San Luis Obispo City Council
January 17, 2023

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A part of this increased risk from anthropogenic factors is the presence electric transmission lines that travel from power plant substations to electric distribution substations via utility easements called rights-of-way which are present throughout the state including areas around the City as show in Figure 28. To reduce the risk of power outages, damage, or wildfire, the rights-of-way are cleared of trees or vegetation that can contact the transmission line. However, the combination of dry climate conditions and the seasonal high autumn winds in California can increase the risk of trees or branches falling on transmission lines and causing power outages or wildfires. High winds can also cause power lines to contact with one another and cause electrical arcs with sparks or hot molten materials that can cause fires in dry grasses underneath transmission lines. While there are variety of factors which affect the risk of wildfires being caused by damaged transmission lines, several recent wildfires have been blamed on electrical utility infrastructure including a wildfire in San Diego County in 2007, the Thomas Fire in 2017, and the Camp Fire in 2019. As climate change contributes to drier conditions and tree mortality rates, the risk of wildfires caused by transmissions lines will increase if actions are not taken to mitigate this risk (Congressional Research Service 2019).

Wildland Urban Interface (WUI)
As shown in Figure 22, portions of the City as well as areas immediately surrounding the City limits are increasingly at risk of wildfire impacts. As noted above, climate change will increase the frequency of wildfire events and increase the severity and average acreage burned when wildfire events do occur. Buildings and structures in and near VHFHSZ are at increased risk of damage or destruction in the event of wildfire. Increased wildfire risk may also result in a loss of housing stock and reduced regional housing affordability.

To better understand how anthropogenic influences, specifically development patterns, may affect wildfire risk, the degree of urbanization within WUI zones in the City over several decades was analyzed. Processed satellite imagery from the National Land Cover Database (Dewitz 2019) was used to determine changes in several land use categories over three periods: 2001-2006, 2006-2011, and 2011-2016. Specifically, changes in high, medium, and low-intensity development and developed open space over these three time periods for each of 18 WUI zones within the City were assessed using a geographic information system (GIS) analysis. The results of the analysis are illustrated in Figure 22 and in Table 15.

Table 15 Percent Change in Developed Area for WUI Areas within the City 2001-2016 WUI Area
Percent change in developed area in the WUI
2011-2016 2006-2011 2001-2006
Highland Area - - -
Foothill Area - - -
Buena Vista Area - - -
San Luis Drive Area - - -
Lizzie/Sunset Area - - 3.2%
Flora Area - - -
Tanglewood Area - - -
Woodbridge Area - - -
Fontana Area - - -
Margarita Area 86.3% - -
Tank Farm Road Area - - 0.2%
Prefumo Canyon Area - - -
Madonna Area - 0.2% 54.3%
North Broad - - -
Stoneridge - - 1.0%
Terrace Hill - - -
Righetti South - - -
Righetti North - 1.2% -
Source: National Land Cover Database processed by Cbec eco DRAFT
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Figure 22 Changes in the
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Overall, there was limited development within the WUI for the period of 2001 – 2016, with a few prominent exceptions. The Madonna Area experienced over a 50 percent increase in developed area in the early 2000’s due to commercial and residential development on former agricultural land along Los Osos Valley Road. Secondly, the Margarita Area experienced an increase in developed area of over 85 percent in the 2011 – 2016 period as a result of residential development. These statistics represent a conservative estimate of development within the WUI areas, because areas that are classified as ‘developed open space’ may include grass and other open vegetated areas and in-fill into these zones by more intensive development is not considered. Instead, land cover needed to change from non-developed to developed for inclusion in the assessment. Increases in these WUI areas, although limited, do represent an increase in overall wildfire risk for the City, increasing the probability of ignitions that could have impacts on other portions of the City as well.

While buildings within the WUI are at risk from direct flame contact and radiant heat during wildfire events, buildings outside of the WUI are also at risk from ignition due to the spread of firebrands (or embers) that can initiate new spot fires up to one mile ahead from the main fire front. The risk of spot fires initiated by embers depends on several characteristics including fuel material type, condition of the fuel (e.g., live or dead fuels and moisture content levels), the thermal degradation characteristics of the fuel, the combustion properties of the fuel, and environmental conditions the fuel is subjected to (such as wind, relative humidity, temperature, and external heating condition) (U.S.

Department of the Interior 2019). Once embers have been transported to new locations and have the potential to cause new spot fires, there are several pathways into structures such as eaves, vents, windows, roofs, fences, and decking as well as potential fuels (e.g., mulch, landscaping, woody vegetation) surrounding structures, all of which affect the risk of new spot fires igniting. Eaves and vents are seen to be significant sources of ignition for homes during wildfire events, which have historically been included in homes for thermal efficiency and to minimize the chance of moisture buildup in attics. The location and arrangement of homes and land uses can also contribute to the overall fire risk within a community. Research has determined that fire risk within communities is primarily governed by structure-to-structure spread and can vary significantly by the density and flammability of homes and associated landscaping within the WUI (Fire Protection Research Foundation 2015).

Key Findings and Policy Considerations
 The risk of wildfire is dependent on a variety of factors not excluding biophysical factors that are affected by climate change including Resources (e.g., land use patterns, vegetation growth), Ignitions (e.g., lightning, accidental ignitions, arson), and Conditions (e.g., precipitation, wind, seasonal variation). Approximately 95 percent of wildfires in the state are caused by human ignition. However, climate change is projected to increase the frequency and severity of wildfires, when they do occur (Mann et al. 2016).  The combination of dry climate conditions and the seasonal high autumn winds in California can increase the risk of trees or branches falling on transmission lines and causing power outages or wildfires. While these events have occurred historically, the effect of climate change on biophysical features that increase the risk of wildfires (e.g., precipitation, wind, seasonal variation) will increase the frequency and severity of wildfires from transmission line ignitions.
 There was limited development within the WUI in the city for the period of 2001 – 2016, with a few prominent exceptions including the Madonna Area and the Margarita Area to the east of South Higuera Street. However, buildings outside of the WUI are also at risk from ignition due to the spread of firebrands (or embers) that can initiate new spot fires.

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WILDFIRE AND COMMUNITY RESILIENCE
Wildfire Evacuation Route Analysis
Wildfire events in or near the City, when they do occur, could result in emergency evacuations for certain areas. As show in Figure 22, the areas at highest risk from wildfire impacts are located in the WUI in the peripheral areas of the City Limits. As a result, impacts to the City’s evacuation gateways (e.g., major ingress and egress points in and out of the City) are not projected to be affected by wildfires. Wildfire events in the VHFHSZ near the Irish Hills Natural Reserve could potentially have immediate impacts to some residential areas on Royal Way, Sterling Lane and Isabella Way. Additionally, areas in the northeast of the City south of US 101 along San Luis Road are at risk from wildfire impacts and could potentially compromise evacuation management when wildfires do occur in this area. Figure 23 identifies census block groups in the City based on the percentage of vehicle access. Table 16 summarizes the number of census blocks in the City relative to households with vehicle access. Although not located adjacent to any VHFHSZ, the neighborhoods north of Foothill Boulevard include areas with higher percentage of households without access to a vehicle, likely due to the high percentage of California Polytechnic State University at San Luis Obispo (Cal Poly) students who live in these neighborhoods located adjacent to the campus. As part of Cal Poly’s emergency management planning, the University has contracted with multiple bus and shuttle companies in County to provide emergency transportation services, if needed, and worked with the County’s Office of Emergency Services to ensure transportation resources would be available during large scale emergency events (Cal Poly 2018).

Table 16 Wildfire Hazard Severity Zones and Percent of No Vehicle Households per Block Group Percent of No Vehicle Households Number of Block Groups 0-5% 17
5-10% 8
10-15% 3
15-20% 4
Source: Fehr and Peers 2021
The other portion of the City with a noticeably high percentage of households without access to vehicles is the downtown area near Marsh Street and High Street, likely to due to the high-density housing and closer proximity to goods and services in these areas. It is important to note here that areas of the City with lower vehicle access do not necessarily mean increased vulnerability to emergency evacuation events but that more coordination is needed in these areas including Car Less Collection Points during evacuation scenarios for residents without vehicles. The City has identified Car Less Collection Points in this area including one in Meadow Park and one in the San Luis Obispo Mission Plaza. As the City continues to implement its CAP, which includes efforts to reduce single-occupancy vehicle trips and the needs for personal vehicle ownership, coordination and planning for evacuation scenarios for these areas of the City will need careful consideration.

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Note: No vehicle Households: Low = 0-5%, High = 5-21%; Source: Fehr and Peers 2021 Figure 23 Wildfire Hazard S
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As shown in Figure 24, areas with a higher share of older adults and youth include areas of moderate to very high FHSZs. The Sinsheimer Neighborhood (Census Tract 110.01) is particularly vulnerable to wildfire impacts as the neighborhood is adjacent to moderate to very high FHSZs, and has the highest percentage of elderly (20 percent) and youth (7 percent) populations in the city, as well as the second highest percentage of disabled populations (12 percent). The Laguna Lake and Los Osos Valley Road (Census Tract 113) is also particularly vulnerable to wildfire risk, with a high percentage of elderly residents (14 percent), disabled (10 percent) populations, and households experiencing linguistic isolation (8 percent), which may present issues during emergency evacuation events.

Wildfire Smoke
While the City is at risk from the impacts of wildfires, the City and its residents are also susceptible to impacts of smoke from wildfires in the coastal mountain ranges of central California and the Los Padres National Forest to the east of the City. Wildfire smoke in the surrounding region and, due to wind patterns, wildfires along the central coast in general, can greatly reduce air quality in the City and cause public health impacts as well as impacts to tourism and normal community functions. Community public health factors that can increase the impacts of wildfire smoke include the prevalence of asthma in children and adults; chronic obstructive pulmonary disease; hypertension; diabetes; obesity; percent of population 65 years of age and older; and indicators of socioeconomic status, including poverty, income, and unemployment. In addition to health risks from smoke inhalation, older adults may also be less mobile and experience challenges with evacuation. Disadvantaged communities are vulnerable to wildfire impacts because they score high on many of the public health factors and socioeconomic indicators described above. As shown in Figure 25 and in Figure 26, disadvantaged communities and low-income areas in the City are also located in high and very high fire hazard severity zones. This overlap may present challenges for low-income residents, who may not have resources to recover from wildfire events when they do occur or resources for increasing their preparedness for wildfire events (e.g., defensible space improvements, emergency resources). Figure 27 includes the high and very high fire hazard severity zones as well as the location and density of homeless encampments in the City. The co-location of homeless populations and areas with higher wildfire risk places these populations at higher risk to wildfire impacts when they do occur as well as higher risk of wildfire occurrence due to ignitions at these encampments.

Exposure to wildfire smoke, particularly exposure to vulnerable populations, can result in worsening of respiratory symptoms, increased rates of cardiorespiratory emergency visits, hospitalizations, and even death (Rappold et al. 2017). In the summer of 2020, wildfire smoke alerts were issued for the County due to poor air quality caused by the Dolan Fire near Big Sur (The Tribune 2020a). Wildfire smoke can also have impacts on the labor market and the economy in general, with air quality affecting the ability of outdoor workers to perform their work, industries that operate partially or entirely outdoor (e.g., wineries, recreation activities, sporting events), and the tourism industry (Borgschulte et al. 2019).

