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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-WF-NVC126Wildfire PPRO -
Property
Protection ,
NRP - Natural
Resource
Protection
2020 Napa
Valley
College
Implement
WUI Risk
Reduction
Measures
Conduct vegetation management, create
defensible space, and install ignition-resistant
building features in WUI-adjacent areas of
campus to reduce wildfire and post-fire hazard
exposure.
Facility
Maintenance
Medium High 1-3 Years Project HMGP / BRIC ,
General Fund ,
CalFIRE
High ps-WF-NVC-180, ps-WF-NVC180
ma-WF-NVC228Wildfire PPRO -
Property
Protection
2026 Napa
Valley
College
Enhance
Indoor Air
Quality
Protection
Install and maintain high-efficiency filtration
systems and portable air purifiers to mitigate
wildfire smoke impacts and update operational
protocols for smoke events.
Facilities
Maintenance
High High 3-5 Years Project HMGP / BRIC ,
General Fund
Medium ps-WF-NVC-348, ps-WF-NVC180, ps-EH-NVC-352
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10.6.3 Status of Previous Mitigation Actions
In 2020, Napa Valley College 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 10-14 provides status updates for all of the previous mitigation actions in the college’s annex from 2020, from which many of the mitigation actions in Table 10-13 were sourced and revised.
Table 10-14: Napa Valley College Status of Previous Mitigation Actions Mitigati
on No.
Hazard
Type
Status Year Primary
Agency
Title/Description Reason Cancelled/
Completed
ma-EQNVC-41
Earthquake Ongoing 2020 Napa Valley
College
All-Hazard Emergency
Response Plan & Drills
Revised
ma-EQNVC-42
Earthquake Ongoing 2020 Napa Valley
College
Seismic Design & Retrofit of
Critical Facilities
Revised
ma-FLNVC-68
Flood Ongoing 2013 Napa Valley
College
Grounds Team Training in
Drainage Infrastructure
Maintenance
Revised
ma-WFNVC-126
Wildfire Ongoing 2020 Napa Valley
College
Implement WUI Risk Reduction
Measures
Revised
ma-EQNVC-43Earthquake Cancelled 2013 Napa Valley
College
Research geological soil
makeup of lower tier of campus
to determine if additional
structural mitigation steps are
necessary.
NVC-04-2020 & NVC-05-2013
combined and revised
ma-FLNVC-110Flood Cancelled 2020 Napa Valley
College
Storm water collection location
check valves
NVC-01-2013, NVC-07-2020 &
NVC-206-2020 combined and
revised
ma-SWNVC-125Severe
Weather
Cancelled 2020 Napa Valley
College
Perform a feasibility study for
flood proofing options and
analyze the drainage systems
on campus.
NVC-01-2013, NVC-07-2020 &
NVC-206-2020 combined and
revised
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Section 11. Napa Valley Transportation Authority
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Napa County
2026 Multi-Jurisdictional Hazard Mitigation Plan Update Napa Valley Transportation Authority (NVTA)
Special Agency Annex
Section 11. Napa Valley Transportation Authority..............................................................11-7
11.1 Scope & Purpose ....................................................................................................................................................................11-7
11.2 Jurisdictional Setting..........................................................................................................................................................11-7
11.2.1 Geography & Climate .................................................................................................................................................11-9
11.2.2 Demographics & Vulnerable Populations........................................................................................................ 11-12
11.2.3 Economy...................................................................................................................................................................... 11-20
11.2.4 Growth Trends & Future Development............................................................................................................. 11-21
11.3 Planning Process ................................................................................................................................................................11-23
11.3.1 Public Input & Draft Review ..................................................................................................................................11-25
11.4 What’s New........................................................................................................................................................................... 11-26
11.4.1 Mitigation Activities ............................................................................................................................................... 11-26
11.4.2 Mitigation Successes.............................................................................................................................................. 11-27
11.5 Risk Assessment................................................................................................................................................................. 11-31
11.5.1 Hazard Screening & Prioritization .....................................................................................................................11-32
11.5.2 Vulnerability to Specific Hazards.......................................................................................................................11-36
11.5.3 Climate Change Impacts & Vulnerable Populations...................................................................................11-52
11.5.4 Hazard Problem Statements.................................................................................................................................11-53
11.6 Mitigation Strategy ............................................................................................................................................................11-55
11.6.1 Capabilities & Opportunities.................................................................................................................................11-56
11.6.2 Napa Valley Transportation Authority Mitigation Action Plan ............................................................ 11-66 CAL OES SUBMITTAL - JUNE 2026
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List of Figures
Figure 11-1: NVTA Geographic Overview Map.......................................................................................................................11-11 Figure 11-2: VineGo Paratransit Shuttle................................................................................................................................. 11-29 Figure 11-3: Ribbon Cutting new at the new Vine Transit Maintenance Facility................................................. 11-30 Figure 11-4: NVTA Risk Assessment Matrix ........................................................................................................................ 11-34 Figure 11-5: NVTA Wildfire Risk................................................................................................................................................ 11-39 Figure 11-6: NVTA Earthquake Risk (M7.1 Hunting Creek–Berryessa) ..................................................................... 11-42 Figure 11-7: NVTA Earthquake Risk (M6.7 West Napa).................................................................................................... 11-43 Figure 11-8: NVTA Flood Risk (FEMA and DWR Awareness Zones)........................................................................... 11-46 Figure 11-9: NVTA Landslide Susceptibility......................................................................................................................... 11-49 Figure 11-10: Mitigation Action Number Key....................................................................................................................... 11-66 List of Tables
Table 11-1: Napa County Income and Poverty ......................................................................................................................11-15 Table 11-2: Napa County Renter- and Owner-Occupied Housing.................................................................................11-15 Table 11-3: Napa County Households with Seniors............................................................................................................11-16 Table 11-4: Napa County Households with Children .........................................................................................................11-17 Table 11-5: Napa County Population with Disabilities and Access to Transportation.........................................11-18 Table 11-6: Napa County Household Languages..................................................................................................................11-19 Table 11-7: NVTA Planning Team and Steering Group Members................................................................................ 11-23 Table 11-8: NVTA Planning Team Meetings......................................................................................................................... 11-25 Table 11-9: NVTA Document Review of Potential Hazards............................................................................................ 11-33 Table 11-10: NVTA Hazards Prioritization Summary........................................................................................................ 11-35 Table 11-11: NVTA Facilities Wildfire Exposure .................................................................................................................. 11-38 Table 11-12: NVTA Linear Infrastructure Wildfire Exposure.......................................................................................... 11-38 Table 11-13: NVTA Facilities Earthquake Risk (M7.1 Hunting Creek–Berryessa)...................................................11-41 Table 11-14: NVTA Linear Assets Earthquake Risk (M7.1 Hunting Creek–Berryessa) .........................................11-41 Table 11-15: NVTA Facilities Earthquake Risk (M6.7 West Napa) .................................................................................11-41 Table 11-16: NVTA Linear Assets Earthquake Risk (M6.7 West Napa)........................................................................11-41 Table 11-17: NVTA Linear Asset in FEMA Flood Zones.................................................................................................... 11-47 Table 11-18: NVTA Facilities in FEMA Flood Zones........................................................................................................... 11-47 Table 11-19: NVTA Linear Assets in Landslide Susceptibility Zones ......................................................................... 11-48 Table 11-20: NVTA Facilities in Landslide Susceptibility Zones.................................................................................. 11-48 Table 11-21: NVTA Hazard Problem Statements................................................................................................................. 11-53 Table 11-22: NVTA Capabilities and Opportunities Assessment................................................................................. 11-62 Table 11-23: NVTA Mitigation Action Plan............................................................................................................................ 11-68 CAL OES SUBMITTAL - JUNE 2026
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Adoption Resolution
To comply with the Federal Disaster Mitigation Act of 2000 (DMA 2000), the Napa Valley Transportation Authority Board of Directors 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 district’s commitment to reducing the impacts of natural hazards within its jurisdiction and across Napa County.
A copy of the district’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 11. Napa Valley Transportation Authority
11.1 Scope & Purpose
This Jurisdictional Annex for the Napa Valley Transportation Authority (NVTA) of the 2026 Napa County Multi-Jurisdictional Hazard Mitigation Plan (MJHMP) details the hazard mitigation planning elements specific to the district’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 district.
This annex provides additional information specific to the district, with a focus on hazard identification and risk assessment, vulnerability assessment, problem statements, mitigation strategy, and capabilities assessment. Below are NVTA’s Points of Contact:
Primary Point of Contact Alternate Point of Contact
Libby Payan, Senior Program Planner /
Administrator
Napa Valley Transportation Authority
625 Burnell Street
Napa, CA 94559
Telephone: (707) 259-8631
email: [email protected]
Dexter Cypress, Transit Planner
Napa Valley Transportation Authority
625 Burnell Street
Napa, CA 94559
Telephone: (707) 259-8631
email: [email protected]
11.2 Jurisdictional Setting
The Napa Valley Transportation Authority (NVTA) serves as the designated county-wide transportation planning agency for Napa County and is responsible for coordinating the development, funding, and implementation of transportation programs, projects, and policies throughout the Napa Valley. NVTA functions as both a transportation planning authority and a transit operator through its management of Vine Transit, the county’s public transit system.
NVTA’s jurisdiction encompasses the entirety of Napa County, including the incorporated Cities of American Canyon, Calistoga, Napa, and St. Helena, the Town of Yountville, and the unincorporated areas of Napa County. This responsibility positions NVTA as a central coordinating entity linking local transportation needs with regional transportation strategies.
NVTA plays a critical role in connecting Napa County’s transportation system to broader regional planning frameworks led by the Metropolitan Transportation Commission (MTC). The Countywide Transportation Plan was developed as part of the regional planning process that culminates in Plan Bay Area, ensuring that Napa County’s transportation investments align with regional mobility, safety, and sustainability objectives.
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hazards affecting Napa County, including wildfire, earthquake, and flooding, do not conform to jurisdictional boundaries.
Congestion Management Agencies were established statewide following the passage of Proposition 111 by California voters in 1990. Proposition 111 increased the state fuel tax and required urban counties to designate a Congestion Management Agency responsible for coordinating transportation planning, programming, and congestion management activities. Within Napa County, NVTA fulfills this statutory role by managing transportation funding programs, developing long-range transportation plans, and coordinating investments that support mobility, safety, and system performance.
NVTA operates as both a planning and funding authority. The agency receives and administers a variety of funding sources, including state transportation funds, federal Surface Transportation Program (STP) funds, Transportation Development Act (TDA) funds, and other revenues apportioned to urbanized areas. As a designated federal Transportation Management Area (TMA), NVTA is responsible for complying with additional federal planning and programming requirements while benefiting from access to federal transportation funding programs. This designation further reinforces NVTA’s role as Napa County’s primary conduit for transportation funding and regulatory coordination.
Beyond traditional transportation planning functions, NVTA administers several specialized programs tied to broader public policy objectives. As program manager for the Transportation Fund for Air Quality, NVTA supports projects and strategies designed to reduce vehicle emissions and improve regional air quality.
NVTA also coordinates Transportation Development Act (TDA) funds in partnership with the Metropolitan Transportation Commission, ensuring that resources are allocated to transit, paratransit, streets and roads, and bicycle and pedestrian improvements. Additionally, NVTA serves as the Abandoned Vehicle Abatement Authority, administering funds derived from vehicle registration fees to address abandoned vehicles and related community impacts.
In addition to its planning functions, NVTA manages and operates essential elements of the county’s public transportation network. Through Vine Transit, Napa County’s public transit system, NVTA provides fixedroute transit services and ADA-mandated paratransit services that support daily mobility, access to employment, and transportation for vulnerable populations. NVTA also oversees transit-related infrastructure, including fleet assets, maintenance facilities, administrative facilities, and supporting systems necessary for transit operations.
The scale of the countywide roadway network further illustrates the breadth of NVTA’s planning environment. Napa County contains more than 1,500 miles of roads, many of which are subject to ongoing maintenance and rehabilitation needs. This extensive network must accommodate local travel, regional commuting patterns, freight movement, and significant visitor traffic associated with Napa Valley’s tourism economy.
Napa Valley’s economic profile further shapes transportation system demands. The region’s economy is strongly influenced by agriculture, tourism, hospitality, and related industries, which generate distinct travel patterns and seasonal traffic fluctuations. The Vision Zero Action Plan notes that nearly four million visitors travel to Napa Valley annually, producing significant traffic volumes and complex interactions CAL OES SUBMITTAL - JUNE 2026
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between local and regional travel. These conditions affect roadway congestion, evacuation planning, transit operations, and overall system resilience.
NVTA’s location within Napa County and the State of California are shown in Figure 11-1. ▪ Year of Incorporation: 1998
▪ Populations Served: ~137,381 (US Census Bureau, 2022) ▪ Primary Services: NVTA provides countywide transportation planning, programming and funding administration, and operates public transit services through the Vine Transit system.
11.2.1 Geography & Climate
NVTA operates within Napa County, a region defined by its distinctive geographic features and Mediterranean climate, both of which strongly influence transportation infrastructure, system performance, and hazard vulnerability. Napa County is characterized by a long, narrow valley oriented in a northwest–southeast direction, bounded by mountain ranges that shape development patterns, travel corridors, and environmental conditions. Napa Valley is a predominantly rural and agricultural region, where communities are largely concentrated along the Valley floor and connected by a limited number of primary transportation corridors.
The Valley floor serves as the primary location for urban development, transportation facilities, and major roadway infrastructure. Key travel routes, including State Route 29 and Silverado Trail, run longitudinally through the valley and function as critical mobility corridors for residents, employees, freight movement, and visitors. Surrounding the Valley floor are rolling hills and mountainous terrain, which introduce topographic constraints affecting roadway alignments, sight distances, evacuation routes, and infrastructure siting. These geographic conditions contribute to a transportation system that is highly corridor-dependent, where disruptions along major routes may have widespread system impacts.
Hydrologic features further shape Napa County’s geography and associated transportation risks. The Napa River and its tributaries traverse the Valley floor, creating areas subject to periodic flooding, localized drainage challenges, and erosion-related impacts. Seasonal storm events can affect roadway operations, transit reliability, and infrastructure integrity, particularly in low-lying areas or locations adjacent to creeks and waterways. Transportation infrastructure must therefore be designed and maintained with consideration for both flood hazards and long-term watershed dynamics.
Napa County’s climate is generally classified as Mediterranean, characterized by warm, dry summers and cool, wet winters. The Countywide Transportation Plan acknowledges that the region experiences distinct seasonal variability, including concentrated precipitation during winter months and extended dry periods during summer. This climatic pattern contributes to several transportation-relevant hazard conditions.
Winter storms may produce heavy rainfall, localized flooding, debris flows, and reduced roadway visibility, while prolonged dry seasons contribute to elevated wildfire risk, heat-related stress on infrastructure, and increased likelihood of drought conditions.
Wildfire represents one of the most significant climate-influenced hazards affecting Napa County. The combination of seasonal drought, high summer temperatures, low humidity, and wind-driven fire behavior CAL OES SUBMITTAL - JUNE 2026
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creates conditions conducive to large wildfire events. Transportation networks frequently serve as both evacuation routes and operational lifelines during wildfire incidents, making roadway reliability, traffic management, and transit continuity critical resilience considerations. Wildfire impacts may include roadway closures, reduced visibility from smoke, damage to transportation assets, and interruptions to power and communication systems supporting transit operations.
Temperature variability also influences transportation system performance. High summer temperatures may contribute to pavement degradation, increased vehicle breakdowns, and operational challenges for both transit fleets and passengers. Conversely, winter conditions, while generally mild compared to other regions, can introduce reduced traction, localized icing in elevated areas, and storm-related hazards affecting roadway safety.
Climate change considerations are increasingly relevant to Napa County’s transportation planning environment. Regional planning documents recognize that changing temperature patterns, altered precipitation intensity, and increasing frequency of extreme weather events may amplify existing hazards, including wildfire, flooding, and heat-related impacts. These evolving conditions require transportation agencies such as NVTA to incorporate resilience and adaptation strategies into long-range planning, capital investment decisions, and operational policies.
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Figure 11-1: NVTA Geographic Overview Map
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11.2.2 Demographics & Vulnerable Populations
NVTA serves a population whose demographic characteristics significantly influence transportation needs, system design, and hazard vulnerability. Napa County’s population profile differs from many other Bay Area counties, particularly in terms of age distribution, disability prevalence, and the geographic distribution of transit-dependent residents.
According to the Accessible Transportation Needs Assessment (ATNA), Napa County has one of the highest proportions of older adults within the San Francisco Bay Area. The ATNA notes that Napa County has the second-highest percentage of residents over the age of 65 among Bay Area counties, exceeded only by Marin County. This age distribution has direct implications for transportation planning and hazard mitigation.
Older adults are more likely to rely on public transportation services, paratransit, and community-based mobility programs, while also facing increased physical vulnerability during hazard events. (NVTA ATNA, 2025)
The ATNA further identifies that Napa County has the second-highest percentage of individuals with disabilities in the Bay Area, exceeded only by Solano County. Individuals with disabilities often experience heightened transportation challenges, including dependence on accessible transit services, greater sensitivity to service disruptions, and increased difficulty during emergency evacuations. These conditions reinforce NVTA’s role not only as a transportation provider but also as a critical lifeline agency during hazard events. (NVTA ATNA, 2025)
Vulnerable populations within Napa County extend beyond age and disability classifications. The Community-Based Transportation Plan (CBTP) highlights the presence of Equity Priority Communities (EPCs), defined by the Metropolitan Transportation Commission as census tracts with concentrations of populations that may experience disproportionate transportation burdens. These include low-income households, communities of color, seniors, individuals with disabilities, residents with limited English proficiency, households without access to private vehicles, and other historically underserved groups. (NVTA CBTP, 2025)
Within Napa County, both regionally designated and locally identified EPCs reflect areas where residents may be more dependent on public transportation services and more vulnerable to transportation disruptions. The CBTP identifies multiple EPCs distributed across the City of Napa, Calistoga, St. Helena, American Canyon, and unincorporated communities. Residents within these communities often face transportation barriers related to cost, service frequency, physical infrastructure limitations, and geographic accessibility. During hazard events, these barriers may be amplified by roadway closures, transit interruptions, or power outages affecting transportation operations.
Transit-dependent populations represent a particularly important consideration for NVTA’s hazard mitigation planning. Many residents rely on Vine Transit services for access to employment, healthcare, education, and essential services. Disruptions affecting transit operations, including fleet availability, CAL OES SUBMITTAL - JUNE 2026
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fueling or charging infrastructure, communications systems, or roadway access, may therefore produce disproportionate impacts on vulnerable groups.
NVTA administers several specialized mobility programs designed to expand transportation access for seniors and individuals with disabilities beyond traditional fixed-route transit service. The Shared Vehicle Program provides qualifying nonprofit 501(c)(3) organizations that serve elderly individuals and persons with disabilities with access to NVTA-owned vehicles, enabling partner agencies to deliver client transportation services. Under this program, participating organizations supply qualified drivers, fuel, and required insurance coverage, while NVTA provides the vehicles, performs driver screening, delivers training, and maintains the fleet. This arrangement allows community-based organizations to enhance mobility services without the capital costs associated with vehicle ownership.
Complementing this program, the Taxi Scrip Program functions as a subsidized lifeline service for eligible City of Napa residents who are seniors 65+ or persons with disabilities. The program is designed to supplement, rather than replace, regular Vine Transit service by providing reduced-cost taxi trips within the City of Napa for circumstances when fixed-route transit may be unavailable or impractical, such as evening travel or health-related limitations. NVTA subsidizes up to up to 50% of the first $18 of the cab ride fare of each trip cost, thereby improving flexible, on-demand mobility for eligible participants.
Additionally, VineGo Paratransit Service provides ADA-compliant, shared-ride, curb-to-curb transportation for certified individuals whose disabilities prevent them from independently using the fixed-route bus system. VineGo operates within three quarters of a mile to the fixed-route network, ensuring that individuals with mobility limitations retain access to essential destinations, services, and community resources. Collectively, these programs play a critical role in advancing transportation equity, accessibility, and system resilience throughout Napa County.
Visitors and seasonal workforce populations also contribute to Napa County’s demographic landscape. Napa Valley’s tourism-driven economy attracts millions of visitors annually, while agricultural and hospitality industries generate commuting patterns involving employees traveling from surrounding counties. These populations increase overall system demand and introduce additional complexity during emergencies, particularly when evacuation or sheltering actions are required.
From a hazard mitigation perspective, vulnerable populations are often more sensitive to transportation system disruptions. Older adults, individuals with disabilities, low-income households, and residents without private vehicles may experience greater difficulty accessing emergency information, securing alternative transportation, or adapting to extended service interruptions. Transportation infrastructure and services therefore play a critical role in supporting community resilience, enabling evacuation, facilitating emergency response, and maintaining access to essential destinations.
Income & Housing
Income and housing conditions within Napa County play an important role in shaping transportation needs and vulnerability for populations served by the NVTA. Napa County is characterized by a high cost of living CAL OES SUBMITTAL - JUNE 2026
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driven largely by housing affordability pressures, which have direct implications for transportation access and travel behavior. Regional and county planning documents consistently note that housing costs consume a disproportionate share of household income for many residents, particularly low-income households, seniors on fixed incomes, and service-sector workers employed in Napa Valley’s tourism and agricultural economy.
The Community-Based Transportation Plan (CBTP) identifies numerous Equity Priority Communities (EPCs) where residents are more likely to be low income, cost-burdened by housing expenses, and dependent on public transportation. These communities include areas within the City of Napa, Calistoga, St.
Helena, American Canyon, and select unincorporated areas. In many cases, rising housing costs have pushed lower-income households farther from employment centers and essential services, increasing reliance on transit, shared mobility, and demand-responsive transportation programs.
Housing patterns in Napa County are also geographically constrained by agricultural land preservation policies, environmental protections, and limited developable land. As a result, new housing supply has not kept pace with demand, contributing to affordability challenges and longer commute distances for many workers. The Countywide Transportation Plan acknowledges that a significant share of the local workforce commutes into Napa County from surrounding counties, reflecting a mismatch between housing availability and employment locations. These commuting patterns place additional strain on regional transportation corridors and increase vulnerability to service disruptions during hazard events.
