Adopted Safety Element Vulnerability Assessment - January 31, 2023

City of Orinda

Vulnerability Assessment

January 2023

1. I NTRODUCTION

The City of Orinda (City) prepared this Climate Change Vulnerability Assessment Report (Vulnerability Assessment) in conformance with State of California requirements to assess and address the City’s climate change vulnerability, adaptive capacity, and resilience as part of the General Plan Safety Element Update. The goal of this requirement is to enable the City to prepare for, respond to, withstand, and recover from disruptions created or caused by climate change. The Vulnerability Assessment acts as a foundation for preparation of adaptation and resilience policies for inclusion in the General Plan Safety Element by identifying a set of priority vulnerabilities in Orinda. This report presents the regulatory framework and method for preparing a Vulnerability Assessment, the climate change hazards affecting Orinda’s populations and assets, a summary of the Vulnerability Assessment results, and implications for the Safety Element Update.

1.1 Community Profile

Orinda is a low-density, predominately residential community in the hills and woodlands of the East Bay region.

The City of Orinda is in the western portion of Contra Costa County, situated in the San Francisco Bay Area. Orinda is bordered by the Briones Reservoir to the north, San Pablo Reservoir to the northwest, Oakland Hills to the west, the City of Lafayette to the east, and the Town of Moraga to the south. The City of Orinda covers approximately 12.7 square miles The topography in Orinda varies from low-lying valleys to rolling hills. The crests of the hills range in elevation from 1,000 to 1,700 feet. Orinda is a low-density, primarily residential community characterized by hilly oak woodlands and multiple creek tributaries that feed San Pablo Creek. The city is bisected by State Route (SR-) 24 and the Bay Area Rapid Transit (BART) railway, with the Theatre District commercial area and surrounding neighborhoods to the south and the Village commercial area and surrounding neighborhoods to the north.

Existing land uses in the city consist of a variety of primarily single-family residential, the downtown area (consisting of commercial, office, institutional, and multifamily residential), open space, and utility land holdings (East Bay Municipal Utility District and Pacific Gas and Electric Company). The city is also crisscrossed by several high-voltage utility line alignments due to the location in the hills along the SR-24 corridor. Orinda is a nearly built-out residential community with a compact downtown on both sides of SR-24 and large undeveloped watershed and open space lands north and west of the city

According to the 2023 City of Orinda Draft Housing Element Sixth Cycle: 2021-2029, Orinda is home to 19,078 residents (approximately 10 percent higher than in 2010) and supports 5,495 jobs. 1 Major economic sectors in Orinda include education, finance and insurance, healthcare and social assistance, and professional, scientific, and technical services. The Orinda

The median age of residents in Orinda is 48.7 years. Nearly one-quarter of Orinda residents are 65 years or older.

Union School District is the largest employer in the city with about 335 employees. 2 The Orinda Police Department, operated by the Sheriff’s Department under contract, provides law enforcement services and the Moraga-Orinda Fire District (MOFD) provides fire protection services to Orinda, Moraga, and the surrounding unincorporated areas. The Pacific Gas and Electric Company (PG&E) provide energy service to the community.

Approximately 93 percent of Orinda households own their home, compared to 55 percent of California households.

In 2019, the median age of all people in Orinda was 48.7, compared to a median age of 46.1 in 2010. In general, the population of Orinda is getting older. According to the 2016-2020 American Community Survey (ACS), approximately 23 percent of the population (4,449 persons) are senior residents (65 years or older), and approximately 22 percent of senior citizens live alone. Approximately 72 percent of Orinda residents identify as non-Hispanic White and 16 percent of residents identify as Asian. Median household income in Orinda is approximately $231,000, although approximately 400 households report annual income of less than $25,000. Approximately 93 percent of Orinda households own their home. Linguistically isolated populations primarily include those that speak Chinese (Mandarin or Cantonese), Persian, and Spanish. 3

Orinda has a Mediterranean climate, with moderate year-round temperatures. On average, annual high temperatures in Orinda range from 58 degrees Fahrenheit (°F) in January to 78°F in August. Low temperatures range from 42°F in January to 56°F in August. 4 Hot and dry Diablo winds occur in the fall and spring. Winter rains fall from November to April. The city receives an average of approximately 25 inches of precipitation annually. 5 Most precipitation falls during the winter months with rare occurrences of summer storms. Winds often come from the west, with the exception of the Diablo winds, which usually come from the northeast.

Orinda’s primary transportation access is from SR-24 SR-24 connects Orinda to SR-13, Interstate (I)880, I-580, Oakland, and Alameda County to the west, and Lafayette and I-680 to the east. Other major roadways include Camino Pablo and Moraga Way. County Connection provides local bus transit options, and BART provides regional rail transit services. Prior to the COVID-19 pandemic, approximately 57 percent of Orinda’s workforce drove alone to work and mean travel time to work was approximately 36 minutes. 6

1.2 Climate Adaptation Regulatory Framework

In 2015, the state adopted Senate Bill (SB) 379, amending Section 65302(g) of the California Government Code to require the Safety Element of the General Plan to include more information about wildfire hazards, flooding risks, and other short-term and long-term threats posed by climate change. SB 379 is the foundation for adaptation and resiliency in General Plan Safety Elements because it requires local governments to conduct vulnerability assessments as part of their longrange public safety planning efforts and to prepare adaptation and resilience goals, policies, and implementation measures that respond to the findings of the Vulnerability Assessment and protect against harm caused by climate change.

Other important updates to California Government Code Section 65302(g) related to safety elements, climate change, and resiliency and addressed in the City’s General Plan Update include SB 1241, SB 1035, SB 99, Assembly Bill (AB) 2140, and AB 747/1409.

• SB 1241 adds Section 65302(g)(3) to the California Government Code, requiring jurisdictions in a state responsibility area or very high fire hazard severity zone (FHSZ) to provide background; historical context; and goals, policies, and implementation measures to address wildfire risks in a community.

• SB 1035, which establishes Section 65302(g)(6) of the California Government Code, builds on previous legislation and requires local governments to review and update as needed their Safety Element during an update to their Housing Element or Local Hazard Mitigation Plan (LHMP) (or no less than every eight years). Any revisions should include updated information related to flood hazards, fire hazards, and climate adaptation and resilience.

• AB 2140 adds Sections 8685.9 and 65302.6 of the California Government Code, enabling cities and counties to adopt an LHMP into its Safety Element.

• SB 99 establishes Section 65302(g)(5) of the California Government Code and requires jurisdictions to review and update the Safety Element to include information identifying residential developments in hazard areas that do not have at least two emergency evacuation routes.

• AB 747 adds Section 65302.15 to the California Government Code (amended by AB 1409), requiring local governments to identify the capacity, safety, and viability of evacuation routes and locations in the Safety Element or LHMP. While the City is not yet required to undertake an AB 747 analysis, it has elected to do so to ensure a more robust and comprehensive Safety Element update.

The update to the Safety Element, including this Vulnerability Assessment, will enable the City of Orinda to meet the State’s requirements.

The California Governor’s Office of Emergency Services prepared a guidance document, the California Adaptation Planning Guide (APG) to assist communities in addressing climate adaptation and resilience and complying with Section 65302(g) of the California Government Code. The APG presents a step-by-step process for gathering the best-available climate change science, completing a climate change Vulnerability Assessment, creating adaptation strategies, and integrating those strategies into General Plans and other policy documents. The City’s Vulnerability Assessment is consistent with the guidance and recommended methods provided in the APG.

