Calistoga City Council
October 6, 2026

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Problem No. Hazard Area of
Concern
Primary
Agency
Problem Description Related MA
ps-WF-CN-12 Wildfire Impact City of Napa Longer, more intense wildfire seasons and smoke events are expected to continue
affecting Napa, increasing the likelihood of
repeated smoke impacts, PSPS events, and
regional wildfires that disrupt outdoor
commerce and tourism.
ma-WF-CN-45,
ma-WF-CN-45,
ma-WF-CN-41,
ma-WF-CN-50,
ma-WF-CN-44,
ma-WF-CN-42,
ma-AH-CN-9, maWF-CN-61, maAH-CN-3, ma-CCCN-51, ma-AHCN-7, ma-WF-CN43 ps-WF-CN-14 Wildfire Impact City of Napa WUI areas and open space, including Westwood Hills Park, Timberhill Park and
adjacent hillsides, contain heavy fuel loads
and access constraints that could lead to fastmoving fires, impediments to deploying firefighting resources, and threats to nearby
homes and evacuation routes.
ma-WF-CN-50,
ma-AH-CN-8, maWF-CN-41, maWF-CN-43

3.6 Mitigation Strategy
This section provides the framework for how the City of Napa will reduce hazard risk within its jurisdiction while supporting the broader goals of the Napa County MJHMP. It includes an overview of existing capabilities, opportunities to strengthen resilience, and the city’s prioritized mitigation actions. Together, these elements demonstrate how Napa integrates hazard awareness into its planning and development processes while contributing to a coordinated countywide approach.

Within the Napa County MJHMP, the mitigation strategy serves as the roadmap for future hazard mitigation efforts. For Napa, the strategy outlined in this annex reflects the outcomes of the countywide planning process while also addressing the city’s unique risks, priorities, and community needs. The strategy is designed to reduce vulnerabilities identified in the risk assessment, including the problem statements developed for flooding, earthquakes and liquefaction, slope failure, wildfire, drought, severe storms, extreme heat, and climate change.

Mitigation actions identified in this annex include both policy-based and project-based initiatives, with an emphasis on integrating resilience into land use planning, infrastructure investments, and community programs. Actions are structured to align with FEMA’s requirements and to coordinate with existing city, county, and regional planning mechanisms. Each action identifies responsible parties, potential funding sources, and the resources needed for implementation.

For Napa, this strategy provides a framework for strengthening resilience by combining city-led initiatives, such as infrastructure improvements, building code enforcement, and community preparedness, with regional coordination through the MJHMP. By advancing these efforts in alignment with the General Plan CAL OES SUBMITTAL - JUNE 2026
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and other local planning documents, the City of Napa staff can reduce hazard risk while supporting longterm community safety, sustainability, and economic stability. The subsections that follow describe these elements in detail:
▪ Sections 3.6.1, Capabilities and Opportunities, provides a summary of the city’s capacity to address natural hazards.
▪ Section 3.6.2, Mitigation Action Plan, presents Napa’s prioritized actions to guide implementation in coordination with countywide strategies.
▪ Section 3.6.3, Status of Previous Mitigation Actions, provides a summary of all previous actions and their current status, whether completed, cancelled, or revised.

Aligning the Action Plan
This section connects Napa’s mitigation actions with its existing capabilities and areas for growth.

Capability assessments are a required element of hazard mitigation planning under the Disaster Mitigation Act of 2000 and FEMA’s 2023 guidance, ensuring that actions are realistic, achievable, and aligned with available resources.

The section begins with a summary of Napa’s capabilities across four areas: planning and regulatory, administrative and technical, fiscal, and education and outreach. This overview highlights the tools and strengths that the district already uses to reduce hazard risk. The section then provides a detailed analysis of each capability area, identifying both current practices and opportunities to expand resilience.

Capabilities & Opportunities
This section provides a detailed assessment of the city’s current capabilities to support hazard mitigation, as well as future opportunities. This consists of describing how the city is planning for hazards and growth and a summary of its existing capabilities and the potential for enhancement.

3.6.1.1 Planning for Hazards & Growth
The City of Napa has adopted a comprehensive approach to balancing growth with hazard mitigation, recognizing that its location within the Napa Valley presents both development opportunities and exposure to natural hazards. Since its incorporation, the City has emphasized thoughtful land use planning to support economic vitality, maintain community character, and reduce vulnerability to hazards such as flooding, wildfire, and seismic activity.

Long-Range Planning & Growth Management
The City’s General Plan provides the framework for future growth and development, emphasizing infill development, redevelopment, and efficient land use within existing urban boundaries rather than outward expansion. Much of Napa is already developed, and future growth is expected to occur through CAL OES SUBMITTAL - JUNE 2026
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redevelopment of underutilized sites, adaptive reuse, and targeted infill in established areas, including downtown Napa, commercial corridors, and transit-accessible locations.

The Housing Element identifies capacity for additional residential development to meet state housing requirements, with an emphasis on higher-density and mixed-use projects that support walkability and reduce reliance on expansion into undeveloped or hazard-prone areas. This approach allows the City to accommodate growth while minimizing exposure to wildfire risk in surrounding hillsides and open space areas.

Downtown Napa and surrounding mixed-use areas continue to serve as focal points for revitalization and economic development. Ongoing and planned projects integrate housing, commercial uses, and public spaces while incorporating modern infrastructure improvements and resilience considerations. These efforts support both community development and hazard mitigation objectives by directing growth toward areas with existing services and infrastructure capacity.

As part of its planning framework, the City integrates hazard information from the Hazard Mitigation Plan into land use decisions, capital improvement planning, and development review processes. Updated mapping, risk assessment tools, and climate considerations are used from this plan to inform where and how development occurs, helping to reduce long-term risk and improve resilience.

By focusing on infill development, infrastructure investment, and risk-informed planning, the City of Napa continues to guide growth in a manner that is sustainable, resilient, and responsive to evolving environmental and hazard conditions.

Building Codes & Development Standards
The City of Napa emphasizes resilient growth management through the integration of state building codes, local ordinances, and hazard-informed development standards. As with other California jurisdictions, Napa enforces some of the most rigorous building regulations in the country, ensuring that new development and redevelopment meet high standards for structural safety, sustainability, and hazard resilience.

The City is required to regularly update its development regulations to remain consistent with the California Building Code (CBC), which is revised on a three-year cycle and most recently updated in 2025. The CBC establishes minimum standards for structural integrity, seismic performance, fire resistance, and accessibility. In addition, Napa enforces the California Fire Code, California Residential Code, and California Green Building Standards Code (CALGreen), which incorporate requirements related to energy efficiency, sustainable construction, and climate adaptation. Together, these codes provide the foundation for reducing long-term risk through the built environment.

The City of Napa Municipal Code includes several chapters and provisions that directly address natural hazards and risk reduction, providing a regulatory framework that supports hazard mitigation and resilience. These hazard-related regulations are distributed across multiple titles and address a range of hazards including flooding, seismic risk, wildfire, drought, and water supply reliability.

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Water supply, drought, and water conservation are addressed under Title 13 – Public Services, which includes Chapter 13.04 (Water Service System), Chapter 13.09 (Water Conservation Regulations), and Chapter

13.10 (Water Shortage Regulations). These chapters establish policies and operational procedures to manage water demand, respond to drought conditions, and ensure long-term water supply reliability.

Flood hazards are addressed through multiple regulatory mechanisms. Within Title 17 – Zoning, Chapter

17.38 (Floodplain Management Overlay District) establishes requirements for development within floodprone areas, including permitting, development standards, and floodplain administrator responsibilities.

Additional flood-related provisions are included in Title 15 – Buildings and Construction, which incorporates state building standards and drainage requirements, and in Title 8 – Health and Safety, Chapter

8.36 (Storm Water Quality Control), which regulates stormwater runoff and water quality.

Seismic hazards are addressed through Title 15 – Buildings and Construction, including provisions adopting the California Building Code and related standards for seismic design and structural safety. In particular, Chapter 15.110 (Review, Rehabilitation and Abatement of Existing Seismically Unsafe Buildings) establishes requirements for identifying and mitigating risks associated with vulnerable structures.

Wildfire risk is addressed through adoption of the California Fire Code and the California Wildland-Urban Interface (WUI) Code within Title 15, which establish construction standards, defensible space requirements, and fire-resistant design measures for development in fire-prone areas.

Additional hazard-related provisions are incorporated through zoning overlays and site development standards within Title 17, including hillside development controls (Chapter 17.40 – Hillside Overlay District), watercourse setbacks (Chapter 17.50 – Water Setback Overlay District), and other land use regulations that limit development in hazardous areas.

Finally, emergency management and disaster preparedness are addressed in Title 2 – Personnel and Administration, including Chapter 2.88 (Continuity in Government) and Chapter 2.89 (Emergency and Disaster Preparedness), which establish the City’s framework for emergency response, coordination, and continuity of operations.

Together, these chapters demonstrate that the City of Napa has dedicated and integrated regulatory mechanisms addressing major natural hazards, including flooding, seismic risk, wildfire, and drought, as well as broader emergency management and infrastructure resilience considerations.

In addition to these regulatory measures, the City of Napa participates in the National Flood Insurance Program (NFIP), which requires development within mapped flood hazard areas to meet or exceed established flood protection standards. This participation supports continued eligibility for flood insurance and reinforces community-wide flood risk reduction.

Through the consistent application of these codes, policies, and regulatory tools, the City of Napa ensures that new development is either directed away from hazard-prone areas or designed to withstand identified risks, supporting long-term resilience and sustainable growth.

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California Environmental Quality Act (CEQA)
The California Environmental Quality Act (CEQA) requires General Plans, Specific Plans, and major development projects to evaluate hazards such as flooding, wildfire, seismic risk, and slope instability.

Environmental documents must identify these risks and propose mitigation measures to reduce impacts, which may include infrastructure upgrades, evacuation planning, geotechnical design standards, or limits on development in high-risk areas.

CEQA plays an important role in Napa’s planning and development framework, ensuring that growth decisions incorporate environmental and hazard considerations. City of Napa serves as the lead agency for local projects, meaning the city must prepare and certify environmental review documents before approving discretionary development. These include Initial Studies, Mitigated Negative Declarations (MNDs), and Environmental Impact Reports (EIRs) depending on the project’s scope and potential impacts.

City of Napa recently integrated CEQA compliance into its 2022 General Plan update, which included an Environmental Impact Report (EIR) prepared pursuant to CEQA Guidelines. The General Plan EIR evaluates the impacts allowed by development policies in topic areas such as geology and soils (earthquakes, slope failure), hydrology and water quality (flooding and stormwater), biological resources, wildfire hazards, greenhouse gas emissions, and climate change. By addressing these issues at the General Plan level, Napa is able to use a tiered CEQA review process for future projects, streamlining environmental review for developments that are consistent with General Plan policies while still requiring project-specific mitigation for issues not fully analyzed in the program EIR.

Through CEQA, Napa must identify significant impacts, consider alternatives, and adopt mitigation measures, such as slope stabilization, defensible space, stormwater controls, or floodproofing. The City’s Safety Element and Municipal Code ensure these mitigation measures become enforceable project conditions. This process also enhances transparency, as CEQA requires public participation—residents, businesses, and stakeholders can review draft environmental documents and comment on hazard and environmental concerns before final approvals.

3.6.1.2 Development & Hazard Considerations
The City of Napa encompasses approximately 18 square miles and serves as the economic and governmental center of Napa County, with a mix of urban, suburban, and industrial land uses. Unlike smaller, more constrained jurisdictions, Napa includes both developed urban areas and remaining opportunities for infill and redevelopment. While much of the city is built out, future growth is expected to occur primarily through infill development, redevelopment of underutilized parcels, and targeted development within mixed-use and commercial corridors, including downtown Napa and areas along major transportation routes. Additional incremental development may occur through adaptive reuse of existing commercial and industrial sites and limited expansion within designated planning areas.

Napa’s regulatory framework requires that new development conform to California’s strict planning and building codes, as well as local floodplain management, seismic safety, and fire protection standards. These CAL OES SUBMITTAL - JUNE 2026
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measures reduce, but do not eliminate, exposure to natural hazards. As the City continues to accommodate housing and economic development, hazard considerations remain central, particularly given the presence of the Napa River, surrounding hillsides, and proximity to wildfire-prone areas.

Flood Hazards: Flood risk in the City of Napa is primarily associated with the Napa River and its tributaries, including Napa Creek, Tulucay Creek, and other drainage systems that traverse the city. FEMA Flood Insurance Rate Maps (FIRMs) identify portions of the city within the 1% and 0.2% annual chance floodplains, particularly in low-lying areas near the river corridor, downtown Napa, and southern portions of the city.

While major flood control improvements have reduced risk in many areas, a significant number of residents, structures, and critical infrastructure remain exposed. Future development and redevelopment in these areas require compliance with floodplain management regulations, including elevation standards, floodresistant construction, and stormwater management measures to reduce localized flooding.

Wildfire Hazards: While much of the City of Napa is urbanized, it is bordered by wildland and open space areas that are susceptible to wildfire. Hillside areas and the urban–wildland interface along the eastern and western edges of the city face the greatest risk. New and redeveloped structures in these areas must comply with California Fire Code and Wildland-Urban Interface (WUI) standards, including defensible space requirements, ignition-resistant construction, and fire-safe landscaping. Wildfires in surrounding areas may also affect the city through evacuation needs, degraded air quality, and strain on emergency response resources.

Seismic and Liquefaction Hazards: The City of Napa is located in a seismically active region and is subject to strong ground shaking from nearby faults, including the West Napa Fault Zone. In addition, portions of the city, particularly along the Napa River corridor and valley floor, are underlain by alluvial soils with moderate to high liquefaction susceptibility. A major earthquake could result in structural damage, ground settlement, pipeline rupture, and disruption to transportation and utility systems. Future development in these areas must incorporate seismic design standards, geotechnical investigations, and appropriate foundation and infrastructure design to reduce the risk of earthquake-related damage.

Drought: The City of Napa relies on a combination of local and regional water sources, including surface water and groundwater supplies. Extended drought conditions, which are expected to become more frequent and severe with climate change, can reduce water availability and increase demand. Growth and development will place additional pressure on water resources, requiring continued emphasis on water conservation, efficient infrastructure, and long-term supply planning. Local policies and programs support reduced water use, drought-tolerant landscaping, and system reliability to address these challenges.

If development occurs within hazard-prone areas, municipal codes require implementation of measures to reduce risk and minimize potential losses. To support community safety, emergency response and evacuation planning must consider local demographics, including vulnerable populations, as well as potential impacts such as service disruptions and limited access during hazard events. Overall, the City’s approach to managed growth, combined with regulatory requirements and hazard mitigation planning, is CAL OES SUBMITTAL - JUNE 2026
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intended to ensure that future development does not significantly increase vulnerability to identified hazards.

3.6.1.3 Capabilities & Opportunities Assessment
To develop a realistic and actionable mitigation strategy, it must account for existing jurisdictional capabilities and what future opportunities there are to enhance those capabilities for purposes of hazard mitigation. This section provides an assessment of the City of Napa’s existing capabilities and future opportunities, including planning and regulatory, administrative and technical, fiscal, and public outreach and education capabilities. This assessment also identifies opportunities to integrate this MJHMP into future planning, policies, or programs to weave mitigation efforts into daily operations and address hazard problems wholistically. Capabilities are categorized into four groups and include various mechanisms. ▪ Planning and Regulatory Capabilities: Existing long-range plans, emergency response plans, hazard-specific plans, land use policies, and building and development standards. ▪ Administrative and Technical Capabilities: Available expertise in emergency services, engineering, grant management, and community planning.
▪ Fiscal Capabilities: Budgetary capacity, taxing authority, grants, and other funding mechanisms that can support mitigation projects.
▪ Outreach and Education Capabilities: Existing programs for providing technical assistance, community education, public warnings, and stakeholder engagement.

A full description of the process used to develop the capabilities assessment is provided in Volume 1, Section

2.3.3. This capabilities and opportunities assessment for the City of Napa lists the various types of capabilities along with how they have been, currently are, or will in the future be integrated into hazard mitigation planning efforts. The three “HMP Integration” columns that identify the capability’s status and usage are color-coded with green, yellow, or orange shading to communicate the following:
▪ Status: If the capability is present at all and what level of use it has generally. ▪ Current Mitigation Use: If the capability is currently being used in mitigation efforts, specifically, and at what level.
▪ Future Opportunity: If there is a future opportunity to integrate the capability into mitigation efforts and at what level.

Summary of Capabilities & Opportunities
This Capabilities and Opportunities Assessment for the City of Napa summarizes the various types of capabilities it has for hazard mitigation currently. The assessment also identifies opportunities to integrate, expand, and improve the city’s capabilities for future hazard mitigation. Table 3-17 provides a comprehensive list of capabilities and identifies the current status, current mitigation use, and future opportunities.

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Planning & Regulatory
The City of Napa has strong planning and regulatory capabilities that support hazard risk reduction and resilient development. The City enforces the California Building Code (Title 24) through Title 15 of the Napa Municipal Code, along with locally adopted ordinances addressing floodplain management, hillside development, watercourse setbacks, stormwater quality control, water conservation, and seismic safety.

These regulations are implemented through zoning, subdivision, and site plan review processes, ensuring that hazard considerations are integrated into development decisions.

Growth management is guided by the City of Napa 2040 General Plan, including the Land Use and Community Design Element and the Safety and Noise Element, which address geologic, seismic, flood, wildfire, and climate-related hazards. Capital investments are prioritized through the City’s five-year Capital Improvement Program (CIP), which includes projects related to water, stormwater, transportation, and public facilities that enhance resilience. The City also maintains a range of hazard reduction programs, including stormwater management and erosion control (enforced through Chapter 8.36), water conservation regulations (Chapter 13.09), weed abatement, and public outreach initiatives such as Flood Awareness Week and Ready Napa County programs.

The City participates in the National Flood Insurance Program (NFIP) and enforces local floodplain management regulations through Chapter 17.38 (Floodplain Management Overlay District), supported by FEMA Flood Insurance Studies and updated mapping. Napa also participates in the Community Rating System (CRS) and maintains a Class 7 rating, reflecting an advanced level of floodplain management and public outreach. Elevation certificates, floodplain permitting, and insurance education are administered through the Community Development Department.

While overall regulatory capacity is strong, some areas present opportunities for enhancement, including continued integration of environmental justice considerations, expansion of non-structural seismic safety programs, and increased public awareness of hazard risks and mitigation actions.

Future integration of the MJHMP will occur through various processes and mechanisms outlined across multiple mitigation actions (Table 3-18). Key opportunities for future hazard mitigation integration with the City of Napa’s existing planning mechanisms include incorporating the updated risk assessment, hazardspecific vulnerability findings, and projected climate change impacts into the Enhanced Pre- & PostDisaster Coordination (ma-AH-CN-8), Unified Community Hazard Education & Preparedness Program (maAH-CN-3), Communications System Resilience (ma-AH-CN-0), Flood Mapping & Risk Communication Updates (ma-FL-CN-28), and Napa River Flood Project & Residual Risk Reduction (ma-FL-CN-23).

Administrative & Technical
The City of Napa has strong administrative and technical capacity to support hazard mitigation planning, implementation, and coordination across departments. Core functions related to planning, development review, engineering, and infrastructure are managed by the Community Development Department and CAL OES SUBMITTAL - JUNE 2026
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Public Works Department, including Planning, Building, Development Engineering, and Transportation Engineering divisions.

The City has access to qualified personnel in key functional areas, including community planning, land development review, construction engineering, transportation planning, and natural resource management. The Building Division administers building codes and safety standards, while the Public Works Director serves as the Floodplain Administrator. Emergency management functions are coordinated through the Fire Department and Office of Emergency Services, ensuring alignment between preparedness, response, and recovery activities.

Technical capabilities are supported by GIS resources within Public Works and Community Development, as well as coordination with Napa County GIS services. While the City maintains strong baseline capacity, certain functions—such as resiliency planning, public outreach, and grant management—are currently distributed across departments rather than supported by dedicated staff. This shared approach is effective for current operations but represents an opportunity to expand capacity as climate adaptation and mitigation efforts grow.

Warning Systems & Services
The City of Napa has well-established warning and emergency communication capabilities to notify residents, businesses, and visitors of hazardous conditions. The primary system is the Alert Napa County emergency notification system (Everbridge), which provides real-time alerts related to flooding, wildfire, earthquakes, severe weather, and other emergencies.

Emergency information is also disseminated through City and Fire Department social media platforms, websites, and coordinated regional messaging. These systems are designed to provide redundancy and ensure that critical information reaches a broad audience, including during rapidly evolving incidents. The City’s warning systems support all major hazard types and are integrated with countywide emergency response efforts.

Fiscal
The City of Napa has strong fiscal capacity to support hazard mitigation through a combination of local funding mechanisms, fees, and financing tools. Utility fees for water and wastewater services support infrastructure reliability and improvements related to drought resilience and system capacity. Development impact fees contribute to funding for stormwater infrastructure, transportation improvements, fire protection, and other public services necessary to support safe growth.

The City maintains access to financing mechanisms including general obligation bonds and special tax or revenue bonds, which can be used to fund large-scale capital projects. The Capital Improvement Program (CIP), adopted as part of the annual budget process, prioritizes investments in infrastructure that support public safety and hazard mitigation.

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Additional funding sources include Community Development Block Grants (CDBG), which can support housing rehabilitation and infrastructure improvements benefiting vulnerable populations. While tools such as benefit assessments and special-purpose taxes are not currently widely utilized, they represent potential opportunities for expanding hazard mitigation funding in the future. Stormwater-related fees and drainage plan review processes also contribute to funding for localized flood mitigation.

Education & Outreach
The City of Napa has strong education and outreach capabilities that support public awareness, preparedness, and risk reduction. The City maintains a website with hazard-specific information related to emergency preparedness, floodplain management, wildfire prevention, and climate action. Social media platforms, including those managed by the City and Fire Department, are actively used to disseminate information and provide updates during emergencies.

The City participates in annual public safety and preparedness events, including Fire Prevention Week, Flood Awareness Week, the Great California ShakeOut, and Ready Napa County initiatives. Communitybased preparedness is supported through programs such as the Community Emergency Response Team (CERT) and partnerships with organizations including Napa Valley COAD and the Napa Communities Fire Safe Council.

City staff provide technical assistance to the public through multiple channels, including phone, email, and web-based inquiries, particularly for floodplain regulations, development standards, and emergency preparedness. While digital outreach is strong, printed materials and in-person resources are more limited, representing an opportunity to expand engagement with populations that may have reduced access to online information. Additional opportunities include expanding Firewise participation and enhancing targeted outreach to vulnerable populations.

ASSESSMENT LEGEND
HMP Integration
Status Current Mitigation Use Future Opportunity
Currently in use or present. Used widely for mitigation. Opportunity to expand and integrate. (Sort of) Seldomly used or limited
presence.

Limited use in mitigation
planning.

Limited opportunity to expand and
integrate.
(No) Not present or available. Not used in mitigation planning. No opportunity to expand or integrate.

Table 3-17: City of Napa Capabilities and Opportunities Assessment CAL OES SUBMITTAL - JUNE 2026
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HMP Integration Notes / Additional Detail
Resource Status
Current
Mitigation
Use
Future
Opportunity
Planning and Regulatory
Capabilities
Construction and Future
Development Regulations
Building Codes Green Green Green California Building Code (California Code of Regulations, Title 24) adopted under Ch 15.04
BCEGS Rating 0 0 0
Public Protection (ISO Class) 0 0 0
Hazard-Related Development
Standards
Green Green Green
Floodplain Management Overlay District (Ch 17.38),
Hillside Overlay District (Ch 17.40), Water Setback
Overlay District (Ch 17.50), Rehabilitation and
Abatement of Existing Seismically Unsafe Buildings
(Ch 15.110), Water Conservation Regulations (Ch 13.09), Storm Water Quality Control (Ch 8.36), and Weed
Abatement (Ch 8.24)
Zoning Ordinance
Green Green Green
Title 17 (Zoning) implements land-use and siting
standards, floodplain management regulations, and
hillside regulations
Hazard-Specific Ordinance
Green Green Green
Floodplain Management Overlay District (Ch 17.38),
Hillside Overlay District (Ch 17.40), Water Setback
Overlay District (Ch 17.50), Rehabilitation and
Abatement of Existing Seismically Unsafe Buildings
(Ch 15.110), Water Conservation Regulations (Ch 13.09), Storm Water Quality Control (Ch 8.36), and Weed
Abatement (Ch 8.24)
Growth Management Ordinance
Green Green Green City of Napa 2040 General Plan Land Use and Community Design Element
Hazard Reduction Programs
(Annually Conducted)
Capital Improvements Program
(CIP) or Plan Green Green Green 5-yr CIP covers hazard reduction projects including for water, stormwater, streets, and facilities Erosion/Sediment Control
Program Green Green Green Ch 8.36 Storm Water Quality Control; enforced through SWPPP and NPDES permitting Hazard-Related Public Outreach
Program Green Green Green Flood Awareness Week, weed abatement notices, ReadyNapa/County OES programs Urban Water Management Plan Green Green Green Updated 2021; integrates drought, water reliability, and conservation planning
Stormwater Management
Program (Annual Inspections) Green Green Green
Conducted by Public Works Dept; enforced through
Ch 8.36 Storm Water Quality Control, SWPPP and
NPDES permitting
Seismic Safety Program (Nonstructural) Yellow Yellow Green Earthquake preparedness information via City
website; Ch 15.11 Rehabilitation and Abatement of
Existing Seismically Unsafe Buildings
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HMP Integration Notes / Additional Detail
Resource Status
Current
Mitigation
Use
Future
Opportunity
Earthquake Modernization Plan
(Building Safety) Green Green Green
CIP projects for City buildings; Ch 15.11 Rehabilitation and Abatement of Existing Seismically Unsafe
Buildings
Hazard Plans
General Plan Safety Element
Green Green Green
City of Napa 2040 General Plan Safety and Noise
Element addresses geologic, seismic, flood, fire,
hazardous materials, and climate hazards
Site Plan Review Requirements Green Green Green Ch 17.62 Design Review Permits General Plan Environmental
Justice Element Yellow Yellow Yellow No standalone element but integrated throughout 2040 General Plan; Public Health and Equity Element
Community Wildfire Protection
Plan (CWPP) Green Green Green 2021 Napa County CWPP
Economic Development Plan Green Green Green City of Napa 2040 General Plan Economic Development Element
Floodplain Management Plan Green Green Green 2020 HMP (to be replaced by this update); City of Napa 2040 General Plan Safety and Noise Element
Stormwater Management Plan
Green Green Green
Stormwater and drainage management implemented
by Public Works Dept, Engineering Division, and
through NPDES permit; includes annual inspections
and BMP enforcement
Emergency Operations Plan Green Green Green EOP maintained by Fire Dept and OES Climate Action Plan Green Green Green Napa County Regional Climate Action and Adaptation Plan (RCAAP)
Climate Vulnerability Assessment Green Green Green Napa County RCAAP includes assessment Urban Greening Plan
Green Green Green
2024 Urban Forestry Management Plan; City of Napa
2040 General Plan Natural Resources, Climate
Change and Sustainability, and Community Services,
Parks, and Recreation Elements
Ground Water Management
Planning / Plans Green Green Green Maintained by Napa County Groundwater Sustainability Agency; 2020 UWMP National Flood Protection
Program (NFIP)
Floodplain Management
Regulations Green Green Green Ch 17.38 Floodplain Management Overlay District Flood Insurance Education and
Technical Assist. Green Green Green City website provides insurance and preparedness information; Flood Awareness Week
Flood Insurance Study Green Green Green 2016 FEMA FIS 06055CV000C Elevation Certificates Green Green Green Maintained by CRS Coordinator Flood Hazard Mapping / ReMapping Green Green Green FEMA FIRMs, 2008-2016 Community Rating System (CRS) Green Green Green Participating since 2001; Class 7 Administrative and Technical
Community Planning and
Development Services
Community Planner Green Green Green Community Development Dept, Planning Division CAL OES SUBMITTAL - JUNE 2026
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HMP Integration Notes / Additional Detail
Resource Status
Current
Mitigation
Use
Future
Opportunity
Planner/Engineer (Land
Development) Green Green Green Public Works Dept, Development Engineering Division Engineer/Professional
(Construction) Green Green Green Public Works Dept, Engineering Division Planner/Engineer/Scientist
(Natural Hazards) Green Green Green Parks and Recreation Dept Transportation Planner Green Green Green Public Works Dept, Transportation Engineering Division
Resiliency Planner Yellow Yellow Green No dedicated staff; shared role in Community Development Dept, Planning Division
Building Code Official (Full time or
Augmented) Green Green Green Community Development Dept, Building Division Floodplain Administrator Green Green Green Public Works Dept Director Fire Marshal Green Green Green Napa City Fire Department Dedicated Public Outreach
Personnel Yellow Yellow Green
The city has a dedicated Personnel and Media
Relations Manager and an Analyst \ and various
departments also have their own outreach personnel
GIS Specialist and Capability Green Green Green GIS capacity in Public Works and Community Development Depts; supported by Napa County GIS
Emergency Manager Green Green Green Fire Department/OES; coordination with County OES Dedicated Grant Manager, Writer,
or Specialist Yellow Yellow Green Finance Dept, but no dedicated staff; shared across departments
Other

N/A N/A N/A
Warning Systems/Services
General Green Green Green Alert Napa County / Everbridge Emergency Notification Service (formerly Nixle)
Flood Green Green Green Alert Napa County / Everbridge Emergency Notification Service (formerly Nixle)
Tornado Green Green Green Alert Napa County / Everbridge Emergency Notification Service (formerly Nixle)
Wildfire Green Green Green Alert Napa County / Everbridge Emergency Notification Service (formerly Nixle)
Geological Hazards Green Green Green Alert Napa County / Everbridge Emergency Notification Service (formerly Nixle)
Fiscal Capabilities
Financial Resources for
Hazard Mitigation
Levy Taxes for Specific Purposes
Yellow Yellow Yellow
Not consistently applied, but can place special tax
measures on ballot for specific purposes (e.g., sales
tax for public safety)
Utilities Fees Green Green Green Water service fees; sewer provided by Napa Sanitation District
Benefit assessments Orange Orange Yellow Not currently in use; future opportunity CAL OES SUBMITTAL - JUNE 2026
Item #6.5.