Tourism and Economic Impacts
Wildfires can damage not only buildings and infrastructure, but also the natural environment, including portions of the City and the areas in the County that serve as regional recreation and tourism opportunities. Hiking, camping, biking, wine tasting, fairs, music festivals, and other popular tourism and recreation activities can be disrupted by wildfires both during and in post-wildfire periods. In addition to reducing the abilities of individuals to partake in these activities, the financial impacts caused by wildfires on these industries and the economy at large can be devastating. Major wildfires often result in damage to transportation infrastructure and/or closure of roadways. Combined with potential impacts of wildfire smoke from surrounding areas, wildfires may significantly reduce the overall desirability of the City and County for visitors coming from other areas in the state as well as locations outside the st DRAFT
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Sources: Data received from SLOCOG in 2021 and data downloaded from CAL FIRE in 2008 & 2020, City of San Luis Obispo in 2020 and County of San Luis Obispo in 2020
Figure 24 Share of Older Adults and Youth and Fire Hazard Severity Zone in the DRAFT
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Sources: Data received from SLOCOG in 2021 and data downloaded from CAL FIRE in 2008 & 2020, City of San Luis Obispo in 2020 and County of San Luis Obispo in 2020
Figure 25 SLOCOG Identified Disadvantaged Communities and Fire Hazard Severity Zone in DRAFT
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Sources: Data received from SLOCOG in 2021 and data downloaded from CAL FIRE in 2008 & 2020, City of San Luis Obispo in 2020 and County of San Luis Obispo in 2020
Figure 26 Low
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Sources: Data received from SLOCOG in 2021 and data downloaded from CAL FIRE in 2008 & 2020, City of San Luis Obispo in 2020, 2021 and County of San Luis Obispo in 2020
Figure 27 Homeless Encampments and Fire Hazard Severity DRAFT
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Public Safety Power Shutoffs
Beginning in 2019, electrical utilities in the state began to administer pre-emptive power shutoffs known as Public Safety Power Shutoffs (PSPSs) to portions of the electricity grid that were experiencing increased risk of wildfire due to specific weather conditions. PG&E, which operates the transmission lines in and around the City and has administered several PSPS events throughout their service territory, use specific criteria when determining a PSPS events (PG&E 2020). These include:
 Low humidity levels (generally 20 percent or below)
 High wind forecasts (sustained winds above 25 miles per hour and wind gusts above 45 miles per hour)  Low moisture content of live vegetation
 Red Flag Warnings declared by the National Weather Service  Real-time ground observations from the PG&E Wildfire Safety Operations Center PG&E has projected that future occurrence of these events will occur across their service territory more frequently with most events occurring in the late summer and fall months during the historic fire season as shown in Figure 28.

Additionally, to help identify areas in the state with increased risk from wildfires caused by utility infrastructure, the California Public Utilities Commission has developed a Fire Threat Map. As shown below in Figure 29, while future frequency of PSPS events in the City is unknown, the City is in a location adjacent to “Elevated” and “Extreme” Fire Threat Hazard Zones and transmission lines that help provide power to the City transverse both Elevated and Extreme Fire Threat Hazard Zones, making the City more likely to experience PSPS events in the future as the climate conditions that lead to these events become more common due to climate change.

Projected PSPS events per month based on weather data collected over the last 30 years.

Source: PG&E 2020
Figure 28 Potential PG&E PSPS Events per Year by Month
Electricity to the City is provided by PG via a 115 kilovolt (kV) transmission line and three 21kV distribution lines from the Morro Bay area. Currently, there are no redundant or backup facilities or resources for continuous electrical service if a utility disruption were to occur to these facilities. Through coordination with PG&E, the City will be notified during planned shut offs
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The CPUC Fire-Threat Map depicts areas with increased risk from wildfires caused by transmission lines and where enhanced fire safety regulations have been enacted for utilities by the CPUC.

Source: CPUC 2021
Figure 29 California Public Utility Commission Fire Threat Map Although residents in the City may not live or work in a high fire-threat area, their power may also be shut off if their neighborhood or home relies upon a line that passes through an area experiencing extreme fire danger conditions.

During PSPS events, businesses and homes in the City lose power temporarily which can result in a variety of shortterm impacts on the community including access to pharmacies, grocery stores, and other essential businesses for residents; secondary economic impacts on these businesses; loss of productivity for employees and employers; and loss of products for businesses requiring refrigeration such as grocery stores and restaurants. PSPS events may also affect telecommunication services such as cell towers and inhibit the ability to communicate information to residents during emergency events. However, in January 2020, SB 431 was adopted, which requires telecommunications service providers to develop backup power supplies to maintain minimum service for at least 72 hours during power outages. The bill also requires that during a utility deisruption, telecommunications servicee providers must provide communication services to emergency communication dispatch centers, emergency operations centers, federallyqualified health centers, fire stations, general acute care hospitals, police stations, and rural health clinics.

Considering that PSPS events are projected to occur in the late summer and fall months which are typically the warmest months in the City, the compounded effect of power loss during heat wave events could have considerable public health impacts leaving residents and businesses without power and air conditioning during heat wave periods.

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These impacts would be even more severe for populations who are at increased risk from heat-related illnesses including persons over the age of 65, infants and children, individuals with chronic health conditions (e.g., cardiovascular disease, asthma), low-income populations, athletes, and outdoor workers (CDC 2019). Residents who require at home supplemental oxygen, refrigerated medications, and other medical equipment that requires electricity are also at increased risk during PSPS events. Additionally, a loss of power can disrupt heating, ventilation, and air conditioning (HVAC) systems in homes and business, which are critical for maintaining indoor air quality. The combination of PSPS events occurring during periods of poor air quality caused by wildfire smoke can lead to poor indoor air quality and result in increased public health impacts.

Aside from the power supply related impacts of PSPS events, recent research has shown that PSPS events likely result in a ‘looming threat’ that can be linked to unintended poor mental health outcomes compounded by selfreported trauma lingering from previous wildfire experiences. Specific concerns expressed by individuals affected by PSPS events in 2019 included, rotting food in refrigerators, people with medical needs being unable to access needed electricity, in addition to personal concerns about individuals’ ability to conduct their normal daily activities. Other concerns included worries about how the PSPS events affected their ability to go to work or school, having to personally care or find childcare for children who were out of school due to the PSPS, and being unable to use air conditioning or a fan when needed. Regardless of actual impacts, the persistent “looming threat” of PSPS events for residents was a clear concern that led to worse mental health outcomes for some (Wong-Parodi 2020).

Local Impacts from Regional Wildfires
As shown in Figure 120, climate change is projected to increase the frequency and severity of wildfires not only in and near the City but at the County and regional level as well. Wildfires that occur at other locations in the County can have secondary impacts on the City as well including short-term impacts from route closures or delays, regional wildfire smoke impacts as discussed above, and economic impacts for employees who work in affected areas.

Wildfires that occur in the County or in the larger central coast region can also result in temporary or permanent wildfire refugees who need to relocate due to property loss or damage and may relocate in the city. This influx of new residents can place increased pressure on local resources and infrastructure as well as exacerbate housing supply and affordability issues that already exist (National Academies of Sciences, Engineering, and Medicine 2020).

Community Wildfire and Wildfire Smoke Concerns
As part of the community priorities survey, when asked about their concern for wildfires and wildfire smoke, as shown in Figure 30, 94 percent of participants indicated “Somewhat” or “Very” concerned. When asked about whether they have been personally affected by either event, 64 percent of respondents indicated “Somewhat” or “Very” for wildfires and 92 percent of respondents indicated “Somewhat” or “Very” for wildfire smoke. Additionally, wildfire smoke was of paramount concern for individuals within the lowest income group (i.e., 84 percent). Renters and individuals between the ages of 18 and 24 expressed the highest level of concern for wildfire and wildfire smoke.

Individuals who identify as White or Caucasian express a slightly higher level of concern both wildfire and wildfire smoke than individuals who identify as all other Races/Ethnicities.

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Sources: Resilient SLO Community Priorities Survey
Figure 30 City Resident’s Wildfire and Wildfire Smoke Concern and Impact Key Findings and Policy Considerations
 Wildfire events in the VHFHSZ near the Irish Hills Natural Reserve could potentially have immediate impacts to some residential areas on Royal Way, Sterling Lane and Isabella Way. Additionally, areas in the northeast of the City south of US 101 along San Luis Road are at risk from wildfire impacts and could potentially compromise evacuation management when wildfires do occur in this area.  The City serves as regional employment center, regional destination for tourism, and home to a university (Cal Poly) with approximately 20,000 students. These factors create an environment in which the City experiences a large influx of daily visitors to the City with a daytime population is estimated to be 90,000 (City of San Luis Obispo 2021c). If a wildfire event was to occur in or near the City during daytime hours, evacuation management would be particularly difficult and pose additional challenges due to this large influx of daily visitors. Additionally, because US 101 serves the main commuter corridor for locations north and south, wildfire events that occur along this route causing route closures (e.g., Cuesta Grade) can disproportionately impact employers and employees in the City.
 While the majority of the City is not at high risk from direct wildfire impacts, regional PSPS events have the potential to result in secondary impacts. Specifically, PSPS events occurring during heat wave events could have considerable public health impacts, leaving residents and businesses without power and air conditioning and further threaten residents who are medically-reliant on electricity for supplemental oxygen and refrigeration.  The confluence of PSPS, bad air quality, wildfire threat, and high heat days underscores the importance of homes and businesses as places of potential refuge.
 The Sinsheimer Neighborhood (Census Tract 110.01) and the Laguna Lake and Los Osos Valley Road (Census Tract 113) areas are particularly vulnerable to wildfire impacts as these areas of the City are located near moderate to very high FHSZs and include higher percentages of elderly (20 percent) and youth (7 percent) populations. Additionally, these areas have a high percentage of households experiencing linguistic isolation (8 percent) which may present issues during emergency evacuation events. 5%
16%
79%
6%
20%
74%
35%
43%
21%
7%
39%
53%
0%
20%
40%
60%
80%
100%
Not at all Somewhat Very
Percent of Respondents
Level of Concern

WILDFIRE SMOKE & WILDFIRES
Which of the following climate change impacts are you concerned about [Wildfire]? Which of the following climate change impacts are you concerned about [Wildfire Smoke]? Which of these hazards have you been personally affected by in the past 1-3 years in the City of San Luis Obispo [Wildfire]?
Which of these hazards have you been personally affected by in the past 1-3 years in the City of San Luis Obispo [Wildfire Smoke]?
Total Responses = 328
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 Exposure to wildfire smoke, particularly exposure to vulnerable populations, can result in worsening of respiratory symptoms, increased rates of cardiorespiratory emergency visits, hospitalizations, and even death (Rappold et al. 2017). Wildfires can damage not only buildings and infrastructure, but also the natural environment, including portions of the City and the areas in the County that serve as regional recreation and tourism destinations.

Accordingly, wildfire smoke has the potential to harm the local economy by reducing tourism and its related industries.

2.5.3 Adaptive Capacity for Wildfire Impacts
As discussed in the previous section, portions of the City are at considerable risk from wildfire impacts as well secondary impacts to residents and businesses from wildfire smoke and PSPS events. However, wildfire risk is not a new hazard for the City and partner agencies have taken considerable steps to mitigate wildfire impacts when they do occur.

WILDFIRE RISK REDUCTION AND PREPAREDNESS
Wildfire risk is addressed in the City’s Annex G of the County’s Multi-Jurisdictional Hazard Mitigation Plan and includes a set of mitigation goals, objectives, and actions specifically focused on addressing wildfire risk. Additionally, the City of San Luis Obispo adopted the Community Wildfire Protection Plan in 2019 which focuses on fire protection planning in the City, working on minimizing wildfire risk to areas in and around the City limits. Section IV of the plan includes a comprehensive set of goals and policies with implementation timelines to reduce wildfire risk in the community. The strategy categories include:
 Education policies to prepare response organizations, communities, the public, and policy makers regarding appropriate community actions and interactions to reduce the unwanted impacts of fires in the wildland urban interface.
 Fuels Management policies to mitigate the unwanted impacts of wildfires on communities through proper vegetation management techniques that reduce hazardous fuels and the resulting wildfire intensity.  Planning policies to help mitigate wildfire impacts in the City through community planning (including new resilient community design, retrofitting existing communities, and community recovery from the impact of fire), response planning, evacuation planning, and preparedness planning for responders, communities, individuals, animals, and livestock.
 Emergency Response policies to mitigate wildfire impacts on life, property, and resources by having an efficient and effective response that includes properly trained personnel, appropriate equipment, and a community prepared to take appropriate action or evacuate.
 Ignition Resistance policies mitigate structural ignitions from radiant heat, flame contact, or embers from wildland urban interface fires.