2. C LIMATE C HANGE IN O RINDA

2.1 Climate Change and Climate Stressors

Climate change is a long-term change in the average meteorological conditions in an area. The global climate is changing due to an increase in greenhouse gas (GHG) emissions that trap heat near the Earth’s surface. While some levels of these gases are necessary to maintain a comfortable temperature on Earth, an increased concentration of these gases due to human activity traps additional heat, changing Earth’s climate system in several ways. These effects of climate change are experienced in the form of climate stressors. Climate stressors are a condition or trend related to climate variability and change such as decreased precipitation or warmer temperatures that can exacerbate natural hazards. Climate stressors fall into two categories: primary climate stressors and secondary climate stressors.

As GHG emissions build in the atmosphere and global temperatures continue to rise, primary climate stressors at the local level are likely to become more severe, which in Orinda are changes in air temperature or precipitation levels. These primary climate stressors can lead to secondary climate stressors or hazards, which are events or physical conditions that have the potential to cause fatalities, injuries, property damage, infrastructure damage, agricultural losses, damage to the environment, interruption of business, and other types of harm or loss. Such secondary stressors may include wildfires, landslides, and flooding and intense precipitation. These hazards can harm populations and assets in Orinda, and in many cases, already cause harm. Populations and assets may already be subject to non-climate stressors, or trends unrelated to climate that can exacerbate climate change hazards. These non-climate stressors may include lack of funding for infrastructure maintenance, chronic health conditions or disabilities, or lack of access to lifelines.

2.2 Climate Change Modeling Considerations

The Intergovernmental Panel on Climate Change (IPCC), an organization that represents the global scientific consensus about climate change, identified four climate scenarios in the Fifth Assessment Report, also called Representative Concentration Pathways (RCPs), that can be used to project future conditions. i RCPs are labeled with different numbers (e.g., RCP 2.6, RCP 6) that refer to the increase in the amount of energy that reaches each square meter of Earth’s surface under that scenario. The four RCPs are:

i The IPCC recently released “The Physical Science Basis” of the Sixth Assessment Report that updates global climate change projections for the near-term, mid-term, and long-term based on GHG emission trends from the past decade. It moves away from using RCPs, instead using five different scenarios called “shared socioeconomic pathways,” which consider socioeconomic trends underlying each scenario. This Vulnerability Assessment does not use these updated projections because at time of writing, they are not available at a local scale. However, the IPCC report does reaffirm the use of projections comparable to RCP 8.5 as the suggested emission scenario to use for Cal-Adapt data.

• RCP 2.6: Global GHG emissions peak around 2020 and then decline quickly.

• RCP 4.5: Global GHG emissions peak around 2040 and then decline.

• RCP 6: Global emissions continue to rise until the middle of the century.

• RCP 8.5: Global emissions continue to increase at least until the end of the century.

Projections of climate hazards from Cal-Adapt and other sources rely on climate models, which are computer simulations that forecast future climate conditions under these different RCP scenarios. It is critical for the City to account for all reasonably plausible future conditions, including the most severe of plausible conditions, which will help ensure greater resiliency from climate change. Therefore, the projections in the Vulnerability Assessment use the RCP 8.5 scenario, following guidance in the APG and to be consistent with the IPCC Sixth Assessment Report. No model can project future conditions perfectly, but current models are heavily reviewed by climate scientists and can accurately reproduce observed climate conditions.

The Vulnerability Assessment also relies on the understanding that “weather” and “climate” are two different things. “Weather” describes the conditions at a particular time and place, and “climate” describes the long-term average of conditions. Because there are large variations in the weather, it is difficult to accurately project weather conditions more than a few days in advance. However, because climate is a long-term average, it can be projected out for years or decades with a high degree of accuracy. It is important to remember that, because climate is an average, it does not say whether an event will or will not occur, only how likely it is. For example, extreme heat is likely to become more frequent in Orinda, but a year with few heat waves does not mean that this projection is wrong, because the projection only says that extreme heat days are expected to occur, on average, more often than in the past.

2.3 Climate Change in California

The most accurate data for California-specific projections is available for the RCP 4.5 and RCP 8.5 scenarios. These scenarios help generate climate models, which are meant to simulate conditions across the globe. The model divides Earth’s surface into cells using a grid, and then forecasts the conditions in each square of the grid. The size of these squares makes them suitable for projecting global conditions, but they are too big to accurately model the difference in climate across smaller areas. 7 Per State guidance, these models have been “downscaled” to much finer grids, which means that they have grids that are less than four miles on each side to show projections on a county or city level. The California Fourth Climate Change Assessment and Cal-Adapt provide a foundation of climate change science and downscaling for the state. The State of California has also developed a comprehensive set of reports and tools that local jurisdictions can use to assess climate change hazards and prepare for these hazards. The State-provided reports and tools used in the Vulnerability Assessment include:

• Cal-Adapt.org

• California 4th Climate Change Assessment (statewide and regional reports) (2018)

• California Adaptation Clearinghouse

• California Adaptation Planning Guide (2020)

• California Climate Adaptation Strategy (2021)

• California Building Resilience Against Climate Effects (2018)

• California’s Wildfire and Forest Resilience Action Plan (2021)

• Defining Vulnerable Community in the Context of Climate Adaptation (2018)

• Department of Transportation Climate Change Vulnerability Assessments, District 4 (2018)

• Planning and Investing for a Resilient California (2018)

• Draft California Extreme Heat Action Plan (2022)

3. O RINDA V ULNERABILITY A S SESSMENT

In Orinda, climate change is expected to intensify many existing hazards, such as wildfire and flooding, or create new hazards, such as extreme heat and drought. The Vulnerability Assessment evaluates the projected frequency and severity of these hazards and how these hazards will affect community populations and assets.

3.1 Vulnerability Assessment Method

The Vulnerability Assessment primarily follows the recommended four-step process in the APG: (1) characterizing the community’s exposure to current and projected climate hazards; (2) identifying potential sensitivities and potential impacts to city populations and assets; (3) evaluating the current ability of the populations and assets to cope with climate impacts, also referred to as its adaptive capacity; and (4) identifying priority vulnerabilities based on systematic scoring. Figure 1 presents these steps.

Step 1. Identify Exposure

Step 2. Identify Sensitivities & Potential Impacts

Step 3. Assess Adaptive Capacity

Step 4. Prioritize Vulnerability Scoring

Step 1. Identify Exposure. The goal of the first step of the Vulnerability Assessment is to characterize the community’s exposure to current and projected climate change hazards. The climate change hazards included in the Vulnerability Assessment are drought, extreme heat and warm nights, flooding, human health hazards, landslides, severe weather, and wildfire and smoke. These hazards are discussed in more detail later in this report.

Some of the hazards are compounding climate change effects where one climate change hazard leads to another more severe disaster, also known as “cascading effects.” Figure 2 provides an example of these cascading effects.

FIGURE 1 CALIFORNIA ADAPTATION PLANNING GUIDE RECOMMENDED MODEL

Changes in precipitation and temperature

FIGURE 2 EXAMPLE OF CASCADING EFFECTS

Drought conditions occur, landscapes become more flammable

Wildfires spread faster with drier/more droughttolerant fuels

Wildfires modify supportive vegetation on hillsides

Increase susceptibility to landslides due to vegetation changes that destabilize slope

The climate change hazard data was derived from best available downscaled data, including the state Cal-Adapt database, the APG, the California Fourth Climate Change Assessment, and the Contra Costa County Local Hazard Mitigation Plan (adopted in 2018)

Step 2. Identify Sensitivities and Potential Impacts. The second step of the Vulnerability Assessment involved evaluating potential future climate change impacts to community populations and assets. City staff first identified a comprehensive list of populations and assets to understand how susceptible different people, places, ecosystem services, and community services are affected by climate change hazards. This list includes 18 building and infrastructure types, 5 economic drivers, 5 ecosystems and natural resources, and 8 key services, as shown in Table 1 and described in more detail in Appendix A

Sensitivity: The level to which a species, natural system, or community, government, etc., would be affected by changing climate conditions.

