 100, 200, 500-Year Floodplains in the Marin County OA......................................201 Figure 3.74: 100-Year Floodplain – Lagunitas ..........................................................................202 Figure 3.75: 100-Year Floodplain – Forest Knolls Area ............................................................203 Figure 3.76: 100-Year Floodplain – San Geronimo Area ..........................................................203 Figure 3.77: 100-Year Floodplain – Woodacre Area .................................................................204 Figure 3.78: 100-Year Floodplain – Tocoloma ..........................................................................204 Figure 3.79: 100-Year Floodplain – Nicasio..............................................................................205 Figure 3.80: 100-Year Floodplain –Nicasio East.......................................................................206 Figure 3.81: 100-Year Floodplain –Olema ................................................................................206 Figure 3.82: 100-Year Floodplain – Point Reyes Station Area - South .....................................207 Figure 3.83: 100-Year Floodplain – Point Reyes Station Area - North......................................208 Figure 3.84: 100-Year Floodplain – Inverness Park Area .........................................................209 Figure 3.85: 100-Year Floodplain – Inverness South................................................................210 Figure 3.86: 100-Year Floodplain – Inverness .......................................................................... 211 Figure 3.87: 100-Year Floodplain – Reynolds and Marconi Area..............................................212 Figure 3.88: 100-Year Floodplain – Marshall Area....................................................................213 Figure 3.89: 100-Year Floodplain – Tomales Area ....................................................................214 Figure 3.90: 100-Year Floodplain – Bolinas North ....................................................................215 Figure 3.91: 100-Year and 500-Year Floodplain – Bolinas and Stinson Beach West ...............216 Figure 3.92: 100-Year and 500-Year Floodplain – Stinson Beach ............................................217 Figure 3.93: 100-Year and 500-Year Floodplain – Muir Beach .................................................218 Figure 3.94: 100-Year and 500-Year Floodplain – Tamalpais Valley Area ................................218 Figure 3.95: 100-Year and 500-Year Floodplain – Alto and Strawberry....................................219 Figure 3.96: 100-Year and 500-Year Floodplain – Kentfield and Greenbrae ............................220 Figure 3.97: 100-Year Floodplain – Marin City..........................................................................221 Figure 3.98: 100-Year Floodplain – Lucas Valley and Marinwood ............................................222 Figure 3.99: 100-Year Floodplain – Saint Vincent.....................................................................223 Figure 3.100: 100-Year and 500-Year Floodplain – Santa Venetia Area...................................223 Figure 3.101: 100-Year and 500-Year Floodplain – San Pedro Hill Area..................................224 Figure 3.102: Novato Flooding - Marin County Landfill and Marin County airport ...................225 Figure 3.103: Flooding in San Rafael Area ...............................................................................226 Figure 3.104: 100-Year Floodplain – Bel Marin Keys................................................................227 Figure 3.105: Stinson - Bolinas Area Flooding..........................................................................228 Figure 3.106: Flood Control Zones in the Marin County OA.....................................................229 835
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Multi-Jurisdictional Hazard Mitigation Plan
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Figure 3.107: Damage in Inverness from 1982 Storm ..............................................................231 Figure 3.108: Flooding in Marin City – 2019 Storm ..................................................................232 Figure 3.109: Population/Social Vulnerability to Flooding in California.....................................240 Figure 3.110: Dissolution Sinkhole Formation...........................................................................241 Figure 3.111: Cover-Subsidence Sinkhole Formation...............................................................242 Figure 3.112: Cover-Collapse Sinkhole Formation ...................................................................242 Figure 3.113: Land Subsidence in California 2007-2018 with Marin County Cutout.................243 Figure 3.114: U.S. Rock types Susceptible to Water Dissolution..............................................244 Figure 3.115: Levee Failure Mechanisms .................................................................................247 Figure 3.116: Marin County Levee System...............................................................................249 Figure 3.117: Levees in Tamalpais Valley .................................................................................250 Figure 3.118: Levees in Strawberry ..........................................................................................251 Figure 3.119: Tam Junction Levees ..........................................................................................252 Figure 3.120: Levee in Kentfield ...............................................................................................253 Figure 3.121: Greenbrae Levee System...................................................................................254 Figure 3.122: McNears Sea Wall in the San Pedro Hill Area....................................................255 Figure 3.123: Santa Venetia Levee in Santa Venetia ...............................................................256 Figure 3.124: Marin Levee 33, Marin County Levees 33 and 24 and the Las Gallinas Valley Sanitary District Levee in St. Vincent........................................................................................257 Figure 3.125: Santa Venetia Levee System..............................................................................258 Figure 3.126: Bel Marin Keys Levee System............................................................................259 Figure 3.127: Levees Around the Marin County Airport............................................................260 Figure 3.128: Novato North Levee System...............................................................................261 Figure 3.129: Marin County Sea Level Rise Susceptibility to Critical Facilities ........................267 Figure 3.130: Average July Temperatures in California ............................................................268 Figure 3.131: Projections of Sea Level Rise in the San Francisco Bay Area, 2000-2100 ........275 Figure 3.132: Heat Index .........................................................................................................276 Figure 3.133: Heat Disorders by Heat Index Level ...................................................................277 Figure 3.134: Annual Average Temperatures in the San Francisco Bay Area, 2000-2100 .......281 Figure 3.135: Beaufort Wind Scale ...........................................................................................282 Figure 3.136: Wind Zones in the US.........................................................................................283 Figure 3.137: Enhanced Fujita Scale........................................................................................287 Figure 3.138: Waterspout Formation ........................................................................................288 Figure 3.139: Tsunami Inundation Zones in the Marin County OA ...........................................291 Figure 3.140: Tsunami Inundation Zone – Inverness Area........................................................292 Figure 3.141: Tsunami Inundation Zone – Inverness................................................................293 Figure 3.142: Tsunami Inundation Zone – South of Inverness..................................................294 Figure 3.143: Tsunami Inundation Zone – Inverness Park and Point Reyes ............................295 Figure 3.144: Tsunami Inundation Zone – Reynolds and Marshall...........................................296 Figure 3.145: Tsunami Inundation Zone – McDonald and Blakes Landing...............................297 Figure 3.146: Tsunami Inundation Zone – South of Tomales....................................................298 Figure 3.147: Tsunami Inundation Zone – Dillon Beach Area...................................................299 Figure 3.148: Tsunami Inundation Zone – Dillon Beach ...........................................................300 Figure 3.149: Tsunami Inundation Zone – Bolinas Lagoon North.............................................300 Figure 3.150: Tsunami Inundation Zone – Bolinas Area ...........................................................301 Figure 3.151: Tsunami Inundation Zone – Bolinas Core...........................................................302 Figure 3.152: Tsunami Inundation Zone – Bolinas North..........................................................303 836
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Figure 3.153: Tsunami Inundation Zone – Stinson Beach Area................................................303 Figure 3.154: Tsunami Inundation Zone – Stinson Beach ........................................................304 Figure 3.155: Tsunami Inundation Zone – Muir Beach .............................................................305 Figure 3.156: Tsunami Inundation Zone – Tamalpais Valley South ..........................................306 Figure 3.157: Tsunami Inundation Zone – Tamalpais Valley North ...........................................307 Figure 3.158: Tsunami Inundation Zone – Marin City ...............................................................308 Figure 3.159: Tsunami Inundation Zone – Manzanita...............................................................308 Figure 3.160: Tsunami Inundation Zone – Strawberry South....................................................309 Figure 3.161: Tsunami Inundation Zone – Unincorporated Tiburon Peninsula .........................310 Figure 3.162: Tsunami Inundation Zone – Paradise Cay.......................................................... 311 Figure 3.163: North Marin Tsunami Inundation Zones..............................................................312 Figure 3.164: Santa Venetia Tsunami Inundation Zones ..........................................................313 Figure 3.165: Greenbrae Tsunami Inundation Zones................................................................314 Figure 3.166: Richardson Bay Tsunami Inundation Zones .......................................................315 Figure 3.167: Tomales Bay Tsunami Inundation Zones ............................................................316 Figure 3.168: Bolinas – Stinson Tsunami Inundation Zones.....................................................317 Figure 3.169: Federal, State and Local Responsibility Areas in the Marin County OA.............324 Figure 3.170: Fuel Model Map for the Marin County OA ..........................................................328 Figure 3.171: Wildfire Ignition Points in the Marin County OA..................................................331 Figure 3.172: WUI Boundary in the Marin County OA..............................................................332 Figure 3.173: Fire Hazard Severity Zones (FHSZ) in the Marin County OA.............................334 Figure 3.174: Marin County Wildfire Susceptibility to Critical Facilities.....................................335 Figure 3.175: Fire Hazard Severity Zones – Lagunitas, Forest Knolls, San Geronimo and Woodacre..................................................................................................................................336 Figure 3.176: Fire Hazard Severity Zones –Woodacre.............................................................336 Figure 3.177: Fire Hazard Severity Zones –Woodacre Area ....................................................337 Figure 3.178: Fire Hazard Severity Zones – Nicasio ................................................................338 Figure 3.179: Fire Hazard Severity Zones – Tocoloma.............................................................339 Figure 3.180: Fire Hazard Severity Zones – Olema .................................................................340 Figure 3.181: Fire Hazard Severity Zones – Point Reyes Station ............................................341 Figure 3.182: Fire Hazard Severity Zones – Inverness Park ....................................................342 Figure 3.183: Fire Hazard Severity Zones – Inverness ............................................................343 Figure 3.184: Fire Hazard Severity Zones – Inverness Area ....................................................344 Figure 3.185: Fire Hazard Severity Zones – Marconi/Marshall Area ........................................345 Figure 3.186: Fire Hazard Severity Zones – McDonald/Blakes Landing Area..........................346 Figure 3.187: Fire Hazard Severity Zones – Tomales...............................................................347 Figure 3.188: Fire Hazard Severity Zones – Dillon Beach........................................................348 Figure 3.189: Fire Hazard Severity Zones – Dogtown..............................................................349 Figure 3.190: Fire Hazard Severity Zones – Bolinas ................................................................350 Figure 3.191: Fire Hazard Severity Zones – Stinson Beach and Surrounding Area.................351 Figure 3.192: Fire Hazard Severity Zones – Stinson Beach.....................................................351 Figure 3.193: Fire Hazard Severity Zones – Muir Beach..........................................................352 Figure 3.194: Fire Hazard Severity Zones – Tamalpais Valley and Marin City .........................353 Figure 3.195: Fire Hazard Severity Zone – Unincorporated Tiburon Peninsula and Paradise Cay ..................................................................................................................................................354 Figure 3.196: Fire Hazard Severity Zones – San Quentin ........................................................355 Figure 3.197: Fire Hazard Severity Zones – Lucas Valley and Marinwood ..............................355 837
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Figure 3.198: Fire Hazard Severity Zone – Bel Marin Keys and Loma Verde ..........................356 Figure 3.199: Fire Hazard Severity Zone – San Antonio & Marin County Airport .....................357 Figure 3.200: Historic Wildfires in the Marin County OA 1919 - 1995.......................................358 Figure 3.201: Historic Wildfires in the Marin County OA 1973 - 2020.......................................359 Figure 3.202: 1995 Vision Fire..................................................................................................360 Figure 3.203: Population Density, Flame Length, and Rate of Spread for the Average Fire Season in the Marin County OA ...............................................................................................365 Figure 3.204: Areas of Concern for the Average Fire Season in the Marin County OA............366 Figure 3.205: Areas of Concern for the Extreme Fire Season in the Marin County OA............367 Figure 3.206: WUI Boundary and Population Density in the Marin County OA ........................368 Figure 3.207: Trends in the Annual Number of Large Wildfires in the United States................372 Figure 3.208: Air Quality Index Concern Levels........................................................................376 Figure 3.209: Marin County OA Critical Infrastructure ..............................................................377 Figure 3.210: Largest Oil Spills Affecting U.S. Waters 1969-2017............................................385 Figure 3.211: Marin County Covid-19 Hospitalizations .............................................................391 Figure 3.212: Marin County Covid-19 Hospitalizations by Demographics................................391 Figure 3.213: Marin County Highways......................................................................................393 Figure 3.214: SMART Commuter and Freight Line...................................................................396 TABLES
Table 1.1: Marin County Population Changes 1860-2020 ..........................................................26 Table 1.2: Marin County Estimated Jurisdictional Population .....................................................26 Table 1.3: Marin County Estimated Jurisdictional Population Change 2010-2020 .....................27 Table 1.4: Marin County Population Age by Gender 2020 ..........................................................28 Table 1.5: Marin County Population by Race or Ethnicity ...........................................................28 Table 1.6: Marin County Housing Stock......................................................................................29 Table 1.7: Marin County Jurisdictional Housing Stock ................................................................31 Table 1.8: Historic Sites in Marin County ....................................................................................53 Table 1.9: NRI Risk Components and Factors............................................................................56 Table 1.10: NRI Hazards and Marin County OA MJHMP Hazards .............................................57 Table 1.11: NRI Hazard Type Risk Index for Marin County.........................................................59 Table 1.12: NRI Highest-Risk Communities in Marin County......................................................60 Table 1.13: Marin County Civilian Employed Population 16 Years and Over..............................67 Table 1.14: Marin County OA MJHMP Participants 2018 and 2023............................................69 Table 2.1: 2023 Marin OA MJHMP Participating Jurisdictions ....................................................76 Table 2.2: Marin County OA MJHMP Steering Committee Members..........................................77 Table 2.3: Marin County OA MJHMP Preparative Consulting Planning Team Members ............78 Table 2.4: Marin County OA MJHMP Planning Team Members..................................................82 Table 2.5: Marin County OA MJHMP Planning Meetings............................................................86 Table 3.1: Marin County OA MJHMP Hazard Identification and Comparison ...........................101 Table 3.2: Marin County OA MJHMP Other Hazards Profiled...................................................102 Table 3.3: State and Federal Declared Disasters in Marin County ...........................................104 Table 3.4: Marin County Hazard Risk Assessment ...................................................................108 Table 3.5: Hazard Magnitude and Severity Scale .....................................................................109 838
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Table 3.6: Marin County Hazard Risk Assessment – Top Hazards Scored............................... 110 Table 3.7: Hazard Ranked Dams in Marin County with Potential to Impact to the OA..............123 Table 3.8: Marin County OA Hazard Risk Assessment – Dam Failure......................................153 Table 3.9: Marin County OA Hazard Risk Assessment – Debris Flow ......................................173 Table 3.10: Marin County OA Hazard Risk Assessment – Drought ..........................................183 Table 3.11: Marin County OA Hazard Risk Assessment – Earthquake.....................................193 Table 3.12: Marin County OA Hazard Risk Assessment – Flooding .........................................236 Table 3.13: Marin County OA Hazard Risk Assessment – Land Subsidence ...........................246 Table 3.14: Marin County OA Hazard Risk Assessment – Levee Failure .................................263 Table 3.15: Marin County OA Hazard Risk Assessment - Sea Level Rise................................270 Table 3.16: Marin County OA Hazard Risk Assessment – Severe Weather, Extreme Heat .....279 Table 3.17: Marin County OA Hazard Risk Assessment – Severe Weather; Wind...................286 Table 3.18: Tornado Activity in the Marin County OA................................................................288 Table 3.19: Marin County OA Hazard Risk Assessment - Tsunami...........................................319 Table 3.20: Marin County OA Hazard Risk Assessment – Wildfire ...........................................363 Table 4.1: Unincorporated Marin County Future Growth Areas ................................................401 Table 4.2: Marin County Legal and Regulatory Capabilities .....................................................406 Table 4.3: Marin County Goals and Policies .............................................................................407 Table 4.4: Marin County Goals and Policies ............................................................................ 411 Table 4.5: Marin County Fiscal Capabilities .............................................................................413 Table 4.6: Marin County Community Outreach .........................................................................414 Table 4.7: Participation in the National Flood Insurance Program (NFIP) ................................420 Table 4.8: Status of Previous Hazard Mitigation Actions...........................................................430 Table 4.9: Marin County Current Hazard Mitigation Actions .....................................................462 839
2023 Marin County Operational Area
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478
ACRONYMS
Acronym Definition
ABAG Association Bay Area of Governments
AQI Air Quality Index
ARP Address Resolution Protocol
ASL American Sign Language
ATSDR Agency for Toxic Substances and Disease Registry
BAAQMD Bay Area Air Quality Management District
BCDC Bay Conservation and Development Commission
BCPUD Bolinas Community Public Utility District
BRIC Building Resilient Infrastructure and Communities
CA California
CAL FIRE California Department of Forestry and Fire Protection Cal OES California Office of Emergency Services
CAP Climate Action Plan
CASPER Community Assessment for Public Health Emergency Response - California Department of Public Health
CDA Community Development Agency
CDC Centers for Disease Control and Prevention
CDI Certified Deaf Interpreter
CEQA California Environmental Quality Act
CGS California Geological Survey
CIP Capital Improvement Plan
CMFD Central Marin Fire District
CNRA California Natural Resource Agency
CNRA California Natural Resource Agency
CNRA California Natural Resource Agency
CO Carbon Monoxide
COVID-19 Coronavirus Disease 2019
COYL Coyote Creek Left Bank Levee
CPUC California Public Utilities Commission
CRF Community Risk Factor
CRI Community Resilience Index
CRS Community Rating System
840
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479
CRT Community Response Team
CSA County Service Area
C-SMART Sea-level Marin Adaption Response Team
CWPP Community Wildfire Protection Plan
DDoS Distributed Denial of Service
DMA Disaster Mitigation Act
DNS Domain Name System
DOF California Department of Finance
DoS Denial-of-Service
DPW Department of Public Works
DR Disaster Relief
DSOD Division of Safety of Dams - California Department of Water Resources DWR California Department of Water Resources
EAL Expected Annual Loss
EAS Emergency Alert System
EOC Emergency Operation Center
EOP Emergency Operations Plan
EPA Environmental Protection Agency
ESHA Environmentally Sensitive Habitat Areas
FD Fire Department
FEMA Federal Emergency Management Agency
FHSV Fire Hazard Severity Zones
FIRM Flood Insurance Rate Maps
FMA Flood Mitigation Assistance
FMP Flood Mitigation Plan
FPA Floodplain Administrator
FRA Federal Responsibility Areas
FY Fiscal Year
GGNRA Golden Gate National Recreation Area
GGNRA Golden Gate National Recreation Area
GIS Geographic Information System
Gov Government
GPAC General Plan Advisory Committee
H2S Hydrogen Sulfide
841
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480
HFHSZ High Fire Severity Zone
HIRA Hazard Identification and Risk Assessment
HIV/AIDS Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome HLR Historic Loss Ratio
HMGP Hazard Mitigation Grant Program
IoT Internet of Things
IP Intellectual Property
IPAWS Integrated Public Alert and Warning System
ISEPA Identified Site Emergency Planning Application
LCP Local Coastal Program
LGVSD Las Gallinas Valley Sanitary District
LHMP Local Hazard Mitigation Plan
LRA Local Responsibility Areas
LRAD Long-Range Acoustic Device
LSAC Levee Safety Action Classification
Marin IJ Marin Independent Journal
MCEP Marin Climate Energy Partnership
MCFD Marin County Fire Department
MCOSD Marin County Open Space District
MCPIO Marin County Public Information Officers
MCSTOPP Marin County Stormwater Pollution Prevention Program MERA Marin Emergency Radio Authority
MERS Middle Eastern Respiratory Syndrome
MFHSZ Moderate Fire Severity Zone
MHOAC Medical/Health Operational Area Coordinator
MJHMP Multi-Jurisdictional Hazard Mitigation Plan
MMI Modified Mercalli Intensity
MMWD Marin Municipal Water District
MRZ Mineral Resource Zones
MV2040 Mill Valley General Plan 2040
Mw Scale Moment Magnitude Scale
MWPA Marin Wildfire Prevention Authority
NASA National Aeronautics and Space Administration
NCDC National Climatic Data Center
842
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481
NFDRS National Fire Danger Rating System
NFIP National Flood Insurance Program
NID National Inventory of Dams
NIH National Institute for Health
NMWD North Marin Water District
NPR Northwestern Pacific Railroad
NR National Register of Historic Places
NRI National Risk Index
NWS National Weather Service
O3 Ozone
OA Operational Area
OEM Office of Emergency Management
OHP Office of Historic Preservation
OWTA On-Site Wastewater Treatment Systems
PD Police Department
PG&E Pacific Gas & Electric
PM10 Particulate Matter Less Than 10 Microns In Aerodynamic Diameter PSPS Public Safety Power shutoffs
PtH Pass the hash
PW Public Works
RAWS Remote Automated Weather Stations
RCD Resource Conservation District
RHNA Regional Housing Needs Assessment
SASM Sewerage Agency of Southern Marin
SFBRA San Francisco Bay Restoration Authority
SFHA Special Flood Hazard Area
SFHA Special Flood Hazard Areas - FEMA
SFHA Special Flood Hazard Area
SHMP State Hazard Mitigation Plan
SMART Sonoma Marin Area Rail Transit
SMFD Southern Marin Fire District
SOX Sulfur Oxides
SQL Structured Query Language
SRA State Responsibility Areas
843
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482
SVI Social Vulnerability Index
TAM Transportation Authority of Marin
UCERF2 Uniform California Earthquake Rupture Forecast, Version 2 UCERF3 Uniform California Earthquake Rupture Forecast, Version 3 USACE U.S. Army Corps of Engineers
USGS United States Geological Survey
VHFHSV Very High Fire Severity Zone
WC/ATWC West Coast/Alaska Tsunami Warning Center
WHO World Health Organization
WUI Wildland Urban Interface
XSS Cross-Site Scripting
844
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483
APPENDIX A: ADOPTION LETTERS
845
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846
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847
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848
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849
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850
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489
851
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852
2023 Marin County Operational Area
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491
853
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854
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855
2023 Marin County Operational Area
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856
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495
857
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496
858
2023 Marin County Operational Area
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497
859
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498
860
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499
861
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
500
862
2023 Marin County Operational Area
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501
863
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502
864
2023 Marin County Operational Area
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503
865
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504
866
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
505
867
2023 Marin County Operational Area
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506
868
2023 Marin County Operational Area
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507
869
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
508
870
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
509
871
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
510
872
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
511
873
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
512
874
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
513
APPENDIX B: DOCUMENTATION OF THE PLANNING PROCESS
875
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
514
876
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
515
877
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
516
878
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
517
879
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
518
880
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
519
881
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
520
882
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
521
883
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
522
884
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
523
885
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
524
886
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
525
887
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
526
888
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
527
889
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
528
890
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
529
891
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
530
892
Marin County Multi-Jurisdictional Hazard Mitigation Plan Survey 1 / 19
Q1 How concerned are you about the following Hazards in your community?
Answered: 293 Skipped: 0
Climate Change
Dam Failure
Drought
Earthquake
893
Marin County Multi-Jurisdictional Hazard Mitigation Plan Survey 2 / 19
Flooding
Landslides/Eros
ion/Debris...
Land
Subsidence...
Levee Failure
Sea Level Rise
Severe Weather
- Extreme Heat
894
Marin County Multi-Jurisdictional Hazard Mitigation Plan Survey 3 / 19
0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
Not Concer… Somewhat … Moderately… Very Conce…
Severe Weather
- Wind, Hail...
Tsunami
Wildfire
895
Marin County Multi-Jurisdictional Hazard Mitigation Plan Survey 4 / 19
4.10%
12 10.24%
30 20.82%
61 64.85%
190 293
53.92%
158
25.60%
75 13.99%
41 6.48%
19 293
4.44%
13 11.26%
33 27.65%
81 56.66%
166 293
1.71%
5 22.87%
67 37.20%
109
38.23%
112 293
11.26%
33 24.57%
72 24.91%
73 39.25%
115 293
10.24%
30 30.03%
88 33.11%
97 26.62%
78 293
39.93%
117
35.15%
103
16.04%
47 8.87%
26 293
48.46%
142
25.26%
74 13.65%
40 12.63%
37 293
11.60%
34 23.21%
68 30.03%
88 35.15%
103 293
8.87%
26 21.84%
64 34.81%
102
34.47%
101 293
8.87%
26 27.30%
80 33.79%
99 30.03%
88 293
40.96%
120
34.47%
101
17.41%
51 7.17%
21 293
3.41%
10 11.95%
35 22.53%
66 62.12%
182 293
NOT
CONCERNED
SOMEWHAT
CONCERNED
MODERATELY
CONCERNED
VERY
CONCERNED
TOTAL
Climate Change
Dam Failure
Drought
Earthquake
Flooding
Landslides/Erosion/Debris
Flows
Land Subsidence (Sinkhole)
Levee Failure
Sea Level Rise
Severe Weather - Extreme
Heat
Severe Weather - Wind, Hail,
Lighting
Tsunami
Wildfire
896
Marin County Multi-Jurisdictional Hazard Mitigation Plan Survey 5 / 19
Q2 What is the best way for you to receive information about how to make your home and the people in your home safer from natural disasters? Answered: 293 Skipped: 0
897
Marin County Multi-Jurisdictional Hazard Mitigation Plan Survey 6 / 19
0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
Television
Radio
Newspaper
Cellphone Call
Cellphone Text
Home Phone
(Landline)
Social Media -
Facebook,...
County, City,
or Official...
Utility bill
Mail - Letter
or postcard
School/ School
District
Church/
Religious...
Community
Group or Clubs
Chamber of
Commerce
Outdoor
Advertising ...
Fire Station
Postings
Public Meetings
Other (please
specify)
898
Marin County Multi-Jurisdictional Hazard Mitigation Plan Survey 7 / 19
16.04% 47
19.45% 57
27.65% 81
8.19% 24
51.19% 150
9.90% 29
23.89% 70
38.57% 113
15.02% 44
41.30% 121
3.41% 10
1.02% 3
10.58% 31
1.71% 5
9.90% 29
6.14% 18
24.23% 71
17.06% 50
Total Respondents: 293
ANSWER CHOICES RESPONSES
Television
Radio
Newspaper
Cellphone Call
Cellphone Text
Home Phone (Landline)
Social Media - Facebook, Twitter, Nextdoor
County, City, or Official Government website
Utility bill
Mail - Letter or postcard
School/ School District
Church/ Religious Institution
Community Group or Clubs
Chamber of Commerce
Outdoor Advertising - Billboards, Sandwich Boards, Bulletin Boards Fire Station Postings
Public Meetings
Other (please specify)
899
Marin County Multi-Jurisdictional Hazard Mitigation Plan Survey 8 / 19
1.37% 4
19.45% 57
31.40% 92
47.78% 140
Q3 How concerned are you that a natural disaster could threaten your home or place of residence?
Answered: 293 Skipped: 0
TOTAL 293
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Not at all Somewhat Moderately Very Much
ANSWER CHOICES RESPONSES
Not at all
Somewhat
Moderately
Very Much
900
Marin County Multi-Jurisdictional Hazard Mitigation Plan Survey 9 / 19
Q4 In the following List, Please check those activities that you or someone in your household, Completed, Plan to do in the near future, Have not done, or are Unable to do. (Please check one answer per activity).
Answered: 293 Skipped: 0
76.03%
222
9.59%
28 9.93%
29 1.03%
3 3.42%
10 292 1.46
67.47%
195
19.03%
55 9.69%
28 3.11%
9 0.69%
2 289 1.51
48.28%
140
32.76%
95 17.24%
50 1.38%
4 0.34%
1 290 1.73
62.12%
182
25.94%
76 10.92%
32 0.00%
0 1.02%
3 293 1.52
29.27%
84 9.41%
27 52.26%
150
4.88%
14 4.18%
12 287 2.45
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Completed. Planning to… Have not d… Unable to do.
I do not hav…
Attended
meetings or
received
written...
Talked with
family
members about
what to do...
Developed a
“Household/Fa
mily
Emergency...
Prepared a
“Disaster
Supply Kit”
(extra foo...
In the last
year, has
someone in
your...
COMPLETED. PLANNING
TO DO.
HAVE
NOT
DONE.
UNABLE
TO DO.
I DO NOT
HAVE
ENOUGH
INFORMATION
TO
COMPLETE
THIS TASK.
TOTAL WEIGHTED
AVERAGE
Attended meetings or received
written information on natural
disasters or emergency
preparedness.
Talked with family members
about what to do in case of a
disaster or emergency.
Developed a “Household/Family
Emergency Plan” in order to
decide what everyone would do
in the event of a disaster.
Prepared a “Disaster Supply Kit”
(extra food, water, batteries,
medications, first aid, and other
emergency supplies).
In the last year, has someone in
your household been trained in
First Aid or Cardio-Pulmonary
Resuscitation (CPR).
901
Marin County Multi-Jurisdictional Hazard Mitigation Plan Survey 10 / 19
Q5 Natural disasters can have a significant impact on a community, but planning for these events can help lessen the impact. The following statements will help us determine community priorities in planning for these hazards. Please tell us how important each one is to you? Answered: 293 Skipped: 0
61.94%
179
25.61%
74 8.30%
24 2.77%
8 1.38%
4 289 1.56
94.54%
277
4.78%
14 0.00%
0 0.34%
1 0.34%
1 293 1.07
48.12%
141
38.57%
113
8.53%
25 2.73%
8 2.05%
6 293 1.72
20.00%
58 46.90%
136
19.31%
56 9.31%
27 4.48%
13 290 2.31
78.35%
228
18.56%
54 2.75%
8 0.00%
0 0.34%
1 291 1.25
63.57%
185
23.37%
68 7.22%
21 3.44%
10 2.41%
7 291 1.58
66.55%
195
24.57%
72 6.14%
18 1.71%
5 1.02%
3 293 1.46
64.48%
187
24.48%
71 7.59%
22 2.07%
6 1.38%
4 290 1.51
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Very Import… Somewhat I… Neutral Not As Imp…
Not Import…
Protecti
ng
private
property
Protecti
ng
critical
facil...
Protecti
ng
natural
envir...
Protecti
ng
historic
al /...
Protecti
ng and
reducing
damag...
Preventi
ng
developm
ent i...
Promotin
g
cooperat
ion...