HAZARD MITIGATION PLAN 2026 UPDATE

NAPA COUNTY
NAPA COUNTY | HAZARD MITIGATION PLAN 2026 UPDATE
3-96
HMP Integration Notes / Additional Detail
Resource Status
Current
Mitigation
Use
Future
Opportunity
Community Development Block
Grants Yellow Yellow Green Received via HUD; can support hazard-related housing rehabilitation and infrastructure System Development Fee
Green Green Green
Impact fees collected for storm drain infrastructure,
street improvement, fire and paramedic
development, affordable housing, etc.

General Obligation Bonds to Incur
Debt Green Green Green General obligation bonds are available financing tools Special Tax Bonds to Incur Debt Green Green Green Special tax/revenue bonds are authorized for specific projects
Withheld Spending in HazardProne Areas Green Green Green General Plan policies restrict development in hazardprone areas Stormwater Service Fees Orange Orange Green No fee collected currently Capital Improvement Project
Funding Green Green Green CIP adopted; tied to annual budget Education / Outreach
Capabilities
Education/Outreach
Resources
Website Dedicated to Hazard
Topics Green Green Green
City website provides hazard-specific guidance and
information on emergency preparedness, fire
prevention, floodplain management, and climate
action
Dedicated Social Media Green Green Green City and Fire Department maintain active Facebook, Twitter/X, and Instagram accounts
Local Citizen Groups That
Communicate Hazard Risks Green Green Green Napa Valley COAD (Community Organizations Active in Disaster) and neighborhood associations Hazard Info. Avail. at Library/
Planning Desk Yellow Yellow Green Limited printed materials at City Hall and Countylibrary; hazard info mostly digital Annual Public Safety Events
Green Green Green
Fire Prevention Week, Flood Awareness Week,
Earthquake ShakeOut, and Ready Napa County
events
Ability to Field Public Tech.

Assistance Requests Green Green Green
City departments respond to hazard-related inquiries
by phone, email, or web forms; Public Works and Fire
provide direct technical assistance
Public Safety Newsletters or
Printed Outreach Yellow Yellow Green City provides occasional newsletters and flyers; most outreach digital Community Emergency Response
Team (CERT) Green Green Green City of Napa and Napa County CERTs Fire Safe Councils Green Green Green Fire Safe Council and others through Napa Communities Firesafe Foundation
Firewise Orange Orange Green Not currently designated; firewise communities in surrounding area
StormReady Green Green Green StormReady designated
Resource Conservation Districts Green Green Green Napa County RCD provides outreach on wildfire, drought, and other hazard topics
Other N/A N/A N/A
CAL OES SUBMITTAL - JUNE 2026
Item #6.5.

NAPA COUNTY | HAZARD MITIGATION PLAN 2026 UPDATE
HAZARD MITIGATION PLAN 2026 UPDATE

NAPA COUNTY
3-97
City of Napa Mitigation Action Plan
Napa’s mitigation
actions were developed
through a collaborative
process informed by the
updated risk
assessment, local
priorities, and extensive
stakeholder
engagement. As part of
this 2026 MJHMP
update, the city
reviewed mitigation
actions from its prior
Local Hazard Mitigation
Plan to determine
which actions to carry
forward, which to
consolidate, and where
entirely new strategies
were required. This
careful evaluation ensured that the updated action plan builds upon past commitments while also responding to current risks and future challenges.

The plan addresses Napa’s most significant hazards, including wildfire, dam failure, flood, earthquake, drought, severe weather, extreme heat and climate change. Each mitigation action is designed to align with FEMA’ s hazard mitigation guidance and the requirements of the Disaster Mitigation Act of 2000. Where appropriate, overlapping or redundant actions were consolidated into broader, more comprehensive strategies that improve clarity, increase feasibility, and strengthen regional coordination.

The mitigation action prioritization method used by all participating jurisdictions is described in Volume 1, Section 4. Each action specific to City of Napa is documented in Table 3-18, which identifies the responsible department, implementation timeframe, potential funding sources, and resources required to complete the action. Each action is also assigned a unique alphanumeric identifier (see Figure 3-26) that links the strategy to its associated hazard and supports consistent monitoring and reporting.

Figure 3-26: Mitigation Action Number Key
CAL OES SUBMITTAL - JUNE 2026
Item #6.5.

HAZARD MITIGATION PLAN 2026 UPDATE

NAPA COUNTY
NAPA COUNTY | HAZARD MITIGATION PLAN 2026 UPDATE
3-98
Table 3-18: City of Napa Mitigation Action Plan
Mitigation No. Hazard
Type
SubHazardMitigation
Type
Year Primary
Agency
Title Description Responsible
Party
Estimated
Cost
Estimated
Benefit
Time
Frame
HMA
Activity
Type
Potential Grant
Source
Priority Related Problem Statements
ma-AH-CN-0 All Hazard PE&A - Public
Education &
Awareness ,
ES -
Emergency
Services
2015 City of
Napa
Communications
System
Resilience
Improve and harden the City’s public alerting,
radio, and data systems (including back-up
communications and translation capacity) to
maintain connectivity during hazard and other
emergency events, with a focus on reaching
vulnerable populations.

Fire Department,
IT Department,
Police
Department
High High 3-5 Years Project HMGP / BRIC ,
EMPG
High ps-WF-CN-13, ps-DF-CN-41,
ps-DF-CN-42, ps-AH-CN-47,
ps-CC-CN-4, ps-EQ-CN-6
ma-AH-CN-3 All Hazard PE&A - Public
Education &
Awareness
2015 City of
Napa
Unified
Community
Hazard
Education &
Preparedness
Program
Consolidate and modernize all City outreach,
education, and public awareness activities into
a single, coordinated program that provides
guidance and information on assistance
resources for earthquake, wildfire, flood, severe
weather, extreme heat, drought, dam failure,
and climate-change-driven hazards. Activities
include education campaigns, website
enhancements, hazard-specific toolkits
(business continuity, household retrofits,
defensible space, water conservation),
evacuation route and shelter messaging, and
targeted outreach for vulnerable populations
(seniors, mobile home parks, renters, lowincome households, unhoused populations).

Fire Department Low Medium 1-3 Years 5% Internal
Funding , N/A
High ps-EQ-CN-10, ps-CC-CN-1, psEH-CN-2, ps-CC-CN-3, ps-DRCN-31, ps-FL-CN-26, ps-FLCN-27, ps-CC-CN-4, ps-CCCN-19, ps-DF-CN-43, ps-DRCN-33, ps-EQ-CN-7, ps-FLCN-22, ps-SW-CN-34, ps-WFCN-12 ma-AH-CN-7 All Hazard PE&A - Public
Education &
Awareness ,
ES -
Emergency
Services
2015 City of
Napa
Expanded &
Improved Shelter
Network
In collaboration with the County and other
municipalities, expand and improve the shelter
network with ADA-compliant facilities,
adequate air filtration and cooling equipment,
back-up power, options for pets, and
transportation strategies for vulnerable
populations during extreme heat, prolonged
smoke, and other hazard events, with a focus
on seniors, households without AC, and people
experiencing homelessness.

Economic
Development
Dept
High Medium Ongoing Project HMGP / BRIC ,
EMPG , Internal
Funding
Medium ps-FL-CN-27, ps-WF-CN-12,
ps-EH-CN-2, ps-EH-CN-17, psFL-CN-22, ps-DF-CN-43, psCC-CN-4 ma-AH-CN-8 All Hazard PRV -
Prevention
2015 City of
Napa
Enhanced Pre- &
Post-Disaster
Coordination
Establish the position of Emergency Manager
and, in coordination with County Planning,
Building, and OES, improve procedures for
assessing damage after a disaster event,
including inspecting and tagging structures for
public occupancy and ensuring compliance
with NFIP requirements.

Building /
Economic
Development
Dept
Low Medium 1-3 Years Capacity /
Capability
Building
EMPG , Internal
Funding
Medium ps-EQ-CN-8, ps-DF-CN-44, psAH-CN-47, ps-CC-CN-4, psDF-CN-41, ps-EQ-CN-5, ps-FLCN-20, ps-SW-CN-39, ps-WFCN-14 ma-DF-CN-52 Dam
Failure
PRV -
Prevention ,
ES -
Emergency
Services
2021 City of
Napa
Dam Failure
Planning &
Coordination
Integrate dam-failure risk and response into the
City and County EOP, clarify roles and
evacuation priorities, and improve coordination
with critical facility operators in mapped dam
inundation areas.

Fire Department Low Medium 1-3 Years Capacity /
Capability
Building

CDBG DRI ,
EMPG , Internal
Funding
High ps-DF-CN-41, ps-DF-CN-42,
ps-DF-CN-43, ps-DF-CN-44
ma-DR-CN-16 Drought SP - Structural
Projects
2015 City of
Napa
DroughtResilient Water
Supply
Strengthen long-term water supply reliability
through diversified supply, storage
optimization, interties, and operational changes
that account for more frequent and severe
drought. Incorporate recommendations from
the Napa Valley Drought Contingency Plan and
update the Urban Water Management Plan to
reflect supply resilience improvements.

Utilities
Department
High High 5-10 Years Project HMGP / BRIC ,
Internal
Funding
High ps-EH-CN-0, ps-DR-CN-29,
ps-DR-CN-32, ps-DR-CN-31,
ps-DR-CN-33, ps-CC-CN-4
CAL OES SUBMITTAL - JUNE 2026
Item #6.5.

NAPA COUNTY | HAZARD MITIGATION PLAN 2026 UPDATE
HAZARD MITIGATION PLAN 2026 UPDATE

NAPA COUNTY
3-99
Mitigation No. Hazard
Type
SubHazardMitigation
Type
Year Primary
Agency
Title Description Responsible
Party
Estimated
Cost
Estimated
Benefit
Time
Frame
HMA
Activity
Type
Potential Grant
Source
Priority Related Problem Statements
ma-EQ-CN-18 Earthquake PPRO -
Property
Protection ,
PE&A - Public
Education &
Awareness
2015 City of
Napa
Seismic Safety
Support Program
Review feasibility of and consider the
development of a program to encourage the
retrofit seismically vulnerable public and
private structures, including historic downtown
buildings, multi-family housing, mobile home
parks, schools, and community facilities.

Community
Development
Department
High High 3-5 Years Capacity /
Capability
Building
HMGP / BRIC Medium ps-EQ-CN-5, ps-EQ-CN-5, psEQ-CN-7
ma-EQ-CN-20 Earthquake SP - Structural
Projects
2015 City of
Napa
Lifeline
Infrastructure
Seismic
Hardening
Upgrade water, wastewater, and critical electric
infrastructure to withstand major earthquakes,
including fault-crossing pipeline replacements,
flexible joints, valve and pump redundancy, and
backup power at key nodes.

Utilities
Department
High High 3-5 Years Project HMGP / BRIC Medium ps-EQ-CN-6, ps-EQ-CN-5 ma-FL-CN-23 Flood PRV -
Prevention ,
SP - Structural
Projects
2015 City of
Napa
Napa River Flood
Project &
Residual Risk
Reduction
In cooperation with NCFCWCD, complete
remaining phases of the Measure A Napa River
Flood Project and implement complementary
projects (pump stations, detention, localized
drainage improvements) to protect critical
facilities and neighborhoods that remain at risk
of flood hazards.

Community
Development
Department,
Utilities
Department
High High Ongoing Project HMGP / BRIC ,
FMA
High ps-FL-CN-20, ps-FL-CN-21,
ps-FL-CN-22, ps-CC-CN-19,
ps-FL-CN-28, ps-FL-CN-23
ma-FL-CN-28 Flood PRV -
Prevention ,
PE&A - Public
Education &
Awareness
2015 City of
Napa
Flood Mapping &
Risk
Communication
Updates
In collaboration with the County and FCWCD,
update flood hazard mapping to incorporate
completed projects, sea-level rise, atmospheric
river events, and tidal influences, and improve
flood warning systems with enhanced stream
sensor coverage and free NOAA weather radios
to high risk, limited income households in flood
zones.

County Public
Works, City
Utilities
Department
Medium Medium 1-3 Years Project HMGP / BRIC ,
FMA , Internal
Funding
Medium ps-CC-CN-19, ps-FL-CN-23,
ps-FL-CN-22, ps-FL-CN-20,
ps-CC-CN-4
ma-SW-CN-24 Severe
Weather
Heavy Rain NRP - Natural
Resource
Protection , SP
- Structural
Projects
2015 City of
Napa
Drainage
Improvement
Projects
Implement targeted drainage infrastructure
upgrades at localized flooding hotspots (e.g.,
Trower, Valencia, Yosemite, Diablo, Glacier) to
reduce street flooding and hazardous travel
conditions during heavy rain events, including
nature-based improvements.

Community
Development
Department,
Utilities
Department,
Public Works
Department
High High 3-5 Years Project HMGP / BRIC ,
FMA
High ps-FL-CN-20, ps-FL-CN-21,
ps-CC-CN-19, ps-FL-CN-28,
ps-SW-CN-34, ps-SW-CN-35,
ps-CC-CN-4
ma-SW-CN-58 Severe
Weather
High Wind NRP - Natural
Resource
Protection , ES
- Emergency
Services
2021 City of
Napa
Urban Forest &
Windstorm Risk
Reduction
Program
Implement proactive tree risk assessments,
pruning, removals, and replanting with
appropriate species that do not interfere with
utilities along major corridors and evacuation
routes to reduce outages, blocked roads, and
damage during high-wind events.

Administration,
Public Works
Department,
Parks and
Recreation
Department
Medium High 3-5 Years Capacity /
Capability
Building
HMGP / BRIC Medium ps-SW-CN-35, ps-SW-CN-39,
ps-SW-CN-36, ps-CC-CN-4
ma-WF-CN-41 Wildfire NRP - Natural
Resource
Protection
2015 City of
Napa
Fuel
Management
Projects &
Maintenance
Program
Establish a program to ensure ongoing
maintenance of key treatment areas and
conduct new fuel management projects in City
parks and open spaces (e.g., Westwood Hills
and Alston).

Fire Department Medium High 1-3 Years Capacity /
Capability
Building

HMGP / BRIC ,
AFG
Medium ps-WF-CN-12, ps-CC-CN-18,
ps-WF-CN-14, ps-WF-CN-11,
ps-CC-CN-4
ma-WF-CN-43 Wildfire NRP - Natural
Resource
Protection , SP
- Structural
Projects
2015 City of
Napa
Water Resources
Protections
Implement coordinated fuels management,
access improvements, and structural hardening
projects to protect water sources, watersheds,
and treatment and conveyance systems from
wildfire and post-fire impacts (debris flows,
erosion). Coordinate protection efforts within
the Lake Hennessey and Lake Milliken
watersheds to protect drinking water supplies
from water quality impacts.

Utilities
Department
High High 3-5 Years Project HMGP / BRIC ,
AFG
High ps-WF-CN-11, ps-WF-CN-16,
ps-WF-CN-12, ps-WF-CN-14,
ps-CC-CN-4
CAL OES SUBMITTAL - JUNE 2026
Item #6.5.

HAZARD MITIGATION PLAN 2026 UPDATE

NAPA COUNTY
NAPA COUNTY | HAZARD MITIGATION PLAN 2026 UPDATE
3-100

PAGE INTENTIONALLY LEFT BLANK
CAL OES SUBMITTAL - JUNE 2026
Item #6.5.

NAPA COUNTY | HAZARD MITIGATION PLAN 2026 UPDATE
HAZARD MITIGATION PLAN 2026 UPDATE

NAPA COUNTY
3-1
Status of Previous Mitigation Actions
In 2020, the City of Napa adopted its previous FEMA-approved HMP. This 2026 MJHMP represents a comprehensive update from that previous plan, as discussed in Volume 1, Section 1.5. Table 3-19 provides status updates for all of the previous mitigation actions in the City of Napa HMP, from which many of the mitigation actions in Table 3-18 were sourced and revised.

Table 3-19: City of Napa Status of Previous Mitigation Actions Mitigation
No.

Hazard
Type Status Year Primary Agency Title/Description Reason Completed/ Cancelled ma-AH-CN-0 All Hazard Ongoing 2015 City of
Napa
Communications System
Resilience Revised
ma-AH-CN-3 All Hazard Ongoing 2015 City of
Napa
Unified Community Hazard
Education & Preparedness Program Revised
ma-AH-CN-7 All Hazard Ongoing 2015 City of
Napa
Expanded & Improved Shelter
Network Revised
ma-AH-CN-8 All Hazard Ongoing 2015 City of
Napa
Enhanced Pre- & Post-Disaster
Coordination Revised
ma-DF-CN52Dam
Failure Ongoing 2021 City of Napa
Dam Failure Planning &
Coordination Revised
ma-DR-CN16 Drought Ongoing 2015 City of
Napa Drought-Resilient Water Supply Revised
ma-EQ-CN18 Earthquake Ongoing 2015 City of
Napa Seismic Safety Support Program Revised
ma-EQ-CN20 Earthquake Ongoing 2015 City of
Napa
Lifeline Infrastructure Seismic
Hardening Revised
ma-FL-CN23 Flood Ongoing 2015 City of
Napa
Napa River Flood Project &
Residual Risk Reduction Revised
ma-FL-CN28 Flood Ongoing 2015 City of
Napa
Flood Mapping & Risk
Communication Updates Revised
ma-FL-CN24 Flood Ongoing 2015 City of
Napa Drainage Improvement Projects Revised
ma-EW-CN58Severe
Weather Ongoing 2021 City of Napa
Urban Forest & Windstorm Risk
Reduction Program Revised
ma-WF-CN41 Wildfire Ongoing 2015 City of
Napa
Fuel Management Projects &
Maintenance Program Revised
ma-WF-CN43 Wildfire Ongoing 2015 City of
Napa Water Resources Protections Revised
ma-AH-CN-1 All Hazard Completed 2015 City of
Napa Build an alternate EOC Back-up EOC established at Las Flores Community Center ma-AH-CN-2 All Hazard Completed 2015 City of
Napa
Create a Remote Workers
Infrastructure Remote access established
ma-AH-CN-4 All Hazard Completed 2015 City of
Napa
Maintain and equip an Emergency
Operation Center(EOC) for
immediate availability in the event
of a disaster.

Back-up power installed and
back-up EOC established at Las
Flores Community Center
CAL OES SUBMITTAL - JUNE 2026
Item #6.5.

HAZARD MITIGATION PLAN 2026 UPDATE

NAPA COUNTY
NAPA COUNTY | HAZARD MITIGATION PLAN 2026 UPDATE
3-2
Mitigation
No.

Hazard
Type Status Year Primary Agency Title/Description Reason Completed/ Cancelled ma-AH-CN57 All Hazard Completed 2021 City of
Napa
Construct backup generators at
critical facilities (fire stations,
hospital) and sheltering locations
to respond to hazard events in loss
of power.

Permanent back-up power in
place for key facilities
ma-AH-CN-5 All Hazard Cancelled 2015 City of
Napa
Work with local businesses to
prepare Emergency Preparedness
Plans by working with other
agencies and advocacy
organizations to distribute to and
assist businesses with the
preparation of plans in the case of
disaster.
ma-AH-CN-3, ma-AH-CN-5, maAH-CN-7, ma-FL-CN-25, ma-FLCN-29, ma-FL-CN-30, ma-DR-CN54, ma-EQ-CN-17, ma-WF-CN-42, ma-WF-CN-44, ma-WF-CN-45,
ma-PN-CN-31, ma-PN-CN-32 &
ma-AH-CN-13 combined and
revised
ma-AH-CN-6 All Hazard Cancelled 2015 City of
Napa
Identify and develop programs to
be instituted to assist residents to
prepare for and recover from a
disaster
Ongoing work of the City; also
included within MA-AH-CN-3
ma-AH-CN-9 All Hazard Cancelled 2015 City of
Napa
Establish the position of Disaster
Coordinator for the City of Napa
ma-AH-CN-8, 9 & 13 Revised
ma-AH-CN10All Hazard Cancelled 2015 City of
Napa
Identify critical businesses and
prepare emergency response
plans to protect against economic
loss and speedy recovery
Included within MA-AH-CN-6
ma-AH-CN11All Hazard Cancelled 2015 City of
Napa
Develop inventories of specific
types of businesses and buildings
and prepare procedures for postdisaster recovery efforts This action is included in ma-AHCN-8.
ma-AH-CN12All Hazard Cancelled 2015 City of
Napa
Prepare a secondary EOC site Included within MA-AH-CN-1 ma-AH-CN13All Hazard Cancelled 2015 City of
Napa
Develop a program to identify
evacuation routes and procedures
for all sensitive facilities and
implement programs to practice
evacuation and safety maneuvers.
ma-AH-CN-3, ma-AH-CN-5, maAH-CN-7, ma-FL-CN-25, ma-FLCN-29, ma-FL-CN-30, ma-DR-CN54, ma-EQ-CN-17, ma-WF-CN-42, ma-WF-CN-44, ma-WF-CN-45,
ma-PN-CN-31, ma-PN-CN-32 &
ma-AH-CN-13 combined and
revised
ma-CC-CN51All Hazard Cancelled 2021 City of
Napa
Expanded & Improved Shelter
Network
ma-AH-CN-7, ma-CC-CN-51
combined and revised
ma-CC-CN14Climate
Change
Cancelled 2015 City of
Napa
Develop a Climate Action Plan
applicable with state and federal
law
Addressed in Napa County
Regional Climate Action and
Adaptation Plan
ma-DF-CN15Dam
Failure
Cancelled 2015 City of
Napa
Maintain a program on dam safety
and continue to cooperate with the
State Division of Dam Safety in
addressing any needed dam
maintenance or structural
improvements.

Ongoing baseline mitigation
activity
CAL OES SUBMITTAL - JUNE 2026
Item #6.5.

NAPA COUNTY | HAZARD MITIGATION PLAN 2026 UPDATE
HAZARD MITIGATION PLAN 2026 UPDATE

NAPA COUNTY
3-3
Mitigation
No.

Hazard
Type Status Year Primary Agency Title/Description Reason Completed/ Cancelled ma-DR-CN54Drought Cancelled 2021 City of
Napa
Develop a public education
campaign to encourage water
conservation during drought, in
collaboration with the Napa Valley
Drought Contingency Plan Task
Force and Napa Sanitation District.

The intent is to avoid or delay
issuance of water restriction
emergency declarations.
ma-AH-CN-3, ma-AH-CN-5, maAH-CN-7, ma-FL-CN-25, ma-FLCN-29, ma-FL-CN-30, ma-DR-CN54, ma-EQ-CN-17, ma-WF-CN-42, ma-WF-CN-44, ma-WF-CN-45,
ma-PN-CN-31, ma-PN-CN-32 &
ma-AH-CN-13 combined and
revised
ma-DR-CN55Drought Cancelled 2021 City of
Napa
Implement recommendations from
the Napa Valley Drought
Contingency Plan. Incorporate into
the City's Urban Water
Management Plan.
ma-DR-CN-16 & 55 Revised
ma-EQ-CN17Earthquake Cancelled 2015 City of
Napa
Develop a program to educate the
community on the various
methods of retrofitting preearthquake code designed
structures, which would include:
workshops, literature and public
safety announcements.
ma-AH-CN-3, ma-AH-CN-5, maAH-CN-7, ma-FL-CN-25, ma-FLCN-29, ma-FL-CN-30, ma-DR-CN54, ma-EQ-CN-17, ma-WF-CN-42, ma-WF-CN-44, ma-WF-CN-45,
ma-PN-CN-31, ma-PN-CN-32 &
ma-AH-CN-13 combined and
revised
ma-EQ-CN19Earthquake Cancelled 2015 City of
Napa
Building Earthquake Safety
Program
Included within MA-EW-CN-17
ma-EQ-CN21Earthquake Cancelled 2015 City of
Napa
Invest in automation and control
features on AC transmission
pipeline to protect against
catastrophic failures.

Included within MA-EW-CN-20
ma-EQ-CN22Earthquake Cancelled 2015 City of
Napa
Invest in water transmission
pipeline
rehabilitation/replacement to
protect against catastrophic
failures
Included within MA-EW-CN-20
ma-EQ-CN56Earthquake Cancelled 2021 City of
Napa
Encourage privately owned
unreinforced masonry buildings
and critical facilities (e.g. churches,
hotels, other gathering facilities) to
evaluate the ability of the buildings
to withstand earthquakes and to
address any deficiencies identified;
explore a cost-share program to
assist private owners in
conducting seismic retrofits.
ma-EQ-CN-17, 18 & 56 Revised
ma-EW-CN59Extreme
Weather
Cancelled 2021 City of
Napa
Replace dying or dead evergreen
vegetation with wind resistant
vegetation and implement annual
tree trimming program.
ma-EW-CN-58 & 59 combined and
revised
ma-FL-CN25Flood Cancelled 2015 City of
Napa
Improve Countywide flood
surveillance/early warning system
ma-AH-CN-3, ma-AH-CN-5, maAH-CN-7, ma-FL-CN-25, ma-FLCN-29, ma-FL-CN-30, ma-DR-CN54, ma-EQ-CN-17, ma-WF-CN-42, ma-WF-CN-44, ma-WF-CN-45,
ma-PN-CN-31, ma-PN-CN-32 &
ma-AH-CN-13 combined and
revised
CAL OES SUBMITTAL - JUNE 2026
Item #6.5.

HAZARD MITIGATION PLAN 2026 UPDATE

NAPA COUNTY
NAPA COUNTY | HAZARD MITIGATION PLAN 2026 UPDATE
3-4
Mitigation
No.