In regard to helping prepare the general public for wildfire hazards, the City’s Fire Department has provided a comprehensive set of videos and resources through the Prepare SLO information campaign to inform residents and businesses on how to reduce risk from wildfires, prepare for wildfire events when they do occur, as well as how to recover from wildfire impacts. In addition to the City’s wildfire preparedness efforts, the County’s Office of Emergency Services (OES) works to help coordinate emergency response efforts between the County, the City, and relevant partner agencies including CAL FIRE during emergency events. The County OES also manages the Ready SLO website which provides a comprehensive set of resources to help County residents prepare for hazard events including information needed in preparing for hazards, key hazard resources such as evacuation routes, and the County’s emergency alert system
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which residents can sign up for to receive notifications and alerts during emergency events.

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ENERGY RESILIENCE
In recent years, PG&E has also taken considerable steps to reduce the severity of impacts of PSPS events when they do occur (PG&E 2020). These steps include:
 electricity grid upgrades to break the grid into smaller parts to limit the size of outages when they do occur;  preparing microgrids in areas most likely to experience PSPS events to safely provide electricity to areas that are safe to keep energized during PSPS events;
 supporting communities and customers to develop their own multi-customer or community-level microgrids;  implementing system hardening improvements including installing stronger, fire resistant poles, covered lines and conducting targeted undergrounding in areas of high wildfire risk; and  using better weather monitoring technology and installing new weather stations to more precisely forecast the weather that could lead to PSPS events.

The City also benefits from the efforts undertaken by the San Luis Obispo County Fire Safe Council (Fire Safe Council). The Fire Safe Council is a diverse group of local and regional stakeholder that work to create fire safe communities in the County. The group provides educational resources to residents and businesses to reduce wildfire risk at the neighborhood and property level as well as help manage and fund wildfire fuel reduction projects throughout the County.

Central Coast Community Energy (3CE) is a Community Choice Energy agency established by local communities to source clean and renewable electricity for Monterey, San Benito and Santa Cruz counties , and parts of Santa Barbara and San Luis Obispo counties (including the City of San Luis Obispo). 3CE has begun to implement Resiliency Programs to help increase energy resilience for their customers. Most notably, 3CE has allocated $25 million to create the Uninterruptible Power Supply (UPS) Fund to accelerate and help finance the adoption of reliable backup power for public and private entities operating critical facilities, helping to ensure continuity of service and operations during PSPS events. 3CE is also working to develop a Residential Resiliency Incentive Program 2021 to help residential customers increase energy resilience through reliable backup power systems.

UTILITY DISRUPTION EMERGENCY OPERATIONS
Annex I of the City’s Comprehensive Disaster Leadership Plan focuses specifically on procedures to ensure a continuity of operations during a Utility Disruption event affecting portions or all of the City. This document is in in part a response to the potential increase in PSPS events effecting the City as well as other climate related hazards that may affect utility services. The City of San Luis Obispo has adopted the Incident Command System, the Standard Emergency System, and the National Incident Management System as the emergency organization and the emergency management system for response to a Utility Disruption event impacting the City. The document includes a set of actions to be taken prior to a Utility Disruption when any notification of anticipated severe fire weather concerns are issued by PG&E as well as assigned roles for appropriate City departments during a Utility Disruption event. As stated in Annex I, the PG&E event notification will include:
 Estimated start time of a potential event
 Forecasted weather duration
 Estimated time range to full restoration
 Number of medical baseline customers in the potentially impacted area  Weather and Utility Disruption information can be found at www.pge.com/weather  Maps that include boundaries of the area subject to de-energization and affected circuits will be posted at www.pge.com/pspsportal
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Annex I also includes an initial assessment of what impacts may occur to various operations in the City during a Utility Disruption including disruptions to leadership operation, emergency reporting, evacuation, resource center information, animal sheltering, school disruptions, emergency services, City utilities (discussed below), transportation systems, communication systems, emergency public information communications, and security. The document also includes recovery actions to be taken once a Utility Disruption event has ended.

As a result of potential future PSPS, the City’s Utility Department has begun to develop precautionary measures to ensure the City is able to provide uninterrupted water service during short-duration power outages. The City’s 2020 UWMP includes discussion of efforts to prepare for power outages of up to seven days and to ensure water is provided to critical facilities including the City’s Emergency Operations Center, area hospitals, the SLO County Emergency Operations Center, the Cal Poly campus, and the SLO County airport. The City has a set of portable generators that are deployed as needed to various locations in the City’s water conveyance system during power outages. The City also has a set of permanent backup generators at key facilities including the City’s Water Treatment Plant, Whale Rock Reservoir, and other pump stations and lift stations to ensure uninterrupted water service is provided in power outage scenarios.

For these reasons, the adaptive capacity ranking for wildfire risk is medium.

2.5.4 Vulnerability Summary
As discussed above, climate change is projected to cause an increase in the size and frequency of wildfire events due to changes in average temperatures, extreme heat events, and long-term drought scenarios over the 21st century. While the City includes some areas that are a high risk from wildfire impacts, the majority of the City is at moderate risk from direct wildfire impacts. However, due to the regional characteristics of wildfire impacts the City is still vulnerable to secondary wildfire impacts including untended consequences of PSPS events as well as public health impacts from regional wildfires that generate wildfire smoke and poor air quality in the City. These changes will result in varying impacts on the City and its residents as discussed above. Based on the analysis of various impacts discussed in Section

3.3.2, the City’s potential impact scoring is High (3). Wildfire impacts that are unique to the City and should be given increased consideration during the adaptation strategy development process are discussed below.

Natural System Findings
 The increasing frequency of fire on chaparral landscapes have caused coastal sage shrubs and chaparral to shift to grasses, including exotic grasses. Some research has suggested that annual and some perennial grasses have the strongest effects on fire regimes and act as ecosystem transformers.  Wildfire impacts in riparian zones can reduce canopy cover, resulting in increased water temperatures in creeks and other shaded waterways, as well as increased sediment flux in stream beds and adjacent areas, affecting the food web of burned stream areas and increasing the density of algae in waterways.  Post-wildfire runoff and debris flows can be affected by several factors but are generally triggered by one of two processes: surface erosion caused by rainfall runoff, and landslides caused by rainfall seeping into the ground.

While it is uncertain the effect climate change will have on post-wildfire runoff and debris flow events, climate change is projected to result in higher intensity rainfall events as well as “whiplash events” with oscillations between extremely dry and extremely wet periods, potentially affecting post-wildfire hazards.

Built Environment Findings
 The risk of wildfire is dependent on a variety of factors not excluding biophysical factors that are affected by climate change including Resources (e.g., land use patterns, vegetation growth), Ignitions (e.g., lightning, accidental ignitions, arson), and Conditions (e.g., precipitation, wind, seasonal variation). Approximately 95 percent of wildfires in the state are caused by human ignition. However, climate change is projected to increase the frequency and severity of wildfires, when they do occur (Mann et al. 2016).  The combination of dry climate conditions and the seasonal high autumn winds in California can increase the risk of trees or branches falling on transmission lines and causing power outages or wildfires. While these events have occurred historically, the effect of climate change on biophysical features that increase the risk of DRAFT

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wildfires (e.g., precipitation, wind, seasonal variation) will increase the frequency and severity of wildfires from transmission line ignitions.
 There was limited development within the WUI in the city for the period of 2001 – 2016, with a few prominent exceptions including the Madonna Area and the Margarita Area to the east of South Higuera Street. However, buildings outside of the WUI are also at risk from ignition due to the spread of firebrands (or embers) that can initiate new spot fires.
 Wildfire events in the VHFHSZ near the Irish Hills Natural Reserve could potentially have immediate impacts to some residential areas on Royal Way, Sterling Lane and Isabella Way. Additionally, areas in the northeast of the City south of US 101 along San Luis Road are at risk from wildfire impacts and could potentially compromise evacuation management when wildfires do occur in this area.

Community Resilience Findings
 The City serves as regional employment center, regional destination for tourism, and home to a university (Cal Poly) with approximately 20,000 students. These factors create an environment in which the City experiences a large influx of daily visitors to the City. If and when a wildfire event was to occur in or near the City during daytime hours, evacuation management would be particularly difficult and pose additional challenges due to this large influx of daily visitors. Additionally, because US 101 serves the main commuter corridor for locations north and south, wildfire events that occur along this route causing route closures (e.g., Cuesta Grade) can have a disproportionate impact on employers and employees in the City.  While the majority of the City is not at high risk from direct wildfire impacts, regional PSPS events that affect the City will result in a set of potential secondary impacts. Specifically, PSPS events occurring during heat wave events could have considerable public health impacts, leaving residents and businesses without power and air conditioning and further threaten residents who are medically-reliant on electricity for supplemental oxygen and refrigeration.  The confluence of PSPS, bad air quality, wildfire threat, and high heat days underscores the importance of homes and businesses as places of potential refuge.
 The Sinsheimer Neighborhood (Census Tract 110.01) and the Laguna Lake and Los Osos Valley Road (Census Tract 113) are particularly vulnerable to wildfire impacts as these areas of the City are located near moderate to very high FHSZs and include the higher percentages of elderly (20 percent) and youth (7 percent) populations.

Additionally, these areas have a high percentage of households experiencing linguistic isolation (8 percent) which may present issues during emergency evacuation events.
 Exposure to wildfire smoke, particularly exposure to vulnerable populations, can result in worsening of respiratory symptoms, increased rates of cardiorespiratory emergency visits, hospitalizations, and even death (Rappold et al. 2017). Wildfires can damage not only buildings and infrastructure, but also the natural environment, including portions of the City and the areas in the County that serve as regional recreation and tourism destinations.

Accordingly, wildfire smoke has the potential to harm the local economy by reducing tourism and its related industries.

Wildfire Vulnerability Score
Adaptive Capacity: Medium (2)
Potential Impact: High (3)
Vulnerability Score: 4

2.6 PRECIPITATION AND FLOODING ANALYSIS
This section discusses future increases in annual precipitation and increases in the frequency and severity of large storm events in watersheds affecting the City. The section analyzes how these changes are likely to impact the City DRAFT

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and its population as well as highlights what capacity the City and partner agencies already have in place to address these future impacts.

2.6.1 Future Exposure to Changes in Precipitation and Flooding According to Cal-Adapt, the historic average annual precipitation in the City is 21.2 inches. As shown in Table 17, the average annual precipitation in the County is projected increase to 22.6 inches in the near-term and 22.6 inches in the midterm under the high emissions scenario. Average annual precipitation is projected to be 21.6 inches under the medium emissions scenario and 25.2 inches under the high emissions scenario in the late century (CEC 2021a).

Although the City is anticipated to experience only moderate increases in annual precipitation, research indicates that the majority of the increase in annual rainfallis anticipated to occur during large storm events, which are projected to increase in size and frequency in the future.

Table 17 Changes in Average Annual Precipitation in City of San Luis Obispo Average Annual Precipitation Historic Average Annual
Precipitation (1961-1990)
Near-Term
(2021-2050)
Midterm
(2035-2064)
Late-Century (2070-2099)
Low Emissions High Emissions
Average Annual Precipitation (inches) 21.2 22.6 22.6 21.6 25.2 Notes: RCP = Representative Concentration Pathway.

Source: CEC 2019a

CLIMATE-INFORMED FLOOD RISK MODELING
As part of the development of the vulnerability assessment, a climate-informed flood risk modeling exercise was conducted to understand how changes in precipitation caused by climate change could affect the frequency and severity of large storm events (e.g., 100-year storm event) and how these changes would affect the flow of water through the City’s existing flood plains. The following section discusses the process used to develop this modeling and a summary of the modeling results.