Strength
ening
emergenc
y...
VERY
IMPORTANT
SOMEWHAT
IMPORTANT
NEUTRAL NOT AS
IMPORTANT
NOT
IMPORTANT
TOTAL WEIGHTED
AVERAGE
Protecting private property
Protecting critical facilities
(hospitals, transportation
networks, fire stations)
Protecting natural
environment
Protecting historical / cultural
landmarks
Protecting and reducing
damage to utilities
Preventing development in
hazardous areas
Promoting cooperation
among public agencies,
citizens, non-profit
organizations and businesses
Strengthening emergency
services (police, fire,
ambulance)
902
Marin County Multi-Jurisdictional Hazard Mitigation Plan Survey 11 / 19
Q6 Please provide your zip code
Answered: 290 Skipped: 3
94901
94903
94904
94912
94913
94914
94915
94920
94924
94925
94929
94930
94933
94937
94938
94939
94940
94941
94942
903
Marin County Multi-Jurisdictional Hazard Mitigation Plan Survey 12 / 19
94942
94945
94946
94947
94948
94949
94950
94957
94960
94963
94964
94965
94966
94970
94971
94973
94974
94976
94977
94978
94979
Other (please
904
Marin County Multi-Jurisdictional Hazard Mitigation Plan Survey 13 / 19
0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
Other (please
specify)
905
Marin County Multi-Jurisdictional Hazard Mitigation Plan Survey 14 / 19
6.21% 18
10.34% 30
3.10% 9
0.00% 0
0.00% 0
0.00% 0
0.00% 0
1.38% 4
0.69% 2
3.79% 11
0.00% 0
3.79% 11
0.34% 1
7.59% 22
0.69% 2
2.07% 6
2.76% 8
13.45% 39
0.00% 0
1.38% 4
1.38% 4
4.48% 13
0.00% 0
5.86% 17
4.83% 14
2.07% 6
5.52% 16
0.69% 2
0.00% 0
4.83% 14
0.00% 0
1.72% 5
ANSWER CHOICES RESPONSES
94901
94903
94904
94912
94913
94914
94915
94920
94924
94925
94929
94930
94933
94937
94938
94939
94940
94941
94942
94945
94946
94947
94948
94949
94950
94957
94960
94963
94964
94965
94966
94970
906
Marin County Multi-Jurisdictional Hazard Mitigation Plan Survey 15 / 19
1.03% 3
0.69% 2
0.00% 0
0.00% 0
0.00% 0
0.00% 0
0.00% 0
9.31% 27
TOTAL 290
94971
94973
94974
94976
94977
94978
94979
Other (please specify)
907
Marin County Multi-Jurisdictional Hazard Mitigation Plan Survey 16 / 19
Q7 Your City, Town, or Community Name
Answered: 290 Skipped: 3
908
Marin County Multi-Jurisdictional Hazard Mitigation Plan Survey 17 / 19
85.37% 245
14.63% 42
Q8 Do you live within the limits of the specific City or Town listed in question #7?
Answered: 287 Skipped: 6
TOTAL 287
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Yes No
ANSWER CHOICES RESPONSES
Yes
No
909
Marin County Multi-Jurisdictional Hazard Mitigation Plan Survey 18 / 19
1.03% 3
84.14% 244
14.14% 41
0.69% 2
Q9 Do you own, rent or share a home?
Answered: 290 Skipped: 3
TOTAL 290
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
None of the
above
Own Rent Shared Housing
ANSWER CHOICES RESPONSES
None of the above
Own
Rent
Shared Housing
910
Marin County Multi-Jurisdictional Hazard Mitigation Plan Survey 19 / 19
99.66% 291
0.34% 1
Q10 Do you have internet access at your home?
Answered: 292 Skipped: 1
TOTAL 292
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Yes No
ANSWER CHOICES RESPONSES
Yes
No
911
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
551
Public Outreach Survey Spanish
912
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
552
913
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
553
914
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
554
915
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
555
916
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
556
917
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
557
918
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
558
919
11. TOWN OF SAN ANSELMO
COMMUNITY PROFILE
MARIN COUNTY MULTI-JURISDICTIONAL
HAZARD MITIGATION PLAN
2023
920
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TOWN OF SAN ANSELMO COMMUNITY PROFILE
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TOWN OF SAN ANSELMO COMMUNITY PROFILE
ACKNOWLEDGEMENTS
The Town of San Anselmo and Preparative Consulting would like to thank those collaborators and partners who participated in the planning and development of this document.
The official Marin County Operational Area (OA) Multi-Jurisdictional Hazard Mitigation Plan (MJHMP) Steering Committee provided the oversight and dedication to this project that was required and without their commitment; this project would not be possible.
As with any working plan, this document represents planning strategies and guidance as understood as of the date of this plan’s release. This plan identifies natural hazards and risks and identifies the hazard mitigation strategy to reduce vulnerability and make the communities of the Town of San Anselmo more disaster resistant and sustainable. 922
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11-5
TOWN OF SAN ANSELMO COMMUNITY PROFILE
TABLE OF CONTENTS
11. Town of San Anselmo Community Profile............................................................... 11-1 Acknowledgements......................................................................................................... 11-3 Table of Contents ............................................................................................................ 11-5 Section 1.0: Introduction................................................................................................. 11-7
1.1 Introduction ............................................................................................................ 11-7
1.2 Planning Process ................................................................................................... 11-7
1.2.1 Steering Committee Members (Jurisdictional Representatives)....................... 11-8
1.2.2 Steering Committee Planning Process............................................................. 11-9
1.2.3 Coordination with stakeholders and agencies................................................... 11-9
1.2.4 Public Engagement ........................................................................................ 11-16
1.3 Overview and History ........................................................................................... 11-23
1.4 Government ......................................................................................................... 11-26
1.5 Weather and Climate ........................................................................................... 11-26
1.6 Demographics...................................................................................................... 11-27
1.7 Social Vulnerability and Risk ................................................................................ 11-31
1.8 Economy and Tax Base ....................................................................................... 11-35
1.9 Critical Facilities ................................................................................................... 11-36
1.10 Historical Properties ........................................................................................... 11-38 Section 2.0: Hazard Identification and Risk Assessment........................................... 11-39
2.1 Climate Change ................................................................................................... 11-41
2.2 Hazards ............................................................................................................... 11-48
2.2.1 Dam Failure................................................................................................... 11-49
2.2.2 Debris Flows.................................................................................................. 11-53
2.2.3 Drought.......................................................................................................... 11-59
2.2.4 Earthquake.................................................................................................... 11-61
2.2.5 Flooding......................................................................................................... 11-67
2.2.6 Land Subsidence........................................................................................... 11-76
2.2.8 Severe Weather – Extreme Heat ................................................................... 11-78
2.2.9 Severe Weather – High Wind & & Tornado.................................................... 11-80
2.2.10 Wildfire ........................................................................................................ 11-83 Section 3.0: Mitigation Strategy ................................................................................... 11-96
3.1 Changes in Development..................................................................................... 11-96
3.2 Capability Assessment......................................................................................... 11-97 924
2023 Marin County Operational Area
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11-6
TOWN OF SAN ANSELMO COMMUNITY PROFILE
3.2.1 Regulatory Capabilities.................................................................................. 11-98
3.2.2 Administrative and Technical Capabilities.................................................... 11-106
3.2.3 Fiscal Capabilities........................................................................................ 11-108
3.2.4 Community Outreach................................................................................... 11-109
3.2.5 Participation in the National Flood Insurance Program ................................ 11-110
3.3 Mitigation Goals ................................................................................................. 11-114
3.4 Status of Previous Mitigation Actions ................................................................. 11-116
3.5 Hazard Mitigation Actions................................................................................... 11-119
3.6 Progress in Local Mitigation Efforts .................................................................... 11-124
3.7 Project Implementation ...................................................................................... 11-124
3.8 Future Development Trends............................................................................... 11-125 Section 4.0: Plan Review, Evaluation, and Implementation...................................... 11-127
4.1 Plan Adoption..................................................................................................... 11-127
4.2 Plan Monitoring .................................................................................................. 11-127
4.3 Plan Evaluation .................................................................................................. 11-128
4.4 Plan Update ....................................................................................................... 11-128 Figures and Tables...................................................................................................... 11-130 Acronyms/Abbreviations ............................................................................................ 11-132 925
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
11-7
TOWN OF SAN ANSELMO COMMUNITY PROFILE
SECTION 1.0: INTRODUCTION
1.1 INTRODUCTION
The Town of San Anselmo Community Profile has been prepared in conjunction with the Marin County Operational Area (OA) Multi-Jurisdictional Hazard Mitigation Plan (MJHMP), establishing an inter-jurisdictional process for the development and implementation of effective hazard mitigation strategies in association with identified hazards that pose real or potential threats to the Town of San Anselmo.
1.2 PLANNING PROCESS
The majority of the Marin County Operational Area (OA) is unincorporated sparsely populated rural and protected lands. Most of the 262,000 county population, both incorporated and unincorporated, is concentrated in the Eastern portion of the county. There are a total of 11 incorporated jurisdictions within Marin County. The Marin County OA MJHMP Steering Committee and broader Planning Team approached the development of the Marin County OA MJHMP and the associated jurisdictional and district profiles from a coordinated and collaborative planning and public engagement unity of effort.
The Steering Committee felt a unified effort, led by the County Office of Emergency Management (OEM), would be the most effective approach for this planning process. This approach allowed the small jurisdictions and districts with limited staffing and resources to take advantage of the combined efforts of the County and other jurisdictions to reach a broader segment of each of their own populations and do so in a way to ensure greater equity and inclusion of the public in this planning process. Extensive and coordinated public outreach was done involving all participating jurisdictions and districts with an eye towards equity, inclusion, openness, accessibility, and ensuring they meet the population where they live, work, or recreate to provide the public convenience of access and ease of participation in this planning process.
The Marin County OA is very different from most California Counties in that the populated portion of the County where the jurisdictions and district’s planning areas are located has the same climate, similar topography, and are exposed to many of the same hazards. Only three jurisdictions, Larkspur, Ross, and San Anselmo, are not coastal jurisdictions and are not impacted by Tsunami or Sea Level Rise.
This unity of effort approach allowed the Steering Committee to establish a more robust Planning Team representing local, countywide, regional, state, and federal stakeholders servicing the Marin County OA planning area. These stakeholders were in a unique position to provide informed and specific information and recommendations on hazard mitigation goals and actions, as well as population needs and social vulnerability for each of the jurisdictional and district planning areas. This united effort allowed the planning team to attend fewer meetings than they would have been required to attend if they were required to attend separate meetings for each participating jurisdiction and district. The reduced number of meetings allowed the planning team the opportunity and time to provide more detailed and thoughtful contributions to the planning effort.
In addition to providing representation on the coordinated Marin County OA MJHMP Steering Committee, the Town of San Anselmo involved additional internal planning team to support the broader planning process. The Town of San Anselmo jurisdictional representatives for the 926
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
11-8
TOWN OF SAN ANSELMO COMMUNITY PROFILE
coordinated Marin County OA MJHMPs Steering Committee and the Planning Team Members are represented below.
1.2.1 STEERING COMMITTEE MEMBERS (JURISDICTIONAL REPRESENTATIVES) Primary Point of Contact Alternate Point of Contact
Sean Condry, Director of Public Works Erica Freeman, Building Official Telephone: (415) 258-4676 Telephone: (415) 523-4984
E-mail address:
[email protected]
E-mail address:
[email protected]
This annex was developed by the primary point of contact with assistance from the members of the local mitigation planning team listed in Table 1 and Table 2.
Table 1: Local Hazard Mitigation Planning Team Members
Jurisdiction Name Title/
Department Phone Email
San
Anselmo Sean Condry
Public Works
& Building
Director
415-258-
4676
[email protected]
g
San
Anselmo Erica Freeman Building Official
415-523-
4984
efreeman@townofsananselmo.
org
San
Anselmo Scott Schneider Asst. PW Director
415-258-
4653
sschneider@townofsananselmo.
org
Central
Marin Fire
District
Matt Cobb Battalion
Chief/Fire
415-927-
5077 [email protected]
Central
Marin Fire
District
Ezra Colman Battalion
Chief/Fire
415-927-
5077 [email protected]
Table 249: Local Hazard Mitigation Planning Team Members This 2023 Marin County Operational Area (OA) MJHMP is a comprehensive update of the 2018 Marin County OA MJHMP. The planning area and participating jurisdictions and organizations were defined to consist of unincorporated County of Marin, five special districts, and the eleven incorporated jurisdictions to include the Town of San Anselmo. All participating jurisdictions are within the geographical boundary of the Marin County OA and have jurisdictional authority within this planning area.
The Steering Committee led the planning process based on the contribution and input from the whole community stakeholders who identified the community’s concerns, values, and priorities.
The Steering Committee met and reviewed the mitigation recommendations and strategies identified within this plan. Each participating local jurisdiction established a mechanism for the development and implementation of jurisdictional mitigation projects, as identified within this plan and associated locally specific supporting documents. As deemed necessary and appropriate, participating jurisdictions will organize local mitigation groups to facilitate and administer internal activities.
The Steering Committee assisted with the planning process in the following ways:
• Attending and participating in the Steering Committee meetings. 927
2023 Marin County Operational Area
Multi-Jurisdictional Hazard Mitigation Plan
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TOWN OF SAN ANSELMO COMMUNITY PROFILE
• Identification of potential mitigation actions.
• Updating the status of mitigation actions from the 2018 Marin County OA MJHMP. • Collecting and providing other requested data (as available). • Making decisions on plan process and content.
• Reviewing and providing comments on plan drafts; including annexes. • Informing the public, local officials, and other interested stakeholders about the planning process and providing opportunity for them to be involved and provide comment.
• Coordinating, and participating in the public input process. • Coordinating the formal adoption of the plan by the governing boards.
1.2.2 STEERING COMMITTEE PLANNING PROCESS
The Steering Committee met monthly to develop the plan. Email notifications were sent out to each Steering Committee member to solicit their participation in the Steering Committee meetings. The meetings were conducted using a Zoom platform videoconferencing. Meeting attendees signed in using the chat feature to record their attendance.
The Steering Committee agreed to make and pass plan-based general policy recommendations by a vote of a simple majority of those members present. The Steering Committee will also seek input on future hazard mitigation programs and strategies from the mitigation planning team by focusing on the following:
• Identify new hazard mitigation strategies to be pursued on a state and regional basis and review the progress and implementation of those programs already identified. • Review the progress of the Hazard Mitigation program and bring forth community input on new strategies.
• Coordinate with and support the efforts of the Marin County OEM to promote and identify resources and grant money for implementation of recommended hazard mitigation Strategies within local jurisdictions and participating public agencies.
During the planning process, the Steering Committee communicated through videoconferencing, face-to-face meetings, email, telephone conversations, and through the County website. The County website included information for all stakeholders on the MJHMP update process. Hannah Tarling of the Marin County OEM and Preparative Consulting established a Microsoft 365 SharePoint folder which allowed the Steering Committee members and Marin OEM and Preparative Consulting to share planning documents and provide a format for the planning partners to submit completed documents and access other planning related documents and forms. Draft documents were also posted on this platform and the Marin County OEM website so that the Steering Committee members and the public could easily access and review them.
1.2.3 COORDINATION WITH STAKEHOLDERS AND AGENCIES
Opportunities for involvement in the planning process must be provided to neighboring communities, local and regional agencies involved in hazard mitigation, agencies with authority to regulate development, businesses, academia, and other private and nonprofit interests (44 CFR, Section 201.6(b)(2)).
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Committee reached out to the following Local and Regional Agencies involved in hazard mitigation activities to invite them to participate in this planning process as a member of the Planning Team. These individuals work with Marin County and the Town of San Anselmo communities and could provide subject matter expertise and relevant information to the planning process regarding the community history, hazard risk, vulnerability, and impact, mitigations efforts, community needs, demographics, and social vulnerability, economic concerns, ecology, and other community services and needs.
The Marin County and Town of San Anselmo Steering also determined that data collection, risk assessment analyses, mitigation strategy development, and plan approval would be greatly enhanced by inviting other local, state and federal agencies and organizations to participate in the process. Based on their involvement in hazard mitigation planning, their landowner status in the County, the Town of San Anselmo and/or their interest as a neighboring jurisdiction, representatives from the following groups were invited to participate on the Planning Team:
Eighty-five planning partners participated in this update, as listed in Table 2.
Table 2: 2023 MJHMP Planning Team Members
No. Agency Point of Contact Title
1 Belvedere Laurie Nilsen Emergency Svs, Coord.
2 Belvedere Rebecca Markwick Planning Director
3 Belvedere Samie Malakiman Associate Planner
4 Bolinas Com. PUD Jennifer Blackman General Manager
5 Bolinas Fire Protection
Dist.
Stephen Marcotte Asst. Fire Chief
6 Central Marin Fire District Matt Cobb Battalion Chief/Fire 7 Central Marin Fire District Ezra Colman Battalion Chief/Fire 8 Central Marin Fire District Rubin Martin Fire Chief
9 Corte Madera RJ Suokko Director of Public Works
10 Corte Madera Chris Good Senior Civil Engineer
11 Sanitary District No. 2 RJ Suokko Public Works Director 12 Fairfax Loren Umbertis Public Works Director
13 Fairfax Mark Lockaby Building Official
14 Larkspur Dan Schwarz City Manager
15 Larkspur Julian Skinner Public Works Director/ City Engineer 16 Larkspur Robert Quinn Public Works Superintendent
17 Las Gallinas Valley
Sanitary District Dale McDonald Administrative Services Mgr. 18 Las Gallinas Valley
Sanitary District Greg Pease Safety Manager
19 County of Marin Steven Torrence OEM Director
20 County of Marin Hannah Tarling Emergency Management Coordinator 21 County of Marin Chris Reilly OEM Project Manager
22 County of Marin Woody BakerCohn Senior Emergency Management Coordinator 23 County of Marin Leslie Lacko Community Development Agency 24 County of Marin Hannah Lee Senior Civil Engineer
25 County of Marin Felix Meneau Project Mgr./ FCWCD
26 County of Marin Julia Elkin Department of Public Works 929
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Table 2: 2023 MJHMP Planning Team Members
No. Agency Point of Contact Title
27 County of Marin Beb Skye Department of Public Works
28 County of Marin Scott Alber Battalion Chief, Marin County Fire Dept. 29 County of Marin Lisa Santora Deputy Public Health Officer, Marin Health & Human Services
30 County of Marin Koblick, Kathleen Marin Health & Human Services 31 County of Marin Amber Davis Public Health Preparedness 32 Mill Valley Patrick Kelly Department of Public Works 33 Mill Valley Ahmed A Aly Project Manager
34 Mill Valley Jared Barrilleaux Deputy Director of Engineering 35 Mill Valley Daisy Allen Senior Planner
36 Southern Marin Fire
District Tom Welch Deputy Chief/South Marin Fire Dist.
37 Southern Marin Fire
District Marshall Nau Fire Marshall/South Marin Fire Dist. 38 North Marin Water District Eric Miller Asst. General Manager 39 North Marin Water District Tim Fuette Senior Engineer 40 Novato David Dammuller Engineering Services Mgr.
41 Novato Dave Jeffries Consultant/JPSC
42 Ross Richard Simonitch Public Works Director
43 San Anselmo Sean Condry Public Works & Building Director 44 San Anselmo Erica Freeman Building Official
45 San Anselmo Scott Schneider Asst. PW Director
46 San Rafael Quinn Gardner Deputy Emergency Services Coord. 47 San Rafael Cory Bytof Sustainability
48 San Rafael Joanna Kwok Senior Civil Engineer
49 San Rafael Kate Hagemann Climate Adaptation & Resilience Planner 50 Sausalito Andrew Davidson Senior Engineer/ DPW
51 Sausalito Kevin McGowan Director of Public Works
52 Sausalito Brandon Phipps Planning Director
53 Tiburon Sam Bonifacio Assistant Planner
54 Tiburon Dina Tasini Director of Community Development 55 Tiburon Laurie Nilsen Emergency Svs, Coord.
Special Districts & Partner Agencies
56 County of Marin Disability
Access Program Laney Davidson Disability Access Manager/ ADA Coordinator 57 County of Marin Disability
Access Program Peter Mendoza Disability Access Manager/ ADA Coordinator 58 Emergency Medical
Services Chris Le Baudour EMS Authority
59 Fire Departments Jason Weber Fire Chief
60 Golden Gate Bridge,
Highway & Transportation
District
Daniel Rodriguez Security, Emergency Management Specialist 61 Golden Gate Bridge,
Highway & Transportation
District
Dennis Mulligan General Manager & CEO,
62 Marin City Climate
Resilience and Health
Justice
Terrie Green Executive Director
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Table 2: 2023 MJHMP Planning Team Members
No. Agency Point of Contact Title
63 Marin Center for
Independent Living Peter Mendoza Director of Advocacy and Special Projects 64 Marin City Community
Services District Juanita Edwards Interim General Manager 65 Marin County Community
Development Agency Leslie Lacko Community Development Agency 66 Marin County Flood
Control & Water
Conservation District
Garry Lion Advisory Board Member
67 Marin County Office of
Education Michael Grant Director, Marin County Office of Education 68 Marin County Parks Max Korten General Manager and Director 69 PG&E Mark Van Gorder Government Affairs, North Bay
70 PG&E Ron Karlen PG&E Public Safety Specialist
71 Sonoma Marin Area Rail
Transit (SMART) Jennifer McGill Chief of Police
72 Transportation Authority of
Marin (TAM) Anne Richmond Executive Director
73 Willow Creek School Itoco Garcia Superintendent
State Partners
74 Cal OES - ESC Sarah Finnigan Cal OES, Sr. Emergency Services Coordinator
75 Cal OES, Division of
Safety of Dams Danielle Jessup Coordinator/ Dam Safety Planning Division 76 California Department of
Public Health
Svetlana
Smorodinsky
Disaster Epidemiologist/ Environmental &
Occupational Emergency Preparedness
Team
77 California Department of
Public Health
Patrice
Chamberlain
Health Program Specialist II/ Environmental
& Occupational Emergency Preparedness
Team
78 California Department of
Water Resources Julia Ekstrom, PhD Supervisor, Urban UnitWater Use Efficiency Branch 79 Caltrans Trang Hoang Senior Transportation Engr/ Office of Advance Planning
80 Caltrans Markus Lansdowne Caltrans D4 Emergency Coordinator Federal Partners
81 Army Corps of Engineers Jessica Ludy Flood Risk Management, Equity, and Environmental Justice
82 National Park Service Stephen Kasierski OneTam
83 US Coast Guard LT Tony Solares Sector SF Waterways Safety Branch 84 US Coast Guard MST1 Brandon M.
Ward Emergency Management Specialist
85 US Coast Guard LT William K.
Harris USCG SEC San Francisco
Table 250: 2023 MJHMP Planning Team Members
Several opportunities were provided for the groups listed above to participate in the City of Mill Valley’s planning process. At the beginning of the planning process, invitations were extended to these groups to actively participate on the Planning Team. Participants from these groups assisted in the process by attending several videoconferencing meetings where hazard 931
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vulnerability and risk were discussed along with hazard mitigation strategies and actions.
Planning Team members provided data and other applicable information directly as requested in meetings, emails, telephone calls, videoconferencing, worksheets, or through data contained on their websites or as maintained by their offices. This information was used to develop hazard vulnerability and risk profiles along with mitigation actions.
These key agencies, organizations, and advisory groups received meeting announcements, agendas, and minutes by e-mail throughout the plan update process. They supported the effort by attending meetings or providing feedback on issues. All the agencies were provided with an opportunity to comment on this plan update and were provided with a copy of the plan to review and offer edits and revisions. They were also provided access to the Marin County OEM hazard mitigation plan website to review all planning documents and hazard mapping tools.
Each was sent an e-mail message informing them that draft portions of the plan were available for review. In addition, the complete draft plan was sent to the California Governor’s Office of Emergency Services (Cal OES) and FEMA Region IX for a pre-adoption review to ensure program compliance.
In addition, through the public meetings conducted at the beginning of the planning process, members of the planning team, the public, and other key stakeholders were invited to participate in the planning process through public outreach activities.
Further as part of the public outreach process, all planning areas engaged in public outreach and education by providing information on their website or though press releases directing the public to the main Marin County OEM website that provided coordinated and detailed public information of the planning process and how the public could participate. All planning areas were invited to attend the public meetings and to review and comment on the plan prior to submittal to Cal OES and FEMA. Additional public outreach action is detailed in the 1.2.4 PUBLIC ENGAGEMENT section of this annex.
The following planning meetings were held with the planning team:
Table 3: Town of San Anselmo & Marin County OA MJHMP Planning Meetings No. Date Attendees Meeting Planning Meeting Objectives
1 10/26/22 Steering
Committee
Project Overview
Meeting
• Plan Overview – Steps and
Timeline
• Planning Process
• Steering Committee Role
2 11/9/22 Steering
Committee
Steering
Committee
Kickoff Meeting
• Hazard Mitigation and Emergency
Management Overview
• Plan Overview – Steps and
Timeline
• Community Overview
• Planning Process
• Hazard Identification and Risk
Assessment
• Stakeholders and Planning Team
Identification
3 12/6/22 Steering
Committee,
Planning Team
Kickoff Meeting
• Hazard Mitigation and Emergency
Management Overview
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Table 3: Town of San Anselmo & Marin County OA MJHMP Planning Meetings No. Date Attendees Meeting Planning Meeting Objectives
Planning
Team
• Plan Overview – Steps and
Timeline
• Community Overview
• Planning Process
• Hazard Identification and Risk
Assessment
4 02/07/23 Steering
Committee
Steering
Committee
Hazard Profile
Meeting
• Jurisdictional Letter of
Commitment
• Identify Planning Team Members
• Hazard Risk Ranking Worksheets
• Jurisdictional Profiles
• Jurisdictional/ District Capability
Assessment
• 2018 Hazard Mitigation Project
Status Update
5 03/07/23
Steering
Committee/
Planning
Team
Planning Team
Public Outreach
Strategy Meeting
• Planning Goals and Objectives
• Hazard Risk Ranking Worksheets
• Jurisdictional Profiles
• Jurisdictional/ District Capability
Assessment
• 2018 Hazard Mitigation Project
Status Update
• Public Outreach Strategy
6 04/04/23 Steering
Committee
Steering
Committee
Meeting
• HMGP (DR-4683) Funding
Timeline
• Public Outreach
• Planning Goals and Objectives
• Jurisdictional Hazard Vulnerability
Maps
• Jurisdictional Profiles
• Jurisdictional/ District Capability
Assessment
• 2018 Hazard Mitigation Project
Status Update
7 04/13/23
General
Public,
Steering
Committee,
Planning
Team
Public Outreach
Town Hall
Meeting #1
(In-person and
virtual on Zoom)
Thursday, 6:00
pm to 7:30 pm
Marin County
BOS Chambers
• Meeting translated live in Spanish
with 29 language subtitle capability
for virtual participants.
• Meeting also interpreted in
American Sign Language
• Meeting recorded and posted on
Hazard Mitigation website.
• Hazard Mitigation and Emergency
Management Overview
• Planning Process
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Table 3: Town of San Anselmo & Marin County OA MJHMP Planning Meetings No. Date Attendees Meeting Planning Meeting Objectives
• Hazard Identification and Risk
Assessment
• Planning Goals and Objectives
• Hazard Mitigation Projects
• Community Input
8 04/29/23
General
Public,
Steering
Committee,
Planning
Team
Public Outreach
Town Hall
Meeting #2
(In-person and
virtual on Zoom)
Saturday, 10:00
am to 11:30 am
Marin County
Health and
Wellness Center
• Meeting translated live in Spanish
with 29 language subtitle capability
for virtual participants.
• Meeting also interpreted in
American Sign Language
• Meeting recorded and posted on
Hazard Mitigation website.
• Hazard Mitigation and Emergency
Management Overview
• Planning Process
• Hazard Identification and Risk
Assessment
• Planning Goals and Objectives
• Hazard Mitigation Projects
• Community Input
9 05/31/23 Steering
Committee
Steering
Committee
Hazard Ranking
Meeting
• HMGP (DR-4683) Funding
Timeline
• Public Outreach Status
• Jurisdictional Hazard Vulnerability
Maps
• OEM Overview of Hazard Maps
and Marin Maps
• Marin Co. MJHMP Risk
Assessment Tool Overview
• 2018 Hazard Mitigation Project
Status Update
• Hazard Working Groups
10 06/27/23
Steering
Committee,
Planning
Team
Planning Team
Meeting
• HMGP (DR-4683) & BRIC Grant
Funding Timeline
• Public Outreach Status
• Jurisdictional Hazard Risk
Assessment Tool
• OEM Overview of Hazard Maps
and Marin Maps
• Marin County OA Hazards over the
Last 5-Years
• 2018 Hazard Mitigation Project
Status Update
• 2023 Hazard Mitigation
Projects/Capital Improvement
Projects
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Table 3: Town of San Anselmo & Marin County OA MJHMP Planning Meetings No. Date Attendees Meeting Planning Meeting Objectives
• Hazard Working Groups
11 07/01/23-
09/01/23
Steering
Committee
Members
Steering
Committee
Members Plan
Development
Sessions
• Individual phone or conference
calls with planning jurisdictions and
districts to answer specific
questions and assist them in
developing their profile annex.
12 11/27/23
Steering
Committee,
Planning
Team
Planning Team
Meeting
• Presentation and review of the
Draft Marin County OA MJHMP
and Jurisdictional/District Annexes
13 11/28/23
General
Public
Public Outreach
Presentation on
Marin County
Office of
Emergency
Management
Website
• Presentation and review of the
Draft Marin County OA MJHMP
and Jurisdictional/District Annexes.
• Opportunity for public comment
and questions and answers.