Hazard
Type Status Year Primary Agency Title/Description Reason Completed/ Cancelled ma-FL-CN26Flood Cancelled 2015 City of
Napa
Complete Soscol Interior Drainage
Project Preliminary Design
ma-FL-CN-24 & 26 combined and
revised
ma-FL-CN27Flood Cancelled 2015 City of
Napa
Continue to apply floodplain
management regulations for
development in the flood plain and
floodway.

Baseline mitigation requirement
ma-FL-CN29Flood Cancelled 2015 City of
Napa
Distribute NOAA weather Radios to
high risk, limited income families
living in flood zones. Develop
program of at cost NOAA radios for
families in the various flood zones
in Napa County. Provide weather
radios to block captains.
ma-AH-CN-3, ma-AH-CN-5, maAH-CN-7, ma-FL-CN-25, ma-FLCN-29, ma-FL-CN-30, ma-DR-CN54, ma-EQ-CN-17, ma-WF-CN-42, ma-WF-CN-44, ma-WF-CN-45,
ma-PN-CN-31, ma-PN-CN-32 &
ma-AH-CN-13 combined and
revised
ma-FL-CN30Flood Cancelled 2015 City of
Napa
Periodically update the Flood
Insurance Rate Maps to reflect the
improvements that have been
completed as part of the Flood
Protection Project.
ma-AH-CN-3, ma-AH-CN-5, maAH-CN-7, ma-FL-CN-25, ma-FLCN-29, ma-FL-CN-30, ma-DR-CN54, ma-EQ-CN-17, ma-WF-CN-42, ma-WF-CN-44, ma-WF-CN-45,
ma-PN-CN-31, ma-PN-CN-32 &
ma-AH-CN-13 combined and
revised
ma-FL-CN49Flood Cancelled 2021 City of
Napa
Implement various flood control
projects after approved Flood
Control Project. For example,
additional pump stations are
needed to increase the
functionality and resilience of the
flood wall along the west side of
the Napa River.
ma-FL-CN-23, 49 & 62 combined
and revised
ma-FL-CN62Flood Cancelled 2021 City of
Napa
Implement the Trower Avenue
Storm Drain Improvements, Phase
II project, which consists of
improvements to alleviate flooding
from heavy rain events along
Valencia Street, Yosemite Street,
Diablo Street and Glacier Drive.
ma-FL-CN-23, 49 & 62 combined
and revised
ma-PN-CN31Pandemic Cancelled 2015 City of
Napa
Coordinate efforts with health
community to respond to
communicable diseases
Not profiled; ma-AH-CN-3, maAH-CN-5, ma-AH-CN-7, ma-FLCN-25, ma-FL-CN-29, ma-FL-CN30, ma-DR-CN-54, ma-EQ-CN-17, ma-WF-CN-42, ma-WF-CN-44,
ma-WF-CN-45, ma-PN-CN-31, maPN-CN-32 & ma-AH-CN-13
combined and revised
ma-PN-CN32Pandemic Cancelled 2015 City of
Napa
Ensure that the city, the hospitals
and the County Health Dept.
coordinate efforts to educate,
prepare for and respond to
outbreaks of communicable
disease
Not profiled; ma-AH-CN-3, maAH-CN-5, ma-AH-CN-7, ma-FLCN-25, ma-FL-CN-29, ma-FL-CN30, ma-DR-CN-54, ma-EQ-CN-17, ma-WF-CN-42, ma-WF-CN-44,
ma-WF-CN-45, ma-PN-CN-31, maPN-CN-32 & ma-AH-CN-13
combined and revised
CAL OES SUBMITTAL - JUNE 2026
Item #6.5.

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3-5
Mitigation
No.

Hazard
Type Status Year Primary Agency Title/Description Reason Completed/ Cancelled ma-PN-CN60Pandemic Cancelled 2021 City of
Napa
Assess and institute necessary
upgrades to critical facilities to
allow for usage during pandemic,
including adequate ventilation and
physical barriers
Not profiled
ma-TR-CN33Terrorism Cancelled 2015 City of
Napa
Provide training for Public Safety
personnel regarding terrorism
Human-caused hazards not
prioritized in this HMP; better
addressed in other plans
ma-TR-CN34Terrorism Cancelled 2015 City of
Napa
Develop training to improve
response to civil unrest and riots
Human-caused hazards not
prioritized in this HMP; better
addressed in other plans
ma-TR-CN35Terrorism Cancelled 2015 City of
Napa
Provide terrorism training Human-caused hazards not
prioritized in this HMP; better
addressed in other plans
ma-TR-CN36Terrorism Cancelled 2015 City of
Napa
Improve response to Mass
Casualty/WMD incidents
Human-caused hazards not
prioritized in this HMP; better
addressed in other plans
ma-TR-CN37Terrorism Cancelled 2015 City of
Napa
Increase agency coordination in
dealing with terrorism
Human-caused hazards not
prioritized in this HMP; better
addressed in other plans
ma-TR-CN38Terrorism Cancelled 2015 City of
Napa
Modify and increase resources to
decrease crime
Human-caused hazards not
prioritized in this HMP; better
addressed in other plans
ma-TR-CN39Terrorism Cancelled 2015 City of
Napa
Purchase an armored citizen
rescue vehicle
Human-caused hazards not
prioritized in this HMP; better
addressed in other plans
ma-TR-CN40Terrorism Cancelled 2015 City of
Napa
Improve support of Napa County
Hazardous Device Team
Human-caused hazards not
prioritized in this HMP; better
addressed in other plans
ma-WF-CN42Wildfire Cancelled 2015 City of
Napa
Continue to support the Napa
Communities Firewise Foundation
in the development of Fire Safe
Councils and implementation of
the 2021 Community Wildfire
Protection Plan
ma-AH-CN-3, ma-AH-CN-5, maAH-CN-7, ma-FL-CN-25, ma-FLCN-29, ma-FL-CN-30, ma-DR-CN54, ma-EQ-CN-17, ma-WF-CN-42, ma-WF-CN-44, ma-WF-CN-45,
ma-PN-CN-31, ma-PN-CN-32 &
ma-AH-CN-13 combined and
revised
ma-WF-CN44Wildfire Cancelled 2015 City of
Napa
Ensure the Fire Department
reviews all building plans in WUI
areas for defensible space,
emergency vehicle access, fire
flow and ignition resistant
construction requirements.
ma-AH-CN-3, ma-AH-CN-5, maAH-CN-7, ma-FL-CN-25, ma-FLCN-29, ma-FL-CN-30, ma-DR-CN54, ma-EQ-CN-17, ma-WF-CN-42, ma-WF-CN-44, ma-WF-CN-45,
ma-PN-CN-31, ma-PN-CN-32 &
ma-AH-CN-13 combined and
revised
ma-WF-CN45Wildfire Cancelled 2015 City of
Napa
Provide an ongoing vegetation
management program such as the
City's Weed Abatement ordinance
to prohibit the spread of wildfire in
ground and aerial fuels and to
assist homeowners in developing
defensible space.
ma-AH-CN-3, ma-AH-CN-5, maAH-CN-7, ma-FL-CN-25, ma-FLCN-29, ma-FL-CN-30, ma-DR-CN54, ma-EQ-CN-17, ma-WF-CN-42, ma-WF-CN-44, ma-WF-CN-45,
ma-PN-CN-31, ma-PN-CN-32 &
ma-AH-CN-13 combined and
revised
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Mitigation
No.

Hazard
Type Status Year Primary Agency Title/Description Reason Completed/ Cancelled ma-WF-CN46Wildfire Cancelled 2021 City of
Napa
Coordinate watershed protection
efforts within the Lake Hennessey
and Lake Milliken watersheds to
protect drinking water supplies
from water quality impacts.
ma-WF-CN-43, 46, 47, 48 & 63
combined and revised
ma-WF-CN47Wildfire Cancelled 2021 City of
Napa
Implement Lake Hennessy Intake
Pump Station
Defensible Space /Construction
Upgrade
ma-WF-CN-43, 46, 47, 48 & 63
combined and revised
ma-WF-CN48Wildfire Cancelled 2021 City of
Napa
Implement Lake Hennessy
Pipeline Protection Project
ma-WF-CN-43, 46, 47, 48 & 63
combined and revised
ma-WF-CN50Wildfire Cancelled 2021 City of
Napa
Implement demonstration fuels
treatment and emergency access
project at Timberhill Park
ma-WF-CN-41, 42, 45, 50 & 61
combined and revised
ma-WF-CN61Wildfire Cancelled 2021 City of
Napa
Maintain Fire Access Roads and
evacuation routes that have been
identified throughout the City of
Napa.
ma-WF-CN-41, 42, 45, 50 & 61
combined and revised
ma-WF-CN63Wildfire Cancelled 2021 City of
Napa
Fund and implement the Milliken
Raw Water Pipeline Hardening
Project
ma-WF-CN-43, 46, 47, 48 & 63
combined and revised
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Section 4. City of St. Helena
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Napa County
2026 Multi-Jurisdictional Hazard Mitigation Plan Update City of St. Helena (SH)
Municipal Annex
Section 4. City of St. Helena.......................................................................................................4-9

4.1 Scope & Purpose .....................................................................................................................................................................4-9

4.2 Jurisdictional Setting...........................................................................................................................................................4-9

4.2.1 Geography & Climate ................................................................................................................................................4-10

4.2.2 Demographics & Vulnerable Populations.........................................................................................................4-12

4.2.3 Economy........................................................................................................................................................................4-28

4.2.4 Growth Trends & Future Development..............................................................................................................4-28

4.3 Planning Process ................................................................................................................................................................ 4-29

4.3.1 Public Input & Draft Review ...................................................................................................................................4-32

4.4 What’s New.............................................................................................................................................................................4-32

4.4.1 Mitigation Activities .................................................................................................................................................4-32

4.4.2 Mitigation Successes................................................................................................................................................4-33

4.5 Risk Assessment................................................................................................................................................................. 4-34

4.5.1 Hazard Screening & Prioritization ......................................................................................................................4-35

4.5.2 Vulnerability to Specific Hazards........................................................................................................................4-39

4.5.3 Climate Change Impacts & Vulnerable Populations....................................................................................4-61

4.5.4 Hazard Problem Statements..................................................................................................................................4-62

4.6 Mitigation Strategy .............................................................................................................................................................4-65

4.6.1 Capabilities & Opportunities................................................................................................................................. 4-66

4.6.2 City of St. Helena Mitigation Action.................................................................................................................. 4-79

4.6.3 Status of Previous Mitigation Actions.............................................................................................................. 4-84 CAL OES SUBMITTAL - JUNE 2026
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List of Figures
Figure 4-1: City of St. Helena Geographic Overview Map..................................................................................................4-11 Figure 4-2: City of St. Helena Median Household Income Map.....................................................................................4-15 Figure 4-3: City of St. Helena Poverty Status Map...............................................................................................................4-16 Figure 4-4: City of St. Helena Housing Occupancy Map...................................................................................................4-17 Figure 4-5: City of St. Helena Dependent Age Groups Map .............................................................................................4-21 Figure 4-6: City of St. Helena Disabled Elderly Map.......................................................................................................... 4-22 Figure 4-7: City of St. Helena Race and Ethnicity Map .................................................................................................... 4-24 Figure 4-8: City of St. Helena Spanish-Speaking Households Map............................................................................. 4-25 Figure 4-9: City of St. Helena CDC Social Vulnerability Index Map ............................................................................ 4-27 Figure 4-10: City of St. Helena Risk Assessment Matrix.................................................................................................. 4-37 Figure 4-11: Exposure Summary – City of St. Helena Wildfire Risk.............................................................................4-41 Figure 4-12: Exposure Summary – City of St. Helena Earthquake Risk (M7.1 Hunting Creek–Berryessa).4-44 Figure 4-13: Exposure Summary – City of St. Helena Earthquake Risk (M6.7 West Napa)................................ 4-45 Figure 4-14: Exposure Summary – City of St. Helena Liquefaction Risk..................................................................4-46 Figure 4-15: City of St. Helena Flood Risk (FEMA Zones and DWR Awareness Zone).........................................4-49 Figure 4-16: Exposure Summary – City of St. Helena Flood Risk (FEMA Zones) .................................................. 4-50 Figure 4-17: Exposure Summary – City of St. Helena Slope Failure Risk................................................................. 4-52 Figure 4-18: Drought Severity Timeline 2000-2024 ............................................................................................................4-55 Figure 4-19: Exposure Summary – City of St. Helena Dam Inundation Zone......................................................... 4-57 Figure 4-20: Mitigation Action Number Key ........................................................................................................................ 4-79 CAL OES SUBMITTAL - JUNE 2026
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List of Tables
Table 4-1: City of St. Helena Population and Households.................................................................................................4-12 Table 4-2: City of St. Helena Income and Poverty ...............................................................................................................4-13 Table 4-3: City of St. Helena Renter- and Owner-Occupied Housing..........................................................................4-14 Table 4-4: City of St. Helena Households with Seniors.....................................................................................................4-18 Table 4-5: City of St. Helena Households with Children...................................................................................................4-19 Table 4-6: City of St. Helena Population with Disabilities and Access to Transportation ................................. 4-20 Table 4-7: City of St. Helena Household Languages .......................................................................................................... 4-23 Table 4-8: City of St. Helena Planning Team and Steering Group Members........................................................... 4-30 Table 4-9: City of St. Helena Planning Team Meetings.....................................................................................................4-31 Table 4-10: City of St. Helena Document Review of Potential Hazards ..................................................................... 4-36 Table 4-11: City of St. Helena Hazards Prioritization Summary.................................................................................... 4-38 Table 4-12: City of St. Helena National Flood Insurance Program Information.....................................................4-48 Table 4-13: Drought Classifications and Impacts ............................................................................................................... 4-54 Table 4-14: Cal-Adapt Extreme Heat Thresholds................................................................................................................ 4-59 Table 4-15: City of St. Helena Hazard Problem Statements............................................................................................ 4-62 Table 4-16: City of St. Helena Capabilities and Opportunities Assessment............................................................. 4-74 Table 4-17: City of St. Helena Mitigation Action Plan ....................................................................................................... 4-82 Table 4-18: City of St. Helena Status of Previous Mitigation Actions .........................................................................4-84 CAL OES SUBMITTAL - JUNE 2026
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Adoption Resolution
To comply with the Federal Disaster Mitigation Act of 2000 (DMA 2000), the St. Helena City Council has officially adopted this 2026 Napa County Multi-Jurisdictional Hazard Mitigation Plan, including Volume 1 in its entirety as well as this Volume 2 municipal annex. The adoption of the MJHMP recognizes the city’s commitment to reducing the impacts of natural hazards within its jurisdiction and across Napa County.

A copy of the city’s adoption record is provided on the following pages. Adoption records for all jurisdictions are summarized in Volume 1, Table ES-1.

ADOPTION RECORD TO BE INSERTED UPON COMPLETION.

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Section 4.City of St. Helena

4.1 Scope & Purpose
This Jurisdictional Annex for the City of St. Helena of the 2026 Napa County Multi-Jurisdictional Hazard Mitigation Plan (MJHMP) details the hazard mitigation planning elements specific to the city’s planning area. The annex is not intended to be a standalone document but appends to and supplements the information contained in the umbrella plan document (Volume 1). As such, all sections of the umbrella plan, including the planning process and other procedural requirements, apply to and were met by the City of St.

Helena. This annex provides additional information specific to the city, with a focus on hazard identification and risk assessment, vulnerability assessment, problem statements, mitigation strategy, and capabilities assessment. Below are the City of St. Helena Points of Contact:

Primary Point of Contact Alternate Point of Contact
City Manager
City of St. Helena
1088 College Avenue
St. Helena, CA 94574
Telephone: (707) 968-2744 ext. 500
email: [email protected]
John Sorensen, Fire Chief
City of St. Helena
1088 College Avenue
St. Helena, CA 94574
Telephone: (707) 486-2882
email: [email protected]

4.2 Jurisdictional Setting
The City of St. Helena sits at the heart of the upper Napa Valley in Napa County in Northern California, approximately 50 miles north of San Francisco. The city is bounded by the Mayacamas Mountains to the west, the Napa Valley to the south and north, and the Howell Mountains to the east. The city is situated along Highways 29 and 128, which provide regional access to other parts of Napa County, as well as Sonoma and Lake Counties. St. Helena is a small town characterized by a mix of residential neighborhoods, a Central Business District, resorts and other visitor-serving commercial business, and wine production facilities.

The St. Helena city limits encompass approximately 4.7 square miles on the Napa Valley floor and are bisected by the Napa River. This varied topography and proximity to a major waterway influences the city’s exposure to natural hazards, including flooding, seismic shaking, wildfire along the wildland–urban interface, and climate change–related impacts such as extreme heat and increased flood risk.

The city operates as a general law city under a council-manager form of government and provides a full range of municipal services, including fire protection, police protection, public works, community development, and water and wastewater services.

In addition to its incorporated boundaries, the city provides water and wastewater services to areas outside the city limits. Under California planning law, these extraterritorial service areas are considered part of the city’s planning area because damage to infrastructure beyond municipal boundaries can directly affect CAL OES SUBMITTAL - JUNE 2026
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public health, safety, and continuity of essential services within St. Helena. The City of St. Helena’s location within Napa County is shown in Figure 4-1.
▪ Year of Incorporation: 1876
▪ 2021 Population: 5,426 (US Census Bureau, 2021)
▪ Population Growth: Slow population growth from founding to 1970s; Moderate population growth since.

4.2.1 Geography & Climate
The City of St. Helena is located in the upper Napa Valley at the base of the Mayacamas Mountains. The city is bisected by the Napa River. Figure 4-1 provides a geographic overview of the city. Hydrologically, St.

Helena is part of the Napa River watershed, which conveys runoff from northern Napa County through the City before discharging into San Pablo Bay. Portions of the City lie near or within historic floodplain areas, particularly adjacent to the Napa River. These low-lying areas are subject to flooding. Stormwater systems throughout the City are designed to manage runoff generated by seasonal precipitation.

The climate in St. Helena and the Napa Valley is warmer than that in the rest of the Bay Area. Nevertheless, in summer, St. Helena and the rest of the Napa Valley are protected from the hot weather of the Central Valley of California by the coastal mountain ranges. The Pacific Ocean provides a source of cool, moist air in the summer, and this steady flow of marine air holds temperatures at a moderate level. The greatest variation in temperature occurs in summer. In St. Helena, average high summer temperatures are in the upper 80's to the mid 90's. Winters are generally mild, but there are occasional cold spells. Average high winter temperatures are in the high 50's to low 60's, while the minimum temperatures are in the upper 20's and 30's. Frost is common during clear, calm mornings in the late fall and winter.

The growing season, which is the period between the last freezing temperature event in spring and the first in fall, ranges from 215 to 260 days in St. Helena. Most of the annual precipitation falls during the period of November through April. The greatest amount of rainfall is expected to range from 0.9 inch in one hour once in two years to 2.1 inches in one hour once in 100 years.

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Figure 4-1: City of St. Helena Geographic Overview Map
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4.2.2 Demographics & Vulnerable Populations
This section describes the demographic characteristics of the City of St. Helena to guide hazard mitigation planning efforts. Natural disasters affect communities both physically and socially, with demographic composition playing a central role in determining how impacts are distributed, particularly among vulnerable groups facing greater challenges in preparedness, response, and recovery. Understanding the area's social and economic landscape also helps assess potential social costs from infrastructure damage, including housing, industry, public facilities, essential services, and transportation.

Exploring local demographic data may help to identify groups and geographic areas with specific vulnerability to hazard events. In the context of all-hazards preparedness and response planning, at-risk individuals (often used interchangeably with “vulnerable populations”) are defined federally as “children, pregnant women, senior citizens, and other individuals who have access or functional needs in the event of a public health emergency.” (42 U.S.C. § 2802(b)(4)(B) (2019)) These populations may include, but are not limited to, individuals who are economically disadvantaged, living with disabilities, dependent on caregivers, from historically marginalized communities, have limited English proficiency or are nonEnglish speaking, lack access to transportation, are experiencing homelessness, or have chronic medical conditions.

Certain populations face greater risk following a natural hazard event due to age, economic mobility, physical disability, geographic location, or a combination of factors. Vulnerability in the face of a hazard event is not a fixed characteristic; the same individual may be at risk for some hazards but not at risk for others. Planning for vulnerable populations in the context of hazard mitigation can help communities to prioritize limited resources where they will be the most effective. Refer to Volume 1, Section 1.4.3, for a more in-depth discussion of planning for vulnerable populations, at-risk individuals with access and functional needs, and environmental justice.

The total population, total number of households, and average household size of the City of St. Helena are presented in Table 4-1, compared to the other municipalities and Napa County. As shown in the table, St.

Helena is the third-largest city in Napa County.

Table 4-1: City of St. Helena Population and Households Area Total Population Total Households (HH) Average HH Size Napa County 137,384 55,588 2.40
City of Napa 79,233 31,666 2.47
City of American Canyon 21,669 5,924 3.64
City of Calistoga 5,191 2,330 2.20
City of St. Helena 5,426 2,963 1.81
Town of Yountville 3,397 1,824 1.45
Source: ACS 5-Year, 2017-2022
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Income & Housing
Economic mobility is one of the most important predictors of natural hazard vulnerability. Low-income residents are more likely to occupy housing which is inadequately maintained or otherwise poorly built to withstand extreme events. For example, mobile or modular homes are more susceptible to damage in earthquakes and floods than other types of residences and are less likely to contain air conditioning units to cope with high heat events. In urban areas, low-income residents are more likely to occupy older homes and apartment complexes with unreinforced masonry, which is particularly susceptible to seismic damage.

Low-income households and communities face disproportionate financial burden from costs associated with disaster preparedness, response, and recovery. Disasters create unexpected expenses which may serve as “tipping points” for families and individuals living on the edge of poverty or homelessness. Recovery costs may be higher for those without resources to conduct hazard mitigation activities ahead of time. Families and individuals who lack access to transportation may be unable to evacuate ahead of an emergency. (Krause & Reeves, 2017)
Low-income residents and renters are also less likely to purchase insurance, meaning that those with the most to lose during an event are also the least prepared to deal with potential losses. Major hurricane events in recent history such as Harvey, Irma, and Katrina all demonstrate that low-income or historically marginalized communities face increased vulnerability to hazard events and struggle the most to recover.

Median household income in the City of St. Helena was approximately $135,781, with an overall poverty rate of around 6%. By comparison, median income and poverty rates for Napa County were nearly $106,000 and 8%, respectively; refer to Table 4-2. Median income and poverty rates are also shown on the block group level in Figure 4-2 and Figure 4-3.

Table 4-2: City of St. Helena Income and Poverty
Area Median Income Poverty Rate
Napa County $105,809 7.9%
City of Napa $100,273 8.1%
City of American Canyon $122,694 7.4%
City of Calistoga $96,667 5.4%
City of St. Helena $135,781 5.7%
Town of Yountville $75,134 10.6%
Source: ACS 5-Year, 2017-2022
Renters are also more vulnerable to natural hazards, as they are less likely to take out property insurance and the decision to make major structural improvements typically lies with the property owner. Federal disaster recovery services can exacerbate inequality between renters and homeowners; payout amounts are significantly higher for homeowners applying through FEMA’s Individual Assistance (IA) program; from 1999 to 2013 U.S. homeowners saw their wealth increase with local hazard damages, whereas renters’ wealth decreased. (Howell, Junia; Elliot, James, 2019)
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Approximately 44% of occupied housing units in the City of St. Helena are renters, compared to approximately 35% for Napa County as a whole; refer to Table 4-3.

Table 4-3: City of St. Helena Renter- and Owner-Occupied Housing Jurisdiction # Occupied
Housing Units
# Renter
Occupied % Renter Occupied # Owner Occupied
% Owner
Occupied
Napa County 49,738 17,676 35.5% 32,062 64.5%
City of Napa 26,978 10,616 39.4% 16,362 60.6%
City of American Canyon 6,192 1,371 22.1% 4,821 77.9%
City of Calistoga 2,042 822 40.3% 1,220 59.7%
City of St. Helena 2,380 1,048 44% 1,332 56.0%
Town of Yountville 1,050 362 34.5% 688 65.5%
Source: ACS 5-Year, 2017-2022
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Figure 4-2: City of St. Helena Median Household Income Map CAL OES SUBMITTAL - JUNE 2026
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Figure 4-3: City of St. Helena Poverty Status Map
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Figure 4-4: City of St. Helena Housing Occupancy Map
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Dependent & Disabled Populations
Age is a significant factor in assessing vulnerability to natural hazards. Both older adults and children are considered dependent populations due to their reliance on caregivers for safety, mobility, and support during emergency events. These populations face heightened risks during disasters such as floods, wildfires, and earthquakes, particularly when compounding factors such as poverty, disability, or social isolation are present.

In the City of St. Helena, approximately 39% of households include at least one individual over the age of 65, and 10% of all households consist of seniors living alone. While only around 1% of senior households live below the poverty line (Table 4-4), seniors, particularly those who are low-income or socially isolated, remain among the most vulnerable populations in disaster situations. Challenges for older adults may include limited mobility, chronic health conditions, reduced digital literacy, and lack of access to real-time emergency alerts. Seniors living alone may require additional assistance during evacuations or power outages, and assisted living facilities necessitate advanced coordination to ensure continuity of care and safety during emergencies.

Children represent another dependent population requiring special consideration (Table 4-5). In St. Helena, nearly 21% of households include individuals under the age of 18, with around 6% of these households headed by a single caregiver. During emergencies, children are entirely dependent on caregivers for decisionmaking, transportation, and access to essential resources. Disruptions to schools, childcare, and youth services can result in significant emotional, educational, and developmental impacts. Families with limited means or single caregivers may also face greater challenges in securing housing, supplies, and recovery assistance.

Figure 4-5 highlights areas within St. Helena with higher concentrations of economically dependent age groups, informing targeted outreach and response strategies during emergencies.

Table 4-4: City of St. Helena Households with Seniors
Jurisdiction Households (HH) 65+ % 65+ Alone %
65+
Poverty %
Napa County 55,588 18,777 33.8% 4,816 8.7% 1,271 2.3%
City of American Canyon 5,924 1,772 29.9% 184 3.1% 111 1.9% City of Calistoga 2,330 1,003 43.0% 419 18.0% 101 4.3%
City of Napa 31,666 10,299 32.5% 2,674 8.4% 703 2.2%
City of St. Helena 2,963 1,153 38.9% 296 10.0% 42 1.4%
Town of Yountville 1,824 873 47.9% 351 19.2% 77 4.2%
Source: ACS 5-Year, 2017-2022
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Table 4-5: City of St. Helena Households with Children
Jurisdiction Households <18 %
<18 Single
Caregiver %
Napa County 55,588 14,596 26.3% 3,109 5.6%
City of American Canyon 5,924 2,633 44.4% 417 7.0%
City of Calistoga 2,330 471 20.2% 33 1.4%
City of Napa 31,666 8,934 28.2% 2,315 7.3%
City of St. Helena 2,963 619 20.9% 168 5.7%
Town of Yountville 1,824 160 8.8% 0 0.0%
Source: ACS 5-Year, 2017-2022
Elderly populations face increased risks during disaster events due to age-related health conditions, mobility limitations, and potential social isolation. In St. Helena, approximately 13% of the noninstitutionalized population lives with a disability, a slightly higher rate than the countywide average of 12% (Table 4-6).

Among those with access and functional needs, elderly individuals with disabilities represent a highly vulnerable subpopulation when it comes to disaster preparedness, response, and recovery. This group includes seniors living with physical or cognitive impairments such as hearing or vision loss, reduced mobility, reliance on assistive medical devices, neurodivergence, or chronic health conditions that may be exacerbated by hazard events (e.g., exposure to wildfire smoke or extreme heat).