Income and housing insecurity can compound transportation vulnerability during emergencies.
Households with limited financial resources or unstable housing are less likely to have access to private vehicles, alternative transportation options, or flexible work arrangements. During wildfires, floods, or severe weather events, these populations may depend heavily on public transit, paratransit, and community-based transportation services for evacuation, access to shelters, and recovery-related travel.
Transportation disruptions therefore have the potential to disproportionately affect residents already experiencing economic and housing-related stress.
NVTA’s planning and funding programs directly intersect with these conditions by prioritizing investments that improve access to transit, reduce transportation costs, and support affordable mobility options.
Programs supported through the Transportation Development Act, Transportation Fund for Air Quality, and Community-Based Transportation Planning efforts are specifically intended to mitigate the combined burdens of housing cost, income limitations, and transportation access. From a hazard mitigation perspective, understanding income and housing conditions is essential for ensuring that transportation systems remain reliable, affordable, and accessible for populations most at risk during emergency events and recovery periods.
Volume 1 provides the demographic characteristics of Napa County as a whole. Median income and poverty rates for Napa County are summarized in Table 11-1. As shown in the table, the median income for Napa County is close to $106,000 and the poverty rate is close to 8%.
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Owner- and renter occupied numbers are provided in Table 11-2. As shown in the table, renters account for 35% of households and owners account for 65% of households in Napa County.
Table 11-1: Napa County Income and Poverty
Area Median Income Poverty Rate
Napa County (Unincorporated) $105,809 7.9%
American Canyon $122,694 7.4%
Calistoga $96,667 5.4%
Napa (City) $100,273 8.1%
St. Helena $135,781 5.7%
Yountville $75,134 10.6%
Source: ACS 5-Year, 2017-2022
Table 11-2: Napa County Renter- and Owner-Occupied Housing Area Total Occupied Housing Units Renter Rent % Owner Own % Napa County (Unincorporated) 49,218 17,142 35% 32,076 65% American Canyon 5,725 1,205 21% 4,520 79%
Calistoga 2,116 776 37% 1,340 63%
Napa (City) 29,443 12,052 41% 17,391 59%
St. Helena 2,466 792 32% 1,674 68%
Yountville 1,516 514 34% 1,002 66%
Source: ACS 5-Year, 2017-2022
Dependent & Disabled Populations
NVTA serves a population that includes a significant number of individuals who are transportationdependent due to age, disability, medical conditions, or limited access to private vehicles. These populations represent a critical consideration in hazard mitigation planning because their mobility, safety, and access to essential services are closely tied to the continuity and reliability of public transportation systems.
Individuals with disabilities frequently encounter structural and operational barriers that increase reliance on specialized and accessible transportation services. Physical mobility impairments, sensory limitations, cognitive disabilities, and chronic health conditions may restrict the ability to drive, walk extended distances, or independently utilize conventional fixed-route transit. NVTA addresses these needs through programs such as VineGo Paratransit Service, the Taxi Scrip Program, and partnerships supported by the Shared Vehicle Program, which collectively support equitable mobility for individuals with access and functional needs.
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Transportation-dependent populations are particularly vulnerable during hazard events. Individuals who cannot drive or who require accessible vehicles may have limited evacuation options and may rely heavily on public transit systems for emergency mobility. Disruptions affecting transit operations, roadway accessibility, fueling or charging infrastructure, power supply, or communications systems may therefore produce disproportionate impacts on disabled and dependent populations. Extended service interruptions may affect not only mobility but also access to medical care, prescription services, grocery stores, employment, and essential social support networks. From a hazard mitigation perspective, maintaining transportation system resilience is therefore directly linked to protecting vulnerable populations, reducing life safety risks, and supporting community continuity and recovery. NVTA’s role extends beyond mobility provision, functioning as a critical lifeline agency during emergencies.
Age represents a key factor influencing dependency and vulnerability to natural hazards. Older adults and children are widely recognized as dependent populations due to their reliance on caregivers for safety, mobility, and decision-making during emergency events. These populations often face heightened risks during disasters such as wildfires, floods, and earthquakes, particularly when compounded by disability, economic limitations, or social isolation. Volume 1 provides the demographic characteristics of Napa County as a whole.
Within Napa County, approximately 34 percent of households include at least one individual over the age of 65, and nearly 9 percent of all households consist of seniors living alone (Table 11-3). While only approximately 2 percent of senior households live below the poverty line, older adults, particularly those who are low-income, mobility-limited, or socially isolated, remain among the most vulnerable populations during hazard events. Challenges affecting older adults may include reduced mobility, chronic medical conditions, limited access to private transportation, reduced digital literacy, and diminished access to realtime emergency alerts. Seniors living alone may require additional assistance during evacuations, power outages, or extended service disruptions, while assisted living and congregate care facilities require advanced coordination to ensure continuity of care and resident safety.
Table 11-3: Napa County Households with Seniors
Households with 65+
Area Households 65+ %
65+
Alone %
65+
Poverty %
Napa County (Unincorporated) 55,588 18,777 33.8% 4,816 8.7% 1,271 2.3% American Canyon 5,924 1,772 29.9% 184 3.1% 111 1.9%
Calistoga 2,330 1,003 43.0% 419 18.0% 101 4.3%
Napa (City) 31,666 10,299 32.5% 2,674 8.4% 703 2.2%
St. Helena 2,963 1,153 38.9% 296 10.0% 42 1.4%
Yountville 1,824 873 47.9% 351 19.2% 77 4.2%
Source: ACS 5-Year, 2017-2022
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Children represent another dependent population requiring special consideration (Table 11-4). In Napa County, approximately 26 percent of households include individuals under the age of 18, with approximately 6 percent 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 affecting schools, childcare facilities, and youth services may produce cascading social, economic, and developmental impacts. Households with limited financial resources or single caregivers may face additional challenges securing transportation, temporary housing, emergency supplies, and recovery assistance.
Table 11-4: Napa County Households with Children
Households with Children <18
Area Households <18 %
<18 Single
Caregiver %
Napa County (Unincorporated) 55,588 14,596 26.3% 3,109 5.6% American Canyon 5,924 2,633 44.4% 417 7.0%
Calistoga 2,330 471 20.2% 33 1.4%
Napa (City) 31,666 8,934 28.2% 2,315 7.3%
St. Helena 2,963 619 20.9% 168 5.7%
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 the combined effects of age-related health conditions, mobility limitations, and potential social isolation. In American Canyon, approximately 10 percent of the non-institutionalized population lives with a disability, compared to approximately 12 percent countywide (Table 11-5). Among populations with access and functional needs, elderly individuals with disabilities represent a particularly vulnerable subgroup. This population includes seniors living with physical, sensory, or cognitive impairments, including reduced mobility, hearing or vision loss, reliance on assistive medical devices, neurocognitive conditions, and chronic health conditions that may be exacerbated by hazard events such as wildfire smoke exposure or extreme heat.
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Table 11-5: Napa County Population with Disabilities and Access to Transportation Area Population
Persons w
Disability %
Persons
Reliant
on Public
Trans. % Households
HH w
No
Vehicle %
Napa County 137,384 16,544 12.0% 890 0.6% 55,588 2,421 4.4% American Canyon 21,669 2,201 10.2% 287 1.3% 5,924 138 2.3% Calistoga 5,191 573 11.0% 36 0.7% 2,330 83 3.6%
Napa (City) 79,233 9,837 12.4% 291 0.4% 31,666 1,554 4.9% St. Helena 5,426 683 12.6% 121 2.2% 2,963 219 7.4%
Yountville 3,397 683 20.1% 15 0.4% 1,824 210 11.5%
Source: ACS 5-Year, 2017-2022
The interaction between advanced age and disability may also present challenges for long-term hazard mitigation. Elderly individuals with disabilities may encounter physical, financial, or logistical barriers when implementing resilience improvements. Activities such as seismic retrofitting, anchoring fuel tanks, foundation bracing, defensible space maintenance, or residential flood-proofing measures may be constrained by mobility limitations, fixed incomes, and access to technical or financial assistance. Many older adults reside in aging housing stock that may be more susceptible to earthquake damage or repetitive hazard impacts, further increasing long-term vulnerability.
Race, Ethnicity & Language
NVTA serves a service area characterized by substantial racial, ethnic, and cultural diversity. Several areas within the county exhibit higher concentrations of Hispanic or Latino residents, particularly within central and southern residential neighborhoods, while other areas are characterized by predominance of White residents or Asian residents. Smaller but meaningful concentrations of additional racial and ethnic groups are distributed throughout the county. This diversity is especially pronounced in communities such as American Canyon, which is widely recognized as one of the most demographically diverse jurisdictions within Napa County.
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.
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Racial and ethnic diversity has important implications for transportation planning, service delivery, and hazard mitigation. Travel behavior, transit reliance, and access to resources are often shaped by socioeconomic conditions, cultural factors, and historical patterns of development. Communities of color are more likely to include transit-dependent populations, households with fewer private vehicles, and residents employed in service-sector or shift-based occupations. As a result, disruptions affecting transportation infrastructure or transit operations may produce disproportionate impacts across certain racial and ethnic groups.
Language diversity further influences vulnerability within NVTA’s service area. Residents with limited English proficiency (LEP) may encounter heightened barriers to understanding emergency alerts, accessing preparedness information, navigating evacuation procedures, and utilizing recovery assistance programs.
According to ACS data, approximately 16 percent of households in Napa County speak Spanish at home, while approximately 4 percent of households report limited English proficiency (Table 11-6). In addition, according to passenger onboard surveys, nearly 1/3 of current NVTA riders are Spanish speaking individuals. These conditions underscore the importance of accessible and multilingual communication strategies, particularly during hazard events when timely dissemination of emergency information is critical to life safety.
Language barriers may also affect routine transportation access. Individuals with LEP may experience challenges interpreting service changes, detours, safety information, and emergency notifications affecting transit operations. During hazard events, these communication challenges may be amplified by rapidly evolving conditions, infrastructure disruptions, and the need for coordinated response actions. Ensuring that emergency messaging, service updates, and safety instructions are linguistically accessible remains an important component of transportation system resilience.
The spatial variability of racial and ethnic composition throughout Napa County, reinforces that vulnerability and service needs are not uniformly distributed. Certain neighborhoods may require targeted outreach, culturally appropriate engagement strategies, and multilingual emergency communications to ensure equitable access to transportation services and emergency information. These considerations are directly relevant to NVTA’s planning, operations, and hazard mitigation efforts, as transportation systems serve a critical lifeline function for diverse populations before, during, and after disaster events.
Table 11-6: Napa County Household Languages
Area Households (HH) Spanish Speaking % Limited English % Napa County 55,588 8,738 15.7% 2,141 3.9%
American Canyon 5,924 1,069 18.0% 177 3.0%
Calistoga 2,330 474 20.3% 63 2.7%
Napa (City) 31,666 5,800 18.3% 1,653 5.2%
St. Helena 2,963 370 12.5% 88 3.0%
Yountville 1,824 49 2.7% 21 1.2%
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Source: ACS 5-Year, 2017-2022
Social Vulnerability Index (SVI)
The Centers for Disease Control and Prevention (CDC) Social Vulnerability Index (SVI) for Napa County 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).
While Napa County is not uniformly classified as highly vulnerable when compared to other regions, localized patterns of social vulnerability are evident. NVTA’s CBTP identifies multiple Equity Priority Communities (EPCs) where residents exhibit higher concentrations of characteristics commonly associated with elevated vulnerability, including lower incomes, higher percentages of seniors, greater prevalence of disability, limited vehicle access, and language barriers.
Similarly, the CBTP notes that certain unincorporated communities experience higher rates of low-income residents, seniors, individuals with disabilities, and residents who report limited English proficiency or lack of vehicle access. These overlapping conditions illustrate how social vulnerability is spatially concentrated rather than evenly distributed throughout Napa County.
Social vulnerability directly intersects with transportation system performance. Households with limited financial resources, individuals without access to private vehicles, seniors living alone, residents with disabilities, and individuals with limited English proficiency are more likely to depend on public transit systems both during routine conditions and emergency events. Hazard-related disruptions affecting transit operations, roadway networks, fueling or charging infrastructure, or communications systems may therefore produce disproportionate impacts on socially vulnerable populations.
Volume 1 provides a summary of Napa County’s SVI as a whole.
11.2.3 Economy
NVTA operates within an economic environment that is both regionally significant and uniquely sensitive to disruption. Napa County’s economy is strongly influenced by tourism, hospitality, agriculture, and wine production, sectors that collectively drive employment, generate tax revenues, and shape regional travel patterns. The county’s global reputation as a premier tourism and wine destination results in substantial visitor activity, seasonal fluctuations in travel demand, and a workforce that relies heavily on the regional transportation system.
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generation. These industries are closely tied to transportation system performance, as visitors depend on roadway corridors, transit services, and multimodal infrastructure to access destinations throughout the Valley. Hazard events such as wildfires, floods, or severe weather may therefore produce economic consequences that extend beyond physical damage, including declines in visitation, business interruptions, and reductions in sales and occupancy tax revenues.
Agriculture, particularly viticulture, forms another foundational component of the county’s economy. Napa County’s agricultural lands support wine production, food processing, and related economic activities.
These sectors depend on reliable transportation networks for workforce mobility, goods movement, and supply chain continuity. Transportation disruptions may affect employee access, freight reliability, and the movement of time-sensitive agricultural products.
Employment patterns within Napa County further illustrate the economic importance of transportation.
Regional planning documents consistently note that a substantial portion of the county’s workforce commutes from neighboring counties due to housing affordability constraints. This dynamic creates strong inter-county travel flows and increases reliance on major transportation corridors. Transportation system disruptions, whether caused by hazard events or infrastructure failures, may therefore have cascading effects on labor availability, business continuity, and regional productivity.
The Countywide Transportation Plan emphasizes the relationship between transportation investments and economic sustainability, recognizing that mobility, reliability, and system connectivity are essential for supporting workforce access, tourism activity, and business operations. Transit services operated by NVTA, including local, regional, and demand-response services, provide critical connections between residential areas, employment centers, healthcare facilities, and visitor destinations. These services are particularly important for lower-income workers, seniors, individuals with disabilities, and residents without consistent access to private vehicles.
Hazard events present distinct economic risks for NVTA and the communities it serves. Wildfires, flooding, earthquakes, and slope failure may disrupt transit operations, damage transportation infrastructure, degrade air quality, and restrict corridor access. These disruptions may result in lost productivity, reduced tourism activity, service interruptions, and increased operating and recovery costs. In a tourism-dependent economy, even temporary disruptions may produce measurable financial impacts.
From a hazard mitigation perspective, transportation resilience is directly linked to economic stability.
Reliable transit operations, redundant routing options, resilient infrastructure, and continuity of operations planning help reduce the duration and severity of economic disruption following hazard events. NVTA’s role as both a transportation provider and funding administrator positions the agency as a key contributor to regional economic resilience.
11.2.4 Growth Trends & Future Development
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ahead. Although Napa County’s overall population growth has historically been slower than in many neighboring Bay Area counties, long-term trends reflect continued demand for housing, employment opportunities, and visitor-driven travel. These trends are expected to shape not only routine mobility patterns but also NVTA’s priorities related to congestion management, multimodal connectivity, and system resilience.
Regional planning projections incorporated into the Countywide Transportation Plan (CTP) anticipate moderate population growth within Napa County over the next 25 years, particularly concentrated in cities such as American Canyon, Napa, and portions of unincorporated communities within close proximity to employment centers. Growth trends are coupled with evolving economic and demographic shifts, including an aging population, increasing demand for accessible transportation services, and rising numbers of workers commuting across county lines due to housing affordability challenges. These dynamics contribute to continued pressure on transportation corridors and transit services, requiring NVTA to balance capacity, accessibility, and reliability while accommodating future travel needs.
Visitor-related growth also plays a defining role in future development patterns. Napa Valley’s global tourism market continues to expand, attracting both domestic and international visitors whose travel patterns intersect with local and regional transportation systems. Tourist activity generates unique peakperiod travel demands and places seasonal strain on key corridors such as State Route 29, State Route 121, and Silverado Trail. Planning for future development requires NVTA to account for not only resident and commuter travel but also visitor-induced congestion, which influences transit ridership, roadway performance, and the resiliency of evacuation routes during hazard events.
Land use and housing trends further influence NVTA’s planning environment. Although Napa County has historically limited large-scale residential and commercial development in order to protect agricultural lands and preserve rural character, ongoing housing needs and regional affordability pressures are prompting updated planning efforts that encourage higher-density, mixed-use development within existing urbanized areas. This trajectory supports more efficient land use, potential increases in transit ridership, and greater emphasis on multimodal transportation alternatives. However, growth pressures also raise concerns regarding equitable access to transportation, impacts on infrastructure capacity, and interaction between development patterns and hazard exposure.
Environmental and sustainability objectives increasingly shape future transportation and land use planning in Napa County. Local jurisdictions and regional partners are incorporating climate adaptation and greenhouse gas reduction strategies into comprehensive planning frameworks, emphasizing transitoriented development, active transportation infrastructure, and resilient infrastructure investments.
NVTA’s role in these efforts includes integrating hazard mitigation and climate resilience into transportation planning, ensuring that future development anticipates shifts in environmental conditions and supports sustainable mobility options.
Future development trends also underscore the importance of technological and operational innovation.
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service planning are all components of NVTA’s strategy to meet future travel demands. Integrating these innovations with growth forecasts helps position the transit system to remain responsive to demographic shifts, travel pattern changes, and evolving rider expectations.
From a hazard mitigation perspective, understanding future growth trends is essential for prioritizing investments that enhance system reliability, connectivity, and redundancy. As development continues, transportation networks must remain capable of supporting daily travel, emergency evacuation, and postevent recovery. Investments in multimodal corridors, transit infrastructure, and operational resilience help ensure that both existing and future populations can safely access essential destinations during hazard events.
11.3 Planning Process
NVTA followed the planning process detailed in Volume 1, Section 2, including participating in the countywide Hazard Mitigation Planning Team (HMPT) and formulating their own internal planning team to support the broader planning process.
The district’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 district, this included postings to the district website and social media, and outreach events, as documented in Appendix B. Examples of Key Stakeholders engaged by Napa County on behalf of the district with relevance to the development of NVTA’s mitigation strategy include the USDA and other federal agencies; CAL FIRE and other state agencies; other jurisdictions; community-based organizations such as local Chamber of Commerce chapters; 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 district’s annex, as described in Volume 1 Table 2-9. The district’s internal planning team participants, their positions, and how they participated in the planning process are shown in Table 11-7.
Table 11-7: NVTA Planning Team and Steering Group Members Team Members Title Description of Involvement
Libby Payan Senior Program Planner –
Administrator Lead Point-of-Contact, HMPT #1, BO #2
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NVTA staff 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 11-8 that engaged the district’s planning team, which included key district 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 December 10, 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.
Throughout the series of breakout meetings, the district 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.
During the September 5, 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 May 7, 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.
The meetings also included consensus-building activities around hazard rankings, capabilities, and planned actions, while providing regular updates on the overall project schedule.
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Table 11-8: NVTA 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
NVTA Planning Team
Breakout Meeting #1
September 5, 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
NVTA Planning Team
Breakout Meeting #2
May 7, 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
11.3.1 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. 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.
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.
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11.4 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. This is the first time NVTA has participated in the MJHMP process.
While not included in the 2020 plan, the district has since strengthened its focus on resilience through key efforts. Through this MJHMP process, NVTA has identified its highest-priority hazards, developed hazardspecific problem statements, and proposed actionable mitigation strategies.
By aligning with countywide partners and leveraging regional resources, NVTA has strengthened its capacity to prepare for, withstand and recover from disasters while continuing to protect its unique coastal community character.
11.4.1 Mitigation Activities
NVTA supports hazard mitigation through the integration of resilience principles into transportation planning, project development, and funding administration. Although NVTA’s primary responsibilities center on congestion management, mobility, and transit operations, many agency-led activities inherently contribute to reducing risk and enhancing the reliability of the countywide transportation system under hazard conditions.
NVTA’s long-range and short-range planning efforts serve as foundational mitigation tools. The CTP establishes policies and investment priorities that emphasize system reliability, multimodal connectivity, and corridor performance, all of which contribute to transportation network resilience. Similarly, the ShortRange Transit Plan (SRTP) identifies near-term capital investments and operational strategies necessary to maintain and enhance transit service continuity. Together, these planning frameworks guide infrastructure improvements, operational enhancements, and system modernization efforts that reduce vulnerability to disruptions associated with wildfire, flooding, seismic events, and severe weather.
NVTA also administers funding programs that enable mitigation-supporting projects. Through the coordination of state, federal, and local transportation revenues, including Surface Transportation Program (STP) funds, Transportation Development Act (TDA) funds, and Measure U sales tax revenues, NVTA directs resources toward projects that improve roadway conditions, enhance safety, increase modal alternatives, and strengthen critical transportation corridors. Measure U, in particular, provides jurisdictions with expanded flexibility to implement costlier capital improvements, address deferred maintenance, and fund projects supporting highway operations and emergency evacuations. These investments yield important mitigation co-benefits by improving corridor reliability, reducing failure risk, and enhancing emergency mobility.
Operationally, NVTA advances mitigation through transit system improvements, fleet modernization, and supporting infrastructure upgrades. Investments in vehicle replacement, electrification infrastructure, facility improvements, and communications systems contribute to service reliability and operational continuity. Multimodal initiatives, including bicycle and pedestrian infrastructure projects, further enhance system redundancy by expanding travel options during both routine and emergency conditions.
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NVTA’s mitigation-related activities are reinforced through coordination with local jurisdictions, regional agencies, and emergency management partners. Transportation networks serve a critical lifeline function during hazard events, particularly for evacuations, emergency response, and access to essential services.
NVTA’s planning and funding roles support regionally significant corridor improvements and system management strategies that reduce congestion, improve safety, and enhance the transportation system’s ability to function under stress.
