Cloverdale Fire Protection District CWPP

This Community Wildfire Protection Plan (CWPP) provides a science-based assessment of wildfire hazard and threat to properties and homes in the wildland urban interface and intermix (WUI) within the Cloverdale Fire Protection District (CFPD) in Northern Sonoma County, California. The purpose of the CWPP is to provide fire agencies, land managers, and community members with strategies and an action plan to protect people, homes, and properties in the community.

This CWPP represents analysis and ground survey work conducted in 2021 and is intended to supplement the Sonoma County CWPP. The CWPP was developed through a collaborative process involving CFPD, CAL FIRE, local officials, FireSafe Sonoma, land management agencies, and community members. It meets the requirements set forth in the federal Healthy Forests Restoration Act (HFRA) for the development of CWPPs, which include:

• Ensuring Stakeholder collaboration

• Addressing structural ignitability

• Identifying and prioritizing areas for fuel reduction activities

A mitigation plan is part of this CWPP and contains a list of priority areas and projects for future mitigation work. The goal of the mitigation plan is to provide the CFPD and community members with a specific list of actions to help reduce the risk of catastrophic wildfire within the WUI, while ensuring the protection and enhancement of economic and ecological values and resources within the CFPD’s jurisdiction. Special focus was given to the road network and issues related to access and egress in the event of an evacuation. The intent is consistent with the mission of the CFPD and builds upon the CFPD’s ongoing wildfire mitigation activities, the Sonoma County CWPP, and other CFPD plans and policies. This CWPP and mitigation plan is focused on current conditions and recommends sound, long-term strategies for:

• Vegetation management and improvements to existing roadways and fuel breaks;     
• Improvements to public outreach and education activities to address structural ignitability and defensible space; and   
• Support for developing Firewise USA® accredited communities throughout the CFPD to help homeowners learn how to adapt to living with wildfire while encouraging and empowering neighbors to work together to reduce their wildfire risk and prevent losses.

Using geographic information system (GIS) analyses combined with ground and aerial surveys, an online Community Basemap was developed that contains multiple map layers of information that were used to inform this CWPP ( Community Basemap can be accessed here ). This CWPP is aligned with the California Strategic Fire Plan, the Sonoma County CWPP, and the Cloverdale Local Hazard Mitigation Plan (LHMP), which was completed in November 2021.

The CFPD is located along Highway 101 in Northern Sonoma County and is approximately 68 square miles (43,335 acres) with a population of approximately 11,500. The CFPD is bordered by Mendocino County to the north, Geyserville to the south, and rural areas to the east and west. Much of the CFPD is rural, undeveloped, and forested, and not served by fire hydrants. The city of Cloverdale is in the center of the CFPD with most of the urban landscape concentrated in the area along Highway 101.

Approximately 5% of the CFPD’s land area falls within the Wildland Urban Interface (WUI). However, a much larger portion, 55%, falls into the wildfire influence zone that contains vegetation susceptible to wildfire and narrow roadways that pass through neighborhoods into densely vegetated areas. Because of the mix and density of structures and natural fuels, combined with limited access and egress routes, fire management is more complex in WUI environments. In addition, rapid response times to areas far from the city can be challenging because the CFPD covers such a large area. Therefore, it is critical that roadways provide direct access and egress during emergency situations. The interactive map below shows the different wildland zones within the Cloverdale Fire District Boundary area.

Fire protection in California is the responsibility of either the federal, state, or local government. On federally owned land, or federal responsibility areas (FRA), fire protection is the responsibility of the federal government, often in partnership with local grants and contracts. In state responsibility areas (SRA), which are defined according to land ownership, population density, and land use, CAL FIRE has a legal responsibility to provide fire protection. Public Resources Code, Section 4126 designates SRAs as a state- or privately owned forest, rangeland, or watershed. CAL FIRE is not responsible for densely populated areas, incorporated cities, agricultural lands, or federal lands. Local responsibility areas (LRA) include incorporated cities and cultivated agriculture lands. In LRAs, fire protection is provided by city fire departments, fire protection districts, or counties, or by CAL FIRE under contract to local government. SRA designations undergo a five year review cycle, as well as annual updates to reflect incorporations/annexations, fixes, and ownership changes (which do not require Board of Forestry approval).