Table 251: Town of San Anselmo & Marin County OA MJHMP Planning Meetings
1.2.4 PUBLIC ENGAGEMENT
Early discussions with the Marin County OEM established the initial plan for public engagement to ensure a meaningful and inclusive public process with a focus on equity and accessible to the whole community. The Public Outreach efforts mirrored the Planning Team approach with a unified effort, led by the County OEM, involving all participating jurisdictions and districts. Public outreach for this plan update began at the beginning of the plan development process with a detailed press release informing the community of the purpose of the hazard mitigation planning process for the Marin County OA planning area and to invite the public to participate in the process.
Public involvement activities for this plan update were conducted by the County and all participating jurisdictions and districts and included press releases; website postings; a community survey; stakeholder and public meetings; and the collection of public and stakeholder comments on the draft plan which was posted on the County website. Information provided to the public included an overview of the mitigation status and successes resulting from implementation of the 2018 plan as well as information on the processes, new risk assessment data, and proposed mitigation strategies for the plan update.
Equity and Whole Community Approach
The Marin County OEM and the Steering Committee prioritized equity and engagement of the whole community in the development of the Marin County OA MJHMP by establishing a framework with key actions for each step of the planning process. Elements of the equity approach included:
Engaging hard-to-reach populations
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Town Hall meetings were conducted at different familiar locations within the county where people could easily access them and were conducted on both a weekday and weekend, and in the evening and during the daytime. The meetings were offered in-person with a virtual broadcast using Zoom videoconferencing and streamed live on Marin County OEM Facebook account. After the meeting, Marin County OEM uploaded the recorded meeting to their website to allow the public on demand access to the meeting.
Translation and Interpretation Services
The survey and outreach materials were provided in both English and Spanish to improve accessibility among populations with limited English proficiency. The website uses Google Translate for accessibility in multiple languages. Interpretation services were offered for both town hall meetings. Each town hall meeting included live Spanish translation and subtitles, Live American Sign Language (ASL/CDI) interpretation, the ability for the Zoom videoconferencing attendee to activate subtitles in 29 different languages, and vision accessible PowerPoint slide.
Three stakeholder and public meetings were held, two at the beginning of the plan development process and one prior to finalizing the updated plan. Where appropriate, stakeholder and public comments and recommendations were incorporated into the final plan, including the sections that address mitigation goals and strategies. Specifically, public comments were obtained during the plan development process and prior to plan finalization.
All press releases and website postings are on file with the Marin County OEM. Public meetings were advertised in a variety of ways to maximize outreach efforts to both targeted groups and to the public at large. Advertisement mechanisms for these meetings and for involvement in the overall MJHMP development process include:
• Development and publishing of an MJHMP public outreach article • Providing press releases to local newspapers and radio stations • Posting meeting announcements on the local County MJHMP website • Email to established email lists
• Personal phone calls
The public outreach activities were conducted with participation from and on behalf of all jurisdictions participating in this plan.
The Steering Committee has made the commitment to periodically bring this plan before the public through public meetings and community posting so that citizens may make input as strategies and implementation actions change. Public meetings will continue to be held twice a year after the first and third MJHMP meetings. Public meetings will continue to be stand-alone meetings but may also follow a council meeting or other official government meeting. The public will continue to be invited to public meetings via social media messaging, newspaper invitations, and through the website for each jurisdiction participating in the plan. Each jurisdiction is responsible for assuring that their citizenry is informed when deemed appropriate by the Steering Committee.
WEBSITE
At the beginning of the plan update process, Marin County OEM established a hazard mitigation website https://emergency.marincounty.org/pages/lhmp on behalf of all the planning areas to 936
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ensure consistent messaging and information, to keep the public posted on plan development milestones, and to solicit relevant input. The website also provided information on signing up for Alert Marin, provided detailed information about the hazard mitigation process and plan development, provided a URL and QR code link to the survey in both English and Spanish, and provided information about upcoming town hall meetings. (See Figure 1) The site’s address was publicized in all press releases, surveys and public town hall meetings. Each planning partner also established a link on their own agency website.
Information on the plan development process, the Steering Committee, a link to the Hazard Mitigation survey, and drafts of the plan were made available to the public on the site. The County of Marin intends to keep a website active after the plan’s completion to keep the public informed about successful mitigation projects and future plan updates.
Figure 507: Marin County OEM MJHMP Website
PUBLIC MEETINGS
Two separate Marin County OA MJHMP Public Town Hall Meeting were conducted at different locations within the County, on different days of the week and during different times of the day. This effort was to ensure the greatest equity and access by the public to enable participation in the process. The Marin County OEM outreach strategy is to “meet people where they are.” Each Town Hall Meeting included, live Spanish translation and subtitles, Live American Sign Language (ASL/CDI) interpretation, the ability for the Zoom videoconferencing attendee to activate subtitles in to 28 different languages, and vision accessible PowerPoint slide.
The first Town Hall Meeting was conducted on Thursday, April 13, 2023, from 6:00 pm to 7:30 pm, at the Marin County Board of Supervisors Chambers, Marin County Civic Center, 3501 Civic Center Drive, Room #330 San Rafael, CA 94903. The in-person meeting was also broadcast virtually using Zoom videoconferencing and streamed live on Marin County OEM Facebook account. Each of the jurisdictions participating in the MJHMP released a 937
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Press Release on their respective websites announcing the Public Town Hall Meeting and providing the date, time, and URL link to the Zoom Meeting for the public to log in and attend the Zoom Meeting. Marin County OEM also posted a notice for the Public Town Hall Meeting on their Facebook account. At the conclusion of the presentation, a question and answer session was held to answer questions from the attendees.
The second Town Hall Meeting was conducted on Saturday, April 29, 2023, from 10:00 am to 11:30 am, at the Marin County Health and Wellness Center, 3240 Kerner Ave. Rooms #109 and #110 San Rafael, CA. 94903. The meeting followed the same format as the first and hosted the same access level of equity and accessibility.
The Marin County OA MJHMP Public Town Hall Meeting was recorded and downloaded from Zoom and made available to all of the jurisdictions and districts to place on their websites and local Access TV for the public to view.
Meeting participants were also invited to complete the Hazard Mitigation Survey and were provided the URL link to the Survey Monkey website to complete the survey.
Figure 508: Marin County OA MJHMP Public Town Hall Meeting
SOCIAL MEDIA
The Marin County OA utilized several forms of social media to reach residents and customers. Information about the Hazard Mitigation Planning process was communicated to the public via Facebook, Twitter, and local access TV. Residents and customers were invited to complete the Hazard Mitigation Plan survey which was accessible via an attached URL or QR Code and provide feedback on potential hazard mitigation projects or programs.
The results of the survey were provided to each of the planning partners and used to support the jurisdictional annex process. Each planning partner was able to use the survey results to help identify actions as follows:
• Gauge the public’s perception of risk and identify what citizens are concerned about. • Identify the best ways to communicate with the public. 938
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• Determine the level of public support for different mitigation strategies. • Understand the public’s willingness to invest in hazard mitigation.
PRESS RELEASES
Press releases were distributed over the course of the plan’s development as key milestones were achieved and prior to each Marin County OA MJHMP Public Town Hall Meeting. All press releases were made available to the community in both English and Spanish.
Figure 509: Hazard Mitigation Plan Public Outreach Press Release SURVEY
A hazard mitigation plan survey (see Figure 4) was developed by the Steering Committee and made available to the public in both English and Spanish. The survey was used to gauge household preparedness for natural hazards and the level of knowledge of tools and techniques that assist in reducing risk and loss from natural hazards. This survey was designed to help identify areas vulnerable to one or more natural hazards. The answers to its ten questions helped guide the Steering Committee in defining our hazards, and selecting goals, objectives, and mitigation strategies. The survey was available on the hazard mitigation plan website, advertised in press releases, and at town hall meetings. Finally, the survey and the process of public input were advertised throughout the course of the planning process. The survey was available to the public on March 13, 2023, and closed on June 12, 2023. At the conclusion of the planning process 293 surveys were completed by the public.
Public Comments Considered by the Planning Team
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The Planning Team used the following information gathered from the Public Outreach Survey to inform decisions regarding hazard mitigation strategies, actions, and priorities. • Climate Change, Wildfire, and Drought were the top hazards of concern for the public. • Text messages, mail, and the County website were the preferred methods for receiving hazard mitigation information.
• 48% of respondents expressed that they were “Very Much” concerned and 31% were “Moderately” concerned that a natural disaster could impact their home or place of residence.
• 85% of respondents own their own home.
• 99% of respondents have access to the internet.
Figure 510: Hazard Mitigation Plan Survey
Public Outreach Survey
h�ps://www.surveymonkey.com/r/MarincountyMJHMP
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PUBLIC COMMENT ON THE PLAN
To solicit public feedback on the draft plan, Marin OEM engaged in a multi-faceted approach intended to reach as many Marin residents as possible, including members of the community who are under-served and under-represented. All members of the community had the opportunity to provide initial comments on the plan during a two-week period from Wednesday, December 4, 2023, to Wednesday, December 18, 2023. Although the initial comment period was listed as two weeks, the public could submit comments indefinitely via the County’s website to support the County’s continuous improvement efforts. The base plan, as well as city, town and special district annexes, were available for download on emergency.marincounty.org (include photos). The website additionally asked for feedback in a survey in English and Spanish (include photos), the survey was designed to establish where that person lives or works, their top hazards of concern, elicit feedback on the plan and offer a place for them to share projects to reduce risk in their community. The survey collected responses from the community in English and in Spanish.
The website and survey were shared through traditional and social media (photos) The Marin Independent Journal (Marin IJ) used the press release to write an article (hopefully; include photos). Social media accounts were updated four times with an initial ask, two reminders, and a closing announcement. The Marin OEM Public Information Officer coordinated with the Marin County Public Information Officers (MAPIO) working group to distribute information to partner jurisdictions (city, town, and special districts) to share this information on their social media sites and with the communities in the area.
To reach those who may not be engaged digitally, the planning team worked with Marin County Community Response Teams, (CRTs are a collaboration of non-profit organizations supporting underrepresented communities in four zones) to conduct outreach with half-sheet flyers in English and Spanish to share in the 4 CRT zones (southern Marin, north Marin, west Marin, San Rafael). These half sheets were also shared county-wide at libraries, including in areas not covered by CRTs, like at the Fairfax library. CRTs are designed to reach Marin’s traditionally underserved and underrepresented communities, so by conducting outreach through this method, we were able to inform residents who may not have been engaged otherwise, including residents in Marin City, West Marin, and the Canal District of San Rafael.
After December 18, 2023, the various participating jurisdiction and district profiles remained on the Marin County OEM website for public comments. The Town of San Anselmo had an additional 14-day comment period for the Town of San Anselmo Community Profile where their profile was posted on the Town website for final public comment from January 29 – February 5, 2024.
The 14-day public comment period gave the public an opportunity to comment on the draft plan update prior to the plan’s submittal to Cal OES. Comments received on the draft plan are available upon request. All comments were reviewed by the planning team and incorporated into the draft plan as appropriate.
Public Comments Considered by the Planning Team
The Marin County OEM posted the draft Hazard Mitigation Plan and hazard mitigation actions on their website and solicited public comments on the content. The Town of San 941
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Anselmo distributed press releases directing the community to the Marin County OEM website to review the draft plans. The Planning Team gathered public comments and information on the Marin County OEM website regarding proposed and current Hazard Mitigation Actions. The Planning Team used the comments and suggestions to inform decisions regarding hazard mitigation strategies, actions, and priorities. Most comments included ideas for hazard mitigation projects and comments on the effectiveness of current mitigation projects. These comments were used to revise the proposed hazard mitigation actions which resulted in the final list of hazard mitigation actions listed in 3.5 Hazard Mitigation Actions.
1.3 OVERVIEW AND HISTORY
For thousands of years prior to 1800, the Coast Miwok Indians lived and were sustained by the land that is now called Ross Valley. The Coast Miwok revered the land, plants and animals of the Ross Valley through tribal cultural beliefs and practices. European diseases eventually decimated the Indian population. The settlement in 1817 of Mission San Rafael, with its vast land holding, also resulted in further incursions into areas occupied by the Coast Miwok Indians.
After the Mexican Revolution of 1821, the “land grant” system of parceling out land gave rise to what we now know as the County of Marin. San Anselmo was originally part of an 8,877-acre Mexican land grant to Juan B.R. Cooper in 1840 known as Ranch Punta de Quentin Canada de San Anselmo. The Town of San Anselmo itself was named in honor of James San Anselmo, who purchased the land in 1857 for $50,000. San Anselmo built his home on Redwood Drive and moved there with his wife and three children. When James San Anselmo died in 1862 his wife, Annie San Anselmo, was forced to sell a portion of James San Anselmo’ larger land holdings to pay each of their daughters $10,000. The 297 acres she had remaining make up part of the Town of San Anselmo today.
The Town of San Anselmo was incorporated as a town in 1907. The Town of San Anselmo had an estimated population of 12,830 in 2020, with 5,518 housing units in the Town. The Town has a total area of 2.677 square miles. The median income for a household in the Town is $153,381 and the per capita income for the Town is $87,951. Approximately 0 percent of families and 3.9 percent of the population is below the poverty line (2020 data, U.S. Census Bureau). 942
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Figure 511: Map of the Town of San Anselmo in Marin County Source: Marin County OEM
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Figure 512: Map of the Town of San Anselmo
Source: Marin County OEM
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1.4 GOVERNMENT
The Town of San Anselmo was incorporated as a town in 1907 and is governed by a five-person Town Council. Each year the Town Council elects one of its members to serve as Mayor, the executive head of the Town; and appoints a Town Manager, the administrative head of the Town.
The Town consists of 9 departments: the Administration and Finance, Building, Fire Department, Human Resources, Library, Planning, Police, Public Works, and Recreation.
The Town Council assumes responsibility for the adoption of this plan; and the Town Manager will oversee its implementation.
The Ross Valley Fire Department provides Fire services to the City of San Anselmo. In 2012, the Town of San Anselmo voted to consolidate with Ross Valley Fire Department, joining Ross, Fairfax, and Sleepy Hollow to provide fire protection to Town of San Anselmo. In 2012, Ross Valley Fire Department's Board of Directors voted to consolidate fire services with the Town of Ross, incorporating the Town of Ross Fire Station 18, and the 9 firefighters employed there, into the Ross Valley Fire Department.
The Central Marin Police Authority is a full-service Police agency for the communities of Corte Madera, Larkspur, San Anselmo and portions of Greenbrae comprising of approximately 35,000 residents. The communities consolidated police services on January 1, 2013, into the Central Marin Police Authority formed under a Joint Powers Agreement (JPA).
1.5 WEATHER AND CLIMATE
The Town of San Anselmo lies 46 feet above sea level. In San Anselmo, the summers are long, comfortable, arid, and mostly clear and the winters are short, cold, wet, and partly cloudy. Over the course of the year, the temperature typically varies from 43°F to 71°F and is rarely below 36°F or above 84°F. The difference in precipitation between the driest month and the wettest month is 5 inches. The annual rainfall is 18 inches. The month with the highest relative humidity is February (80%). The month with the lowest relative humidity is June (70%). The month which sees the most rainfall is January. The driest month of the year is July. 945
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January February March April May June July August September October November December Avg.
Temperature
°C (°F)
9.3 °C
(48.7) °F
9.8 °C
(49.7) °F
10.9 °C
(51.6)
°F
11.8 °C
(53.2)
°F
13.6 °C
(56.5)
°F
15.6 °C
(60.2)
°F
16 °C
(60.8)
°F
16.4 °C
(61.4)
°F
16.4 °C
(61.5) °F
15 °C
(58.9) °F
11.9 °C
(53.5) °F
9.5 °C
(49) °F
Min.
Temperature
°C (°F)
6.3 °C
(43.4) °F
6.9 °C
(44.4) °F
7.8 °C
(46.1)
°F
8.5 °C
(47.4)
°F
10.1 °C
(50.2)
°F
11.7 °C
(53)
°F
12.3 °C
(54.2)
°F
12.9 °C
(55.2)
°F
12.6 °C
(54.7) °F
11.5 °C
(52.7) °F
8.9 °C
(48) °F
6.8 °C
(44.2) °F
Max.
Temperature
°C (°F)
13.3 °C
(56) °F
13.9 °C
(57) °F
15.1 °C
(59.2)
°F
16.2 °C
(61.2)
°F
18.3 °C
(64.9)
°F
20.9 °C
(69.6)
°F
21.2 °C
(70.2)
°F
21.5 °C
(70.8)
°F
21.9 °C
(71.4) °F
20 °C
(68.1) °F
16.2 °C
(61.2) °F
13.1 °C
(55.7) °F
Precipitation /
Rainfall mm
(in)
118
(4)
124
(4)
88 (3)
41 (1)
22 (0)
5 (0)
1 (0)
2 (0)
2 (0)
25 (0)
58 (2)
114
(4)
Humidity(%) 78% 80% 78% 72% 71% 70% 75% 76% 73% 72% 75% 77% Rainy days (d) 8 7 6 4 3 1 0 0 0 2 5 7
avg. Sun
hours (hours)
5.7 6.4 7.8 9.4 10.0 10.6 9.3 8.5 8.7 7.8 6.7 5.6
Figure 513: The Town of San Anselmo Precipitation and Monthly Temperatures Source: En.Climate-Data.org
1.6 DEMOGRAPHICS
The California Department of Finance shows an overall estimated decrease in the population of the Marin County OA and the Town of San Anselmo since the last plan update in 2018. Of the total estimated 257,135 residents of the Marin County OA in 2022 based on the 2020 U.S.
Census Survey, 190,148 residents live in the incorporated county and 66,987 residents live in the unincorporated county.
The Town of San Anselmo had an estimated population of 12,853 in the 2018 plan. 2020 U.S.
Census Survey estimated the Town’s population at 12,830. However, revised estimates for 2022 estimate the population to decrease to 12,645 population.
Table 4: Town of San Anselmo Estimated Jurisdictional Population Jurisdiction Population 2022
(Estimate)
Population 2020 Population 2018
(Estimate)
Percent Change
2018-2022
Marin County OA 257,135 262,321 262,179 -1.92%
Town of San
Anselmo
12,645 12,830 12,853 -1.62%
Table 252: Town of San Anselmo Estimated Jurisdictional Population Source: California Department of Finance
According to the U.S. Census, the population of The Town of San Anselmo is 12,830 as of 2020. Between 2018-2022, the City’s growth rate increased at an average annual rate of -
1.62%, lower than the historic twenty-year average growth rate of 3.2%. Table 5 shows the population growth comparison of the State of California, The Marin County OA, and the Town of San Anselmo between 2010 - 2020.
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Table 5: Population Change of The Town of San Anselmo
Jurisdiction Total Population Change, 2010-2020
April 1, 2010 April 1, 2020 Number Percent
California 37,253,956 39,538,223 2,284,267 6.1%
Marin County OA 252,409 262,321 9,912 3.9%
San Anselmo, town 12,853 12,830 23 -1.62%
Table 253: Population Change of The Town of San Anselmo Source: Town of San Anselmo Housing Element, US Census Bureau, California Department of Finance Table 6 lists the various languages spoken in the Town of San Anselmo.
Table 6: Languages Spoken in San Anselmo
Primary Language Spoken % of Population
English only 94.2%
Spanish 1.0%
Other Indo-European languages 2.5%
Asian and Pacific Islander languages 2.0%
Other languages 0.3%
Table 254: Languages Spoken in San Anselmo
Source: US Census Bureau (2020)
Figure 514: Races in San Anselmo
Source: City-Data.com
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Table 7: Marin County OA Jurisdictional Housing Stock
2022 and 2018
Year Total Units Single Family Multi-Family Mobile
Detached Attached 2 to 4 5 plus Homes
California
2022
Number 14,583,998 8,341,577 1,010,851 1,168,669 3,500,674 562,223 Percent 100.0% 57.2% 6.9% 8.0% 24.0% 3.9%
2018
Number 14,157,502 8,160,864 985,926 1,129,761 3,318,946 562,005 Percent 100.0% 57.6% 7.0% 8.0% 23.4% 4.0%
Marin County OA
2022
Number 111,879 68,004 11,314 8,524 22,013 1,984
Percent 100.0% 60.8% 10.1% 7.6% 19.7% 1.8%
2018
Number 112,294 68,697 11,318 8,307 21,986 1,986
Percent 100.0% 61.2% 10.1% 7.4% 19.6% 1.8%
Town of San Anselmo
2022
Number 5,539 4,177 266 376 683 37
Percent 100.00% 75.41% 6.37% 141.35% 181.65% 5.42%
2018
Number 5,563 4,211 269 356 690 37
Percent 100.00% 75.70% 6.39% 132.34% 193.82% 5.36%
Table 255: Marin County OA Jurisdictional Housing Stock Source: California Department of Finance
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Figure 515: Town of San Anselmo Zoning Map
Source: Town of San Anselmo Housing Element
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1.7 SOCIAL VULNERABILITY AND RISK
The California Governor’s Office of Emergency Services (Cal OES) has initiated the “Prepare California” grant program focused on building community resilience amongst vulnerable individuals living in the areas of the state most susceptible to natural disasters. The Prepare California Initiative is aimed at reducing long-term risks from natural disasters by investing in local capacity building and mitigation projects designed to protect communities.
Prepare California leverages funds approved in Governor Gavin Newsom’s 2021-22 State Budget and is designed to unlock federal matching funds for community mitigation projects that vulnerable communities would otherwise be unable to access. This program is intended for communities that are the most socially vulnerable and at the highest risk for future natural hazard events. The state identified communities by prioritizing California census tracts according to their estimated hazard exposures and social vulnerability.
The National Risk Index is a dataset and online tool to help illustrate the United States communities most at risk for 18 natural hazards: Avalanche, Coastal Flooding, Cold Wave, Drought, Earthquake, Hail, Heat Wave, Hurricane, Ice Storm, Landslide, Lightning, Riverine Flooding, Strong Wind, Tornado, Tsunami, Volcanic Activity, Wildfire, and Winter Weather.
For purposes of this plan the following National Risk Index (NRI) hazards are profiled in support of eight of the twelve Marin County OA MJHMP Hazards. NRI data was not available for Dam Failure, Land Subsidence, Levee Failure, or Sea Level Rise.
Table 8: NRI Hazards and Marin County OA MJHMP Hazards
NRI Hazards Marin County OA MJHMP Hazards
Earthquake Earthquake
Riverine Flooding Flooding
Coastal Flooding Flooding
Wildfire Wildfire
Landslide Debris Flow
Drought Drought
Heat Wave Severe Weather -Extreme Heat
Tsunami Tsunami
Strong Wind Severe Weather – Wind, Tornado
Table 256: NRI Hazards and Marin County OA MJHMP Hazards Source: FEMA National Risk Index 2023
The National Risk Index leverages available source data for Expected Annual Loss due to these 18 hazard types, Social Vulnerability, and Community Resilience to develop a baseline relative risk measurement for each United States county and census tract. These measurements are calculated using average past conditions, but they cannot be used to predict future outcomes for a community. The National Risk Index is intended to fill gaps in available data and analyses to better inform federal, state, local, tribal, and territorial decision makers as they develop risk reduction strategies.
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Calculating the Risk Index
Risk Index scores are calculated using an equation that combines scores for Expected Annual Loss due to natural hazards, Social Vulnerability and Community Resilience:
Risk Index = Expected Annual Loss × Social Vulnerability ÷ Community Resilience Hazard Type Risk Index
Hazard type Risk Index scores are calculated using data for only a single hazard type, and reflect a community's Expected Annual Loss value, community risk factors, and the adjustment factor used to calculate the risk value.
Social groups in Census tract 06041111700 have a Very Low susceptibility to the adverse impacts of natural hazards when compared to the rest of the U.S.
Figure 10 illustrates the Social Vulnerability Map for San Anselmo Census Tract 1117.00. Social groups in Census tract 06041117000 have a Relatively Low susceptibility to the adverse impacts of natural hazards when compared to the rest of the U.S.
Table 9 illustrates the NRI Hazard Type Risk Index for San Anselmo Census Tract 1117.00.
Table 9: NRI Hazard Type Risk Index for San Anselmo Census Tract 1117.00 Hazard Type EAL Value Social
Vulnerability
Community
Resilience CRF Risk Value Score
Earthquake $1,968,575 Relatively Low Very High 0.96 $1,883,575 95.8 Riverine Flooding $852,461 Relatively Low Very High 0.96 $815,653 98 Landslide $36,673 Relatively Low Very High 0.96 $35,089 99 Wildfire $21,409 Relatively Low Very High 0.96 $20,484 87.2 Heat Wave $7,364 Relatively Low Very High 0.96 $7,046 45.4 Tornado $4,457 Relatively Low Very High 0.96 $4,265 10
Strong Wind $259 Relatively Low Very High 0.96 $248 8.7 Drought $0 Relatively Low Very High 0.96 $0 0
Table 257: NRI Hazard Type Risk Index for San Anselmo Census Tract 1117.00 Source: FEMA National Risk Index 2023
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Figure 516: Town of San Anselmo Social Vulnerability Map Census Tract 1181.00 Source: FEMA National Risk Index 2023
Most socially vulnerable residents in the Marin County OA reside in parts of Novato, parts of San Rafael, including in and around the Canal District, the Greenbrae neighborhood of Larkspur, and the unincorporated areas of Marin City and Santa Venetia. This aligns with what the County knows about Marin residents. However, discrepancy lies in the western, more rural area of the county. West Marin is comprised of seven villages, and other populated areas, that are distanced from the centralized resources in the eastern part of the county. Across three local elementary schools in West Marin (2022-2023 school year), students eligible for free and reduced lunch program represent between 41 percent and 62 percent of the student population, a reflection of the financial capacity of local families. West Marin is home to many farms that may employ and house underrecognized workers who may not have taken part in a census survey, which informs the Social Vulnerability Index. In the last three months of 2022, bus routes traveling to West Marin (Rural Routes) were the only service category to have increased in ridership since the-COVID pandemic (increase 0.1%; Marin Transit, 2022), which indicates that West Marin residents may be more reliant on public transportation than other Marin residents.
However, this data continues to adjust based upon the increase in alternate methods of mass transportation. Therefore, the County of Marin acknowledges that unique social factors in West Marin require different approaches than other parts of the County.
The Town of San Anselmo has a “Relatively Low” Social Vulnerability rating. The median income for a household in the Town is $153,381 and the per capita income for the Town is $87,951.
Approximately 0 percent of families and 3.9 percent of the total population is below the poverty line (2021 data, U.S. Census Bureau).
While the Town of San Anselmo has a “Relatively Low” Social Vulnerability rating and the median household income is high, approximately 17 percent of San Anselmo’s population, 2,145 people, are 65 years in age or older. Approximately 26 percent of the Town’s households 952
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have a senior head-of-household, and the vast majority (74 percent) of these householders own their homes. Approximately 43 percent of San Anselmo’s senior households qualify as lower income households (less than 80 percent of the Area Median Income), and 299 seniors have incomes which fall below the level of poverty (less than 30 percent of Area Median Income).
Needs for seniors with disabilities include smaller and more efficient housing, barrier free and accessible housing, and housing with health care and/or personal care for daily living. Such specific housing needs can drive up the cost of suitable housing, resulting in a higher housing cost burden for seniors.
Seniors often express concern for their ability to pay for necessities. The 2012-2016 Marin County Aging Area Plan found that 17 percent of senior homeowners in the Marin County OA had trouble paying for home repairs over the past year. Affording home repairs is the most reported housing issue for seniors who had been in their homes for more than 30 years. While most seniors prefer to stay in their homes, some may find that property maintenance costs make it difficult to age in place. In San Anselmo, approximately 545 lower-income senior households own their own home and 234 lower-income senior households rent. In 2017, approximately 28 percent of senior households were housing cost burdened.
Disabilities and limited mobility can create additional special housing needs for seniors.
Approximately 17 percent of senior residents in San Anselmo have some type of disability, which may limit their access to housing. An estimated 94 seniors have independent living difficulty, 55 have a self-care difficulty, and 165 have ambulatory difficulty. Housing with enhanced accessibility features can support independent living for seniors as they continue to age.
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1.8 ECONOMY AND TAX BASE
The Town of San Anselmo is one of the Marin County OA’s primary retail, service, and commercial center. Table 10 shows income by household in The Town of San Anselmo as of 2019.
Table 258: Household Income for The Town of San Anselmo as of 2021 Source: US Census Bureau American Community Survey 2021 Estimates Table 11 shows the percentage of people in The Town of San Anselmo over the age of 16 employed by industry.