Impact: The effects (especially the negative effects) of a hazard or other conditions associated with climate change.

Source: California Adaptation Planning Guide

Category

Populations

TABLE 1 LIST OF POPULATIONS AND ASSETS

Children (under 10)

Cost-burdened households

Households in poverty

Immigrant communities

Linguistically isolated persons

Low-income households

Bicycling and pedestrian trails

Bridges

Communication facilities

Buildings and Infrastructure

Populations or Assets

Low-resourced people of color

Persons without access to lifelines

Outdoor workers Renters

Overcrowded households

Persons experiencing homelessness

Persons with chronic illness and/or disabilities

Persons without a high school degree

Flood control and stormwater infrastructure

Government administration facilities

Hazardous materials sites

Community centers

Electrical transmission infrastructure

Cooling centers

Education

Economic Drivers

Ecosystems and Natural Resources

Key Services

Finance and insurance

Oak woodlands

Homes and residential structures

Libraries

Major roads and highways

Healthcare and social assistance

Major employers

Riparian

Grassland Scrub

Communication services

Emergency medical response

Energy delivery

Government administration and community services

Public safety response

Public transit access

Seniors (65+)

Seniors living alone

Unemployed persons

Natural gas pipelines

Parks and open space

Public safety buildings

Schools

Transit facilities

Water and wastewater infrastructure

Professional, scientific, and technical services

Wetlands and vernal pools

Solid waste removal

Water and wastewater

The evaluation of these populations and assets allowed City staff to prioritize vulnerabilities across several sectors to build resiliency for the most susceptible people and assets in the city. Some assets, such as state and regional parks, are outside the city limits but serve residents of Orinda as employment or recreation centers, and therefore were included in the assessment. Following confirmation of this list, City staff developed an applicability matrix, which looked at which hazards are likely to affect which populations and assets. For example, human health hazards are likely to affect most populations, but they would not physically affect buildings.

After the applicability review, City staff evaluated potential impacts to the applicable populatio ns and community assets. To identify how severe the impacts of each relevant hazard are on the populations and community assets, City staff considered several different questions that helped ensure the assessment broadly covered a range of potential harm, including:

• What types of potential impacts may occur?

• What is the risk of harm, including physical injury or damage, behavioral or mental harm, or loss of economic activity?

• How many people or assets may be affected?

• How soon would impacts happen and how long would they persist?

• Is there a substantial risk of death or widespread destruction?

Based on the results of the impact assessment, the City ranked each population and asset as experiencing low, medium, or high impacts for each relevant hazard. Impact is considered a negative quality, and therefore, a higher impact score means that there is a higher potential for harm to a population or asset, while a lower impact score means that there is a lower potential for harm to a population or asset.

Step 3. Assess Adaptive Capacity. As the third step of the Vulnerability Assessment, City staff evaluated each population and asset’s adaptive capacity by considering a series of questions, including:

• Are there existing programs, policies, funding, or other efforts to provide assistance, reverse or repair damage, or restore or adapt resources or assets?

• Are there existing barriers that limit response or recovery? Are these financial limitations, political challenges, lack of access to technology, or others?

• Are there alternatives in or near Orinda that community members can use? Are there redundant resources that the community can rely on in case of failure or loss of function of primary resources?

Adaptive Capacity: The “combination of the strengths, attributes, and resources available to an individual, community, society, or organization that can be used to prepare for and undertake actions to reduce adverse impacts, moderate harm, or exploit beneficial opportunities.”

Source: California Adaptation Planning Guide

Based on the results of the adaptive capacity assessment, the City ranked the adaptive capacity of each population or asset as low, medium, or high for each relevant hazard. Adaptive capacity is considered a positive attribute, so a higher adaptive capacity score will mean that a population or asset may be more adaptable to the hazard. A lower adaptive capacity score means that a population or asset may have a harder time adjusting to the changing conditions given available resources.

Step 4. Prioritize Vulnerability Scoring. To complete the Vulnerability Assessment, the City used the impact and adaptive capacity scores for each population and asset for each relevant hazard to determine a vulnerability score. The vulnerability score reflects how susceptible a population or asset is to harm from a particular hazard. Vulnerability is assessed on a scale of low, medium, and high. Low vulnerability does not mean that the population or asset will be unaffected by climate change, but that the effects are likely to be less substantial.

Vulnerability: The degree to which natural, built, and human systems are susceptible “…to harm from exposure to stresses associated with environmental and social change and from the absence of capacity to adapt.”

Source: California Adaptation Planning Guide

The matrix in Figure 3 shows how impact and adaptive capacity scores combine and translate into a vulnerability score. For example, extreme heat is expected to create a high impact on energy delivery services as mechanical failures, heat damage, and high demand for electricity from cooling equipment can disrupt this service. Adaptive capacity is expected to be low because many community members need to use more electricity on extreme heat days to keep cool and retrofitting electrical equipment can be expensive. Therefore, energy delivery services would have a vulnerability score of V5 to extreme heat.

3.2 Climate Change Hazards and Key Vulnerabilities

The Vulnerability Assessment assigns vulnerability scores to 282 unique pairings of 53 populations and assets for each of the relevant 7 hazards. This section describes the climate change hazards projected to occur at the local level and discusses the significant vulnerabilities created by those hazards.

• Low-resourced people of color, seniors living alone, households in poverty, and persons with chronic illnesses and/or disabilities are the most vulnerable to climate change hazards. Persons who are unable to drive, lack access to reliable transportation, or are in areas with limited roadway access are particularly susceptible.

FIGURE 3

VULNERABILITY SCORING MATRIX

• Power lines are among the most vulnerable structures, as they connect to Orinda by passing through areas of very high wildfire risk, elevated landslide risks, and locations subject to severe weather and high winds. Other vulnerable buildings and infrastructure include major roads and highways and homes and residential structures.

• Riparian habitat and wetlands and vernal pools are the most vulnerable ecosystems and natural resources. Such ecosystems are already limited and threatened by other environmental factors, making them particularly susceptible to climate change

• Energy delivery, public transit access, and water and wastewater treatment are the most vulnerable key services.

For a complete list of vulnerability scores, see Appendix B.

Drought

A drought occurs when conditions are drier than normal for an extended period, making less water available for people and ecosystems. Droughts are a regular occurrence in California; however, scientists expect that climate change will lead to more frequent and more intense droughts statewide. As of March 2022, Orinda and the greater Contra County region, and State of California are in severe drought conditions. 8 Overall, precipitation events are expected to become less frequent and more intense, which in turn may lead to more frequent and intense drought periods. In an earlycentury drought (2023 to 2042), the City could experience a drop in average precipitation from an average of 30.4 inches per year to an average of 26.2 inches per year. 9 In a late-century drought (2051 to 2070), precipitation could also drop to an average of 26.2 inches per year. 10 As described below, average temperatures and average number of extreme heat days are both projected to increase in Orinda over the course of this century, which may also facilitate drought conditions.

Orinda’s water supply comes from the East Bay Municipal Utility District (EBMUD) and is delivered by the Orinda Water Treatment Plant. EBMUD’s water supply begins at the Mokelumne River watershed in the Sierra Nevada and extends 90 miles to the East Bay, passing through the Sacramento-San Joaquin Delta. Snowmelt in the Sierra Nevada accounts for approximately 90 percent of EBMUD’s drinking water supply, with other sources, such as local supplies and the Sacramento River, accounting for the remaining supplies.

Snowpack levels in the Sierra Nevada dropped by 25 percent during the 2011 to 2016 drought, and average springtime snowpack is expected to drop by up to 64 percent by 2100. 11 In April 2022, the California Department of Water Resources noted that statewide snowpack is only 38 percent of normal. 12 During drought conditions, water stored in Pardee Reservoir could decrease due to lack of rainfall and reduction in snowpack because of higher temperatures, causing water shortages during extended drought conditions or price hikes that could increase economic instability of low-income and low-resourced residents.