Figure 4-6 illustrates that in some portions of the city, more than 47% of the elderly population is estimated to have one or more disabilities, while other areas show lower proportions or lack available data. The spatial distribution shown on this map suggests that vulnerability is not uniform across the city and that certain neighborhoods may have greater needs for evacuation assistance, medical support, and continuity of care during emergencies. Seniors with disabilities may also be more sensitive to extended power outages, disruptions to medical services, and transportation interruptions. These risks are expected to increase under climate change conditions that intensify extreme heat events and strain emergency response resources.

The combination of advanced age and disability can present significant challenges not only during emergency response but also in implementing hazard mitigation measures. Elderly individuals with disabilities may face physical, financial, or logistical barriers to undertaking activities such as seismic retrofitting, anchoring fuel tanks, installing foundation bracing, or implementing residential flood-proofing techniques. Many live in older housing stock that is more vulnerable to earthquake damage or repetitive flooding and may lack the resources or support networks needed to complete mitigation upgrades.

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Table 4-6: City of St. Helena Population with Disabilities and Access to Transportation Jurisdiction Population
Persons
w/
Disability %
Persons
Reliant on
Public
Trans. % Households
HH w/o
Vehicle %
Napa County 137,384 16,544 12.0% 890 0.6% 55,588 2,421 4.4% City of American Canyon 21,669 2,201 10.2% 287 1.3% 5,924 138 2.3% City of Calistoga 5,191 573 11.0% 36 0.7% 2,330 83 3.6% City of Napa 79,233 9,837 12.4% 291 0.4% 31,666 1,554 4.9% City of St. Helena 5,426 683 12.6% 121 2.2% 2,963 219 7.4% Town of Yountville 3,397 683 20.1% 15 0.4% 1,824 210 11.5% Source: ACS 5-Year, 2017-2022
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Figure 4-5: City of St. Helena Dependent Age Groups Map CAL OES SUBMITTAL - JUNE 2026
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Figure 4-6: City of St. Helena Disabled Elderly Map
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Race, Ethnicity & Language
Natural disasters compound racial disparities; non-white individuals and communities receive less recovery aid from FEMA than their white counterparts, even where the amount of damage is the same. (Howell, Junia; Elliott, James R., 2019) (National Advisory Council, 2020) These disparities are evidence of the complicated relationship between disaster recovery and overlapping social vulnerabilities including race, income, language, and health. Black and Latino residents are more likely to be low income and renters, conditions which create barriers to navigating FEMA’s Individual Assistance programs. Communities with more non-white residents may have lower tax revenue and property values, which means less investment in mitigation and rebuilding efforts before and after an emergency.

Figure 4-7 depicts the racial and ethnic composition of the City of St. Helena. According to ACS data, the city is mostly White, but also has a significant Hispanic or Latino population.

Residents with limited English proficiency (LEP) face heightened barriers to understanding emergency alerts, accessing preparedness resources, and navigating post-disaster recovery programs. In St. Helena, approximately 12% of households speak Spanish, but only around 3% report limited English proficiency. (Table 4-7). Figure 4-8 highlights where Spanish-speaking populations are concentrated in St. Helena.

Table 4-7: City of St. Helena Household Languages
Jurisdiction Households (HH) Spanish Speaking %
Limited
English %
Other
Lang. %
Napa County 55,588 8,738 15.7% 2,141 3.9% 12 0.0%
City of American Canyon 5,924 1,069 18.0% 177 3.0% - 0.0% City of Calistoga 2,330 474 20.3% 63 2.7% - 0.0%
City of Napa 31,666 5,800 18.3% 1,653 5.2% 9 0.0%
City of St. Helena 2,963 370 12.5% 88 3.0% - 0.0%
Town of Yountville 1,824 49 2.7% 21 1.2% - 0.0%
Source: ACS 5-Year, 2017-2022
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Figure 4-7: City of St. Helena Race and Ethnicity Map
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Figure 4-8: City of St. Helena Spanish-Speaking Households Map CAL OES SUBMITTAL - JUNE 2026
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Social Vulnerability Index (SVI)
The Centers for Disease Control and Prevention (CDC) Social Vulnerability Index (SVI) for City of St. Helena reveals important spatial and demographic patterns that have direct implications for equitable hazard mitigation planning. As discussed in detail in Volume 1, Section 1.4.3.6, the SVI is a composite measure developed by the CDC to identify communities that are more likely to require support before, during, and after a disaster. It incorporates a range of factors across four key dimensions: socioeconomic status, household composition and disability, minority status and language, and housing type and transportation access. The resulting index score ranges from 0 (lowest vulnerability) to 1 (highest vulnerability).

Figure 4-9 shows that social vulnerability ranges between 0.50 and 1.00 in St. Helena, which is indicative of moderate to high SVI. Areas with higher SVI values indicate neighborhoods where residents may have reduced capacity to prepare for, respond to, and recover from hazard events due to factors such as lower income, higher proportions of renters, limited access to vehicles, language barriers, or greater concentrations of elderly and disabled individuals. Conversely, areas with lower SVI scores generally reflect populations with greater access to resources and adaptive capacity.

Spatial patterns in the SVI map suggest that higher social vulnerability is concentrated in portions of the central and southern areas of the city, where multiple vulnerability indicators overlap. These areas may experience disproportionate impacts during events such as flooding, extreme heat, earthquakes, or wildfire smoke episodes, particularly if hazards coincide with power outages, transportation disruptions, or prolonged recovery periods. Residents in higher-SVI neighborhoods may also face challenges accessing emergency information, evacuation assistance, sheltering, and post-disaster financial or housing resources.

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Figure 4-9: City of St. Helena CDC Social Vulnerability Index Map CAL OES SUBMITTAL - JUNE 2026
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4.2.3 Economy
The City of St. Helena plays an important economic role within central Napa County, serving as a local employment center and tourism hub. St. Helena serves as a commercial and business center for the surrounding towns and unincorporated areas, including Calistoga, Angwin, Deer Park, Rutherford, and the unincorporated area south of St. Helena. The local economy is largely centered around visitor-serving commercial uses and wine production. St. Helena is also home to or located near three higher educational institutions: the Culinary Institute of America, Napa Valley College Upper Valley Campus, and Pacific Union College in Angwin.

Retail, restaurants, and visitor-serving commercial uses are primarily concentrated on Main Street (Highway 29). These businesses contribute significantly to local tax revenues and provide jobs for residents of St. Helena and surrounding communities. At the same time, the concentration of economic activity along Main Street increases the importance of protecting critical infrastructure, transportation corridors, and utility systems from natural hazards such as flooding, earthquakes, and power outages.

The city’s commercial economy includes neighborhood-serving retail, restaurants, and personal services that support daily needs and contribute to community vitality. These businesses are particularly sensitive to hazard-related disruptions, as temporary closures, infrastructure damage, or reduced access can result in lost income and longer-term economic impacts. Small businesses may have limited capacity to absorb prolonged disruptions, making economic resilience an important consideration in hazard mitigation planning.

A significant portion of St. Helena’s workforce is employed in sectors that involve physical labor or outdoor activity, including agriculture and visitor-serving commercial uses. These workers may face heightened exposure to hazards such as extreme heat, wildfire smoke, and poor air quality. Climate change projections indicating more frequent heat events and longer wildfire seasons have implications for worker safety, productivity, and business continuity within these sectors.

Economic vulnerability is also influenced by income variability and employment stability. Workers in hourly or service-based positions may experience immediate income loss during disaster-related closures or evacuations, which can compound household vulnerability and slow community recovery. Protecting employment centers, maintaining transportation access, and ensuring continuity of utilities and communications are therefore key components of reducing economic disruption from hazard events.

4.2.4 Growth Trends & Future Development
The City of St. Helena has experienced moderate growth since the 1970s, with development patterns shaped by adopted growth management policies, infrastructure capacity, and regional housing demand. Growth in recent decades has occurred primarily through planned residential development and visitor-serving commercial uses. This approach reflects the city’s long-standing emphasis on directing growth toward areas that can be efficiently served by public services and infrastructure while limiting outward expansion into agricultural and environmentally sensitive lands.

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Residential growth has been driven largely by approved specific plans and infill development within existing neighborhoods. Recent development activity has included a mix of single-family and multi-family housing intended to accommodate population growth and meet state-mandated housing requirements. The City’s Housing Element and Annual Progress Reports document continued efforts to increase housing supply while addressing affordability, infrastructure demands, and community character.

Future development in St. Helena is expected to continue focusing on buildout of remaining developable parcels within the Urban Limit Line and Sphere of Influence. Planned growth areas are generally located near existing transportation corridors, utilities, and employment centers, supporting more compact and efficient development patterns. This strategy reduces the need for extensive new infrastructure and helps limit exposure to hazards associated with hillside development, wildfire risk, and access constraints.

Economic development is also anticipated to remain a key component of future growth. Expansion and intensification of industrial and commercial uses, particularly those related to logistics, manufacturing, and the wine industry, are expected to support employment and fiscal stability. At the same time, continued development in flood prone areas and near critical transportation routes underscores the importance of incorporating hazard mitigation and climate adaptation measures into future land use and infrastructure planning.

4.3 Planning Process
The City of St. Helena followed the planning process detailed in Volume 1, Section 2, including participating in the county-wide Hazard Mitigation Planning Team (HMPT) and formulating their own internal planning team to support the broader planning process.

The city’s representatives in the Steering Group led stakeholder and public engagement efforts alongside the Consultant Team, with assistance from the county-wide HMPT and their internal planning team. This engagement process is described in Volume 1. Specifically, for the City of St. Helena, this included postings to the city website and social media, and outreach events, as documented in Appendix B. Examples of Key Stakeholders engaged by Napa County on behalf of the city with relevance to the development of St. Helena’s mitigation strategy include the USDA and other federal agencies; CAL FIRE and other state agencies; other neighboring jurisdictions; community-based organizations such as the Chamber of Commerce; utility providers like PG&E; UC Davis and other academia; and local businesses.

All Key Stakeholders that were invited to participate in the planning process are listed in Volume 1, Section 2, and the input received from stakeholders was integrated into the city’s annex, as described in Volume 1 Table 2-9. The city’s internal planning team participants, their positions, and how they participated in the planning process are shown in Table 4-8.

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Table 4-8: City of St. Helena Planning Team and Steering Group Members Team Members Title Description of Involvement
Anil Comelo City Manager (former) Lead Point-of-Contact, HMPT #1 and #2 John Sorensen Fire Chief Alternate Point-of-Contact, HMPT #1, #2, #3 and #4, BO #1 and #2
Andrew Bradley Program Manager Participating Stakeholder, BO #1 and #2 Chris Hartley Police Chief (former) Participating Stakeholder, BO #1 Dave Jahns Parks and Recreation Director
(former) Participating Stakeholder, BO #1 and #2
Jackie Oneal Senior Planner Participating Stakeholder, BO #1 and #2 Leza Mikhail Director of Community
Development Participating Stakeholder
Maya DeRosa
Planning and Building
Director (former) Participating Stakeholder, BO #1
Joseph Leach Public Works Director / City
Engineer Participating Stakeholder, BO #1 and #2
Justin Tharp Police Lieutenant Participating Stakeholder, BO #1 Lesley Milton Deputy City Manager (former) Participating Stakeholder, BO #1 and #2 Mandy Kellogg
Administrative Services
Director Participating Stakeholder, BO #1 and #2
Phillip Henry Chief Building Official Participating Stakeholder, BO #1 and #2 City of St. Helena participated in a comprehensive hazard mitigation planning process as part of the 2026 Napa County MJHMP update. This included a series of breakout meetings, listed in Table 4-9 that engaged the district’s planning team, which included key city personnel and stakeholders in evaluating hazards, identifying local vulnerabilities, and prioritizing mitigation strategies.

The process began with a County-Wide Steering Group Kickoff Meeting on February 28, 2024. This initial meeting focused on welcoming participants, establishing a shared understanding of the project scope and schedule, clarifying roles and responsibilities of the Steering Group, the county-wide Hazard Mitigation Planning Team (HMPT), and individual jurisdictional planning teams, and included a review of key changes since the 2020 Local Hazard Mitigation Plan The meeting set the foundation for coordinated participation throughout the planning effort.

Throughout the series of breakout meetings, the City of St. Helena engaged in a structured and collaborative planning process focused on assessing hazard risks, identifying vulnerabilities, and developing targeted mitigation strategies. The meetings began with recaps of the county-wide HMPT meetings to ensure alignment of goals and progress.

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During the September 24, 2024, breakout out meeting, discussions concentrated on community engagement outcomes, initial risk assessments, and the integration of demographic data to better understand vulnerable populations. Jurisdictional teams reviewed their specific hazard exposures using the Risk Assessment Mapping Platform (RAMP) and participated in prioritization exercises to identify their top hazards.

The June 18, 2025, breakout meeting shifted toward reviewing local capabilities and defining specific areas of concern, which informed the drafting of problem statements. Teams worked collaboratively to refine mitigation alternatives, align actions with FEMA guidelines, and develop a shortlist of priority mitigation actions and inter-jurisdictional collaboration opportunities. Participants also engaged in a hexagon mapping activity designed to visually identify mitigation actions that could benefit from or require interjurisdictional coordination. These collaborative efforts helped shape a refined set of mitigation alternatives, establish shared planning goals, and align local strategies with FEMA’s Hazard Mitigation Assistance (HMA) funding framework. The meetings also included consensus-building activities around hazard rankings, capabilities, and planned actions, while providing regular updates on the overall project schedule.

Table 4-9: City of St. Helena Planning Team Meetings
Meeting & Date Agenda / Topics Goals / Key Inputs
County-Wide Steering Group and HMPT Kick-off and Meetings #1 & #2 February 28, 2024– July 18, 2024
St. Helena Planning
Team
Breakout Meeting #1
September 24, 2024
▪ County-wide HMPT meetings #1 and #2 recaps
▪ Community engagement progress and results
▪ Risk assessment and community vulnerability
▪ Demographics and vulnerable populations
▪ Overview of jurisdiction-specific hazard risks and
exposure
▪ Introduction to Risk Assessment Mapping Platform
(RAMP)
▪ Jurisdiction-specific hazard risk ranking exercise
▪ Project schedule updates and next steps
▪ Consensus on jurisdictionspecific priority hazards
▪ Identify capabilities and
potential mitigation actions
▪ Community engagement
volunteers
County-Wide HMPT Meeting #3
March 25, 2025
St. Helena Planning
Team
Breakout Meeting #2
June 18, 2025
▪ Breakout Meeting #1 and HMPT #3 recaps
▪ Review capabilities assessment
▪ Review areas of concern and define problem
statements
▪ Principles of effective mitigation strategies and
actions, and mitigation alternatives
▪ Refine and align jurisdiction-specific mitigation
actions exercise
▪ Project schedule updates and next steps
▪ Consensus on jurisdictionspecific capabilities
▪ Consensus on jurisdictionspecific areas of concern
▪ Consensus on priority
mitigation actions and
collaboration opportunities
▪ Community engagement
volunteers
County-Wide HMPT Meeting #4
December 10, 2025
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4.3.1 Public Input & Draft Review
As detailed in Volume 1, Section 2, the draft plan was available for public review and comment from May 15 to June 2, 2026. Public comments received during that time were similar to those gathered throughout the public engagement process, including the need for more equity in the distribution of mitigation activities and funding and the need for enhanced cooperation among jurisdictions, utility providers, and state agencies. More specifically for St. Helena, public feedback received requested additional information and clarity about the risk assessment as well as updates to city plans and policies, such as the General Plan Safety Element, to better integrate equitable hazard mitigation. These comments were incorporated into the city’s mitigation strategy, as appropriate; although, most were already addressed by the Mitigation Action Plan which was based on previous public input. Integration of this MJHMP and municipal annex with the General Plan, Municipal Code, and other city plans and policies will occur throughout the next five-year implementation period, as described in Volume 1, Section 2, and Section 4.6.1.

Public and stakeholder input was gathered and incorporated throughout the plan development process, before the public review period, such as from the online public survey (see Volume 1, Section 2.1.2 and Appendix B, for details). During the review period, jurisdictional staff and stakeholders that participated in the plan development also reviewed the public draft and provided comments on minor corrections and revisions, which were addressed in the final plan.

4.4 What’s New
This section provides an overview of hazard mitigation planning efforts for the planning area and highlights the updates made in the 2026 MJHMP. The City of St. Helena previously participated and maintained a Hazard Mitigation Plan, which guided resilience planning and hazard mitigation actions at the city level. St.

Helena is updating their current plan on a county wide level. This integration reflects the city’s ongoing commitment to regional resilience and acknowledges that many hazards such as flooding, severe storms and earthquakes cross jurisdictional boundaries.

Through participation in the MJHMP, St. Helena has identified its highest priority hazards, developed hazard specific problem statements, and proposed actionable strategies to reduce risks. By aligning with countywide partners and leveraging regional resources, St. Helena has strengthened its capacity to prepare for, withstand, and recover from disasters while continuing to protect its unique community character.

4.4.1 Mitigation Activities
The city has successfully implemented several initiatives aimed at addressing identified vulnerabilities.

Some of these accomplishments are highlighted in this section and have directly contributed to reducing risks from hazards such as flooding, all hazards, and severe weather. These completed projects showcase St. Helena’s ability to effectively plan, fund, and execute measures that protect its residents and infrastructure.

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In addition, St. Helena has systematically reviewed and adjusted its mitigation actions, exemplifying adherence to FEMA’s Planning Policy Guide principles and emphasizing the importance of dynamic and adaptive mitigation planning. By fostering partnerships, leveraging funding opportunities, and prioritizing equity in implementation, the city aligns with best practices to build resilience against natural disasters.

This ongoing effort is a testament to the city's commitment to the principles of risk-informed decisionmaking, equitable resource allocation, and integration with broader regional and state hazard mitigation objectives.

Adjustments to Previous Mitigation Actions
A significant portion of the city's mitigation efforts remain ongoing or in the pipeline. These actions, ranging from infrastructure upgrades to community outreach initiatives, represent the city’s proactive approach to addressing hazards as resources become available.

Recognizing constraints such as limited funding, staffing, and shifting priorities, the city has reevaluated certain initiatives, leading to their reprioritization or canceling of mitigation actions. Factors such as feasibility, cost-effectiveness, and emerging risks informed these decisions, ensuring alignment with the city’s updated hazard mitigation goals. Adjustments to previous mitigation actions are documented as part of the City of St. Helena’s Mitigation Action Plan Table 4-17, and more specific status updates are provided in Table 4-18.

4.4.2 Mitigation Successes
Since the adoption of the 2021 Hazard Mitigation Plan, the City of St. Helena has made measurable progress in implementing mitigation actions that reduce risk and enhance community resilience. These successes reflect the City’s continued commitment to integrating hazard mitigation into local planning, capital improvement projects, and community programs.

The following success stories highlight completed and ongoing efforts that address key hazards such as drought, climate change, and resource sustainability. Collectively, these initiatives demonstrate the City’s ability to move from planning to implementation by leveraging regulatory tools, aligning with state requirements, and advancing projects that provide long-term risk reduction benefits to the community.

Water Conservation & Drought Resilience through Landscape Standards (WELO) The City of St. Helena has implemented water-efficient landscape requirements through adoption of the State of California’s Water Efficient Landscape Ordinance (WELO) into its local zoning and development code, ensuring that new development and significant landscape renovations incorporate long-term water conservation measures. This regulatory approach supports drought resilience and sustainable water use by requiring efficient irrigation systems, climate-appropriate plant selection, and limits on high-water-use landscaping.

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Under WELO, new development projects are required to prepare landscape documentation that demonstrates compliance with water budgets, including maximum applied water allowance (MAWA) calculations and efficient irrigation design. These requirements promote the use of drought-tolerant and native vegetation, reduce reliance on potable water for irrigation, and improve overall landscape performance during periods of water scarcity.

The ordinance serves as a proactive mitigation measure by reducing community-wide water demand and increasing resilience to drought conditions, which are expected to intensify due to climate change. By integrating water efficiency standards into the development review process, the City ensures that future growth does not exacerbate water supply constraints and that landscapes remain sustainable under increasingly variable hydrologic conditions.

In addition to water savings, WELO-compliant landscapes provide co-benefits such as improved soil health, reduced runoff, and enhanced urban aesthetics. The program represents a cost-effective, regulatory-based mitigation strategy that aligns with state water conservation goals while supporting long-term community resilience.

Updated Safety Element
The Safety Element update includes multiple mitigation-forward policies such as tailored evacuation messaging for single-access neighborhoods, assessing ingress/egress improvements, zone-based evacuation planning, siting critical infrastructure outside hazard zones where feasible, and maintaining participation in the Napa County MJHMP update cycle.

4.5 Risk Assessment
This section focuses on profiling hazards specific to the City of St. Helena and assessing their vulnerability independent of the broader county-wide planning area, which has been evaluated in Section 3 of Volume 1.

The hazard profiles in Volume 1 discuss overall impacts to the planning area and describe relevant plans, policies, and regulations; past events; location; frequency and probability of future occurrences; severity and extent; warning time; secondary hazards; and climate change impacts. For more information on risk assessment methodologies, see Volume 1, Appendix A.

This section includes a tailored vulnerability assessment, analyzing assets at risk such as population, property, and critical facilities and infrastructure unique to the city, and information on city-specific differences in hazard vulnerability across the planning area. It also identifies total city assets at risk, including people, property, and critical facilities and infrastructure within the city. In addition, this section presents growth and development trends for the community, offering insights into vulnerabilities and risks that represent the broader context of assets at risk.

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4.5.1 Hazard Screening & Prioritization
Members of the Planning Team from each participating jurisdiction came together to collaboratively decide which county-wide hazards would be included in the MJHMP, and which would be excluded. Hazard screening and prioritization took place early in the process and integrated historic data, local knowledge, and consensus opinions to create a risk assessment matrix for the county as well as for each participating jurisdiction. These matrices indicate the priority of hazards prior to further refinement. Details about this process, the results of the discussion, and in-depth profiles for county-wide hazards can be found in Volume 1, Sections 2 and 3.

The City of St. Helena’s internal planning group used the same hazard identification and prioritization process as the county-wide Planning Team. They reviewed previously prepared hazard mitigation plans and other relevant documents to determine the realm of natural hazards that have the potential to affect the city. Table 4-10 provides a crosswalk of hazards identified in select planning documents, including the 2020 Napa County MJHMP, the City of City of St. Helena General Plan, and the 2023 State of California HMP.

The crosswalk was used to develop a preliminary hazards list, providing a framework for the group to evaluate which hazards were truly relevant to the City of St. Helena and which ones were not.

The internal planning group then ranked hazards based on their probability of affecting the City of St.

Helena and potential impacts on the community. Figure 4-10 displays the results of the hazard risk ranking exercise that was performed before further refinement. All hazards have been profiled in Volume 1 of this document. The purpose of this annex is to specifically address the city’s vulnerability to specifically identified hazards.

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Table 4-10: City of St. Helena Document Review of Potential Hazards Hazard 2020 Napa County
MJHMP
City of St. Helena General
Plan
2023 California
SHMP
Agricultural Pests ■ ■
Avalanche ■
Climate Change ■ ■ ■
Coastal ■
Dam Failure ■ ■
Drought ■ ■ ■
Earthquake / Liquefaction ■ ■ ■
Extreme Cold ■
Extreme Heat ■ ■
Extreme Weather / Storms ■ ■ ■
Flood ■ ■ ■
Geologic / Mass Movement ■ ■ ■
Human-Caused ■
Insects ■
Levee Failure ■
Pandemic Disease ■ ■
Sea Level Rise ■
Soil ■
Subsidence ■
Tornado ■
Tsunami / Seiche Wave ■
Volcano ■
Wildfire ■ ■ ■
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Figure 4-10: City of St. Helena Risk Assessment Matrix
Note: Hazard naming in the Risk Assessment Matrix may not match the final naming used. Refer to hazards prioritization summary table.

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Priority Hazards
The results of the initial risk ranking exercise completed by the city’s Planning Team, before further refinement, are identified in the county’s completed matrix in Figure 4-10. Table 4-11 provides the final list of priority hazards and subhazards with additional details about why certain hazards were chosen and why others were not prioritized. However, it should be noted that many hazards not prioritized for profiling are briefly discussed as secondary or compounding hazards, and subhazards that were profiled and included in the risk assessment are listed specifically.

Table 4-11: City of St. Helena Hazards Prioritization Summary Hazard Priority Explanation
Earthquake / Liquefaction High Profiled in Volume 1, Section 3.3.4, and Section 4.5.2.2 in this annex, including Liquefaction
Wildfire Extreme Profiled in Volume 1, Section 3.3.1, and Section 4.5.2.1 in this annex Flood High Profiled in Volume 1, Section 3.3.2, and Section 4.5.2.3 in this annex Levee Failure -
Profiled in Volume 1, Section 3.3.2; not a priority due to low probability and impact potential
Extreme Weather / Storms High
Profiled in Volume 1, Section 3.3.5, and Section 4.5.2.7 in this annex as Severe Weather, including High Wind and Heavy Rain (Winter Weather not a priority due to low probability and impact potential) Drought High Profiled in Volume 1, Section 3.3.6, and Section 4.5.2.5 in this annex Geologic / Mass Movement Medium Profiled in Volume 1, Section 3.3.5, and Section 4.5.2.4 in this annex as Slope Failure
Extreme Heat High Profiled in Volume 1, Section 3.3.8, and Section 4.5.2.8 in this annex Agricultural Pests -
Profiled in Volume 1, Section 3.3.9; not a priority due to low probability and impact potential and jurisdictional focus
Sea Level Rise - Profiled in Volume 1, Section 3.3.9; not a priority due to no exposure Climate Change High Profiled in Volume 1, Section 3.3.9, and Section 4.5.2.8 in this annex and discussed as a compounding hazard in relevant profiles
Dam Failure High Profiled in Volume 1, Section 3.3.3, and Section 4.5.2.6 in this annex CAL OES SUBMITTAL - JUNE 2026
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4.5.2 Vulnerability to Specific Hazards
Assessing vulnerabilities exposes the unique characteristics of individual hazards and begins the process of narrowing down which areas within the city are vulnerable to specific hazard events. The vulnerability assessment considered unique local knowledge of hazards and impacts and a GIS overlaying method for examining such vulnerabilities in more depth. Using these methods, the city’s planning group estimated vulnerable populations, properties, and assets, and potential losses. In addition, the exposure of city assets to drought, geological, earthquake, wildfire and flood hazards were also considered.

Many of the hazard profiles include a snapshot map and damage estimation tables that illustrate the city’s vulnerabilities to those specific hazards. These maps assisted the planning group in understanding the hazard exposure of populations, parcels, and critical facilities and infrastructure. Each snapshot map contains an exposure summary that displays the percentage of the population, the improvement and content value of parcels, and the amount of critical infrastructure that is exposed. For hazards without geospatial extents, such as drought and severe weather, narratives are provided instead of exposure maps and tables.

Based on the hazard prioritization exercise, this vulnerability assessment focuses on nine hazards for the City of St. Helena, some of which encompass sub hazards such as Liquefaction and Heavy Rain Wildfire
SECTION 4.5.2.1
Earthquake
SECTION 4.5.2.2
Flood
SECTION 4.5.2.3
Slope Failure
SECTION 4.5.2.4
Drought
SECTION 4.5.2.5
Dam Failure
SECTION 4.5.2.6
Severe Weather
SECTION 4.5.2.7
Extreme Heat
SECTION 4.5.2.8
Climate Change
SECTION 4.5.2.9
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Wildfire Hazard
Wildfire risk in the City of St. Helena is primarily concentrated along the eastern and western edges of the community, where developed areas interface with open space, and the Mayacamas Mountains and Howell Mountains. The wildfire risk exposure map, Figure 4-11, shows that portions of the city and surrounding Sphere of Influence are located within Moderate and High Fire Hazard Severity Zones, particularly in areas adjacent to undeveloped land and wildland vegetation.