11.4.2 Mitigation Successes
Lifeline Taxi Program
The Taxi Scrip Program, also referred to as the Lifeline Taxi Program, is a taxpayer-funded mobility service administered by the NVTA to supplement the regular Vine Transit fixed-route system. The program is designed to provide flexible, on-demand transportation for eligible City of Napa residents who may be unable to use traditional transit services under certain conditions. While not intended to function as a primary mode of transportation, the program serves as an important lifeline resource for seniors and persons with disabilities, particularly for evening travel after fixed-route service hours or during periods when a rider’s health or mobility limitations make bus travel impractical.
Under the program, NVTA helps eligible participants pay for taxi trips by providing PEX Visa Prepaid Cards that may be used toward eligible cab fares. The program subsidizes up to 50% of the first $18 of a taxi ride, reducing the rider’s out-of-pocket cost while maintaining the service as a supplemental transportation option. Eligible participants may use their PEX Visa Prepaid Card to pay for approved taxi trips within the City of Napa.
Eligibility for the Taxi Scrip Program is limited to residents of the City of Napa who meet defined criteria.
Qualified participants include individuals aged 65 years or older, individuals certified under the Americans with Disabilities Act (ADA), or individuals with disabilities of any age. Verification requirements ensure program integrity while enabling access for residents with documented mobility or disability-related needs.
The program operates under specific usage guidelines intended to support equitable access and financial sustainability. Taxi Scrip trips must originate and terminate within Napa city limits, and participants are subject to fare caps and ticket limits. Program rules address operational consistency, including restrictions on tipping, waiting time allowances, and replacement policies for lost or stolen identification cards.
From a hazard mitigation and resilience perspective, the Taxi Scrip Program provides an important adaptive mobility resource. During emergencies, service disruptions, or extreme conditions, the availability of subsidized, flexible transportation can help support access to medical services, essential destinations, and safe travel alternatives. The program contributes to NVTA’s broader mission of maintaining mobility, accessibility, and continuity of transportation services for vulnerable populations.
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Shared Vehicle Program
The Shared Vehicle Program is a specialized mobility initiative administered by the Napa Valley Transportation Authority (NVTA) to support nonprofit and public organizations that provide services to elderly individuals and persons with disabilities. The program was established to expand transportation capacity within Napa County by allowing qualified 501(c)(3) organizations to access NVTA-owned vehicles for client transportation needs. This approach enables community-based organizations to deliver essential mobility services without incurring the capital costs associated with vehicle acquisition and long-term fleet maintenance.
Eligibility for the program is limited to nonprofit, public, or 501(c)(3) organizations that provide services specifically for seniors or individuals with disabilities. Participating agencies are responsible for supplying qualified drivers and covering operational expenses such as fuel. Drivers must be identified through the borrowing agency’s workers’ compensation policy, and while not strictly required in all cases, possession of a Class B driver license is strongly encouraged due to vehicle classifications. Borrowing agencies must also maintain appropriate insurance coverage, including general liability and hired and non-owned auto liability insurance, with NVTA named as an additional insured.
NVTA’s responsibilities within the program focus on safety, compliance, and fleet management. The agency conducts background checks and drug testing for designated drivers, verifies workers’ compensation coverage, and provides driver training upon successful completion of screening requirements. Once approved, drivers are added to NVTA’s vehicle insurance coverage. NVTA also assumes responsibility for vehicle maintenance, ensuring that shared fleet assets remain safe, reliable, and operationally sound.
Following driver approval and training, participating organizations may schedule vehicle use based on program availability. Borrowing agencies are responsible for vehicle pickup and return, trip documentation, and replacement of fuel used during operations. By leveraging shared public resources, the program enhances transportation accessibility, strengthens partnerships with community service providers, and supports mobility for populations with access and functional needs.
Vinego Paratransit Service
VineGo is the NVTA Americans with Disabilities Act (ADA)-compliant paratransit service, providing shared-ride, curb-to-curb transportation for individuals who are unable to use the regular Vine fixed-route bus system due to physical or cognitive limitations. The service operates within three-quarters of a mile of the fixed-route network and offers scheduled rides that can be booked up to seven days in advance; sameday trips may also be arranged depending on availability.
Eligibility for VineGo is determined on a case-by-case basis and requires applicants to complete an ADA paratransit application and telephone assessment. Once certified, riders can schedule shared rides from their homes to destinations within the service area, with drivers potentially picking up or dropping off other passengers along the route, as typical for ADA paratransit services.
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The service is intended to maintain independence and mobility for riders who cannot independently access or use fixed-route transit due to disability. Fares are set in accordance with ADA guidelines and generally reflect no more than twice the adult cash fare of regular Vine service. VineGo also accommodates ADAeligible visitors from outside Napa, allowing temporary use of the service under specific conditions.
For those interested in applying, eligibility begins with an application submitted to NVTA’s Paratransit Eligibility Office, followed by a telephone interview and assessment, with the option to appeal eligibility decisions if necessary.
Vine Transit Maintenance Facility
The Vine Transit Maintenance Facility is a major capital infrastructure project developed by the NVTA to support the long-term operational, maintenance, and resiliency needs of Vine Transit. Completed in March 2024 after breaking ground in February 2022, the approximately 28,000-square-foot facility is located on an eight-acre site on Sheehy Court in Napa. The project was undertaken to replace Vine Transit’s former leased maintenance yard, which was identified as functionally deficient and incapable of supporting existing operations or future system expansion.
Figure 11-2: VineGo Paratransit Shuttle
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The state-of-the-art facility provides modernized maintenance, administration, and fleet support capabilities, including multiple maintenance bays, a bus wash, expanded vehicle parking, and infrastructure designed to accommodate zero-emission fleet technologies. The facility was constructed with futurefocused design considerations, including provisions for hydrogen fueling and electric vehicle charging capacity, supporting Vine Transit’s transition toward a zero-emission fleet. In addition to operational functions, the site also serves as a backup emergency operations center, enhancing regional transportation resilience and continuity during hazard events.
Funded through a combination of federal, state, and local sources, the approximately $39 million project was designed with environmentally sustainable materials and regulatory compliance under the California Environmental Quality Act (CEQA). The Vine Transit Maintenance Facility represents a critical investment in transportation system reliability, operational efficiency, workforce support, and hazard resilience, positioning NVTA to maintain and expand transit service for decades to come.
GETAC Tablets
NVTA can internally radio its drivers or use the GETAC tablet on the bus to talk to drivers if there was an emergency. NVTA could also manage any route deviations/detours on our CAD/AVL system that would then publish to third party applications (such as Google Maps or the Transit App) that ingest its General Transit Feed Specification Real Time Feed. NVTA would also have an representative in the EOC working under the operations branch that would be receive up-to-date information on the street network that could then be Figure 11-3: Ribbon Cutting new at the new Vine Transit Maintenance Facility CAL OES SUBMITTAL - JUNE 2026
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communicated downstream to customer service representatives, drivers, dispatchers and operations managers.
Vine UpValley Link Program
To address transportation gaps identified through the 2025 Accessible Transportation Needs Assessment (ATNA), NVTA launched the Vine UpValley Link Program on July 1, 2026. The program was developed to expand mobility options for seniors and individuals with disabilities living in the upper Napa Valley communities of Yountville, St. Helena, and Calistoga, particularly for trips that extend beyond the traditional Vine Transit service area. The program directly supports ATNA recommendations to expand non-transit transportation options and improve access to essential destinations, including healthcare facilities such as St. Helena Hospital.
Vine UpValley Link functions as a subsidized transportation assistance program utilizing transportation network companies (TNCs) such as Uber and Lyft. Eligible participants include residents of Yountville, St.
Helena, and Calistoga who are 65 years of age or older, ADA-certified, or disabled regardless of age. Through a reloadable payment card system, participants may contribute up to $50 per month, which is matched by NVTA, providing up to $100 in monthly transportation assistance. The program is designed to supplement existing transit services by providing flexible transportation for medical appointments, essential services, destinations not directly served by transit, and trips occurring when fixed-route or shuttle services are unavailable.
The Vine UpValley Link Program complements NVTA’s existing mobility services, including VineGo Paratransit, Taxi Scrip, and the Shared Vehicle Program, further expanding the agency’s portfolio of transportation solutions for vulnerable and transportation-dependent populations throughout Napa County.
11.5 Risk Assessment
This section focuses on profiling hazards specific to NVTA 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 district, and information on district-specific differences in hazard vulnerability across the planning area. It also identifies total district assets at risk, including people, property, and critical facilities and infrastructure within the district. 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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11.5.1 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.
NVTA’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 district. Table 11-9 provides a crosswalk of hazards identified in select planning documents, including the 2020 Napa County MJHMP, 2021 MTC MMP, 2025 CBTP, other planning documents 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 NVTA and which ones were not.
The internal planning group then ranked hazards based on their probability of affecting NVTA and potential impacts on the community. Figure 11-4 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 district’s vulnerability to specifically identified hazards.
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Table 11-9: NVTA Document Review of Potential Hazards
Hazard 2020 Napa County
MJHMP 2021 MTC MJHMP 2023 CaliforniaSHMP
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 11-4: NVTA 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 11-4. Table 11-10 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 11-10: NVTA Hazards Prioritization Summary
Hazard Priority Explanation
Earthquake / Liquefaction High Profiled in Volume 1, Section 3.3.4, and Section 11.5.2.2 in this annex (not including Liquefaction due to low probability and impact potential) Wildfire Extreme Profiled in Volume 1, Section 3.3.1, and Section 11.5.2.1 in this annex Flood High Profiled in Volume 1, Section 3.3.2, and Section 11.5.2.3 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 -
Profiled in Volume 1, Section 3.3.5; not a priority due to being outside jurisdictional mission and authority, but Heavy Rain discussed as a compounding hazard to Flood
Drought -
Profiled in Volume 1, Section 3.3.6; not a priority due to being outside jurisdictional mission and authority
Geologic / Mass Movement Medium Profiled in Volume 1, Section 3.3.5, and Section 11.5.2.4 in this annex as Slope Failure
Extreme Heat High Profiled in Volume 1, Section 3.3.8, and Section 11.5.2.5 in this annex Agricultural Pests -
Profiled in Volume 1, Section 3.3.9; not a priority due to being outside jurisdictional mission and authority
Sea Level Rise -
Profiled in Volume 1, Section 3.3.9; not a priority due to low probability and impact potential
Climate Change High Profiled in Volume 1, Section 3.3.9, and Section 11.5.2.6 in this annex and discussed as a compounding hazard in relevant profiles
Dam Failure -
Profiled in Volume 1, Section 3.3.3; not a priority due to low probability and impact potential
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11.5.2 Vulnerability to Specific Hazards
Assessing vulnerabilities exposes the unique characteristics of individual hazards and begins the process of narrowing down which areas within the district 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 district’s planning group estimated vulnerable populations, properties, and assets, and potential losses. In addition, the exposure of district assets to drought, earthquake, wildfire, flood, and climate change hazards were also considered.
Many of the hazard profiles include a snapshot map and damage estimation tables that illustrate the district’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 six hazards for the NVTA.
Wildfire
SECTION 11.5.2.1
Earthquake
SECTION 11.5.2.2
Flood
SECTION 11.5.2.3
Slope Failure
SECTION 11.5.2.4
Extreme Heat
SECTION 11.5.2.5
Climate Change
SECTION 11.5.2.5
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Wildfire Hazard
Wildfire represents one of the most significant natural hazards affecting Napa County and the transportation systems operated and supported by NVTA. The County’s climate, vegetation patterns, and topographic conditions combine to create an environment highly conducive to wildfire ignition and rapid fire spread. Hot, dry summers, extended drought cycles, and periodic extreme wind events contribute to elevated fire risk across both rural and developed areas. Climate change has further intensified these conditions by increasing temperatures, reducing fuel moisture, and lengthening wildfire seasons throughout California.
Wildfire hazards present multiple direct and indirect risks to NVTA’s transportation network as shown in Figure 11-5 and summarized in Table 11-11 and Table 11-12. Fire events may disrupt roadway access, damage transportation infrastructure, reduce visibility, and degrade air quality. Critical transportation corridors, including state highways and local arterial routes, may be subject to temporary closures, traffic congestion, or restricted operations during wildfire incidents. Because Napa County’s circulation patterns are strongly corridor-dependent, disruptions affecting key routes can significantly affect regional mobility, emergency response, and evacuation efficiency.
Transit operations are particularly sensitive to wildfire-related impacts. Smoke conditions may create hazardous operating environments, affecting driver safety, vehicle performance, and passenger health.
Reduced air quality can present serious health risks, especially for vulnerable populations such as seniors, individuals with disabilities, and persons with pre-existing respiratory conditions. Wildfire events may also disrupt fueling infrastructure, power supply systems, communications networks, and maintenance facilities, all of which are essential for maintaining service continuity.
Wildfire-related evacuations represent a critical operational consideration. Transportation networks serve a vital lifeline function during emergency evacuations, supporting both population movement and emergency response activities. Increased traffic volumes, congestion, and rapidly changing conditions may affect transit routing, scheduling, and system reliability. Transit-dependent populations may rely heavily on public transportation services when private vehicle access is limited or unavailable.
Wildfire hazards may also produce longer-term system impacts. Damage to roadway infrastructure, traffic control systems, communications equipment, and electrical supply networks can lead to extended service disruptions. Post-fire conditions, including debris flows, slope instability, and erosion, may further affect transportation corridors and infrastructure reliability, particularly during subsequent storm events.
NVTA’s exposure to wildfire risk is influenced by regional land use patterns and development trends. Much of Napa County includes wildland-urban interface (WUI) areas where development and fire-prone landscapes intersect. Transportation corridors frequently traverse these environments, increasing the likelihood that wildfire events may affect roadway operations and transit services.
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Table 11-11: NVTA Facilities Wildfire Exposure
Lifelines (miles) - Wildfire Severity Zone
Infrastructure Type
(Linear)
SRA
Very
High
LRA
Very
High
Very High Total SRA High LRA High High Total SRA
Moderate
LRA
Moderate
Moderate
Total
Bus Route 0.23 - 2.34 5.44 - 69.70 9.82 - 66.77
Table 11-12: NVTA Linear Infrastructure Wildfire Exposure Critical Infrastructure - Wildfire Severity Zone
Infrastructure Type
SRA
Very
High
LRA
Very
High
Very High Total SRA High LRA High High Total SRA
Moderate
LRA
Moderate
Moderate
Total
Bus Stop - - - - 11 11 - 13 13
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Figure 11-5: NVTA Wildfire Risk
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Earthquake Hazard
Earthquake hazards represent a significant risk within Napa County due to the region’s location within one of the most seismically active areas in the United States. The County is influenced by several active fault systems, including the West Napa Fault, which was responsible for the 2014 South Napa earthquake. This event highlighted the region’s vulnerability to seismic activity and demonstrated the potential for widespread infrastructure damage, transportation disruptions, and prolonged recovery impacts.
Seismic events pose both direct and indirect risks to NVTA’s transportation network and transit operations and shown in Figure 11-6 and Figure 11-7 and summarized in Table 11-13, Table 11-14, Table 11-15, and Table 11-16. Ground shaking may damage roadways, bridges, overpasses, traffic control systems, utilities, and transit facilities. Even moderate earthquakes can produce pavement cracking, surface deformation, and structural stress affecting transportation corridors. Damage to bridges and elevated structures is of particular concern, as Napa County’s circulation patterns are heavily dependent on a limited number of regional corridors and crossing points.
Transit operations are highly sensitive to earthquake-related disruptions. Seismic events may impair roadway accessibility, disrupt fueling and power systems, damage maintenance facilities, and affect communications infrastructure necessary for service coordination. Vehicle operations may be temporarily suspended due to safety concerns, debris, structural assessments, or traffic management requirements.
Extended service interruptions can have disproportionate consequences for transit-dependent populations.
Secondary hazards associated with earthquakes may further affect transportation systems. Ground failure, including liquefaction, lateral spreading, and settlement, may occur in areas with susceptible soil conditions. These effects can damage pavement sections, undermine roadway, embankments, and structural foundations. Landslides and slope failures may also occur in hillside and mountainous areas, potentially blocking roadways and isolating portions of the network.
Earthquake hazards may produce cascading system impacts. Damage to electrical infrastructure, communications systems, and fuel supply networks can affect transit service continuity even where roadway damage is limited. Emergency response activities and post-event inspections may introduce operational constraints, contributing to congestion and service delays.
Napa County’s transportation network includes several critical facilities and corridors that play an essential role during emergency response and recovery. Transportation systems serve as lifeline infrastructure following seismic events, supporting emergency services, medical response, damage assessment, and community recovery. Maintaining operational flexibility and system redundancy is therefore central to NVTA’s hazard planning framework.
The County’s built environment includes infrastructure of varying age and design standards, which influences seismic vulnerability. Older bridges, roadways, and facilities constructed under previous building codes may exhibit increased susceptibility to damage. Seismic retrofits, modernization efforts, and stateof-good-repair investments represent important mitigation strategies for reducing these risks.
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Table 11-13: NVTA Facilities Earthquake Risk (M7.1 Hunting Creek–Berryessa) Lifelines (miles) - M7.1 Hunting Creek Berryessa
Infrastructure Type (Linear) VIII - Severe VII - Very Strong VI - Strong V - Moderate Bus Route - 198.2 283.9 -
Table 11-14: NVTA Linear Assets Earthquake Risk (M7.1 Hunting Creek–Berryessa) Lifelines (miles) - M7.1 Hunting Creek Berryessa
Infrastructure Type VIII - Severe VII - Very Strong VI - Strong V - Moderate Bus Stop - 148 108 -
Table 11-15: NVTA Facilities Earthquake Risk (M6.7 West Napa) Lifelines (miles) - M6.7 West Napa
Infrastructure Type (Linear) V-Moderate VI-Strong VII-Very Strong VIII-Severe Bus Route 2.2 81.9 115.8 282.2
Table 11-16: NVTA Linear Assets Earthquake Risk (M6.7 West Napa) Critical Infrastructure - M6.7 West Napa
Infrastructure Type VIII - Severe VII - Very Strong VI - Strong V - Moderate Bus Stop 194 42 20 -
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Figure 11-6: NVTA Earthquake Risk (M7.1 Hunting Creek–Berryessa) CAL OES SUBMITTAL - JUNE 2026
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Figure 11-7: NVTA Earthquake Risk (M6.7 West Napa)
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Flood Hazard
Flooding represents a recurring and operationally significant hazard within Napa County, driven by seasonal precipitation patterns, watershed dynamics, and the geographic characteristics of the Napa River system. Unlike low-frequency hazards such as major earthquakes, flood events occur with greater regularity and can produce both localized and widespread impacts to transportation infrastructure and transit operations supported by NVTA.
Flood hazards in Napa County are primarily associated with riverine flooding, stormwater runoff, and localized drainage issues. Periods of intense rainfall, atmospheric river events, and saturated soil conditions can cause waterways to exceed channel capacity, resulting in overbank flooding. Urban and suburban flooding may also occur when stormwater systems are overwhelmed or when drainage pathways are obstructed. Low-lying areas, roadway underpasses, and corridors adjacent to waterways are particularly vulnerable.
Flooding poses direct risks to transportation networks by impairing roadway accessibility, damaging pavement structures, and disrupting traffic operations. Standing water, debris deposition, erosion, and slope instability may render roadways unsafe or impassable. Even relatively minor flood events can require temporary lane closures, detours, or traffic control measures. Because Napa County’s circulation system relies heavily on key corridors and limited routing alternatives, flood-related disruptions can significantly affect regional mobility.
Transit operations are especially sensitive to flood conditions. Flooded roadways may force route deviations, schedule delays, or temporary service suspensions. Reduced visibility, hydroplaning risks, and debris hazards can affect vehicle safety and operational reliability. Flooding may also impact transitsupporting infrastructure, including maintenance facilities, electrical systems, communications equipment, and fueling or charging infrastructure.
Flood hazards frequently generate cascading impacts. Roadway closures may increase congestion on unaffected routes, complicate emergency response, and disrupt evacuation or re-entry movements. Damage to utilities, including electrical and communications systems, may further affect transit operations even where physical roadway damage is limited.
Napa County’s flood risk is influenced by hydrologic variability and climate trends. While seasonal rainfall patterns are characteristic of the region, climate change is expected to increase the intensity and variability of storm events. More concentrated precipitation may elevate the likelihood of flash flooding, drainage system exceedance, and infrastructure stress. Post-wildfire conditions may further amplify flood risk by increasing runoff rates, debris flows, and erosion.
From a transportation perspective, flooding represents both an infrastructure and operational hazard.
Impacts may include pavement deterioration, roadway subgrade weakening, signal system disruptions, and reduced corridor reliability. Transit-dependent populations may experience disproportionate effects when service interruptions limit access to employment, healthcare, and essential services.
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Climate Change & Severe Weather
Climate change functions as a risk multiplier for severe weather hazards. Rising temperatures can increase the severity of severe weather events, while shifts in precipitation patterns may intensify storm impacts.
These trends introduce growing uncertainty into transportation system performance and operational reliability.
Heavy precipitation events may produce localized flooding, roadway ponding, and drainage exceedance.
High winds may affect vehicle stability, increase debris hazards, and disrupt operations. While these events are often short in duration, they may generate immediate operational constraints and safety concerns.
Severe weather events may also disrupt transit operations through secondary impacts. Electrical infrastructure strain, Public Safety Power Shutoff (PSPS) events, and localized equipment failures may affect communications systems, charging infrastructure, fare systems, and facility operations. High temperatures combined with wildfire smoke conditions may further degrade air quality, amplifying health risks for passengers and operators.