EBMUD does have plans in place that include increased water conservation programs, sourcing water from other sources, and other contingency efforts. While such plans help provide increased resilience to drought conditions, there remains some possibility of disruption to the local water supplies. Increases in recycled water supplies are an option, although at present they cannot replace local potable water needs. Despite the high level of median household income in Orinda, some lower-

income households and businesses may be challenged to upgrade fixtures and appliances to waterefficient versions. Fines for excess water use can also have a disproportionate effect on lower-income persons.

Orinda’s habitats most vulnerable to drought are chaparral, riparian, and wetland habitats, which depend on water from rainfall and groundwater. In chaparral ecosystems, drought can weaken plant and tree species, causing habitat dieback or conversion to grassland or other vegetation types that may be more suited to less rainfall. 13 Drought conditions can also dry out vegetation and increase wildfire conditions, which could put a strain on firefighting equipment and personnel, in addition to the threat of injury, loss of life, or property damage or destruction. Trees may not receive adequate water during drought periods, which can lead to pests and diseases destroying important habitat and can make trees more vulnerable to wildfire.

Drought conditions can cause smaller streams to run dry, which can subsequently harm the plants and animal habitat within riverine and aquatic ecosystems. Soil erosion can also occur on the banks of streams 14 Wetlands can be directly affected by reduced water quantity and quality due to drought conditions. Drought can contribute to algal blooms, low streamflow, degraded water quality, higher temperatures, and increased erosion in both Delta and inland wetland habitats.

Extreme Heat and Warm Nights

Extreme heat occurs when temperatures rise significantly above normal levels. In Orinda, an extreme heat day occurs when temperatures reach above 91.4°F. As shown in Figure 4, the number of extreme heat days in Orinda is projected to increase from an average of 4 days historically, to an average of 15 extreme heat days per year by mid-century (2035 to 2064), and an average of 27 by the end of the century (2070 to 2099). 15

Sources: Cal-Adapt, 2022; National Weather Service, 2022.

FIGURE 4 PROJECTED EXTREME HEAT DAYS IN ORINDA

Extreme heat can also occur in the form of warmer nights, as temperatures do not cool down overnight and provide relief from the heat. In Orinda, a warm night occurs when the temperature stays above 58.3°F. As shown in Figure 5, the number of warm nights in Orinda is projected to increase from an average of 6 historically to an average of 53 warm nights per year by mid-century, and an average of 117 warm nights per year by the end of the century.

FIGURE 5 PROJECTED WARM NIGHTS IN ORINDA

Note that the visual change in Figures 4 and 5 from 2020 to 2021 is due to a need to use multiple sources for the observed data. The data from 1950 to 2005 and 2020 to 2100 are derived from CalAdapt. The data from 2006 to 2020 are from the National Weather Service. Therefore, the observed extreme heat days and warm nights differ slightly from the projections. In recent years, the observations exceed what the average projections are showing.

Extreme heat can cause heat-related illnesses, such as heat cramps, heat exhaustion, and heat stroke, in addition to worsening respiratory and cardiovascular conditions. The most vulnerable populations are those that spend a disproportionately high amount of time outside, such as children, outdoor workers, immigrant communities, and persons experiencing homelessness. Additionally, persons with chronic illnesses, populations with existing pollution burdens, and senior citizens are highly vulnerable to extreme heat due to potential existing health conditions. Persons with financial instability, or who are low-resourced are also highly vulnerable due to a lack of financial resources to prepare for or respond to extreme heat conditions.

Some homes in Orinda may lack air conditioning or effective insulation, and as a result, people living in these homes may be more susceptible to harm from extreme heat events. Approximately 83 percent of Orinda’s housing units were built prior to 1980, before the establishment of modern building codes. 16 The City has one designated cooling center at the Orinda Public Library , although this facility is not always open when it is needed. Residents may not be able to cool homes or keep medications cooled if extreme heat events cause rolling blackouts. When extreme heat is combined with severe fire weather and high winds, electricity may be turned off through Public Safety Power

Shutoff (PSPS) events, and residents may not be able to cool their homes during extreme heat days. Rolling blackouts may also cause food loss due to lack of refrigeration when the power is turned off, which could harm persons with financial instability or limited income.

Energy delivery services, and associated infrastructure, are highly vulnerable to extreme heat, as high temperatures can stress and overload the regional grid, causing power outages and damage to the transmission lines. Transportation infrastructure, such as evacuation routes, major roadways and highways, and railways, are also highly vulnerable to extreme heat and prolonged periods of high temperatures, which can crack, heave, or deform roadway and railway materials, damaging major roads, transit corridors, and evacuation routes or making them difficult to drive or travel on. 17

Additional vulnerabilities include the following:

• Outdoor recreation, as people may be deterred from recreating outdoors in high temperatures.

• Wetlands and vernal pools habitat, which can alter species composition and cause harmful algal growth that can harm both plant and wildlife species as temperatures increase.

• Scrub habitat, which can experience species composition shifts with higher average temperatures.

• Public transit access, as extreme heat reduces ridership of County Connection and BART since it may be more difficult to wait outside for the bus or train.

Flooding

Inland flooding can cause significant harm to buildings, people, and infrastructure. Floodwater can be deep enough to drown people and may move fast enough to carry people or heavy objects (such as cars) away. Flooding can be caused by heavy rainfall, long periods of moderate rainfall, or clogged drains during periods of light rainfall. In rare instances, a break in a dam holding back water in a reservoir, such as Briones Reservoir or Lake Cascade could cause devastating flooding. Storm drainage systems throughout the city collect stormwater runoff and convey water to prevent flooding, although these systems are typically designed based on winter storms recorded in the past and may not be designed to accommodate more intense storms.

Floods are expected to occur more frequently as a result of climate change, affecting what the community understands as a “normal” flood. For example, what is currently considered a 100-year flood, or a flood that has a 1-percent chance of occurring annually, may occur every 20 or 50 years. Figure 6 shows that the flood hazard areas are primarily along San Pablo Creek, Lauterwasser Creek, as well as other low-lying areas in the southeastern portion of the city.

FIGURE 6

FLOOD HAZARD ZONES

The Federal Emergency Management Agency (FEMA) defines a 100-year floodplain as an area with a one in 100-year chance, or 1 percent, annual chance of flooding in any given year and a 500-year floodplain as an area with a one in 500-year, or 0.2 percent, annual chance of flooding in any given year.

Several populations and assets face particularly high risks from flooding events.

• Persons experiencing homelessness, households in poverty, immigrant communities, lowincome households, and low-resourced people of color are severely vulnerable to flooding, as they may live in or near flood hazard areas, lack financial resources to protect their homes, or be ineligible for grant funding to recover from flood damage to their homes.

• Persons with limited mobility and those without access to lifelines (persons without access to a car, transit, or communication systems) may have difficulty evacuating prior to a flooding event, and therefore are also highly vulnerable.

• Outdoor workers may be unable to travel to work during flooding events and worksites may be inundated by floodwaters, reducing employment opportunities.

• Transportation infrastructure, including major roads, highways, bridges, railways, evacuation routes, and transit facilities, can be inundated, blocked, and damaged by floodwaters along the San Pablo Creek.

• Employees may be unable to travel to work due to inundation of transportation infrastructure, disrupting economic drivers, public transit access, major employers, public safety response, and other services.

• Heavy rainfall and subsequent flooding can disrupt water and wastewater services, causing the water and wastewater treatment plants to not function properly. This can also cause effluent to flow into the surrounding water and soil and can reduce recycled water supplies for irrigation.

• Energy delivery systems and associated infrastructure could be damaged by floodwaters, disrupting service for hours or days depending on the severity.