The eastern boundary of St. Helena, which transitions from the Napa Valley floor to the Howell Mountains near Silverado Trail, is characterized by Very High wildfire hazard. These areas contain dense vegetation on steep slopes that can dry rapidly during summer and fall months, increasing the potential for fastmoving fires under windy or extreme heat conditions. Residential neighborhoods, resorts, and wineries located near this wildland–urban interface (WUI) may face heightened risk related to ember intrusion, evacuation constraints, and access limitations during wildfire events.

High wildfire hazard areas are also present along portions of the City’s western edge near the Mayacamas Mountains. Seasonal drying of vegetation and wind conditions can exacerbate localized wildfire risk, particularly during extended drought periods.

The exposure summary associated with the wildfire risk map indicates that, within current mapped hazard areas, there are no permanent residential populations, parcels, or critical infrastructure classified within the Very High Fire Hazard Severity Zone inside city limits. As a result, population exposure, parcel exposure, and critical infrastructure exposure rates within the highest hazard category are reported at 186 persons and 13 parcels. This reflects St. Helena’s relatively urbanized development pattern and limited extent of very high-risk wildfire terrain within incorporated boundaries.

Despite the small amount of Very High Fire Hazard Severity Zones within the city, wildfire remains an important planning consideration due to proximity to higher-risk areas outside city limits, regional wildfire activity, and secondary impacts such as smoke exposure, power shutoffs, transportation disruptions, and evacuation demands. Climate change projections indicating hotter temperatures, longer dry seasons, and increased frequency of extreme weather events are expected to exacerbate wildfire conditions throughout Napa County, including areas surrounding St. Helena.

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Figure 4-11: Exposure Summary – City of St. Helena Wildfire Risk CAL OES SUBMITTAL - JUNE 2026
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Earthquake Hazard
The City of St. Helena is subject to significant earthquake risk due to its location within the seismically active San Francisco Bay Area and proximity to multiple active faults in Napa County and the surrounding region. Earthquake impacts in the city are best illustrated through scenario modeling, including the Hunting Creek–Berryessa Earthquake Scenario (Magnitude 7.1) and the West Napa Earthquake Scenario (Magnitude

6.7). These scenarios reflect credible seismic events that could produce strong to severe ground shaking throughout the city.

Under the Hunting Creek–Berryessa M7.1 scenario (Figure 4-12), ground shaking across St. Helena is generally characterized as Strong and Very Strong (Modified Mercalli Intensity [MMI] VI – VII). Exposure summaries indicate that approximately 300 residents, 7 parcels, and nearly $19 million in building improvement value and $7 million in content value fall within these intensity ranges. In addition, all mapped critical infrastructure categories, including essential facilities, hazardous materials sites, high potential loss facilities, and transportation and lifeline systems, are exposed to damaging levels of ground shaking.

The West Napa Earthquake M6.7 scenario, Figure 4-13, represents a less impactful event for St. Helena. Under this scenario, 100 percent of the City’s population, parcels, and assessed parcel value are exposed to Strong (MMI VI). Exposure summaries indicate that approximately 200 residents, 200 parcels, and nearly $110 million in building improvement value and $84 million in content value fall within these intensity ranges.

While exposure summaries indicate no population, parcels, or critical infrastructure located in the highest modeled intensity categories for this scenario within city limits, the widespread nature of strong shaking suggests the potential for damage to buildings, infrastructure, and lifelines, particularly older structures and non-ductile construction.

Earthquake impacts associated with these scenarios include structural damage to residential, commercial, and industrial buildings; failure of non-structural components; disruption of transportation corridors such as Highway 29 and Silverado Trail; and damage to utilities including water, wastewater, power, and communications systems.

Secondary earthquake hazards also present a concern for St. Helena. These include hazardous materials releases from industrial and commercial facilities, fires following earthquakes, prolonged power outages, and limited access for emergency response due to damaged roadways or bridges. Given the city’s strategic location in the upper Napa Valley, such disruptions could have regional economic and public safety consequences.

Liquefaction
Liquefaction represents a significant secondary earthquake hazard for the City of St. Helena due to local soil conditions, groundwater characteristics, and proximity to the Napa River. Liquefaction occurs when saturated, loose, fine-grained soils temporarily lose strength during intense ground shaking, causing the ground to behave more like a liquid. This phenomenon can result in ground settlement, lateral spreading, CAL OES SUBMITTAL - JUNE 2026
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loss of bearing capacity, and damage to buildings, roadways, and buried utilities. While liquefaction is a consideration in hazard mitigation planning, it is not profiled as a standalone hazard but addressed as a secondary earthquake effect.

Areas of St. Helena with higher liquefaction susceptibility are generally located in low-lying portions of the city. These conditions are most prevalent near the Napa River, where shallow groundwater levels increase the likelihood of liquefaction during moderate to strong earthquake shaking (Figure 4-14). In these areas, even structures designed to withstand seismic forces may experience damage if foundations or supporting soils lose stability.

Liquefaction can significantly amplify earthquake impacts by damaging lifeline infrastructure such as water, wastewater, storm drainage, gas, and telecommunications systems. Buried pipelines may rupture or become misaligned, roadways and bridges may settle or deform, and access routes needed for emergency response may be compromised. Industrial and commercial areas located on susceptible soils may face additional risks related to hazardous materials releases if tanks, pipelines, or containment systems are affected.

The earthquake scenario analyses for St. Helena indicate that strong to very strong ground shaking (MMI VII–VIII) is likely under credible seismic events. When combined with local liquefaction-prone soils, these shaking intensities increase the potential for widespread ground failure in susceptible areas. As a result, liquefaction poses a threat not only to individual structures but also to the city’s broader functionality and recovery following a major earthquake.

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Figure 4-12: Exposure Summary – City of St. Helena Earthquake Risk (M7.1 Hunting Creek–Berryessa) CAL OES SUBMITTAL - JUNE 2026
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Figure 4-13: Exposure Summary – City of St. Helena Earthquake Risk (M6.7 West Napa) CAL OES SUBMITTAL - JUNE 2026
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Figure 4-14: Exposure Summary – City of St. Helena Liquefaction Risk CAL OES SUBMITTAL - JUNE 2026
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Flood Hazard
Flooding is a significant natural hazard for the City of St. Helena due to its location on the Napa River.

Portions of the City are subject to riverine flooding, particularly during major precipitation events. Flood hazard areas within St. Helena are primarily concentrated along the Napa River, as well as along localized drainage corridors.

The FEMA Flood Risk Exposure map, Figure 4-16, shows areas within the 100-year (1-percent annual chance) and 500-year (0.2-percent annual chance) floodplains, including mapped floodway areas and zones protected by levees. These flood-prone areas reflect the combined influence of river overflow and constrained drainage capacity. Flood hazards in these areas may be exacerbated during extreme storm events.

Exposure analysis indicates that approximately 725 residents are located within mapped flood hazard areas.

In addition, over 500 parcels are exposed to flooding, with an estimated $166 million in building improvement value. A small number of essential facilities or hazardous materials sites are located within the mapped flood hazard areas and several transportation and lifeline facilities intersect flood-prone zones, highlighting the potential for access disruptions and service interruptions during flood events.

Flooding in St. Helena can result in structural damage to buildings, roadway inundation, utility system impacts, and long-term economic disruption. Repetitive or prolonged flooding may also affect industrial and commercial areas near the river, compounding recovery challenges. Secondary impacts include erosion, sediment deposition, and degradation of wetlands and shoreline infrastructure.

Climate change is expected to increase flood risk in St. Helena over time. Projections for more intense precipitation events may expand flood extents, increase flood depths, and reduce the effectiveness of existing levees and drainage systems. Areas currently mapped within the 500-year floodplain may experience more frequent flooding in the future, increasing exposure to residents, infrastructure, and economic assets.

National Flood Insurance Program
The National Flood Insurance Program (NFIP) makes federally backed flood insurance available to homeowners, renters, and business owners in participating communities. FEMA has prepared a detailed Flood Insurance Study (FIS) for Napa County and municipalities. The study presents water surface elevations for floods of various magnitudes, including the 1% annual chance flood (100-YR flood) and the

0.2% annual chance flood (500-YR flood). Base flood elevations and the boundaries of the 100- and 500-YR floodplains are shown on Flood Insurance Rate Maps (FIRMs), which are the principal tools for identifying the extent and location of the flood hazard. FIRMs are the most detailed and consistent data source available, and for many communities they represent the minimum area of oversight under their floodplain management program. See Section 4 of Volume 1 for general information on the NFIP.

The City of St. Helena has participated in the NFIP since 1980 and has adopted the most recent FIRMs and FIS issued by FEMA (dated September 26, 2008) as well as local floodplain development regulations in CAL OES SUBMITTAL - JUNE 2026
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compliance with the minimum NFIP standards (St. Helena Municipal Code Chapter 15.52). These minimum standards include procedures and provisions for substantial improvements and substantial damages to existing structures, the latter of which are employed by the floodplain administrator and city building inspectors following any hazard event affecting structures located in the flood hazard area in accordance with NFIP requirements. Regulations for substantial improvements are enforced via permitting procedures.

Implementation and enforcement of the city’s floodplain regulations are assigned to the floodplain administrator.

The City of St. Helena is currently in good standing with the provisions of the NFIP. Compliance is monitored by FEMA regional staff and by the California Department of Water Resources under a contract with FEMA.

Maintaining compliance under the NFIP is an important component of flood risk reduction. See Table 4-12 for more information on the City’s policies and historic flood insurance claims.

Table 4-12: City of St. Helena National Flood Insurance Program Information City of St. Helena NFIP Status and Flood Insurance Statistics NFIP Status Participating Since 5/01/1980
Community Identification (CID) 060208
CRS Class (Entry Date) N/A
Policies in Force (Total Coverage) 47 Policies ($18,477,000 Coverage) Policies Inside SFHA / Outside SFHA Inside 26 / 21 Outside Policies in Coastal Zones (Total Coverage) N/A
Total Claims (Total Paid) 51 Claims ($1,789,688 Paid)
Repetitive Loss (RL) / Severe Repetitive Loss (SRL) Properties 12 RL / 0 SRL Repetitive Loss Payments $671,596
Note: The number of policies is by property and does not count policies for individual buildings. The Privacy Act of 1974 (5 USC 522a) restricts the release of certain types of data to the public. Flood insurance policy and claims data is included in the list of restricted information. FEMA can only release such data to state and local governments, and only if the data is used for floodplain management, mitigation, or research purposes. Therefore, this plan does not identify the repetitive loss properties or include claims data for any individual property.

Principal Flooding Sources
The principal flooding source for the City of St. Helena is the Napa River and its tributaries. Riverine flooding from the Napa River and its tributaries is the primary driver of mapped flood risk in St. Helena. During major storm events, high river flows can overtop banks or exceed channel capacity.

Localized flooding from creeks, drainage channels, and stormwater systems occurs within the city but generally represents a secondary source compared to the riverine flooding associated with the Napa River system.

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Figure 4-15: City of St. Helena Flood Risk (FEMA Zones and DWR Awareness Zone) CAL OES SUBMITTAL - JUNE 2026
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Figure 4-16: Exposure Summary – City of St. Helena Flood Risk (FEMA Zones) CAL OES SUBMITTAL - JUNE 2026
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Slope Failure
Slope failure, including landslides, debris flows, and earth movement, poses a localized but notable hazard for the City of St. Helena due to the presence of steep terrain along the western and eastern edges of the city.

The Landslide Risk Exposure map, Figure 4-17, based on data from the California Geological Survey, identifies areas of moderate and high landslide susceptibility. High-susceptibility areas are concentrated outside the City’s urban core, particularly in undeveloped or sparsely developed hillside terrain. These areas are more prone to slope failure during periods of prolonged or intense rainfall, which can saturate soil and reduce slope stability.

Exposure analysis indicates that slope failure risk affects a relatively small portion of St. Helena’s developed areas. Approximately 500 residents and 50 parcels are located within mapped high-susceptibility zones, with an estimated $90 million in building improvement and $60 million in contents value exposed. Only three essential facilities, hazardous materials sites, high potential loss facilities, or major transportation and lifeline infrastructure are located within high-risk slope failure areas, limiting the potential for widespread community impacts.

Although overall exposure is limited, slope failure events can still result in localized damage to structures, roadways, and utilities, particularly where development occurs near steep slopes or drainage channels.

Landslides may also block access routes, disrupt emergency response, and increase sediment loads in downstream waterways. In addition, slope instability can be triggered or exacerbated by earthquake shaking, compounding risks during major seismic events.

Climate change may increase slope failure risk over time by contributing to more intense storm events and longer periods of soil saturation. Hillside areas around St. Helena may experience increased erosion and slope movement under these conditions, emphasizing the importance of proactive planning and monitoring.

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Figure 4-17: Exposure Summary – City of St. Helena Slope Failure Risk CAL OES SUBMITTAL - JUNE 2026
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Drought Hazard
The National Drought Monitor provides drought data and maps nationally and on a localized, watershed scale. The National Drought Monitor is the product of 11 agencies, including the NDMC, NOAA and USDA, and is available at http://droughtmonitor.unl.edu/. The National Drought Monitor categorizes the level of drought from D0 through D4, with D4 being the highest “exceptional drought.” Table 4-13 depicts drought classifications and impacts from the level of drought occurrence in California, while Figure 4-18 shows a time series of the level of drought in Napa County from 2000 to 2025 according to the National Drought Monitor.

Drought is a recurring and long-term hazard for the City of St. Helena due to California’s Mediterranean climate, variable precipitation patterns, and increasing impacts from climate change. Periods of prolonged below-average rainfall, reduced snowpack in the Sierra Nevada, and higher temperatures can significantly affect regional water supplies, ecosystems, and community resilience. Although drought does not typically cause immediate physical damage like other hazards, its cumulative impacts can be widespread and longlasting.

St. Helena relies on a combination of surface water and imported water supplies that are vulnerable to regional drought conditions. Extended drought periods can reduce available water supplies, increase demand during hotter and drier conditions, and place stress on water delivery systems. Drought conditions may also require implementation of mandatory water conservation measures, affecting residents, businesses, landscaping, and industrial operations.

Drought can exacerbate other natural hazards affecting St. Helena. Dry conditions increase vegetation stress and fuel loads, elevating wildfire risk in surrounding grasslands and open space areas. Reduced soil moisture can also contribute to land subsidence, soil instability, and increased erosion during subsequent storm events. In addition, drought can degrade wetlands and riparian habitats along the Napa River and bayfront, reducing their natural flood attenuation and ecological functions.

Economic impacts of drought may include increased operational costs for businesses, reduced agricultural productivity in the surrounding region, and higher household expenses related to water use restrictions or rate adjustments. Vulnerable populations, including low-income households and elderly residents, may be disproportionately affected by higher utility costs and reduced access to cooling and water resources during extreme heat events associated with drought.

Climate change projections indicate that drought conditions in California are likely to become more frequent and severe, with longer dry periods punctuated by fewer but more intense storm events. These trends increase uncertainty in water supply reliability and place additional importance on long-term water resource planning, conservation, and resilience measures.

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Table 4-13: Drought Classifications and Impacts
Category Description Possible Impacts
D0
Abnormally
Dry
▪ Soil is dry; irrigation delivery begins early
▪ Dryland crop germination is stunted
▪ Active fire season begins
D1
Moderate
Drought
▪ Dryland pasture growth is stunted; producers give supplemental feed to cattle ▪ Landscaping and gardens need irrigation earlier; wildlife patterns begin to change ▪ Stock ponds and creeks are lower than usual
D2
Severe
Drought
▪ Producers increase water efficiency methods and drought-resistant crops ▪ Grazing land inadequate
▪ Fire season is longer, with high burn intensity, dry fuels, and large fire spatial extent, more fire crews on staff
▪ Lake- and river-based tourism declines; boat ramps close ▪ Trees are stressed; plants increase reproductive mechanisms; wildlife diseases increase
▪ Water temperatures increase; programs to divert water to protect fish begin ▪ River flows decrease; reservoir levels are low and banks are exposed D3
Extreme
Drought
▪ Federal water is not adequate to meet irrigation contracts; extracting supplemental groundwater is expensive
▪ Fire season lasts year-round; fires occur in typically wet parts of the state; burn bans are implemented
▪ Ski and rafting business are low; mountain communities suffer ▪ Low water levels impede fish migration and cause lower survival rates ▪ Wildlife encroaches on developed areas; little native food and water is available for bears, which hibernate less
▪ Water sanitation is a concern; reservoir levels drop significantly; surface water is nearly dry; flows are very low; water theft occurs
▪ Livestock need supplemental feed, cattle and horses are sold; little pasture remains ▪ Well and aquifer levels decrease; homeowners drill new wells D4
Exceptional
Drought
▪ Fire season is very costly; number of fires and areas burned are extensive ▪ Many recreational activities are affected
▪ Fields are left fallow; orchards are removed; vegetable yields are low; honey harvest is small; agricultural unemployment is high, food aid is needed ▪ Fish rescue and relocation begin; pine beetle infestation occurs; forest mortality is high; wetlands dry up; wildlife death is widespread; algae blooms appear ▪ Poor air quality affects health: greenhouse gas emissions increase as hydropower production decreases; West Nile outbreaks rise
▪ Water shortages are widespread; surface water is depleted; federal irrigation water deliveries are curtailed; water prices are extremely high; wells are dry, more and deeper wells are drilled; water quality is poor
Source: Adapted from U.S. Drought Monitor Drought Classifications and Impacts CAL OES SUBMITTAL - JUNE 2026
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Figure 4-18: Drought Severity Timeline 2000-2024
Dam Failure
Dam failure is a lower-probability but high-consequence hazard for the City of St. Helena due to its downstream location from several reservoirs. Dam failure refers to the partial or complete structural failure of an upstream dam, resulting in the uncontrolled release of stored water. Although there are no major dams located within St. Helena city limits, failure of an upstream dam could generate rapid downstream flooding affecting portions of the city.

Potential causes of dam failure include extreme precipitation events that exceed design capacity, seismic activity, internal erosion or piping, slNope instability, aging infrastructure, or operational issues.

Earthquakes are a particular concern in Napa County, where strong ground shaking could compromise dam embankments, spillways, or outlet works. Climate change may also increase stress on dam systems by intensifying storm events and altering hydrologic conditions.

Dam failure events differ from typical riverine flooding in that floodwaters may arrive with little warning, high velocity, and significant destructive force, greatly increasing risks to life safety, structures, transportation corridors, and utilities. Because warning times may be limited, emergency preparedness, public awareness, and evacuation planning are critical components of risk reduction.

Dam safety oversight, inspection, and emergency action planning are managed at the state and regional levels, including by the California Department of Water Resources and the California Division of Safety of Dams. These agencies work with dam owners and local jurisdictions to monitor dam conditions and coordinate emergency notification procedures.

Dam inundation describes the geographic areas that could be flooded as a result of a dam failure upstream.

Inundation mapping identifies where floodwaters would travel and accumulate if a failure were to occur.

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The Dam Inundation Exposure map, Figure 4-19, shows that inundation zones in St. Helena are primarily concentrated along the western portion of the city near the Napa River corridor and other low-lying terrain.

These areas reflect natural flow paths where floodwaters would be conveyed downstream under a dam failure scenario.

Exposure analysis indicates that approximately 600 residents and close to 100 parcels fall within these areas, with an estimated $94 million in building improvement value and $83 million in contents value exposed. Several high-potential-loss facilities and transportation and lifeline facilities are also located within inundation zones, underscoring the potential for service disruptions and access limitations during a dam-related flood event.

Dam inundation flooding can result in deep, fast-moving water capable of causing severe structural damage, roadway washouts, utility failures, and long-term economic disruption. Because these areas may experience flooding rapidly following a dam failure, evacuation and emergency response may be challenging, particularly in locations with limited access routes.

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Figure 4-19: Exposure Summary – City of St. Helena Dam Inundation Zone CAL OES SUBMITTAL - JUNE 2026
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Severe Weather Hazard
Severe storms are a recurring hazard in St. Helena, typically driven by high winds, heavy rainfall, and atmospheric river events during the winter months. While tornadoes, hail, and snow are rare in the region, severe storm impacts can be significant due to the city’s vulnerable infrastructure, older housing stock, and concentrations of at-risk populations.

Residents in mobile homes and older housing, many of whom are low-income or elderly, are particularly vulnerable during storm events. These households face heightened risks from power outages, mobility limitations, and health impacts during prolonged high-wind or heavy-rain events.

High winds frequently cause downed trees and power lines in and around St. Helena, leading to widespread power outages, communication disruptions, and blocked roadways. Such conditions strain emergency response capabilities, delay evacuations, and exacerbate challenges for dependent populations.

Heavy rainfall during atmospheric river events can overwhelm St. Helena’s aging stormwater infrastructure, especially in older downtown areas and low-lying neighborhoods near culverts and sloughs. These localized flash floods result in hazardous road conditions, temporary isolation of neighborhoods, and damage to property and infrastructure.

Severe storm frequency and intensity are projected to increase because of climate change. St. Helena already faces winter storms and recurring atmospheric rivers, which are contributing to repeated road closures, localized flooding, and long-term infrastructure strain. Climate-driven changes to storm severity highlight the city’s continued vulnerability to cascading hazards, including flooding and slope instability along the slough system.

While severe storms in St. Helena may not produce catastrophic destruction, their compounding effects on vulnerable populations, lifeline infrastructure, and mobility make them a critical hazard for ongoing mitigation planning. Strategies to reduce risk should prioritize hardening power and drainage systems, enhance stormwater infrastructure, and develop targeted preparedness and response measures that reach the city’s most at-risk residents.

Extreme Heat Hazard
The City of St. Helena’s inland valley location and reliance on outdoor agricultural labor make it particularly sensitive to rising temperatures and more frequent extreme heat days. While the bay influence of San Pablo Bay provides some natural moderation, climate change is projected to increase both the frequency and intensity of heat waves in the region, posing growing risks to public health, agriculture, and infrastructure.

The frequency of extreme heat days is projected to rise significantly across inland Napa County by midcentury. By the end of the century, the number of warm nights—when temperatures remain elevated and prevent recovery from daytime heat—is also projected to increase dramatically.

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Heat waves are becoming more common across California, with projections showing a significant rise in the number of extreme heat days by mid-century. In St. Helena, outdoor agricultural workers face elevated risks during extreme heat events, particularly those without access to shaded rest areas, cooling stations, or protective equipment. Seniors, low-income residents, and individuals in older housing stock without air conditioning are also especially vulnerable to heat-related illness and may lack transportation to reach cooling centers. In addition, the city can experience power outages due to heat events and increased demand on the grid during peak hours.

According to Cal-Adapt, St. Helena will likely experience a climate change-driven increase in extreme heat days from four days per year to 18 days per year by the end of the century under a medium emissions scenario (RCP 4.5). Over the same time period, the city is also likely to see an increase in warm nights from four per year to 36. Table 4-14 explains the extreme heat event thresholds for St. Helena.

Table 4-14: Cal-Adapt Extreme Heat Thresholds
Term Cal-Adapt Definition
Thresholds for
City of St. Helena
Extreme
Heat Day
Defined as a day in a year when the daily maximum/minimum temperature exceeds the 98th percentile of daily maximum/minimum temperatures based on observed historical data from 1961-1990 between April and October. 101.3°F
Warm Night
Defined as a day in April through October when daily minimum temperature exceeds the 98th historical percentile of daily minimum temperatures, based on observed data from 1961-1990 between April and October.

63.3°F
Heat Wave Defined as four consecutive days or nights above the extreme heat / warm night threshold.
3 days ≥ 101.3°F
or 4 nights ≥

63.3°F
Source: Cal-Adapt Extreme Heat Days and Warm Nights Tool For St. Helena, this means disproportionate impacts on its agricultural workers as well as low-income households with limited adaptive capacity. Further, with almost 40% of the population over 65 years and a significant percentage of people living with disabilities, much of the St. Helena community may be susceptible to extreme heat impacts.

Extreme heat often coincides with elevated wildfire risk, reduced air quality from ozone and particulates, and public safety power shutoffs designed to prevent utility-caused ignitions. These secondary hazards can compound vulnerabilities by cutting access to cooling or disrupting medical care reliant on electricity.

Climate Change Hazard
Average annual temperatures across most of California have already increased by more than 1°F, with some areas experiencing rises of over 2°F when comparing the 1901 to 1960 average to that of 1986 to 2016. Daily CAL OES SUBMITTAL - JUNE 2026
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maximum temperatures—a key indicator of extreme heat—are projected to increase by 4.4°F to 5.8°F by 2050 and by 5.6°F to 8.8°F by 2100. Heat waves that impact public health, known as heat-health events, are also expected to intensify across the state. By 2050, these events are projected to last up to two weeks longer in the Central Valley and occur four to ten times more often in the Northern Sierra region (California Natural Resources Agency, 2022).

California is already experiencing significant impacts from climate change, including prolonged drought, a lengthened wildfire season, increased coastal flooding and erosion, and widespread tree mortality. The state has observed rising average temperatures, more extreme heat days, fewer cold nights, a longer growing season, and shifts in the water cycle, with less winter precipitation falling as snow. In addition, summertime fog has declined by approximately 33%, and both snowmelt and rainwater runoff are occurring earlier in the year (Cal OES, 2018).

Long-term trends indicate a 12% to 20% decline in fog across California from 1900 through projections to 2070. Climate experts suggest that warming temperatures reduce the ability of air masses to cool enough to produce fog, which plays a critical role in supporting California’s ecosystems (Grantham, Teodore; University of California, Berkeley, 2018).

The City of St. Helena is increasingly vulnerable to the long-term impacts of climate change, which function as hazard multipliers across the Napa Valley and broader North Bay region. St. Helena’s location within an inland valley, combined with its proximity to San Pablo Bay and surrounding upland areas, creates a complex climate setting that is sensitive to shifts in temperature, precipitation patterns, and seasonal variability. Projected changes in these conditions are expected to intensify existing hazards, including flooding, severe weather, drought, and wildfire.

Precipitation, Storms & Flooding
Although total annual precipitation may not significantly increase, climate projections indicate that rainfall is more likely to occur in fewer, more intense storm events. These high-intensity storms, often associated with atmospheric river systems, increase the risk of riverine flooding along the Napa River as well as localized flooding in urban areas with constrained drainage systems.

Intense rainfall following extended dry periods can also increase the risk of erosion, localized slope instability, and debris flows, particularly in hillside areas surrounding the valley floor and along transportation corridors. These conditions can impact critical infrastructure, damage roadways, and disrupt emergency access. In addition, sea level rise combined with higher peak flows in the Napa River and its tributaries may exceed existing system capacity during extreme events, contributing to flooding beyond currently mapped floodplain boundaries.

Drought & Water Reliability
Climate change is expected to result in more frequent and prolonged drought conditions across Napa County. While the City of St. Helena benefits from a combination of local and regional water sources, extended dry periods can reduce water availability, increase demand, and place stress on both surface water CAL OES SUBMITTAL - JUNE 2026
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and groundwater systems. Reduced precipitation and earlier snowmelt in upstream watersheds may affect reservoir storage and seasonal water supply reliability.

Drought conditions also have broader environmental and hazard implications. Reduced soil moisture and vegetation stress increase susceptibility to wildfire in surrounding areas, while also affecting urban landscaping and tree canopy health within the city. Prolonged dry conditions may also impact local creeks and riparian systems, which play an important role in stormwater conveyance, habitat, and groundwater recharge.

Wildfire & Vegetation Change
Climate-driven increases in temperature and changes in precipitation patterns are expected to extend the wildfire season and increase fire risk in areas surrounding the City of St. Helena. While much of the city is urbanized, it is bordered by wildland and open space areas that are susceptible to wildfire. Fires in surrounding areas can affect the city through evacuation impacts, degraded air quality, and strain on emergency services.

Changes in vegetation patterns, including increased tree mortality and shifts in species composition, may contribute to higher fuel loads over time. Even when wildfire does not directly impact the city, smoke and poor air quality can have significant public health consequences, particularly for sensitive populations.