The weather, vegetation and fuel characteristics, topography, and land-use history are important factors for the fire environment within the CFPD. Strong, northeasterly, offshore winds create the wind regime that is commonly associated with the largest and most destructive wildfires in Northern California. These “North” winds occur as high-pressure forms in the Great Basin and drive air over the Sierra Nevada Mountains (from the east) and down toward the Pacific Ocean (to the west and south). When the winds travel over the Sierra Nevada Mountains, the descending air is compressed which lowers the relative humidity resulting in strong dry winds. When these winds travel through canyons, they create strong gusts.

The city of Cloverdale and the CFPD area includes the cold-winter valley floors, canyons, and land troughs characteristic of the California coastal ranges. Fall afternoon winds are common, with strong drying winds observed from summer to late fall. Lowland valley areas, and surrounding ridges and hilltops experience colder winters. The Mediterranean climate experiences summer drought, with typical rainfall measured between May and October at less than 0.5 inches, and has lower relative humidity (RH) and lower overnight RH recovery than nearby coastal valleys. These conditions may contribute to slight to moderate increases in expected fire behavior relative to surrounding areas.

Research on climate change and wildfires in the western United States, including California, indicates that climate change has increased the annual area burned by fire, as well as the likelihood of high- severity fires. This is due in part to an increase in the frequency of days with extreme fire weather, increased aridity, and a lengthening of the fire season. Climate projections indicate that the annual area burned and the threat of high-severity fire will likely increase in the future as the western United States warms and becomes more arid.

In the context of wildland fire, vegetation is also referred to as fuel, and plays a major role in fire behavior and potential fire hazard. A fuel’s composition (including moisture level, chemical makeup, and density) determines its degree of flammability. Of these, fuel moisture 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 determine how quickly a fire can spread and how intense or hot it may become. High moisture content slows 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 Sonoma County) 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 fire to spread readily. However, if fuels are so close that air cannot circulate easily, the fuel will not burn freely.

The CFPD has extensive topographic diversity that supports a variety of vegetation types (see the interactive map below). Environmental factors, such as temperature, precipitation, soil type, aspect, slope, and land use history, all help determine the existing vegetation at any given location.

As part of the Sonoma County Vegetation Mapping and LiDAR Program ( Sonoma Veg Map ), a fine scale vegetation and habitat map using the National Vegetation Classification Standard was developed (shown in the map above). The high-resolution vegetation and habitat map were inputs for the development of a 5-meter spatial resolution fuel model. The fuel model, created by the Pepperwood Foundation, represents surface vegetation and structure according to Scott and Burgan’s fuel model classification scheme. Fuel model data are used as input to fire behavior models and provide a simplified means for estimating fire behavior given the mix of vegetation in a specific area. Vegetation distribution across the CFPD is characterized by 44 distinct classes, but only 10 classes represent approximately 90% of the total land area of the CFPD. The table below lists the top 10 fuel model types present in the CFPD.

Many of the native tree species that occur in the coastal forests are well-adapted to drought and are able to survive and persist through hot and dry seasons. However, the persistent and severe drought conditions are worsening already widespread forest health issues and resulting in new insect and disease outbreaks. Sudden oak death has had a significant impact on the county due to the large number of oak trees. Sudden oak death has resulted in stands of essentially dead trees with very low fuel moistures, the tanoak in particular. In addition to tanoak mortality, there are an increasing number of dead and dying Douglas Fir trees in the hills west of Cloverdale and along the west side of Highway 101 north of Geyserville. Studies indicate that over longer time scales (over 8 years), rates of spread, fireline intensity, and flame lengths could drastically increase in diseased tanoak forests due to an increase in fuel loading.