Flooding Characteristics
Two interchangeable, technical terms that characterize flood frequency are used throughout the section and are defined as follows:
 Recurrence Intervals: A common way to describe floods is by stating their recurrence intervals, which refer to how often, on average, a given flood may occur. A 100-year event, for example, is described as an event that may occur about once in every 100 years, on average. However, this terminology can be misleading because flood events are statistical occurrences, and events may occur more frequently than their recurrence interval suggests.  Exceedance Probability: The exceedance probability of a given flood event is the percent chance that a larger flood will occur in any given year, and it is calculated by dividing the number 1 by the recurrence interval. Thus, the “100-year event” becomes the “1-percent exceedance event,” or a flow rate that has a 1-percent chance in any given year of being equaled or surpassed by a larger flow rate. This representation, although interchangeable with the recurrence interval, provides a more helpful way to think about flood risk.

There are several overall mechanisms by which flooding can occur:
 dam inundation flooding, in which impounded water is released because of dam breaching;  localized flooding, which occurs when intense rainfall overwhelms the capacity of local drainage infrastructure; causing the ponding of water; and
 riverine flooding, which occurs when channels (i.e., the relatively deep, narrow sections of creeks and rivers) cannot contain the flow volume moving through them, causing water to spill out into the overbank areas (i.e., the relatively wide, flat regions on one or both sides of the channel, also called “floodplains”).

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According to the Annex G of the County’s HMP, the City is not at risk of dam inundation flooding, as there are no major reservoirs within the watershed, and localized flooding is considered a minimal risk. The highest flooding concern for the City is riverine flooding, which may include “flash” flood risks (San Luis Obispo County 2019b).

Floods occur when the amount of water within the creek channels exceeds the channel capacity, causing water to spill over the banks and into the surrounding land. In these flat, flood-prone areas beyond the channel, called floodplains, slow moving or stagnant water that escapes the channel may remain until water levels within the channels recede or the areas are drained by infrastructure, percolation, or evapotranspiration. Naturally, these floodplain areas would have been flooded every few years, but as the City developed onto portions of the floodplains of the creeks within the San Luis Obispo Creek watershed, channel incision and flood protection measures constrained flows to the creeks. During periods of intense rainfall, however, the watershed outflow, including urban runoff, can exceed the capacity of the channels. Under existing conditions, different creeks within the watershed may experience flooding every 10-25 years (Questa Engineering Corporation 2003). The goal of the flood impacts assessment was to determine how the current level of flood risk is projected to vary as a result of climate change.

Flood Risk Modeling Methodology
To understand how flood risk for the City is likely to change in the future due to climate change, modeling software was used to assess projected changes in rainfall and analyze how these changes would affect flood inundation. The first step in determining the change in flood risk involves conducting long-term hydrologic modeling of the San Luis Obispo Creek watershed with historic and future daily precipitation data to understand changes in stream flow. This type of model simulates the ability of the watershed to store and release water over time through various processes, and by determining how quickly water is passed through the system, the model can be used to understand how flow within creek channels will respond to rainfall. It is based on physical watershed attributes such as slope, drainage area, land cover, geology, channel geometry, and initial soil moisture conditions, which control how much of the precipitation will be converted to streamflow versus being held within the watershed or lost to the atmosphere. For this analysis, a hydrologic model was developed using the Soil and Water Assessment Tool platform (SWAT), which was calibrated using historical gridded precipitation data (Livneh et al. 2015) and United State Geological Survey daily flow records from 1978 – 1985 for the Lower SLO Creek gage.

The SWAT hydrologic model was then used to simulate both historic (1970 – 1999) and future (2070-2099) daily precipitation records from 10 General Circulation Models recommended by the California Department of Water Resources for this type of modeling. These atmospheric models simulate global patterns for temperature, precipitation, and other atmospheric data over long periods of time. For the purpose of this assessment, the high emissions scenario over the long-term period (2070-2099) was used for this exercise. The 30-year future daily precipitation records were then simulated in the SWAT model, in addition to historic precipitation records (1970 – 1999). Using the average of the 10 future simulations, flow frequency statistics (England et al. 2019) were computed to determine how different flood events (e.g., the 100-year event) are projected to vary as a result of climate change.

To assess flood impacts on the City’s existing floodplains from changes in precipitation, further hydraulic modeling was needed. Hydraulic modeling is a process that uses the physical representation of a river network, including channel geometries, land slopes, surface characteristics, and structural information, to understand how quickly water moves through different channel reaches, how deep it is, and where overbank flooding may occur. For example, water flowing across a smooth concrete surface will move much faster than water passing through vegetation or through gravelly waterways. From a hydraulics perspective, the vegetation is said to have higher ‘roughness’ than the concrete, and empirical values are available to indicate this concept of roughness within hydraulic models. Likewise, channels that have steeper slopes or greater cross-sectional areas will be able to move water more quickly than those with gentler slopes or smaller areas. Bridges, culverts, and other structures can also greatly affect flow. As illustrated in Figure 31, a suite of hydraulic models using the HEC-RAS platform was developed for the Waterway Management Plan (Questa Engineering Corporation 2003), spanning San Luis Obispo Creek from Reservoir Canyon to Avila Beach, Prefumo Creek from Madonna Road to the San Luis Obispo Creek confluence, East Fork San Luis Obispo Creek and portions of its tributaries, and portions of Stenner, Brizziolari, and Old Garden Creeks. These models were adapted to the current study by scaling the peak flows used in the WMP by the factors from Table 18. The 500-year event was not studied for the Waterway Manag
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Management Agency (FEMA) flood insurance studies (FEMA 1978) for all examined creeks except for East Fork San Luis Obispo Creek.

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Source: cbec eco-engineering 2021
Figure 31 HEC
DRAFT -RAS Hydraulic Model Extent

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Table 18 Climate-induced Changes in Peak Stream Flow for the San Luis Obispo Creek Watershed Flood Event
(Return Interval)
Percent chance of flood
occurring in any given year
Percent increase in peak stream flow
90th Percentile 50th Percentile (median) 10th Percentile 500-Year 0.2% 122% 38% 4%
200-Year 0.5% 116% 38% 4%
100-Year 1% 110% 38% 4%
50-Year 2% 103% 37% 4%
20-Year 5% 93% 35% 3%
10-Year 10% 84% 33% 3%
5-Year 20% 73% 29% 3%
2-Year 50% 51% 28% 8%
1-Year 99% 64% 17% -31%
Source: cbec eco engineering 2021. The late century (2070-2099), RCP 8.5 scenario was used to determine flood impacts.

For each flood event, historic flow rates (using WMP hydrology for 10-year, 50-year, and 100-year and FEMA [1978] hydrology for the 500-year excluding East Fork of San Luis Obispo Creek) and scaled future peak flow rates based on projections from Table 18 were simulated in the HEC-RAS models representing channel conditions in the early 2000’s.

Flood inundation maps were then generated by extending modeled water surface elevations over a digital elevation model of the watershed (Woolpert 2019) to determine inundated acreage and depth of water on floodplain areas (not including channels or Laguna Lake) that were physically connected to flood sources. The assessment was divided into 9 regions to understand how flood impacts varied throughout the City and outlying areas.

Modeling Results
The following section discusses the results of the climate-informed flood risk modeling exercise. Table 18 includes the modeling results for various size storm events in the San Luis Obispo Creek watershed for the long-term period (2070-2099) under a high emissions scenario.

As shown in Table 18, the 10th percentile results indicate an extremely dry scenario, which experiences decreases in flow for events with less than a 2-year recurrence interval, while the 90th percentile results represent an extremely wet future scenario and results in peak flows more than doubling for events that occur every 50 or more years. For flood events occurring more rarely than every 2-years, flows are expected to increase across all scenarios including the 10th percentile projection. Overall, the median projection represents the best available estimate at this time for the San Luis Obispo Creek watershed for how peak flows are likely to change if global GHG emissions maintain the high emissions scenario trajectory for the long-term period.

The climate-induced increases in flood magnitude are due to increases in precipitation intensity. As the atmosphere warms, its ability to hold water vapor increases. While total annual precipitation in different parts of the state is projected to increase, decrease, or stay the same depending on the location, the trend of increasing rainfall within shorter periods of time (increasing intensity) is projected to occur broadly (OPR et al. 2018). In this way, even areas that may become drier and experience water scarcity as a result of climate change may also experience increased flood risk. Based on California’s location next to the Pacific Ocean, the state is exposed to the atmospheric river (AR) phenomenon, a narrow corridor of concentrated moisture in the atmosphere. California is subject to precipitation from an AR that transports water vapor from as far south as Hawaii to the state. The presence of the AR contributes to the frequency of “wet years” in the state, when there is an above-average number of AR storms and above-average annual precipitation. Projected peak stream flow increases are also greater for larger (less frequent) flood events than for smaller ones, as a result of the watershed’s diminishing ability to absorb increasingly high levels of rainfall. For example, following a long, dry summer, the land surface, soils, and vegetation will have a relatively high capacity to hold incoming rain and very little stream flow may be generated from a notable amount of rainfall. In the mid-winter months, after a series of precipitation events has passed through, the soils are relatively saturated and generate runoff more quickly. For very large precipitation events, the capacity of the watershed to absorb incoming rainfall can be quickly exceeded, causing large increases in stream DRAFT

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flow within the system. For the median scenario, peak flow rates are projected to increase from 17 percent to 38 percent for events that occur every year to every 500 years, on average, as show in Table 18.

While research indicates that the frequency of large storms events does increase in these wet years, the most severe flooding from ARs may not be in wet years (Swain et al. 2018). The largest flooding impacts are caused by persistent storm sequences on sub-seasonal timescales (i.e., short time periods, typically 2 weeks to 3 months), which bring a significant fraction of annual average precipitation over a brief period. These storms events are similar to the Great Flood events of 1861–1862, which caused widespread damage throughout northern California (Swain et al. 2016).

Based on current climate modeling, the frequency of these large storm sequences over short timeframes is projected to increase noticeably under the high emissions scenario. It is estimated that a storm similar in magnitude to the Great Flood event is more likely than not to occur at least once between 2018 and 2060 (Swain et al. 2018).

Although annual precipitation is anticipated to increase in the City and the larger central coast region, California’s climate oscillates between extremely dry and extremely wet periods with annual precipitation varying widely from year to year. Climate change is anticipated to exacerbate these seasonal extremes with dry periods becoming dryer and wet periods becoming wetter (OPR et al. 2018b:19). As a result, the frequency and severity of large storm events are anticipated to increase as well. These oscillations between extremely dry and extremely wet periods, which have occurred historically in the state, are anticipated to become more severe with rapid shifts from dry to wet periods known as “whiplash events” (Swain et al. 2016). As Swain et al. note in their research, the recent 2012–2016 drought followed by the 2016–2017 flood events throughout the state serve as a good example of the type of whiplash events that will occur more frequently over the next century. These types of events are estimated to increase by approximately 100 percent in southern California, with increases in frequency occurring largely after 2050 (Swain et al. 2016).

2.6.2 Precipitation and Flooding Sensitivities and Impact This section discusses the City’s existing sensitivities to increases in annual precipitation and flooding events, analyzing potential effects on the City including a discussion of general impacts as well as secondary impacts. This impact analysis focuses specifically on impacts to the City’s built environment and transportation network.