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Figure 11-8: NVTA Flood Risk (FEMA and DWR Awareness Zones) CAL OES SUBMITTAL - JUNE 2026
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Table 11-17: NVTA Linear Asset in FEMA Flood Zones
Lifelines (miles) - Flood Risk Exposure
Infrastructure Type (linear) Flood Fringe Floodway 100-YR Total 500-YR sans 100-YR Grand Total Bus Route 64.7 9.0 73.7 20.7 94.4
Table 11-18: NVTA Facilities in FEMA Flood Zones
Critical Infrastructure (points) - Flood Risk Exposure
Infrastructure Type Flood Fringe Floodway 100-YR Total 500-YR sans 100-YR 500-YR Total Bus Stop 31 7 38 14 52
Slope Failure Hazard
Slope failure represents a localized but potentially high-consequence hazard within Napa County, particularly in areas characterized by steep terrain, hillside development, and transportation corridors traversing mountainous or sloping landscapes. Slope failures encompass a range of ground movement processes, including landslides, debris flows, rockfalls, and soil slumps, all of which may affect roadway stability, infrastructure integrity, and transit operations supported by NVTA.
Slope failures are typically triggered by a combination of environmental and geologic factors. Intense or prolonged rainfall is one of the most common initiating mechanisms, as soil saturation reduces slope stability and increases the likelihood of mass movement. Seismic activity may also trigger slope failures by destabilizing soils and fractured rock formations. Wildfire events can further amplify risk by removing vegetation, altering soil properties, and increasing runoff rates, thereby elevating susceptibility to post-fire debris flows and erosion.
Transportation networks are particularly vulnerable to slope failure hazards due to their frequent alignment along hillsides, cut slopes, and canyon corridors. Ground movement may result in roadway blockage, pavement deformation, embankment instability, and structural damage to retaining systems, bridges, culverts, and drainage infrastructure. Rockfalls and debris deposition may create sudden safety hazards, while larger slope failures may produce extended closures and costly repairs.
Napa County’s geography includes numerous hillside and mountainous areas where slope stability concerns are inherent. Rural and regional transportation corridors often traverse terrain susceptible to landslides and debris flows, particularly during heavy storm events. Localized slope failures may isolate portions of the roadway network, reduce routing alternatives, and complicate emergency response or evacuation movements.
Transit operations are sensitive to slope failure impacts because even small-scale events may disrupt service continuity. Roadway obstructions, unstable slopes, and debris hazards may necessitate route deviations, delays, or temporary suspensions. Secondary impacts, including drainage system damage CAL OES SUBMITTAL - JUNE 2026
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and erosion, may prolong operational disruptions. Corridor-dependent travel patterns may further magnify the consequences of localized failures. The exposure of NVTA facilities and assets are shown in Figure 11-9 and summarized in Table 11-19 and Table 11-20.
Slope failure hazards often produce cascading effects. Blocked roadways may increase congestion on alternate routes, affect emergency vehicle access, and disrupt passenger mobility. Damage to drainage infrastructure may exacerbate flooding risks, while repeated slope instability may require long-term stabilization measures.
Climate variability plays an important role in slope failure risk. Changes in precipitation intensity, including more concentrated storm events, may increase soil saturation, runoff rates, and erosion potential. Post-wildfire conditions may significantly elevate debris flow risks, particularly during the first major rainfall events following fire incidents.
Table 11-19: NVTA Linear Assets in Landslide Susceptibility Zones Lifelines (miles) - Landslide Susceptibility
Infrastructure Type (Linear) High Moderate Low
Bus Route 2.1 37.0 13.6
Table 11-20: NVTA Facilities in Landslide Susceptibility Zones Critical Infrastructure - Landslide Susceptibility
Infrastructure Type High Moderate Low
Bus Stop - 11 3
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Figure 11-9: NVTA Landslide Susceptibility
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Extreme Heat Hazard
Extreme heat hazards in Napa County can affect transportation infrastructure, transit operations, and passenger safety. These hazards most commonly include extreme heat, heavy precipitation events, high winds, and storm-related disruptions. Among these, extreme heat represents one of the most operationally significant and increasingly frequent hazards affecting NVTA.
Extreme heat events are characterized by prolonged periods of elevated temperatures that exceed historical seasonal norms. Climate projections for California indicate rising average temperatures, more frequent heatwaves, and longer-duration extreme heat events. These conditions can impose both direct and indirect stresses on transportation systems. High temperatures accelerate pavement deterioration, increase thermal expansion of roadway materials, and strain vehicle mechanical systems. Transit vehicles, facilities, and supporting infrastructure may experience increased cooling demands, reduced operational efficiency, and higher maintenance requirements.
Extreme heat presents critical health and safety concerns for transit-dependent populations. Passengers waiting at bus stops, particularly those without shade or cooling access, may be exposed to hazardous conditions. Vulnerable populations, including seniors, individuals with disabilities, and persons with preexisting medical conditions, face heightened risk of heat-related illness. Paratransit riders may be especially sensitive due to underlying health vulnerabilities and longer trip durations. Heat exposure risks may be compounded during service delays, vehicle breakdowns, or power disruptions.
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 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).
According to Cal-Adapt, NVTA will likely experience a climate change-driven increase in extreme heat days above 98.6°F from four days per year to 22 days per year by the end of the century under a medium emissions scenario (RCP 4.5). Over the same time period, NVTA is also likely to see an increase in warm nights above
59.5°F from five per year to 39.
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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).
Climate change represents a long-term, cross-cutting hazard that influences the frequency, intensity, and duration of multiple natural hazards affecting Napa County and the transportation systems operated and supported by NVTA. Unlike discrete hazard events, climate change functions as a risk multiplier that amplifies existing environmental stresses such as wildfire, flooding, extreme heat, drought, and severe storms. These changes introduce increasing uncertainty for transportation planning, infrastructure durability, and transit operations.
Projected climate trends for Northern California indicate rising average temperatures, more frequent extreme heat events, longer wildfire seasons, and greater variability in precipitation patterns. These conditions are expected to increase the likelihood of both drought and intense storm events, which can affect transportation infrastructure in different ways. Prolonged heat may accelerate pavement degradation, increase vehicle maintenance needs, and elevate operational costs. Conversely, more intense rainfall events may overwhelm drainage systems, contribute to flooding and erosion, and destabilize slopes along transportation corridors.
For NVTA, climate change poses both infrastructure and operational risks. Transportation systems are particularly sensitive to changing environmental conditions because they depend on reliable roadway networks, electrical infrastructure, communications systems, and fuel or charging supply chains. Extreme heat may stress vehicle systems and passenger environments, while wildfire smoke events may degrade air quality and disrupt service operations. Increased precipitation intensity may lead to roadway closures, transit detours, and safety concerns for vehicle operations.
Climate change also increases exposure to compound hazards, where multiple hazards occur simultaneously or sequentially. For example, wildfire events followed by heavy rainfall may trigger debris flows or slope failures along transportation corridors. Similarly, extreme heat events combined with power disruptions may affect transit facility operations, vehicle charging infrastructure, and passenger safety.
Transportation-dependent populations may face disproportionate impacts from climate-related hazards.
Seniors, individuals with disabilities, low-income residents, and persons without access to private vehicles often rely on public transit systems for daily mobility. These populations may be particularly vulnerable during extreme heat events, wildfire smoke conditions, or service disruptions that limit access to cooling centers, healthcare facilities, and essential services.
Climate change considerations are increasingly integrated into transportation planning and infrastructure investment decisions. NVTA’s planning documents emphasize sustainability, emissions reduction, and transition toward zero-emission transit fleets. Investments in electrification infrastructure, multimodal transportation options, and resilient transit facilities help address both climate mitigation and climate adaptation objectives.
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11.5.3 Climate Change Impacts & Vulnerable Populations
Climate change is expected to amplify existing natural hazards within Napa County, intensifying the frequency, severity, and duration of events that directly affect transportation systems and the populations served by the NVTA. Rising temperatures, altered precipitation patterns, prolonged drought conditions, and increasing wildfire intensity represent some of the most significant climate-driven stressors influencing regional risk conditions. These environmental changes introduce both physical infrastructure challenges and social vulnerability considerations.
Projected increases in extreme heat events may affect transportation infrastructure performance, transit operations, and passenger safety. Elevated temperatures can accelerate pavement deterioration, strain vehicle systems, and increase cooling demands within transit vehicles and facilities. Heat exposure also presents health risks for transit-dependent individuals, particularly older adults, persons with disabilities, and individuals with pre-existing medical conditions. Prolonged heat events combined with power disruptions may further complicate mobility for populations reliant on electrically powered systems.
Wildfire risk represents one of the most visible climate-related hazards affecting Napa County. Climate projections indicate longer fire seasons, drier fuels, and more extreme fire behavior. Wildfire events may disrupt roadway networks, reduce air quality, interrupt power supply, and impede transit operations.
Vulnerable populations, including senior citizens, individuals with disabilities, low-income households, and residents without access to private vehicles, may face disproportionate challenges during wildfire incidents. These groups may have fewer evacuation options, heightened sensitivity to smoke exposure, and greater reliance on public transportation systems for emergency mobility.
Changes in precipitation intensity and variability may also increase flooding risks, debris flows, and erosion-related impacts. Even where long-term precipitation totals remain stable, more concentrated storm events can overwhelm drainage systems and damage transportation infrastructure. Flood-related disruptions may affect roadway access, transit routes, and service continuity. Vulnerable populations may experience compounded impacts when mobility interruptions limit access to employment, healthcare, and essential services.
Climate change can also exacerbate underlying social vulnerabilities. Individuals with limited financial resources may have reduced capacity to adapt to rising transportation costs, relocate from hazard-prone areas, or invest in protective measures. Older adults and persons with disabilities may face greater sensitivity to environmental stressors such as heat, smoke, and service disruptions. Households without reliable vehicle access may depend heavily on transit systems during emergencies, increasing the importance of system resilience.
Environmental conditions influenced by climate change may further affect public health, which in turn influences mobility needs. Poor air quality from wildfire smoke, extreme heat exposure, and disruptions to medical or social services may increase transportation demand for vulnerable populations. Transit systems CAL OES SUBMITTAL - JUNE 2026
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frequently serve as lifeline services under these conditions, supporting evacuation, access to cooling centers, healthcare facilities, and essential destinations.
11.5.4 Hazard Problem Statements
As part of the mitigation action identification process, the Planning Committee 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 11-21. 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 11-23 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 11-21 and Table 11-23 Table 11-21: NVTA Hazard Problem Statements
Problem
No.
Hazard Area of
Concern
Primary
Agency
Problem Description Related MA
ps-AH-NVTA002All Hazard Threat Napa Valley
Transportation
Authority
NVTA lacks a formal Continuity of
Operations Plan to address post-disaster
disruptions to bus service and operations.
ma-AH-NVTA001
ps-AH-NVTA333All Hazard Threat Napa Valley
Transportation
Authority
Although NVTA's most critical facilities
have backup generators, they are
vulnerable to prolonged power outages
caused by extreme heat, PSPS, and storm
events, which severely reduce bus charging
and operational capacity.
ma-WF-NVTA002
ps-CC-NVTA001Climate
Change
Threat Napa Valley
Transportation
Authority
Increasing frequency and severity of
climate change-driven hazards such as
extreme heat and wildfire threaten
infrastructure, assets, and users, and
compound other operational risks.
ma-AH-NVTA001, ma-CCNVTA-001, maFL-NVTA-001,
ma-SW-NVTA001, ma-WFNVTA-001
ps-EQ-NVTA001Earthquake Impact Napa Valley
Transportation
Authority
Earthquake-related damage to key
roadways and bridges could severely
disrupt bus routes and paratransit services,
limiting access to essential destinations
and delaying response.
ma-AH-NVTA001, ma-AHNVTA-002
ps-EQ-NVTA334Earthquake Impact Napa Valley
Transportation
Authority
A major earthquake could disrupt power
and communication systems, cutting off
communication between operations and
drivers.
ma-AH-NVTA001, ma-WFNVTA-002, maAH-NVTA-002
ps-FL-NVTA001Flood Threat Napa Valley
Transportation
Authority
Flooding threatens 30 bus stops and 73
miles of routes.
ma-AH-NVTA002, ma-FLNVTA-001
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Problem
No.
Hazard Area of
Concern
Primary
Agency
Problem Description Related MA
ps-FL-NVTA002Flood Victim Napa Valley
Transportation
Authority
Flooding of the 3rd Street Bridge and
Highway 29 would isolate low-income
communities from critical transit services.
ma-AH-NVTA002, ma-CCNVTA-001, maFL-NVTA-001
ps-SW-NVTA001High Heat Victim Napa Valley
Transportation
Authority
Heatwaves can disrupt service and
threaten the health of paratransit riders
and other transit-dependent populations.
ma-AH-NVTA002, ma-CCNVTA-001, maSW-NVTA-001,
ma-WF-NVTA001
ps-SW-NVTA002High Heat Impact Napa Valley
Transportation
Authority
Bus stops have insufficient shelters to
protect waiting riders from extreme heat,
especially during prolonged service delays
or if the GTFS Real Time Feed is out.
ma-SW-NVTA001
ps-SW-NVTA003High Heat Threat Napa Valley
Transportation
Authority
Extreme heat events can strain the
regional power grid, increasing the risk of
prolonged outages. Backup power at key
facilities may be insufficient to maintain
operations during these peak demand
periods.
ma-WF-NVTA002
ps-SF-NVTA001Slope Failure Threat Napa Valley
Transportation
Authority
Landslide-prone road segments in hillside
and rural areas threaten route continuity
and driver and passenger safety, especially
during or after heavy rain events.
ma-AH-NVTA001, ma-FLNVTA-001, maAH-NVTA-002,
ma-CC-NVTA001
ps-SF-NVTA002Slope Failure Impact Napa Valley
Transportation
Authority
Slope failures along routes can damage
transportation infrastructure, causing
delays, costly repairs or temporary service
cancellations.
ma-AH-NVTA001, ma-FLNVTA-001, maAH-NVTA-002
ps-WF-NVTA001Wildfire Threat Napa Valley
Transportation
Authority
Bus routes traverse high wildfire risk areas,
threatening infrastructure, busses, riders
and drivers from both direct and indirect
impacts such as road blocks and smoke.
ma-AH-NVTA001, ma-AHNVTA-002, maCC-NVTA-001,
ma-WF-NVTA001
ps-WF-NVTA002Wildfire Victim Napa Valley
Transportation
Authority
Wildfire smoke poses health risks to
passengers and drivers due to inadequate
ventilation systems on busses.
ma-AH-NVTA002, ma-WFNVTA-001
ps-WF-NVTA003Wildfire Impact Napa Valley
Transportation
Authority
Wildfires and red flag warning days trigger
PSPSs, jeopardizing electric bus charging
capacity and limiting NVTA?s ability to
maintain service continuity.
ma-WF-NVTA002
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11.6 Mitigation Strategy
This section provides the framework for how NVTA 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 district’s prioritized mitigation actions. Together, these elements demonstrate how NVTA 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 NVTA, the strategy outlined in this annex reflects the outcomes of the countywide planning process while also addressing the district’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 wildfire, earthquakes, flooding, slope failure, and extreme heat.
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 district, county, and regional planning mechanisms. Each action identifies responsible parties, potential funding sources, and the resources needed for implementation.
For NVTA, this strategy provides a framework for strengthening resilience by combining district-led initiatives, such as infrastructure improvements, and community preparedness, with regional coordination through the MJHMP. By advancing these efforts in alignment with the Strategic Plan and other local planning documents, NVTA 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 11.6.1, Capabilities and Opportunities, provides a summary of NVTA’s capacity to address natural hazards.
▪ Section 11.6.2, Mitigation Action Plan, presents the authority’s prioritized actions to guide implementation in coordination with countywide strategies. ▪ Section 11.6.3, 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 NVTA’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 NVTA’s capabilities across four areas: planning and regulatory, administrative and technical, fiscal, and education and outreach. This overview highlights the tools and CAL OES SUBMITTAL - JUNE 2026
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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.
11.6.1 Capabilities & Opportunities
This section provides a detailed assessment of Napa Valley College’s current capabilities to support hazard mitigation, as well as future opportunities. This consists of describing how the college is planning for hazards and growth and a summary of its existing capabilities and the potential for enhancement.
Planning for Hazards & Growth
NVTA operates at the intersection of two closely related planning imperatives: accommodating long-term growth in travel demand while ensuring that the transportation system remains reliable and functional under hazard conditions. Napa County’s transportation network is shaped by geographic constraints, corridor-dependent travel patterns, and exposure to multiple natural hazards, including wildfire, flooding, earthquake, and extreme weather. As a result, NVTA’s planning framework inherently integrates considerations of both system capacity and system resilience.
NVTA’s long-range planning efforts, most notably the CTP, provide the primary mechanism for aligning transportation investments with projected growth trends and evolving risk conditions. The CTP establishes policies and performance objectives that emphasize corridor reliability, multimodal connectivity, safety, and operational efficiency. These objectives support not only routine mobility needs but also hazard-related priorities, such as maintaining viable evacuation routes, reducing congestion during emergencies, and minimizing the consequences of infrastructure disruptions. By evaluating land use patterns, travel forecasts, and infrastructure conditions, the CTP guides investments that address future demand while reducing system vulnerabilities.
Short-range planning further supports adaptive capacity. The Short-Range Transit Plan (SRTP) identifies near-term capital improvements, fleet investments, and operational strategies necessary to maintain service reliability within a dynamic operating environment. Because transit systems are particularly sensitive to disruptions involving roadway closures, power supply interruptions, and extreme environmental conditions, the SRTP functions as an important resilience planning tool. Investments in fleet modernization, electrification infrastructure, facility upgrades, and communications systems contribute to both operational performance and hazard readiness.
Hazard planning considerations are reinforced through NVTA’s participation in regional hazard mitigation efforts. As a participating agency in the Metropolitan Transportation Commission’s Multi-Jurisdictional Hazard Mitigation Plan (MJHMP), NVTA contributes to regional risk assessments, critical facility inventories, and mitigation strategy development. This coordination ensures that transportation-related vulnerabilities, including corridor dependencies, facility exposures, and operational risks, are evaluated within a broader, multi-hazard planning context. Integration of hazard data into transportation decisionmaking supports investments that enhance infrastructure durability, improve system redundancy, and reduce failure risks.
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Growth trends and hazard conditions are closely interrelated. As development patterns evolve and travel demand increases, pressure on key transportation corridors may intensify, potentially amplifying the consequences of hazard-related disruptions. Congestion, limited routing alternatives, and infrastructure constraints may affect evacuation efficiency, emergency response, and system recovery. NVTA’s planning framework addresses these challenges by prioritizing projects that improve corridor performance, enhance multimodal alternatives, and strengthen network connectivity. Multimodal investments, including transit, bicycle, and pedestrian infrastructure, increase system flexibility and provide additional mobility options during both routine and emergency conditions.
Funding mechanisms such as Measure U further support integrated planning for hazards and growth. By providing jurisdictions with expanded financial flexibility, bonding authority, and eligibility for a broader range of transportation improvements, Measure U enables accelerated delivery of infrastructure projects that address deferred maintenance, congestion, safety, and emergency mobility needs. These investments yield important resilience co-benefits by reducing infrastructure deterioration, improving operational reliability, and enhancing corridor performance under stress.
Development & Hazard Considerations
Land use and development patterns within Napa County are closely linked to both transportation system performance and hazard vulnerability. NVTA’s planning responsibilities require the agency to evaluate how existing and future development may influence travel demand, infrastructure capacity, and the transportation network’s ability to function during hazard events. Because Napa County’s growth is largely concentrated within established urban areas while much of the surrounding land remains rural or environmentally constrained, development decisions carry important implications for system reliability and resilience.
New development can increase demand on already corridor-dependent transportation networks. As residential, commercial, and mixed-use projects are introduced, traffic volumes, transit ridership, and multimodal travel needs may grow. In hazard-prone environments, increased congestion and limited routing alternatives may amplify the consequences of disruptions caused by wildfire, flooding, seismic events, or severe weather. Transportation corridors that serve as critical evacuation routes may experience operational stress during emergencies, particularly when growth outpaces infrastructure improvements.
Development location is also a key hazard consideration. Projects situated in wildfire-prone areas, floodplains, or locations subject to slope instability may introduce long-term transportation risks. Roadway access, emergency response routes, and transit service reliability may be affected by hazard exposure, infrastructure damage, or environmental constraints. Development in hillside and wildland-urban interface areas, for example, may increase evacuation complexity while placing greater demands on limited roadway networks.
NVTA’s planning framework addresses these interactions through coordination with local jurisdictions, integration of land use forecasts, and alignment of transportation investments with growth patterns. The CTP evaluates projected development trends to prioritize infrastructure improvements that enhance CAL OES SUBMITTAL - JUNE 2026
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corridor performance, safety, and multimodal connectivity. By directing resources toward capacity enhancements, operational improvements, and system modernization, NVTA helps mitigate the transportation impacts associated with growth while reducing vulnerability to disruptions.
Hazard considerations are further integrated through environmental review processes and regulatory frameworks. Development projects are evaluated under the California Environmental Quality Act (CEQA), which requires analysis of environmental impacts, including transportation, emergency access, and hazard-related conditions. These evaluations help identify infrastructure needs, mitigation measures, and design considerations that reduce risk and improve system performance.
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 district’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 NVTA 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.
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Summary of Capabilities & Opportunities
This Capabilities and Opportunities Assessment for NVTA summarizes the various types of capabilities it has for hazard mitigation currently. The assessment also identifies opportunities to integrate, expand, and improve the authority’s capabilities for future hazard mitigation. Table 11-22 provides a comprehensive list of capabilities and identifies the current status, current mitigation use, and future opportunities.
Planning & Regulatory
NVTA’s planning and regulatory capabilities are primarily reflected through its long-range transportation planning, capital programming, and coordination with local, regional, state, and federal partners. While NVTA is not a traditional hazard response agency, many of its core functions support hazard mitigation, system resilience, and continuity of operations.
NVTA’s Capital Improvements Program (CIP), Short-Range Transit Plan (SRTP), and related planning documents provide the primary framework for identifying, prioritizing, and funding resilience-related projects. These include facility upgrades, fleet modernization, infrastructure improvements, state-of-goodrepair investments, and multimodal mobility enhancements. Seismic safety, earthquake modernization, and non-structural improvements are generally addressed through these broader capital planning efforts rather than standalone hazard-specific programs.