Table 11: Town of San Anselmo Civilian Employed Population 16 years+ by Industry Industry Estimated Employed Percent
Civilian employed population 16 years and over 6,922 -
Agriculture, forestry, fishing and hunting, and mining 29 0.42% Construction 309 4.46%
Manufacturing 342 4.94%
Wholesale trade 180 2.60%
Retail trade 575 8.31%
Transportation and warehousing, and utilities 222 3.21% Information 287 4.15%
Finance and insurance, and real estate and rental and
leasing
666 9.62%
Professional, scientific, and management, and
administrative and waste management services
1623 23.45%
Educational services, and health care and social
assistance
1604 23.17%
Table 10: Household Income for the Town of San Anselmo as of 2019 Household Income Number Percent
Total Households 4,995 -
Less than $10,000 125 2.5
$10,000 to $14,999 75 1.5
$15,000 to $24,999 185 3.7
$25,000 to $34,999 120 2.4
$35,000 to $49,999 235 4.7
$50,000 to $74,999 350 7.0
$75,000 to $99,999 509 10.2
$100,000 to $149,999 774 15.5
$150,000 to $199,999 789 15.8
$200,000 or more 1,838 36.8
Median household income (dollars) $153,381
Mean household income (dollars) $217,811
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Arts, entertainment, and recreation, and accommodation
and food services
568 8.21%
Other services, except public administration 290 4.19%
Public administration 227 3.28%
Table 259: Town of San Anselmo Civilian Employed Population 16 years+ by Industry Source: US Census Bureau American Community Survey 2021 Estimates
1.9 CRITICAL FACILITIES
The following list of facilities has been determined to be critical to the ability of the Town of San Anselmo to fulfill the requirements of its mission during an emergency:
Table 12: Town of San Anselmo Critical Facilities
Category Name Address Fire Severity
Zone
Flood
Zone
54. Fire
Fire: Ross Valley Fire
Department (RVY) / Station
19 777 San Anselmo Avenue
San Anselmo, CA 94960 N AE
55. Fire
Fire: Ross Valley Fire
Department (RVY) / Station
20 150 Butterfield Road
San Anselmo, CA 94960 High AE
56. Law Central Marin Police 525 San Anselmo Avenue
San Anselmo, CA 94960 N AE
57. Local
Government San Anselmo Town Hall 525 San Anselmo AvenueSan Anselmo, CA 94960 N AE
58. Community
Center
Isabel Cook Community
Center (ICC)
1000 Sir Francis Drake Blvd.
San Anselmo, CA 94960 N X
59. Library San Anselmo Public Library 110 Tunstead Ave. San Anselmo, CA 94960 N AE
60. School Brookside Elementary School 116 Butterfield Road San Anselmo, CA 94960 High AE/X
61. School Wade Thomas Elementary
School
150 Ross Avenue
San Anselmo, CA 94960 N X
62. School St. Anselm School 40 Belle Avenue
San Anselmo, CA 94960 N AE
63. School Archie Williams High School 1327 Sir Francis Drake San Anselmo, CA 94960 N AE/X
64. School Parkside Preschool and
Daycare
1000 Sir Francis Drake Blvd.
San Anselmo, CA 94960 N X
65. School University of Redlands 105 Seminary Road
San Anselmo, CA 94960 N AE/X
Table 260: Town of San Anselmo Critical Facilities
Source: Town of San Anselmo
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Figure 517: Town of San Anselmo Critical Facilities and Infrastructure Source: Marin County OEM
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1.10 HISTORICAL PROPERTIES
The Town of San Anselmo has no registered historically significant homes, public buildings, or landmarks. To inventory these resources, the HMPC collected information from a number of sources:
• California Department of Parks and Recreation Office of Historic Preservation (OHP) OHP is responsible for the administration of federally and state mandated historic preservation programs to further the identification, evaluation, registration, and protection of California’s irreplaceable archaeological and historical resources. OHP administers the National Register of Historic Places, the California Register of Historical Resources, California Historical Landmarks, and the California Points of Historical Interest programs.
• Town of San Anselmo Chamber of Commerce.
• Town of San Anselmo website.
As defined by the National Environmental Policy Act (NEPA), any property over 50 years of age is considered a potential historic resource and is potentially eligible for the National or California Register. Thus, in the event that the property is to be altered, or has been altered, as the result of a major federal action, the property must be evaluated under the guidelines set forth by NEPA. Structural mitigation projects are considered alterations for the purpose of this regulation. Similar regulations exist for buildings under the California Environmental Quality Act (CEQA).
Table 13: Historic Sites in San Anselmo
Name/Landmark
State Plaque
Number
National
Register
(NR)
State
Landmark
California
Register
Date
Listed
(NR)
Jurisdiction
None
Table 261: Historic Sites in The Town of San Anselmo
Source: California Office of Historic Preservation and the National Register of Historic Places 957
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SECTION 2.0: HAZARD IDENTIFICATION AND RISK
ASSESSMENT
The Town of San Anselmo identified hazards that affect the city and developed natural hazard profiles based upon the countywide risk assessment, past events and their impacts. Figure 12 shows the top hazards that the Jurisdiction is at risk from according to the hazard mitigation Steering Committee.
Figure 518: Town of San Anselmo Risk Assessment – Planning Team Top Hazards Figure 13: Risk Rank Categorization
Risk Level Risk Numerical Score
High Risk 12 - 16
Serious Risk 8 - 11
Moderate Risk 4 - 7
Low Risk 1 - 3
Figure 519: Hazard Risk Categorization
Each Marin County OA MJHMP participating jurisdiction and organization reviewed and approved the Top Hazards identified by the Planning Team. Each participating jurisdiction and district then completed a more complex assessment tool to further develop their hazard assessment and prioritization.
The planning process used the available FEMA tools to evaluate all the possible threats faced.
The primary tool selected was the Hazard Assessment and Prioritization Tool. This matrix allowed the participating jurisdiction or organization to assess their own level of vulnerability and 17 17 17 17
16 11
10 6
5 0 0 0
0 2
4 6
8 10
12 14
16 18
Weighted Rank Percentage Value
Hazard Types
Hazards by Rank
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mitigation capability. Each participating Jurisdiction and organization assessed the top hazards for:
• Probability/ Likelihood of Future Events
• Geographic Extent
• Magnitude/ Severity
• Climate Change Influence
• Significance
Probability/ Likelihood of Future Events
• Unlikely: Occurs in intervals greater than 100 years - Less than 1% probability of occurrence in the next year or a recurrence interval greater than 100 years. • Occasional: Occurring every 11 to 100 years - 1-10% probability of occurrence in the next year or a recurrence interval of 11 to 100 years.
• Likely: Occurring every 1 to 10 years - 10-90% probability of occurrence in the next year or recurrence interval of 1 to 10 years.
• Highly Likely: Occurring almost every year - 90-100% probability of occurrence in the next year or a recurrence interval of less than 1 year.
Geographic Extent
• Negligible: Less than 10% of the planning area
• Limited: 10-25% of the planning area
• Significant: 25-75% of planning area
• Extensive: 75-100% of planning area
Magnitude/ Severity
• Weak: Limited classification on scientific scale, slow speed of onset or short duration of event, resulting in little to no damage.
• Moderate: Moderate classification on scientific scale, moderate speed of onset or moderate duration of event, resulting in some damage and loss of services for days. • Severe: Severe classification on scientific scale, fast speed of onset or long duration of event, resulting in devastating damage and loss of services for weeks or months. • Extreme: Extreme classification on scientific scale, immediate onset or extended duration of event, resulting in catastrophic damage and uninhabitable conditions.
Table 14: Select Hazards Magnitude and Severity Scale
Hazard Scale/Index Weak Moderate Severe Extreme
Drought Palmer Drought
Severity Index +1.99 to -1.99 -2.00 to -2.99 -3.00 to -3.99 -4.00 and below Earthquake Modified
Mercalli I to IV V to VII VIII IX to XII
Richter
Magnitude 2,3 4,5 6 7,8
Tornado Fujita Tornado
Damage Scale FO F1, F2 F3 F4, F5
Table 262: Select Hazards Magnitude/ Severity Scale or Index 959
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Climate Change Influence
• Low: Minimal potential impact
• Medium: Moderate potential impact
• High: Widespread potential impact
Significance
• Low: Minimal potential impact - Two or more criteria fall in lower classifications, or the event has a minimal impact on the planning area. This rating is sometimes used for hazards with a minimal or unknown record of occurrences or for hazards with minimal mitigation potential.
• Medium: Moderate potential impact - The criteria fall mostly in the middle ranges of classifications and the event’s impacts on the planning area are noticeable but not devastating. This rating is sometimes used for hazards with a high extent rating but very low probability rating.
• High: Widespread potential impact - The criteria consistently fall in the high classifications and the event is likely/highly likely to occur with.
2.1 CLIMATE CHANGE
The County of Marin and associated jurisdictions profiled jointly recognize that the earth’s climate is forcibly being augmented due to humans’ reliance on fossil fuels and non-natural resources which pose negative impacts on the earth’s climate. Reliance on fossil fuels and nonnatural products results in the climate shifting to include unseasonable temperatures, more frequent and intense storms, prolonged heat and cold events, and a greater reliance on technological advancements to maintain the wellbeing of community members and balance of the environment. The forced adaptation to climatic shifts is necessary for the County and jurisdictions to understand and include with these assessments.
Locally to Marin, drought and rain events have already had devastating impacts to critical infrastructure, agriculture, and water resources; and globally, unseasonable temperatures have been identified as the cause for enhanced wildfires, severe droughts, ice sheets and glaciers disappearing, and persons emigrating from their countries due to a lack of sustainable, local resources. Melting land ice contributes additional water to the oceans and as ocean temperatures rise the water expands, both of which contribute to increase rates of sea level rise.
Marin is bordered on the west by the Pacific Ocean and on the east by San Francisco Bay, making it particularly vulnerable to flooding and erosion caused by sea level rise.
The cause of current climate change is largely human activity, burning fossil fuels, natural gas, oil, and coal. Burning these materials releases greenhouse gases into Earth’s atmosphere.
Greenhouse gases trap heat from the sun’s rays inside the atmosphere causing Earth’s average temperature to rise. This rise in the planet's temperature was formerly called, “global warming”, but climate change has shown to include both intense heat and cold shifts. The warming of the planet impacts local and regional climates. Throughout Earth's history, climate has continually changed; however, when occurring naturally, this is a slower process that has taken place over hundreds and thousands of years. The human influenced climate change that is happening now is occurring at an abnormally faster rate with devastating results. 960
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GLOBAL OBSERVED AND PROJECTED IMPACTS AND RISKS
Source: Intergovernmental Panel on Climate Change, Headline Statements from the Summary for Policymakers, 2022
• Human-induced climate change, including more frequent and intense extreme events, has caused widespread adverse impacts and related losses and damages to nature and people, beyond natural climate variability.
• Global warming, reaching 1.5°C in the near-term, would cause unavoidable increases in multiple climate hazards and present multiple risks to ecosystems and humans. • Beyond 2040 and depending on the level of global warming, climate change will lead to numerous risks to natural and human systems.
• The magnitude and rate of climate change and associated risks depend strongly on near-term mitigation and adaptation actions, and projected adverse impacts and related losses and damages escalate with every increment of global warming. • Multiple climate hazards will occur simultaneously, and multiple climatic and non-climatic risks will interact, resulting in compounding overall risk and risks cascading across sectors and regions.
FUTURE TRENDS/ IMPACTS
Source: Study Confirms Climate Models are Getting Future Warming Projections Right – Climate Change: Vital Signs of the Planet (nasa.gov)
Global Warming
• If global warming transiently exceeds 1.5°C in the coming decades or later, then many human and natural systems will face additional severe risks. • An estimated 60% of today’s methane emissions are the result of human activities. The largest sources of methane are agriculture, fossil fuels, and decomposition of landfill waste.
• The concentration of methane in the atmosphere has more than doubled over the past 200 years. Scientists estimate that this increase is responsible for 20 to 30% of climate warming since the Industrial Revolution (which began in 1750). • According to the most recent National Climate Assessment, droughts in the Southwest and heat waves (periods of abnormally hot weather lasting days to weeks) are projected to become more intense, and cold waves less intense and less frequent. • The last eight years have been the hottest years on record for the globe. 961
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Figure 520: NASA Global Temperature Change CO2 Gas
Source: NASA Global Climate Change, 2022
Figure 521: NASA Global Temperature Change 1884 to 2022 Source: NASA Global Climate Change, 2022
Drought
• A NASA-led study in 2022 concluded that the 22-year-long megadrought in southwestern US was the driest the territory had experienced in at least 1,200 years and was expected to persist through at least 2022.
Sea Level Rise
• Global sea levels are rising as a result of human-caused global warming, with recent rates being unprecedented over the past 2,500-plus years. • U.S. Sea Level Likely to Rise 1 to 6.6 Feet by 2100.
• Global sea level has risen about 8 inches (0.2 meters) since reliable record-keeping began in 1880. By 2100, scientists project that it will rise at least another foot (0.3 meters), but possibly as high as 6.6 feet (2 meters) in a high-emissions scenario. 962
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• Sea ice cover in the Arctic Ocean is expected to continue decreasing, and the Arctic Ocean will very likely become essentially ice-free in late summer if current projections hold. This change is expected to occur before mid-century. • An indicator of changes in the Arctic sea ice minimum over time. Arctic sea ice extent both affects and is affected by global climate change.
Figure 522: NASA Global Temperature Change Sea Level
Source: NASA Global Climate Change, 2022
Wildfire
• Warming temperatures have extended and intensified wildfire season in the West, where long-term drought in the region has heightened the risk of fires. • Scientists estimate that human-caused climate change has already doubled the area of forest burned in recent decades. By around 2050, the amount of land consumed by wildfires in Western states is projected to further increase by two to six times. • Even in traditionally rainy regions like the Southeast, wildfires are projected to increase by about 30%.
•
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Flooding (Precipitation)
• Climate change is having an uneven effect on precipitation (rain and snow) in the United States, with some locations experiencing increased precipitation and flooding, while others suffer from drought.
• On average, more winter and spring precipitation is projected for the northern United States, and less for the Southwest, over this century.
• Projections of future climate over the U.S. suggest that the recent trend toward increased heavy precipitation events will continue. This means that while it may rain less frequently in some regions (such as the Southwest), when it does rain, increased intensity of rain fall may occur and may become more common.
Extreme Cold
• The length of the frost-free season, and the corresponding growing season, has been increasing since the 1980s, with the largest increases occurring in the western United States.
According to the California Natural Resource Agency (CNRA), climate change is already affecting California and is projected to continue to do so well into the foreseeable future.
Current and projected changes include increased temperatures, sea level rise, a reduced winter snowpack, altered precipitation patterns, and more frequent storm events. Over the long term, reducing greenhouse gases can help make these changes less severe, but the changes cannot be avoided entirely. Unavoidable climate impacts result in a variety of secondary consequences including detrimental impacts on human health and safety, economic continuity, ecosystem integrity and provision of basic services. Climate change is being profiled in the 2023 Marin County OA MJHMP as a standalone hazard while addressing each of the other natural hazards.
The Marin County OA is considering climate change issues when identifying future mitigation actions.
California is experiencing a climate crisis that is increasingly taking a toll on the health and wellbeing of its people and on its unique and diverse ecosystems. Every Californian has suffered from the effects of record high temperatures, dry winters, prolonged drought, and proliferating wildfires in recent years. California’s biodiversity is threatened as alterations to habitat conditions brought about by a changing climate are occurring at a pace that could overwhelm the ability of plant and animal species to adapt.
Indicators of Climate Change in California
Source: 2022 Report: Indicators of Climate Change in California | OEHHA • Since 1895, annual average air temperatures in California have increased by about 2.5 degrees Fahrenheit (°F). Warming occurred at a faster rate beginning in the 1980s. • Recent years have been especially warm: Eight of the ten warmest years on record occurred between 2012 and 2022; 2014 was the warmest year on record. • Of all the Western states, California endured the hottest temperatures for the longest time, driving the average statewide temperature to the second warmest over the past 128 years.
• Extreme heat ranks among the deadliest of all climate-driven hazards in California, with physical, social, political, and economic factors effecting the capacity of individuals, 964
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workers, and communities to adapt, and with the most severe impacts often on communities who experience the greatest social and health inequities. • Glaciers have essentially disappeared from the Trinity Alps in Northern California • In 2020, wildfire smoke plumes were present in each county for at least 46 days. • The 2022 fire season saw more fires than the previous fire season along with continued extreme drought and heat conditions.
• The drought, begun in 2019, was the third statewide drought declared in California since 2000.
• This drought has been marked by extreme swings; the state received record-breaking amounts of precipitation in October and December 2021 that were offset by the driest January, February, and March 2022 dating back more than 100 years. The year 2023 opened with California simultaneously managing both drought and flood emergencies. • A series of storms in late December 2022 and early January 2023 broke rural levees, disrupted power, flooded roads, downed trees, and eroded coastal land. • Sea level rise accelerates coastal erosion, worsens coastal flooding during large storms and peak tidal events, and impacts important infrastructure positioned along our state’s 1,100-mile coast.
• The western drought which impacted all of California and the western United States was nearly lifted due to unseasonably heavy rains in late 2022 and early 2023.
The graph below shows the relative change, in millimeters, in sea levels at Crescent City (1933- 2020), San Francisco (1900-2020), and La Jolla (1925-2020).
Figure 523: Annual Mean Sea Level Trends
Source: 2022 Report: Indicators of Climate Change in California | OEHHA 965
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Climate Change in the Marin County Operational Area
Climate change is already having significant impacts across California. Temperatures are warming, heat waves are more frequent, and precipitation has become increasingly variable.
Climate change will continue to alter Marin County OA ecosystems as a result of rising temperatures, changes in precipitation, and sea level rise, which will increase the severity and occurrence of natural hazards across the Marin County OA well into the future. Coastal cooling processes that keep temperatures down, such as fog, will continue to decrease. Rising temperatures will exacerbate drought conditions and raise the potential for significant wildfires and associated smoke as vegetation becomes drier and tree mortality increases. Forested woodlands that play a major role in carbon reduction will gradually transition into chaparral and shrublands. There will be more extreme storms and weather events, including expanded heat waves and increased rain events with changes in precipitation. Significant rain events will lead to an increase in flooding and the potential for severe landslides. Shoreline communities will become inundated with sea level rise, storm surge, and high tide events. Marshlands and wetlands that act as natural storm barriers will disappear as they transition into open water.
Notable impacts from climate change that are already evident in the Marin County OA and surrounding region as identified in a 2020 Marin County Civil Grand Jury Report include:
• From 1895-2018, the average temperature in Marin County increased by 2.3 degrees Fahrenheit.
• Over the past century, sea level rise in the San Francisco Bay Area rose by eight inches and has accelerated rapidly since 2011.
• The threat of wildfires in 2019 was so severe that Pacific Gas and Electric shut off electric power to the County for multiple days.
Climate change will continue to affect homes, businesses, infrastructure, utilities, transportation systems and agriculture across the Marin County OA. The risk to socially vulnerable populations will increase as they feel the immediate impacts of climate change more significantly and are less able to adapt to climate change and recover from its impacts.
The Marin County OA has adopted numerous planning initiatives and mitigation measures to help combat the effects of climate change across the OA. The Marin Climate Energy Partnership (MCEP), which is a partnership program of Marin County jurisdictions, the County, and Marin County regional agencies, adapted a model Climate Action Plan (CAP) that is intended to support countywide implementation efforts and is currently being used to update additional climate action plans for other jurisdictions in Marin County. The CAP supports the Climate Action Plan for the unincorporated County, which was completed in 2020. The MCEP also collects data and report on progress in meeting each County jurisdictions’ individual greenhouse gas emission targets. In June 2023, the County published the Greenhouse Gas Inventory for Unincorporated Community Emissions for the Year 2021. Marin County OA jurisdictions have already met their greenhouse reduction goals for 2020 and are about halfway to meeting the statewide goal to reduce emissions 40% below 1990 levels by the year 2030.
Marin County also formed a Sea Level Marin Adaptation Response Team in 2018 and had a Sea Level Rise Vulnerability Assessment and associated Adaptation Report completed for the County and each of its jurisdictions in 2017 as part of their Bay Waterfront Adaptation and Vulnerability Evaluation. Additional Marin County OA climate change mitigation initiatives 966
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include Marin Clean Energy, Electrify Marin, the Marin Solar Project, the Marin Energy Watch Partnership, Resilient Neighborhoods, and Drawdown Marin.
2.2 HAZARDS
Of the hazards profiled in the Marin County OA MJHMP, those noted in the table are specific for the Town of San Anselmo as per the planning team.
Table 15: Town of San Anselmo Hazard Risk Assessment
Hazard
Probability/
Likelihood of
Future Events
Geographic
Extent
Magnitude/
Severity
Climate
Change
Influence
Significance Risk
Score
Dam Failure Unlikely Negligible Weak Low Low 5.00
Debris Flow Likely Limited Moderate Medium Medium 11.00 Drought Likely Extensive Extreme High High 17.00
Earthquake Occasional Extensive Extreme High High 16.00 Flooding Occasional Limited Moderate Medium Medium 10.00 Land Subsidence Unlikely Negligible Moderate Low Low 6.00 Severe Weather –
Extreme Heat Likely Extensive Extreme High High 17.00
Severe Weather –
High Wind/Tornado Likely Extensive Extreme High High 17.00 Wildfire Likely Extensive Extreme High High 17.00
Table 263: Town of San Anselmo Hazard Risk Assessment
Source: Town of San Anselmo
Omitted Hazards
The Town of San Anselmo does not have risk exposure to Levee Failure, Sea Level Rise, or Tsunamis.
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Table 16: Marin County OA Hazard Risk Assessment
Hazard
Probability/
Likelihood of
Future Events
Geographic
Extent
Magnitude/
Severity
Climate
Change
Influence
Significance Risk
Score
Dam Failure Unlikely Negligible Extreme Low Medium 9.00 Debris Flow,
Erosion, Landslide,
Post-Fire Debris
Flow
Occasional Extensive Severe Medium Medium 13.00
Drought Highly Likely Extensive Moderate High High 16.00 Earthquake Highly Likely Extensive Extreme None High 15.00 Flooding Highly Likely Limited Severe High Medium 14.00 Land Subsidence
(Sinkhole) Occasional Limited Moderate Medium Medium 10.00 Levee Failure Unlikely Negligible Moderate Medium High 9.00 Sea Level Rise Highly Likely Limited Extreme High High 16.00 Severe Weather –
Extreme Heat Highly Likely Extensive Moderate High Medium 15.00 Severe Weather –
High Wind/Tornado Highly Likely Extensive Moderate High Medium 15.00 Tsunami Highly Likely Limited Extreme Medium High 15.00 Wildfire Highly Likely Significant Severe High High 16.00 Table 264: Marin County OA Hazard Risk Assessment
Source: County of Marin
2.2.1 DAM FAILURE
Dams are manmade structures built for a variety of uses including flood protection, power generation, agriculture, water supply, and recreation. When dams are constructed for flood protection, they are usually engineered to withstand a flood with a computed risk of occurrence.
For example, a dam may be designed to contain a flood at a location on a stream that has a certain probability of occurring in any one year. If prolonged periods of rainfall and flooding occur that exceed the design requirements, that structure may be overtopped and fail.
Overtopping is the primary cause of earthen dam failure in the United States.
Dam failure is the uncontrolled release of impounded water from behind a dam. Flooding, earthquakes, blockages, landslides, lack of maintenance, improper operation, poor construction, vandalism, and terrorism can all cause a dam to fail. Dam failure causes downstream flooding that can affect life and property. Dam failures can result from any one or a combination of the following causes:
• Earthquake
• Inadequate spillway capacity resulting in excess overtopping flows 968
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• Internal erosion caused by embankment or foundation leakage, or piping or rodent activity
• Improper design
• Improper maintenance
• Negligent operation
• Failure of upstream dams on the same waterway
Water released by a failed dam generates tremendous energy and can cause a flood that is catastrophic to life and property. A catastrophic dam failure could challenge local response capabilities and require evacuations to save lives. Impacts to life safety will depend on the warning time and the resources available to notify and evacuate the public. Major loss of life could result as well as potentially catastrophic effects to roads, bridges, and homes. Electric generating facilities and transmission lines could also be damaged and affect life support systems in communities outside the immediate hazard area. Associated water supply, water quality and health concerns could also be an issue. Factors that influence the potential severity of a full or partial dam failure are the amount of water impounded; the density, type, and value of development and infrastructure located downstream; and the speed of failure.
In general, there are three types of dams: concrete arch or hydraulic fill, earth and rockfill, and concrete gravity. Each type of dam has different failure characteristics. A concrete arch or hydraulic fill dam can fail almost instantaneously, where the flood wave builds up rapidly to a peak then gradually declines. An earth-rockfill dam fails gradually due to erosion of the breach, where a flood wave will build gradually to a peak and then decline until the reservoir is empty. A concrete gravity dam can fail instantaneously or gradually with a corresponding buildup and decline of the flood wave.
The California Department of Water Resources (DWR) Division of Safety of Dams (DSOD) has jurisdiction over impoundments that meet certain capacity and height criteria. Embankments that are less than six feet high and impoundments that can store less than 15 acre-feet are nonjurisdictional. Additionally, dams that are less than 25 feet high can impound up to 50 acre-feet without being jurisdictional. The Cal DWR DSOD assigns hazard ratings to large dams within the State. The following two factors are considered when assigning hazard ratings: existing land use and land use controls (zoning) downstream of the dam. Dams are classified in three categories that identify the potential hazard to life and property:
• High hazard indicates that a failure would most probably result in the loss of life • Significant hazard indicates that a failure could result in appreciable property damage
• Low hazard indicates that failure would result in only minimal property damage and loss of life is unlikely
Since 1929, the state has supervised all non-federal dams in California to prevent failure for the purpose of safeguarding life and protecting property. Supervision is carried out through the state’s Dam Safety Program under the jurisdiction of DWR. The legislation requiring state supervision was passed in response to the St. Francis Dam failure and concerns about the potential risks to the general populace from a number of water storage dams. The law requires:
• Examination and approval or repair of dams completed prior to August 14, 1929, the effective date of the statute.
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• Approval of plans and specifications for and supervision of construction of new dams and the enlargement, alteration, repair, or removal of existing dams. • Supervision of maintenance and operation of all dams under the state’s jurisdiction.
The 1963 failure of the Baldwin Hills Dam in Southern California led the Legislature to amend the California Water Code to include within state jurisdiction both new and existing off-stream storage facilities.
Dams and reservoirs subject to state supervision are defined in California Water Code §6002 through §6004, with exemptions defined in §6004 and §6025. In administering the Dam Safety Program, DWR must comply with the provisions of the California Environmental Quality Act (CEQA). As such, all formal dam approval and revocation actions must be preceded by appropriate environmental documentation.
In 1972, Congress moved to reduce the hazards from the 28,000 non-federal dams in the country by passing Public Law 92-367, the National Dam Inspection Act. With the passage of this law, Congress authorized the U.S. Army Corps of Engineers (USACE) to inventory dams located in the United States. The action was spurred by two disastrous earthen dam failures during the year, in West Virginia and South Dakota, that caused a total of 300 deaths.
The Water Resources Development Act of 1986 (P.L 99-662) authorized USACE to maintain and periodically publish an updated National Inventory of Dams (NID). The Water Resources Development Act of 1996 (P.L. 104-303), Section 215, re-authorized periodic updates of the NID by USACE.
While there are no dams located within San Anselmo, the Town could be impacted by a failure of the Phoenix Lake Dam in the unincorporated County of Marin. The dam has storage of 612- acre feet of water that could be released down Ross Creek in the event of a full sunny-day dam failure. Water could extend out 500 feet on both sides of Ross Creek for about five miles at a depth up to thirty feet in some areas before it dumps into Corte Madera Creek and San Anselmo Creek. Flooding could continue north along San Anselmo Creek into San Anselmo, extending along Sir Francis Drake Boulevard to the intersection of Red Hill Avenue. Flooding could extend out 1,000 feet along the west side of the creek in the southern part of the Town and 200 feet along both sides of the creek further north, flooding dozens of homes, most of the main commercial area, and part of the San Anselmo School, the San Anselmo Town Hall and the San Anselmo Emergency Operations Center in two to ten feet of water approximately 10-20 minutes after the dam fails.
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Figure 524: Town of San Anselmo Dam Inundation Critical Facilities and Infrastructure Source: Marin County OEM
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Figure 525: Phoenix Lake Dam Inundation Area – San Anselmo Source: California Department of Water Resources
There is no record of a failure of any regulated dam located in the Marin County OA. On December 29, 2022, Phoenix Lake hit capacity after recent rains and the dam saw some spillover with no impacts.
Climate Change and Future Development Considerations
Most dams in the United States are aging and are at significant risk from increased storm events as a result of climate change. The average dam age in the United States is 60 years, and more than 8,000 dams in the United States including the Phoenix Lake Dam are over 90 years old. More than 200 U.S. dams have failed in bad weather since 2000. As the climate warms, rain events are predicted to become more intense. An increase in rainfall and runoff as a result of climate change will increase the potential for higher water levels in reservoirs across the Marin County OA, placing increased stress on its dams and increasing the potential for a dam failure. As development increases in the populated areas of the Marin County OA downstream of its dams, particularly in the inundation area of the Phoenix Lake Dam, the potential for significant impacts to residents and infrastructure will only increase. This area includes part of San Anselmo. Future development along San Anselmo Creek in and near downtown could expose additional people and structures to risk of a dam failure.
2.2.2 DEBRIS FLOWS
For the purposes of the Marin County OA MJHMP, debris flows are classified as landslides (including rockslides) and mud flows.
A landside is the breaking away and gravity-driven downward movement of hill slope materials, which can travel at speeds ranging from fractions of an inch per year to tens of miles per hour 972
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depending on the slope steepness and water content of the rock/soil mass. Landslides range from the size of an automobile to a mile or more in length and width and, due to their sheer weight and speed, can cause serious damage and loss of life. The rate of a landslide is affected by the type and extent of vegetation, slope angle, degree of water saturation, strength of the rocks, and the mass and thickness of the deposit. Some of the natural causes of this instability are earthquakes, weak materials, stream and coastal erosion, and heavy rainfall. In addition, certain human activities tend to make the earth materials less stable and increase the chance of ground failure. These activities include extensive irrigation, poor drainage or groundwater withdrawal, removal of stabilizing vegetation and over-steepening of slopes by undercutting them or overloading them with artificial fill. These activities can cause slope failure, which normally produce landslides.
Landslide material types are often broadly categorized as either rock or soil, or a combination of the two for complex movements. Rock refers to hard or firm bedrock that was intact and in place prior to slope movement. Soil, either residual or transported material, means unconsolidated particles. The distinction between rock and soil is most often based on interpretation of geomorphic characteristics within landslide deposits but can also be inferred from geologic characteristics of the parent material described on maps or in the field. Landslide movements are also based on the geomorphic expression of the landslide deposit and source area, and are categorized as falls, topples, spreads, slides, or flows. Falls are masses of soil or rock that dislodge from steep slopes and free fall. Topples move by the forward pivoting of a mass around an axis below the displaced mass. Lateral spreads move by horizontal extension and shear or tensile fractures. Slides displace masses of material along one or more discrete planes and can either be rotational or transitional. Flows mobilize as a deforming, viscous mass without a discrete failure plane.