FLOODING AND NATURAL SYSTEMS
Future Flood Mapping Results
Based on hydraulic modeling discussed above, future floodplain maps were generated to understand how changes in precipitation for the 10- year, 50-year, and 100-year storms events would impact the City as shown in Figures 32 through 40. Additional modeling for the 10-year, 50-year, 100-year, and 500-year storms events is included in Appendix A. Figures 32 through 40 show the generated depth maps for historic and future (long-term high emissions [RCP 8.5] scenario) conditions for the 10-year (Q10) and 100-year (Q100 events within the San Luis Obispo Creek – Stenner Creek and San Luis Obispo Creek – Prefumo Creek confluence areas. These figures provide an illustration of the future extent of flood plains in the San Luis Obispo Creek watershed. However, there are limitations preventing these maps from being used for more detailed or more absolute flood extent delineations for historic and future conditions. One main limitation is the reliance upon hydraulic models that are almost two decades old and do not cover all areas of the City as well as an uncertain range of possibilities for future precipitation and future global emissions trends during the late-century period. However, the mapping exercise is useful for indicating the locations and extents of relative flood impacts that may reasonably be expected to occur due to climate change under the late-century high emissions scenario.

To further understand relative flood impacts, the hydraulic model domain was divided into nine analysis regions where changes in inundated area in acres and average depth on the floodplain (ft) were compared between historic and future conditions for each flood event, as shown in Tables 19 and 20. To determine these statistics for floodplain areas, the regions within the creek channels and Laguna Lake were removed from the analysis DRAFT
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Source: cbec eco engineering 2021
Figure 32 Flood Depth: Full Extent
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Figure 33 Flood Depth: SLO
DRAFT -Stenner - Q10 (Historic) Flood Depth - Q100 (Historic)

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Figure 34 Flood Depth: SLO
DRAFT -Stenner - Q10 (Future 2070-2099 – RCP 8.5)

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Source: cbec eco-engineering 2021
Figure 35 Flood Depth: SLO
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Source: cbec eco-engineering 2021
Figure 36 Flood Depth: SLO
DRAFT -Stenner - Q100 (Future 2070-2099 – RCP 8.5)

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Source: cbec eco-engineering 2021
Figure 37 Flood Depth: SLO
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Figure 38 Flood Depth: SLO
DRAFT -Prefumo - Q10 (Future 2070-2099 – RCP 8.5)

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Source: cbec eco-engineering 2021
Figure 39 Flood Depth: SLO
DRAFT -Prefumo - Q100 (Historic)

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Figure 40 Flood Depth: SLO
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Table 19 Change in Connected Floodplain Areas for 9 Analysis Regions from Historic to Future (median) Conditions.

Region Description
Connected floodplain area (acres)
Q10 Q50 Q100 Q500
Historic Future Change Historic Future Change Historic Future Change Historic Future Change SLO-1 SLO Cr. below East Fork 456.49 483.01 5.8% 501.64 546.1 8.9% 518.52 570 9.9% 639.41 696.2 8.9% SLO-2 SLO Cr. from Prefumo to East Fork 120.52 130.44 8.2% 135.11 151.6 12.2% 138.97 155.7 12.0% 165.46 179.8 8.7% SLO-3 SLO Cr. / Prefumo Cr. confluence area 49.91 94.57 89.5% 119.76 240.7 101.0% 151.44 256.4 69.3% 306.49 365.3 19.2% SLO-4 SLO Cr. from Stenner confluence to Prado Rd. 123.78 153.36 23.9% 163.81 227 38.6% 182.15 238.7 31.0% 271.45 296.3 9.1% SLO-5 SLO Cr. upstream of Stenner confluence 43.39 91.53 110.9% 93.98 145.1 54.4% 99.79 149.7 50.0% 195.61 218.1 11.5% STEN Stenner, Brizziolari, and Old Garden Cr. 43.72 63.4 45.0% 78.73 109.9 39.6% 98.77 129.7 31.3% 152.21 183.8 20.7% LGNA Laguna Lake area 203.84 226.38 11.1% 260.8 287.1 10.1% 275.39 304 10.4% 367.98 409.5 11.3% EFK-1 East Fork from SLO Cr. confluence to Buckley Rd. 105.86 124 17.1% 133.24 145.4 9.1% 143.3 154 7.5% - - - EFK-2 East Fork and tributaries upstream of Buckley Rd. 50.72 79.22 56.2% 93.19 120.3 29.1% 108.72 129.5 19.1% - - - Source: cbec eco-engineering 2021
Table 20 Change in Connected Floodplain Depths for 9 Analysis Regions from Historic to Future (median) Conditions.

Region Description
Average connected floodplain depth (ft)
Q10 Q50 Q100 Q500
Historic Future Change Historic Future Change Historic Future Change Historic Future Change SLO-1 SLO Cr. below East Fork 4.1 4.8 17.1% 5.3 6.4 20.8% 5.8 6.8 17.2% 8.3 9.8 18.1% SLO-2 SLO Cr. from Prefumo to East Fork 2.6 3.3 26.9% 3.8 4.8 26.3% 4.1 5.1 24.4% 6.1 7.6 24.6% SLO-3 SLO Cr. / Prefumo Cr. confluence area 2 2.2 10.0% 2.3 2.5 8.7% 2.4 2.7 12.5% 3.6 4.9 36.1% SLO-4
SLO Cr. from Stenner confluence to
Prado Rd. 1.4 1.7 21.4% 1.8 2.1 16.7% 1.9 2.2 15.8% 2.8 3.4 21.4% SLO-5 SLO Cr. upstream of Stenner confluence 1.7 2.1 23.5% 2.1 2.5 19.0% 2.2 2.6 18.2% 3.4 4.2 23.5% STEN Stenner, Brizziolari, and Old Garden Cr. 2 2.2 10.0% 2.3 2.7 17.4% 2.4 3 25.0% 3.5 4.3 22.9% LGNA Laguna Lake area 4.6 5 8.7% 5.1 5.4 5.9% 5.3 5.5 3.8% 6.1 6.4 4.9% EFK-1
East Fork from SLO Cr. confluence to
Buckley Rd. 4 4.1 2.5% 4.3 4.7 9.3% 4.6 4.8 4.3% - - -
EFK-2
East Fork and tributaries upstream of
Buckley Rd. 2.4 2.3 -4.2% 2.3 2.3 0.0% 2.3 2.4 4.3% - - - Source: cbec eco-engineering 2021
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Key Findings and Policy Considerations
 Although annual precipitation is anticipated to increase in the City and the larger central coast region, California’s climate oscillates between extremely dry and extremely wet periods with annual precipitation varying widely from year to year. These oscillations between extremely dry and extremely wet periods are anticipated to become more severe with rapid shifts from dry to wet periods known as “whiplash events” (Swain et al. 2016). These types of events are estimated to increase by approximately 100 percent in southern California, with increases in frequency occurring largely after 2050 (Swain et al. 2016).
 Based on California’s location next to the Pacific Ocean, the state is exposed to the atmospheric river (AR) phenomenon, a narrow corridor of concentrated moisture in the atmosphere. The presence of the AR contributes to the frequency of “wet years” in the state, when there is an above-average number of AR storms and aboveaverage annual precipitation. While research indicates that the frequency of large storms events does increase in these wet years, the most severe flooding from ARs may not be in wet years (Swain et al. 2018). The largest flooding impacts are caused by persistent storm sequences on sub-seasonal timescales (i.e., short time periods, typically 2 weeks to 3 months), which bring a significant fraction of annual average precipitation over a brief period. Based on current climate modeling, the frequency of these large storm sequences over short timeframes is projected to increase noticeably under a future high emissions scenario. It is estimated that a storm similar in magnitude to the Great Flood events is more likely than not to occur at least once between 2018 and 2060 (Swain et al. 2018).  For very large precipitation events, the capacity of the watershed to absorb incoming rainfall can be quickly exceeded, causing large increases in stream flow within the system. By as early as 2070 under a high future emissions scenario, peak flow rates in the San Luis Obispo Creek watershed are projected to increase, on average, from 17 percent to 38 percent depending on the size of the storm event. By this period, for the storm event with a 50 percent chance of occurring in any given year (2-year storm event), the median peak stream flow is projected to increase by 28 percent with a small likelihood (90th percentile) of stream flow increasing by 51 percent.  By as early as 2070 under a high future emissions scenario, for the 100-year event, dramatic increases are observed on Stenner and Old Garden Creeks upstream of the San Luis Obispo Creek confluence and within the downtown area. In both cases, flooding is exacerbated by the capacity of the existing infrastructure to manage historic flooding events. Similar, during the 100-year event, increases in flow within San Luis Obispo Creek increasingly cause flood waters to break out of the channel upstream of the culvert and flow along the Higuera and Marsh Street corridor towards the Stenner Creek confluence

FLOODING AND THE BUILT ENVIRONMENT
Key Flood Impact Areas
Areas with the greatest increases in connected floodplain inundation for the 10-year through 100-year events included SLO Creek upstream of the Stenner confluence (SLO-5, including parts of downtown SLO), the SLO Creek – Prefumo Creek confluence area (SLO-3, including SLO Creek from Prado Road to the Prefumo Creek confluence and Prefumo Creek below Madonna Road), East Fork and its tributaries upstream of Buckley Road (EFK2), and Stenner, Brizziolari, and Old Garden Creeks (STEN). In the modeling, these areas tended to have greater expanses of floodplain areas, such as the SLO Creek – Prefumo Creek confluence area, or limiting infrastructure, as is the case with the undercity culvert through downtown. Areas that were more confined by topography, such as SLO Creek below East Fork (SLO-1), experienced smaller increases in area, as shown in Table 19. Average connected floodplain depth, on the other hand, can be slightly more difficult to assess because it was calculated as the average of wet areas with greater than 0.1 ft of depth. Therefore, the average depth can decrease even if the inundated area increases with large areas of shallow depth flooding in a future scenario that are currently inundated under existing
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downtown were on the order of 18 to 23.5 percent across the range of flood events, with an increase in average floodplain depth for the 100-yr event of 0.4 ft increasing to 2.2 to 2.6 ft, as shown in Table 20.

Figures 32 through Figure 36 show inundation depth for the 10-year and 100-year events for the San Luis Obispo Creek – Stenner Creek confluence area, including a portion of downtown. For the 10-year event, increases in flooding along Old Garden Creek are apparent, along with portions of downtown and at the confluence of the two creeks (Figures 32 and 33). Some of the flooding within the downtown area from the 10-year event may be due to the model generally over-predicting flood levels (Questa Engineering Corporation 2003). For the 100-year event, dramatic increases are observed on Stenner and Old Garden Creeks upstream of the San Luis Obispo Creek confluence and within the downtown area. In both cases, flooding is exacerbated by the capacity of the existing infrastructure to manage historic flooding events. For Stenner Creek, the water level passing underneath Highway 101 reaches up to the bottom of the bridge and begins to exceed the flow capacity of the structure. Similarly, the undercity culvert within downtown has a capacity of about a 15-year event under historic conditions (Questa Engineering Corporation 2003). For larger events, such as the 100-year, increases in flow within San Luis Obispo Creek increasingly cause flood waters to break out of the channel upstream of the culvert and flow along the Higuera and Marsh Street corridor towards the Stenner Creek confluence, as shown in Figures 35 and 36.

Figures 37 through 39 show similar results for the San Luis Obispo – Prefumo Creek confluence area. Within these regions of the City, large expanses of relatively flat, low-lying land persist between and along the two creeks. Flood waters can spill into these areas by crossing Highway 101 near Madonna Road from San Luis Obispo Creek or by escaping the creek channels in the confluence area and causing backwater conditions for upstream reaches. The City undertakes regular maintenance activities within Prefumo Creek from Laguna Lake to Los Osos Valley Road to manage flood risk in this area. The southern end of the Los Osos Valley Road area north of Highway 101 is particularly vulnerable. For the 100-year event, large areas of agricultural land between Prefumo and San Luis Obispo Creeks may become inundated under future conditions, as shown in Figures 39 and 40.