• Flooding may also inundate areas with higher soil or groundwater pollution burdens, causing toxic chemicals and contaminants to spread into the water and soil. 18

• Flood-control infrastructure may fail if floodwaters exceed the capacity of the infrastructure.

• Homes and residential structures can be damaged, destroyed, or have mold and mildew growth from standing water after flooding.

• Commercial and municipal buildings could become unusable if damaged by flooding

Human Health Hazards

Human health hazards are bacteria, viruses, parasites, and other organisms that can cause diseases and illness in people. Some of these diseases may only cause a mild inconvenience, but others are potentially life threatening. Animals such as mice and rats, ticks, and mosquitos can and often carry these diseases. Warmer temperatures and high levels of precipitation can lead to increased populations of disease-carrying animals, creating a greater risk of disease and increased rates of

infection. Other human health hazards can include poor air quality, which can affect respiratory systems of those exposed for prolonged periods.

Populations most vulnerable to human health hazards are those who spend a disproportionate amount of time outdoors (such as persons experiencing homelessness), those with fragile immune systems or existing illnesses (which may include persons with chronic illnesses, seniors, and pollutionburdened populations), and those who may live in sub-standard housing or not have access to health insurance and medical care (households in poverty, low-resourced people of color, immigrant communities, and overcrowded households). These persons may be living in conditions that increase their chances of catching vector-borne illnesses or lack the ability to fight off infections that may occur. Many populations may also not have access to air purification systems that can filter out harmful pathogens. 19

Major employers, such as the Orinda Union School District or the Orinda County Club, could see a decline in staff attendance and patrons due to human health hazard exposure or concerns. A reduction in workers could harm local businesses or economic drivers such as healthcare and education. This was the case in 2020 and 2021, when Contra Costa County implemented school and non-essential business closures due to the COVID-19 pandemic. Emergency medical response services are also highly vulnerable to human health hazards, as they may not be able to provide adequate services if there is an influx of health-related emergencies.

Landslides

Landslides occur when a hillside becomes unstable, causing soil and rocks to slide downslope. Landslides can include rock falls, deep failures of slopes, and shallow debris flows. 20 Landslides are most common on steep slopes and hillsides made up of loose soil or other material where excavation and grading, drainage alterations, or changes in vegetation have occurred. The Vulnerability Assessment looks at landslides that are caused by precipitation, although earthquakes can also trigger landslides. Hillsides commonly absorb water, which increases instability of the slope and may increase the risk of slope failure. Steep slopes made up of loose or fractured material are more likely to slide. In some cases, the hillsides can become so saturated that slope failures can result in a mudslide and debris flows (a mixture of soil and water moving downslope). As shown in Figure 7, a majority of the city is in a high or very high landslide susceptibility area.

Landslides and mudslides can move fast enough to damage or destroy homes or other structures in their path, block roadways, and injure or kill people caught in them. The most vulnerable populations are those that may be unable to evacuate due to limited mobility, lack of access to a vehicle or communication, or low-resourced populations that may prevent awareness and response to emergency notifications. Infrastructure, such as electrical transmission lines and water or wastewater infrastructure, can break or malfunction if the soil supporting them fails. This can lead to disruptions in energy delivery and water or wastewater services. Major transportation infrastructure, such as roadways, bridges, and evacuation routes, can be blocked or damaged by landslides preventing public transit access locally and regionally. Many homes and residential structures are in landslide-prone areas, which can be damaged or destroyed by landslides and debris flows.

Severe Weather

Severe weather is generally any destructive weather event, but usually occurs in Orinda as localized storms that bring heavy rain, hail, lightning, and strong winds. Severe weather is usually caused by intense storm systems, although types of strong winds can occur without a storm. The connection between climate change and severe weather is not as well established as other hazards, but new evidence suggests that these forms of severe weather may occur more often than in the past. 21

Heavy rainfall can cause flash floods and ponding in low-lying areas of the city. The greatest risk from flash floods is occurrence with little to no warning. Localized flooding also occurs in Orinda at various times throughout the year, especially along San Pablo Creek. Hail and lightning can damage the buildings and infrastructure supporting economic sectors and key services within the city.

Severe winds, such as the Diablo winds, tend to be most frequent during the fall and spring and can have average speeds of 40 miles per hour. Diablo winds come from the north and northeast, carrying extremely dry air at a high velocity. These winds can destroy buildings, knock over trees, damage power lines and electrical equipment, and fan small sparks into large wildfires in the region. High winds, particularly in combination with hot and dry conditions, can also cause PG&E to enact a Public Safety Power Shutoff (PSPS) event to prevent sparking of power lines. During these events, residents and businesses may lose power for hours or days depending on the severity. During power outages, businesses may be forced to close, causing economic harm. Residents can lose access to communication, suffer economic harm (such as food in a refrigerator spoiling), or experience potential health impacts if they rely on a medical device and do not have a backup source of power.

Lightning is relatively rare in Orinda. The area may see only a few lightning storms or none at all each year. Orinda, like most of California, records less than one lightning strike per square mile annually. However, when lightning does occur, it can cause significant harm, including setting fires. Ten of California’s 20 largest wildfires, six of the most destructive, and three of the deadliest were at least partially caused by lightning strikes. Lightning can also cause trees to fall on power lines, buildings, or cars. Although rare, people can be directly struck by lightning, which can cause injury or death.

The most vulnerable to severe weather are those who may be directly exposed to the hazard, such as outdoor workers and persons experiencing homelessness; those who may live in less structurally resilient buildings, such as households in poverty, immigrant communities, persons with chronic illnesses and/or disabilities, and low-resourced people of color; and those who may have difficulty preparing or responding to severe weather due to mobility or language barriers. These populations include persons without access to transportation or communication and seniors living alone.

Buildings and infrastructure, such as bridges, evacuation routes and roadways, flood-control structures, and residential structures are highly vulnerable to severe weather, and they can be damaged by high winds, heavy rainfall, and debris carried by severe storms. Heavy rainfall and severe winds that damage or block transportation systems can also disrupt public transit services, which can be delayed or suspended for days or weeks depending on the severity of the damage.

Extreme winds and heavy rainfall can also harm ecosystems by causing large volumes of sediment to flow into riparian ecosystems, trees to fall in riparian habitat, and sudden oak death to spread more quickly through oak woodland forests. Extreme heat and drought conditions may weaken natural ecosystems and prevent them from recovering from severe weather events.

Wildfire and Smoke

Figure 8 shows the FHSZs in and surrounding Orinda, which include very high FHSZs in the local responsibility area, as well as high and very high FHSZs in the surrounding state responsibility area. Areas in the northwest and central northern portion of the city are within a very high FHSZ. Many of these high-risk areas are also the most difficult to access, as they are at the end of narrow, winding roads bordering undeveloped hillsides. In addition, areas adjacent to the city that are susceptible to wildfires are also of concern as these conditions could exacerbate vulnerabilities within the city. The city is also within the wildland-urban interface, which increases the risk of wildfires spreading through the community. As shown in Figure 9, the wildland-urban interface in Orinda, as designated by MOFD, covers most of the community, except for the areas immediately around the BART station and the far southeast corner of Orinda. The wildland-urban interface is a zone of transition between natural vegetation and developed lands where wildfires can move from burning just vegetation to also damaging buildings and infrastructure.

CAL FIRE Wildland-Urban Interface

As shown on Figure 9, the CAL FIRE designated wildlandurban interface is made up of three distinct zones:

Wildfires are a regular feature of the landscape in much of California. They can be sparked by lightning, malfunctioning equipment, vehicle crashes, or many other causes. Warmer temperatures, an increase in drought conditions, and extreme wind events, are likely to create more fuel for fires in natural and rural areas, leading to a greater chance that a spark will grow into a potentially dangerous blaze. Climate change is also expected to extend the fire season throughout much (or even all) of the year. Smoke from wildfires, both locally and elsewhere in northern California, also creates a significant health risk in the region. Because wildfires burn the trees and other vegetation that help stabilize a hillside and absorb water, more areas burned by fire may also lead to an increase in landslides in existing landslide-prone areas.