Natural conditions that contribute to landslide include the following:
• Degree of slope
• Water (heavy rain, river flows, or wave action)
• Unconsolidated soil or soft rock and sediments
• Lack of vegetation (no stabilizing root structure)
• Previous wildfires and other forest disturbances
• Earthquake
In addition, many human activities tend to make the earth materials less stable and, thus, increase the chance of ground movement. Human activities contribute to soil instability through grading of steep slopes or overloading them with artificial fill, by extensive irrigation, construction of impermeable surfaces, excessive groundwater withdrawal, and removal of stabilizing vegetation.
Another hazard related to landslide and erosion is the fall of a detached mass of rock from a cliff or down a very steep slope (rockfall). Weathering and decomposition of geological materials produce conditions favorable to rockfalls. Other causes include ice wedging, root growth, or ground shaking (earthquake). Destructive landslides and rockfalls usually occur very suddenly with little or no warning time and are short in duration.
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common cause of death in a landslide is trauma or suffocation by entrapment. Broken power, water, gas or sewage pipes can also result in injury or illness in the population affected, such as water-borne diseases, electrocution or lacerations from falling debris. People affected by landslides can also have short- and long-term mental health effects due to loss of family, property, livestock or crops. Landslides can also greatly impact the health system and essential services, such as water, electricity or communication lines.
Landslide susceptibly can be characterized by looking at both slope class and rock strength.
Landslide susceptibility classes express the generalization that on very low slopes, landslide susceptibility is low even in weak rock, and that landslide susceptibility increases with slope and in weaker rocks. Very high landslide susceptibility includes very steep slopes in hard rocks and moderate to very steep slopes in weak rocks. Figure 20 shows landslide susceptibility classes.
Figure 526: Landslide Susceptibility Classes
Source: USGS
A mud flow is a general term for a mass-movement landform and process characterized by a flowing mass of fine-grained earth material with a high degree of fluidity. Heavy rainfall, snowmelt, or high levels of groundwater flowing through cracked bedrock may trigger a movement of soil or sediments. Floods and debris flows may also occur when strong rains on hill or mountain slopes cause extensive erosion and/or what is known as "channel scour".
Some broad mud flows are rather viscous and therefore slow; others begin very quickly and continue like an avalanche. Mud flows are composed of at least 50% silt and clay-sized materials and up to 30% water.
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The point where a muddy material begins to flow depends on its grain size and the water content. Fine grainy material or soil has a smaller friction angle than a coarse sediment or a debris flow, but falling rock pieces can trigger a material flow, too. When a mud flow occurs it is given four named areas, the 'main scarp', in bigger mud flows the 'upper and lower shelves', and the 'toe'. See Figure 21 for the typical areas of a mud flow, with shelves (right) and without (left). The main scarp will be the original area of incidence, the toe is the last affected area(s).
The upper and lower shelves are located wherever there is a large dip (due to mountain or natural drop) in the mud flow's path. A mud flow can have many shelves.
Figure 527: Mud Flow Areas
Source: Washington Department of Natural Resources
If large enough, mud flows can devastate villages and country-sides. Mud flows are common in mountain areas prone to wildfire, where they have destroyed many homes built on hillsides without sufficient support after fires destroy vegetation holding the land. The area most generally recognized as being at risk of a dangerous mud flow are:
• Areas where wildfires or human modification of the land have destroyed vegetation • Areas where landslides have occurred before
• Steep slopes and areas at the bottom of slopes or canyons • Slopes that have been altered for construction of buildings and roads • Channels along streams and rivers
• Areas where surface runoff is directed
A landslide in San Anselmo would most likely occur on the northern and southern sides of the Town where the terrain is steeper and is more susceptible to movement of hill slope materials.
This area of San Anselmo is primarily residential and consists of numerous winding streets and hillside homes that could be damaged or destroyed by a landslide. The Ross Valley Fire Staton #20, Brookside Elementary School, the Irene M. Hunt School and the San Anselmo Montessori School lie in a landslide susceptibility area. Most of the main commercial area of San Anselmo lies outside a landslide susceptibility area though several businesses along both Sir Francis Drake Boulevard and Red Hill Avenue near Red Hill have some susceptibility to a landslide. 975
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Figure 528: Town of San Anselmo Debris Flow Critical Facilities and Infrastructure Source: Marin County OEM
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A landslide having major impacts on any of the roads in this area could affect the ability of residents to reach their homes. An earthquake has the potential to cause landslides throughout this area. A wildfire and subsequent rain event in any of the open space to the east and west of San Anselmo, including Bald Hill Open Space Preserve, Hawthorne Canyon Open Space Preserve, Faude Open Space Park, Sorich Park and Red Hill could potentially contribute to debris flows in San Anselmo. San Anselmo Creek flows from the Mount Tamalpais watershed into San Anselmo and could potentially contribute to a debris flow that could impact bridges, residences and other structures in the Town, affecting ingress and egress to residential areas.
San Anselmo declared a state of emergency in 1958 from damage caused by heavy rains when homes were in danger of sliding into the creek on Forest Avenue.
On 1/3–1/5/1982, a severe storm caused numerous landslides across the Town, isolating several areas and blocking access roads. Six houses were destroyed by mudslides and phone and electricity was out.
On March 27, 2011, approximately five inches of rain fell within a 50-minute period in San Anselmo and there were five landslides.
On 2/12-2/14/2019, a series of storms caused two landslides. One of the landslides occurred between Summit Road and Francis Avenue, damaging a retaining wall which resulted in $250,000 in damages. A slide on Francis Drake Boulevard at a cactus nursery carried part of the nursery fence along with some power lines down toward San Anselmo Creek.
Climate Change and Future Development Considerations
Extreme storm events and more frequent wildfires as a result of climate change have the potential to increase the amount and severity of landslides, including disastrous debris flows.
Climate change is leading to more volatile precipitation patterns around the world with very dry stretches punctuated by storms that drop large amounts of rain in a short amount of time.
Landslides in wetter regions of California, including the Marin County OA, move on average faster and farther downhill during rainy periods compared to drought years, according to a 2022 study by the American Geophysical Union (AGU)33, showing the increased potential for landslides in the Marin County OA in rainy years. As development increases in the numerous canyons and around the many open spaces of the Marin County OA, the potential for significant impacts from a landslide and/or mudflow increases. Further development of the residential areas of San Anselmo that have a higher landslide susceptibility will expose more people and property to landslide risk. With increased wildfire potential as a result of climate change, more residents around San Anselmo could be susceptible to post-fire debris flows. This includes areas around San Anselmo Creek and Sleepy Hollow Creek. Future development should take into account the movement of mud and debris in waterways after a major rain event. Adequate space adjacent to susceptible waterways should be maintained free of development to allow for the passage of mud and debris, and catchment basins should be built in these areas to help capture any excess mud and debris.
33 Landslide Sensitivity and Response to Precipitation Changes in Wet and Dry Climates. https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2022GL099499 977
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2.2.3 DROUGHT
A drought is a deficiency in precipitation over an extended period, usually a season or more, resulting in a water shortage causing adverse impacts on vegetation, animals, and/or people. It is a normal recurrent feature of climate that occurs in virtually all climate zones, from very wet to very dry. Drought is a temporary aberration from normal climatic conditions and can thus vary significantly from one region to another. Droughts occur slowly, over a multi-year period, and it is often not obvious or easy to quantify when a drought begins and ends. Drought is a complex issue involving many factors—it occurs when a normal amount of moisture is not available to satisfy an area’s usual water-consuming activities.
There are several types of drought which can often be defined regionally based on its effects:
• Meteorological drought is usually defined by a period of below average water supply, based on the degree of dryness (in comparison to normal or average) and the duration of the dry period. Drought onset generally occurs with a meteorological drought.
• Agricultural drought occurs when there is an inadequate water supply to meet the needs of the state’s crops and other agricultural operations such as livestock.
Agricultural drought links various characteristics of meteorological (or hydrological) drought to agricultural impacts, focusing on precipitation shortages, soil water deficits, reduced ground water or reservoir levels needed for irrigation. • Hydrological drought is defined as deficiencies in surface and subsurface water supplies. It is generally measured as stream flow, snowpack, and as lake, reservoir, and groundwater levels. Hydrological drought usually occurs following periods of extended precipitation shortfalls.
• Socioeconomic drought occurs when a drought impacts health, well-being, and quality of life, or when a drought starts to have an adverse economic impact on a region.
Drought can occur in all areas of San Anselmo, though it’s effects would be most felt in the mountainous areas to the north and south where the risk of wildfire would increase. Dry trees in public spaces like the Bald Hill Open Space Preserve, Hawthorne Canyon Open Space Preserve, Faude Open Space Park, Sorich Park and Red Hill can become a safety hazard to the public due to falling limbs or the toppling of the tree itself.
The Town of San Anselmo has experienced four droughts since rainfall records began: 1920s, 1970s, 1980s and 2012-2017. Historically, the Marin Municipal Water District (MMWD) which serves San Anselmo has been able to meet demands during periods of extreme drought with a combination of rationing, conservation, and increased purchases of imported water supply from the Sonoma County Water Agency (SCWA). There is a probability of future drought events. In the future as the climate changes, less frequent, more intense storms are expected; these storms have an increased potential to cause flooding. Additionally, with less frequent and more intense storms, there will likely also be extended dry periods.
Since there is no agriculture in San Anselmo and zoning precludes agricultural uses, prolonged periods of drought do not cause crop losses in the town. Lack of water affects the Town creeks, groundwater supply, threatened species (Steelhead), and the Town’s ability to suppress 978
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wildfires. A drought may result in dry vegetation in San Anselmo that is susceptible to ignition and wildfires.
Drought is anticipated to cause loss of landscaping. The Town does not have means to measure the cost of this loss to the community or its economic base. The San Anselmo Town Hall, Memorial Park, and a popular private park in the downtown area have natural grass lawns and fields that could be impacted by severe water rationing that includes public facilities.
Renovating the Memorial Park turf and irrigation is currently estimated at approximately $700,000. Town median landscaping may also be damaged by severe water.
Climate Change and Future Development Considerations
Climate change increases the odds of worsening drought. Warmer temperatures enhance evaporation, which reduces surface water and dries out soils and vegetation. This makes periods with low precipitation in the summer drier than they would be in cooler conditions.
Climate also alters the timing of water availability as warmer winter temperatures cause less precipitation to fall. During droughts, communities in the Marin County OA including San Anselmo may have limited access to water for household use, including drinking, cooking, cleaning, and watering plants, as well as for agriculture, transportation, and power generation.
Drought may lead to higher water costs, rationing, or even the decimation of important water sources like wells in the Marin County OA. As more people move into the Marin County OA and the San Anselmo, additional strain will be placed on the OA’s water supply. Drought can affect livestock and crops in the Marin County OA, impacting its economy. Drought can increase the occurrence and severity of wildfires and tree mortality in the Marin County OA including in the open spaces in and around San Anselmo. Impacts to residents and infrastructure from wildfire as a result of drought will increase as more development occurs in the mountainous areas of the Marin County OA including San Anselmo where wildfires are more likely to occur. Future development in this area and in the mountainous areas of San Anselmo could expose people to drier summer conditions that could increase their vulnerability to wildfire. Drought also increases the amount of carbon dioxide in the atmosphere, including by decreasing land productivity, which reduces the amount of vegetation storing carbon dioxide. In addition, increases in drought-related wildfire and soil erosion can release carbon dioxide sequestered in trees and plants back into the atmosphere. This will only worsen climate change for the Marin County OA into the future. When considering future development, the Marin County OA including San Anselmo can help prepare for both future droughts and climate change by practicing and promoting water conservation and enhancing water efficiency throughout landscapes, city plans, and water infrastructure. The Marin County OA can also identify alternative water supplies, create drought emergency plans, and encourage farmers to plant drought-resistant crops.
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2.2.4 EARTHQUAKE
Earthquakes are sudden rolling or shaking events caused by movement under the earth’s surface. Earthquakes happen along cracks in the earth's surface, called fault lines, and can be felt over large areas, although they usually last less than one minute.
The amount of energy released during an earthquake is usually expressed as a magnitude and is currently measured by seismologists on the Moment Magnitude (Mw Scale). The Mw Scale was developed to succeed the previously used Richter Scale and is measured on a scale of zero to ten with increasing values reflecting increasing intensity.
The other commonly used measure of earthquake severity is intensity, which is an expression of the amount of shaking at any given location on the ground service. Intensity is most commonly measured on the Modified Mercalli Intensity (MMI) Scale (see Figure 23).
Figure 529: Modified Mercalli Intensity Scale
Source: USGS
Figure 24 gives intensities (measured on the MMI scale) that are typically observed at locations near the epicenter or earthquakes of different magnitudes. 980
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Figure 530: Mercalli Scale vs. Magnitude
Source: USGS
The extent of ground shaking also depends in large part on how soft the underlying soil is. Soft soils amplify ground shaking (see Figure 25). This was observed during the 1989 Loma Prieta Earthquake when the most significant damages experienced in San Francisco were in the Marina District, which was built on fill.
Figure 531: Soil Types
Source: USGS
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An earthquake fault is defined as “a fracture or fracture zone in the earth’s crust along which there has been displacement of the sides relative to one another.” For the purpose of planning there are two types of faults, active and inactive. Active faults have experienced displacement in historic time, suggesting that future displacement may be expected. Inactive faults show no evidence of movement in recent geologic time, suggesting that these faults are dormant.
Two types of fault movement represent possible hazards to structures in the immediate vicinity of the fault: fault creep and sudden fault displacement. Fault creep, a slow movement of one side of a fault relative to the other, can cause cracking and buckling of sidewalks and foundations even without perceptible ground shaking. Sudden fault displacement occurs during an earthquake event and may result in the collapse of buildings or other structures that are found along the fault zone when fault displacement exceeds an inch or two. The only protection against damage caused directly by fault displacement is to prohibit construction in the fault zone.
An earthquake could occur anywhere in and around San Anselmo due to the number of active faults within and near the Marin County OA.
Earthquake Shake Intensity
The colors on Figures 26 and 27 represent the level of ground shaking intensity of a potential future earthquake. The result is expressed as the level of ground shaking (expressed as a percentage of gravity) that on average occurs every 500 years.
This map shows the expected relative intensity of ground shaking and damage in California from anticipated future earthquakes. The shaking potential is calculated as the level of ground motion that has a 2% chance of being exceeded in 50 years, which is the same as the level of ground-shaking with about a 2500 year average repeat time. The relatively long-period (1.0 second) earthquake shaking is shown here. Long period-shaking affects tall, relatively flexible buildings, but also correlates well with overall earthquake damage.
Earthquake Shaking Potential Maps for California depict expected intermediate period (1s or 1hz) ground motions with 2% exceedance probability in 50 years. 982
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Figure 532: County of Marin Earthquake Impact and Fault Lines Source: Marin County OEM
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Figure 533: Town of San Anselmo Earthquake Critical Facilities and Infrastructure Source: Marin County OEM
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San Anselmo is near several active faults that have the potential to cause earthquakes that would be a hazard for the Town. The San Andreas Fault runs north and south in the western side of the Marin County OA, approximately 8 miles southwest from San Anselmo. The San Andreas Fault is considered capable of generating a magnitude 8.0 earthquake. The northern section of the Hayward fault is less than 10 miles northeast of San Anselmo. The entire Hayward fault may generate magnitude 7.2 and 7.4 earthquakes. The Rodgers Creek fault is less than fifteen miles northeast of San Anselmo and may generate a magnitude 7.0 earthquake. The San Gregorio fault is less than 10 miles south of San Anselmo and may generate a magnitude 7.3 earthquake. Areas in Town, primarily the low-lying areas adjacent to the San Anselmo Creek and along the Town’s main thoroughfares, have a “moderate” liquefaction susceptibility and could be more susceptible to an earthquake. All of the Town’s critical facilities including its schools, nursing facilities, fire stations, Emergency Operations Center, Town Hall lie in an area of moderate vulnerability to shaking from an earthquake.
Hundreds of homes and dozens of businesses, including the main commercial area of town, lie in this area. Hundreds more homes lie in an area of lower earthquake shaking susceptibility.
Additional vulnerable structures in town include bridges and older buildings that have not undergone major seismic retrofitting. Utility infrastructure throughout the Town could be impacted by an earthquake. Many multifamily apartment buildings were constructed in San Anselmo in the 1950’s and 1960’s that may be considered “soft story” structures. San Anselmo has not yet completed a soft story inventory or implemented a retrofit program. Typical damage to pre-1940 single-family homes include the wood frame coming off its foundation, racking of the cripple walls, the foundation itself cracking, or the chimney breaking at the roof line. A typical problem with houses built during this era is the connection between the wood frame and the foundation. These houses often lack steel bolts or any other type of "tie-down" between the foundation and the wood frame. Since these houses were built before the widespread use of plywood, they also typically lack appropriate shear reinforcing of the cripple walls (the walls between the top of the foundation and the floor diaphragm). Finally, steel reinforcing is often not found in the foundation of these houses or their chimneys. Some of these older houses may have brick foundations with weakly cemented joints. Typical building damage to post-1940 houses does not present widespread problems with foundation anchorage and foundation reinforcing. However, there often is a lack of proper reinforcement of the masonry chimneys. A significant number of post-1940 dwellings may suffer some type of chimney damage. The second major source of damage is damage (or even collapse) of garages with living area above in two-story or split-level homes due to long spans over the garages.
The San Anselmo Building Department completed an inventory of masonry buildings and stone buildings in 2006. All 18 masonry and 3 stone buildings have been reinforced. According to a former building department employee, the San Anselmo Town Hall was constructed in 1911 and renovated in 1976 and 2006. It is a wood building in good condition. Fire station #19 was constructed in 1976 and renovated in 2009-2011; it is also in good condition and not in need of retrofits or upgrades. Fire station #20 was constructed in 1961 and is in satisfactory condition.
The Town Corporation yard buildings are metal framed, constructed in 2002, and in good condition.
A major earthquake event could result in deaths, injuries, property and environmental damage, and disruption of normal government and community services. Hospitals outside of the Town may be impacted by an earthquake. Telephone systems could be affected by system failure, overloads and loss of electrical power. Natural gas leaks pose a fire threat and breaks in the system could affect service to the Town. Water sources could be compromised due to damage to treatment plants, pump stations and/or the pipelines that distribute potable water. 985
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Liquefaction-related damage to water supply pipelines could impair fire suppression, leaving the Town vulnerable to a large fire. Sewage collection systems throughout the Marin County OA may sustain widespread damage if ground movement damages mains or pipelines. Electricity may be interrupted. Landslides may occur. Bridges and roads may be closed because of damage. An earthquake may also result in dam failure. Liquefaction of creeks during the winter storm season could exacerbate flood hazards. The Town may experience road closures from liquefaction, earthquake-triggered landslides, shaking damage to bridges as well as indirect causes of closures such as building damage, hazmat releases, and utility pipeline breaks and fallen trees. The Town of San Anselmo will be affected by the regional impacts of regional transportation disruption, particularly closure of the Golden Gate Bridge. Earthquakes could also cause landslides in the areas around San Anselmo with steeper terrain, causing damage to homes and roads as a result of shifting soils.
San Anselmo hasn’t yet experienced a significant earthquake. The Marin County OA was sparsely populated at the time of the 1906 San Francisco Earthquake, and the effects across San Anselmo the County were relatively minimal. Likewise, the 1989 Loma Prieta Earthquake caused minimal impacts as the epicenter of the quake was further south in Santa Cruz County.
Smaller earthquakes with minimal to no impacts are routinely felt in San Anselmo.
Climate Change and Future Development Considerations
There is no direct link between climate change and seismic activity that could impact the Marin County OA including San Anselmo, so climate change is not expected to cause any changes to the frequency or intensity of seismic shaking. According to a 2018 study by the Institute of Physics (IOP)34, climate change could result in “isostatic rebounds,” or a sudden upward movement of the crust because of reduced downward weight caused by glaciers. As glaciers are known to melt when overall global temperatures increase, climate change could indirectly lead to an increase in seismicity in the Marin County OA including San Anselmo. Climate change could also impact earthquakes felt in the Marin County OA as droughts can further deteriorate existing fault lines and pumping groundwater can put further pressure on the earth’s crust. Future development in the populated areas of Marin County OA where seismic shaking and subsidence are more prevalent could exacerbate the impacts of an earthquake. This includes the lowlands of San Anselmo downtown and along its creek beds, where the risk of subsidence and subsequent earthquake shaking are higher. Future development in these areas could expose more people and infrastructure to earthquake shaking as a result of climate change.
2.2.5 FLOODING
Flooding is the rising and overflowing of a body of water onto normally dry land. Floods are among the costliest natural disasters in terms of human hardship and economic loss nationwide.
The area adjacent to a channel is the floodplain. Floodplains are illustrated on inundation maps, which show areas of potential flooding and water depths. In its common usage, the floodplain most often refers to that area that is inundated by the 100-year flood, the flood that has a one percent chance in any given year of being equaled or exceeded. The 100-year flood is the national minimum standard to which communities regulate their floodplains through the National Flood Insurance Program. The 200-year flood is one that has 0.5% chance of being equaled or 34 An Enhanced Seismic Activity Observed Due to Climate Change: Preliminary Results from Alaska. https://iopscience.iop.org/article/10.1088/1755-1315/167/1/012018 986
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exceeded each year. The 500-year flood is the flood that has a 0.2 percent chance of being equaled or exceeded in any given year. The potential for flooding can change and increase through various land use changes and changes to land surface, which result in a change to the floodplain. A change in environment can create localized flooding problems inside and outside of natural floodplains by altering or confining natural drainage channels. These changes are most often created by human activity such as construction of bridges or channels. In areas where flow contains high sediment load, such as Easkoot Creek in Stinson Beach (due to an active landslide upstream), the flow carrying capacity of the channel may be reduced dramatically during a single flood event. Coastal floodplains may also change over time as waves and currents alter the coastline (especially wetlands) and sea levels rise.
Flooding can occur in several ways:
Riverine flooding – Riverine flooding, defined as when a watercourse exceeds its “bank-full” capacity, generally resulting from prolonged rainfall, or rainfall that is combined with snowmelt and/or already saturated soils from previous rain events. This type of flood occurs in river systems whose tributaries may drain large geographic areas and include one or more independent river basins. The onset and duration of riverine floods may vary from a few hours to many days and is often characterized by high peak flows combined with a large volume of runoff. Factors that directly affect the amount of flood runoff include precipitation amount, intensity of rainfall and distribution of overland flow, the amount of soil moisture, seasonal variation in vegetation, snow depth, and water-resistance of the surface due to urbanization and geomorphology. In the Marin County OA, riverine flooding can occur anytime from November through April and is largely caused by intense and continued rains, sometimes combined with snowmelt, increased discharges from upstream dams, and intense flow from tributary streams.
These intense storms can overwhelm the local waterways as well as the integrity of flood control structures such as culverts and bridges. Flooding is more severe when antecedent rainfall has resulted in saturated soil conditions. The warning time associated with slow rise riverine floods assists in life and property protection.
Flash flooding – Flash flooding describes localized floods of great volume and short duration.
This type of flood usually results from a heavy rainfall on a relatively small drainage area.
Precipitation of this sort usually occurs in the winter and spring. Flash floods often require immediate evacuation within the hour and thus early threat identification and warning is critical for saving lives.
Localized/Stormwater flooding – Localized flooding problems are often caused by flash flooding, severe weather, or an unusual amount of intense rainfall. Flooding from these intense weather events usually occurs in areas experiencing an increase in runoff from impervious surfaces associated with development and urbanization as well as inadequate storm drainage systems.
Tidal flooding – Tidal flooding develops when high tides exceed either the top of bank elevation of tidal sloughs and channels, or the crest of bay levees. An especially high tide event that occurs during alignment of the gravitational pull between the sun and the moon, causing tidal water levels to rise to higher-than normal levels. King tides are normal, predictable events that occur semi-annually during winter months. Typically storms in which high tides coincide with peak stormwater flow may be damaging to municipal infrastructure and private property. 987
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The area is also at risk of flooding resulting from levee failures and dam failures. Dam failure flooding is discussed separately in the Dam Failure Section of this document; levee failure flooding is discussed separately in the Levee Failure Section of this document. Regardless of the type of flood, the cause is often the result of severe weather and excessive rainfall, either in the flood area or upstream reach.
A weather pattern called the “Atmospheric River” contributes to the flooding potential of the area.
An Atmospheric River brings warm air and rain to the West. A relatively common weather pattern brings southwest winds to the Pacific Northwest or California, along with warm, moist air. The moisture sometimes produces many days of heavy rain, which can cause soil saturation, extensive flooding and other impacts such as landslides. The warm air also can melt the snowpack in the mountains, which further aggravates the flooding potential. In the colder parts of the year, the warm air can be cooled enough to produce heavy, upslope snow as it rises into the higher elevations of the Sierra Nevada or Cascades. Forecasters and others on the West Coast often used to refer to this warm, moist air as the “Pineapple Express” because it comes from around Hawaii where pineapples are grown.
A diagram of an atmospheric river event is shown in Figure 28.
Figure 534: Diagram of an Atmospheric River Event
Source: NOAA
The Marin County OA is susceptible to various types of flood events. In coastal areas, flooding may occur when strong winds or tides result in a surge of seawater into areas that are above the normal high tide line. Other types of flooding in Marin include isolated ponding and stormwater overflow. Isolated ponding is when pools form on the ground and can occur in any area that doesn’t drain effectively – for example, in a natural depression in the landscape.
Stormwater overflow is when storm drains back up. Stormwater drainage systems quickly convey rainwater through underground pipes to creeks and the Bay. When the stormdrains are obstructed or broken or when the water bodies to which they lead to are already full, water 988
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backs up onto the streets. Although stormwater overflow and isolated ponding also occur throughout the County, the effects are typically not widespread or significantly damaging.
Flooding in San Anselmo generally results from creek flooding, and downtown San Anselmo will often flood in high rain events. San Anselmo is not located along the Coast and would not experience coastal flooding. San Anselmo is subject to periodic flooding from San Anselmo and Sleepy Hollow Creeks. The low-lying areas of San Anselmo and its neighboring communities have experienced widespread flooding throughout history as creeks overflow their banks. Ross Valley, where San Anselmo is located, is naturally prone to flooding by its location, geologic and geomorphic setting: rainfall can be intense, soils are shallow with limited absorption capacity, slopes are steep, stream channels are entrenched and in many places narrow with relatively little storage capacity. The watershed has been altered from its natural condition and many sections of creeks and streams have been placed in culverts and the natural pattern of runoff has been changed. During prolonged and heavy storms the watershed can become saturated. If rainfall is sufficiently intense, heavy runoff can result in high flows exceeding the capacity of the creek in places where conveyance is constrained. Floodwaters escape the creek capacity and breach the creek bank in downtown San Anselmo. ‘Localized’ flooding also occurs in many places in San Anselmo and is exacerbated where the storm water drainage network has inadequate capacity for peak flows or is blocked from sediment, debris, or vegetation. Localized flooding is characterized by excessive ponding in the street, and overflow onto lower-lying residential properties even during 5-year storm events. Localized flooding can occur within or outside of the FEMA designated floodplain. One example of localized flooding within the floodplain is Bolinas Avenue, on the border with the Town of Ross. Because the historic flow path has been severed, ponding occurs in the street during most large storms. When regional flooding occurs water flows down San Anselmo Avenue and connects to Bolinas and Shady Lane. Severe winter storms can also be accompanied by hazards and destruction resulting from high winds. High winds knock down limbs or entire trees which subsequently damage power and utility lines, buildings, block streets, and even pose a direct risk to human safety.
Local flooding in San Anselmo is exacerbated where the storm water drainage network has inadequate capacity for peak flows. The 100-year floodplain extends primarily west of San Anselmo Creek up to 1,000 feet in some areas up to Center Boulevard and extending up to 500 feet along both sides of the Creek past Center Boulevard to the boundary of Fairfax. An area of the 100-year floodplain extends north of Sir Francis Drake Boulevard near Butterfield Road for several hundred feet. The 500-year floodplain occurs primarily along the 100-year floodplain fringe, extending up to 1,000 feet south of Center boulevard in the middle of town and several hundred feet north of Sir Francis Drake Boulevard through San Anselmo Memorial Park. There are hundreds of homes, all of the downtown commercial area of San Anselmo, the St. Anselmo School, the San Anselmo Town Hall, the San Anselmo Emergency Operations Center, both of the San Anselmo Fire Department stations, the Archie Williams High School and part of the Brookside Elementary School that lie in the 100-year floodplain. Part of Sir Francis Drake Boulevard and Center Boulevard also lie in the 100-year floodplain. The Chronos Academy and parts of Sir Francis Drake Boulevard and Center Boulevard lie in the 500-year floodplain.
The most flood-prone areas San Anselmo are west of Sir Francis Drake near downtown, and along Sleepy Hollow Creek from the confluence upstream to the Fire Station #20. Main breakout points are where man-made obstructions, such as retaining walls, bridges, and buildings obstruct the flow of water. The deepest and most widespread flooding occurs in the area around downtown San Anselmo. At its upstream extent, floodwater jumps the bank at Nokomis and Madrone Avenues and heads through properties and towards Sycamore Ave. As San Anselmo Creek enters downtown San Anselmo it is constricted by the series of Building Bridges 989
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downstream of Bridge Avenue. The creek’s capacity here is approximately 2,800cfs, which is approximately the discharge of the 20 percent annual chance flood When discharge exceeds this capacity, floodwaters overtop and escape the banks of the creek, flooding the downtown business and residential district. During large floods, these floodwaters eventually reach the floodplain in Ross where they continue to flow through the downtown business and residential district there before continuing farther downstream through the unincorporated community of Kentfield. Floodwaters return to the channel near the College of Marin in lower Kentfield. 990
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Figure 535: Town of San Anselmo Flooding Critical Facilities and Infrastructure Source: Marin County OEM
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Numerous businesses, residential neighborhoods, schools, churches, community centers, roads, and other critical facilities lie in this area and are susceptible to flooding. San Anselmo has approximately 60 structures within the Floodway and approximately 562 within Special Flood Hazard Areas. Table 17 shows the number of San Anselmo critical facilities by flood zone.