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. 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% to 40%, flame heights can double and rates of fire spread can increase fourfold; from 40% to 60%, flame heights can become three times higher, and rates of spread can increase eightfold.

Fire history is an important part of predicting potential future fire frequency, fire behavior, and ignition sources. Based on data available from CAL FIRE, the historical fire record shows that there have been twelve large wildfires (greater than 500 acres) within the CFPD since 1878. There have been smaller wildfires that have occurred throughout the CFPD that are not reflected in this data. Boundaries of historical fires (pre-1970) may not be completely accurate, as modern technology and data collection methods allow for more precise mapping of wildfire boundaries. More recent fires tend to burn on the eastern side of the CFPD, thereby making the eastern side potentially more vulnerable. This knowledge helps us understand the frequency and location of future fires.

To take effective action, the CFPD and property owners must understand the elements and factors that contribute to the problem. This hazard assessment, in conjunction with the CFPD’s desire to implement recommended mitigation strategies, presents a unique opportunity to treat risk at the community level. Information in this report is based on several available data sources, including the  Sonoma County   CWPP,  the  Sonoma County GIS  database augmented by information collected during the CWPP process, the  Sonoma County-level wildfire hazard assessment,  public meetings held in 2021, site visits conducted in 2021, meetings with CFPD staff, published reports, and the professional knowledge of the consultants.

The first map illustrates modeled flame length for an extreme fire season scenario; dark red and red areas show potential flame lengths greater than 8 feet, indicating areas that might exhibit more extreme fire behavior and/or be relatively more hazardous from a fire suppression perspective.

The second map illustrates modeled rate of spread. 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. The dark red areas show where more extreme fire behavior is likely given an ignition.

The large interactive map below illstrates the Sonoma County Wildfire Hazard Index. The Sonoma County Wildfire Hazard Index is a model that predicts relative wildfire hazard on the landscape. Higher index values represent a higher relative hazard. The index is based on inputs that inform potential fire behavior, inputs that represent fire probability occurrence in any 1 pixel, and a model of wildfire suppression difficulty. A full desciption and reference information can be found here:  Sonoma County Wildfire Hazard Index Site .

Assets at risk are defined as structures and resources that can be damaged or destroyed by wildfire. Assets in Cloverdale include real estate (homes and businesses), schools, water distribution, historical sites, utilities and electrical distribution infrastructure, communications networks and facilities, transportation infrastructure, watersheds, protected open-space, recreation areas, and agricultural lands.

The objective of developing mitigation strategies is to establish a multifaceted approach to minimize the risk of catastrophic wildfire within the WUI while ensuring the protection and enhancement of economic and ecological values and resources within CFPD’s jurisdiction. To this end, a three-pronged mitigation approach was developed focused on 1) improving access and egress on key roadways; 2) maintaining fire roads and fuel breaks, 3) promoting preparedness and fire resilient neighborhoods through improved outreach, education, and Firewise USA ® neighborhood accreditation. And when feasible, improving forest health through stewardship to create sustainable forest structure that is more resilient to disturbances, such as wildfire and climate change, which helps to protect the community.

Improving Access and Egress on Key Roadways/Maintaining Fire Roads and Fuel Breaks

• Based on the identified areas of concern, a mitigation strategy and corresponding Vegetation Management Plan (VMP) was developed. Through collecting GIS data, walking historical routes, ground-truthing, and analysis, a network of 43 roadways were identified (shown in the internactive map below). These routes form the framework for the VMP, which will be carried out in multiple phases as funding becomes available. The first phase includes an environmental review for the pilot project and implementation of the pilot project. Beyond the pilot project, additional projects will be prioritized and implemented by with the CFPD. It is critical that ongoing maintenance remains a priority relative to this mitigation plan.