1. Intermix Zone. Housing development or improved parcels interspersed in an area dominated by wildland vegetation subject to wildfire.

2. Interface Zones. Dense housing next to vegetation, but not dominated by wildland vegetation, that can burn in a wildfire.

3. Influence Zone. Wildfiresusceptible vegetation within 1.5 miles from the wildland-urban interface or wildland-urban intermix zones.

Source: CAL FIRE. 2019. Wildland Urban Interface. https://frap.fire.ca.gov/media/10300/wui _19_ada.pdf

As shown in Figure 8 and Figure 9, several building types are in very high FHSZs and the wildlandurban interface areas. The portion of northwestern Orinda that is within a very high FHSZ contains primarily residential land uses. Homes can be damaged or destroyed by wildfires, rendering the structure uninhabitable and reducing the number of housing units within the city. Indoor air quality can be reduced if smoke flows into homes and residential structures, potentially damaging the structure and internal contents. Schools including Sleepy Hollow Elementary, Wagner Ranch Elementary, Orinda Intermediate, Glorietta Elementary, Del Rey Elementary, and Miramonte High School are within wildfire-prone areas and can be damaged or destroyed by a wildfire. The Orinda Water Treatment Plant is in a wildfire-prone area, and this facility can be damaged or ash could infiltrate the water system, disrupting the water treatment process and water delivery services throughout the city.

Nearly all populations within Orinda have a high or severe vulnerability to wildfire and smoke conditions. Those with existing health issues or limited mobility are particularly vulnerable due to the inability to quickly evacuate during a wildfire and additional illnesses that can occur due to smoke conditions. Smoke conditions, even from fires far away from Orinda, can also prevent residents from accessing public transit, due to unhealthy air quality, and ash from wildfires can degrade water supplies. Immigrant communities and low-resourced people of color may live in less-resilient structures or rental units where they do not have the ability to prepare their homes, and their homes are more likely to burn down in the event of a wildfire. These persons may be ineligible for or lack the time and resources to rebuild and recover from wildfires.

The entire energy delivery system, including electric transmission lines, can be damaged by wildfires. Planned PSPS events to prevent wildfires and damage to the energy delivery system have already impacted persons who depend on electricity for air conditioning or their medically necessary equipment.

Major roads and highways, including those that serve as evacuation routes and the bridges that connect these roadways, can be blocked by wildfire flames or debris, making it difficult for residents to evacuate and emergency personnel to reach certain areas of the city. The railway that provides services for BART can be damaged or blocked by wildfires, disrupting public transit access.

Wildfires in the city can also prevent visitors from traveling to the city to participate in outdoor recreation activities in nearby regional parks. Although the economy can likely recover from these events, repetitive wildfire and smoke events may make recovery difficult in the recreation sector. Chaparral habitat, although somewhat adapted to wildfires, can be substantially harmed by more frequent and severe fires that do not let the ecosystems recover. 22

MOFD has been proactive in addressing wildfire concerns in and around Orinda. MOFD regularly proposes, and the City has adopted, a stringent building code that applies citywide, requiring newly constructed buildings to meet elevated standards for building materials, landscaping, and operations. Other programs include a requirement that sprinkler systems be installed in many existing buildings, a program to provide free wood-chipping services to community members, inspecting defensible space in the community, and many others. These efforts have helped to increase adaptive capacity against wildfires in Orinda and provide a substantial benefit to the community, although wildfire remains a hazard of substantial concern.

In addition, the City has initiated a number of efforts to prevent wildfires and to be better equipped to address emergencies. The following list provides examples of several efforts that have been funded by Measure R:

• Roadside fuel reduction and vegetation management.

• Home Evaluation program that gives property owners a customized checklist of vegetation management and home-hardening tasks.

• Creating an incentive program and other resources to assist residents in implementing their home evaluation checklist.

• Offering chippers in each neighborhood twice yearly.

• Education and outreach for wildfire prevention and preparedness.

FIGURE 8 FIRE HAZARD SEVERITY ZONE

FIGURE 9 WILDLAND-URBAN INTERFACE AREAS

4. S AFETY E LEMENT U PDATE I MPLICATIONS

4.1 Equity and Uncertainty

When addressing vulnerability and adaptation through general plan policies and the associated implementation plan, the APG and General Plan Guidelines recommend consideration of equity and uncertainty.

Equity means that all people are justly and fairly included in society, and that everyone is able to participate, prosper, and achieve their full potential. Equitable climate adaptation planning involves identifying persons who are most vulnerable to climate change hazards, and ensuring that the planning process, distribution of resources, and efforts to address systematic wrongs are all conducted in an equitable manner. This Vulnerability Assessment identifies 17 potentially vulnerable populations and assesses climate change impacts and the ability of these populations to prepare for, respond to, and recover from climate change hazards (see list in Vulnerability Assessment Method section). Based on the results, nearly all of the populations are highly vulnerable to multiple hazards. Many of these groups may make up a relatively small part of Orinda’s population. Although their unique vulnerabilities may not be shared by most community members, addressing the vulnerabilities of smaller populations is important for addressing equity considerations in Orinda.

Uncertainty is the second component to consider when determining how hazardous conditions may affect Orinda. Climate change is driven by the concentration of GHGs in the atmosphere, which is affected by how our communities use resources and how we regulate those uses through local, state, federal, and international GHG-reduction goals, regulations, plans, and programs As more action is taken to reduce GHG emissions, the less severe the effects of climate change are expected to be. Climate change models consider the concentrations of atmospheric GHG emissions and the changes in these levels over time to project future extent or intensity of hazardous events.

Even with the extensive modeling, potential impacts are projections of more likely future conditions and are not certain. Similarly, there is also substantial uncertainty about the future state of technology, socioeconomic conditions, and other factors. According to recent studies, the best approach to uncertainty is to minimize inaction by developing “no regrets” strategies that are beneficial without the presence of climate change and where the costs are low compared to the benefits. The State and the City have ample evidence to support science-based policy and decisionmaking.

4.2 Opportunities

Orinda currently experiences a wide range of climate change hazards that are projected to increase in frequency and intensity in the future. The Safety Element of the General Plan is required to integrate adaptation and resilience measures into the update process that will help the community prepare for, respond to, and recover from climate change hazards, which will help to reduce their overall vulnerability. The Safety Element’s goals, policies, and implementation actions can provide resilience strategies that support both reduced impacts and improved adaptive capacity of the

community to climate change-related hazards, along with policies on required hazards, such as flooding, fire, and geologic hazards. Policies within this element can ensure that health and safety concerns of the community are met, even with an increase in frequency and intensity of climate change hazards. Examples of specific policies or implementation actions could include:

• Create an extreme heat response plan that includes establishment of equitably located community cooling centers and temperature triggers for when they will open, weatherization of City buildings, and cooling strategies for persons engaged in outdoor work and persons experiencing homelessness.

• Connect residents and business owners to programs and services that provide funding resources for economically disadvantaged households and businesses to conduct energyefficiency, weatherization, and code compliance retrofits.

• Coordinate with MOFD and the Diablo Firesafe Council and other resources to assist residents in obtaining funding to conduct vegetation management and home-hardening initiatives on private property.

• Provide alerts about potential, developing, and ongoing emergency situations through extensive early-warning and notification systems that convey information to all residents, in multiple languages and formats to ensure it is widely accessible.