Cascading Effects
Climate change amplifies interactions between hazards, creating compounding risks for the City of St.

Helena. These cascading effects underscore the importance of integrating climate considerations into hazard mitigation planning, infrastructure investment, emergency preparedness, and community outreach.

As climate conditions continue to evolve, proactive planning will be critical to reducing long-term risk and enhancing community resilience.

4.5.3 Climate Change Impacts & Vulnerable Populations
Climate change is expected to exacerbate many of the natural hazards affecting the City of St. Helena, increasing risks to populations that already face social, economic, or physical vulnerabilities. Rising temperatures, more extreme precipitation events, prolonged drought, sea level rise, and increased frequency of extreme heat are projected to intensify existing hazard conditions and create new challenges for public health, safety, and emergency response.

Certain populations in St. Helena are more likely to experience disproportionate impacts from climaterelated hazards. Older adults, individuals with disabilities, low-income households, renters, and households with limited English proficiency may have reduced capacity to prepare for, respond to, and recover from climate-driven events. These groups may face barriers related to mobility, access to transportation, financial resources, housing stability, or timely access to emergency information.

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Extreme heat presents a growing risk to vulnerable populations, particularly elderly residents, individuals with underlying health conditions, outdoor workers, and households without adequate cooling. Heat waves can increase the incidence of heat-related illness, strain electrical systems, and worsen air quality, especially when combined with wildfire smoke. Low-income households may be less able to afford cooling costs or make energy-efficient upgrades, increasing exposure during prolonged heat events.

Flooding and sea level rise disproportionately affect residents and workers in flood prone areas near the Napa River. Vulnerable populations living or working in these areas may face greater risk of displacement, property damage, and disruption of access to essential services. Flood events can also impact transportation routes and utilities, creating additional challenges for individuals who rely on public transit, medical equipment, or nearby services.

Drought and water scarcity can place added burdens on vulnerable populations by increasing utility costs, limiting access to cooling and landscaping, and reducing the resilience of natural systems that provide flood protection and cooling benefits. For low-income households and fixed-income seniors, increased water and energy costs associated with drought and heat can compound financial stress.

Climate change may also increase the frequency and duration of poor air quality events, particularly from regional wildfires. Individuals with respiratory conditions, older adults, children, and outdoor workers are especially sensitive to smoke exposure. Limited access to air filtration, clean indoor environments, or protective equipment can further increase health risks for vulnerable populations.

4.5.4 Hazard Problem Statements
As part of the mitigation action identification process, the Planning Team for each jurisdiction identified areas of concern (aka problem statements) for their respective facilities based on the risk assessment and vulnerability analysis, utilizing the RAMP mapping and static snapshot maps. Problem statements focused on the impact, victim, or threat that the hazard could create in the jurisdiction, as described in Table 4-15.

Identifying common issues and weaknesses through these problem statements assisted the planning group in understanding the realm of resources needed for mitigation.

The goal is to have at least one mitigation action for every problem statement. Projects or actions have been developed to mitigate each problem identified. See Table 4-17 for a full list of mitigation actions and corresponding problem statements that they address. Each problem statement is coded with a problem number for cross-referencing between Table 4-15 and Table 4-17 Table 4-15: City of St. Helena Hazard Problem Statements Problem No. Hazard Area of
Concern
Primary
Agency
Problem Description Related MA
ps-CC-SH-329 Climate
Change
Threat City of St.

Helena
Climate change is expected to increase the
frequency and intensity of existing hazards,
amplifying the impacts of extreme heat,
drought, severer weather, wildfire, and flood.
ma-AH-SH-7, maAH-SH-8, ma-AHSH-9, ma-DR-SH29, ma-FL-SH-71, ma-WF-SH-103
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Problem No. Hazard Area of
Concern
Primary
Agency
Problem Description Related MA
ps-DF-SH-27 Dam Failure Victim City of St.

Helena
There are almost 600 residents and hundreds
of parcels exposed to dam inundation
associated with Bell Canyon and other
upstream dams, creating life-safety and
service disruption risks in St. Helena.
ma-FL-NCo-52,
ma-FL-NCo-56,
ma-DF-NCo-120,
ma-DF-SH-222,
ma-FL-SH-71
ps-DF-SH-330 Dam Failure Impact City of St.

Helena
Dam failure could damage or disrupt several
critical facilities, including key transportation
routes, water and wastewater infrastructure,
and electric systems, hindering evacuation
and emergency response and complicating
recovery efforts.
ma-FL-SH-71,
ma-DF-SH-222
ps-DR-SH-54 Drought Threat City of St.

Helena
Residents lack clear, consistent information
on drought stages, water rationing
requirements, and available assistance
programs during multi-year droughts.
ma-DR-SH-29
ps-DR-SH-55 Drought Impact City of St.

Helena
Increasingly frequent and severe droughts
heighten wildfire risk, stress water supplies for
firefighting and cooling, and strain the City’s
ability to maintain service levels.
ma-DR-SH-30
ps-DR-SH-331 Drought Victim City of St.

Helena
Seniors, medically vulnerable residents, and
low-income households are disproportionately
impacted by water rate increases and use
restrictions during drought, with fewer
resources to adapt.
ma-DR-SH-29,
ma-AH-SH-7, maAH-SH-9
ps-EQ-SH-68 Earthquake Victim City of St.

Helena
About 5,400 residents, including many seniors
in Vineyard Valley, Woodbridge Village, and
Silverado Orchards areas, live in severe
shaking zones associated with the West Napa
Fault and face disproportionate risk due to age,
mobility, and housing type.
ma-EQ-SH-44,
ma-AH-SH-9, maAH-SH-7, ma-AHSH-8
ps-EQ-SH-86 Earthquake Impact City of St.

Helena
A major earthquake could damage or destroy
homes, businesses, and critical facilities; cause
long-duration power and utility outages;
displace residents; strain services for those
who are ill-prepared needing food and water;
disrupt tourism; and overburden public safety
and city staff.
ma-EQ-SH-44,
ma-AH-SH-8, maAH-SH-7, ma-AHSH-9
ps-EQ-SH-331 Earthquake Threat City of St.

Helena
Local bridges, older water transmission lines,
and seismically vulnerable wastewater and
stormwater infrastructure are at risk of
significant damage in a major earthquake,
threatening evacuation circulation and
community lifelines, including water delivery.
ma-AH-SH-8, maFL-SH-71
ps-HH-SH-397 Extreme Heat Threat City of St.

Helena
The number of extreme heat days and warm
nights is anticipated to increase significantly
by the end of the century.
ma-AH-SH-8, maAH-SH-9
ps-HH-SH-398 Extreme Heat Victim City of St.

Helena
Outdoor workers, seniors, people with
disabilities, and those without adequate shelter
are disproportionately impacted by extreme
heat events, including heat illness and
economic stress.
ma-AH-SH-9
ps-HH-SH-399 Extreme Heat Impact City of St.

Helena
Increased electricity demand and strain on the
grid during extreme heat events can cause
power outages, impacting people, utilities, and
public services.
ma-AH-SH-8
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Problem No. Hazard Area of
Concern
Primary
Agency
Problem Description Related MA
ps-FL-SH-112 Flood Victim City of St.

Helena
Flooding along the Napa River can affect
hundreds of residents living in the 100- and
500-YR floodplains.
ma-FL-NCo-53,
ma-FL-SH-70,
ma-FL-SH-71,
ma-AH-SH-7
ps-FL-SH-118 Flood Victim City of St.

Helena
St. Helena has at least one RL property on Pope
Street, indicating ongoing, localized flood risk
that has resulted in multiple paid NFIP claims.
ma-FL-SH-69,
ma-FL-SH-70,
ma-AH-SH-7, maFL-SH-71
ps-FL-SH-131 Flood Impact City of St.

Helena
Flood events can damage or destroy structures
and vineyards; disrupt business operations
and tourism; displace residents and require
evacuation and sheltering; and place
prolonged demands on public safety and City
staff.
ma-FL-SH-69,
ma-FL-SH-71,
ma-AH-SH-7
ps-FL-SH-135 Flood Impact City of St.

Helena
Debris accumulation and high flows at the
Pratt Avenue and Pope Street bridges, storm
drain outfalls, and riverbanks can obstruct
water flow, worsen localized flooding, and
damage adjacent infrastructure and property.
ma-FL-SH-71
ps-SW-SH-334 Severe
Weather
Impact City of St.

Helena
Severe winter storms and atmospheric river
events can down trees, damage the urban
forest, block roads, and cause power outages
and utility disruptions, leading to temporary
isolation and service interruptions.
ma-FL-SH-71,
ma-AH-SH-9, maAH-SH-8, ma-AHSH-7
ps-SW-SH-335 Severe
Weather
Victim City of St.

Helena
Seniors, medically dependent residents, and
households without backup power or reliable
transportation are especially vulnerable to
extended outages and limited mobility during
severe storms and high-wind events.
ma-FL-SH-71,
ma-AH-SH-7, maAH-SH-8, ma-AHSH-9
ps-SF-SH-332 Slope Failure Impact City of St.

Helena
Multiple critical facilities and miles of
infrastructure could be damaged or blocked
from repair and maintenance access due to
landslides or other slope failures.
ma-SF-SH-223,
ma-FL-SH-71
ps-SF-SH-333 Slope Failure Victim City of St.

Helena
Approximately 500 residents live in high
landslide susceptibility areas, exposing them
to isolation risks from damaged lifelines in a
major slope failure event.
ma-FL-SH-71,
ma-SF-SH-223
ps-WF-SH-186 Wildfire Impact City of St.

Helena
Wildfires can generate prolonged smoke and
poor air quality; damage structures and
vineyards; cause power outages and road
closures; strain sheltering and health care
facilities; impact businesses and tourism; and
create long work hours and stress for public
safety and City staff.
ma-WF-SH-103,
ma-AH-SH-7, maAH-SH-8, ma-AHSH-9
ps-WF-SH-192 Wildfire Victim City of St.

Helena
Residents, visitors, and businesses within and
adjacent to the WUI, including seniors in
Silverado Orchards, Hunts Grove, Stone Bridge
Apartments, Culinary Institute dorms,
Woodbridge Village, and Vineyard Valley and
students at local schools, are at risk of
evacuation, displacement, smoke inhalation,
and lifeline disruption during a wildfire.
ma-WF-SH-103,
ma-WF-SH-104,
ma-WF-SH-106,
ma-AH-SH-7, maWF-SH-103
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Problem No. Hazard Area of
Concern
Primary
Agency
Problem Description Related MA
ps-WF-SH-197 Wildfire Threat City of St.

Helena
Extensive WUI areas, fuel buildup following
wet winters, and human ignition sources (e.g.,
equipment use, debris burning, and arson)
increase the threat of fast-moving wildfires
impacting St. Helena and nearby critical water
facilities. According to the California Board of
Forestry’s Assessment 220 structures in “High”
severity zone. 8 structures in “Very High”
severity zone.
ma-WF-SH-104,
ma-WF-SH-105,
ma-WF-SH-103

4.6 Mitigation Strategy
This section provides the framework for how the City of St. Helena will reduce hazard risk within its jurisdiction while supporting the broader goals of the Napa County MJHMP. It includes an overview of existing capabilities, opportunities to strengthen resilience, and the city’s prioritized mitigation actions.

Together, these elements demonstrate how St. Helena integrates hazard awareness into its planning and development processes while contributing to a coordinated countywide approach.

Within the Napa County MJHMP, the mitigation strategy serves as the roadmap for future hazard mitigation efforts. For St. Helena, the strategy outlined in this annex reflects the outcomes of the countywide planning process while also addressing the city’s unique risks, priorities, and community needs. The strategy is designed to reduce vulnerabilities identified in the risk assessment, including the problem statements developed for flooding, earthquakes and liquefaction, slope failure, wildfire, drought, severe storms, extreme heat, and climate change.

Mitigation actions identified in this annex include both policy-based and project-based initiatives, with an emphasis on integrating resilience into land use planning, infrastructure investments, and community programs. Actions are structured to align with FEMA’s requirements and to coordinate with existing city, county, and regional planning mechanisms. Each action identifies responsible parties, potential funding sources, and the resources needed for implementation.

For St. Helena, this strategy provides a framework for strengthening resilience by combining city-led initiatives, such as infrastructure improvements, building code enforcement, and community preparedness, with regional coordination through the MJHMP. By advancing these efforts in alignment with the General Plan and other local planning documents, St. Helena enhances its ability to reduce hazard risk while supporting long-term community safety, sustainability, and economic stability.

The subsections that follow describe these elements in detail:
▪ Sections 4.6.1, Capabilities and Opportunities, provides a summary of the city’s capacity to address natural hazards.
▪ Section 4.6.2, Mitigation Action Plan, presents St. Helena’s prioritized actions to guide implementation in coordination with countywide strategies.

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▪ Section 4.6.3, Status of Previous Mitigation Actions, provides a summary of all previous actions and their current status, whether completed, cancelled, or revised.

Aligning the Action Plan
This section connects St. Helena’s mitigation actions with its existing capabilities and areas for growth.

Capability assessments are a required element of hazard mitigation planning under the Disaster Mitigation Act of 2000 and FEMA’s 2023 guidance, ensuring that actions are realistic, achievable, and aligned with available resources.

The section begins with a summary of St. Helena’s capabilities across four areas: planning and regulatory, administrative and technical, fiscal, and education and outreach. This overview highlights the tools and strengths that the district already uses to reduce hazard risk. The section then provides a detailed analysis of each capability area, identifying both current practices and opportunities to expand resilience.

4.6.1 Capabilities & Opportunities
This section provides a detailed assessment of the city’s current capabilities to support hazard mitigation, as well as future opportunities. This consists of describing how the city is planning for hazards and growth and a summary of its existing capabilities and the potential for enhancement.

Planning for Hazards & Growth
As a general law city, the City of St. Helena manages growth within the framework of California’s comprehensive planning, zoning, subdivision, and environmental regulations. Much of the City’s developable land has already been urbanized, and remaining growth is largely directed toward infill development, redevelopment, and planned buildout within the existing urban footprint. St. Helena is bisected by the Napa River, with hillside terrain to the west and east, which constrains outward expansion and concentrates future development in areas already subject to natural hazards.

This development pattern places portions of the city’s population, infrastructure, and economic assets within areas exposed to hazards such as riverine flooding along the Napa River, dam inundation zones, strong earthquake ground shaking and liquefaction, and extreme heat and drought conditions. Industrial and commercial areas near the river corridor and residential neighborhoods in low-lying areas are particularly sensitive to flooding, while hillside areas east of the city face localized risks related to slope instability and wildfire exposure.

Hazard vulnerability is addressed through coordination with the city’s General Plan, particularly the Safety Element, which integrates hazard information into land use decisions, infrastructure planning, and development review. This approach ensures that growth and redevelopment consider site-specific risks and incorporate appropriate mitigation measures, such as flood-resilient design, geotechnical stabilization, and emergency access planning. Integration of hazard considerations into long-range planning also supports compliance with state and federal hazard mitigation requirements and strengthens the City’s eligibility for disaster recovery and resilience funding.

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Climate change is expected to intensify several of the hazards affecting St. Helena, including more extreme precipitation events, prolonged drought, and increasing extreme heat. As growth continues within constrained and hazard-exposed areas, resilience must be embedded into every phase of planning and development. Growth management in St. Helena therefore emphasizes sustainable building practices, water conservation, protection of natural floodplain functions, and climate-adaptive infrastructure, ensuring that future development and redevelopment reduce, rather than exacerbate, existing hazard risks and support long-term community resilience.

Long-Range Planning & Growth Management
Long-range planning and growth management policies play a central role in limiting hazard exposure in St.

Helena. The city’s General Plan establishes the overall land use pattern, directs growth toward areas that can be safely and efficiently served by infrastructure, and discourages development in areas subject to significant natural hazards where feasible.

Growth in St. Helena has largely occurred within an established urban footprint, with an emphasis on infill development, redevelopment, and planned expansion areas that are supported by existing transportation, utility, and emergency services. This approach helps reduce the need for development in hazard-prone areas such as floodplains, steep slopes, and wildfire-prone wildland–urban interface locations. Where development does occur near hazard areas, planning policies emphasize hazard-aware site design, infrastructure resilience, and emergency access.

Long-range planning efforts also account for future climate conditions, recognizing that sea level rise, extreme heat, drought, and more intense storm events may alter hazard profiles over time. Incorporating these considerations into growth management helps ensure that future development does not increase vulnerability or place undue strain on emergency response and public services.

Building Codes & Development Standards
St. Helena’s development strategies combine comprehensive planning frameworks with robust regulatory measures to guide growth while reducing risks from natural hazards. Building codes play a central role in this approach. Nationally, continual improvements to building codes since 1990 have added only about one percent to construction costs while greatly improving disaster resilience (National Institute of Building Sciences, 2019). In California, building codes are among the most stringent in the world, setting minimum standards that safeguard against hazards such as earthquakes, flooding, wildfire, landslides, and severe weather. St. Helena enforces these standards locally, providing a strong foundation for resilient construction.

The city is required to regularly update its development regulations to reflect the California Building Code (CBC), which is revised every three years and was most recently updated in 2025. The CBC establishes some of the world’s highest construction standards, ensuring occupant safety in the face of natural hazards.

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adaptation measures. In addition, St. Helena participates in the National Flood Insurance Program (NFIP), requiring that all new development in designated flood hazard areas meet FEMA’s minimum flood protection standards.

Through these building and development regulations, St. Helena ensures that new development in hazardprone areas is either restricted or subject to strict hazard-mitigation requirements. Where development is allowed, codes emphasize reducing exposure and vulnerability through appropriate siting, advanced construction techniques, emergency access, and defensible space. For example, new construction in the wildland–urban interface (WUI) must comply with fire-resistant building materials and vegetation management requirements under the California Fire Code.

Beyond code enforcement, St. Helena integrates these mandates into broader local planning frameworks, including the General Plan and HMP This alignment ensures that growth management, environmental review, and hazard mitigation strategies collectively address emerging risks from wildfire, drought, flooding, extreme heat, and severe weather intensified by climate change.

California Environmental Quality Act (CEQA) & Hazard Mitigation The California Environmental Quality Act (CEQA) requires General Plans, Specific Plans, and major development projects to evaluate hazards such as seismic risk and wildfire. Environmental documents must identify these risks and propose mitigation measures, which may include setbacks from hazard-prone areas, infrastructure upgrades, evacuation planning, or restrictions on development in high-risk zones.

Regional and state public safety planning frameworks that inform development review in St. Helena include the State Seismic Hazards Mapping Act, the California Environmental Quality Act (CEQA) and its Guidelines, California Noise Insulation Standards (Title 24), and the Federal Emergency Management Agency (FEMA) Flood Insurance Program. Together, these programs establish requirements for evaluating and mitigating environmental and hazard-related impacts associated with development.

Under CEQA, residential projects that require discretionary approval from the city are subject to environmental review concurrently with the approval process. While CEQA review can add time to development and is therefore considered a potential constraint to housing production, much of St. Helena’s remaining vacant and developable land has already undergone environmental review through Environmental Impact Reports (EIRs) prepared as part of adopted specific plans. These EIRs streamline subsequent project-level CEQA review by identifying environmental impacts and mitigation measures in advance, allowing later residential projects to tier from or rely on existing CEQA documents. Projects that deviate from the assumptions or scope of adopted specific plans may also tier from previously certified CEQA analyses, where appropriate.

Recent updates to CEQA standards have also changed how transportation and air quality impacts are evaluated. Transportation impacts are no longer assessed using Level of Service (LOS), which measured vehicle delay, but instead rely on Vehicle Miles Traveled (VMT) as the primary metric. This shift emphasizes reducing vehicle travel and associated emissions rather than roadway congestion.

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In addition, updated Bay Area Air Quality Management District (BAAQMD) greenhouse gas (GHG) thresholds, adopted in April 2022, require changes to how GHG impacts are analyzed in CEQA documents. Under these standards, plans or projects within BAAQMD jurisdiction must either demonstrate consistency with an adopted, qualified local Climate Action Plan or incorporate specific project features, including all-electric buildings, a minimum reduction in VMT, and electric vehicle infrastructure meeting CalGreen Tier 2 requirements.

Although LOS is no longer used for CEQA compliance, the city continues to use LOS analysis as a non-CEQA planning tool to evaluate roadway operations, support infrastructure planning, and ensure that key transportation corridors function effectively and meet community expectations. Together, CEQA and related regulatory frameworks play a critical role in integrating hazard mitigation, climate adaptation, and sustainability considerations into development and long-range planning decisions in St. Helena.

By integrating hazard analysis into the development review process, CEQA helps ensure that future growth in St. Helena is designed with resilience and long-term community safety in mind.

Development & Hazard Considerations
Development in the City of St. Helena occurs within a physical and regulatory context shaped by natural hazards, environmental constraints, and long-term growth management policies. As a general law city operating under California planning and environmental regulations, St. Helena evaluates development proposals with consideration for hazard exposure, public safety, infrastructure capacity, and long-term resilience. This integrated approach helps ensure that new development and redevelopment do not increase risk to people, property, or critical systems.

Much of the city’s remaining development potential lies within areas that are already urbanized or planned through adopted specific plans. As a result, development often occurs in proximity to known hazard areas, including floodplains along the Napa River, dam inundation zones, liquefaction-prone soils, and areas exposed to strong seismic shaking and extreme heat. Rather than avoiding development entirely in these locations, the city emphasizes risk-informed site planning, design, and construction standards to reduce vulnerability and limit potential impacts.

Flood hazards are addressed through enforcement of flood plain management regulations, participation in the National Flood Insurance Program, and incorporation of flood-resilient design measures for development in or near mapped flood hazard areas. These measures may include elevating structures, protecting utilities, maintaining flood conveyance, and avoiding critical facilities in the highest-risk locations. Development decisions also consider future flood conditions associated with more intense storm events.

Seismic hazards are a key consideration in development review due to the City’s location within the seismically active San Francisco Bay Area. Projects are required to comply with state seismic design standards and, where appropriate, conduct site-specific geotechnical investigations to address ground CAL OES SUBMITTAL - JUNE 2026
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shaking, liquefaction, and slope stability. These requirements help reduce structural damage and protect infrastructure during earthquake events.

Wildfire, slope failure, and extreme weather hazards are also considered during development review, particularly in areas near the eastern hills, open space, and transportation corridors. Development standards related to defensible space, access, drainage, and emergency response are used to minimize risk and support safe evacuation and emergency operations.

The CEQA provides a framework for identifying hazard-related impacts at the project level and requiring feasible mitigation measures. Through CEQA review, the city evaluates whether proposed development would expose people or structures to significant risks from natural hazards and ensures that appropriate avoidance, design, or mitigation measures are incorporated into project approvals.

Capabilities & Opportunities Assessment
To develop a realistic and actionable mitigation strategy, it must account for existing jurisdictional capabilities and what future opportunities there are to enhance those capabilities for purposes of hazard mitigation. This section provides an assessment of the City of St. Helena’s existing capabilities and future opportunities, including planning and regulatory, administrative and technical, fiscal, and public outreach and education capabilities. This assessment also identifies opportunities to integrate this MJHMP into future planning, policies, or programs to weave mitigation efforts into daily operations and address hazard problems wholistically. Capabilities are categorized into four groups and include various mechanisms. ▪ Planning and Regulatory Capabilities: Existing long-range plans, emergency response plans, hazard-specific plans, land use policies, and building and development standards. ▪ Administrative and Technical Capabilities: Available expertise in emergency services, engineering, grant management, and community planning.
▪ Fiscal Capabilities: Budgetary capacity, taxing authority, grants, and other funding mechanisms that can support mitigation projects.
▪ Outreach and Education Capabilities: Existing programs for providing technical assistance, community education, public warnings, and stakeholder engagement.

A full description of the process used to develop the capabilities assessment is provided in Volume 1, Section

2.3.3. This capabilities and opportunities assessment for St. Helena lists the various types of capabilities along with how they have been, currently are, or will in the future be integrated into hazard mitigation planning efforts. The three “HMP Integration” columns that identify the capability’s status and usage are color-coded with green, yellow, or orange shading to communicate the following:
▪ Status: If the capability is present at all and what level of use it has generally. ▪ Current Mitigation Use: If the capability is currently being used in mitigation efforts, specifically, and at what level.

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▪ Future Opportunity: If there is a future opportunity to integrate the capability into mitigation efforts and at what level.

Summary of Capabilities & Opportunities
This Capabilities and Opportunities Assessment for the City of St. Helena summarizes the various types of capabilities it has for hazard mitigation currently. The assessment also identifies opportunities to integrate, expand, and improve the city’s capabilities for future hazard mitigation. Table 4-16 provides a comprehensive list of capabilities and identifies the current status, current mitigation use, and future opportunities.

Planning & Regulatory
The City of St. Helena has strong planning and regulatory capabilities that support hazard risk reduction and resilient development. The city enforces the California Building Code (Title 24) and locally adopted ordinances that address floodplain management, fire safety, stormwater control, water conservation, and development in inundation and hillside areas. These regulations are integrated into zoning, subdivision, and site plan review processes, ensuring that hazard considerations are addressed during development reviews.

Growth management is guided by policies in the city’s General Plan. Capital investments are prioritized through the Capital Improvements Program (CIP), which supports resilient infrastructure for water, storm drainage, transportation, and public services. St. Helena maintains several hazard reduction programs, including stormwater management and erosion control, water conservation through a water neutrality policy, and public outreach through the Alter Napa County emergency preparedness webpage. The city also promotes non-structural earthquake preparedness and household-level mitigation actions.

The City participates in the National Flood Insurance Program (NFIP) and enforces local floodplain management regulations supported by current FEMA flood mapping and elevation certificate records. While flood preparedness information is available, flood insurance education is limited, and the City does not currently participate in FEMA’s Community Rating System (CRS), representing a future opportunity for enhanced flood risk reduction.

Future integration of the MJHMP will occur through various processes and mechanisms outlined across multiple mitigation actions (Table 4-17). Key opportunities for future hazard mitigation integration with the City of St. Helena’s existing planning mechanisms include incorporating the updated risk assessment, hazard-specific vulnerability findings, and projected climate change impacts into the Emergency Preparedness Awareness Campaign (ma-AH-SH-7), and the All-Hazard Mitigation Education Program (maAH-SH-9).

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Administrative & Technical
The City of St. Helena has strong administrative and technical capacity to support hazard mitigation planning, implementation, and coordination. Core planning, engineering, and development review functions are housed within the Community Development Department. These staff provide expertise in land use planning, development review, infrastructure design, and enforcement of building and safety standards.

The city has access to qualified personnel for key hazard mitigation functions, including community planning, land development review, construction engineering, natural hazards analysis, transportation planning, and resilience planning. The Community Development Department provides building code administration, and the City Manager serves as the Floodplain Administrator and Director of Emergency Services, ensuring direct coordination between planning, emergency management, and floodplain compliance. Fire prevention and wildfire mitigation functions are supported by the St. Helena Fire Department through the Fire Marshal.

While the City does not have dedicated staff for public outreach, GIS, or grant management, these functions are addressed through shared responsibilities across departments and through coordination with regional partners such as Napa County, which provides GIS support. This shared staffing approach effectively supports current mitigation activities but represents an opportunity for enhancement as hazard mitigation, climate adaptation, and grant funding efforts expand.

Warning Systems & Services
The City of St. Helena has strong warning and emergency communication capabilities to alert residents, businesses, and visitors of hazardous conditions and emergency situations. The city utilizes the Alert Napa County emergency notification system as its primary platform for disseminating time-sensitive warnings related to natural hazards, evacuations, sheltering, and public safety incidents.

Emergency information is also communicated through city and partner social media channels, which provide rapid updates and situational awareness during evolving incidents. These electronic communication methods are supplemented by non-electronic outreach, including door-to-door notifications when necessary, and emergency vehicle sirens used by police and fire agencies to warn the public in affected areas.