NVTA does not maintain agency-specific fire prevention, floodplain response, stormwater management, drought, groundwater, FireWise, or CWPP programs, as these functions generally fall outside its statutory mission and are managed by local jurisdictions, special districts, fire agencies, or emergency management partners. However, NVTA coordinates with these agencies when transit facilities, corridor improvements, evacuation routes, or infrastructure investments intersect with wildfire, flooding, seismic, or other hazard concerns.
Climate adaptation and sustainability planning are among NVTA’s strongest hazard-related capabilities.
Climate action, emissions reduction, zero-emission fleet investments, electrification infrastructure, multimodal transportation options, and air quality programs are embedded throughout the Countywide Transportation Plan, SRTP, and related initiatives. These efforts provide both environmental and resilience benefits by addressing long-term risks associated with extreme heat, wildfire conditions, infrastructure stress, and climate change.
Future integration of the MJHMP will occur through various processes and mechanisms outlined across multiple mitigation actions (Table 11-23). Key opportunities for future hazard mitigation integration with NVTA’s existing planning mechanisms include using the updated risk assessment, projected climate change impacts, and hazard-specific vulnerability findings to inform the Develop Continuity of Operations Plan action (ma-AH-NVTA-001) and the Climate-Ready Transit Infrastructure Assessment action (ma-CCNVTA-001). Additional integration opportunities will occur through implementation of related capital, operational, and communication-focused mitigation actions, including Drainage Improvements for Bus Stops & Operations Center (ma-FL-NVTA-001), Bus Stop Shelter Expansion (ma-SW-NVTA-001), Enhance CAL OES SUBMITTAL - JUNE 2026
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Backup Power & Communication Systems (ma-WF-NVTA-002), Improve Bus Alert Systems (ma-AH-NVTA002), and Enhance Vehicle Air Quality & Cooling Systems (ma-WF-NVTA-001).
Administrative & Technical
NVTA’s administrative and technical capacity reflects its role as a transportation planning agency, funding administrator, and transit operator. Although NVTA is not a traditional emergency management organization and does not have a dedicated Emergency Manager, emergency coordination is supported through executive leadership, operations staff, and partnerships with Napa County OES and local jurisdictions. During hazard events, NVTA can support transit operations, evacuation mobility, service updates, and interagency coordination.
NVTA maintains important technical capabilities through in-house engineering, planning, communications, outreach, GIS, grant administration, and program management functions. Engineering staff support infrastructure planning, facility improvements, capital investments, and resilience-oriented project development. Communications and outreach staff provide public information, media coordination, emergency messaging, and bilingual engagement for Spanish-speaking communities. GIS support is available through planning staff, consultants, and partner agencies, though not through a dedicated GIS position. NVTA also has strong grant and program management capacity, which supports its ability to secure and administer funding for infrastructure, fleet modernization, and hazard mitigation-related investments.
Warning Systems & Services
NVTA’s warning and notification capabilities are focused on transit operations, service continuity, and rider communication rather than hazard detection or emergency alert issuance. Regional life safety alerts for wildfires, floods, earthquakes, and other major hazards are issued by Napa County emergency management agencies, while NVTA supports those efforts by providing transit-specific updates.
NVTA communicates service disruptions, detours, schedule changes, and safety-related information through tools such as the Transit App, agency websites, text messages, and social media. These platforms allow the agency to provide near real-time rider alerts during localized hazards, particularly flooding events that affect roads, routes, and service reliability. During wildfire or earthquake events, NVTA does not issue evacuation orders or hazard warnings, but it supports response efforts by coordinating service changes, sharing rider information, reinforcing County-led messaging, and communicating the status of transit operations, facilities, and safety conditions.
Fiscal
NVTA’s fiscal capabilities are shaped by its role as a congestion management agency, transportation planning authority, and transit operator. The agency does not have independent taxing authority and relies on voter-approved transportation sales tax measures, state and federal funding, grants, and farebox revenues to support transportation improvements and resilience-related investments.
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Transportation sales tax revenues are administered through the NVTA - Tax Agency, which manages voterapproved funding programs such as Measure T and Measure U. These programs provide a stable, long-term funding source for roadway maintenance, multimodal improvements, corridor enhancements, and projects with resilience co-benefits, including improvements that support emergency operations and evacuation routes. The NVTA - Tax Agency is governed by a 12-member Board representing Napa County’s incorporated jurisdictions and the County Board of Supervisors.
NVTA does not use utility fees, stormwater fees, system development fees, or developer impact fees, and it does not issue general obligation bonds or special tax bonds independent of voter-approved measures.
However, Measure U includes bonding authority that can help accelerate larger capital projects. NVTA’s strongest fiscal capability is its capital programming and grant administration capacity, which allows the agency to coordinate state, federal, and local funding for infrastructure upgrades, fleet modernization, facility improvements, and operational enhancements. These investments support system reliability, continuity of operations, and long-term hazard resilience.
Education & Outreach
NVTA’s education and outreach capabilities are primarily focused on transit services, transportation planning, and public information rather than hazard-specific education. However, the agency has several existing communication tools that could be expanded to support hazard awareness and rider preparedness, especially for transportation-dependent populations.
NVTA uses its website, social media platforms, public contact channels, and monthly e-newsletter to share service updates, rider resources, agency news, and operational information. While these platforms are not currently centered on hazard education, they provide a strong foundation for sharing future messaging related to wildfire impacts, PSPS events, extreme heat, flooding, service disruptions, evacuation-related transportation updates, and rider safety. Social media is particularly useful for timely updates during hazard events, allowing NVTA to communicate transit-specific impacts and reinforce County emergency messaging.
NVTA does not currently host standalone public safety events or maintain a formal hazard education program, and hazard materials are not widely distributed at physical public-facing locations. However, the agency could strengthen its outreach role by adding hazard preparedness content to its website and newsletter, providing printed or digital materials at transit facilities, and partnering with Napa County OES, local jurisdictions, Fire Safe Councils, Resource Conservation Districts, and other agencies on preparedness and resilience outreach.
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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 11-22: NVTA Capabilities and Opportunities Assessment HMP Integration
Resource Status
Current
Mitigation
Use
Future
Opportunity Notes / Additional Detail
Planning and Regulatory
Capabilities
Hazard Reduction Programs
(Annually Conducted)
Capital Improvements Program
(CIP) or Plan
Green Green Green
Current projects support planning, resilience,
and emergency operations. Coordination with
local/state/federal agencies to enhance
disaster response.
Annual Fire Prevention Plan
Orange Orange Yellow
NVTA does not manage facilities that require
their own fire prevention plans. Coordination
with local fire agencies possible.
Seismic Safety Program (Nonstructural) Yellow Yellow Yellow Seismic retrofits discussed in budget
narrative. Some projects potentially funded via
FEMA HMA.
Earthquake Modernization Plan
(Building Safety) Green Green Yellow Facility upgrades and seismic improvements likely embedded in capital planning.
Stormwater Management
Program (Annual Inspections) N/A N/A N/A NVTA is not responsible for stormwater management.
Hazard Plans and Programs
Floodplain Response Plan
Orange Orange Yellow
NVTA does not have operational flood
response duties; this lies with local
jurisdictions. No plan in place for its own
operations.
Community Wildfire Protection
Plan (CWPP) Orange Orange Yellow
Not a wildfire response agency. Some project
areas may intersect WUI; future coordination
possible.
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HMP Integration
Resource Status
Current
Mitigation
Use
Future
Opportunity Notes / Additional Detail
Ground Water Management
Planning / Plans N/A N/A N/A NVTA does not oversee groundwater. No planning responsibilities in this area.
Climate Action Plan
Green Green Green
NVTA has embedded sustainability and
climate adaptation goals in planning
documents. Prioritizes low-emission and zeroemission transit systems.
Drought Mgmt/ Contingency
Plan N/A N/A N/A Not applicable to NVTA’s mission or
operations.
FireWise Communities within
District N/A N/A N/A Not applicable to NVTA’s mission or operations.
Hazard-Related Public Outreach
Program Orange Orange Yellow No formal program; limited future opportunity within NVTA’s purpose and scope
Administrative and
Technical
Staff Capacity
Emergency Manager
Orange Orange Yellow No dedicated EM role; coordination likely via Executive/Deputy Director with County OES.
Civil Engineer Green Green Green Grant Bailey
Dedicated Public Outreach
Personnel
Green Green Green
Emily Charrier-Botts, who serves as
Communications & Outreach Coordinator,
managing the agency’s media platforms,
public events, emergency messaging, and
branded outreach initiatives. The Bilingual
Outreach Coordinator is currently (as of
September 2025) an open position. When filled,
the position, focuses on bilingual (Spanish)
community engagement efforts
GIS Specialist and Capability
Yellow Yellow Yellow
GIS capabilities likely through planning staff or
partnerships; no standalone GIS specialist. A
couple of NVTA staff members work with GIS.
Grant Manager, Writer, or
Specialist
Yellow Green Green
No dedicated staff member to perform grant
writing. Depending on the type of grant,
planning staff, finance staff or transit staff
write grant applications.
Other N/A N/A N/A
Warning Systems/Services
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HMP Integration
Resource Status
Current
Mitigation
Use
Future
Opportunity Notes / Additional Detail
General
Green Green Green
NVTA provides alerts via its website,
www.vinetransit.com, the Transit App,
through other third party platforms that ingest
General Transit Feed Specification (GTFS), text
messages and social media, but relies on Napa
County’s emergency alert systems for
regionwide hazards
Flood
Green Green Green
NVTA coordinates route changes and
notifications for riders during flood events.
Route alerts are published in real time via
mobile apps, text messages, its website, and
social media.
Wildfire
Yellow Yellow Yellow
NVTA does not issue wildfire alerts directly but
supports County-led alerts through
operational coordination and transit service
changes.
Geological Hazards
Green Green Green
Earthquake-related safety is addressed in
NVTA’s continuity and seismic retrofit
planning. Coordination with local EOC and
real-time updates during seismic events.
Fiscal Capabilities
Financial Resources for
Hazard Mitigation
Levy for Specific Purposes with
Voter Approval Green Green Yellow Has taxing authority (Measure U is our current ½ cent sales tax
Utilities Fees N/A N/A N/A Not a utility provider
System Development Fee
Orange Orange Yellow Not within authority; potential future opportunity with municipal partnerships
General Obligation Bonds to
Incur Debt Orange Orange Yellow
NVTA issues regional bonds via Measure U but
lacks powers for GO bonds; financing limited
to capital projects.
Special Tax Bonds to Incur Debt
N/A N/A N/A Does not have authority to issue special tax bonds.
Withheld Spending in HazardProne Areas Orange Orange Yellow No policy to withhold or reallocate spending based on hazard risk exists.
Stormwater Service Fees N/A N/A N/A Not a stormwater service provider Capital Improvement Project
Funding Green Green Green 24-25 Budget
Education / Outreach
Capabilities
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HMP Integration
Resource Status
Current
Mitigation
Use
Future
Opportunity Notes / Additional Detail
Education/Outreach
Resources
Website Dedicated to Hazard
Topics
Green Yellow Green
NVTA’s main site includes general emergency
info, but not specifically about hazards. Could
expand to include wildfire, PSPS, and climate
readiness.
Dedicated Social Media
Green Yellow Green
NVTA is active on platforms like Facebook,
instagram, and X, which can be leveraged for
hazard alerts and rider outreach
Hazard Info. Avail. at Library/
Planning Desk Orange Orange Yellow
No direct indication of hazard info at physical
sites; could be implemented at the transit
office or county library kiosks.
Annual Public Safety Events
Orange Orange Green
NVTA does not currently host public safety
events but could collaborate with County OES
or city events to promote transit safety during
hazards.
Ability to Field Public Tech.
Assistance Requests Yellow Yellow Green
NVTA accepts public input through
email/contact forms. Tech assistance specific
to hazard planning is not yet formalized.
Public Safety Newsletters or
Printed Outreach Orange Orange Green No newsletter currently; future opportunity Fire Safe Councils
Orange Orange Yellow
NVTA is not a member of Fire Safe Councils,
but could collaborate with local FSCs for
evacuation planning or fuel break
coordination.
Resource Conservation Districts
Orange Orange Green
No direct collaboration noted with Napa RCD.
Possible future partner for wildfire resilience
and slope stabilization near transit routes.
Other N/A N/A N/A
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11.6.2 Napa Valley Transportation Authority Mitigation Action Plan NVTA’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 NVTA 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 NVTA’s most significant hazards, including wildfire, earthquake, flood, drought, 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 NVTA is documented in Table 11-23, 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 11-10) that links the strategy to its associated hazard and supports consistent monitoring and reporting.
NVTA’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 district’s boundaries and require collaboration with county, regional, and state partners. By aligning local actions with regional strategies, NVTA helps to consolidate resources, maximize funding opportunities, and ensure that Figure 11-10: Mitigation Action Number Key
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mitigation projects achieve the greatest benefit for San Pablo Bay, 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 NVTA.
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Table 11-23: NVTA 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-NVTA002All Hazard SP , PRV 2026 Napa Valley
Transportation
Authority
Enhance
Backup Power &
Communication
Systems
Assess feasibility of installing a microgrid,
battery storage, or additional backup power,
and redundant communication systems at key
NVTA facilities to ensure service continuity
during extended outages, including systems
that can support electric bus charging. Pursue
funding, design, and installation for selected
solution(s).
Administration High High 5-10
Years
Project HMGP / BRIC ,
General Fund
Medium ps-WF-NVTA-003, ps-EHNVTA-003, ps-EQ-NVTA-334,
ps-AH-NVTA-333, ps-EQNVTA-001, ps-EQ-NVTA-334,
ps-FL-NVTA-001, ps-FLNVTA-002, ps-EH-NVTA-001,
ps-SF-NVTA-001, ps-SFNVTA-002, ps-WF-NVTA-001,
ps-WF-NVTA-002
ma-AH-NVTA001All Hazard PRV 2026 Napa Valley
Transportation
Authority
Develop
Continuity of
Operations Plan
Work with the TSA to create and adopt a
Continuity of Operations Plan (COOP) specific
to NVTA?s transit operations in the event of
major natural disaster(s) that can hamper the
agency?s ability operate normal service.
Administration Low Medium 1-3 Years Capacity /
Capability
Building
HMGP / BRIC ,
General Fund
High ps-AH-NVTA-002, ps-CCNVTA-001, ps-EQ-NVTA-001,
ps-EQ-NVTA-334, ps-SFNVTA-001, ps-SF-NVTA-002,
ps-WF-NVTA-001
ma-AH-NVTA002All Hazard ES , PE&A 2026 Napa Valley
Transportation
Authority
Improve Bus
Alert Systems
Develop and deploy an integrated emergency
communication system that includes digital
signage to help deliver timely hazard
notifications to riders.
Administration Medium Low 3-5 Years Project HMGP / BRIC , General Fund
Low ps-WF-NVTA-003, ps-EHNVTA-003, ps-EQ-NVTA-334,
ps-AH-NVTA-333, ps-EQNVTA-001, ps-EQ-NVTA-334,
ps-FL-NVTA-001, ps-FLNVTA-002, ps-EH-NVTA-001,
ps-SF-NVTA-001, ps-SFNVTA-002, ps-WF-NVTA-001,
ps-WF-NVTA-002
ma-CC-NVTA001Climate
Change
PRV 2026 Napa Valley
Transportation
Authority
Climate-Ready
Transit
Infrastructure
Assessment
Conduct a system-wide audit to assess and
prioritize upgrades for infrastructure
vulnerable to climate stressors (heat, flooding,
wildfire). Integrate findings into capital
improvement planning.
Administration Low Medium 1-3 Years Project HMGP / BRIC , General Fund ,
SMART
Medium ps-WF-NVTA-001, ps-SFNVTA-001, ps-EH-NVTA-001,
ps-FL-NVTA-002, ps-CCNVTA-001
ma-EH-NVTA001Extreme
Heat
SP 2026 Napa Valley
Transportation
Authority
Bus Stop
Shelter
Expansion
In collaboration with the right-of-way and
property owners, identify locations for bus
stop shelters or other passive cooling
measures to mitigate rider heat exposure.
Install shelters or other measures at the most
vulnerable and equitable stops.
Administration High High 3-5 Years Project HMGP / BRIC , General Fund ,
SMART
Medium ps-EH-NVTA-002, ps-EHNVTA-001, ps-CC-NVTA-001
ma-FL-NVTA001Flood SP 2026 Napa Valley
Transportation
Authority
Drainage
Improvements
for Bus Stops &
Operations
Center
In collaboration with the right-of-way and
property owners, assess bus routes and stops
for drainage and flooding issues. Implement
mitigation measures at vulnerable, highvolume bus stops and evaluate retrofits and drainage improvements for NVTA Operations
Center to ensure resilience against flooding.
Administration High High 3-5 Years Project HMGP / BRIC , General Fund ,
SMART
High ps-SF-NVTA-001, ps-SFNVTA-002, ps-CC-NVTA-001,
ps-FL-NVTA-001, ps-FLNVTA-002
ma-WF-NVTA001Wildfire SP , PRV 2026 Napa Valley
Transportation
Authority
Enhance
Vehicle Air
Quality &
Cooling
Systems
Upgrade bus ventilation, filtration, and cooling
systems to better protect drivers and
passengers from extreme heat and smoke
impacts during wildfire events.
Administration Medium Medium 3-5 Years Project HMGP / BRIC , General Fund ,
SMART
Medium ps-WF-NVTA-002, ps-WFNVTA-001, ps-EH-NVTA-001,
ps-CC-NVTA-001
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Section 12. Napa Sanitation District
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Napa County
2026 Multi-Jurisdictional Hazard Mitigation Plan Update Napa Sanitation District (NSD)
Special District Annex
Section 12. Napa Sanitation District........................................................................................ 12-7
12.1 Scope & Purpose ................................................................................................................................................................... 12-7
12.2 Jurisdictional Setting......................................................................................................................................................... 12-7
12.2.1 Geography & Climate ................................................................................................................................................ 12-8
12.2.2 Demographics & Vulnerable Populations........................................................................................................ 12-11
12.2.3 Economy......................................................................................................................................................................12-23
12.2.4 Growth Trends & Future Development............................................................................................................12-23
12.3 Planning Process ...............................................................................................................................................................12-24
12.3.1 Public Input & Draft Review .................................................................................................................................12-26
12.4 What’s New...........................................................................................................................................................................12-27
12.4.1 Mitigation Activities ...............................................................................................................................................12-27
12.4.2 Mitigation Successes..............................................................................................................................................12-28
12.5 Risk Assessment................................................................................................................................................................12-30
12.5.1 Hazard Screening & Prioritization .....................................................................................................................12-31
12.5.2 Vulnerability to Specific Hazards......................................................................................................................12-35
12.5.3 Climate Change Impacts & Vulnerable Populations..................................................................................12-52
12.5.4 Hazard Problem Statements................................................................................................................................12-52
12.6 Mitigation Strategy ........................................................................................................................................................... 12-55
12.6.1 Capabilities & Opportunities................................................................................................................................12-56
12.6.2 Napa Sanitation District Mitigation Action Plan ........................................................................................12-66 CAL OES SUBMITTAL - JUNE 2026
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List of Figures
Figure 12-1: NapaSan Geographic Overview Map.............................................................................................................. 12-10 Figure 12-2: NapaSan Median Household Income Map.................................................................................................. 12-12 Figure 12-3: NapaSan Poverty Status Map............................................................................................................................ 12-13 Figure 12-4: NapaSan Housing Occupancy Map................................................................................................................ 12-14 Figure 12-5: NapaSan Dependent Age Groups Map .......................................................................................................... 12-16 Figure 12-6: NapaSan Disabled Elderly Map........................................................................................................................ 12-17 Figure 12-7: NapaSan Race and Ethnicity Map .................................................................................................................. 12-19 Figure 12-8: NapaSan Spanish-Speaking Households Map...........................................................................................12-20 Figure 12-9: NapaSan CDC Social Vulnerability Index Map ..........................................................................................12-22 Figure 12-10: NapaSan Linear Generator Install.................................................................................................................12-29 Figure 12-11: Collection System Rehabilitation Project...................................................................................................12-30 Figure 12-12: NapaSan Risk Assessment Matrix................................................................................................................12-33 Figure 12-13: Exposure Summary – NapaSan Wildfire Risk .........................................................................................12-37 Figure 12-14: Exposure Summary – NapaSan Earthquake Risk (M7.1 Hunting Creek–Berryessa).............. 12-40 Figure 12-15: Exposure Summary – NapaSan Earthquake Risk (M6.7 West Napa).............................................. 12-41 Figure 12-16: Exposure Summary – NapaSan Liquefaction Risk................................................................................12-42 Figure 12-17: NapaSan Flood Risk (FEMA and DWR Awareness Zones) ................................................................. 12-44 Figure 12-18: Exposure Summary – NapaSan Flood Risk (FEMA Zones).................................................................12-45 Figure 12-19: Drought Severity Timeline 2000-2026.........................................................................................................12-48 Figure 12-20: Exposure Summary – NapaSan Sea Level Rise...................................................................................... 12-51 Figure 12-21: Mitigation Action Number Key.......................................................................................................................12-66 List of Tables
Table 12-1: NapaSan Planning Team and Steering Group Members..........................................................................12-25 Table 12-2: NapaSan Planning Team Meetings..................................................................................................................12-26 Table 12-3: NapaSan Document Review of Potential Hazards .....................................................................................12-32 Table 12-4: NapaSan Hazards Prioritization Summary...................................................................................................12-34 Table 12-5: Drought Classifications and Impacts...............................................................................................................12-47 Table 12-6: NapaSan Hazard Problem Statements............................................................................................................12-53 Table 12-7: NapaSan Capabilities and Opportunities Assessment.............................................................................12-62 Table 12-8: NapaSan Mitigation Action Plan.......................................................................................................................12-68 CAL OES SUBMITTAL - JUNE 2026
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Adoption Resolution
To comply with the Federal Disaster Mitigation Act of 2000 (DMA 2000), the Napa Sanitation District Board of Directors 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 district’s commitment to reducing the impacts of natural hazards within its jurisdiction and across Napa County.