Ultimately, changes in flood risk need to be understood using multiple metrics. The flood maps and summary tables of changes in inundated area and average depth are important for understanding how different levels of risk are present within different areas of the City. These varying levels of risk may be due to the topography of the landscape and channels, but they may also be affected by infrastructure. In either case, changes in flood risk do not necessarily vary in the same way as changes in stream flow, which in turn may not directly mirror changes in precipitation, reinforcing the importance of conducting hydrologic and hydraulic modeling. For the 100-year event, there was a 38 percent increase in stream flow for the median future scenario compared to historical conditions, as show in Table 19. However, this does not necessarily translate to flooding being 38 percent worse. The reach of San Luis Obispo Creek upstream of the Stenner Creek confluence and the San Luis Obispo – Prefumo Creek confluence areas experienced increases in inundated floodplain acreage of 50 and 69.3 percent, respectively, as shown in Table 19, while average floodplain depths increased from 2.2-2.4 ft to 2.6-2.7 ft, as shown in Table 20. Further, it is helpful to think about flood risk statistically. As shown in Table 19, the future 50-year event has similar levels of inundation to the historic 100-year event. This means that with a 37 percent increase in flow (from the historic 50-year event, Table 19), the level of inundation from an event that used to occur about once every 100-years would be experienced twice as frequently.

IMPACT ANALYSIS OF THE TRANSPORTATION SYSTEM
Using the climate-informed flood analysis discusses above, a high-level impact analysis on the City’s transportation system was conducted, focusing on the facilities identified through community feedback including impacts to the transit network, the City’s open space trails network, and the viability of the City’s roadway network and evacuation routes during emergency evacuation scenarios related to flooding. The analysis was conducted using the 10-year, 100-year, and 500-year flood mapping layers, assessing how these flood events would affect the City’s transportation system. Figure 41
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overlays the flood zones on the transportation network and is discussed below.

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Figure 41 City
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Transportation Assets Impacted by Flooding

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Roadways
The City’s roadway network is identified as local streets, arterials, freeway, and bicycle and pedestrian facilities, providing circulation within the City as well as roadway network connections to the other areas in the County. The extent of roadway network impacts on the City is dependent on the varying size of the storm events analyzed. Figure 41 illustrates those potential impacts adjacent to San Luis Obispo Creek along US 101, specifically at the Madonna Road interchange and the Los Osos Valley Road interchange during the 10-year,100-year, 500-year storm events. The greatest area of impact to local roads during these events would be areas just south of San Luis Obispo Creek through the downtown area with the farthest extent along Santa Barbara Street as far South as Leff Street occurring during the 100-year storm event. Moving away from the downtown area, flooding occurs to the east of the SLO Creek between US 101 and Higuera Street between the US 101 and Broad Street interchange and the US 101 and Madonna Road interchange. During the 100-year and 500-year storm events, flooding would likely occur along US 101 in the northbound lanes at the Prado Road on and off ramp. Flooding would also occur along Prado Road near San Luis Obispo Creek. The flood modeling analysis also identifies the Chorro Street undercrossing at US 101 would be impacted by the 10-year, 100-year, and 500-year floods. These same flood zones would also result in potential impacts between Foothill Boulevard and US 101 between Broad Street and State Route 1.

Transit
Alongside the roadway network, future flood impacts would also affect transit operations and assets. Extensive flooding has the potential to limit transit service, thus eliminating transport options for populations in the City dependent on transit. Table 21 illustrates the number of impacted transit stops and percent of stops in the total network that would be affected, categorized by each size storm event and transit provider. The rail network in the City would not be affected during the potential flood events. The exact location of the transit stops impacted by the 10-year, 100-year, and 500-year storm events are visualized in Figure 42.

Table 21 Transit Stops Impacted by Storm Event
Transit Agency Total Number
of Stops
10-year 100-year 500-year
SLO Transit 161 7 - 11 % 16 - 26 % 35 - 57%
San Luis Obispo Regional Transit Authority (RTA) 26 2- 8% 3 - 12% 6 – 23% Source: Fehr and Peers 2021
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Figure 42 Transit Assets Impacted by Flooding
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Recreation Trails and Existing Bicycle Transportation
Flood related impacts on the City’s bicycle and recreational trails network were similar to impacts on the roadway network. Bicycle infrastructure through the downtown area south of the San Luis Obispo creek are likely to be affected by future flood impacts. As shown in Figure 42, the following recreational trail are also likely to be impacted by flooding.  Bob Jones Trail
 Johnson Ranch
 Madonna Inn Bike Trail
 Laguna Lake Upper Loop Trail
The areas of highest concern are located in the downtown area South of the San Luis Obispo Creek, the Chorro Street undercrossing, and around the Los Osos Valley Road interchange at US 101. It is important to define transit options for the limited number of stops impacted by flooding during flood events. If applicable, mitigation and engineering can remedy the flooding sources, transit would likely be unimpacted. Alternatively, the use of bicycle transit to transport populations without adequate mobility resources should be considered for evacuation plans.

Key Findings and Policy Considerations
 From the results of the climate-informed flood modeling, areas with the greatest increases in connected floodplain inundation for the 10-year through 100-year events included SLO Creek upstream of the Stenner confluence (including parts of downtown SLO), the SLO Creek – Prefumo Creek confluence area, East Fork and its tributaries upstream of Buckley Road, and Stenner, Brizziolari, and Old Garden Creeks. In the modeling, these areas tended to have greater expanses of floodplain areas, such as the SLO Creek – Prefumo Creek confluence area, or limiting infrastructure, as is the case with the undercity culvert through downtown.  By as early as 2070 under a high future emissions scenario, for the 100-year event, dramatic increases are observed on Stenner and Old Garden Creeks upstream of the San Luis Obispo Creek confluence and within the downtown area. In both cases, flooding is exacerbated by the capacity of the existing infrastructure to manage historic flooding events. Similar, during the 100-year event, increases in flow within San Luis Obispo Creek increasingly cause flood waters to break out of the channel upstream of the culvert and flow along the Higuera and Marsh Street corridor towards the Stenner Creek confluence.  Near the San Luis Obispo – Prefumo Creek confluence area near Higuera Street and Madonna Road, large expanses of relatively flat, low-lying land persist between and along the two creeks. During larger storm events (50-year and 100-year storms), flood waters can spill into these areas by crossing Highway 101 near Madonna Road from San Luis Obispo Creek or by escaping the creek channels in the confluence area and causing backwater conditions for upstream reaches.
 The greatest area of impact to local roads during large storm events (100-year storm) would be areas just south of San Luis Obispo Creek through the downtown area with the farthest extent along Santa Barbara Street as far South as Leff Street. The Chorro Street undercrossing at US 101 would be impacted by the 10-year, 100-year, and 500-year floods.
 Extensive flooding from larger storm events also has the potential to limit transit service, thus eliminating transport options for populations in the City dependent on transit, with between 16 to 26 percent of SLO Transit stops being
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FLOODING AND COMMUNITY RESILIENCE
Evacuation Routes and Emergency Communications
As part of this analysis, an assessment of the underlying hazards and appropriate access to gateways (e.g., major ingress and egress points in and out of the City) and evacuation centers has been completed to facilitate the development of reliable accurate communication for emergency needs and evacuations.

With the projected increases in the frequency and severity wildfire events, and large storm events expected to occur due to climate change, new methods of administering evacuation information have been evolving. Iterative development and updating of the emergency preparedness plan are critical and should identify a communication plan for residents and visitors on how to evacuate in case of an emergency. To support the communication components of evacuation planning, a detailed analysis of access to City gateways and evacuation centers is provided below to assist in identifying areas where infrastructure improvements would benefit future evacuation planning.

Flood Impacts and Low-Vehicle Access
Using the US Census block group data, Figure 43 illustrates census blocks in the City with the percentage of occupied housing units without access to a vehicle. According to the Census data, in the City, approximately 8 percent of occupied housing units do not have access to at least one vehicle. However, the range for all the block groups within the City is 0 to 21.4 percent. Certain block groups have higher numbers of households without vehicles available, therefore specific consideration for services to access evacuation centers or assistance of these populations to leave the City during an emergency should be prepared. The City’s Car Less Collection Points layer is included and shows some correspondence to the census block groups with a higher portion of households without vehicles. These populations tend to primarily be located adjacent to US 101 and the San Luis Obispo Creek.

Gateway and Evacuation Center Access Assessment
This section includes a scenario level review of residential access to City gateways and evacuation centers from the centroids of census block groups for the City. This assessment is based on an evolving methodology created for evacuation studies consistent with Assembly Bill (AB) 747 and SB 99, which requires an assessment of residential evacuation routes during the City’s next Safety Element update. The analysis included here is not a comprehensive assessment of the City’s evacuation routes but provides supporting resources for an evacuation study consistent with AB 747 and SB 99.

This document is intended to provide an assessment of roadway access under the described flood scenarios but should not be considered a full evacuation plan. Additionally, flooding patterns are, to a certain degree, unpredictable as is individual behavior related to evacuation events. As such, this assessment is intended to provide the City with a broad “planning level” assessment of the access of the transportation system during flood events; it does not provide guarantees as to the adequacy of the transportation system nor can it guarantee that the findings are applicable to any or all situations.

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Source: Fehr and Peers 2021
Figure 43 Census Block
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Groups with No Vehicles per occupied housing unit

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Evacuation Route Analysis Methodology
This analysis was developed in ArcGIS using network analyst as a variation on an evacuation scenario tool including the centroid of census block groups, and the flood zone layers provided by the City. The analysis calculates the closest route by distance from the centroid of a block group to the gateway outside of the City or the evacuation center nearest the centroids. As it relates to this study, gateways are defined as major arterials and highways located at the City limit. The gateways used in this analysis include the following roads, US 101 Northbound and Southbound at the respective City limits, State Route (SR) 227 or Broad Street, Orcutt Road, South Higuera Street, SR 1, and Los Osos Valley Road. The gateways matched the evacuation routes the City designated and communicates through the fire evacuation plan (City of San Luis Obispo n.d.).

Census block groups are statistical divisions of census tracts, are generally defined to contain between 600 and 3,000 people. In this analysis, the centroids of these block groups were calculated and joined with specific demographic data, citing whether vehicles were available for occupied housing units. This was done to visualize an even distribution of population and access throughout the City. When required the centroid locations were adjusted to reflect street network connectivity. The block group centroids were used to begin the travel analysis to both City gateways and evacuation centers. Flood zone for the analysis is defined by FEMA as the area that will be inundated by the 100-year flood event and 500-year flood event as discussed previously on section 2.5.1. CBEC generated the 10-, 100-, and 500-year flood waters data used in our transportation models.

Evacuation Route Analysis Results
For this analysis, access to the City’s gateways and evacuations centers were assessed without any flooding as a baseline condition. Access to these locations was then analyzed for the 10-year, 100-year, 500-year flood events to identify transportation route and asset vulnerabilities under each of these events. The following figures represent a visual representation of the analysis for the defined year flood events discussed above.

As shown in Figures 44 through 49, access from census block group centroids to City gateways for the 10-year, 100- year, and 500-year flood events are relatively similar as the locations of flooding occur in generally the same location under various storm events. As shown, under each flood event some routes within the City’s street network are compromised, in which case, an alternative route is created to analyze route diversions as a result of flood impacts. In many cases, this may result in a longer distance to be travelled to access the gateway or evacuation center under different flood scenarios.

For all flooding events (i.e., 100-year and 500-year flood events), access to the Southern Gateway of US 101 is compromised due to potential flooding of US 101 and Los Osos Valley Road. However, all centroids under these scenarios are able to access at least one alternative City gateway, which means no portions of the City would be closed off due to roadway network flooding. The 100-year flood scenario shows impacted access to many neighborhoods throughout the City, resulting in one Block Group centroid being cut off to both a gateway and evacuation center. This is in the area North of US 101 and West of SR 1.

The 500-year flood scenario shows an inability of four census block group centroids to access either the City gateways or evacuation centers as they experience extensive flooding, isolating their ability to connect to a route.

These centroids are located within the 500-year flood layer, thus preventing a routed network to be completed. The depth of the flooding is available however further analysis identifying the height of the infrastructure would be required to understand the extent of actual access from DRAFT
neighborhoods to gateways and evacuation centers.