This multi-channel approach helps ensure redundancy and increases the likelihood that critical information reaches residents with varying access to technology or communication needs. Warning systems support response to a range of hazards, including flooding, wildfire, earthquakes, extreme weather, and power shutoff events.

Fiscal
The City of St. Helena has moderate to strong fiscal capacity to support hazard mitigation through a combination of local revenues, fees, grants, and long-term financing tools. These funding mechanisms CAL OES SUBMITTAL - JUNE 2026
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support infrastructure maintenance, capital improvements, and implementation of hazard mitigation measures identified in city plans and programs.

The City collects utility fees for water, recycled water, and sewer services, which help fund infrastructure upgrades that support drought resilience, flood protection, and system reliability. System development and impact fees are also a key funding source and are assessed for traffic, housing, water and wastewater capacity, parks and recreation, civic facilities, General Plan implementation, and fire district mitigation.

These fees help ensure that new development contributes to infrastructure needed to safely accommodate growth.

St. Helena has the authority to use general obligation bonds and special tax or revenue bonds to finance large capital projects, providing flexibility to fund hazard mitigation–related infrastructure improvements when voter approval or project-specific revenues are available. The city also adopts a Capital Improvement Program (CIP) tied to the annual budget, which prioritizes investments in infrastructure that supports public safety and resilience.

Additional funding sources include Community Development Block Grants (CDBG), which can be used for hazard-related housing rehabilitation and infrastructure improvements, particularly for vulnerable populations. While special-purpose taxes and benefit assessments are not consistently used, the City has the authority to pursue voter-approved tax measures for specific purposes, such as public safety or infrastructure, representing a future opportunity to expand mitigation funding.

Education & Outreach
The City of St. Helena has strong education and outreach capabilities that support public awareness, preparedness, and risk reduction for natural hazards. The city maintains a dedicated emergency preparedness webpage, Alert Napa County which centralizes information on alerts, evacuations, flooding, wildfire, earthquakes, power shutoffs, and other hazards. This resource serves as the primary hub for hazard-related public information.

The city actively uses social media platforms, including City websites, Facebook, Instagram, LinkedIn, Nextdoor, Threads, X, and YouTube, to disseminate emergency information, preparedness messaging, and real-time updates during incidents. These digital tools are complemented by participation in annual public safety and preparedness events, such as the Great California ShakeOut and Ready Napa County initiatives.

St. Helena supports community-based preparedness through the Community Emergency Response Team (CERT) program and partnerships with regional organizations, including local Fire Safe Councils and the Napa Communities Firewise Foundation. The city also collaborates with the Napa County Resource Conservation District, which provides outreach related to wildfire, drought, and other environmental hazards.

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requests. While hazard information is primarily disseminated online, printed materials and library-based resources are used on a limited basis, representing an opportunity for expanded outreach to residents with limited digital access.

ASSESSMENT LEGEND
HMP Integration
Status Current Mitigation Use Future Opportunity
Currently in use or present. Used widely for mitigation. Opportunity to expand and integrate. (Sort of) Seldomly used or limited
presence.

Limited use in mitigation
planning.

Limited opportunity to expand and
integrate.
(No) Not present or available. Not used in mitigation planning.

No opportunity to expand or
integrate.

Table 4-16: City of St. Helena Capabilities and Opportunities Assessment HMP Integration Notes / Additional Detail
Resource Status
Current
Mitigation
Use
Future
Opportunity
Planning and Regulatory
Capabilities
Construction and Future
Development Regulations
Building Codes Green Green Green California Building Code (California Code of Regulations, Title 24) adopted under Title 15
BCEGS Rating 0 0 0
Public Protection (ISO Class) Green Green Green Class 3 Hazard-Related Development
Standards
Green Green Green
Fire Hazard Severity Zones (Ch 8.44); Stormwater
and Runoff Pollution Control (Ch 13.32); Fire Code
(Ch 15.35); Retrofitting of Unreinforced Masonry
Buildings (15.40); Flood Damage Prevention (Ch

15.52); Subdivisions (Title 16); Zoning Code (Title 17); Environment (Title 18)
Zoning Ordinance
Yellow Yellow Yellow
Title 17 Zoning Code establishes districts and
standards that address flood, drought, and fire
hazards
Hazard-Specific Ordinance
Green Green Green
Fire Hazard Severity Zones (Ch 8.44); Stormwater
and Runoff Pollution Control (Ch 13.32); Fire Code
(Ch 15.35); Retrofitting of Unreinforced Masonry
Buildings (15.40); Flood Damage Prevention (Ch

15.52); Water Shortage Emergency Ordinance; Water
Use Efficiency and New Development (Ch 13.12)
Growth Management Ordinance Yellow Yellow Green 2040 General Plan CAL OES SUBMITTAL - JUNE 2026
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HMP Integration Notes / Additional Detail
Resource Status
Current
Mitigation
Use
Future
Opportunity
Hazard Reduction Programs
(Annually Conducted)
Capital Improvements Program
(CIP) or Plan Green Green Green
5-yr CIP maintained and implemented by Public
Works Dept; covers infrastructure upgrades and
hazard mitigation improvements
Erosion/Sediment Control
Program Green Green Green Ch 13.32 Stormwater and Runoff Pollution Control Hazard-Related Public Outreach
Program Green Green Green Water Conservation and Rebate Programs; general hazard outreach and education
Urban Water Management Plan Green Green Green Water Management Plan Ordinance Stormwater Management
Program (Annual Inspections) Green Green Green Stormwater Management Program implemented by Public Works Dept
Seismic Safety Program (Nonstructural) Yellow Yellow Green General seismic safety information on Disaster Preparedness webpage
Earthquake Modernization Plan
(Building Safety) Green Green Green Ch 15.40 Retrofitting of Unreinforced Masonry Buildings
Hazard Plans
General Plan Safety Element
Green Green Green
2040 General Plan Public Health, Safety, and Noise
Element covers flood, fire, geologic, and seismic
hazards
Site Plan Review Requirements Green Green Green Major and Minor Design Reviews General Plan Environmental
Justice Element Yellow Yellow Green No standalone element; integrated into various 2040 General Plan elements
Community Wildfire Protection
Plan (CWPP) Green Green Green 2021 Napa County CWPP
Economic Development Plan Yellow Yellow Yellow 2040 General Plan Economic Sustainability Element
Floodplain Management Plan Green Green Green 2040 General Plan Public Health, Safety, and Noise Element
Stormwater Management Plan Green Green Green Stormwater Master Plan Emergency Operations Plan Green Green Green 2017 Napa County EOP, City of St. Helena Annex; Evacuation Study
Climate Action Plan
Green Green Green
2040 General Plan Climate Change Element; Napa
County Regional Climate Action and Adaptation
Plan (RCAAP)
Climate Vulnerability
Assessment Green Green Green
2023 Climate Change Hazards and Vulnerability
Assessment included in General Plan Safety
Element; Napa County RCAAP includes regional
assessment
Urban Greening Plan Green Green Green 2040 General Plan Open Space and Conservation and Climate Change Elements
Ground Water Management
Planning / Plans Green Green Green
Maintained by Napa County Groundwater
Sustainability Agency; Water Management Plan
Ordinance governs City water use
National Flood Protection
Program (NFIP)
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HMP Integration Notes / Additional Detail
Resource Status
Current
Mitigation
Use
Future
Opportunity
Floodplain Management
Regulations Green Green Green Ch 15.52 Flood Damage Prevention in compliance with minimum NFIP requirements
Flood Insurance Education and
Technical Assist. Yellow Yellow Green
General flood hazard guidance provided on Disaster
Preparedness webpage; no insurance information;
general technical assistance available
Flood Insurance Study Green Green Green 2016 FEMA FIS 06055CV000C Elevation Certificates Green Green Green Maintained by Community Development Dept, Building Division
Flood Hazard Mapping / ReMapping Green Green Green FEMA FIRMs 2008-2016 Community Rating System (CRS) Orange Orange Yellow Does not currently participate; future opportunity but limited staff capacity
Administrative and
Technical
Community Planning and
Development Services
Community Planner Green Green Green Community Development Dept, Planning Division Planner/Engineer (Land
Development) Yellow Yellow Green No dedicated staff; shared role in Public Works Dept, Engineering Division
Engineer/Professional
(Construction) Green Green Green Public Works Dept, Engineering Division Planner/Engineer/Scientist
(Natural Hazards) Green Green Green Public Works Dept, Engineering Division Transportation Planner Yellow Yellow Green No dedicated staff; shared role in Public Works Dept, Engineering Division
Resiliency Planner Yellow Yellow Green No dedicated staff; shared across departments and provided by consultants
Building Code Official (Full time
or Augmented) Green Green Green Community Development Dept, Building Division Floodplain Administrator Green Green Green City Engineer Fire Marshal Green Green Green City of St. Helena Fire Chief Dedicated Public Outreach
Personnel Yellow Yellow Green No dedicated staff; shared across departments and supported by County
GIS Specialist and Capability Yellow Yellow Green No dedicated staff; provided by Napa County GIS and consultants
Emergency Manager Yellow Yellow Green No dedicated position; functions coordinated with Napa County OES
Dedicated Grant Manager, Writer,
or Specialist Yellow Yellow Green
No dedicated staff; reliance on consultants or
regional agencies for grant preparation and
administration
Other N/A N/A N/A
Warning Systems/Services
General Green Green Green ALERT Napa County system and Hi-Lo sirens CAL OES SUBMITTAL - JUNE 2026
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HMP Integration Notes / Additional Detail
Resource Status
Current
Mitigation
Use
Future
Opportunity
Flood Green Green Green ALERT Napa County system and Hi-Lo sirens Tornado Green Green Green ALERT Napa County system and Hi-Lo sirens Wildfire Green Green Green ALERT Napa County system and Hi-Lo sirens Geological Hazards Green Green Green ALERT Napa County system and Hi-Lo sirens Fiscal Capabilities
Financial Resources for
Hazard Mitigation
Levy Taxes for Specific Purposes
Yellow Yellow Yellow
Not consistently applied, but can place special tax
measures on ballot for specific purposes (e.g., sales
tax for public safety)
Utilities Fees Green Green Green Water and sewer tap and service fees Benefit assessments Orange Orange Yellow Not currently in use Community Development Block
Grants Yellow Yellow Green Received via HUD; can support hazard-related housing rehabilitation and infrastructure
System Development Fee
Green Green Green
Development and impact fees for public safety,
civic improvements, water, sewer, storm drainage,
traffic, housing, and school district
General Obligation Bonds to
Incur Debt Orange Orange Green Not currently used, but available financing tools Special Tax Bonds to Incur Debt Orange Orange Green Not currently used, but authorized for specific projects
Withheld Spending in HazardProne Areas Green Green Green General Plan policies restrict development in hazard-prone areas
Stormwater Service Fees Green Green Green Plan review and insepction fees; storm drainage impact fee
Capital Improvement Project
Funding Green Green Green CIP adopted; tied to annual budget Education / Outreach
Capabilities
Education/Outreach
Resources
Website Dedicated to Hazard
Topics Green Green Green
Disaster Preparedness webpage under Office of the
City Manager provide information on fire, flood,
earthquake, and other hazards
Dedicated Social Media Green Green Green Active Facebook, Instagram, Threads, Twitter (X), Nextdoor, LinkedIn, and YouTube accounts
Local Citizen Groups That
Communicate Hazard Risks Green Green Green
Informal local groups and neighborhood
associations provide hazard information (e.g., Napa
Valley COAD)
Hazard Info. Avail. at Library/
Planning Desk Yellow Yellow Green Limited use; mostly web-based Annual Public Safety Events Green Green Green Participates in Earthquake ShakeOut, Ready Napa County, and other regular events
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HMP Integration Notes / Additional Detail
Resource Status
Current
Mitigation
Use
Future
Opportunity
Ability to Field Public Tech.

Assistance Requests Green Green Green
Staff respond to inquiries via phone, email, and web
forms; department-specific technical assistance
available
Public Safety Newsletters or
Printed Outreach Yellow Yellow Green Not used consistently; mostly web-based Community Emergency
Response Team (CERT) Yellow Yellow Green Napa County CERT Fire Safe Councils Yellow Yellow Green Fire Safe Council and others through Napa Communities Firesafe Foundation
Firewise Orange Orange Green Not currently designated
StormReady Orange Orange Green Not currently designated Resource Conservation Districts
Green Green Green
Napa County RCD provides outreach on wildfire,
drought, and other hazard topics; City participates
through partnerships
Other N/A N/A N/A
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4.6.2 City of St. Helena Mitigation Action
St. Helena’s mitigation
actions were developed
through a collaborative
process informed by the
updated risk
assessment, local
priorities, and extensive
stakeholder
engagement. As part of
this 2026 MJHMP
update, the city
reviewed mitigation
actions from its prior
Local Hazard Mitigation
Plan to determine which
actions to carry forward,
which to consolidate,
and where entirely new
strategies were required.

This careful evaluation
ensured that the
updated action plan builds upon past commitments while also responding to current risks and future challenges.

The plan addresses St. Helena’s most significant hazards, including wildfire, earthquake, flood, slope failure, drought, dam failure, and extreme weather. Each mitigation action is designed to align with FEMA’s hazard mitigation guidance and the requirements of the Disaster Mitigation Act of 2000. Where appropriate, overlapping or redundant actions were consolidated into broader, more comprehensive strategies that improve clarity, increase feasibility, and strengthen regional coordination.

The mitigation action prioritization method used by all participating jurisdictions is described in Volume 1, Section 4. Each action specific to St. Helena is documented in Table 4-17, which identifies the responsible department, implementation timeframe, potential funding sources, and resources required to complete the action. Each action is also assigned a unique alphanumeric identifier (see Figure 4-20) that links the strategy to its associated hazard and supports consistent monitoring and reporting.

St. Helena’s approach recognizes that some hazards are most effectively addressed through regional efforts.

Flood protection, drought resilience, and wildfire risk reduction often extend beyond the city’s boundaries and require collaboration with county, regional, and state partners. By aligning local actions with regional Figure 4-20: Mitigation Action Number Key
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strategies, St. Helena helps to consolidate resources, maximize funding opportunities, and ensure that mitigation projects achieve the greatest benefit for the Napa Valley and the wider Napa County community.

Collectively, these mitigation actions provide a roadmap for reducing hazard risk, protecting vulnerable populations, and strengthening the long-term resilience of St. Helena.

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Table 4-17: City of St. Helena Mitigation Action Plan
Mitigation No. Hazard
Type
SubHazardMitigation
Type
Year Primary
Agency
Title Description Responsible
Party
Estimated
Cost
Estimated
Benefit
Time
Frame
HMA
Activity
Type
Potential Grant
Source
Priority Related Problem Statements
ma-AH-SH-7 All Hazard PE&A - Public
Education &
Awareness
2020 City of St.

Helena
Emergency
Preparedness
Awareness
Campaign
Update, improve, and maintain multi-hazard
emergency preparedness information on the
City website, social media accounts, and
newsletters, including outreach on evacuation
route and shelter information targeted to
tourists through lodging operators.

City Manager's
Office
Low Medium 1-3 Years Capacity /
Capability
Building

HMGP / BRIC ,
General Fund
High ps-WF-SH-189, ps-WF-SH-190,
ps-WF-SH-193, ps-FL-SH-136,
ps-FL-SH-133, ps-FL-SH-132,
ps-EQ-SH-88, ps-EQ-SH-87,
ps-CC-SH-329, ps-DR-SH-331,
ps-EQ-SH-68, ps-EQ-SH-86,
ps-FL-SH-112, ps-FL-SH-118,
ps-FL-SH-131, ps-SW-SH-334,
ps-SW-SH-335, ps-WF-SH-186,
ps-WF-SH-192
ma-AH-SH-8 All Hazard ES -
Emergency
Services , SP -
Structural
Projects
2020 City of St.

Helena
Critical
Facility
Power
Resilience
Projects
Assess, plan for, and implement microgrids and
backup power systems at key facilities (EOC, fire
station, police, water/wastewater, designated
shelters) to maintain operations during and after
hazard events.

Public Works
Department
High High 3-5 Years Project HMGP / BRIC ,
General Fund
High ps-WF-SH-191, ps-EQ-SH-90,
ps-CC-SH-329, ps-EQ-SH-331,
ps-EQ-SH-68, ps-EQ-SH-86,
ps-SW-SH-334, ps-SW-SH-335,
ps-WF-SH-186, ps-EH-SH-399,
ps-EH-SH-397
ma-AH-SH-9 All Hazard PE&A - Public
Education &
Awareness
2020 City of St.

Helena
All-Hazard
Mitigation
Education
Program
Develop an outreach and education program
that provides guidance on home, business, and
public facility hazard mitigation, financial
resources, and available technical assistance.

Host annual workshops supported by free or
low-cost resource kits, including on hazard
insurance, earthquake risk and retrofits, wildfire
structural hardening and defensible space,
human-caused ignition, air quality mitigation
measures, flood protection, drainage
improvements, and slope failure prevention.

This includes workshops targeted for
homeowners, renters, mobile home occupants,
small businesses, adult and child care providers,
and schools and other assembly facilities.

City Manager's
Office
Low High 1-3 Years Capacity /
Capability
Building

HMGP / BRIC ,
General Fund
High ps-FL-SH-134, ps-EQ-SH-89,
ps-CC-SH-329, ps-DR-SH-331,
ps-EQ-SH-68, ps-EQ-SH-86,
ps-SW-SH-334, ps-SW-SH-335,
ps-WF-SH-186, ps-EH-SH-398,
ps-EH-SH-397
ma-DF-SH-222 Dam
Failure
PRV -
Prevention ,
PE&A - Public
Education &
Awareness
2026 City of St.

Helena
Dam Failure
Evacuation
Planning &
Awareness
Campaign
In coordination with dam owners and operators,
update emergency evacuation procedures to
address vulnerable neighborhoods, tourist areas,
and high occupancy facilities, including
improved warning systems. Conduct regular
awareness campaigns to increase community
understanding of risks and evacuation,
including through targeted outreach and
installing signage in areas of inundation.

Planning
Department
Low Medium 3-5 Years Capacity /
Capability
Building

HMGP / BRIC ,
General Fund
Medium ps-DF-SH-27, ps-DF-SH-330
ma-DR-SH-29 Drought PRV -
Prevention ,
NRP - Natural
Resource
Protection
2020 City of St.

Helena
WaterEfficient
Landscaping
Assistance
Program
Develop model planting plans, design guidance,
and incentives to help residents and businesses
shift to water-smart landscaping consistent with
water-conservation policies.

Planning
Department
Low Medium 1-3 Years Project HMGP / BRIC ,
General Fund
High ps-DR-SH-54, ps-CC-SH-329,
ps-DR-SH-331
ma-FL-SH-71 Flood NRP - Natural
Resource
Protection , SP
- Structural
Projects
2020 City of St.

Helena
Drainage
Improvement
Projects
Improve stormwater conveyance capacity,
debris control, slope stabilization, and
maintenance practices to reduce localized
flooding at key locations such as the Pratt
Avenue and Pope Street bridges. Implement
nature-based drainage solutions where feasible.

Public Works
Department
High High 5-10 Years Project HMGP / BRIC ,
FMA , General
Fund
Medium ps-FL-SH-135, ps-CC-SH-329,
ps-DF-SH-27, ps-DF-SH-330,
ps-EQ-SH-331, ps-FL-SH-112,
ps-FL-SH-118, ps-FL-SH-131,
ps-SW-SH-334, ps-SW-SH-335,
ps-SF-SH-332, ps-SF-SH-333
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Mitigation No. Hazard
Type
SubHazardMitigation
Type
Year Primary
Agency
Title Description Responsible
Party
Estimated
Cost
Estimated
Benefit
Time
Frame
HMA
Activity
Type
Potential Grant
Source
Priority Related Problem Statements
ma-SF-SH-223 Slope
Failure
PRV -
Prevention
2026 City of St.

Helena
Slope
Stability
Assessment
Identify and assess high-risk slopes and
incorporate any needed improvements into the
CIP for stabilization, stormwater management,
erosion control, or other mitigation measures.

Public Works
Department
Low Low 1-3 Years Project HMGP / BRIC ,
General Fund
Medium ps-SF-SH-332, ps-SF-SH-333
ma-WF-SH-103 Wildfire PPRO -
Property
Protection ,
NRP - Natural
Resource
Protection
2020 City of St.

Helena
Fuel
Management
& Critical
Facility
Hardening
Projects
Conduct vegetation management and structural
hardening projects for City properties and
critical facilities, including in parks, on open
space, along transportation routes, around
schools and other facilities, and on adjacent
private lands with landowner coordination.

Implement air quality mitigation measures for
shelters, schools, and other facilities.

Fire Department High High 3-5 Years Project HMGP / BRIC , General Fund ,
CalFIRE
High ps-WF-SH-186, ps-WF-SH-192,
ps-WF-SH-193, ps-CC-SH-329,
ps-WF-SH-192, ps-WF-SH-197
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4.6.3 Status of Previous Mitigation Actions
In 2020, the City of St. Helena adopted its previous FEMA-approved HMP. This 2026 MJHMP represents a comprehensive update from that previous plan, as discussed in Volume 1, Section 1.5. Table 4-18 provides status updates for all of the previous mitigation actions in the City of St. Helena HMP, from which many of the mitigation actions in Table 4-17 were sourced and revised.

Table 4-18: City of St. Helena Status of Previous Mitigation Actions Mitigation
No.

Hazard
Type
Status Year Primary
Agency
Title/Description Reason Cancelled/
Completed
ma-AH-SH-7 All Hazard Ongoing 2020 City of St.

Helena
Emergency
Preparedness
Awareness Campaign
Revised
ma-AH-SH-8 All Hazard Ongoing 2020 City of St.

Helena
Critical Facility Power
Resilience Projects
Revised
ma-AH-SH-9 All Hazard Ongoing 2020 City of St.

Helena
All-Hazard Mitigation
Education Program
Revised
ma-DR-SH-29 Drought Ongoing 2020 City of St.

Helena
Water-Efficient
Landscaping Assistance
Program
Revised
ma-FL-SH-71 Flood Ongoing 2020 City of St.

Helena
Drainage Improvement
Projects
Revised
ma-WF-SH-103 Wildfire Ongoing 2020 City of St.

Helena
Fuel Management &
Critical Facility
Hardening Projects
Revised
ma-DR-SH-30 Drought Cancelled 2020 City of St.

Helena
During drought
conditions increase fuel
reduction in parks and
open space areas.

SH-16-2020, SH-02-2020, SH-03-
2020 & SH-09-2020 combined and
revised
ma-EQ-SH-44 Earthquake Cancelled 2020 City of St.

Helena
Develop earthquake
mitigation resource kits
for St. Helena residents,
with focused outreach
for adult care providers,
private schools, and
gathering facilities.

SH-12-2020, SH-14-2020, SH-05-
2020, SH-01-2020, SH-04-2020,
SH-08-2020 & SH-10-2020
combined and revised
ma-FL-SH-69 Flood Cancelled 2020 City of St.

Helena
Provide Napa River
residents with flood
protection resources,
including technical
support, education, and
grant assistance for
floodproofing.

SH-12-2020, SH-14-2020, SH-05-
2020, SH-01-2020, SH-04-2020,
SH-08-2020 & SH-10-2020
combined and revised
ma-FL-SH-70 Flood Cancelled 2020 City of St.

Helena
Provide flood mitigation
resources to residents
within the Vineyard
Valley Mobile Home
Park.

SH-12-2020, SH-14-2020, SH-05-
2020, SH-01-2020, SH-04-2020,
SH-08-2020 & SH-10-2020
combined and revised
ma-WF-SH-104 Wildfire Cancelled 2020 City of St.

Helena
Implement fuel
reduction projects to
reduce impacts to homes
and businesses.

SH-16-2020, SH-02-2020, SH-03-
2020 & SH-09-2020 combined and
revised
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Mitigation
No.

Hazard
Type
Status Year Primary
Agency
Title/Description Reason Cancelled/
Completed
ma-WF-SH-105 Wildfire Cancelled 2020 City of St.

Helena
Retrofit At-Risk
Structures with IgnitionResistant Materials or
Require or Encourage
Fire-Resistant
Construction
Techniques.

SH-12-2020, SH-14-2020, SH-05-
2020, SH-01-2020, SH-04-2020,
SH-08-2020 & SH-10-2020
combined and revised
ma-WF-SH-106 Wildfire Cancelled 2020 City of St.

Helena
Develop and or share
outreach material on air
quality mitigation
measures for residents
before wildfire season.

SH-12-2020, SH-14-2020, SH-05-
2020, SH-01-2020, SH-04-2020,
SH-08-2020 & SH-10-2020
consolidated and revised
ma-WF-SH-107 Wildfire Cancelled 2020 City of St.

Helena
Implement fuel
reduction/building
retrofit projects to limit
combustibility to school
facilities.

SH-16-2020, SH-02-2020, SH-03-
2020 & SH-09-2020 combined and
revised
ma-WF-SH-108 Wildfire Cancelled 2020 City of St.

Helena
Develop Public
awareness information
for wildfire season
related to
flame/sparking
equipment.

SH-12-2020, SH-14-2020, SH-05-
2020, SH-01-2020, SH-04-2020,
SH-08-2020 & SH-10-2020
consolidated and revised
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Section 5. Town of Yountville
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2026 Multi-Jurisdictional Hazard Mitigation Plan Update Town of Yountville (YT)
Municipal Annex
vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvSection 5......Town of Yountville 5-9

5.1 Scope & Purpose .....................................................................................................................................................................5-9

5.2 Jurisdictional Setting...........................................................................................................................................................5-9

5.2.1 Geography & Climate ................................................................................................................................................ 5-10

5.2.2 Demographics & Vulnerable Populations......................................................................................................... 5-12

5.2.3 Economy........................................................................................................................................................................5-28

5.2.4 Growth Trends & Future Development..............................................................................................................5-28

5.3 Planning Process .................................................................................................................................................................5-29

5.3.1 Public Input & Draft Review ................................................................................................................................... 5-31

5.4 What’s New.............................................................................................................................................................................5-32

5.4.1 Mitigation Activities .................................................................................................................................................5-32

5.4.2 Mitigation Successes................................................................................................................................................5-33

5.5 Risk Assessment..................................................................................................................................................................5-34

5.5.1 Hazard Screening & Prioritization ......................................................................................................................5-34

5.5.2 Vulnerability to Specific Hazards........................................................................................................................5-38

5.5.3 Climate Change Impacts & Vulnerable Populations....................................................................................5-57

5.5.4 Hazard Problem Statements..................................................................................................................................5-58

5.6 Mitigation Strategy ............................................................................................................................................................. 5-61

5.6.1 Capabilities & Opportunities..................................................................................................................................5-62

5.6.2 Town of Yountville Mitigation Action Plan.....................................................................................................5-75

5.6.3 Status of Previous Mitigation Actions...............................................................................................................5-79 CAL OES SUBMITTAL - JUNE 2026
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List of Figures
Figure 5-1: Town of Yountville Geographic Overview Map ..............................................................................................5-11 Figure 5-2: Town of Yountville Median Household Income Map.................................................................................. 5-15 Figure 5-3: Town of Yountville Poverty Status Map........................................................................................................... 5-16 Figure 5-4: Town of Yountville Housing Occupancy Map ............................................................................................... 5-17 Figure 5-5: Town of Yountville Dependent Age Groups Map.......................................................................................... 5-21 Figure 5-6: Town of Yountville Disabled Elderly Map .......................................................................................................5-22 Figure 5-7: Town of Yountville Race and Ethnicity Map................................................................................................. 5-24 Figure 5-8: Town of Yountville Spanish-Speaking Households Map..........................................................................5-25 Figure 5-9: Town of Yountville CDC Social Vulnerability Index Map..........................................................................5-27 Figure 5-10: Town of Yountville Risk Assessment Matrix...............................................................................................5-36 Figure 5-11: Exposure Summary – Yountville Wildfire Risk.......................................................................................... 5-40 Figure 5-12: Exposure Summary – Yountville Earthquake Risk (M7.1 Hunting Creek–Berryessa)............... 5-43 Figure 5-13: Exposure Summary – Yountville Earthquake Risk (M6.7 West Napa).............................................. 5-44 Figure 5-14: Exposure Summary – Yountville Liquefaction Risk.................................................................................5-45 Figure 5-15: Exposure Summary –Yountville Flood Risk (FEMA Zones).................................................................. 5-48 Figure 5-16: Drought Severity Timeline 2000-2024.............................................................................................................5-52 Figure 5-17: Exposure Summary – Yountville Dam Inundation Zone ........................................................................5-54 Figure 5-18: Mitigation Action Number Key ..........................................................................................................................5-75 CAL OES SUBMITTAL - JUNE 2026
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List of Tables
Table 5-1: Town of Yountville Population and Households............................................................................................. 5-12 Table 5-2: Town fo Yountville Income and Poverty............................................................................................................ 5-13 Table 5-3: Town of Yountville Renter- and Owner-Occupied Housing ......................................................................5-14 Table 5-4: Town of Yountville Households with Seniors ................................................................................................. 5-18 Table 5-5: Town of Yountville Households with Children ...............................................................................................5-19 Table 5-6: Town of Yountville Population with Disabilities and Access to Transportation.............................. 5-20 Table 5-7: Town of Yountville Household Languages .......................................................................................................5-23 Table 5-8: Town of Yountville Planning Team and Steering Group Members ........................................................5-30 Table 5-9: Town of Yountville Planning Team Meetings ................................................................................................. 5-31 Table 5-10: Town of Yountville Document Review of Potential Hazards...................................................................5-35 Table 5-11: Town of Yountville Hazards Prioritization Summary.................................................................................5-37 Table 5-12: Town of Yountville National Flood Insurance Program Information.................................................. 5-47 Table 5-13: Drought Classifications and Impacts.................................................................................................................5-50 Table 5-14: Town of Yountville Hazard Problem Statements .........................................................................................5-58 Table 5-15: Town of Yountville Capabilities and Opportunities Assessment ......................................................... 5-70 Table 5-16: Town of Yountville Mitigation Action Plan.....................................................................................................5-77 Table 5-17: Town of Yountville Status of Previous Mitigation Actions.......................................................................5-79 CAL OES SUBMITTAL - JUNE 2026
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Adoption Resolution
To comply with the Federal Disaster Mitigation Act of 2000 (DMA 2000), the Yountville Town Council has officially adopted this 2026 Napa County Multi-Jurisdictional Hazard Mitigation Plan, including Volume 1 in its entirety as well as this Volume 2 municipal annex. The adoption of the MJHMP recognizes the town’s commitment to reducing the impacts of natural hazards within its jurisdiction and across Napa County.