A copy of the district’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 12. Napa Sanitation District
12.1 Scope & Purpose
This Jurisdictional Annex for the Napa Sanitation
District (NapaSan) of the 2026 Napa County MultiJurisdictional Hazard Mitigation Plan (MJHMP) details the hazard mitigation planning elements specific to the district’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 district. This annex provides additional information specific to the district, with a focus on hazard identification and risk assessment, vulnerability assessment, problem statements, mitigation strategy, and capabilities assessment. Below are NapaSan’s Points of Contact:
Primary Point of Contact Alternate Point of Contact
Matthew Lemmon, Engineering Director / District
Engineer
Napa Sanitation District
1515 Soscol Ferry Road
Napa, CA 94558
Telephone: (707) 258-6000
email: [email protected]
Amy Walcker, Human Resources Manager
Napa Sanitation District
1515 Soscol Ferry Road
Napa, CA 94558
Telephone: (707) 258-6000
email: [email protected]
12.2 Jurisdictional Setting
NapaSan is an independent special district that provides wastewater collection, treatment, recycled water supply, and biosolids management services within southern Napa County. NapaSan’s service area encompasses approximately 21 square miles, primarily serving the City of Napa, the Silverado Country Club area, the Napa County Airport, and several adjacent unincorporated areas of Napa County. NapaSan treats an average of approximately 10 million gallons per day (MGD) of wastewater, with facilities designed to accommodate both dry-weather and peak wet-weather flows.
NapaSan is governed by a Board of Directors and operates as a regional wastewater utility responsible for protecting public health, water quality, and environmental resources. As a publicly owned treatment works (POTW), NapaSan plays a critical role in regional infrastructure resilience, regulatory compliance, and emergency response coordination related to wastewater services. NapaSan’s mission emphasizes reliable service delivery, environmental stewardship, and regulatory compliance while proactively managing operational and climate-related risks.
NapaSan’s service area is located within the lower Napa River watershed and includes areas adjacent to the Napa River, Soscol Creek, and associated floodplains. Portions of the District’s facilities and conveyance CAL OES SUBMITTAL - JUNE 2026
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infrastructure are situated at relatively low elevations near tidal influences, making them susceptible to flooding, sea level rise, groundwater rise, and access constraints during extreme weather events. The district’s oxidation ponds and biosolids application sites occupy large tracts of land in areas influenced by hydrology, soil conditions, and seasonal groundwater variability.
NapaSan’s primary operational facilities are centered at the Soscol Water Recycling Facility, located at 1515 Soscol Ferry Road, just south of State Route 29. This complex includes the wastewater treatment plant (WWTP), administration buildings, oxidation ponds, electrical systems, and support infrastructure. The WWTP provides secondary and tertiary treatment, with a permitted average dry-weather discharge capacity of 15.4 MGD and peak wet-weather treatment capacity of approximately 23 MGD. Treated effluent is either discharged to the Napa River during the winter season or reused as recycled water during the dry season, consistent with Title 22 recycled water standards.
In addition to the treatment complex, NapaSan owns and operates an extensive network of collection system pipelines, recycled water distribution pipelines, multiple remote pump stations, recycled water booster pump and truck fill stations, and biosolids application sites distributed throughout the service area.
These assets span urban, agricultural, and low-lying riverine environments, resulting in varying exposure to flood, wildfire, seismic, and climate-related hazards.
NapaSan’s location within Napa County and the State of California are shown in Figure 12-1. ▪ Year of Incorporation: November 1945
▪ Number of connections: ~33,000
▪ Service area: ~21–23 square miles
▪ Average wastewater treated: ~10 MGD
12.2.1 Geography & Climate
NapaSan’s service area is located in southern Napa County, primarily within and adjacent to the City of Napa, and encompasses approximately 23 square miles. The district lies within the lower Napa River watershed, with key facilities situated near the confluence of Soscol Creek and the Napa River. The district’s primary operational facilities, including the Soscol Water Recycling Facility, oxidation ponds, and administrative headquarters, are located in relatively low-lying terrain south of downtown Napa, near tidal reaches of the Napa River. Figure 12-1 provides a regional location map showing NapaSan’s jurisdictional boundaries for sanitation services (recycled water boundary not shown).
NapaSan’s geographic footprint includes a mix of urbanized areas, agricultural lands, and open space, with infrastructure extending across floodplains, valley floors, and gently sloping terrain. Portions of the collection system, pump stations, and recycled water infrastructure are located near riverine and tidal environments, while biosolids application sites are generally situated in rural agricultural areas.
The Napa River is a dominant geographic feature influencing NapaSan’s operations. River stages in the lower watershed are affected by both upstream watershed runoff and tidal influences from San Pablo Bay, resulting in fluctuating water surface elevations. Tidal variation near NapaSan facilities can exceed 4 feet CAL OES SUBMITTAL - JUNE 2026
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between low and high tide, which, when combined with storm events, increases the potential for localized flooding and access challenges.
NapaSan is located in a Mediterranean climate zone, characterized by cool, wet winters and warm, dry summers. Most of the annual precipitation occurs between November and April, which coincides with NapaSan’s winter river discharge operational period. Average daily wastewater flows increase significantly during wet weather due to stormwater inflow and infiltration (I&I), placing added stress on collection and treatment infrastructure. The City of Napa and surrounding lower Napa Valley typically receive approximately 24 to 28 inches of rainfall annually, with year-to-year variability driven by atmospheric river events and broader climate cycles. Most rainfall occurs during winter storm events, while summers are generally dry with little to no precipitation. This seasonal concentration of rainfall aligns with NapaSan’s winter river discharge operational period.
Summer months are typically dry, with minimal rainfall and elevated temperatures. Periods of high heat coincide with peak recycled water demand for agricultural irrigation, landscaping, and golf courses served by NapaSan’s recycled water system. These seasonal climate patterns create a strong operational dependency on both precipitation timing and temperature extremes.
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Figure 12-1: NapaSan Geographic Overview Map
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12.2.2 Demographics & Vulnerable Populations
NapaSan provides wastewater collection, treatment, and recycled water services primarily to the City of Napa and adjacent unincorporated areas of Napa County. The service area includes a predominantly urban population, with additional agricultural, industrial, commercial, and tourism-related land uses that contribute to daily and seasonal variations in service demand.
As a special district, NapaSan does not directly manage population or land use; however, reliable wastewater services are essential to public health and community resilience. Certain groups within the service area may be more vulnerable to disruptions caused by natural hazards, including low-income households, older adults and individuals with disabilities, residents of multi-family housing, and critical facilities such as schools, healthcare facilities, and care homes.
Service interruptions during flood, wildfire, heat, or seismic events may disproportionately affect these populations by increasing health risks and delaying recovery. NapaSan’s hazard mitigation, capital improvement, and climate adaptation efforts support community resilience by prioritizing continuity of operations and protecting essential wastewater infrastructure serving vulnerable populations.
Income & Housing
NapaSan service area includes communities with a wide range of household income and housing characteristics, largely reflecting patterns within the City of Napa and surrounding unincorporated areas.
ACS data indicate that median household income varies substantially across the service area, with higherincome households more prevalent in peripheral and hillside areas, and lower-income households concentrated in portions of central and southern Napa. See Figure 12-2 As shown in Figure 12-3, areas with higher poverty rates are primarily located in the central and southern portions of the service area, including neighborhoods near the Napa River and major transportation corridors. These areas may be more sensitive to service disruptions and recovery delays following hazard events due to limited financial resources.
Housing occupancy patterns in Figure 12-4 also vary across the NapaSan service area. Owner-occupied housing is more common in outlying residential areas, while lower rates of homeownership and higher renter occupancy are concentrated in central Napa. Higher renter concentrations may indicate increased vulnerability during disasters, as renters often have fewer resources, less control over building resilience measures, and greater displacement risk.
Overall, the income and housing patterns within NapaSan’s service area highlight the importance of maintaining reliable wastewater services during and after hazard events, particularly in neighborhoods with lower incomes, higher poverty rates, and greater renter occupancy, where public health and recovery challenges may be more pronounced.
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Figure 12-2: NapaSan Median Household Income Map
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Figure 12-3: NapaSan Poverty Status Map
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Figure 12-4: NapaSan Housing Occupancy Map
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Dependent & Disabled Populations
NapaSan’s service area and Figure 12-5, includes neighborhoods with higher concentrations of dependent age groups, including children and older adults, primarily within central and southern portions of the City of Napa. These areas generally correspond with more urbanized neighborhoods near the Napa River and major transportation corridors.
ACS data and Figure 12-6, also indicate elevated proportions of elderly residents (65+) with disabilities in parts of the southern service area and select central neighborhoods. Individuals in these populations may have increased reliance on uninterrupted sanitation services, limited mobility during evacuations, and greater sensitivity to public health impacts resulting from service disruptions.
While NapaSan does not directly provide social or emergency services, maintaining reliable wastewater collection and treatment during hazard events is critical to protecting dependent and disabled populations, particularly during flooding, extreme heat, wildfire smoke events, and seismic emergencies. NapaSan’s emphasis on infrastructure reliability and continuity of operations supports community resilience for residents with limited adaptive capacity.
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Figure 12-5: NapaSan Dependent Age Groups Map
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Figure 12-6: NapaSan Disabled Elderly Map
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Race, Ethnicity & Language
NapaSan’s service area encompasses a racially, ethnically, and linguistically diverse population, largely reflecting demographic patterns within the City of Napa and surrounding unincorporated areas. ACS data indicate that while some portions of the service area are predominantly non-Hispanic White, other neighborhoods, particularly in central and southern Napa, have higher concentrations of Hispanic or Latino residents, along with smaller but notable populations of Asian, Black or African American, and other racial and ethnic groups
Figure 12-7 shows ethnic diversity is most pronounced in the urban core and river-adjacent areas, which also tend to overlap with neighborhoods experiencing higher renter occupancy, lower median household incomes, and greater concentrations of dependent or vulnerable populations. These areas may face compounded challenges during hazard events due to economic constraints, housing density, and limited access to resources.
Language data further indicate that Spanish is commonly spoken at home in several parts of the NapaSan service area, with some census tracts showing more than one-third of residents age five and older speaking Spanish at home, Figure 12-8. Households with limited English proficiency may experience barriers to accessing emergency information, understanding public health advisories, or navigating recovery assistance following disasters.
While NapaSan does not provide direct emergency communications or social services, awareness of racial, ethnic, and language diversity within the service area supports more inclusive hazard mitigation planning.
Coordination with Napa County, the City of Napa, and community partners helps ensure that critical information related to wastewater service disruptions, public health protection, and recovery efforts can be effectively communicated to all residents, including linguistically isolated populations.
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Figure 12-7: NapaSan Race and Ethnicity Map
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Figure 12-8: NapaSan Spanish-Speaking Households Map
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Social Vulnerability Index (SVI)
The Centers for Disease Control and Prevention (CDC) Social Vulnerability Index (SVI) for NapaSan 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).
SVI mapping indicates that moderate to high social vulnerability is concentrated in central and southern portions of the service area, primarily within the urban core of the City of Napa and along the Napa River corridor, Figure 12-9. These areas generally correspond with neighborhoods that have higher renter occupancy, lower median household incomes, greater proportions of dependent age groups, higher rates of disability among older adults, and increased linguistic isolation.
Areas with lower social vulnerability are more common in outlying residential and less densely developed portions of the service area. These neighborhoods tend to have higher household incomes, greater homeownership rates, and fewer socioeconomic barriers that can complicate disaster preparedness and recovery.
While NapaSan does not provide direct emergency response or social services, SVI patterns are relevant to hazard mitigation planning because wastewater service disruptions can disproportionately affect socially vulnerable populations. Maintaining reliable wastewater collection, treatment, and recycled water operations during hazard events is critical to protecting public health in higher-SVI areas, where residents may have fewer resources to cope with service interruptions or prolonged recovery periods. Awareness of SVI conditions supports coordination with Napa County, the City of Napa, and community partners to ensure mitigation investments and continuity-of-operations planning account for populations with reduced adaptive capacity.
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Figure 12-9: NapaSan CDC Social Vulnerability Index Map CAL OES SUBMITTAL - JUNE 2026
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12.2.3 Economy
NapaSan serves a service area with a diverse and regionally significant economy, centered primarily within the City of Napa and adjacent unincorporated areas of southern Napa County. The local economy is shaped by a combination of tourism, agriculture, hospitality, healthcare, manufacturing, and professional services, all of which depend on reliable wastewater collection, treatment, and recycled water services to function safely and sustainably.
The tourism and hospitality sector is a dominant economic driver within NapaSan’s service area. Hotels, restaurants, tasting rooms, and visitor-serving businesses generate significant employment and economic activity, particularly in central Napa and along major transportation corridors. These uses are highly dependent on continuous wastewater service and are sensitive to service disruptions during flood, wildfire, heat, or seismic events.
Agriculture and wine production also play a critical role in the regional economy. While much vineyard land lies outside urban areas, many agricultural processing, storage, and support facilities are located within NapaSan’s service area and rely on sewer service and recycled water. NapaSan’s recycled water system supports agricultural irrigation and landscape uses, contributing to long-term water supply resilience and economic stability during drought conditions.
Additional economic activity includes healthcare services, light industrial and manufacturing uses, government and education, and retail and commercial services, particularly within the City of Napa. These sectors contribute to a stable employment base but vary in their vulnerability to hazard-related disruptions.
ACS and ESRI demographic data indicate that parts of NapaSan’s service area include lower-income households, higher renter occupancy, and employment in service-oriented industries, particularly hospitality and agriculture. Workers in these sectors may experience greater economic vulnerability during disasters due to wage volatility, limited benefits, and reduced capacity to absorb prolonged disruptions.
Economic impacts from wastewater service interruptions may therefore disproportionately affect both workers and small businesses in higher social vulnerability areas.
NapaSan is a foundational component of the local economy, providing essential infrastructure that supports business continuity, public health, environmental compliance, and long-term economic growth. Disruptions to wastewater treatment or collection could have cascading economic impacts, including business closures, regulatory violations, loss of tourism revenue, and delayed recovery following hazard events.
12.2.4 Growth Trends & Future Development
NapaSan’s service area is largely built out, with future growth expected to occur primarily through infill development, redevelopment, and incremental intensification within the City of Napa, rather than largescale greenfield expansion. Growth patterns within the service area are shaped by local land use policies, environmental constraints, infrastructure capacity, and regional housing needs, all of which influence wastewater service demand.
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Future residential growth within the NapaSan service area is expected to be moderate and concentrated in existing urban areas, including downtown Napa, transit-accessible corridors, and designated infill opportunity sites. New housing development is anticipated to include a mix of multi-family housing, mixeduse projects, and accessory dwelling units (ADUs), reflecting state housing mandates and local planning priorities. These development patterns generally increase wastewater demand incrementally while placing greater emphasis on system reliability and peak wet-weather capacity rather than system expansion.
Economic development trends within the service area continue to emphasize tourism, hospitality, healthcare, and professional services, with limited expansion of heavy industrial uses. Redevelopment and reinvestment in existing commercial areas, particularly within central Napa, are expected to generate localized increases in wastewater flows and recycled water demand. Tourism-related growth may also contribute to seasonal fluctuations in wastewater generation, which must be accommodated during peak periods and hazard events.
Future development within the NapaSan service area is influenced by infrastructure capacity, floodplain considerations, water supply availability, and climate-related constraints. NapaSan’s long-range planning emphasizes optimizing existing facilities, reducing inflow and infiltration, and improving operational flexibility to accommodate growth without increasing hazard exposure. Climate change considerations, including increased storm intensity, sea level rise, and extreme heat, are expected to play a growing role in shaping where and how development occurs.
12.3 Planning Process
NapaSan 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 district’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 district, this included postings to the district website and social media, and outreach events, as documented in Appendix B. Examples of Key Stakeholders engaged by Napa County on behalf of the district with relevance to the development of NapaSan’s mitigation strategy include the USDA and other federal agencies; CAL FIRE and other state agencies; other jurisdictions; community-based organizations such as local Chamber of Commerce chapters; 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 district’s annex, as described in Volume 1 Table 2-9. The district’s internal planning team participants, their positions, and how they participated in the planning process are shown in Table 12-1.
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Table 12-1: NapaSan Planning Team and Steering Group Members Team Members Title Description of Involvement
Matthew Lemmon Engineering Director/District
Engineer Lead Point-of-Contact, HMPT #1, BO #1 and #2
Amy Walcker Human Resources Manager Alternate Point-of-Contact, HMPT #2, BO #1 and #2 Nick Hunter Safety, Training and Fleet
Maintenance Officer (STFMO)
Participating Stakeholder, HMPT #1, and #2, BO #1 and #2 NapaSan staff 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 12-2 that engaged the district’s planning team, which included key district 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 December 10, 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.
Throughout the series of breakout meetings, the district 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.
During the August 21, 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 9, 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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The meetings also included consensus-building activities around hazard rankings, capabilities, and planned actions, while providing regular updates on the overall project schedule.
Table 12-2: NapaSan 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
NapaSan Planning Team
Breakout Meeting #1
August 21, 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
NapaSan Planning Team
Breakout Meeting #2
June 9, 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
12.3.1 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. 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.
These comments were incorporated into the district’s mitigation strategy, as appropriate; although, most were already addressed by the Mitigation Action Plan which was based on previous public input.
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 CAL OES SUBMITTAL - JUNE 2026
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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.
12.4 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. This is the first time NapaSan has participated in the MJHMP process.
While not included in the 2020 plan, the district has since strengthened its focus on resilience through key efforts. Through this MJHMP process, NapaSan has identified its highest-priority hazards, developed hazard-specific problem statements, and proposed actionable mitigation strategies.
By aligning with countywide partners and leveraging regional resources, NapaSan has strengthened its capacity to prepare for, withstand, and recover from disasters while continuing to protect its unique coastal community character.
12.4.1 Mitigation Activities
Over the past decade, NapaSan has implemented a range of mitigation activities aimed at reducing vulnerability to flooding, seismic events, climate change impacts, and operational disruptions. These efforts have been integrated into capital improvement planning, asset management, recycled water expansion, and climate adaptation initiatives, supporting both infrastructure resilience and continuity of essential wastewater services.
NapaSan has made sustained investments in rehabilitating and replacing aging wastewater infrastructure, with a focus on reducing inflow and infiltration (I&I) and improving system performance during extreme rainfall events. Sewer main rehabilitation, condition-based replacement, and basin-specific upgrades have reduced the likelihood of system surcharging, sanitary sewer overflows, and treatment capacity exceedances during storms. These actions directly mitigate flood-related risks to public health and water quality.
At the wastewater treatment plant and associated facilities, NapaSan has upgraded critical mechanical, electrical, and control systems to improve operational reliability. Improvements include redundancy in key process components, modernization of treatment systems, and protection of sensitive equipment from flood exposure, supporting continued operations during hazard events.
Recognizing its location within the lower Napa River watershed and near tidal influences, NapaSan has taken steps to address flood and climate-related risks. These include evaluating vulnerabilities of oxidation ponds, levees, access roads, and low-lying facilities, as well as incorporating climate projections into longrange planning. NapaSan’s Climate Change Adaptation Plan identified priority risks related to sea level rise, extreme precipitation, groundwater rise, and heat, and established a framework for phased adaptation actions over time.
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Operational strategies, such as seasonal treatment and discharge adjustments, wet-weather flow management, and storage utilization, have also been refined to mitigate flood risk and maintain regulatory compliance during extreme events.
Expansion and optimization of NapaSan’s recycled water program over the last decade has provided mitigation benefits related to drought resilience and water supply reliability. By increasing the beneficial reuse of treated wastewater for agricultural irrigation, landscaping, and industrial uses, NapaSan has reduced dependence on potable water supplies during drought conditions and supported regional water resilience. Recycled water infrastructure improvements also reduce discharge volumes during the dry season, improving operational flexibility.
Implementation and ongoing refinement of an asset management program has allowed NapaSan to prioritize mitigation investments based on risk, condition, and criticality. By systematically identifying high-risk assets and failure consequences, NapaSan has improved decision-making related to capital improvements and hazard mitigation, ensuring limited resources are directed toward projects with the greatest risk-reduction benefits.
12.4.2 Mitigation Successes
Recycled Water Upgrade Project
NapaSan owns and operates the Soscol Water Recycling Facility (SWRF), which includes a wastewater treatment plant that produces recycled water, a recycled water pump station, and two recycled water storage reservoirs. To improve system reliability and redundancy, NapaSan is proposing upgrades to the Soscol Recycled Water Pump Station, including replacement of the existing jockey pump, installation of additional pumps and a new pump bay, and related electrical and control improvements. These upgrades will enhance operational efficiency, extend equipment life, and increase the reliability of recycled water delivery, providing additional drought resilience for NapaSan’s recycled water customers.
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Linear Generator
NapaSan has installed a new
linear generator at its
wastewater treatment plant
that is fueled by biogas
produced onsite through
anaerobic digestion. Developed
by Mainspring Energy, the
linear generator is a fuelflexible power generation
technology capable of
converting clean fuels,
including wastewater
treatment biogas, into reliable
electricity. The system is
expected to generate
approximately 230 kW of renewable electricity, making NapaSan the first wastewater treatment facility to operate a linear generator using digester-derived methane. This project supports NapaSan’s Climate Change Mitigation Plan by reducing greenhouse gas emissions, improving energy efficiency, and increasing operational resilience through onsite renewable power generation.
Sewer Line Rehabilitation
The Summer 2022 Collection System Rehabilitation Project focused on repairing and replacing aging sewer pipes within the project area to reduce the entry of stormwater and groundwater into the sewer system.
Napa Sanitation District crews conducted this work as part of the District’s ongoing collection system rehabilitation and maintenance program. The project addressed defects in sewer mains and laterals that contribute to inflow and infiltration and capacity constraints, followed by restoration of affected pavement and right-of-way areas. These improvements support NapaSan’s long-term strategy to enhance system performance, reduce the risk of failures during storm events, and protect public health and water quality.