Table 17: Town of San Anselmo Critical Facilities by Flood Zone Category Name Address Flood
Zone
1. Fire Fire: Ross Valley Fire
Department (RVY) / Station 19
777 San Anselmo Avenue
San Anselmo, CA 94960 AE
2. Fire Fire: Ross Valley Fire
Department (RVY) / Station 20
150 Butterfield Road
San Anselmo, CA 94960 AE
3. Law Central Marin Police 525 San Anselmo Avenue
San Anselmo, CA 94960 AE
4. Local
Government San Anselmo Town Hall 525 San Anselmo AvenueSan Anselmo, CA 94960 AE
5. Community
Center
Isabel Cook Community Center
(ICC)
1000 Sir Francis Drake Blvd.
San Anselmo, CA 94960 X
6. Library San Anselmo Public Library 110 Tunstead Ave. San Anselmo, CA 94960 AE
7. School Brookside Elementary School 116 Butterfield Road San Anselmo, CA 94960 AE/X
8. School Wade Thomas Elementary
School
150 Ross Avenue
San Anselmo, CA 94960 X
9. School St. Anselmo School 40 Belle Avenue
San Anselmo, CA 94960 AE
10. School Archie Williams High School 1327 Sir Francis Drake San Anselmo, CA 94960 AE/X
11. School Parkside Preschool and Daycare 1000 Sir Francis Drake Blvd.
San Anselmo, CA 94960 X
12. School University of Redlands 105 Seminary Road
San Anselmo, CA 94960 AE/X
Table 265: Town of San Anselmo Critical Facilities in the Flood Zones Source: County of Marin/FEMA DFIRM
Floodwaters can be deep enough to drown people and move fast enough to sweep people and vehicles away, lift buildings off foundations, and carry debris that smashes into buildings and other property. Flood waters can cause significant erosion which can lead to slope instability, severely damaging transportation and utility infrastructure by undermining foundations or washing away pavement. If water levels rise high enough to get inside buildings, flooding can cause extensive damage to personal property and the structure itself. Flood events that develop very quickly are especially dangerous because there may be little advance warning. A failure of the Phoenix Lake Dam or a breach and/or overtopping of the levees along San Anselmo Creek could contribute to flooding in the lowland areas of San Anselmo.
Floods in the San Anselmo develop rapidly, generally within 24 to 36 hours after the beginning of the flood-producing storm but are short in duration. Flood conditions usually subside within 24 hours. Floods in San Anselmo usually occur during large storm events. Typical winter peak discharges have been measured below 3,500 cfs. The two most severe floods occurred in the winters of 1982 and 2005, with peak discharges of approximately 7,200 cfs and 6,800 cfs, 992
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respectively. The 1982 flood was a 150-year event and the 2005 flood was approximately a 100-year event.
There is a long history of flooding in San Anselmo. The two most severe foods occurred in the winters of 1982 and 2005 (see below). Prior to establishment of the USGS stream flow gauging station in Ross on Corte Madera Creek in February 1951, flooding was reported in calendar years 1914, 1925, 1937, and 1942. Since the Ross gage has been in operation, flood flows have been recorded in 1951, 1955, 1958, 1967, 1969, 1970, 1982, 1983, 1986, 1994 (flooding was reported, but the stream flow gage was not in operation), and 2005. Town resolutions indicate a State flood relief was requested in 1957 and 1973. San Anselmo declared a local emergency for a flood of 3:00 a.m. on January 12, 1973. The flood in December 2005 - January 2006, was a federally declared disaster DR-1628. Seven inches of rain fell on the Ross Valley Watershed in the two weeks prior to the 2005 flood. Because of this near saturated condition, the earth had little or no capacity to absorb storm water on December 31, 2005. At 2:00 am on December 31, 2005, Corte Madera Creek was already at flood stage of 19 feet. The strongest part of the storm occurred from 3:00 am to 6:00 am. Flood waters topped the banks at Ross and San Anselmo creeks at the same time. The flood crested at 22.5 feet, 3.5 feet above flood stage at Ross.
In 2017, several rain events caused flooding in San Anselmo. On 2/7/2017, a powerful atmospheric river event caused flooding to several neighborhoods (see Figure 30.) Figure 536: February 2017 Flood in San Anselmo
Source: Marin Independent Journal
December 2005 was the wettest December in San Anselmo in over 50 years. On 12/31/2005- 1/1/2006, an atmospheric river event caused San Anselmo Creek to overflow its banks. More than four feet of water rushed down San Anselmo Avenue downtown. Town facilities include the police department, library, council chambers and fire department were damaged as well as 140 businesses and 290 homes. Damage was estimated at $30 million. The San Anselmo library lost around 1,000 books.
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Figure 537: 2005 Flood in San Anselmo
Source: San Anselmo History Museum
On 1/3–1/5/1982, a severe storm caused serious flooding damage in San Anselmo.
Floodwaters were three-four feet deep on San Anselmo Boulevard, essentially turning it into a river (see Figure 32.) All the commercial buildings in the downtown area suffered water damage, with damages estimated at $4 million. One house was destroyed, and thirty or more homes and thirty-forty businesses damaged. Utilities were out for several days and a curfew was enforced.
Figure 538: 1982 Flood in San Anselmo
Source: San Anselmo History Museum
Climate Change and Future Development Considerations
Climate change is expected to affect California's precipitation patterns, which are likely to influence future flood events. A 2017 study35 found that the number of very intense precipitation days in California is projected to more than double by the end of the century, increasing 117 percent, making it likely that flood events will become more frequent in the Marin County OA including San Anselmo. Climate change is expected to alter rainfall patterns in Northern California, including the Marin County OA. As the climate warms, rain events are predicted to become more intense. The Marin County OA including San Anselmo will likely experience more 35 Precipitation in a Warming World: Assessing Projected Hydro-Climate Changes in California and other Mediterranean Regaions. https://www.nature.com/articles/s41598-017-11285-y 994
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rain inundation events that lead to flooding and increase the potential threat of dam and levee failure, tree mortality, and other potential hazards. Future development in these areas will expose more people and infrastructure to the effects of flooding. Development along San Anselmo Creek and Sleepy Hollow Creek would expose more people, structures and infrastructure including major roads to creek flooding as a result of climate change. Flooding in downtown San Anselmo would continue to worsen with climate change.
2.2.6 LAND SUBSIDENCE
Land subsidence is a gradual settling or sudden sinking of the Earth's surface owing to subsurface movement of earth materials. The principal causes are aquifer-system compaction, drainage of organic soils through groundwater pumping, underground mining, hydrocompaction, natural compaction, sinkholes, and thawing permafrost. More than 80 percent of the identified subsidence in the United States is a consequence of underground water exploitation. The increasing development of land and water resources threatens to exacerbate existing land-subsidence problems and initiate new ones.
Sinkholes can form in three primary ways. Dissolution sinkholes form when dissolution of the limestone or dolomite is most intensive where the water first contacts the rock surface.
Aggressive dissolution also occurs where flow is focused in preexisting openings in the rock, such as along joints, fractures, and bedding planes, and in the zone of water-table fluctuation where groundwater is in contact with the atmosphere. See Figure 33 for a picture and description of how dissolution sinkholes form.
Figure 539: Dissolution Sinkhole Formation
Source: USGS
Cover-subsidence sinkholes tend to develop gradually where the covering sediments are permeable and contain sand. In areas where cover material is thicker, or sediments contain more clay, cover-subsidence sinkholes are relatively uncommon, are smaller, and may go undetected for long periods. See Figure 34 for a picture and description of how coversubsidence sinkholes form. 995
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Figure 540: Cover-Subsidence Sinkhole Formation
Source: USGS
Cover-collapse sinkholes may develop abruptly over a period of hours and cause catastrophic damages. They occur where the covering sediments contain a significant amount of clay. Over time, surface drainage, erosion, and deposition of sediment transform the steep-walled sinkhole into a shallower bowl-shaped depression. See Figure 35 for a picture and description of how cover-collapse sinkholes form.
Figure 541: Cover-Collapse Sinkhole Formation
Source: USGS
New sinkholes have been correlated to land-use practices, especially from groundwater pumping and from construction and development practices that cause land subsidence.
Sinkholes can also form when natural water-drainage patterns are changed and new waterdiversion systems are developed. Some sinkholes form when the land surface is changed, such as when industrial and runoff-storage ponds are created. The substantial weight of the new material can trigger an underground collapse of supporting material, thus causing a sinkhole.
The overburden sediments that cover buried cavities in the aquifer systems are delicately balanced by groundwater fluid pressure. The water below ground helps to keep the surface soil in place. Groundwater pumping for urban water supply and for irrigation can produce new sinkholes in sinkhole-prone areas. If pumping results in a lowering of groundwater levels, then underground structural failure, and thus, sinkholes, can occur.
Land subsidence and sinkholes would most likely occur in the central lowland areas of San Anselmo along San Anselmo Creek where the ground is more porous. This includes the primary commercial area of town there are numerous residences and critical facilities. Land 996
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subsidence could have numerous impacts for San Anselmo, including the settling of businesses and homes as well as the shifting of roadways and utility infrastructure that run through the Town.
On 4/12/2022, a sinkhole developed on Center Boulevard at San Anselmo Avenue and Sycamore Boulevard. The hole was about 3 to 4 feet near the surface and was possibly caused by a failed corrugated metal pipe under the street.
Figure 542: 2022 San Anselmo Sinkhole
Source: Marin Independent Journal
Climate Change and Future Development Considerations
Climate change could indirectly influence land subsidence as more severe and prolonged periods of drought may encourage more groundwater withdrawals. The rate of land subsidence could increase across the Marin County OA including the lowland areas of San Anselmo as a result of climate change. The impacts of land subsidence on infrastructure, including roads and underground utilities, in San Anselmo could increase with future development in the lowland populated areas of the city, particularly downtown, where land subsidence is more likely to occur.
2.2.8 SEVERE WEATHER – EXTREME HEAT
Extreme heat is defined as temperatures that hover 10 degrees or more above the average high temperature for the region and last for several weeks. A heat wave is an extended period of extreme heat, often with high humidity. When relative humidity is factored in, the temperature can feel much hotter as reflected in the Heat Index (see Figure 37):
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Figure 543: Heat Index
Source: NOAA
Heat kills by taxing the human body beyond its abilities. In a normal year, about 1,300 Americans succumb to the demands of summer heat. Heat is the leading weather-related cause of mortalities in the US. In 2006, California reported a high of 204 heat related deaths, with 98 reported in 2017 and 93 deaths reported in 2018.
Extreme heat has the potential to impact all areas of San Anselmo and would be felt more at lower elevations in the central areas of the Town. Temperatures can feel warmer in this area due to the widespread presence of concrete and asphalt, which stores heat longer. Heat waves can cause power outages and can sicken people who are exposed to high temperatures too long, particularly infants and the elderly.
In September 2022 the Marin County OA including the Town of San Anselmo experienced an Extreme Heat Event with temperatures exceeding 113 degrees.
Climate Change and Future Development Considerations
The primary effect of climate change is warmer average temperatures. The annual average daily high temperatures in California are expected to rise by 2.7°F by 2040, 5.8°F by 2070, and
8.8°F by 2100 compared to observed and modeled historical conditions. At the current rate, annual average temperatures in the Marin County OA region and Bay Area will likely increase by approximately 4.4 degrees by 2050 and 7.2 degree by the end of the century unless significant efforts are made to reduce greenhouse emotions according to California’s latest climate change assessment.
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Figure 544: Annual Average Temperatures in the San Francisco Bay Area, 2000-2100 Source: California Climate Change Assessment (Fourth Edition) As climate change accelerates in the 21st century, it is anticipated that extreme heat events will become more frequent and intense across the Marin County OA including in San Anselmo.
There will be increased residential and business needs for cooling and addressing heat-related issues. These effects would primarily be felt in the lowland areas of San Anselmo where heat builds in developed areas. Heat waves also tax the energy grid. Future development in the Marin County OA including San Anselmo could exacerbate the impacts from heat related events, particularly in electricity provision and water delivery. Increased temperatures will also lead to an increase in the occurrence and severity of wildfires across the Marin County OA including San Anselmo as conditions become hotter and drier. These effects will primarily be felt in the mountainous areas of San Anselmo where hotter and drier conditions are more apt to lead to wildfires. Future development near the many open spaces around San Anselmo could expose more people and infrastructure to the threat of a major wildfire as a result of increasing temperatures.
2.2.9 SEVERE WEATHER – HIGH WIND & & TORNADO
High Wind
High wind is defined as a one-minute average of surface winds 40 miles per hour or greater lasting for one hour or longer, or winds gusting to 58 miles per hour or greater regardless of duration that are either expected or observed over land. These winds may occur as part of a seasonal climate pattern or in relation to other severe weather events such as thunderstorms.
The Beaufort scale is an empirical measure that relates wind speed to observed conditions on land and is a common measure of wind intensity (see Figure 39).
Windstorms in the Marin County OA are typically straight-line winds. Straight-line winds are generally any thunderstorm wind that is not associated with rotation (i.e., is not a tornado). It is these winds, which can exceed 100 mph, which represent the most common type of severe weather and are responsible for most wind damage related to thunderstorms. 999
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Figure 545: Beaufort Wind Scale
Source: NOAA
Tornado
Tornadoes are rotating columns of air marked by a funnel-shaped downward extension of a cumulonimbus cloud whirling at destructive speeds of up to 300 mph, usually accompanying a thunderstorm. Tornadoes are the most powerful storms that exist, and damage paths can be in excess of one mile wide and 50 miles long. The Enhanced Fujita Scale (see Figure 40) is commonly used to rate the intensity of tornadoes in the United States based on the damages that they cause.
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Figure 546: Enhanced Fujita Scale
Source: NOAA
Tornadic waterspouts are tornadoes that form over water or move from land to water. They have the same characteristics as a land tornado. They are associated with severe thunderstorms, and are often accompanied by high winds and seas, large hail, and frequent dangerous lightning.
Figure 547: Waterspout Formation
Source: MarineInsights
All of San Anselmo is susceptible to storms and damage from wind and tornadoes, as most of the Town has tree cover. Drought can increase the susceptibility of trees toppling over in a high wind event. Fallen trees could damage homes and other facilities. Power lines could be impacted by fallen trees and wind, causing power outages. Roadways could also become blocked by fallen trees, affecting the ability of residents to reach their homes. 1001
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San Anselmo has experienced winter storms that have caused damage.
On 3/21/2023, powerful winds and rain caused numerous large trees to fall across San Anselmo, some falling on and damaging houses.
On 2/14/2019, a large tree was blown onto power lines near a Butterfield Road home in San Anselmo during a storm. The tree tilted toward the house and forced traffic restrictions.
San Anselmo has never experienced a tornado.
Climate Change and Future Development Considerations
It is anticipated that the atmospheric rivers that deliver storms to Northern California may intensify because of climate change. This increase in storm intensity may bring more intense winds and potential tornados to Northern California, including the Marin County OA and San Anselmo. Significant wind events and tornados can topple trees, particularly those that may be saturated, or drought stressed as a result of climate change. An increase in fallen trees in San Anselmo as a result of increased storms due to climate change can lead to an increase in power outages. Future development in any of the forested areas of San Anselmo with high tree cover including in the mountainous residential areas will increase the effects of severe wind events.
2.2.10 WILDFIRE
A wildfire is a fire that occurs in an area of combustible vegetation. The three conditions necessary for a wildfire to burn are fuel, heat, and oxygen. Fuel is any flammable material that can burn, including vegetation, structures, and cars. The more fuel that exists and the drier that fuel is, the more intense the fire can be. Wildfires can be started naturally through lightning or combustion or can be set by humans. There are many sources of human-caused wildfires including arson, power lines, a burning campfire, an idling vehicle, trains, and escaped controlled burns. On average, four out of five wildfires are started by humans. Uncontrolled wildfires fueled by wind and weather can burn acres of land and everything in their path in mere minutes and can reach speeds up to 15 miles per hour or faster depending upon wind speed and ember distribution. On average, more than 100,000 wildfires burn 4 to 5 million acres of land in the United States every year. Although wildfires can occur in any state, they are most common in the Western states including California where heat, drought, and thunderstorms create perfect wildfire conditions.
Wildfires are of primary concern when they occur in the Wildland Urban Interface (WUI), which is defined as areas where homes are built near or among lands prone to wildfire. Even relatively small acreage fires may result in disastrous damages. Most structures in the WUI are not destroyed from direct flame impingement, but from embers carried by wind. The damages can be widely varying, but are primarily reported as damage to infrastructure, built environment, and injuries to people.
The pattern of increased damages is directly related to increased urban spread into historical forested areas that have wildfire as part of the natural ecosystem and climate change. Many WUI fire areas have long histories of wildland fires that burned only vegetation in the past.
However, with new development, a wildland fire following a historical pattern may now burn these newly developed areas. WUI fires can occur where there is a distinct boundary between the built and natural areas or where development or infrastructure has encroached or is intermixed in the natural area. WUI fires may include fires that occur in remote areas that have 1002
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critical infrastructure easements through them, including electrical transmission towers, railroads, water reservoirs, communications relay sites or other infrastructure assets.
Consequently, wildland fires that burn in natural settings with little or no development are part of a natural ecological cycle and may actually be beneficial to the landscape. Century old policies of fire exclusion and aggressive suppression have given way to better understanding of the importance fire plays in the natural cycle of certain forest types.
Warning times are usually adequate to ensure public safety, provided that evacuation recommendations and orders are heeded in a timely manner. While in most cases wildfires are contained within a week or two of outbreak, in certain cases, they have been known to burn for months, or until they are completely extinguished by fall rains.
Wildfire poses the greatest risk to human life and property in the Marin County OA’s densely populated WUI, which holds an estimated 69,000 living units. The Marin County OA is home to 23 communities listed on CAL FIRE’s Communities at Risk list, with approximately 80% of the total land area in the county designated as having moderate to very high fire hazard severity ratings. The county has a long fire history with many large fires over the past decades, several of which have occurred in the WUI. To compound the issue, national fire suppression policies and practices have contributed to the continuous growth (and overgrowth) of vegetation resulting in dangerously high fuel loads. The Community Wildfire Protection Plan (CWPP) provides a scientifically based assessment of wildfire threat in the WUI of the Marin County OA.
Fire protection in California is the responsibility of either the federal, state, or local government depending upon the location of the incident. On federally owned land, or federal responsibility areas (FRA), fire protection is provided by the federal government, and or in partnership with local agreements. In state responsibility areas (SRA), CAL FIRE typically provides fire protection. However, in some counties CAL FIRE contracts with county fire departments to provide protection of the SRA – this is the case in the Marin County OA, where CAL FIRE contracts with Marin County Fire Department (MCFD). Local responsibility areas (LRA) include incorporated cities and cultivated agriculture lands, and fire protection is typically provided by city fire departments, fire protection districts, counties, and by CAL FIRE under contract to local government.
CAL FIRE contracts with MCFD to provide wildland fire protection and associated fire prevention activities for lands designated by the State Board of Forestry as SRA. The MCFD is responsible for the protection of approximately 200,000 acres of SRA within the county and is the primary agency that handles wildland fires. MCFD also provides similar protection services to approximately 100,000 acres of FRA in the Golden Gate National Recreation Area (GGNRA), the Muir Woods National Monument, and the Point Reyes National Seashore.
Figure 42 indicates the federal responsibility areas, state responsibility areas and local responsibility areas in the Marin County OA.
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Figure 548: Federal, State and Local Responsibility Areas in the Marin County OA Source: Marin Community Wildfire Protection Plan
The mix of weather, diverse vegetation and fuel characteristics, complex topography, and land use and development patterns in the Marin County OA are important contributors to the fire environment. The MCFD Woodacre Emergency Command Center (ECC) currently manages the data from four Remote Automated Weather Stations (RAWS) for predicting fire danger utilizing the National Fire Danger Rating System (NFDRS) during the fire season. The RAWS are located in Woodacre, Middle Peak, Barnabe, Big Rock and a new station will be coming online in Novato.
The Marin County OA is bounded by the cool waters of the Pacific Ocean to the west, the San Francisco and Richardson Bays to the southeast, the San Pablo Bay to the east, and Sonoma County agricultural lands to the north. The combination of these large bodies of water, location in the mid-latitudes, and the persistent high pressure over the eastern Pacific Ocean results in several micro-climates. Weather in the OA consists of warm, dry summers and cool, wet winters. The climate in early fall and late spring is generally similar to the summer, and late fall is similar to winter. Spring is generally cool, but not as wet as the winter. While these general weather conditions are fairly representative of the typical Marin County OA weather, complex topography, annual variability of weather patterns, and less frequent and transient weather patterns are important to fire conditions.
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In the late spring through early fall, the combination of frequent and strong high-pressure systems (known as the Pacific High) over California combined with the cool waters of the ocean/bays results in persistent fog and low clouds along the coast (including over the southern Marin County OA near the San Francisco Bay) with winds. The fog often penetrates into the inland valleys of the northern and central Marin County OA, especially during overnight hours.
At the coastline, mist from fog can keep the land surfaces modestly moist while inland land surfaces above the fog or inversion are often very dry.
The Pacific High that persists from late spring through early fall over the eastern Pacific, combined with a thermal low pressure over the Central Valley of California, results in an almost continuous sea breeze. These winds usher in cool and moist air and can be strong at times (15 to 25 mph), especially over the ridge tops and through northwest to southeast lying valleys, including San Geronimo/Ross, Hicks, Lucas Valleys, and Mill Valley and the Marin Headlands.
These westerly winds are usually highest in the afternoon, decrease in the evening, and are light overnight before increasing again in the late morning/early afternoon.
Occasionally in the summer and more often in the fall, the Pacific High moves inland and centers over Oregon and Idaho, while low pressure moves from the Central Valley of California to southern California and Arizona. The resulting north-to-south pressure gradient can be strong enough to retard the typical sea breeze and can even result in winds blowing from the land to the ocean (offshore winds). As the offshore winds move air from the Central Valley to the coastal areas of California, the air descends and compresses, which greatly warms and dries the air. Under these “Diablo” wind conditions, temperatures in the Marin County OA can reach 100°F in the inland areas and even 80°F at the coast, and relative humidity can be very low. In addition, wind speeds can be high (20 to 40 mph), gusty and are often much faster over the mountains and ridge tops such as Mt. Tamalpais, Loma Alta, Marin Headlands and Mt. Burdell compared to low-lying areas. Wind speeds can be high over the ridges and mountains at all times of day under this “offshore” wind pattern and are often much slower or even calm at night in low-lying areas because nighttime cooling decouples the aloft winds from the surface winds. It is during these Diablo wind events that there is a high potential for large, wind-driven fires should there be an ignition. Historically, the largest and most destructive fires have occurred during these offshore (also known as Foehn) wind events including the Angel Island and the Vision fires which were located in West Marin.
A few times per year in the summer and early fall, monsoonal flow from Mexico may bring in moist and unstable air over central and northern California, which can result in thunderstorms with or without precipitation. With the otherwise dry summer conditions, lightning from this type of weather pattern can ignite fires. These monsoonal flow patterns are usually only one to twoday events.
Beginning in late November and lasting through the end of March, the Pacific High moves south and weakens, allowing storms that originate in the Gulf of Alaska to move over California.
These storms bring precipitation and, at times, strong winds out of the south. Each storm usually results in one fourth inch to several inches of rain over a day or so. Near Mt. Tamalpais, rainfall amounts are enhanced by orographic lifting, resulting in higher rain amounts in the Kentfield and Fairfax areas compared to the rest of the county. Typically, after the first rain in November, the cool weather and occasional storm keeps the ground wet through late Spring.
However, in some years, significant rain does not occur until later in the year (e.g., early-to-late 1005
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December) and there can be several weeks without any storms and rain. During storms, temperatures are usually mild.
When there are no storms over California, a land-breeze typically forms (i.e., winds blowing from the Central Valley to the Pacific Ocean). These winds can reach 30 mph, and travel through the southeast to northwest lying valleys, over low-lying ridges such as the Marin Headlands, and through the Golden Gate. These winds are usually highest in the mid-morning hours and decrease in the afternoon as the Central Valley warms during the day. The winds are associated with cold and modestly moist air.
In late February/early March through late April, the Pacific High strengthens and moves north, and storms impacting the county become less frequent. During this time of year there is often a low-pressure area over the desert in southwest California. The combination of the Pacific High to the north and low-pressure to the southwest results in strong winds blowing from the northwest to the southeast. Like the sea breeze, these winds bring in cool, moist air and are usually highest in the afternoon hours. Because of winter and spring rains, the land is wet and there is little danger of wildland fire despite the strong winds and only occasional precipitation.
There is often little coastal fog this time of year.
Vegetation, which is also known as fuel, plays a major role in fire behavior and potential fire hazards. A fuel’s composition, including moisture level, chemical make-up, and density, determines its degree of flammability. Of these, fuel moisture level is the most important consideration. Generally, live trees contain a great deal of moisture while dead logs contain very little. The moisture content and distribution of fuels define how quickly a fire can spread and how intense or hot it may become. High moisture content will slow the burning process since heat from the fire must first eliminate moisture.
In addition to moisture, a fuel’s chemical makeup determines how readily it will burn. Some plants, shrubs, and trees such as chamise and eucalyptus (both present in the Marin County OA) contain oils or resins that promote combustion, causing them to burn more easily, quickly, and intensely.
Finally, the density of a fuel influences its flammability; when fuels are close together but not too dense, they will ignite each other, causing the fuel to spread readily. However, if fuels are so close that air cannot circulate easily, the fuel will not burn freely.
The Marin County OA has extensive topographic diversity that supports a variety of vegetation types. Marin County’s OA has significant changes in topography with steep vegetated slopes which can also add to the ability of the fuel to further expand a wildfire.
Environmental factors, such as temperature, precipitation, soil type, aspect, slope, and land use history, all help determine the existing vegetation at any given location. In the central and eastern parts of the county, north facing slopes are usually densely wooded from lower elevations to ridge peaks with a mixture of mostly hardwood tree species such as coast live oak, California bay, Pacific madrone, and other oak species. Marshlands are also present throughout the county; once ignited marsh fires can be difficult to contain and extinguish.
Grasslands with a mixture of native and nonnative annual and perennial plant species occur most often in the northern and western parts of the county due to a combination of soil type, lower rainfall, and a long history of ranching. The southern and western facing slopes tend to 1006
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have a higher percentage of grasslands, which in turn have the potential to experience higher rates of fire spread. Grassland fires are dangerous even without extreme fire weather scenarios due to the rapid rate of fire spread; in some cases, fires spread so quickly that large areas can burn before response resources are able to arrive.
In the west portion of the county closer to the coast, where precipitation is higher and marine influence is greater, most areas are densely forested with conifer species (i.e., Bishop pine, Douglas-fir, and coast redwood) and associated hardwood species. Chaparral vegetation also occurs in parts of the county, especially on steeper south and west facing slopes. This mix of densely forested areas mixed with chaparral results in higher fuel loads and potentially higher fire intensity. Expansion of the residential community into areas of heavier vegetation has resulted in homes existing in close proximity to dense natural foliage; these homes are often completely surrounded by highly combustible or tall vegetation, increasing the potential that wildland fires could impact them.
As part of the development of the Marin Community Wildfire Protection Plan (CWPP), an updated vegetation map layer was created using the most recent vegetation information available from a variety of state and local data sources.
Vegetation distribution in the Marin County OA is characterized by approximately 20 different types of vegetation which have been classified into 15 fire behavior fuel models. 1007
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Figure 549: Fuel Model Map for the Marin County OA
Source: Unknown
Insect infestations and plant diseases, such as California oak mortality syndrome (sudden oak death), are increasing and threaten to change the structure and overall health of native plant communities in the Marin County OA. Sudden oak death has no known cure and is a concern since this specific disease can impact vegetation through Marin including the WUI; this syndrome is caused by the fungus-like Phytophthora ramorum, which has led to widespread mortality of several tree species in California since the mid-1990s; the tanoak (Lithocarpus densiflorus) in particular, appears to have little or no resistance to the disease. Sudden oak death has resulted in stands of essentially dead trees with very low fuel moistures.
Studies examining the impacts of sudden oak death on fire behavior indicate that while predicted surface fire behavior in sudden oak death stands seems to conform to a common fuel model already in use for hardwood stands, the very low moisture content of dead tanoak leaves may lead to crown ignitions more often during fires of “normal” intensity.
Two other plant diseases prevalent in the Marin County OA are pitch canker (which affects conifers such as Bishop pine and other pine species), and madrone twig dieback (which affects Pacific madrones). Pitch canker is caused by the fungus Fusarium circinatum (F. subglutinans, F. sp. pini), which enters the tree through wounds caused by insects. While some trees do recover, most infected trees are eventually killed by the fungus. Management of this disease 1008
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largely focuses on containment to reduce the fungus spreading to other trees. Pitch canker is a particular issue in the NPS lands of Pt. Reyes National Seashore, where many acres of young Bishop Pines that were seeded on the Inverness Ridge by the Mount Vision Fire of 1995 have been infected.
These dead and dying trees have created large swaths of land with dense and dry fuel loads.
Madrone twig dieback is caused by the native fungus Botryosphaeria dothidea and appears to be getting worse throughout the county due to drought effects on Pacific madrones. Three additional threats to trees common to the Marin County OA include:
• Bark and ambrosia beetles (Monarthrum dentiger and monarthrum scutellare), which target oak and tanoak trees. Sudden oak death may be exacerbating the effects of beetle infestations which prey on trees already weakened by this disease. • Root rot, caused by oak root fungus (Armillaria mellea), is primarily associated with oaks and other hardwoods but also attacks conifers. These fungal infestations cause canopy thinning and branch dieback and can kill mature trees. As with the beetle infestations, sudden oak death may be exacerbating the effects of root rot fungus in the county forests.
• Velvet-top fungus (Phaeolus schweinitzii) is a root rot fungus affecting Douglas-fir and other conifers, with the infection typically occurring through a wound.