A copy of the town’s adoption record is provided on the following pages. Adoption records for all jurisdictions are summarized in Volume 1, Table ES-1.

ADOPTION RECORD TO BE INSERTED UPON COMPLETION.

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Section 5.Town of Yountville

5.1 Scope & Purpose
This Jurisdictional Annex for the Town of Yountville of the 2026 Napa County Multi-Jurisdictional Hazard Mitigation Plan (MJHMP) details the hazard mitigation planning
elements specific to the town’s planning area. The annex is not intended to be a standalone document but appends to and supplements the information contained in the umbrella plan document (Volume 1). As such, all sections of the umbrella plan, including the planning process and other procedural requirements, apply to and were met by the Town of Yountville. This annex provides additional information specific to the Town, with a focus on hazard identification and risk assessment, vulnerability assessment, problem statements, mitigation strategy, and capabilities assessment. Below are the Town of Yountville Points of Contact:

Primary Point of Contact Alternate Point of Contact
Hilary Gaede, Communications Director / Town Clerk
Town of Yountville
6550 Yount Street
Yountville, CA 94599
Telephone: (707) 944-8851
email: [email protected]
John Ferons, Public Works Director
Town of Yountville
6550 Yount Street
Yountville, CA 94599
Telephone: (707) 944-8851
email: [email protected]

5.2 Jurisdictional Setting
The Town of Yountville sits in the heart of the Napa Valley in Napa County in Northern California, approximately 40 miles north of San Francisco. The town is bounded by the Mayacamas Mountains to the west, the Napa Valley to the south and north, and the Napa River to the east. The Town is situated along Highway 29, which provides regional access to other parts of Napa County. Yountville is a small town best known for the Veteran’s Home of California, Yountville, fine-dining establishments, and upscale resorts.

Yountville encompasses approximately 1.5 square miles, mostly on the Napa Valley floor. The Napa River meanders east of the town limits. The western portion of the town limits contains the Veteran’s Home, a golf club, and winery, and edges up against the Mayacamas Mountains. This varied topography and semiproximity to a major waterway influences the Town’s exposure to natural hazards, including flooding, seismic shaking, wildfire along the wildland–urban interface, and climate change–related impacts such as extreme heat and increased flood risk.

The Town operates as a general law municipality under a council–manager form of government and provides a full range of municipal services, including public works, planning and building, and water, wastewater, and recycled water services. The Town contracts with the Napa County Sheriff's Department CAL OES SUBMITTAL - JUNE 2026
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for police protection and the Napa County Fire Department/CALFIRE for fire protection and emergency medical services.

The Town of Yountville’s location within Napa County is shown in Figure 5-1. ▪ Year of Incorporation: 1965
▪ 2021 Population: 3,397 (US Census Bureau, 2021)
▪ Population Growth: Low-to-Moderate

5.2.1 Geography & Climate
The Town of Yountville is located in the Napa Valley at the base of the Mayacamas Mountains. The town is located west of the Napa River. Figure 5-1 provides geographic overview of Napa County. Hydrologically, Yountville is part of the Napa River watershed, which conveys runoff from northern Napa County through the town before discharging into San Pablo Bay. Portions of the town lie near or within historic floodplain areas, particularly adjacent to the Napa River. These low-lying areas are subject to flooding. Stormwater systems throughout the town are designed to manage runoff generated by seasonal precipitation.

The climate in Yountville and the Napa Valley is warmer than that in the rest of the Bay Area. Nevertheless, in summer, Yountville and the rest of the Napa Valley are protected from the hot weather of the Central Valley of California by the coastal mountain ranges. The Pacific Ocean provides a source of cool, moist air in the summer, and this steady flow of marine air holds temperatures at a moderate level. The greatest variation in temperature occurs in summer. In Yountville, average high summer temperatures are in the upper 80's to the mid 90's. Winters are generally mild, but there are occasional cold spells. Average high winter temperatures are in the high 50's to low 60's, while the minimum temperatures are in the upper 20's and 30's. Frost is common during clear, calm mornings in the late fall and winter.

The growing season, which is the period between the last freezing temperature event in spring and the first in fall, ranges from 215 to 260 days in Yountville. Most of the annual precipitation falls during the period of November through April. The greatest amount of rainfall in one hour is expected to range from 0.9 inch in one hour once in two years to 2.1 inches in one hour once in 100 years.

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Figure 5-1: Town of Yountville Geographic Overview Map
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5.2.2 Demographics & Vulnerable Populations
This section describes the demographic characteristics of the Town of Yountville to guide hazard mitigation planning efforts. Natural disasters affect communities both physically and socially, with demographic composition playing a central role in determining how impacts are distributed, particularly among vulnerable groups facing greater challenges in preparedness, response, and recovery. Understanding the area's social and economic landscape also helps assess potential social costs from infrastructure damage, including housing, industry, public facilities, essential services, and transportation.

Exploring local demographic data may help to identify groups and geographic areas with specific vulnerability to hazard events. In the context of all-hazards preparedness and response planning, at-risk individuals (often used interchangeably with “vulnerable populations”) are defined federally as “children, pregnant women, senior citizens, and other individuals who have access or functional needs in the event of a public health emergency.” (42 U.S.C. § 2802(b)(4)(B) (2019)) These populations may include, but are not limited to, individuals who are economically disadvantaged, living with disabilities, dependent on caregivers, from historically marginalized communities, have limited English proficiency or are nonEnglish speaking, lack access to transportation, are experiencing homelessness, or have chronic medical conditions.

Certain populations face greater risk following a natural hazard event due to age, economic mobility, physical disability, geographic location, or a combination of factors. Vulnerability in the face of a hazard event is not a fixed characteristic; the same individual may be at risk for some hazards but not at risk for others. Planning for vulnerable populations in the context of hazard mitigation can help communities to prioritize limited resources where they will be the most effective. Refer to Volume 1, Section 1.4.3, for a more in-depth discussion of planning for vulnerable populations, at-risk individuals with access and functional needs, and environmental justice.

The total population, total number of households, and average household size of the Town of Yountville are presented in Table 5-1, compared to the other municipalities and Napa County. As shown in the table, Yountville is the smallest incorporated community in Napa County.

Table 5-1: Town of Yountville Population and Households Area Total Population Total Households (HH) Average HH Size Napa County 137,384 55,588 2.40
City of Napa 79,233 31,666 2.47
City of American Canyon 21,669 5,924 3.64
City of Calistoga 5,191 2,330 2.20
City of St. Helena 5,426 2,963 1.81
Town of Yountville 3,397 1,824 1.45
Source: ACS 5-Year, 2017-2022
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Income & Housing
Economic mobility is one of the most important predictors of natural hazard vulnerability. Low-income residents are more likely to occupy housing which is inadequately maintained or otherwise poorly built to withstand extreme events. For example, mobile or modular homes are more susceptible to damage in earthquakes and floods than other types of residences and are less likely to contain air conditioning units to cope with high heat events. In urban areas, low-income residents are more likely to occupy older homes and apartment complexes with unreinforced masonry, which is particularly susceptible to seismic damage.

Low-income households and communities face disproportionate financial burden from costs associated with disaster preparedness, response, and recovery. Disasters create unexpected expenses which may serve as “tipping points” for families and individuals living on the edge of poverty or homelessness. Recovery costs may be higher for those without resources to conduct hazard mitigation activities ahead of time. Families and individuals who lack access to transportation may be unable to evacuate ahead of an emergency. (Krause & Reeves, 2017)
Low-income residents and renters are also less likely to purchase insurance, meaning that those with the most to lose during an event are also the least prepared to deal with potential losses. Major hurricane events in recent history such as Harvey, Irma, and Katrina all demonstrate that low-income and/or historically marginalized communities face increased vulnerability to hazard events and struggle the most to recover.

Median household income in the Town of Yountville was approximately $75,134, with an overall poverty rate of around 11%. By comparison, median income and poverty rates for Napa County were nearly $106,000 and 8%, respectively; refer to Table 5-2. Median income and poverty rates are also shown on the block group level in Figure 5-2 and Figure 5-3.

Table 5-2: Town fo Yountville Income and Poverty
Area Median Income Poverty Rate
Napa County $105,809 7.9%
City of Napa $100,273 8.1%
City of American Canyon $122,694 7.4%
City of Calistoga $96,667 5.4%
City of St. Helena $135,781 5.7%
Town of Yountville $75,134 10.6%
Source: ACS 5-Year, 2017-2022
Renters are also more vulnerable to natural hazards, as they are less likely to take out property insurance and the decision to make major structural improvements typically lies with the property owner. Federal disaster recovery services can exacerbate inequality between renters and homeowners; payout amounts are significantly higher for homeowners applying through FEMA’s Individual Assistance (IA) program; from 1999 to 2013 U.S. homeowners saw their wealth increase with local hazard damages, whereas renters’ wealth decreased. (Howell, Junia; Elliot, James, 2019)
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Approximately 34.5% of occupied housing units in the Town of Yountville are renters, compared to approximately 35% for Napa County as a whole; refer to Table 5-3.

Table 5-3: Town of Yountville Renter- and Owner-Occupied Housing Jurisdiction # Occupied
Housing Units
# Renter
Occupied % Renter Occupied # Owner Occupied
% Owner
Occupied
Napa County 49,738 17,676 35.5% 32,062 64.5%
City of Napa 26,978 10,616 39.4% 16,362 60.6%
City of American Canyon 6,192 1,371 22.1% 4,821 77.9%
City of Calistoga 2,042 822 40.3% 1,220 59.7%
City of St. Helena 2,380 1,048 44% 1,332 56.0%
Town of Yountville 1,050 362 34.5% 688 65.5%
Source: ACS 5-Year, 2017-2022
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Figure 5-2: Town of Yountville Median Household Income Map CAL OES SUBMITTAL - JUNE 2026
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Figure 5-3: Town of Yountville Poverty Status Map
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Figure 5-4: Town of Yountville Housing Occupancy Map
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Dependent & Disabled Populations
Age is a significant factor in assessing vulnerability to natural hazards. Both older adults and children are considered dependent populations due to their reliance on caregivers for safety, mobility, and support during emergency events. These populations face heightened risks during disasters such as floods, wildfires, and earthquakes, particularly when compounding factors such as poverty, disability, or social isolation are present.

In the Town of Yountville, approximately 48% of households include at least one individual over the age of 65, and over 19% of all households consist of seniors living alone. While only around 4% of senior households live below the poverty line (Table 5-4), seniors, particularly those who are low-income or socially isolated, remain among the most vulnerable populations in disaster situations. Challenges for older adults may include limited mobility, chronic health conditions, reduced digital literacy, and lack of access to real-time emergency alerts. Seniors living alone may require additional assistance during evacuations or power outages, and assisted living facilities necessitate advanced coordination to ensure continuity of care and safety during emergencies.

Children represent another dependent population requiring special consideration (Table 5-5). In Yountville, nearly 9% of households include individuals under the age of 18, with zero of these households headed by a single caregiver. During emergencies, children are entirely dependent on caregivers for decision-making, transportation, and access to essential resources. Disruptions to schools, childcare, and youth services can result in significant emotional, educational, and developmental impacts. Families with limited means or single caregivers may also face greater challenges in securing housing, supplies, and recovery assistance.

Figure 5-5 highlights areas within Yountville with higher concentrations of economically dependent age groups, informing targeted outreach and response strategies during emergencies.

Table 5-4: Town of Yountville Households with Seniors
Jurisdiction Households (HH) 65+ % 65+ Alone %
65+
Poverty %
Napa County 55,588 18,777 33.8% 4,816 8.7% 1,271 2.3%
City of American Canyon 5,924 1,772 29.9% 184 3.1% 111 1.9% City of Calistoga 2,330 1,003 43.0% 419 18.0% 101 4.3%
City of Napa 31,666 10,299 32.5% 2,674 8.4% 703 2.2%
City of St. Helena 2,963 1,153 38.9% 296 10.0% 42 1.4%
Town of Yountville 1,824 873 47.9% 351 19.2% 77 4.2%
Source: ACS 5-Year, 2017-2022
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Table 5-5: Town of Yountville Households with Children
Jurisdiction Households <18 %
<18 Single
Caregiver %
Napa County 55,588 14,596 26.3% 3,109 5.6%
City of American Canyon 5,924 2,633 44.4% 417 7.0%
City of Calistoga 2,330 471 20.2% 33 1.4%
City of Napa 31,666 8,934 28.2% 2,315 7.3%
City of St. Helena 2,963 619 20.9% 168 5.7%
Town of Yountville 1,824 160 8.8% 0 0.0%
Source: ACS 5-Year, 2017-2022
Elderly populations face increased risks during disaster events due to age-related health conditions, mobility limitations, and potential social isolation. In Yountville, approximately 20% of the noninstitutionalized population lives with a disability, a substantially higher rate than the countywide average of 12% (Table 5-6).

Among those with access and functional needs, elderly individuals with disabilities represent a highly vulnerable subpopulation when it comes to disaster preparedness, response, and recovery. This group includes seniors living with physical or cognitive impairments such as hearing or vision loss, reduced mobility, reliance on assistive medical devices, neurodivergence, or chronic health conditions that may be exacerbated by hazard events (e.g., exposure to wildfire smoke or extreme heat).

Figure 5-6 illustrates that in some portions of the Town, more than 47% of the elderly population is estimated to have one or more disabilities, while other areas show lower proportions or lack available data. The spatial distribution shown on this map suggests that vulnerability is not uniform across the town and that certain neighborhoods may have greater needs for evacuation assistance, medical support, and continuity of care during emergencies. Seniors with disabilities may also be more sensitive to extended power outages, disruptions to medical services, and transportation interruptions. These risks are expected to increase under climate change conditions that intensify extreme heat events and strain emergency response resources.

The combination of advanced age and disability can present significant challenges not only during emergency response but also in implementing hazard mitigation measures. Elderly individuals with disabilities may face physical, financial, or logistical barriers to undertaking activities such as seismic retrofitting, anchoring fuel tanks, installing foundation bracing, or implementing residential flood-proofing techniques. Many live in older housing stock that is more vulnerable to earthquake damage or repetitive flooding and may lack the resources or support networks needed to complete mitigation upgrades.

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Table 5-6: Town of Yountville Population with Disabilities and Access to Transportation Jurisdiction Population
Persons
w/
Disability %
Persons
Reliant on
Public
Trans. % Households
HH w/o
Vehicle %
Napa County 137,384 16,544 12.0% 890 0.6% 55,588 2,421 4.4% City of American Canyon 21,669 2,201 10.2% 287 1.3% 5,924 138 2.3% City of Calistoga 5,191 573 11.0% 36 0.7% 2,330 83 3.6% City of Napa 79,233 9,837 12.4% 291 0.4% 31,666 1,554 4.9% City of St. Helena 5,426 683 12.6% 121 2.2% 2,963 219 7.4% Town of Yountville 3,397 683 20.1% 15 0.4% 1,824 210 11.5% Source: ACS 5-Year, 2017-2022
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Figure 5-5: Town of Yountville Dependent Age Groups Map CAL OES SUBMITTAL - JUNE 2026
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Figure 5-6: Town of Yountville Disabled Elderly Map
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Race, Ethnicity & Language
Natural disasters compound racial disparities; non-white individuals and communities receive less recovery aid from FEMA than their white counterparts, even where the amount of damage is the same. (Howell, Junia; Elliott, James R., 2019) (National Advisory Council, 2020) These disparities are evidence of the complicated relationship between disaster recovery and overlapping social vulnerabilities including race, income, language, and health. Black and Latino residents are more likely to be low income and renters, conditions which create barriers to navigating FEMA’s Individual Assistance programs. Communities with more non-white residents may have lower tax revenue and property values, which means less investment in mitigation and rebuilding efforts before and after an emergency.

Figure 5-7 depicts the racial and ethnic composition of the Town of Yountville. According to ACS data, the Town is mostly White, but also has a significant Hispanic or Latino population.

Residents with limited English proficiency (LEP) face heightened barriers to understanding emergency alerts, accessing preparedness resources, and navigating post-disaster recovery programs. In Yountville, approximately 3% of households speak Spanish and around 3% report limited English proficiency. (Table 5-7). Figure 5-8 highlights where Spanish-speaking populations are concentrated in Yountville.

Table 5-7: Town of Yountville Household Languages
Jurisdiction Households (HH) Spanish Speaking %
Limited
English %
Other
Lang. %
Napa County 55,588 8,738 15.7% 2,141 3.9% 12 0.0%
City of American Canyon 5,924 1,069 18.0% 177 3.0% - 0.0% City of Calistoga 2,330 474 20.3% 63 2.7% - 0.0%
City of Napa 31,666 5,800 18.3% 1,653 5.2% 9 0.0%
City of St. Helena 2,963 370 12.5% 88 3.0% - 0.0%
Town of Yountville 1,824 49 2.7% 21 1.2% - 0.0%
Source: ACS 5-Year, 2017-2022
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Figure 5-7: Town of Yountville Race and Ethnicity Map
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Figure 5-8: Town of Yountville Spanish-Speaking Households Map CAL OES SUBMITTAL - JUNE 2026
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Social Vulnerability Index (SVI)
The Centers for Disease Control and Prevention (CDC) Social Vulnerability Index (SVI) for Town of Yountville reveals important spatial and demographic patterns that have direct implications for equitable hazard mitigation planning. As discussed in detail in Volume 1, Section 1.4.3.6, the SVI is a composite measure developed by the CDC to identify communities that are more likely to require support before, during, and after a disaster. It incorporates a range of factors across four key dimensions: socioeconomic status, household composition and disability, minority status and language, and housing type and transportation access. The resulting index score ranges from 0 (lowest vulnerability) to 1 (highest vulnerability).

Figure 5-9 shows that social vulnerability ranges between 0.50 and 1.00 in Yountville, which is indicative of moderate to high SVI. Areas with higher SVI values indicate neighborhoods where residents may have reduced capacity to prepare for, respond to, and recover from hazard events due to factors such as lower income, higher proportions of renters, limited access to vehicles, language barriers, or greater concentrations of elderly and disabled individuals. Conversely, areas with lower SVI scores generally reflect populations with greater access to resources and adaptive capacity.

Spatial patterns in the SVI map suggest that higher social vulnerability is concentrated in portions of the central and southern areas of the town, where multiple vulnerability indicators overlap. These areas may experience disproportionate impacts during events such as flooding, extreme heat, earthquakes, or wildfire smoke episodes, particularly if hazards coincide with power outages, transportation disruptions, or prolonged recovery periods. Residents in higher-SVI neighborhoods may also face challenges accessing emergency information, evacuation assistance, sheltering, and post-disaster financial or housing resources.

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Figure 5-9: Town of Yountville CDC Social Vulnerability Index Map CAL OES SUBMITTAL - JUNE 2026
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5.2.3 Economy
The Town of Yountville plays a unique economic role within central Napa County. Although the Town is small, it does have a major employer—the Veteran’s Home of California, Yountville—and a significant visitor-serving commercial tax base. Notable visitor-serving businesses include The French Laundry and several upscale lodging establishments.

Retail, restaurants, and visitor-serving commercial uses are primarily concentrated on Washington Street.

These businesses contribute significantly to local tax revenues and provide jobs for residents of Yountville and surrounding communities. At the same time, the concentration of economic activity along Washington Street increases the importance of protecting critical infrastructure, transportation corridors, and utility systems from natural hazards such as flooding, earthquakes, and power outages.

The Town’s commercial economy includes neighborhood-serving retail, restaurants, and personal services that support daily needs and contribute to community vitality. These businesses are particularly sensitive to hazard-related disruptions, as temporary closures, infrastructure damage, or reduced access can result in lost income and longer-term economic impacts. Small businesses may have limited capacity to absorb prolonged disruptions, making economic resilience an important consideration in hazard mitigation planning.

A significant portion of Yountville’s workforce is employed in sectors that involve physical labor or outdoor activity, including agriculture and visitor-serving commercial uses. These workers may face heightened exposure to hazards such as extreme heat, wildfire smoke, and poor air quality. Climate change projections indicating more frequent heat events and longer wildfire seasons have implications for worker safety, productivity, and business continuity within these sectors.

Economic vulnerability is also influenced by income variability and employment stability. Workers in hourly or service-based positions may experience immediate income loss during disaster-related closures or evacuations, which can compound household vulnerability and slow community recovery. Protecting employment centers, maintaining transportation access, and ensuring continuity of utilities and communications are therefore key components of reducing economic disruption from hazard events.

5.2.4 Growth Trends & Future Development
The Town of Yountville has experienced moderate growth since the 1970s, with development patterns shaped by adopted growth management policies, infrastructure capacity, and regional housing demand.

Growth in recent decades has occurred primarily through planned residential development and visitorserving commercial uses. This approach reflects the Town’s long-standing emphasis on directing growth toward areas that can be efficiently served by public services and infrastructure while limiting outward expansion into agricultural and environmentally sensitive lands.

Residential growth has been driven largely by approved specific plans and infill development within existing neighborhoods. Recent development activity has included a mix of single-family and multi-family CAL OES SUBMITTAL - JUNE 2026
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housing intended to accommodate population growth and meet state-mandated housing requirements. The Town’s Housing Element and Annual Progress Reports document continued efforts to increase housing supply while addressing affordability, infrastructure demands, and community character.

Future development in Yountville is expected to continue focusing on buildout of remaining developable parcels within the Urban Limit Line and Sphere of Influence. Planned growth areas are generally located near existing transportation corridors, utilities, and employment centers, supporting more compact and efficient development patterns. This strategy reduces the need for extensive new infrastructure and helps limit exposure to hazards associated with hillside development, wildfire risk, and access constraints.

Economic development is also anticipated to remain a key component of future growth. Expansion and intensification of industrial and commercial uses, particularly those related to logistics, manufacturing, and the wine industry, are expected to support employment and fiscal stability. At the same time, continued development in low-lying areas and near critical transportation routes underscores the importance of incorporating hazard mitigation and climate adaptation measures into future land use and infrastructure planning.

5.3 Planning Process
The Town of Yountville followed the planning process detailed in Volume 1, Section 2, including participating in the county-wide Hazard Mitigation Planning Team (HMPT) and formulating their own internal planning team to support the broader planning process.

The town’s representatives in the Steering Group led stakeholder and public engagement efforts alongside the Consultant Team, with assistance from the county-wide HMPT and their internal planning team. This engagement process is described in Volume 1. Specifically, for the Town of Yountville, this included postings to the town website and social media, and outreach events, as documented in Appendix B. Examples of Key Stakeholders engaged by Napa County on behalf of the Town with relevance to the development of Yountville’s mitigation strategy include the USDA and other federal agencies; CAL FIRE and other state agencies; other neighboring jurisdictions; community-based organizations such as the Chamber of Commerce; utility providers like PG&E; UC Davis and other academia; and local businesses.

All Key Stakeholders that were invited to participate in the planning process are listed in Volume 1, Section 2, and the input received from stakeholders was integrated into the town’s annex, as described in Volume 1 Table 2-9. The town’s internal planning team participants, their positions, and how they participated in the planning process are shown in Table 5-8.

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Table 5-8: Town of Yountville Planning Team and Steering Group Members Team Members Title Description of Involvement
Hilary Gaede Communications Director /
Town Clerk Lead Point-of-Contact, HMPT #1 and #2, BO #1 and #2 John Ferons Public Works Director Alternate Point-of-Contact, HMPT #4 Beatriz Becerra Management Fellow Participating Stakeholder, BO #1 Diane Levine Associate Planner Participating Stakeholder, BO #1 Jacob Solis
Engineering Tech –
Geographic Information
Systems
Participating Stakeholder, BO #1 and #2
Town of Yountville participated in a comprehensive hazard mitigation planning process as part of the 2026 Napa County MJHMP update. This included a series of breakout meetings, listed in Table 5-9 that engaged the district’s planning team, which included key town personnel and stakeholders in evaluating hazards, identifying local vulnerabilities, and prioritizing mitigation strategies.

The process began with a County-Wide Steering Group Kickoff Meeting on February 28, 2024. This initial meeting focused on welcoming participants, establishing a shared understanding of the project scope and schedule, clarifying roles and responsibilities of the Steering Group, the county-wide Hazard Mitigation Planning Team (HMPT), and individual jurisdictional planning teams, and included a review of key changes since the 2020 Local Hazard Mitigation Plan The meeting set the foundation for coordinated participation throughout the planning effort.

On June 18, 2025, participants engaged in a hexagon mapping activity designed to visually identify mitigation actions that could benefit from or require inter-jurisdictional coordination. These collaborative efforts helped shape a refined set of mitigation alternatives, establish shared planning goals, and align local strategies with FEMA’s Hazard Mitigation Assistance (HMA) funding framework.

During the November 6, 2025, breakout out meeting, discussions concentrated on community engagement outcomes, initial risk assessments, and the integration of demographic data to better understand vulnerable populations. Jurisdictional teams reviewed their specific hazard exposures using the Risk Assessment Mapping Platform (RAMP) and participated in prioritization exercises to identify their top hazards.

The November 19, 2025, breakout meeting shifted toward reviewing local capabilities and defining specific areas of concern, which informed the drafting of problem statements. Teams worked collaboratively to refine mitigation alternatives, align actions with FEMA guidelines, and develop a shortlist of priority mitigation actions and inter-jurisdictional collaboration opportunities.

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