Promoting Preparedness and Fire Resilient Neighborhoods

• Mitigation strategies for achieving community-wide protection require acceptance throughout the community. The community must have the desire and ability to manage wildfire risk and maintain a dialogue with local fire officials. Cloverdale has several active volunteer groups that will continue to work to prepare the community for wildfire and organize training on home hardening and defensible space, including Asti-Cloverdale COPE and Northern Sonoma County CERT.

Public Outreach and Education

•  FireSafe Sonoma  is a county-wide organization that supports fire agencies and communities throughout Sonoma County and hosts several public outreach and community workshops each year to educate Sonoma County residents about wildfire preparedness. In addition to personal preparedness, animal owners should plan for evacuating pets and large animals. Several local government resources exist to assist animal owners in developing an evacuation plan including (but not limited to) the  HALTER Project ,  Sonoma Humane Society , and  Sonoma County Animal Services .

Home Hardening

• Fire-resistant building materials and designs are extremely effective at reducing structural ignitions. These include a wide variety of materials combined with engineering and design choices for nearly every aspect of home construction, ranging from relatively expensive materials such as tempered glass and upgraded roofing, to simple, inexpensive but effective features such as fine wire mesh covering attic and basement vents. Many of these features can be retrofitted or applied to new construction. When homeowners take action to harden their homes and lessen the ignitability of the home ignition zone, they dramatically increase their home’s survivability.

Defensible Space

• Landscaping is particularly critical in areas of potential wildfires because vegetation close to structures can become fuel for a fire. Clearing, grading, and siting all impact soil stability and erosion, and can be included as part of the design or building permit review process. Individual homeowners are ultimately responsible for the protection of their homes from wildfire. In a severe wildfire event, the fire service cannot protect all homes at risk. Individual responsibility and preparation undertaken long before a wildfire starts is of paramount importance.

Recommend Enhanced Defensible Space for Properties Adjacent to Open Space or Natural Vegetation

• Properties at the boundary of large parcels of open space (private or public) should be encouraged to maintain enhanced defensible space to the extent that is possible and practical. Where property lines are adjacent, property owners are encouraged to work collaboratively to support vegetation management. Specific recommendations include cutting grass, thinning tree canopies, enhanced spacing of landscaping plants, and thinning vegetation from structures on the side(s) facing contiguous vegetation.

Firewise USA® Accreditation

• Firewise USA®, a program designed to give local communities tools and incentives to reduce their wildfire hazard at the neighborhood and community levels, builds on the power of neighbors and other trusted sources to motivate hazard reduction.

This CWPP provides a framework and a starting point for ongoing wildfire mitigation efforts and continued community engagement throughout the CFPD. The CFPD received a grant from the county of Sonoma Agriculture and Open Space to jump start the vegetation management work outlined in Appendix C. Grant funds will be used to reduce hazards in priority areas identified in the community. Funding will be allocated to expand and enhance defensible space and improve fire breaks and egress for homeowners. The strategies outlined in this CWPP action plan will be the priority for vegetation management grant funds and private property funding to best reduce hazard areas.

The following recommendations will be sustained by the on-going efforts of the Cloverdale community and future revisions of this plan. The following is a list of prioritized recommendations and an outline of the action plan:

1. Mitigation & Maintenance of identified areas: (Appendix C of the CWPP document):
   1. Environmental Review for the priority (pilot) roads identified in the mitigation plan
   2. Pilot Road Project (6 roads)
   3. Environmental review for remaining project areas
   4. Mitigation plan for remaining project areas
   5. Ongoing maintenance work via hand, mechanical, prescribed fire, grazing, and approved herbicides
2. Firewise USA ® Accreditation
3. Continued community engagement in fire planning, prevention, and mitigation
   1. Encourage citizens to participate in preparedness clinics - DIY home hardening and DIY defensible space
   2. Encourage property owners to abate vegetation hazards
   3. Bilingual engagement and education
   4. Enhanced early warning systems (video+), GIS mapping, and communications
   5. Collaborative efforts with the City of Cloverdale
   6. Coordination of wildfire related projects between community groups such as COPE, CERT, etc.