Topography characterizes the land surface features of an area in terms of elevation, aspect, and slope. Aspect is the compass direction that a slope faces, which can have a strong influence on surface temperature, and more importantly on fuel moistures. Both elevation and aspect play an important role in the type of vegetation present, the length of the growing season, and the amount of sunlight absorbed by vegetation. Generally, southern aspects receive more solar radiation than northern aspects; the result is that soil and vegetation on southern aspects is warmer and dryer than soil and vegetation on northern aspects. Slope is a measure of land steepness and can significantly influence fire behavior as fire tends to spread more rapidly on steeper slopes. For example, as slope increases from 20 – 40%, flame heights can double and rates of fire spread can increase fourfold; from 40 – 60%, flame heights can become three times higher and rates of spread can increase eightfold.
The Marin County OA is topographically diverse, with rolling hills, valleys and ridges that trend from northwest to southeast. Elevation throughout the county varies considerably, with Mt.
Tamalpais’ peak resting at 2,574 feet above sea level and many communities at or near sea level. Correspondingly, there is considerable diversity in slope percentages. The San Geronimo Valley slopes run from level (in the valley itself) to near 70%. Mt. Barnabe has slopes that run from 20 to70%, and Throckmorton ridge has slopes that range in steepness from 40 – 100%.
These slope changes can make fighting fires extremely difficult.
In the WUI where natural fuels and structure fuels are intermixed, fire behavior is complex and difficult to predict. Research based on modeling, observations, and case studies in the WUI indicates that structure ignitability during wildland fires depends largely on the characteristics and building materials of the home and its immediate surroundings.
The dispersion of burning embers from wildfires is the most likely cause of home ignitions.
When embers land near or on a structure, they can ignite near-by vegetation or accumulated 1009
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debris on the roof or in the gutter. Embers can also enter the structure through openings such as an open window or vent and could ignite the interior of the structure or debris in the attic.
Wildfire can further ignite structures through direct flame contact and/or radiant heat. For this reason, it is important that structures and property in the WUI are less prone to ignition by ember dispersion, direct flame contact, and radiant heat.
Public Safety Power Shutoff (PSPS) Events
As a result of the 2017 Northern California Wildfires, the 2018 Camp Fire in Butte County and other wildfires caused by power line infrastructure, Pacific Gas & Electric (PG&E) began initiating Public Safety Power Shutoff (PSPS) events in their service areas (including the Marin County OA) to help prevent the start of future wildfires. PG&E will initiate a PSPS if conditions indicate potentially dangerous weather conditions in fire-prone areas due to strong winds, low humidity, and dry vegetation. During these events, PG&E will proactively turn off power in high fire risk areas to reduce the threat of wildfires. The most likely electric lines to be considered for a public safety power outage will be those that pass through areas that have been designated by the California Public Utilities Commission (CPUC) High Fire-Threat District at elevated (Tier 2) or extreme risk (Tier 3) for wildfire. Customers outside of these areas could have their power shut off, though, if their community relies upon a line that passes through a high fire-threat area or an area experiencing severe weather. PG&E will consider numerous factors and analyze historical data to help predict the likelihood of a wildfire occurring, and closely monitoring weather watch alerts from the National Weather Service (NWS). These factors generally include, but are not limited to:
• A Red Flag Warning declared by the National Weather Service • Low humidity levels, generally 20 percent and below
• Forecasted sustained winds generally above 25 mph and wind gusts in excess of approximately 45 mph, depending on location and site-specific conditions such as temperature, terrain and local climate
• Condition of dry material on the ground and live vegetation (moisture content) • On-the-ground, real-time observations from PG&E's Wildfire Safety Operations Center and field crews
Pacific Gas & Electric Company (PG&E) operates a total of 1,179 miles of overhead electricity transmission and distribution lines in the Marin County OA. Overhead electricity lines and poles can be damaged or downed under severe weather conditions, particularly severe wind conditions, which increases the potential for wildfire ignition. 52 percent of PG&E’s overhead distribution lines and 41 percent of its overhead transmission lines are located in CPUCidentified High-Fire Threat Districts subject to elevated or extreme fire risk. PG&E is currently planning and implementing safety measures to prevent wildfires and reduce the impacts of Public Safety Power Shutoff (PSPS) events on communities in the Marin County OA and throughout California.
In October 2019 the Marin County OA including the Town of San Anselmo experienced two PSPS events.
These measures include installing weather stations; installing high-definition cameras; installing sectionalizing devices on its overhead lines to separate the grid into smaller sections; hardening 1010
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the system by installing stronger power poles, covering lines, and undergrounding lines in targeted areas; creating temporary microgrids to provide electricity during PSPS events; and enhancing existing vegetation management activities. From 2018 to July 2021, PG&E hardened three miles of overhead lines, installed 68 transmission and distribution sectionalizing devices, completed enhanced vegetation management on approximately 51 of overhead line miles, installed 28 weather stations, and installed 12 high-definition cameras in the Marin County OA.
PG&E has also begun undergrounding several overhead transmission lines throughout California.
The fire season generally lasts from five to six months, when there is little rain. Access to the adjacent open space areas and the hillside and canyon areas is limited by few access routes and narrow roads. San Anselmo is within the Wildland-Urban Interface (WUI) and most of the town is in a moderate to high FHSZ. San Anselmo currently has approximately 2,243 homes, six Marin Municipal Water District (MMWD) water tanks and pump stations, the Ross Valley School District and three schools located in the WUI. The Town borders directly on the open space lands of the MMWD. The hillsides and canyons carry the potential of high fire danger. The potential of wild land fire is an extreme risk to all areas within the Town, not just hillside areas.
Many residences in the high wildfire threat areas were built prior to current fire codes and have siding and roofing that is not fire resistant. Residences may be surrounded by flammable vegetation. Certain areas of the Town have water pressure and water flow that do not meet current standards. There is limited water availability, water pressure, and water flow in certain areas within San Anselmo. The wildland fire hazard is caused by a combination of factors including hillside terrain, highly flammable vegetation and forest, long summers, and human activity. There are heavy fuel loads. Many homes have been built on steep slopes with vegetation in close proximity. The onset of Sudden Oak Death (SOD) has significantly increased the number of dead or weakened trees in the areas, which contributes to the fuel loads. Wind is a predominant factor in the spread of fire. 1011
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Figure 550: Town of San Anselmo Wildfire Critical Facilities and Infrastructure Source: Marin County OEM
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Wildfires can cause short-term and long-term disruption to San Anselmo. Fires may result in deaths and injuries and can destroy buildings and infrastructure. Additional costs associated with the loss of homes to wildland fire include disruption of utilities, transportation, and other public services. Although the physical damages and casualties arising from wildfires may be severe, it is important to recognize that they also cause significant economic impacts by resulting in a loss of function of buildings and infrastructure. In large wildfire events, the economic impact of this loss of services may be comparable to the economic impact of physical damages to the Town. Economic impacts of loss of transportation and utility services may include traffic delays/detours from road and bridge closures and loss of electric power, potable water, and wastewater services. Wildfires can also cause major damage to power lines needed to distribute electricity to operate facilities. High intensity wildfires can also have substantial effects on watersheds through loss of vegetation and soil erosion, which may impact the Town by changing runoff patterns, reducing water storage capacity of Phoenix Lake, and degrading water quality through sedimentation and contamination.
All of San Anselmo could be impacted by a Public Safety Power Shutoff (PSPS) event and/or suffer poor air quality from smoke as a result of a wildfire in the Marin County OA or the surrounding region. As wildland areas around San Anselmo become drier due to climate change, the risk of a wildfire occurring and impacting the Town will continue to increase. Brush fires in the Town may increase over time as parks and other open spaces experience drier conditions.
San Anselmo has never experienced a major wildfire. The Town experiences small fires annually but none since the last plan update.
In 1976, the Town experienced an approximately 100-acre fire at the end of San Francisco Boulevard, currently Sorich Park, which burned up towards Indian Rock. Two homes were lost.
Climate Change and Future Development Considerations
Climate change can lead to an increase in wildfire events. Climate change has been a key factor in increasing the risk and extent of wildfires in the western United States. Changes in climate create warmer, drier conditions. Increased drought, and a longer fire season are boosting these increases in wildfire risk.
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Figure 551: Trends in the Annual Number of Large Wildfires in the United States Source: Fourth Climate Change Assessment, 01/04/23
As summer conditions in Northern California become hotter and drier due to climate change, the occurrence and severity of wildfires will only increase. The Marin County OA including San Anselmo is particularly susceptible to these future impacts of climate change on wildfire, as the OA’s climate has generally been wet enough historically to avoid major wildfires. Extreme heat events and high wind events could cause electrical systems to become overloaded and fail, sparking wildfires. An increase in wildfires as a result of climate change could lead to more significantly burned areas that could contribute to debris flows after a significant storm event, particularly in the open space areas around San Anselmo. Future development in the WUI throughout San Anselmo will expose more people and property to the impacts of a potentially significant wildfire. The growing number of people in the San Anselmo WUI can increase risk to life, property and public health as a result of a wildfire. 1014
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SECTION 3.0: MITIGATION STRATEGY
3.1 CHANGES IN DEVELOPMENT
The County of Marin is a county located in the northwestern San Francisco Bay Area. As of the 2020 census, the population was 262,231. Its county seat and largest city is San Rafael. The Marin County OA is across the Golden Gate Bridge from San Francisco, and is included in the San Francisco–Oakland–Berkeley, CA Metropolitan Statistical Area.
The Town is approximately 2.68 square miles in size with a population of 12,623. The community is situated in the Ross Valley, bordered by steep hillside areas including the Mount Tamalpais Watershed, and located 20 miles north of San Francisco in Marin County. San Anselmo is a small, established residential community with visitor- and neighborhood-serving businesses centered on the major transportation thoroughfares, including Sir Francis Drake Boulevard, San Anselmo Avenue, and Red Hill Avenue. Winding streets emanate out from the major roadways into quiet, residential neighborhoods and steep hillsides. Historic Downtown San Anselmo, one of the major commercial centers in San Anselmo, sits at the heart of the town and follows San Anselmo Creek. Existing residential development in San Anselmo numbers approximately 5,567. These are predominantly single-family residences, with some accessory dwelling units on single-family properties, and some apartment units located near commercial corridors. In 2020, approximately 80 percent of homes were single family (4,174 single family detached units, and 266 single family attached units) and approximately 19 percent were multi-family units (358 units within duplexes, triplexes, or quadplexes and 683 units in developments of five or more units). There have been few multi-family developments since 2015; however, the Town has seen marked interest in accessory dwelling units in recent years.
The town is largely developed with most remaining land constrained by environmental hazards or conserved as open space. The beauty of the natural landscape helps define the character of the community, but it also presents risk of natural hazards that limit the potential for new housing, including steep topography and areas Furthermore, the community values the town’s close access to open space with its natural beauty and recreation opportunities. Therefore, new construction is predominantly limited to infill development.
San Anselmo’s Regional Housing Needs Assessment (RHNA) allocation for the 2023-2031 planning period has been determined by ABAG to be 833 housing units, including 253 units for very low-income households, 145 units for low-income households, 121 units for moderateincome households, and 314 units for above moderate-income households.
Table 18: Town of San Anselmo Future Growth Areas
Development # of
Units
# of
Parcels
Project
Date Acres
Fire
Severity
Zone
Flood
Zone
1 729 Sir Francis Drake Blvd 1 1 TBD1 0.09 No AE/X
2 1214 San Anselmo Ave 1 1 TBD1 0.02 No X
3 Vacant Lot - Sturdivant Ave 1 1 TBD1 0.31 No No
4 61 Hillside Ave 1 1 TBD1 0.22 Yes X
5 63 Hillside Ave 1 1 TBD1 0.21 Yes X
6 1 Saunders Ave 1 1 TBD1 0.11 No X
7 21 Santa Barbara Ave, Unit A 1 1 Underway 0.16 No X
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8 40 Sir Francis Drake Blvd, Unit A
1 1 TBD2 0.26 No AE/AE
FLOODWA
Y/X
9 1 The Alameda Knolls, Unit A 1 1 TBD2 0.65 Yes X
10 344 Oak Ave, Unit A 1 1 TBD2 0.46 Yes X
11 55 Avenue Del Norte, Unit A 1 1 TBD2 1.00 Yes X
12 101 Cedar St, Unit A 1 1 Underway 0.17 Yes X
13 112 Crescent Rd, Unit A 1 1 Underway 0.19 Yes X
14 22 Belle Ave 1 1 Underway 0.18 No AE
15 3 Ray Ct, Unit A 1 1 Underway 0.26 Yes X
16 9 Tomahawk Dr, Unit A 1 1 Underway 0.56 Yes X
17 15 Oak Springs Dr, Unit A 1 1 Underway 0.17 Yes X
18 20 Karl Ave, Unit A 1 1 Underway 0.13 No X
19 11 Hooper Ln, Unit A
1 1 Underway 0.16 No AE/AE
FLOODWA
Y/X
20 100 Berkeley Ave 1 1 Underway 0.14 Yes X
21 49 Cedar St 1 1 TBD2 0.26 Yes X
22 600 Red Hill Ave 18 1 TBD2 1.61 Yes X
23 65 Lincoln Park 1 1 TBD2 0.07 Yes X
24 43 Indian Rock Ct 1 1 TBD2 0.72 Yes X
25 72 Oak Knoll Ave 1 1 Underway 0.21 No X
26 55 Avenue Del Norte 1 1 Underway 1.00 Yes X
27 78 Longwood Dr 1 1 Underway 0.46 Yes X
28 16 Broadmoor Ave 1 1 Underway 0.13 No AE
29 268 Brookside Dr 1 1 Underway 0.12 Yes X
30 24 Ross Valley Dr 1 1 TBD2 0.21 No X
31 151 Los Angeles Blvd 1 1 TBD2 0.16 No AE/X
32 10 Humboldt Ave 1 1 TBD2 0.45 Yes X
33 53 Canyon Rd 1 1 TBD2 0.18 Yes X
34 88 Crooked Ave 1 1 TBD2 0.46 Yes X
35 16 Berkeley Ave 1 1 Underway 0.13 No X
36 316 Greenfield Ave 1 1 TBD2 0.22 No X
37 6 Spruce Ave 1 1 TBD2 0.22 Yes X
38 Total 54 37 n/a 12.06 n/a n/a
39 729 Sir Francis Drake Blvd 1 1 TBD1 0.09 No AE/X
40 1214 San Anselmo Ave 1 1 TBD1 0.02 No X
Total 54 37 n/a 12.06 n/a n/a
Table 266: Town of San Anselmo Future Growth Areas
Source: Town of San Anselmo
3.2 CAPABILITY ASSESSMENT
The overall priorities in the Town of San Anselmo have not changed since the 2018 MJHMP update. However, the strategies in which to support the overall town priorities have changed and are reflected in the sections below. There were many projects that were either ongoing day-to-day business activities or were response related that were completed or deleted from the 2018 MJHMP project list and not carried over to this plan update. Several actions were completed and new projects were added to coincide with the changes in priorities, progress in local mitigation efforts and changes in development.
Capabilities are the programs and polices currently in use to reduce hazard impacts or that could be used to implement hazard mitigation activities. The capability assessment identifies the 1016
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local planning mechanisms where information from the 2018 MJHMP is incorporated and where updated hazard mitigation information from this 2023 MJHMP will be incorporated once approved. The 2018 capability assessments have been successfully incorporated into the Town of San Anselmo General Plan to include the Public Safety Element, Land Use Element, and Housing Element and the 2023 capability assessments will also be incorporated into the General Plan and these Elements. The capability assessment is divided into four sections:
regulatory, administrative and technical, fiscal, and outreach and partnerships.
3.2.1 REGULATORY CAPABILITIES
The legal and regulatory capabilities include existing ordinances and codes that affect the Town’s physical or built environment. Examples of legal and/or regulatory capabilities can include: a jurisdiction’s building codes, zoning ordinances, subdivision ordnances, special purpose ordinances, growth management ordinances, site plan review, general plans, capital improvement plans, economic development plans, emergency response plans, and real estate disclosure plans. The table below lists regulatory mitigation capabilities, including planning and land management tools, typically used by local jurisdictions to implement hazard mitigation activities and indicates those that are in place.
Table 19: Town of San Anselmo Legal and Regulatory Capabilities Plans
Yes/No
Latest
Update
Does the plan/program address hazards?
Does the plan identify projects to include in the mitigation strategy?
Can the plan be used to implement mitigation actions?
General Plan/Master Plan Y
The Town’s General Plan outlines long-term direction for development and policy. It describes hazard areas and
regulates current and future development based on known hazard areas. The General Plan has been amended every
few years since 1975 and as this plan gets updated there is potential to improve it with updated risk information and strategies.
Strategic Plan Y
The Town’s strategic plan addresses flood control, a
resilient hub, and multi-model transportation, which
includes mitigation strategies and actions.
Capital Improvements Plan
Y
2019
This study describes plans and technical rationale for a suite of projects along the watershed that work together as a system to reduce flooding and seeks to restore the
ecological health and function of Corte Madera Creek and its tributaries.
Economic Development Plan
Y
2018
The goal of the Economic Development Plan is to provide specific Town actions to maintain and enhance the
economic viability of the Town’s Commercial area through actions that attract, retain and nurture local businesses consistent with General Plan goals to preserve the small town community
character, scale, and pace of life and the Town’s close connection with the natural beauty of its setting.
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Local Emergency Operations
Plan
Y
The plan identifies hazards and mitigation strategies for earthquakes, storms, fire, floods, landslides, airplane crashes, vehicle accidents and terrorism.
Continuity of Operations
Plan
N
Flood Mitigation Plan (FMP)
Y
2008
San Anselmo’s 2008 Flood Mitigation Plan provides a
glimpse of the Town’s response to the 2005/06 flood and the
mitigation options that were considered before the 2019 Capital Improvement Plan Study for Flood Damage
Reduction and Creek Management
Engineering Studies for
Streams
Y The Town’s 100-year flood mitigation plan with the County of Marin includes mitigation strategies and actions.
Open Space Management
Plan
Y
The Town has an Open Space Committee and a Sorich
Park Master Plan. Sorich Park is approximately 64 acres of open space in San Anselmo. Management of the park
strive to reduce fire and safety hazards, accommodate
existing reasonable uses, and reconcile the needs of the neighborhood and the community.
Regional Transportation
Plan (RTP) N Regional transportation plan completed by Transportation Authority of Marin
Stormwater Management
Plan/Program Y
The Town participates in Marin Countywide Stormwater
Pollution Prevention Program, MCSTOPPP.
Engineering Studies for
Streams Y The Town’s 100-year flood mitigation plan with the County of Marin includes mitigation strategies and actions.
Community Wildfire
Protection Plan Y The Town is part of the Marin County Wildfire Protection Plan, which includes mitigation strategies and actions.
Other special plans (e.g.,
brownfields redevelopment,
disaster recovery, coastal
zone management, climate
change adaptation)
Y
San Anselmo’s Climate Action Plan 2030 is a tool to
develop strategies and guide the implementation of local measurable actions needed to (1) mitigate climate change by dramatically reducing our greenhouse gas emissions
while also sequestering GHG from the atmosphere, and
(2) prepare for and adapt to increasing extremes and
impacts.
Building Code, Permitting,
and Inspections Y/N Are codes adequately enforced?
Building Code Y Yes, state and local building codes are adequately enforced.
Building Code Effectiveness
Grading Schedule (BCEGS)
Score
N
Fire department ISO rating: Y The Fire department has an ISO rating of 2. It is adequately enforced.
Site plan review
requirements Y
Site plans shall include: an outline of the lot showing the length and direction of all property lines; relevant property setbacks; all buildings, fences, retaining walls, walkways, and driveways. Clearly indicate the distances from any
structure to the property lines. Show all structures presently on the site and those proposed; indicate paving material for the driveway and if the paving is new or existing; a north 1018
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arrow; the edge of street pavement and name of any
abutting street; if a curb and/or sidewalk exists; site drainage; contour lines for properties steeper than a onefoot drop over a seven-foot horizontal distance (15% grade).
Land Use Planning and
Ordinances Y/N
Is the ordinance an effective measure for reducing
hazard impacts?
Is the ordinance adequately administered and enforced?
Municipal Code Y
The Municipal Code includes several sections that address hazard mitigation. The Town adopts the current California Building Code which applies to all construction activity within the Town boundaries and supports earthquake and fire
mitigation.
Watercourse Protection and Floodplain Development are
sections that protect against worsening flood situations.
The Municipal code is updated periodically to improve
mitigation efforts.
Zoning ordinance Y
The Zoning Ordinance implements the General Plan by
establishing specific regulations for development. It includes standards for where development can be located, how
buildings must be sized, shaped, and positioned, and what types of
activities can occur in an area. Mitigation actions that pertain to new or substantially redeveloped buildings can be
adopted into the Zoning Ordinance.
Subdivision ordinance Y
Title 10, Chapter 2 (Subdivisions). In addition, Title 10, Chapter 4 (Housing Developments Under Government
Code Section 65852.21) establishes a ministerial review process and provide objective zoning standards for TwoUnit Developments and Urban Lot Splits.
Floodplain ordinance Y
Title 7, Chapter 11 Protection of Flood Hazard Areas is an effective measure for reducing the impact to structures located in the AE floodplain and AE floodway. The
ordinance is enforced by Building and Public Works
Departments.
Natural hazard specific
ordinance (stormwater,
steep slope, wildfire)
Y
Title 9, Chapter 1, 9-1.214 Exterior Fire Resistive
Construction reduces the impacts of fire through the
hardening of structures in the identified Wildland Urban Interface (WUI) or otherwise known as High Fire Severity Zones. Ordinance 9-1.215 Outside opening protection
Section R303.6 reduces the impacts of fire on structures in all of San Anselmo. Title 5, Chapter 8, 5-8.11 Limitation of Impervious Surfaces, Flatwork Permits and PostConstruction Requirements effectively reduces impervious surfaces and requires bioretention or
permanent stormwater controls to remove sediment and
other pollutants from entering the stormwater runoff.
These ordinances are enforced by Building and Public
Works Departments.
Flood insurance rate maps Y
Title 7, Chapter 11 Protection of Flood Hazard Areas
establishes the areas of special flood hazards identified by the Federal Emergency Management Agency
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(FEMA), with accompanying Flood Insurance Rate Maps
(FIRMs) adopted by reference and declared to be a part
of the Municipal Code. These maps are used by the
Planning, Building, and Public Works Departments to
identify flood hazards
Elevation Certificates Y
Title 10, Chapter 4, 10-4.301 Administration, all projects located in a special flood hazard area are required to
provide an elevation certificate for the structure. The ordinance is enforced by the Building Department. The
ordinance effectively identifies structures in the special flood hazard area as well as identifies how the structures either comply with the Town’s flood ordinance or how the structures need to be altered to comply with the Flood
ordinance.
Acquisition of land for open
space and public recreation
uses
N
Erosion or sediment control
program
Y
Title 5, Chapter 8, Urban Runoff Prevention is to ensure the future health, safety, and general welfare of Town
of San Anselmo citizens and to protect and enhance
watercourses, fish, and wildlife habitat by:
a. minimizing discharges other than storm runoff into
drains and watercourses.
b. Responding to the discharge of spills, preventing
and controlling the discharge of spills to storm
drains or watercourses, and prohibiting dumping or
disposal of materials other than stormwater;
c. Reducing pollutants in stormwater discharges to the
maximum extent practicable;
d. Requiring operators of construction sites, new or
redeveloped land, and industrial and commercial
facilities to install, implement, and maintain
appropriate best management practices (BMPs);
and
e. Requiring development projects to maintain or
reduce the volume, velocity, peak flow rate, and
duration of runoff as compared to the predevelopment stormwater runoff rates; and preventing stormwater pollution whenever possible,
through stormwater management controls and
ensuring that these management controls are
properly maintained.
Title 9, Chapter 18, Excavation, Grading and Erosion
Control, establishes controls on excavation, grading, and fill within the town. The controls are enforced by the
Planning, Building, and Public Works Departments. The
ordinance requires work proposing movement of 25 or
more cubic yards of soil to obtain a permit to protect
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protection. In addition, the ordinance restricts work
during the rainy season (from October 15th to April 15th).
Table 267: Town of San Anselmo Legal and Regulatory Capabilities Source: Town of San Anselmo
Town of San Anselmo General Plan or Master Plan
California Government Code 65300 requires that every Town and County in the state have a General Plan. The Town of San Anselmo General Plan, adopted in 1975 and most recently amended in 2019, included an extensive public review process. The General Plan is the most important policy and planning document in the Town and is used by virtually every department.
The General Plan is the Town's statement of its vision for the future. The General Plan contains policies covering every aspect of the Town: land use (how land can be developed), circulation, noise, air quality, housing, open space and conservation, and health and safety.
Town of San Anselmo specific goals and policies related to mitigation of natural hazards are as follows:
Table 20: Town of San Anselmo General Plan
Goal/Policy/
Program Explanation
Land Use Element
Goals
LU 3. New developments shall be integrated harmoniously into San Anselmo's existing neighborhoods and commercial areas.
LU 4. New developments in the Town's open hillside and ridge areas will be regulated to protect the natural beauty of these areas.
Objective
LU 1: To manage future growth to ensure the orderly development of the community, the logical extension of urban services, preservation of the area's natural and cultural resources, and protection of the area's environmental setting.
Policy
LU 1.2: Future growth will be managed based on the ability to provide needed public services, the constraints associated with development of the site, the costs and revenues associated with new development, and the effects of growth on local traffic conditions.
Objective LU 2: To preserve and enhance the unique natural and urban characteristics of the community while accommodating suitable new growth.
Policy
LU 2.1: All land use decisions within the Town and the planning area will take into consideration the protection and preservation of the area's surrounding hillsides, ridges, water courses, and any unique natural habitats.
LU 2.2: New development will be required to preserve some of the natural and cultural characteristics of their respective development sites.
Objective LU 3: To establish residential densities which are compatible with the environmental constraints of the area, and sensitive to adjacent land uses Policy
LU 3.1: Very low density (hillside and ridge) and single-family conservation residential development should be located in areas of (1) relatively high visibility, (2) environmental hazards, (3) sensitive environmental resources, or (4) areas which are established as high priority open space lands.
LU 3.2: Single-family residential development is most appropriate within and adjacent to existing single-family areas, and in areas easily served with water and sewer lines. Such areas should also serve as transition zones between mixed density and very low density areas.
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Table 20: Town of San Anselmo General Plan
Goal/Policy/
Program Explanation
LU 3.3: Mixed residential and housing opportunity development is most appropriate where sites have few environmental constraints, and have adequate facilities, such as water, sewer, transit, and access to commercial services.
Objective LU 7: To protect and preserve those areas of unique natural and visual resources within the planning area
Policy
LU 7.1: To limit or prohibit development in hazardous areas or areas of high resource value.
LU 7.6: 7.6 Continue to preserve open space and provide for the conservation of resources through innovative implementation including zoning, development controls (including grading, public and private acquisition, and incentives for private improvements which enhance the environment).
Objective
LU 9: To regulate future development on hillside and ridge parcels so as to protect, maintain, and enhance the natural characteristics of the land which contribute to the open space qualities of the parcel.
Policy
LU 9.5: New roads or extensions of existing roads which provide access to hillside and ridge parcels shall be limited in paved width to the minimum necessary to provide for adequate public safety
LU 9.7: Development on hillside and ridge parcels shall be so designed as to minimize grading and disruption of natural contours.
Objective
LU 13: To ensure that existing and future development in hillside and ridge areas has a continuous supply of domestic water, adequate water to protect structures from domestic and wild fires
Policy
LU 13.1: To encourage the Fire District to require sprinkler systems in new residential buildings which the Water District cannot supply with the ISO recommended fireflow.
LU 13.2: New homes shall hook into MMWD's system where feasible. If a water moratorium exists or public water cannot be provided, owners may construct potable water wells for new homes in accordance with the San Anselmo Municipal Code but shall connect to MMWD for their sole potable water supply as soon as water supplied by MMWD is available
Objective LU 14: To require homes and other improvements constructed in hillside and ridge or other high fire hazard areas to be designed to reduce the potential for a disastrous fire.
Policy
LU 14.1: To prohibit on street parking on public and private roadways which, due to their width or circuitous routing, create problems for fire equipment access.
LU 14.2: To prohibit the use of combustible roofing materials in residential areas that have a high wildfire potential (e.g., hillside and ridge areas).
LU 14.3: To require brush clearance around structures which encroach on wild vegetative groundcover.
Objective LU 15: To ensure that onsite sewage treatment systems do not create a potential health problem or contribute to a potential unstable slope condition.
Policy
LU 15.2: Where it is not feasible to hook into the Sanitation District collection system, the builder must supply a copy of a sanitation engineer's report to the Town stating that disposal is feasible on the site from a health standpoint. Further, a professional geotechnical report by a professional engineer shall be supplied to the Town stating that the proposed wastewater disposal field will not result in contribute to any landslide or other adverse geologic condition.
Objective LU 16: To protect the community from danger to life and property caused by flooding.
Policy LU 16.1: All new developments in the Town should be designed to minimize vegetation 1022
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Table 20: Town of San Anselmo General Plan
Goal/Policy/
Program Explanation
removal, soils compaction, and site coverage.
LU 16.2: To only allow development within the 100-year floodplain which is consistent with the Town's adopted Protection of Flood Hazard Areas and Water Course Ordinance.
LU 16.3: To inform the citizens of the community of existing and potential flooding problems on an ongoing basis.
LU 16.4: To repair and improve the Town's storm drainage system to handle existing and projected runoff.
LU 16.5: To prepare evacuation plans for flood-prone areas and distribute information to affected residents, businesses, and property owners
Objective
LU 17: To ensure that facilities needed to function in a natural disaster are not located in the floodplain or, if there is no other choice, that they are designed to function adequately under emergency conditions.
Policy
LU 17.1: Facilities designated as "critical" in the emergency preparedness plan should not be located in the 100-year floodplain, or if no other choice shall be designed to function adequately under emergency conditions.
Circulation Element
Goals
C 2. To design a roadway network which will maintain and enhance the quality of life on local residential streets in the community.