Figure 12-10: NapaSan Linear Generator Install
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12.5 Risk Assessment
This section focuses on profiling hazards specific to NapaSan 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 district, and information on district-specific differences in hazard vulnerability across the planning area. It also identifies total district assets at risk, Figure 12-11: Collection System Rehabilitation Project
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including people, property, and critical facilities and infrastructure within the district. 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.
12.5.1 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.
NapaSan’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 district. Table 12-3 provides a crosswalk of hazards identified in select planning documents, including the 2020 Napa County MJHMP, 2019 NapaSan Strategic Plan, 2022 Climate Change Adaptation 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 NapaSan and which ones were not.
The internal planning group then ranked hazards based on their probability of affecting NapaSan and potential impacts on the community. Figure 12-12 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 district’s vulnerability to specifically identified hazards.
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Table 12-3: NapaSan Document Review of Potential Hazards Hazard 2020 Napa County
MJHMP
2022 NapaSan Climate
Change Adaptation 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 12-12: NapaSan 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 district’s Planning Team, before further refinement, are identified in the county’s completed matrix in Figure 12-12. Table 12-4 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 12-4: NapaSan Hazards Prioritization Summary
Hazard Priority Explanation
Earthquake / Liquefaction High Profiled in Volume 1, Section 3.3.4, and Section 12.5.2.2 in this annex, including Liquefaction
Wildfire Medium Profiled in Volume 1, Section 3.3.1, and Section 12.5.2.1 in this annex Flood High Profiled in Volume 1, Section 3.3.2, and Section 12.5.2.3 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 Medium
Profiled in Volume 1, Section 3.3.5, and Section 12.5.2.5 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 Medium Profiled in Volume 1, Section 3.3.6, and Section 12.5.2.4 in this annex Geologic / Mass Movement -
Profiled in Volume 1, Section 3.3.5; not a priority due to low probability and impact potential
Extreme Heat -
Profiled in Volume 1, Section 3.3.8; not a priority due to being outside jurisdictional mission and authority
Agricultural Pests -
Profiled in Volume 1, Section 3.3.9; not a priority due to being outside jurisdictional mission and authority
Sea Level Rise High Profiled in Volume 1, Section 3.3.9, and Section 12.5.2.6 in this annex under Climate Change
Climate Change High
Profiled in Volume 1, Section 3.3.9, and Section 12.5.2.6 in this annex, including Sea Level Rise and discussed as a compounding hazard in relevant profiles
Dam Failure -
Profiled in Volume 1, Section 3.3.3; not a priority due to low probability and impact potential
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12.5.2 Vulnerability to Specific Hazards
Assessing vulnerabilities exposes the unique characteristics of individual hazards and begins the process of narrowing down which areas within the district 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 district’s planning group estimated vulnerable populations, properties, and assets, and potential losses. In addition, the exposure of district assets to drought, earthquake, wildfire, flood, and climate change hazards were also considered.
Many of the hazard profiles include a snapshot map and damage estimation tables that illustrate the district’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 seven hazards for the Napa Sanitation District, some of which encompass subhazards such as Liquefaction and Heavy Rain.
Wildfire
SECTION 12.5.2.1
Earthquake
SECTION 12.5.2.2
Flood
SECTION 12.5.2.3
Drought
SECTION 12.5.2.4
Severe Weather
SECTION 12.5.2.5
Climate Change
SECTION 12.5.2.6
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Wildfire Hazard
Wildfire poses a primarily indirect but regionally significant hazard to the NapaSan due to the district’s proximity to wildland–urban interface areas and its reliance on continuous power, facility access, and staff availability during major wildfire events. While NapaSan’s core facilities are located within the urbanized area of the City of Napa, surrounding hillsides and open space areas are mapped as moderate to very high wildfire risk, creating the potential for cascading operational impacts even where direct facility exposure is limited.
The wildfire risk exposure map, Figure 12-13, shows that risk exposure within the NapaSan service area is relatively low. Mapping indicates that approximately 108 residents are located within wildfire hazard areas, representing a negligible portion of the district’s total service population. About 426 parcels, or roughly 1 percent of parcels within the service area, intersect wildfire hazard zones. The total assessed value of parcels within wildfire hazard areas includes approximately $437 million in improvement value (about 2 percent of total improvement value) and $245 million in content value (about 1 percent of total content value). No essential facilities, hazardous materials sites, or high-potential-loss facilities operated by NapaSan are located within mapped wildfire hazard areas. However, seven transportation and lifeline segments, representing approximately 2 percent of mapped lifeline infrastructure, intersect wildfire hazard zones, indicating potential vulnerability related to access and utility corridors.
Although direct wildfire exposure to NapaSan infrastructure is limited, wildfire events can still significantly affect district operations through indirect impacts. These include power outages and Public Safety Power Shutoffs, restricted access to facilities due to evacuation orders or road closures, reduced staff availability during regional emergencies, and degraded air quality that may affect worker safety and outdoor operations.
Wildfire impacts may also coincide with extreme heat events, increasing energy demand and compounding operational stress.
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Figure 12-13: Exposure Summary – NapaSan Wildfire Risk
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Earthquake Hazard
Earthquake hazard represents one of the most significant risks to NapaSan due to the district’s location within an active seismotectonic setting influenced by nearby faults, including the West Napa Fault and the Hunting Creek–Berryessa fault system. As shown in Figure 12-14, scenario modeling indicates that strong to very strong ground shaking would occur across nearly the entire NapaSan service area during a major earthquake. Under the Hunting Creek–Berryessa M7.1 scenario, approximately 72 percent of the population and 75 percent of parcels within the district are exposed to strong to severe shaking (Modified Mercalli Intensity VII–VIII). In this scenario, more than $12.9 billion in improved parcel value and approximately $10.2 billion in content value fall within areas of damaging ground motion, reflecting widespread potential for structural damage, service disruption, and economic loss. Critical lifeline infrastructure is particularly vulnerable, with roughly 60 percent of transportation and lifeline assets exposed to strong or very strong shaking, increasing the risk of system outages and delayed emergency response.
The West Napa M6.7 earthquake scenario shown in Figure 12-15, presents even greater exposure due to its proximity to the urban core and NapaSan facilities. Nearly the entire district, approximately 100 percent of the population and 99 percent of parcels, is projected to experience strong to severe shaking (MMI VII–VIII).
In this scenario, an estimated $20.1 billion in improved parcel value and $17.2 billion in content value are located within high‐intensity shaking zones, underscoring the potential for widespread damage to buildings, pipelines, pump stations, and treatment facilities. All transportation and lifeline infrastructure within the district is exposed under this scenario, highlighting the risk of extensive service interruptions, limited access for repairs, and cascading impacts to public health and safety. These earthquake scenarios emphasize the importance of NapaSan’s continued focus on seismic resilience, system redundancy, and emergency preparedness to maintain wastewater and recycled water services following a major seismic event.
Liquefaction
Liquefaction poses a significant secondary earthquake hazard for NapaSan due to the district’s location along the Napa River corridor and within areas characterized by young alluvial soils, shallow groundwater, and historic floodplain deposits (Figure 12-16). Much of NapaSan’s collection system, pump stations, and portions of its treatment and recycled water infrastructure are located in low-lying valley areas where liquefaction susceptibility is moderate to high. During strong ground shaking, these soil conditions can lose strength and stiffness, increasing the risk of ground settlement, lateral spreading toward the Napa River, and differential movement that can damage buried pipelines, manholes, and structural foundations. While liquefaction is a consideration in hazard mitigation planning, it is not profiled as a standalone hazard but addressed as a secondary earthquake effect.
In a major earthquake scenario, liquefaction-related ground failure could result in cracked or misaligned sewer mains, damaged force mains, and compromised pump station structures, leading to wastewater overflows, service interruptions, and extended repair timelines. Facilities located near waterways are particularly vulnerable to lateral spreading, which can exert significant forces on pipelines and appurtenant CAL OES SUBMITTAL - JUNE 2026
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structures. Even where surface structures remain intact, subsurface damage to gravity sewers and pressurized lines may be widespread and difficult to detect immediately, increasing the potential for postevent environmental impacts and public health concerns.
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Figure 12-14: Exposure Summary – NapaSan Earthquake Risk (M7.1 Hunting Creek–Berryessa) CAL OES SUBMITTAL - JUNE 2026
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Figure 12-15: Exposure Summary – NapaSan Earthquake Risk (M6.7 West Napa) CAL OES SUBMITTAL - JUNE 2026
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Figure 12-16: Exposure Summary – NapaSan Liquefaction Risk CAL OES SUBMITTAL - JUNE 2026
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Flood Hazard
Flooding represents a significant and well-documented hazard for NapaSan due to the district’s alignment with the Napa River and its extensive low-lying floodplain areas. FEMA flood hazard mapping indicates that substantial portions of NapaSan’s service area fall within the 100-year and 500-year flood zones, particularly along the Napa River corridor extending through the City of Napa and south toward San Pablo Bay. These flood-prone areas overlap with critical portions of the district’s wastewater collection system, pump stations, and treatment infrastructure, increasing exposure to inundation during major storm events and prolonged periods of high river flow.
Based on the exposure analysis and shown in Figure 12-18, approximately 11,600 residents, or about 15 percent of the population within the district, are located in FEMA-mapped flood hazard areas. More than 4,500 parcels, representing roughly 12 percent of total parcels, fall within the 100-year and 500-year floodplains. The potential economic exposure is substantial, with an estimated $1.66 billion in improved property value and approximately $1.31 billion in content value located within flood hazard areas. These figures underscore the potential for widespread property damage, service disruption, and costly recovery efforts following major flood events.
Flood risk is especially concentrated in areas adjacent to the Napa River, where floodways and leveeprotected zones coincide with critical infrastructure. While levees provide a degree of protection, residual risk remains from overtopping, structural failure, or events exceeding design capacity. Transportation and lifeline infrastructure is notably exposed, with approximately 40 percent of critical lifeline assets and 17 percent of total transportation and lifeline mileage located within flood hazard areas. Flooding of these assets can restrict access to facilities, disrupt wastewater conveyance, and complicate emergency response and recovery operations.
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Figure 12-17: NapaSan Flood Risk (FEMA and DWR Awareness Zones) CAL OES SUBMITTAL - JUNE 2026
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Figure 12-18: Exposure Summary – NapaSan Flood Risk (FEMA Zones) 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 12-5 depicts drought classifications and impacts from the level of drought occurrence in California, while Figure 12-19 shows a time series of the level of drought in Napa County from 2000 to 2026 according to the National Drought Monitor.
Drought is a persistent and escalating hazard for NapaSan due to the district’s reliance on regional water supplies, increasing climate variability, and growing demand for reliable wastewater and recycled water services. Napa County has experienced multiple prolonged droughts over the past decade, resulting in reduced surface water availability, stressed groundwater resources, and heightened competition among municipal, agricultural, and environmental water uses. While drought does not directly damage infrastructure in the same way as floods or earthquakes, it poses significant operational and financial risks to NapaSan by altering influent flows, reducing recycled water demand in some sectors, and increasing the importance of reliable alternative water supplies.
Extended drought conditions can reduce wastewater influent volumes as water conservation measures take effect, potentially affecting treatment efficiency and revenue stability. At the same time, drought increases the strategic importance of NapaSan’s recycled water system, which provides a locally controlled, drought-resilient supply for irrigation and non-potable uses. Facilities such as the Soscol Water Recycling Facility and associated pump stations and reservoirs play a critical role in offsetting potable water demand during dry periods. Ensuring the reliability and redundancy of this infrastructure is essential during drought conditions, when recycled water demand may increase even as overall wastewater flows decline.
Drought also creates indirect risks that intersect with other hazards. Reduced soil moisture and vegetation stress can contribute to land subsidence in localized areas, increase wildfire risk near facilities and conveyance corridors, and heighten the consequences of power outages during heat events. Operationally, drought-driven heat waves can place additional strain on mechanical and electrical systems, increase energy demands, and challenge workforce safety during outdoor maintenance activities.
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Table 12-5: 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 12-19: Drought Severity Timeline 2000-2026
Severe Weather Hazard
Although the City of Napa area benefits from a Mediterranean climate with some moderating marine influence from San Pablo Bay, the NapaSan remains vulnerable to a range of severe weather hazards, including high wind events and heavy rainfall. The most common problems associated with severe storms are loss of power, loss of access and, for a wastewater utility like NapaSan, inflow and infiltration (I&I) of stormwater into the collection system.
High Wind
High wind events can affect NapaSan by causing power outages or downing trees that block access for repairs or maintenance. Damage to overhead utilities and nearby electrical infrastructure can lead to power outages, potentially affecting critical collection and treatment systems, including communications and notification equipment.
Heavy Rain
Severe winter storm events can produce heavy rainfall, localized flooding, and hazardous site conditions.
These events are often associated with atmospheric river systems that bring prolonged and intense precipitation to the Napa Valley, increasing the potential for drainage system exceedance and localized inundation.
Heavy rainfall can result in saturated soils across NapaSan’s service area, particularly in lower-lying portions near the Napa River. These conditions may lead to ponding in intersections, blocked access roads, reduced effectiveness of stormwater infrastructure, and cause localized erosion or sediment transport.
However, such flooding or inflow and infiltration (I&I) of stormwater into the wastewater system can overwhelm NapaSan’s infrastructure and facilities, potentially causing sanitary sewer overflows. These releases can cause environmental pollution and public health emergencies.
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NapaSan has completed several I&I projects over the past decade. Projects have consisted of rehabilitating sewer mains, manholes, and laterals and have achieved varied success. With the driver for the program to reduce peak wet weather flows in lieu of implementing large conveyance projects. Combined with climate change-driven sea level rise and tidal influences, I&I will only worsen over time if additional wastewater infrastructure in vulnerable basins are not hardened to resist stormwater intrusion.
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 1901–1960 average to that of 1986–2016. Daily 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).
Climate change is a cross-cutting hazard for NapaSan that is expected to intensify the frequency, severity, and complexity of many existing natural hazards affecting the district’s infrastructure, operations, and service population. Regional climate projections for Napa County indicate increasing temperatures, more extreme precipitation variability, longer and more intense droughts, and a higher likelihood of extreme weather events. These changes have direct implications for wastewater treatment, recycled water production, energy use, and the long-term resilience of NapaSan’s facilities located along the Napa River and within low-lying valley areas.
Rising temperatures and more frequent heat waves can stress mechanical and electrical systems, increase energy demand for treatment processes, and pose occupational health risks for staff performing outdoor or confined-space work. Warmer conditions may also affect wastewater characteristics, including biological treatment performance and odor control, requiring adaptive operational strategies. At the same time, climate-driven drought conditions increase the strategic importance of NapaSan’s recycled water system as a reliable, locally controlled water supply, while also creating revenue and operational challenges associated with reduced influent flows during extended conservation periods.
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Climate change is also expected to amplify flood risk through more intense atmospheric river storms and altered runoff patterns. Even where flood control infrastructure and levees are in place, larger and more frequent storm events increase the likelihood of overtopping, infrastructure inundation, and access constraints during emergencies. These flood risks are compounded by sea level rise and higher tidal influences in downstream areas, which can reduce drainage efficiency and increase backwater effects along the Napa River corridor. For NapaSan, these conditions elevate the risk of service disruption, equipment damage, and environmental impacts if facilities are compromised during extreme events.
In addition, climate change contributes to increased wildfire risk and associated secondary impacts, including power outages, smoke exposure, and debris flows following burn scars. While much of NapaSan’s core infrastructure lies outside the highest wildfire hazard severity zones, utility shutoffs and regional emergency conditions can disrupt operations and staffing. Climate-driven seismic secondary hazards, such as liquefaction potential influenced by groundwater conditions, further underscore the interconnected nature of climate impacts on the district’s systems.
Sea Level Rise
Sea level rise presents a growing long-term hazard for NapaSan due to the district’s downstream location along the Napa River and its hydraulic connection to San Pablo Bay. While much of NapaSan’s service area lies inland, low-lying southern portions of the district, particularly areas adjacent to tidal reaches of the Napa River and wetlands, are vulnerable to rising sea levels, higher tidal elevations, and increased backwater effects. These conditions can reduce the effectiveness of gravity drainage, increase baseline water levels in the river system, and exacerbate flooding during storm events.
Exposure analysis as shown in Figure 12-20 indicates that current sea level rise scenarios result in relatively limited direct impacts within the district when compared to other hazards, but the risks are spatially concentrated and operationally important. Approximately 1,270 residents, or about 2 percent of the population, are located within areas exposed to projected sea level rise ranging from low to intermediatehigh scenarios. Fewer than 40 parcels fall within these exposure areas, with relatively low associated improvement and content values compared to flood or earthquake hazards. However, several transportation and lifeline segments—approximately 3 percent of system mileage—are located within areas influenced by sea level rise, highlighting potential access and operational challenges rather than widespread structural loss.
The primary concern for NapaSan is not immediate inundation of large service areas, but the compounding effects of sea level rise on flood risk, groundwater levels, and system performance over time. Rising sea levels can increase groundwater elevations and reduce hydraulic gradients, placing additional stress on buried sewer infrastructure, increasing the potential for infiltration and inflow, and reducing conveyance efficiency during wet-weather events. Sea level rise also heightens the risk of prolonged flooding in downstream areas during extreme tides combined with storm-driven river flows.
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Figure 12-20: Exposure Summary – NapaSan Sea Level Rise CAL OES SUBMITTAL - JUNE 2026
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12.5.3 Climate Change Impacts & Vulnerable Populations
Climate change disproportionately affects vulnerable populations within NapaSan’s service area by amplifying existing social, economic, and health inequities. Rising temperatures, more frequent heat waves, intensified flooding, prolonged droughts, and degraded air quality place greater strain on residents who have fewer resources to prepare for, respond to, and recover from hazard events. Communities located in low-lying areas near the Napa River, where flood risk and sea level rise impacts are concentrated, are more likely to experience repeated disruptions that affect housing stability, access to services, and public health.
Social Vulnerability Index patterns within the district indicate that higher vulnerability is clustered in parts of central and southern Napa, where higher proportions of low-income households, renters, elderly residents, and individuals with disabilities are present. These populations may face increased risks during climate-driven events due to limited mobility, reliance on electrically powered medical equipment, or reduced access to transportation during evacuations or service disruptions. Flooding and extreme heat can also disproportionately affect older adults and people with chronic health conditions, increasing the likelihood of heat-related illness, respiratory stress, and extended recovery times following disasters.
Language and cultural barriers further compound climate vulnerability for some residents within NapaSan’s service area. Areas with higher proportions of households that speak Spanish or other languages at home may face challenges accessing timely emergency information, preparedness guidance, and post-event assistance if outreach is not culturally and linguistically appropriate. During climate-related emergencies, such as floods or wildfire smoke events, delays or gaps in communication can increase exposure and limit the effectiveness of protective actions.
Climate change also intersects with housing vulnerability, particularly in neighborhoods with higher renter occupancy and older housing stock. These areas may experience greater impacts from flooding, heat stress, or utility disruptions, while residents often have limited ability to invest in property-level mitigation or recovery. For NapaSan, climate change impacts on vulnerable populations underscore the importance of maintaining reliable wastewater and recycled water services during extreme events, as service disruptions can quickly escalate public health risks in densely populated or socially vulnerable areas.