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Figure 44 Access from Census Block Group Centroid to City Gateways DRAFT

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Figure 45 Access from Census Block Group Centroid to City Evacuation Center DRAFT
s

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Figure 46 Access from Census Block Group Centroid to City Gateways with 100 Year Flood DRAFT

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Figure 47 Access from Census Block Group Centroid to City Evacuation Centers with 100 Year Flood DRAFT

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Figure 48 Access from Census Block Group Centroid to City Gateways with 500 Year Flood DRAFT

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Figure 49 Access from Census Block Group Centroid to City Evacuation Centers with 500 Year Flood DRAFT

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Table 22 shows the difference between the baseline conditions access and each flood scenario.

Table 22 Flood Year and Longest Distances to City Gateways and Evacuation Centers Destination Baseline – No flood 100 year* 500 year**
Gateways 3.5 miles 4 miles 4 miles
Evacuation Centers 3 miles 5 miles 5 miles
Note: * = Signifies 1 Block Group centroid was cut off from both gateways and evacuation centers. ** - Signifies 4 Block Group centroids were cut off from both gateways and evacuation centers.

Source: Fehr and Peers 2021
Flooding and Vulnerable Populations
Several populations within the City may experience disproportionate impacts from flooding due to social characteristics and environmental burdens. Disadvantaged communities are more likely to be located in flood prone areas, may be linguistically isolated and unable to interpret and respond to warning messages and evacuation notices, and have limited mobility. As shown in Figure 50, the disadvantaged communities in the central portion of the City are located within the 100- and 500-year flood zones.

Lack of vehicle access is another social factor that may lead to increased vulnerability to flood events. Using the US Census block group data, Figure 43 illustrates census blocks in the City with the percentage of occupied housing units without access to a vehicle. According to the Census data, in the City, approximately 8 percent of occupied housing units do not have access to at least one vehicle. However, the range for all the block groups within the City is 0 to 21.4 percent. Certain block groups have higher numbers of households without vehicles available, therefore specific consideration for services to access evacuation centers or assistance of these populations to leave the City during an emergency should be prepared. The City’s Car Less Collection Points layer is included and shows some correspondence to the census block groups with a higher portion of households without vehicles. These populations tend to primarily be located adjacent to US 101 and the San Luis Obispo Creek.

A key environmental burden is the presence of cleanup sites, which are sites monitored by the Department of Toxic Substances Control that are contaminated with harmful chemicals. Flooding could release hazardous and/or toxic materials if cleanup sites are inundated, exposing nearby communities to public health impacts. CalEnviroScreen 4.0 includes a cleanup sites indicator that considers the number and types of cleanup sites in or near each census tracts, as well as how close the sites are to where people may live. As shown in Figure 52, there are several cleanup sites located within the 100-year flood zone. There are also census tracts in the City within the City’s 100- and 500-year flood zones that score in the 70th percentile and higher for clean up site exposure, based on the weighted score of potential pollution exposure used in CalEnviroScreen. This means these census tracts have higher potential exposure than 70 percent of all census tracts in the State, indicating that there is a potential for residents in these areas to be exposed to contaminants in the event of a flood.

As show in Figure 50, the area West of South Higuera Street (Census Tract 115.01) is located almost entirely within the 100- and 500-year flood plain which is anticipated to expand in the future due to climate change. This area is particularly vulnerable with high percentage of elderly residents (17 percent) as well as a high percent of disabled residents (15 precent), presenting potential challenges during emergency evacuation events. Figure 51 includes areas in the City with low-income households (i.e., households earning 80 percent less of the County median income) as well as the 100- and 500-year flood plain. During larger flood events, these households are at a potential disadvantage during the post-disaster recovery period with less financial or other resources available for recovery efforts. Additionally, as show in Figure 53 there is significant overlap between the location of homeless encampments throughout the City and the location of the existing and future 100- and 500-year flood plains. Shelters and encampments built by unhoused individuals are often developed in or near flood plains, placing these populations at increased risk during flood events, particularly in areas with lower levels of access to transportation in emergency events. Increased heavy precipitation and flooding will disproportionately impact homeless populations because they occupy marginal areas, they are less able to transport themselves out of flood areas and they are more likely to suffer sequelae (i.e., exacerbation of existing health conditions) from such disasters.

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(Ramin and Svoboda 2009).

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Sources: Data received from SLOCOG in 2021 and from CBEC Engineering in 2020, and downloaded from City of San Luis Obispo in 2020 and County of San Luis Obispo in 2020
Figure 50 Disadvantaged Communities and 100
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-year and 500-year Flood Plains

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Sources: Data received from SLOCOG in 2021 and from CBEC Engineering in 2020, and downloaded from City of San Luis Obispo in 2020 and County of San Luis Obispo in 2020
Figure 51 Low
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Sources: Data downloaded from OEHHA in 2021 and received from CBEC Engineering in 2020, and downloaded from City of San Luis Obispo in 2020 and County of San Luis Obispo in 2020
Figure 52 Hazardous Material Clean Up Sites and Flood Plains in the City DRAFT

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Sources: Data downloaded from US Census in 2019, City of San Luis Obispo in 2020 and County of San Luis Obispo in 2020 Figure 53 Location and Relative Density of Homeless Encampments in the City of San Luis Obispo DRAFT

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Community Flooding Concerns
As part of the community priorities survey, when participants were asked to report on their level of concern for flooding, as shown in Figure 54, 70 percent of respondents indicated that they were “Somewhat” or “Very Concerned” about the issue. When asked about whether they had been impacted by flooding in the last 1-3 years, only 15 percent of respondents indicated “Somewhat” or “Very”. Additionally, individuals with a household income of less than $50,000 and individuals aged 18 to 24 reported the highest level of concern for flooding. Individuals who identify as all other races and ethnicities, compared to individuals who identify as white or caucasian, also expressed a higher level of concern for flooding (i.e., 36 percent v. 24 percent, respectively).

Sources: Resilient SLO Community Priorities Survey
Figure 54 City Resident’s Flooding Concern and Impact
Key Findings and Policy Considerations
 For all flooding events (i.e., 100-year and 500-year flood events), access to the Southern Gateway of US 101 is compromised due to potential flooding of US 101 and Los Osos Valley Road. However, all centroids under these scenarios are able to access at least one alternative City gateway, which means no portions of the City would be closed off due to roadway network flooding.
 The 500-year flood scenario, illustrated in Figure 42, shows an inability of four census block groups to access either the City gateways or evacuation centers as they experience extensive flooding, isolating their ability to connect to a route.
 There is significant overlap between areas in the City where disadvantaged communities have been identified and the 100- and 500-year floodplain, resulting in potentially disproportionate impacts on these populations in the City during large storm events.
 The area West of South Higuera Street (Census Tract 115.01) is located almost entirely within the 100- and 500- year flood plain which is anticipated to expand in the future due to climate change. This area is particularly vulnerable with high percentage of elderly residents (17 percent) as well as a high percent of disabled residents (15 precent), presenting potential challenges during emergency evacuation events.  Increased heavy precipitation and flooding will disproportionately impact homeless populations because they occupy marginal areas, they are less able to transport themselves out of flood areas during these events. 31%
44%
26%
85%
13%
2%
0%
20%
40%
60%
80%
100%
Not at all Somewhat Very
Percent of Respondents
Level of Concern

FLOODING CONCERN & IMPACT
Which of the following climate change impacts are you concerned about [Flooding]? Which of these hazards have you been personally affected by in the past 1-3 years in the City of San Luis Obispo [Flooding]?
Total Responses = 328
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2.6.3 Adaptive Capacity for Precipitation and Flooding Impacts Adaptive Capacity Rating: Medium/Low
Given its geographical location and the presence of several waterways within its boundaries, the City has been subject to a number of significant flooding events in the past. As a result, the City has taken considerable steps to analyze potential impacts from larger flooding events and mitigate the effects of these events when they do occur. Annex G of the Multi-Jurisdictional Hazard Mitigation Plan (San Luis Obispo County 2019b) includes a thorough analysis of flooding impacts from the 100-year and 500-year storm events, assessing the critical facilities that would be affected by these storms. Annex G also includes a capability assessment that provides an inventory of existing regulatory tools (e.g., ordinances, plans), personnel resources, financial resources (e.g., grants, fees), and partnerships that are currently used or could be used in the future to implement hazard mitigation activities.

Although the City has some authority under the City’s Municipal Code for emergency removal of vegetation and other debris, general maintenance of the creeks falls upon the owners of property adjacent to the creek. Additionally, the creek corridor is highly confined in areas, particularly through downtown, making projects such as channel widening infeasible. Following the 1973 flood, the George S. Nolte & Associates study, completed in 1977, identified proposed flood control projects, but few were adopted because of the environmental effects associated with channel widening and other alternatives (Questa Engineering Corporation 2003). Several areas of the City, including downtown areas along San Luis Obispo Creek, the intersection of U.S. 101 and Los Osos Valley Road, the Johnson Avenue railroad underpass, and areas surrounding Laguna Lake, have been at a high risk for frequent flooding (City of San Luis Obispo 2011). To address these issues, large projects have been proposed to manage flood risk in the increasingly urbanized City. One such project is a high-flow bypass channel for the confluence of Laguna Lake and (the upstream portion) Prefumo Creek. An additional proposed project is the Mid-Higuera Bypass Project, which would increase conveyance capacity of San Luis Obispo Creek between Marsh Street and Madonna Road. This area, downstream of the confluence of Stenner and San Luis Obispo Creeks, has flooded and received extensive damage in some of the historical floods previously mentioned. The planned removal of sediment and Arundo stands from San Luis Obispo Creek south of Los Osos Valley Road will also serve to reduce local flood risk.

In 2003, the City developed and adopted its current Waterway Management Plan in coordination with the San Luis Obispo County Flood Control and Water Conservation District Zone 9 Advisory Committee (Questa Engineering Corporation 2003). The purpose of this plan is to adopt an approach and schematic plans to address flooding, erosion, water quality, and ecological issues in the San Luis Obispo Creek Watershed that can be implemented with approval from various regulatory agencies.

The plan includes five key components to achieve the plan’s objective. These include the following:
 Stream Maintenance and Management Program and guidance document for routine stream maintenance;  New Drainage Design Manual for storm water, flood control, and bank repair design;  Flood Management Plan that outlines the conceptual flood control alternatives;  Bank Stabilization Program that provides a management framework and conceptual plans for addressing current and future bank instability problem areas; and
 Habitat Enhancement and Restoration Program that provides a conceptual plan and framework for stream resource enhancement, restoration, and protection.

The City is currently enrolled in the State’s mandated National Pollution Discharge Elimination System Program which includes requirements to help manage urban stormwater. One of the Best Management Practices (BMP) included in these requirements are practices to address sediment and debris in the storm drain system so the material/pollutants can be removed, and the capacity can be restored to system and allow it to function as designed. The City has undertaken this BMP and achieve
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system. In the first 5 years of this BMP, over 80 percent of the storm drain system was restored and was able to convey water from the streets to the creeks and drainages under full capacity (City of San Luis Obispo, Otte pers. comm., 2021).

In current practice, the stormwater management system for the City is designed to manage small and large storm events based on characteristics of rainfall specific to the region from observed historical data. These characteristics are described using the intensity, duration, frequency (IDF) curves of historic storm events. These IDF curves are used to design various components of urban drainage systems including pipes, culverts, and waterway channels. Given that the City’s existing water management system has been designed and built to manage historic precipitation levels, this infrastructure can be difficult to retrofit and adjust to manage larger storm events, limiting the City’s options for managing more intense storm events due to climate change (CEC 2018).

For the reasons discussed above, the adaptive capacity ranking for increased precipitation and flooding is medium/low.