• Develop an evacuation assistance program, in coordination with County Connection, paratransit, and dial-a-ride agencies, to help those with limited mobility or lack access to a vehicle to effectively evacuate.

• Require new development within a designated floodplain or FHSZ to submit fire and/or flood safety plan for approval by MOFD and Floodplain Administrator.

• Ensure evacuation routes remain open and functional during emergencies, including hardening or raising roadways, using heat-resistant materials to prevent buckling of pavement, and implementing one-way travel during evacuations.

• Promote water conservation measures, low-impact development, and green infrastructure that can help convey stormwater and reduce impacts from both drought and flooding.

• Create redundancies in the communication and electricity infrastructure by providing sustainable back-up power supplies for public and government facilities.

The Urban Sustainability Network’s Resilience Hub White Paper and Resilience Hubs website (http://resilience-hub.org/) also provides a key resilience strategy for increasing resilience throughout the city: the integration of physical and virtual resilience hubs. These can serve as centralized locations for resources about climate change, opportunities to reduce emissions, and techniques to increase resilience, showcases for sustainability, energy-efficiency, and low carbon building, and to help residents obtain essential resources and information during and after a disaster. Examples of specific implementation actions could include:

• Identify existing facilities to serve as resilience hubs and cooling centers that open during emergencies or specific temperature triggers for residents to go to seek refuge from extreme heat days or emergency shelter.

• Coordinate with emergency management services to establish backup power, preferably from renewable energy sources, and water resources at emergency shelters, resilience hubs, and cooling centers in case of power outages.

4.3 Resilience in Other Plans, Programs, and Projects

Resilience should not be limited to the General Plan. Adaptation and resilience rely on a crossdepartment, multidisciplinary approach to successful implementation. The City should consider how adaptation and resilience can also be incorporated into other City plans, codes, projects, and implementation programs. Addressing climate change hazard events in the General Plan can support other essential safety documents, such as the Contra Costa County Local Hazard Mitigation Plan The Contra Costa County Local Hazard Mitigation Plan can include mitigation actions and projects to implement Safety Element policies and directly address key vulnerabilities identified in the Vulnerability Assessment. Mitigation actions can include the following:

• Identifying existing facilities to be upgraded to become resilience hubs and obtaining funding to create these facilities.

• Conducting vegetation management along city roadways and near City-owned buildings.

• Establishing renewable back-up energy supplies at critical facilities throughout the city.

• Constructing natural flood barriers or green infrastructure to convey and absorb water to reduce flooding.

Development standards such as residential building codes for buildings in flood zones and development of adequate evacuation routes can be integrated into the Orinda Municipal Code. Policies that focus on emergency response to hazards can be included in an evacuation plan or an emergency operations plan. Policies related to drought and flooding may be integrated into the Contra Costa Water District Urban Water Management Plan. Furthermore, programs such as the Orinda Municipal Code and Capital Improvement Program can help implement the resilience policies developed in the Safety Element and Hazard Mitigation Plan through specific projects, development codes, and budgeting.

5. C ONCLUSION

The Vulnerability Assessment identifies which hazards are expected to harm sensitive populations and assets, and which assets are most vulnerable to various hazards that are projected to intensify with climate change. A comprehensive set of results is in Appendix B. Understanding how climate change will affect the community and identifying the vulnerable populations and assets will enable Orinda to implement effective GHG-reduction measures and climate adaptation strategies to create a safer, more sustainable, and healthier community.

As the climate continues to change and GHG emissions rise, climate change hazards will continue to harm populations, infrastructure and buildings, economic drivers, and key community services in Orinda. The Safety Element Update will integrate adaptation strategies into goals, policies, and implementation measures that will help increase resiliency and reduce vulnerability throughout the city.

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A PPENDIX A: L IST OF P OPULATIONS AND A SSETS

List of Items Included in the Orinda Vulnerability Assessment

The following populations and community assets were assessed as part of the Vulnerability Assessment.

Populations

The City collected population data from the U.S. Census, the California Healthy Places Index, the Contra Costa County Homeless Point-in-Time Count, and the General Plan. These 17 populations include:

• Children (under 10).

• Cost-burdened households: households paying 30 percent or more of their income towards housing expenses. 23

• Households in poverty: households with an income below the poverty line, which is $26,500 for a household of four. 24

• Immigrant communities.

• Linguistically isolated persons: especially Spanish, Farsi, and Chinese (Mandarin or Cantonese).

• Low-income households: The State identifies $109,600 as the low-income threshold for a household of four people in Contra Costa County in 2021. 25

• Low-resourced people of color: persons identifying as a member of a racial and/or ethnic group and facing limited access to resources, such as financial, social, healthcare, or educational assistance. 26, 27

• Outdoor workers: workers in construction, outdoor recreation, etc.

• Overcrowded households: Housing units that have more than 1.0 persons or more per room (excluding bathrooms and kitchens).

• Persons experiencing homelessness: 2020 Point-in-Time count reported 1,570 unsheltered, 707 sheltered, and 2,277 total persons experiencing homelessness in the Contra Costa County The report noted one homeless individual within the City of Orinda 28

• Persons with chronic illness and/or disabilities.

• Persons without a high school degree.

• Persons without access to lifelines: Persons without reliable access to a car, transit, or communication systems.

• Renters.

• Seniors (65+).

• Seniors living alone.

• Unemployed persons.

Buildings and Infrastructure

The City identified key community buildings and infrastructure using state and local geographic information system (GIS) data and the Contra Costa County Local Hazard Mitigation Plan. These 18 assets include:

• Bicycling and pedestrian trails.

• Bridges: Four state highway bridges, five local bridges. (Source: Caltrans)

• Communication facilities: Cell towers, radio sites, etc.

• Community centers: Orinda Community Center, Ranch House at Wilder Park, Wagner Ranch Club.

• Electrical transmission infrastructure

• Transmission Lines: PG&E.

• Substations: Two PG&E substations. (Source: California Energy Commission)

• Cooling centers: Orinda Library, others as identified.

• Flood control and stormwater infrastructure

• Government administration facilities: City Hall

• Hazardous materials sites: Three active sites within the city (Gateway Valley, Orinda Cleaners, Orinda Motors). (Source: California Department of Toxic Substances and Controls).

• Homes and residential structures

• Libraries: Orinda Library (Contra Costa County Library)

• Major roads and highways

• State: SR-24.

• Local: Camino Pablo, Moraga Way.

• Natural gas pipelines: PG&E.

• Parks and Open Space

• Orinda City Parks: Orinda Sports Field, Pine Grove Park, Wilder Sports Field, Orinda Community Park, Orinda Oaks Park.

• Contra Costa County Parks: Siesta Valley Recreation Area.

• School Parks: Del Rey School park/field, Glorietta School park/field, Orinda Intermediate School park/field, Sleepy Hollow School park/field, Wagner Ranch School park/field, Miramonte High School fields.

• Public safety buildings:

• Police: Orinda Police Department headquarters.

• Fire: Moraga-Orinda Fire District Fire Stations 43, 44, and 45.

• Schools: 5 Orinda Union School District Schools, 1 Acalanes Union High School District schools, 8 private schools.

• Transit facilities: BART rail and station, County Connection stops.

• Water and wastewater infrastructure: Orinda Public Works and Engineering Department, East Bay Municipal Utility District, Orinda Water Treatment Plant.