12.5.4 Hazard Problem Statements
As part of the mitigation action identification process, the Planning Committee 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 12-6. 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 12-8 for a full list of mitigation actions and CAL OES SUBMITTAL - JUNE 2026
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corresponding problem statements that they address. Each problem statement is coded with a problem number for cross-referencing between Table 12-6 and Table 12-8 Table 12-6: NapaSan Hazard Problem Statements
Problem No. Hazard Area of
Concern
Primary
Agency
Problem Description Related MA
ps-SR-NSD-001 Climate
Change
Threat Napa
Sanitation
District
Sea-level rise increases overtopping risk at
pond levees, accelerates structural
degradation, and compounds storm surge and
tidal flooding impacts along more than 9 miles
of wastewater and recycled water
infrastructure.
ma-SR-NSD-001
ps-SR-NSD-002 Climate
Change
Impact Napa
Sanitation
District
Rising groundwater tables and saltwater
intrusion from sea-level rise increase
infiltration, buoyancy hazards, pipeline
corrosion, and operational instability for
gravity mains, force mains, and recycled water
systems.
ma-SR-NSD-001,
ma-DR-NSD-001
ps-SR-NSD-003 Climate
Change
Victim Napa
Sanitation
District
Customers in low-lying and tidally influenced
areas face service interruptions or backups
from SLR-driven flooding during king tides
and storm conditions.
ma-SR-NSD-001
ps-CC-NSD-001 Climate
Change
Threat Napa
Sanitation
District
Climate change is causing sea-level rise,
changes in precipitation patterns, and more
extreme hazard events like wildfire and flood,
threatening reliability of the sanitary system.
ma-SR-NSD-001,
ma-DR-NSD-001,
ma-FL-NSD-001,
ma-WF-NSD-001,
ma-AH-NSD-001
ps-DR-NSD-001 Drought Impact Napa
Sanitation
District
Prolonged drought reduces influent flow and
recycled water availability, increasing
operational strain on treatment processes and
limiting summer recycled water distribution
capacity.
ma-DR-NSD-001
ps-DR-NSD002Drought Impact Napa
Sanitation
District
Drought-driven low wastewater flows increase
solids accumulation, odor generation,
corrosion risk, and collection system
maintenance needs.
ma-DR-NSD-001
ps-DR-NSD003Drought Impact Napa
Sanitation
District
Soil desiccation and subsidence during
extreme drought cause pipeline misalignment,
cracking, joint failures, and structural stress at
utility crossings.
ma-DR-NSD-001
ps-DR-NSD005Drought Victim Napa
Sanitation
District
Recycled water customers face delivery
cutbacks or quality variability during extreme
drought, affecting economic and operational
continuity.
ma-DR-NSD-001
ps-EQ-NSD-001 Earthquake Impact Napa
Sanitation
District
Strong ground shaking can disrupt treatment
and collection systems, damage pipelines, and
cause cascading failures in communication
systems, access roads, and power
infrastructure.
ma-EQ-NSD-001
ps-EQ-NSD002Earthquake Threat Napa
Sanitation
District
Aging or unreinforced assets lack modern
seismic hardening, increasing risk of rupture,
overflow, or structural collapse.
ma-EQ-NSD-001
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Problem No. Hazard Area of
Concern
Primary
Agency
Problem Description Related MA
ps-EQ-NSD003Earthquake Impact Napa
Sanitation
District
Damage to transportation routes may prevent
staff and contractors from accessing critical
assets, delaying emergency repairs and
restoration of operations.
ma-EQ-NSD-001
ps-EQ-NSD004Earthquake Impact Napa
Sanitation
District
Backup power systems may not provide
adequate redundancy during extended postearthquake outages, risking treatment compliance.
ma-EQ-NSD-001,
ma-AH-NSD-001
ps-FL-NSD-001 Flood Threat Napa
Sanitation
District
Riverine flooding and storm surge threaten
primary access routes to the WWTP,
restricting staff mobility and delaying
emergency repairs.
ma-FL-NSD-001
ps-FL-NSD-002 Flood Impact Napa
Sanitation
District
Flooding at West Napa, River Park, and
Stonecrest pump stations, combined with
increased I&I and creek erosion from heavy
rain events, causes equipment damage,
electrical failures, and overflow risk.
ma-FL-NSD-001,
ma-AH-NSD-001
ps-FL-NSD-003 Flood Impact Napa
Sanitation
District
Severe flood events can force system
shutdowns disrupting collection, treatment,
recycled water delivery, and revenue recovery.
ma-FL-NSD-001,
ma-AH-NSD-001
ps-FL-NSD-004 Flood Victim Napa
Sanitation
District
Operations staff face safety risks, limited
access, and hazardous working conditions
during flood events and emergency responses.
ma-FL-NSD-001
ps-FL-NSD-005 Flood Victim Napa
Sanitation
District
Low-lying neighborhoods and critical facilities
are vulnerable to sewer backups and service
disruptions during flood events. Downstream
populations, natural areas, and critical
facilities face impacts from uncontrolled
discharges or bypasses if floodwaters
compromise systems.
ma-FL-NSD-001
ps-FL-NSD-006 Flood Threat Napa
Sanitation
District
Aging collection system components and
undersized drainage structures worsen
localized flooding, erosion, and facility access
challenges.
ma-FL-NSD-001
ps-EW-NSD001Severe
Weather
Impact Napa
Sanitation
District
Heavy rain events that increase I&I or lead to
flooding can overwhelm wastewater
infrastructure, potentially causing sanitary
sewer overflows.
ma-FL-NSD-001
ps-EW-NSD002Severe
Weather
Impact Napa
Sanitation
District
High winds can fell trees and damage
electrical infrastructure, cutting off power to
critical facilities and blocking maintenance
and repair access, especially at remote pump
stations.
ma-AH-NSD-001
ps-SW-NSD001Severe
Weather
Threat Napa
Sanitation
District
Severe weather events like atmospheric rivers
are becoming more frequent due to climate
change, threatening treatment process
interruptions and pump station operability
from heavy rain and high wind events.
ma-FL-NSD-001,
ma-AH-NSD-001
ps-WF-NSD001Wildfire Threat Napa
Sanitation
District
Wildfire and PSPS events threaten power
supply reliability, expose critical facilities to
damage, and elevate structural failure risks
along pipeline corridors.
ma-AH-NSD-001,
ma-WF-NSD-001
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Problem No. Hazard Area of
Concern
Primary
Agency
Problem Description Related MA
ps-WF-NSD002Wildfire Victim Napa
Sanitation
District
Extended PSPS or wildfire-driven outages may
exceed on-site generator fuel capacity, risking
treatment process interruptions and pump
station operability.
ma-AH-NSD-001
ps-WF-NSD003Wildfire Victim Napa
Sanitation
District
Contractors and off-site personnel may be
unable to access critical assets due to road
closures or active fire conditions, delaying
service restoration.
ma-WF-NSD-001
12.6 Mitigation Strategy
This section provides the framework for how NapaSan 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 district’s prioritized mitigation actions. Together, these elements demonstrate how NapaSan 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 NapaSan, the strategy outlined in this annex reflects the outcomes of the countywide planning process while also addressing the district’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 district, county, and regional planning mechanisms. Each action identifies responsible parties, potential funding sources, and the resources needed for implementation.
For NapaSan, this strategy provides a framework for strengthening resilience by combining district-led initiatives, such as infrastructure improvements, and community preparedness, with regional coordination through the MJHMP. By advancing these efforts in alignment with the Strategic Plan and other local planning documents, NapaSan 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 12.6.1, Capabilities and Opportunities, provides a summary of NapaSan’s capacity to address natural hazards.
▪ Section 12.6.2, Mitigation Action Plan, presents the district’s prioritized actions to guide implementation in coordination with countywide strategies.
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Aligning the Action Plan
This section connects NapaSan’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 NapaSan’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.
12.6.1 Capabilities & Opportunities
This section provides a detailed assessment of NapaSan’s current capabilities to support hazard mitigation, as well as future opportunities. This consists of describing how the district is planning for hazards and growth and a summary of its existing capabilities and the potential for enhancement.
Planning for Hazards & Growth
Planning for hazards and growth is a central responsibility of NapaSan, given its role in providing essential wastewater and recycled water services to a growing and hazard-prone region. NapaSan operates within a dynamic planning environment shaped by seismic risk, flooding along the Napa River, climate change, and long-term development pressures in and around the City of Napa. To address these challenges, the district integrates hazard awareness, infrastructure resilience, and growth projections into its long-range planning, capital improvement programming, and operational decision-making.
As development occurs within NapaSan’s service area, the district plans for system capacity, redundancy, and adaptability to ensure new growth does not exacerbate existing vulnerabilities. This includes aligning sewer and recycled water system expansions with local land use plans, zoning, and regional growth forecasts, while also accounting for increased demand during peak wet-weather events and long-term climate variability. Growth planning places particular emphasis on protecting infrastructure located in flood-prone and liquefaction-susceptible areas, ensuring that new facilities and system upgrades are designed to withstand anticipated hazard conditions and future regulatory requirements.
Hazard planning is embedded in NapaSan’s capital improvement planning process, which prioritizes projects that reduce risk, enhance system reliability, and support rapid recovery following disasters.
Investments in pipeline rehabilitation, pump station upgrades, seismic strengthening, flood resilience, and energy reliability reflect a proactive approach to managing both current and future hazards. The district also coordinates closely with Napa County, the City of Napa, flood control agencies, and emergency management partners to align its planning efforts with regional hazard mitigation strategies and emergency response frameworks.
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Development & Hazard Considerations
Development and hazard considerations are closely intertwined for NapaSan due to the district’s service area encompassing both established urban neighborhoods and areas influenced by environmental constraints such as floodplains, seismic hazards, and climate-related risks. As land development and redevelopment occur within the City of Napa and surrounding areas, NapaSan must ensure that wastewater and recycled water infrastructure is planned, designed, and operated in a manner that minimizes exposure to natural hazards while accommodating future growth. This requires careful coordination with local land use policies, zoning regulations, and regional planning efforts.
Much of the district’s infrastructure is located in low-lying valley areas near the Napa River, where flood risk and liquefaction potential are elevated. New development in or near these areas increases the importance of designing conveyance systems, pump stations, and treatment facilities that can withstand inundation, ground movement, and prolonged service disruptions. NapaSan evaluates development proposals to ensure adequate system capacity, proper elevation of critical components, and compatibility with floodplain management requirements. Where growth occurs in hazard-prone areas, additional design standards and mitigation measures are necessary to reduce long-term risk and protect both new and existing infrastructure.
Seismic hazards also play a key role in development considerations, particularly given the proximity of active faults and the potential for strong ground shaking across the entire service area. As development intensifies, the consequences of infrastructure failure increase, reinforcing the need for seismic design standards, flexible pipeline materials, and redundancy within the system. NapaSan incorporates lessons learned from past earthquakes and scenario modeling into its planning to ensure that new facilities and system upgrades are resilient and capable of rapid post-event recovery.
Climate change adds another layer of complexity to development planning by altering hazard conditions over time. Increased precipitation intensity, longer droughts, and higher temperatures influence how infrastructure must be sized, protected, and operated. NapaSan considers these evolving conditions when planning for growth, emphasizing adaptable designs that can accommodate future uncertainty.
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 district’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.
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▪ 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 NapaSan 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 NapaSan summarizes the various types of capabilities it has for hazard mitigation currently. The assessment also identifies opportunities to integrate, expand, and improve the district’s capabilities for future hazard mitigation. Table 12-7 provides a comprehensive list of capabilities and identifies the current status, current mitigation use, and future opportunities.
Planning & Regulatory
NapaSan demonstrates strong planning and regulatory capabilities, with hazard mitigation primarily integrated into long-range planning, capital investment, and regulatory compliance efforts. The district’s 10-Year Capital Improvement Plan is a key strength, supporting infrastructure reliability, resource recovery, and system resilience through projects such as aging asset rehabilitation, inflow and infiltration reduction, pump station upgrades, and wastewater treatment plant improvements.
Although NapaSan does not maintain standalone plans for fire prevention, seismic safety, earthquake modernization, or floodplain response, these hazards are addressed through master planning, asset condition assessments, system capacity analysis, and capital programming. Seismic and building safety needs are incorporated into the Wastewater Treatment Plant Master Plan and Collection System Master Plan, while flood risk is addressed through capacity improvements, I&I reduction, stormwater coordination, and NPDES compliance.
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NapaSan also has strong capabilities related to climate action, drought management, groundwater planning, stormwater coordination, and public outreach. The 2023 Climate Change Mitigation Plan, regional drought planning, recycled water system planning, and conservation outreach all support long-term resilience.
Overall, NapaSan has a mature and integrated approach to hazard mitigation, with opportunities to strengthen its program through more formal hazard-specific planning and expanded coordination on wildfire and flood resilience.
Future integration of the MJHMP will occur through various processes and mechanisms outlined across multiple mitigation actions (Table 12-8). Key opportunities for future hazard mitigation integration with the districts existing planning mechanisms include using the updated risk assessment, hazard-specific vulnerability findings, and projected climate change impacts to inform implementation of the I&I Reduction & Flood Resilience Program (ma-FL-NSD-001), SLR Resilience Program (ma-SR-NSD-001), and Recycled Water Reliability & Drought Resilience Program (ma-DR-NSD-001).
Administrative & Technical
NapaSan’s administrative and technical capabilities reflect a lean organizational structure that relies on cross-trained staff and integrated management rather than dedicated hazard-specific positions. The district does not have a designated Emergency Manager; instead, emergency management responsibilities are assumed by the General Manager and operations and maintenance supervisors during incidents. While this structure allows for flexibility and direct operational oversight, it also presents an opportunity to further formalize emergency management roles and succession planning as hazards and regulatory expectations continue to increase.
Technical capacity is a notable strength for NapaSan, particularly in engineering and infrastructure delivery. The district maintains strong in-house civil engineering expertise through its Capital Program Manager and Senior Civil Engineer, supporting the planning, design, and implementation of capital projects that enhance system reliability and hazard resilience. This technical foundation enables NapaSan to proactively address aging infrastructure, seismic considerations, flood exposure, and climate-related risks through its capital improvement program and master planning efforts.
Administrative support functions such as public outreach, GIS, and grant management are handled by existing staff rather than dedicated specialists. Outreach activities are coordinated through Administrative Services and communications functions, while GIS capabilities are integrated into the district’s computerized maintenance management system and asset management processes. Similarly, grant identification and administration are managed by Finance staff as part of broader fiscal responsibilities.
While these approaches are effective for current operations, expanding capacity in these areas could enhance NapaSan’s ability to pursue external funding, improve hazard-related data analysis, and strengthen community engagement.
Overall, NapaSan’s administrative and technical capabilities support effective day-to-day operations and long-term infrastructure planning, but continued growth, increasing hazard complexity, and evolving regulatory requirements may warrant additional staffing or formalized roles. Enhancing emergency CAL OES SUBMITTAL - JUNE 2026
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management coordination, GIS capacity, and grant development resources would further strengthen the district’s ability to implement hazard mitigation projects and sustain resilient service delivery.
Warning Systems & Services
NapaSan benefits from a combination of regional warning systems and internal operational monitoring tools to support situational awareness during hazard events. For general emergencies, the district relies on Napa County’s public alert systems, including Nixle and County Alert, to receive timely notifications related to evacuations, severe weather, and other regional hazards. Internally, NapaSan uses its computerized maintenance management system and SCADA alarms to monitor system performance, detect operational anomalies, and respond quickly to equipment failures or abnormal conditions, providing a strong foundation for operational warning and response.
Flood warning capabilities are primarily based on monitoring and coordination rather than a dedicated District-specific alert system. NapaSan tracks river discharge, rainfall, and system performance and coordinates closely with the City of Napa and Napa County flood managers during storm events. While this approach allows the district to respond to changing conditions, it presents an opportunity to formalize floodspecific thresholds or protocols that link external river forecasts with internal operational triggers.
Wildfire and geological hazard warnings are similarly addressed through regional and state systems rather than standalone District programs. NapaSan relies on County and Cal Fire alerts for wildfire-related warnings and situational updates, including evacuation information and public safety power shutoff notifications. For earthquakes, the district does not maintain a dedicated seismic warning system but benefits from statewide and federal tools such as the USGS ShakeAlert system, which provides limited early warning prior to strong ground shaking.
Overall, NapaSan’s warning systems and services are effective in leveraging regional resources and internal monitoring capabilities, but they remain largely decentralized. Formalizing hazard-specific response protocols tied to existing warning systems—particularly for floods, wildfires, and seismic events—could further strengthen preparedness and improve the district’s ability to proactively protect critical infrastructure and maintain service continuity during emergencies.
Fiscal
NapaSan has strong fiscal capabilities to support hazard mitigation, primarily through utility-based revenue mechanisms and long-term capital planning rather than voter-approved taxes or special financing tools.
The district’s primary and most reliable source of funding for mitigation-related investments is its sewer service fees, which provide a stable revenue stream to support operations, maintenance, and capital improvements that reduce vulnerability to hazards. In addition, system development fees assessed on new development help ensure that growth contributes proportionately to infrastructure capacity and resilience.
NapaSan has historically relied on a pay-as-you-go financing approach and has made limited use of general obligation bonds or special tax bonds. While this conservative fiscal strategy supports financial stability and CAL OES SUBMITTAL - JUNE 2026
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minimizes long-term debt, it may also limit the district’s ability to rapidly scale large mitigation projects without phased implementation. Voter-approved levies for specific purposes are not currently used, representing a potential but unrealized funding option for future hazard mitigation needs.
Although NapaSan does not maintain an explicit policy to withhold spending in hazard-prone areas, hazard considerations are incorporated into capital improvement prioritization. The district’s 10-Year Capital Improvement Program serves as the central fiscal tool for hazard mitigation, integrating asset management, inflow and infiltration reduction, recycled water system improvements, and climate adaptation projects. By directing capital funding toward rehabilitation, system hardening, and reliability upgrades, particularly in areas of known flood, seismic, or climate risk, NapaSan effectively reduces long-term exposure while maintaining fiscal discipline.
Overall, NapaSan’s fiscal capabilities support a proactive, infrastructure-focused approach to hazard mitigation. Continued integration of hazard risk into capital planning, along with exploration of additional financing mechanisms or grant opportunities, could further enhance the district’s capacity to address emerging risks and implement large-scale resilience projects as conditions evolve.
Education & Outreach
NapaSan demonstrates strong education and outreach capabilities, particularly in areas related to drought awareness, water conservation, and customer engagement. The district maintains a public-facing website that provides information on water conservation practices and drought conditions, supporting community understanding of water resource challenges and the role of wastewater and recycled water systems in longterm resilience. NapaSan also actively uses social media, particularly Facebook, to share timely information and updates related to drought conditions, conservation messaging, and District activities.
NapaSan regularly participates in community events, including local fairs, water conservation days, and public outreach initiatives, which provide opportunities to engage directly with residents, businesses, and agricultural users. These events support education on water use efficiency, recycled water benefits, and the importance of maintaining reliable wastewater services. In addition, the district provides technical assistance to the public and customers on wastewater-related issues and conservation practices, helping address questions and concerns that may arise during droughts or other hazard conditions.
Printed outreach materials, including newsletters and billing inserts, are used to reinforce key messages and reach customers who may not access information online or through social media. This multi-channel approach enhances the district’s ability to communicate consistently across diverse audiences. While NapaSan does not maintain formal partnerships with Fire Safe Councils or the Napa County Resource Conservation District for hazard outreach, these organizations represent future opportunities for collaboration, particularly related to wildfire resilience and infrastructure protection. Overall, NapaSan’s education and outreach capabilities support public awareness and preparedness, with a strong foundation that can be expanded to address a broader range of hazard mitigation topics over time.
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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 12-7: NapaSan Capabilities and Opportunities Assessment HMP Integration
Resource Status
Current
Mitigation
Use
Future
Opportunity Notes / Additional Detail
Planning and Regulatory
Capabilities
Hazard Reduction Programs
(Annually Conducted)
Capital Improvements Program
(CIP) or Plan
Green Green Green
10-Year Capital Improvement Plan directly tied
to Strategic Plan Goals (Infrastructure
Reliability, Resource Recovery; updated
annually with focus on rehabilitation, inflow &
infiltration (I&I) reduction, pump station
upgrades, and plant reliability projects
Annual Fire Prevention Plan
Orange Orange Green
No standalone plan; addressed through OSHA
compliance, Cal/OSHA workplace
requirements, and facility-level fire protection
measures (chemical storage, digester safety);
future opportunity
Seismic Safety Program (Nonstructural)
Yellow Yellow Green
No standalone program; seismic evaluations
conducted through WWTP Master Plan and
asset condition assessments; retrofits
addressed through CIP and Master Plan
projects; future opportunity
Earthquake Modernization Plan
(Building Safety) Yellow Yellow Green
No formal plan; facilities assessed in WWTP
Master Plan and Collection System Master
Plan; future opportunity
Stormwater Management
Program (Annual Inspections)
Green Green Green
WWTP Master Plan and permit compliance
(NPDES) require stormwater monitoring and
management; inspections conducted annually
for treatment facilities and collection systems
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HMP Integration
Resource Status
Current
Mitigation
Use
Future
Opportunity Notes / Additional Detail
Hazard Plans and Programs
Floodplain Response Plan
Orange Orange Green
No standalone floodplain response plan;
considered in the Collection System Master
Plan (capacity, I&I) and WWTP Master Plan;
future opportunity to coordinate with
City/County
Community Wildfire Protection
Plan (CWPP) Orange Orange Green
Does not currently participate in Napa County
CWPP; future opportunity to integrate
protection wastewater assets
Ground Water Management
Planning / Plans
Green Green Green
Participates in regional water planning efforts
through Collection System Master Plan,
Recycled Water Strategic Plan, and WWTP
Master Plan
Climate Action Plan
Green Green Green
2023 Climate Change Mitigation Plan
addresses GHG emissions reduction goals and
adaptation
Drought Mgmt/ Contingency
Plan
Green Green Green
Participates in Napa County Drought
Contingency Plan and coordinates with City of
Napa on potable reuse studies; maintains
Water Conservation Program page and
integrates drought response with recycled
water supply
FireWise Communities within
District Yellow Yellow Green Napa Firewise Foundation; future opportunity to collaborate
Hazard-Related Public Outreach
Program
Green Green Green
Conducts outreach on drought hazard through
community events, Board updates,
newsletters, and water conservation
campaigns (Strategic Plan Goal 5)
Administrative and
Technical
Staff Capacity
Emergency Manager
Green Green Green Incident Commander (General Manager) as designated Emergency Manager
Civil Engineer Green Green Green Engineering Director/District Engineer Dedicated Public Outreach
Personnel Green Green Green Public Information and Outreach Specialist GIS Specialist and Capability Green Green Green Engineers and Technicians manage GIS Grant Manager, Writer, or
Specialist Yellow Yellow Green No dedicated grant manager; functions performed by Finance staff
Other N/A N/A N/A
Warning Systems/Services
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HMP Integration
Resource Status
Current
Mitigation
Use
Future
Opportunity Notes / Additional Detail
General
Green Green Green
Nixle / County Alert systems for general
warnings; internally uses CMMS and SCADA
alarms
Flood
Yellow Yellow Green
No dedicated flood warning system; monitors
river discharge and coordinates with
City/County flood managers
Wildfire
Yellow Yellow Green No dedicated wildfire warning system; County/CalFire alerts
Geological Hazards
Yellow Yellow Green No dedicated seismic warning system; regional/state systems (USGS ShakeAlert)
Fiscal Capabilities
Financial Resources for
Hazard Mitigation
Levy for Specific Purposes with
Voter Approval Orange Orange Yellow Not currently used
Utilities Fees Green Green Green Sewer service fees
System Development Fee Green Green Green Capacity charges on new development General Obligation Bonds to
Incur Debt Orange Orange Yellow Historically relies on pay-as-you-go financing; limited use of general obligation bonds
Special Tax Bonds to Incur Debt Orange Orange Yellow Not currently used Withheld Spending in HazardProne Areas Yellow Yellow Green No explicit policy; futue opportunity via CIP Stormwater Service Fees N/A N/A N/A Does not provide stormwater services Capital Improvement Project
Funding Green Green Green
10-Year CIP integrates asset management, I&I
reduction, recycled water, and climate
adaptation project
Education / Outreach
Capabilities
Education/Outreach
Resources
Website Dedicated to Hazard
Topics Green Green Green Website provides information on drought and water conservation
Dedicated Social Media
Green Green Green Actively uses Facebook to communicate about drought
Hazard Info. Avail. at Library/
Planning Desk N/A N/A N/A Not within district scope
Annual Public Safety Events
Green Green Green
Regularly participates in community fairs,
water conservation days, and drought
outreach
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