C 5. To support transportation improvements and emerging vehicle technology that help reduce greenhouse gas emissions.
Objective
C 10: To allow limited improvements to the existing narrow and circuitous roadways which provide access to ridge and hillside properties while maintaining their existing rural character.
Policy
C 10.1 The only improvements the Town will allow on existing roads which serve ridge and hillside properties are those necessary to improve safety and drainage. The types of improvements which will be allowed include: resurfacing of existing paved areas, cross slope correction, small automobile turnouts, isolated widening, straightening of roads to correct safety hazards, placement of mirrors at blind curves, improved roadway drainage, and repair of existing slides along the roadway, or improvements similar in nature to those described herein.
Objective C 17: To work toward more widespread use of electric vehicles to lower greenhouse gas emissions from transportation.
Policy
C 17.1: Zero Emission Vehicle readiness. Provide a foundation for electric vehicle implementation efforts, including investments in electric vehicle infrastructure and guidance for ongoing Town initiatives, by preparing an Electric Vehicle Strategy. The strategy should establish a framework for near-term actions that support longer-term mobility goals and initiatives, including, but not limited to, Town policy on costs and fees for Town charging stations, regulations for residential And workplace electric vehicle readiness, and policies for conversion of the Town vehicle fleet.
Open Space Element
Goal
OS 2. Protect ridgelines, including the ridge zone, and preservation of the natural features of hillside lands
Objective
OS 2: To prohibit development on the ridgeline and within the ridge zone of the major ridges identified on the Open Space and Conservation Map, as well as the secondary ridges
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Table 20: Town of San Anselmo General Plan
Goal/Policy/
Program Explanation
Policy
OS 2.8: Construction within the ridge zone shall be permitted only when the applicant has demonstrated to the satisfaction of the Town Engineer and Planning Commission that construction outside of the ridge zone would be detrimental with respect to soil and geologic conditions, vegetation removal, drainage, and such other factors as are determined to be pertinent.
Conservation Element
Goals
CO 1. Minimize environmental harm and the disruption of natural features, particularly in hillside and unstable soil areas.
CO 2. Protect creeks from pollution and against any unnecessary disturbance of the natural contours and vegetation of the banks.
CO 3. Establish policies and practical guidelines for the prevention of erosion, the stabilization of soils, and the protection of the watershed necessary to minimize excessive water runoff.
CO 5. Preserve ridgetops* and other locally important natural or man-made historic areas or features.
Policy CO 3: Activities causing damage to hydrological and biological processes shall be discouraged.
Policy
CO 4: Streams shall be maintained in or restored to their natural state. A flood channel maintaining the natural settings on San Anselmo Creek and Sleepy Hollow Creek shall be of adequate width and properly maintained to allow passage of flood waters and preservation of riparian vegetation and habitat. Removal of vegetation on the hillsides should be closely controlled in order to minimize erosion, siltation of watercourses, and runoff.
Policy CO 7: Construction shall be located and designed to avoid or minimize the hazards from earthquake, erosion, landslides, floods, fire, and accidents.
Policy
CO 9: Structures, parks, and other areas modified by man, where people spend most of their time, shall be healthful, safe, quiet, and of good design, both functionally and aesthetically.
Policy
CO 10: Projects shall not overburden the water supply, fire protection, waste disposal, schools, traffic and circulation, or other services and facilities, or adversely affect the financial or social environment of the community.
Policy
CO 11: Water supply, flood control, wastewater and solid waste disposal, soil conservation, and open space preservation shall be coordinated to create the greatest public benefit and the least degree of environmental damage.
Policy
CO 13: The Town and County shall take measures to reduce existing and future inefficient or unnecessary energy or natural resources consumption. Recyclable and biodegradable materials shall be utilized and used materials shall be recycled or reused whenever possible.
Town Parks, Recreation, and Public Facilities Element
Goal
PS C3: The natural appearance and runoff capacity of stream channels should be protected, preserved, and enhanced by the development of small improvements (e.g., small earth-fill dams for storm water retention) and landscaping rather than a major floodcontrol project such as the concrete channel in lower Corte Madera Creek. The channel lines on both sides of San Anselmo Creek should be protected from encroachment by development.
Table 268: Town of San Anselmo General Plan
Source: Town of San Anselmo General Plan
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3.2.2 ADMINISTRATIVE AND TECHNICAL CAPABILITIES
The administrative and technical capability identifies the Town personnel responsible for activities related to mitigation and loss prevention. Many positions are full time and/or filled by the same person.
Table 21: Town of San Anselmo Administrative and Technical Capabilities Administrative Yes/No Is coordination effective?
Administrative Services Y
Administrative Services Department handles finance and
purchasing, budgeting, risk management, information
technology, and business licensing for the community. The department may be responsible for implementing
mitigation actions related to the department’s scope.
Planning Commission Y
The Planning Commission meetings on the first and third Monday of each month. The Commission holds public
hearings and takes action on subdivisions, design reviews, conditional use permits, and items that may be forwarded to or called up by the commission.
Hazard Mitigation Planning
Committee N
Maintenance programs to
reduce risk (e.g., tree
trimming, clearing
drainage systems)
Y
The Town’s Public Works Department has sidewalk, tree,
and stormwater maintenance programs that reduce risk of injuries due to falls, fire, and floods.
Mutual aid agreements N
Technical Yes/No Has capability been used to assess/mitigate risk in the past?
Warning systems/services
(Reverse 911, outdoor
warning signals)
Y
Utilizes the County emergency warning systems through
the EAS system as their primary warning capability.
Utilizes the emergency warning systems through
telephone notification utilizing reverse 911.
Hazard data and
information Y
Data has been used for the determination of floodplain
areas. Different building code requirements are enforced based on the location of a structure in the floodplain to mitigate risk.
Grant writing Y
Grant writing is performed by Town staff and consultants.
Grants have been obtained for flood control, to improve sidewalk safety, replace failing bridges etc.
Hazus analysis N
Staff/Personnel Resources
Yes/No
Full
Time/
Part
Time
Is staffing adequate to enforce regulations?
Is staff trained on hazards and mitigation?
Is coordination between agencies and staff effective?
Chief Building Official Y/FT
The Building Official is a registered architect,
professional civil engineer, certified building official, and has a CAL OES certification. She is well trained on
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hazards and mitigation. She coordinates between the
Town, agencies, and staff.
Flood Control and Water
Conservation District Staff Y
The Marin County Flood Control and Water
Conservation District supports flood mitigation efforts by partnering with Cities and Towns to design, construct
and maintain flood control infrastructure and channel
improvements.
Emergency Manager Y/FT
The Public Works Director serves as the emergency
manager. He is adequate and well-trained to enforce
regulations. He coordinates between the Town,
agencies, and staff.
Community Planner Y/FT
The Planning Director serves as the community planner.
She is adequate and well-trained to enforce regulations.
She coordinates between the Town, agencies, and staff.
Civil Engineer Y/FT
The Town has multiple civil engineers under the Public
Works Department. All staff are involved with the
enforcement of regulations and are trained on hazard
mitigation.
GIS Coordinator N
Community Development
Staff Y/FT
Develops and maintains the General Plan, including the
Safety Element. Develops area plans based on the
General Plan, to provide more specific guidance for the development of more specific areas. Reviews private
development projects and proposed capital
improvements projects and other physical projects
involving property for consistency and conformity with
the General Plan.
Town Planning, Building,
and Public Works Staff Y/FT
These departments are responsible for planning and
building related activities including issuing permits,
conducting environmental review, preparing planning
documents, and addressing housing issues. Mitigation
activities related to planning and building can be
implemented by this department. Public Works
Department is responsible for Town-owned
infrastructure, including streets, bike lanes and
sidewalks, storm drains, traffic signals, and streetlights.
Mitigation actions involving new or retrofitted public
infrastructure, as well as those related to water
conservation, fall within the purview of the Public Works Department.
Police Department Staff Y/FT
The Ross Police Department conducts emergency
preparedness activities for the community. Mitigation
activities related to emergency preparedness can be
implemented by the Police Department.
Fire Department Staff Y/FT
The Ross Valley Fire Department protects the town
from the effects of fire and other hazardous conditions and supports implementation of mitigation actions that
reduce the risk of wildfire.
Volunteer Boards and Y The Town has several volunteer groups that can help 1026
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Commissions hazard mitigation efforts including the Town Council, Planning Commission, Flood Committee and the Quality
of Life Committee. These groups are both personnel
resources and can make recommendations to the Town
Council, the governing body, which can update
municipal and zoning codes.
Table 269: Town of San Anselmo Administrative and Technical Capabilities Source: Town of San Anselmo
3.2.3 FISCAL CAPABILITIES
The fiscal capability assessment shows specific financial and budgetary tools available to the jurisdictions such as community development block grants; capital improvements project funding; authority to levy taxes for specific purposes; fees for water, sewer, gas, or electric services; impact fees for homebuyers or developers for new development; ability to incur debt through general obligations bonds; and withholding spending in hazard-prone areas.
Table 22: Town of San Anselmo Fiscal Capabilities
Financial
Yes/No
Has the funding resource been used in past and for what type of activities?
Could the resource be used to fund future mitigation
actions?
Capital improvements project
funding Y
Funding has been included in the 5 Year CIP for flood
control projects, stormwater mitigation, fire hazard
reduction, etc both presently and in the past. The resource can and will be used in the future to fund mitigation
projects.
Authority to levy taxes for
specific purposes Y
San Anselmo along with the County of Marin gets funding from Measure C for Wildfire Mitigation. In addition,
Measure D (now J) a local sales tax has been used in the past for flood control mitigation. Both Measure C and J will be used in the future for wild fire mitigation and flood control, respectively. Measure J is also planned to be
used for stormwater cleanup and mitigation and climate
adaptation and resiliency. The measures could be used to fund future mitigation actions.
Fees for water, sewer, gas, or
electric services Y
Funding has not been used in the past for mitigation, but could possibly fund future mitigation activities. However, these utilities are not in the direct control of San Anselmo and may be limited by Public Utility Commission
regulations.
Impact fees for new
development Y Funding has not been used in the past for mitigation, but could possibly fund future mitigation activities.
Storm water utility fee
Incur debt through general
obligation bonds and/or
special tax bonds
Y
The Town has used general obligation bonds to fund
stormwater projects. Future funding could possibly be
obtained through these means.
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Incur debt through private
activities N The Town is a public entity and doesn’t incur private debt.
Community Development
Block Grant Y Funding has not been used in the past for mitigation, but could possibly fund future mitigation activities.
Other federal funding
programs
Y
Federal funding has been used in the past to mitigate
landslides and flooding. Federal funding could be used in the future to fund various projects including stormwater runoff, flood control, and climate adaption.
State funding programs Y
State funding has been obtained for replacement of
bridges which cause flooding along with funding for other flood control projects. Future state funding could be
obtained through the use of state funding for various
mitigation activities.
Table 270: Town of San Anselmo Fiscal Capabilities
Source: Town of San Anselmo
3.2.4 COMMUNITY OUTREACH
The outreach and partnerships capability assessment shows outreach and public education programs available to the Town of San Anselmo and the Town of San Anselmo partnerships utilized to promote those programs.
Table 23: Town of San Anselmo Community Outreach
Outreach and Partnerships Yes/No Could the program/organization help implement future mitigation activities?
Local citizen groups or
non-profit organizations
focused on environmental
protection, emergency
preparedness, access and
functional needs
populations, etc.
Y
The Town has several volunteer groups that can help
hazard mitigation efforts including the Town Council,
Planning Commission, Flood Committee and the Quality of Life Committee. These groups are both personnel
resources and can make recommendations to the Town
Council, the governing body, which can update municipal and zoning codes.
Local citizen groups or
non-profit organizations
focused on environmental
protection, emergency
preparedness, access and
functional needs
populations, etc.
Y
The Town Manager’s newsletter was initiated after the
2005-06 floods and became a regular method of
communication between the Town and its residents.
Ongoing public education
or information program
(e.g., responsible water
use, fire safety, household
preparedness,
environmental education)
Y
The Town partners with state and federal fire agencies.
Partnerships with these groups could assist in future
mitigation programs/actions.
Natural disaster or safety
related school programs Y The Town conducts Public Outreach Programs at local schools on Fire Safety. 1028
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StormReady certification N In the future the Town could look at participating in this.
Firewise Communities
certification Y Various neighborhoods in San Anselmo have Firewise Certification.
Community Rating System Y
A Countywide collaboration of CRS community staff has
been started in recent years and has led to shared
resources including outreach materials and floodplain
management training. This collaboration has the potential to expand and lead to a wide variety of flood mitigation activities.
Public-private partnership
initiatives addressing
disaster-related issues
Y
The Get Ready program, developed in the County of
Marin, is a free 2-hour course provided to the community.
The course is designed to help residents plan for an
emergency with a family plan, evacuation checklist, and strategies to keep residents and their families safe.
(https://readymarin.org/get-ready/)
Table 271: Town of San Anselmo Community Outreach
Source: Town of San Anselmo
3.2.5 PARTICIPATION IN THE NATIONAL FLOOD INSURANCE PROGRAM Town of San Anselmo has participated in the Regular Phase of the NFIP since December 1st, 2077. Since then, the Town of San Anselmo has administered floodplain management regulations that meet the minimum requirements of the NFIP. Under that arrangement, residents and businesses paid the same flood insurance premium rates as most other communities in the country.
The Community Rating System (CRS) was created in 1990. The Town of San Anselmo has been in the CRS program since May 1st, 2016. The program is designed to recognize floodplain management activities that are above and beyond the NFIP’s minimum requirements. CRS is designed to reward a community for implementing public information, mapping, regulatory, loss reduction and/or flood preparedness activities. On a scale of 10 to 1, the Town of San Anselmo is currently ranked Class 8 community, which gives a 10% premium discount to individuals in the Town of San Anselmo Special Flood Hazard Area (SFHA), and a 5%discount to policyholders outside the SFHA.
Presently, the Town of San Anselmo manages its floodplains in compliance with NFIP/CRS requirements and implements a floodplain management program designed to protect the people and property of the County. Floodplain regulations are a critical element in local floodplain management and are a primary component in the Town’s participation in the NFIP. As well, the Town’s floodplain management activities apply to existing and new development areas, implementing flood protection measures for structures and maintaining drainage systems to help reduce the potential of flooding within the Town.
The Town of San Anselmo will continue to manage their floodplains in continued compliance with the NFIP. An overview of the Town’s NFIP status and floodplain management program are discussed in Table 24. Additional information on the Town’s CRS program follows. 1029
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The activities credited by the CRS program provide direct benefits to the Marin County OA and its residents, including:
• Enhanced public safety;
• A reduction in damage to property and public infrastructure; • Avoidance of economic disruption and losses;
• Reduction of human suffering; and
• Protection of the environment.
The activities that the Town of San Anselmo implements and receives CRS credits include:
San Anselmo’s CRS program as of May 1, 2016.
Activity 310 – Elevation Certificates: Credit is provided for having written construction certificate management procedures for all new and substantially improved/substantially damaged buildings. (46 points)
Activity 320 – Map Information Service: Credit is provided for furnishing inquirers with basic flood zone information from the community’s latest Flood Insurance Rate Map (FIRM). Credit is also provided for the community offering additional FIRM information, historical flood information, and natural floodplain functions. The service is publicized annually and records are maintained. (90 points)
Activity 330 – Outreach Projects: Credit is provided for general outreach projects and targeted outreach projects. These projects are disseminated annually. (82 points) Activity 340 – Hazard Disclosure: Credit is provided for state regulations requiring disclosure of flood hazards. (15 points)
Activity 350 – Flood Protection Information: Documents relating to floodplain management are available in the reference section of the San Anselmo Library. Credit is also provided for floodplain information displayed on the community’s website. (73 points) Activity 360 – Flood Protection Assistance: Credit is provided for offering one-on- one advice regarding property protection and making site visits before providing advice. The service is publicized annually and records are maintained. (55 points) Activity 420 – Open Space Preservation: Credit is provided for preserving approximately 55 percent of the Special Flood Hazard Area (SFHA) as open space, and preserving open space land in a natural state. (46 points)
Activity 430 – Higher Regulatory Standards: Credit is provided for enforcing regulations that require freeboard for new construction and substantial improvement, foundation protection, cumulative substantial improvement, and local drainage protection. Credit is also provided for the enforcement of building codes and Building Code Effectiveness Grading Schedule (BCEGS®) Classification. (111 points)
Activity 440 – Flood Data Maintenance: Credit is provided for maintaining and using additional map data in the day to day management of the floodplain. Credit is also provided for 1030
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establishing and maintaining a system of benchmarks and maintaining copies of all previous FIRMs and Flood Insurance Study reports. (161 points)
Activity 450 – Stormwater Management: The community enforces regulations for soil and erosion control, and water quality. (52 points)
Activity 510 – Floodplain Management Planning: Credit is provided for the Marin County Operational Area Multi-Jurisdictional Local Hazard Mitigation Plan, adopted on September 17, 2019. A progress report must be submitted on an annual basis. (171 points) Activity 520 - Acquisition and Relocation : Credit is provided for a acquiring and/or relocating flood prone buildings so that they are out of the floodplain. (190 points) Activity 630 – Dams: Credit is provided for a State Dam Safety Program. (37 points) Repetitive Loss Properties
Repetitive loss records are as follows:
• Number of FEMA-identified Repetitive-Loss Properties: 4 • Number of FEMA-identified Severe-Repetitive-Loss Properties: 0 • Number of Repetitive-Loss Properties or Severe-Repetitive-Loss Properties that have been mitigated: All 4 RL properties were identified as “no” for mitigated. • There were 0 repetitive loss properties that were categorized as mitigated. • Repetitive Loss (RL) Residential Structures: 4
• Repetitive Loss (RL) Non-Residential Structures: 0
• Severe Repetitive Loss (SRL) Residential Structures: 0 • Severe Repetitive Loss (SRL) Non-Residential Structures: 0 Table 24: Town of San Anselmo NFIP Status
NFIP Topic Comments
Insurance Summary
How many NFIP policies are in the
community? What is the total premium and
coverage?
415 Policies
$495,946 Premiums
$125,204,000 coverage
How many claims have been paid in the
community? What is the total amount of
paid claims? How many of the claims were
for substantial damage?
285 Paid losses
$11,765,301 Paid losses
35 Substantial damage claims
How many structures are exposed to flood
risk within the community?
*“flood risk” is defined as the 1% annual
chance flood (100-year flood. Numbers are
from overlay of FEMA SFHA and building
stock data.
561 – GIS, Maps, Hand count
Describe any areas of flood risk with limited
NFIP policy coverage
Community FPA and FEMA Insurance Specialist
Staff Resources
Is the Community Floodplain Administrator
or NFIP Coordinator certified? Community FPA
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Is floodplain management an auxiliary
function? Community FPA
Provide an explanation of NFIP
administration services (e.g., permit review,
GIS, education or outreach, inspections,
engineering capability)
Community FPA
What are the barriers to running an effective
NFIP program in the community, if any? Community FPA
Compliance History
Is the community in good standing with the
NFIP?
Yes
Are there any outstanding compliance
issues (i.e., current violations)?
No
When was the most recent Community
Assistance Visit (CAV) or Community
Assistance Contact (CAC)?
June 28, 2019
Is a CAV or CAC scheduled or needed? No
Regulation
When did the community enter the NFIP? December 1st, 1977 Are the FIRMs digital or paper? Digital, some paper
Do floodplain development regulations meet
or exceed FEMA or State minimum
requirements? If so, in what ways?
Community FPA
Provide an explanation of the permitting
process.
Community FPA, State, FEMA NFIP
Community Rating System (CRS)
Does the community participate in CRS? Yes
What is the community’s CRS Class
Ranking?
Class 8
What categories and activities provide CRS
points and how can the class be
improved?
310 Elevation Certificates
320 Map Information Service – 90 Points
330 Outreach Projects – 82 Points
340 Hazard Disclosure – 15 Points
350 Flood Protection Information - 73 Points
360 Flood Protection Advice – 55 Points
420 Open Space Preservation - 46 Points
430 Higher Regulatory Standards – 111 Points
440 Flood Data Maintenance – 161 Points
450 Stormwater Management – 52 Points
510 Floodplain Management Plan – 171 Points
520 Acquisition and Relocation – 190 Points
630 Dams – 37 Points
Does the plan include CRS planning
requirements
Yes
Table 272: Town of San Anselmo NFIP Status
Source: FEMA, Town of San Anselmo
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3.3 MITIGATION GOALS
The information developed from the risk assessment was used as the primary basis for developing mitigation goals and objectives. Mitigation goals are defined as general guidelines explaining what each jurisdiction wants to achieve in terms of hazard and loss prevention.
Hazard Risk Prioritization
Mitigation Goals & Objectives
Mitigation Project Identification
Mitigation Project Implementation
Goal statements are typically long-range, policy-oriented statements representing jurisdictionwide visions. Objectives are statements that detail how each jurisdiction’s goals will be achieved, and typically define strategies or implementation steps to attain identified goals. Other important inputs to the development of jurisdiction-level goals and objectives include performing reviews of existing local plans, policy documents, and regulations for consistency and complementary goals, as well as soliciting input from the public.
The following represents overarching strategic goals associated with the identification and eventual implementation of appropriate and meaningful hazard mitigation efforts in relation to prioritized hazards and threats confronting the Marin County OA. These goals form the basis for specific supporting process objectives and are shown from the highest priority, at the top of the list, to those of lesser importance.
The establishment of hazard mitigation goals represents both individual and collective strategies that have been mutually agreed upon by the Steering Committee and have changed with the 2023 MJHMP update. Objectives were added to Goals 2 and 5. Eventually, these goals have been adopted by the Marin County OA, including each of its jurisdictions, as the guiding policy behind local hazard mitigation efforts, in conjunction with other associated principles.
Goals were defined for the purpose of this mitigation plan as broad-based public policy statements that:
• Represent basic desires of the community;
• Encompass all aspects of community, public and private; • Are nonspecific, in that they refer to the quality (not the quantity) of the outcome; • Are future-oriented, in that they are achievable in the future; and • A time-independent, in that they are not scheduled events.
Goals are stated without regard to implementation. Implementation cost, schedule, and means are not considered. Goals are defined before considering how to accomplish them so that they are not dependent on the means of achievement. Goal statements form the basis for objectives 44 CFR Requirement §201.6(c)(3)(i) [The hazard mi�ga�on strategy shall include a] descrip�on of mi�ga�on goals to reduce or avoid long‐term vulnerabili�es to the iden�fied hazards. 1033
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and actions that will be used as means to achieve the goals. Objectives define strategies to attain the goals and are more specific and measurable.
Goal 1: Minimize risk and vulnerability of the community to the impacts of natural hazards and protect lives and reduce damages and losses to property, economy, and environment in the Marin County OA.
• Minimize economic and resource impacts and promote long-term viability and sustainability of resources throughout the Marin County OA. • Minimize impact to both existing and future development. • Provide protection for public health.
• Prevent and reduce wildfire risk and related losses.
Goal 2: Provide protection for critical facilities, infrastructure, utilities, and services from hazard impacts.
• Incorporate defensible space and reduce hazard vulnerability. • Develop redundancies in utilities and services.
• Enhance resilience through enhanced construction.
Goal 3: Improve public awareness, education, and preparedness for hazards that threaten our communities.
• Enhance public outreach and participation in the Alert Marin Emergency Notification System.
• Enhance public outreach, education, and preparedness program to include all hazards of concern.
• Increase public knowledge about the risk and vulnerability to identified hazards and their recommended responses to disaster events, including evacuation and sheltering options.
• Provide planning and coordination for "At-Risk" populations. • Provide planning and coordination for companion animals, livestock, and other animal populations.
• Increase community awareness and participation in hazard mitigation projects and activities.
Goal 4: Increase communities' capabilities to be prepared for, respond to, and recover from a disaster event.
• Improve interagency (local, state, federal) emergency coordination, planning, training, and communication to ensure effective community preparedness, response and recovery.
• Enhance collaboration and coordination of disaster-related plans, exercises, and training with local, state, and federal agencies, neighboring communities, private partners, and volunteers.
• Enhance the use of shared resources/Develop a strong mutual aid support system. • Create and maintain a fully functional, interoperable radio and communication system with all regional public safety partners.
Goal 5: Maintain FEMA Eligibility/Position the communities for grant funding. • Review hazard events and ongoing hazard mitigation projects annually. • Assess the need to pursue or adjust hazard mitigation projects after significant hazard events.
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Goal 6: Reduce exposure to High Hazard Dams that pose an unacceptable risk to the public. • Improve alert and warning systems to provide residents downstream of a High Hazard Dam to receive timely warning to evacuation when threatened by potential or imminent dam failure.
• Enhance overall community preparedness to respond and evacuate a potential or imminent dam failure.
• Increase public awareness of the risk posed by High Hazard Dams and the potential for relocation of housing outside a possible inundation zone. • Prioritize High Hazard Dam Mitigation projects and programs.
3.4 STATUS OF PREVIOUS MITIGATION ACTIONS
Table 25 summarizes the actions that were recommended in the previous version of the hazard mitigation plan and their implementation status at the time this update was prepared.
Table 25: Status of Previous Hazard Mitigation Actions
Action Number / Name Completed Ongoing Not
Started
Still
Relevant
Included in
Updated
Action
Plan
Develop list of locally historic resources and create
incentives for private owners of historic or architecturally significant buildings to undertake mitigation to levels that will minimize the likelihood that these buildings will need to be demolished after a disaster and/or establish
preservation‐sensitive measures for the repair and re‐
occupancy of historically significant privately‐owned
structures.
X Yes
Develop unused or new pedestrian rights‐of‐way as
walkways to serve as additional evacuation routes. X Yes Encourage Marin Municipal Water District to review and
update mapped inundation area for Phoenix Dam and
coordinate with the Town on procedures for the
emergency evacuation of areas that would be inundated
by a failure of Phoenix Dam.
X Yes
Conduct an inventory of privately‐owned existing or
suspected soft‐story structures as a first step in
establishing voluntary or mandatory programs for
retrofitting these buildings.
X Yes
Use the soft‐story inventory to require private owners to inform all existing andprospective tenants that they live or work in this type of building and may need to be
prepared to live or work elsewhere following an
earthquake if the building has not been retrofitted.
X Yes
Require private owners to inform all existing tenants (and prospective tenants
prior to signing a lease agreement) that they live in an unreinforced masonry building and the standard to which it may have been retrofitted. Require private owners to inform all existing tenants that they may need to be
prepared to work elsewhere following an earthquake
even if the building has been retrofitted, because it has probably been retrofitted to a life‐safety standard, not to X Yes
1035
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TOWN OF SAN ANSELMO COMMUNITY PROFILE
Table 25: Status of Previous Hazard Mitigation Actions
Action Number / Name Completed Ongoing Not
Started
Still
Relevant
Included in
Updated
Action
Plan
a standard that will allow occupancy following major
earthquakes.
Continue Mapping of the creeks to further evaluate,
design, and implement additional flood control projects. X Yes Pursue funding for the design and construction of storm drainage projects to protect vulnerable properties,
including property acquisitions, upstream storage such
as detention and retention basins (excluding Memorial
Park), and channel widening with the associated right‐of‐ way acquisitions, relocations, and environmental
mitigations.
X Yes
Develop an approach and locations for various
watercourse bank protection strategies, including for
example, (1) an assessment of banks to inventory areas
that appear prone to failure, (2) bank stabilization,
including installation of rip rap, or whatever regulatory agencies allow (3) stream bed depth management using
dredging, and (4) removal of out‐of‐date coffer dams in rivers and tributary streams
X Yes
Working with stakeholders and the community, consider
feasibility (including cost, funding, environmental and downstream impacts) and options for removal of
Morningside Avenue Bridge and potential construction of upstream and downstream extended wing walls.
X Yes
Recognize that a multi‐agency approach is needed to
mitigate flooding by having flood control districts, cities, counties, and utilities meet at least annually to jointly discuss their capital improvement programs for most
effectively reducing the threat of flooding. Work toward making this process more formal to insure that flooding is considered at existing joint‐agency meetings.
X Yes
Improve upon existing hydrologic analysis of runoff and drainage systems to predict areas of insufficient capacity in the storm drain and natural creek system.
X Yes
Continue to develop guidelines that limit the coverage of impervious surfaces, that require the use of permeable
surfaces, that implement other regulations to effectively channel and minimize site runoff, and that allow water to percolate into the ground.
X Yes
Encourage home and apartment owners to get elevation
certificates. X Yes
Continue to encourage new development near floodways
to incorporate a
setback from watercourses to allow for changes in
stormwater flows in the watershed over time.
X Yes
Continue to have Town staff inspect creek areas after
each storm. X Yes
Work with other Ross Valley jurisdictions to explore and adopt land use regulations to minimize additional runoff, or reduce runoff, within the Ross Valley watershed.
X Yes
Working with stakeholders and the community, consider
feasibility (including cost, funding, environmental and downstream impacts) and options for flow bypass
accommodation for downtown constrictions
X Yes
As new flood‐control projects are completed, request that X Yes 1036
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Table 273: Status of Previous Hazard Mitigation Actions Source: Town of San Anselmo
Table 25: Status of Previous Hazard Mitigation Actions
Action Number / Name Completed Ongoing Not
Started
Still
Relevant
Included in
Updated
Action
Plan
FEMA revise its flood‐ insurance rate maps and digital
Geographic Information System (GIS) data to
reflect flood risks as accurately as possible.
Consider adopting cumulative substantial improvement
requirement of 3 to 5 years under Municipal Code
Protection of Flood Hazard Areas.
X No
Update hydraulic model at least once every ten years, or more frequently if there is a major development in the
watershed or a major change in the Land Use Element
of the General Plan of the cities or counties within the watershed.
X Yes
Require an annual inspection of approved flood‐proofed
privately‐owned buildings to ensure that (a) all flood‐ proofing components will operate properly under flood
conditions and (b) all responsible personnel are aware of their duties and responsibilities as described in their building’s Flood Emergency
Operation Plan and Inspection & Maintenance Plan.