Economic Drivers

The City identified local economic drivers based on the City of Orinda Comprehensive Annual Financial Report, published in January 2021. These five assets include:

• Education

• Finance and insurance

• Healthcare and social assistance

• Major employers: Orinda Union School District, Miramonte High School, Orinda Country Club, Safeway, Orinda Care Center, Moraga-Orinda Fire District, EBMUD, Casa Orinda, City of Orinda, John Muir Physician Network, Sleepy Hollow Swim & Tennis, Litman Gregory Asset Management, Orinda Academy

• Professional, scientific, and technical services

Ecosystems and Natural Resources

The City identified key community ecosystems and natural resources according to the Environmental Resources chapter of the existing General Plan and information from the California Department of Forestry and Fire Protection’s (CAL FIRE) Fire and Resource Assessment Program (FRAP). These five resource types include:

• Oak woodlands

• Grassland

• Riparian

• Scrub

• Wetlands and vernal pools

Key Services

These assets reflect typical services provided in cities throughout California, which are supported by the infrastructure and buildings listed previously. The vulnerability of community services is assessed in terms of each service’s ability to remain operational in the face of exposure to each climate hazard. The operational integrity of community services depends on the continued functionality of supportive infrastructure and the health and wellbeing of the community members responsible for providing services. However, the Vulnerability Assessment assesses infrastructure and population-level vulnerability separately. These eight services include:

• Communications services: radio, television, cellular and landline phone, and internet.

• Emergency medical response: Moraga-Orinda Fire District

• Energy delivery: MCE, PG&E.

• Government administration and community services: programs, permitting centers, and other services provided to the public by the City.

• Public safety response: Orinda Police Department and Moraga-Orinda Fire District

• Public transit access: BART, County Connection (CCCTA).

• Solid waste removal: RecycleSmart, Republic Services.

• Water and wastewater treatment: East Bay Municipal Utility District, Central Contra Costa Sanitary District.

A PPENDIX B : V ULNERABILITY A SSESSMENT R ESULTS M ATRIX

The Vulnerability Assessment evaluates the impact and adaptive capacity of 53 populations and assets for each of the identified 7 climate hazards. Vulnerability scores were assigned high, medium, or low (as shown in Figure 3) to reflect how susceptible the population or asset is to the harm posed by the hazard. The City assessed 282 different pairings for vulnerability, 84 of which scored as high or severely vulnerable. The following matrix provides the scores for each population and asset to each relevant hazard. Gray cells with a dash (-) indicate that a specific hazard is not applicable to a specific population or asset, and therefore was not scored.

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CITY OF ORINDA

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E NDNOTES

1 City of Orinda. 2022. City of Orinda Housing Element 6th Cycle: 2023-2031

2 City of Orinda. 2021. Orinda Annual Comprehensive Financial Report, Year Ended June 30, 2021. https://www.cityoforinda.org/DocumentCenter/View/3626/Orinda-ACFR-FY2020-21

3 American Community Survey. 2016: 2016-2020 ACS 5-Year Estimates, Language Spoken at Home by Ability to Speak English for the Population 5 Years and Over, B16001. 2016-2020 ACS 5-Year Estimates, Income in the Past 12 Months, S1901. 2016-2020 ACS 5-Year Estimates, Demographic Characteristics of Occupied Housing Units, S2502.

4 BestPlaces. N.d. “Climate in Orinda, California.” https://www.bestplaces.net/climate/city/california/orinda.

5 National Oceanic and Atmospheric Administration. N.d. “U.S. Climate Normals Quick Access.” https://www.ncei.noaa.gov/access/us-climate-normals/#dataset=normalsannualseasonal&timeframe=15&station=US1CACC0010.

6 American Community Survey. 2019. 2019: ACS 5-Year Estimates, Commuting Characteristics by Sex, S0801. https://data.census.gov/cedsci/table?q=commute&g=1600000US0654232&tid=ACSST5Y2019.S0801.

7 Hall, Alex, Neil Berg, Katharine Reich. University of California, Los Angeles. 2018. “Los Angeles Summary Report. California’s Fourth Climate Change Assessment”. Publication number: SUM-CCCA4-2018-007.

8 National Drought Mitigation Center. University of Nebraska-Lincoln. 2022. “U.S. Drought Monitor, California.” https://droughtmonitor.unl.edu/CurrentMap/StateDroughtMonitor.aspx?CA.

9 Cal-Adapt. 2018. “Extended Drought Scenarios,” https://cal-adapt.org/tools/extended-drought/

10 Cal-Adapt. 2018. “Extended Drought Scenarios,” https://cal-adapt.org/tools/extended-drought/.

11 ARCCA. 2018. From Mountain to Cities: Exploring California’s Urban Connections to Sierra Nevada Ecosystems https://arccacalifornia.org/wpcontent/uploads/2018/08/ARCCA-UrbanRural-Whitepaper.pdf.

12 California Department of Water Resources. 2022. “Survey Finds Little Snow as Statewide Snowpack Drops to 38 Percent Following Record Dry Months.” https://water.ca.gov/News/News-Releases/2022/April-22/April-2022Snow-Survey.

13 Reynier, W.A., L.E. Hillberg, and J.M. Kershner. 2017. Southern California Chaparral Habitats: Climate Change Vulnerability Assessment Synthesis. Version 1.0. EcoAdapt, Bainbridge Island, WA.

14 US Deptartrment of Interior, Bureau of Reclamation. 2017. Bay Area Regional Reliability Drought Contingency Plan.

15 Cal-Adapt. 2018. “Extreme Heat Days & Warm Nights,” https://cal-adapt.org/tools/extreme-heat/

16 American Community Survey. 2016: 2016-2020 ACS 5-Year Estimates, Year Structure Built, B25034.

17 Caltrans, WSP. 2017. Caltrans Climate Change Vulnerability Assessment Summary Report, District 4 https://dot.ca.gov/-/media/dot-media/programs/transportation-planning/documents/2019-climate-changevulnerability-assessments/ada-remediated/d4-summary-report-a11y.pdf.

18 Roos, Michelle. 2018. “Climate Justice Summary Report”. California’s Fourth Climate Change Assessment. E4 Strategic Solutions. Publication number: SUM-CCCA4-2018-012.

19 Roos, Michelle. 2018. “Climate Justice Summary Report”. California’s Fourth Climate Change Assessment. E4 Strategic Solutions. Publication number: SUM-CCCA4-2018-012.

20 Tetra Tech. 2018. Contra Costa County Hazard Mitigation Plan https://www.contracosta.ca.gov/6842/LocalHazard-Mitigation-Plan.

21 Hall, Alex, Neil Berg, Katharine Reich. (University of California, Los Angeles). 2018. Los Angeles Summary Report. California’s Fourth Climate Change Assessment. Publication number: SUM-CCCA4-2018-007.

22 Reynier, W.A., L.E. Hillberg, and J.M. Kershner. 2017. Southern California Chaparral Habitats: Climate Change Vulnerability Assessment Synthesis. Version 1.0. EcoAdapt, Bainbridge Island, WA

23 City of Orinda. 2015. City of Orinda Housing Element 5th Cycle: 2015-2023

http://cityoforinda.org/DocumentCenter/View/92/5th-Cycle-Housing-Element?bidId=.

24 Office of the Assistant Secretary for Planning and Evaluation. 2021. “2021 Poverty Guidelines.” https://aspe.hhs.gov/topics/poverty-economic-mobility/poverty-guidelines/prior-hhs-poverty-guidelines-federalregister-references/2021-poverty-guidelines

25 California Department of Housing and Community Development. 2021. State Income Limits for 2021. https://www.hcd.ca.gov/grants-funding/income-limits/state-and-federal-income-limits/docs/income-limits2021.pdf

26 Public Health Alliance of Southern California. 2018. “Healthy Places Index.” https://map.healthyplacesindex.org/

27 Roos, Michelle. (E4 Strategic Solutions). 2018. Climate Justice Summary Report. California’s Fourth Climate Change Assessment. Publication number: SUM-CCCA4-2018-012.

28 Contra Costa Health Housing & Homeless Services. 2020. Contra Costa County: Annual Point in Time Count Report. https://cchealth.org/h3/coc/pdf/PIT-report-2020.pdf.