2.6.4 Vulnerability Summary
Under existing conditions, without the influence of climate change, the City has experienced larger scale flood events in the past. As discussed in Sections 2.5.1 and 2.5.2, the City is particularly vulnerable to increased future flooding risk due to climate change with the intensity and frequency of large storm events increasing significantly by the end of the century. Because the City’s existing stormwater management and flood management infrastructure have been designed and built to manage historic flood events, as the size of large storm events increases, the City’s existing infrastructure will be compromised in its ability to successfully manage these events. Flooding impacts on the City’s physical infrastructure could result in secondary impacts including interruptions to the City’s evacuation routes as discussed in Section 2.5.2, impacts to life and property for homes and businesses located in existing floodplains and new more extensive floodplains, faster degradation of infrastructure, and economic impacts during post-disaster recovery. Based on the analysis of various impacts discussed above, the City’s potential impact scoring is High (3).

Precipitation and flooding impacts that are unique to the City and should be given increased consideration during the adaptation strategy development process are discussed below.

Natural Systems Findings
 Although annual precipitation is anticipated to increase in the City and the larger central coast region, California’s climate oscillates between extremely dry and extremely wet periods with annual precipitation varying widely from year to year. These oscillations between extremely dry and extremely wet periods are anticipated to become more severe with rapid shifts from dry to wet periods known as “whiplash events” (Swain et al. 2016). These types of events are estimated to increase by approximately 100 percent in southern California, with increases in frequency occurring largely after 2050 (Swain et al. 2016).
 Based on California’s location next to the Pacific Ocean, the state is exposed to the atmospheric river (AR) phenomenon, a narrow corridor of concentrated moisture in the atmosphere. The presence of the AR contributes to the frequency of “wet years” in the state, when there is an above-average number of AR storms and aboveaverage annual precipitation. While research indicates that the frequency of large storms events does increase in these wet years, the most severe flooding from ARs may not be in wet years (Swain et al. 2018). The largest flooding impacts are caused by persistent storm sequences on sub-seasonal timescales (i.e., short time periods, typically 2 weeks to 3 months), which bring a significant fraction of annual average precipitation over a brief period. Based on current climate modeling, the frequency of these large storm sequences over short timeframes is projected to increase noticeably under a future high emissions scenario. It is estimated that a storm similar in magnitude to the Great Flood events is more likely than not to occur at least once between 2018 and 2060 (Swain et al. 2018).  For very large precipitation events, the capacity of the watershed to absorb incoming rainfall can be quickly exceeded, causing large increases in stream flow within the system. By as early as 2070 under a high future emissions scenario, peak flow rates in the San Luis Obispo Creek watershed are projected to increase, on average, from 17 percent to 38 percent depending on the size of the storm event. By this period DRAFT
, for the storm event with a

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50 percent chance of occurring in any given year (2-year storm event), the median peak stream flow is projected to increase by 28 percent with a small likelihood (90th percentile) of stream flow increasing by 51 percent.

Built Environment Findings
 By as early as 2070 under a high future emissions scenario, for the 100-year event, dramatic increases are observed on Stenner and Old Garden Creeks upstream of the San Luis Obispo Creek confluence and within the downtown area. In both cases, flooding is exacerbated by the capacity of the existing infrastructure to manage historic flooding events. Similar, during the 100-year event, increases in flow within San Luis Obispo Creek increasingly cause flood waters to break out of the channel upstream of the culvert and flow along the Higuera and Marsh Street corridor towards the Stenner Creek confluence  From the results of the climate-informed flood modeling, areas with the greatest increases in connected floodplain inundation for the 10-year through 100-year events included SLO Creek upstream of the Stenner confluence (including parts of downtown SLO), the SLO Creek – Prefumo Creek confluence area, East Fork and its tributaries upstream of Buckley Road, and Stenner, Brizziolari, and Old Garden Creeks. In the modeling, these areas tended to have greater expanses of floodplain areas, such as the SLO Creek – Prefumo Creek confluence area, or limiting infrastructure, as is the case with the undercity culvert through downtown.  By as early as 2070 under a high future emissions scenario, for the 100-year event, dramatic increases are observed on Stenner and Old Garden Creeks upstream of the San Luis Obispo Creek confluence and within the downtown area. In both cases, flooding is exacerbated by the capacity of the existing infrastructure to manage historic flooding events. Similar, during the 100-year event, increases in flow within San Luis Obispo Creek increasingly cause flood waters to break out of the channel upstream of the culvert and flow along the Higuera and Marsh Street corridor towards the Stenner Creek confluence.  Near the San Luis Obispo – Prefumo Creek confluence area near Higuera Street and Madonna Road, large expanses of relatively flat, low-lying land persist between and along the two creeks. During larger storm events (50-year and 100-year storms), flood waters can spill into these areas by crossing Highway 101 near Madonna Road from San Luis Obispo Creek or by escaping the creek channels in the confluence area and causing backwater conditions for upstream reaches.
 The greatest area of impact to local roads during large storm events (100-year storm) would be areas just south of San Luis Obispo Creek through the downtown area with the farthest extent along Santa Barbara Street as far South as Leff Street. The Chorro Street undercrossing at US 101 would be impacted by the 10-year, 100-year, and 500-year floods.
 Extensive flooding from larger storm events also has the potential to limit transit service, thus eliminating transport options for populations in the City dependent on transit, with between 16 to 26 percent of SLO Transit stops being affected depending on the storm size.

Community Resilience Findings
 For all flooding events (i.e., 100-year and 500-year flood events), access to the Southern Gateway of US 101 is compromised due to potential flooding of US 101 and Los Osos Valley Road. However, all centroids under these scenarios are able to access at least one alternative City gateway, which means no portions of the City would be closed off due to roadway network flooding.
 The 500-year flood scenario, illustrated in Figure 42, shows an inability of four census block groups to access either the City gateways or evacuation centers as they experience extensive flooding, isolating their ability to connect to a route.
 There is significant overlap between areas in the City where disadvantaged communities have been identified and the 100- and 500-year floodplain, resulting in potentially disproportionate impacts on these populations in the City during large storm events.

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 The area West of South Higuera Street (Census Tract 115.01) is located almost entirely within the 100- and 500- year flood plain which is anticipated to expand in the future due to climate change. This area is particularly vulnerable with high percentage of elderly residents (17 percent) as well as a high percent of disabled residents (15 precent), presenting potential challenges during emergency evacuation events.  Increased heavy precipitation and flooding will disproportionately impact homeless populations because they occupy marginal areas, they are less able to transport themselves out of flood areas during these events.

Adaptive Capacity: Medium/Low (2.5)
Potential Impact: High (3)
Vulnerability Score: 4.5
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City of San Luis Obispo
Climate Change Hazards and Vulnerability Report 3-1
3 VULNERABILITY SCORING SUMMARY
As described in this Report, the City’s vulnerability to each identified impact has been assessed based on the magnitude of risk to and potential impacts on Natural Systems, the Built Environment, and Community Resilience.

Importantly, the assessment also considers the City’s current adaptive capacity to mitigate these climate-related hazards when impacts do occur. Table 23 presents a list of important plans, resources, and documents that already exist and are being used to help mitigate risk from these climate-related hazards.

Table 23 Summary of Existing Plans and Reports
Plan or Report
Climate Change Hazard
Increased
Temperatures and
Extreme Heat
Increased
Wildfire Risk
Increased
Precipitation and
Flooding
Drought and Water
Supply
California’s Fourth Climate Change Assessment, Central Coast Region Report
✓ ✓ ✓ ✓
City Local Hazard Mitigation Plan Annex ✓ ✓ ✓
City General Plan ✓ ✓ ✓
City Emergency Operations Plan ✓ ✓
Waterway Management Plan ✓
City Community Wildfire Protection Plan ✓
City Urban Water Management Plan ✓
City Open Space Vegetation Management Plan ✓
Source: Ascent Environmental 2021
Based on the ratings of potential impacts and adaptive capacity, an overall vulnerability score was determined for each climate change effect. This scoring process can help the City understand which effects pose the greatest threats and should be prioritized in future planning efforts.

As shown in Table 24, increased extreme precipitation and flooding is assigned a vulnerability rating of 4.5 and has the highest vulnerability score. Increases in temperature and extreme heat as well as increase wildfire risk are both given a vulnerability score of 4. Although ranked slightly lower, these climate change effects are also likely to have significant impacts on the City in the near-term and midterm periods. Although a variety of adaptive efforts related to both climate change effects are in place and underway, the magnitude of the impacts posed by these hazards contributes to high vulnerability for the City and its populations. Finally, increased long-term drought is characterized as having a vulnerability rating of 3.5. This climate change effect is currently being addressed adequately based on existing conditions, but additional adaptation and resilience planning will still be required in the future to mitigate impacts and protect the City.

Table 24 Summary of Vulnerability Scoring
Climate Change Effect
Vulnerability Score
Adaptive Capacity Potential Impact Vulnerability
Increased Extreme Precipitation and Flooding Medium/Low High 4.5 Increased Temperatures and Extreme Heat Low Medium 4
Increased Wildfire Medium High 4
Long-Term Drought High Medium 3.5
Source: Ascent Environmental in 2021
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Provided below is a summary of impacts that are unique to the City for each of the four climate-related hazards and should be given increased consideration during the adaptation strategy development process are discussed below.

TEMPERATURES AND EXTREME HEAT KEY FINDINGS
Natural System Findings
 Changes in temperature and extreme heat are likely to have negative impacts on the City’s tree canopy with some tree species no longer suitable for future minimum and maximum temperatures. Any future policies focused on improving the City’s tree canopy or green spaces to mitigate the urban heat island effect should carefully consider what plant and tree species will be suitable for future climate conditions.  Climate change is projected to encourage the spread of invasive species in the City’s open spaces, affecting coastal sage scrub habitats as well as the City’s oak species from Sudden Oak Death.  Regional impacts on agriculture and viticulture industries from shifting temperatures have the potential to impact the City via decreases in wine and vineyard-based tourism, with the City relying heavily on revenue and employment opportunities in these industries. Resilience strategies focused on economic impacts should consider potential impacts on viticulture vineyard-based tourism and potential diversification of the City’s tax revenue sources and employment industries.

Built Environment Findings
 The Margarita Avenue Neighborhood (Census Tract 111.03) includes population characteristics that make this area particularly vulnerable to extreme heat and is located in an area of the City with increased urban heat island severity. Resilience strategies that mitigate impacts of the urban heat island effect should focus on supporting this area of the City.
 Shifts in temperature and extreme heat will result in changes in energy demand for cooling in the City, with increased demand in areas experiencing more severe urban heat island hotspots. As the City implements it’s recently adopted Climate Action Plan and as well as the Resilient SLO strategies, solutions that both reduce GHG emissions and help the City adapt to impacts of climate change should be prioritized.  The City’s historically moderate climate has, in general, not required the City’s existing building stock to be designed or equipped with air conditioning. However, as average temperatures and extreme heat events increase in the future, residents are ill-equipped to prepare for these events. Additionally, increases in temperature and extreme heat will result in increased energy demand for cooling, which underscores the need to support distributed energy resources, customer sited energy storage, demand response, and grid/building connected appliances and vehicles.
 Extreme heat days and heat waves will have a disproportionate impact on electricity demand, with higher electricity demand projected for these events in the future. These projections place an increased urgency on electricity utilities to plan for higher electricity demand during these events in future.

Community Resilience Findings
 The Margarita Avenue Neighborhood (Census Tract 111.03) West of South Higuera neighborhood (Census Tract 115.01) is an area of the city with a particularly vulnerable population in regard to extreme heat, with a high percentage of elderly, disabled, or low-income residents. The West of South Higuera neighborhood (Census Tract 115.01) also includes a high percentage of elderly and disabled residents, making this area particularly vulnerable to extreme heat impact.
 Low-income residents are particularly vulnerable to extreme heat impacts due to a number of factors including a higher reliance on public transit (leaving these residents more exposed to extreme heat during transit use), a higher percentage of income being devoted toward utility bills, and a trend of lower income neighborhoods having less tree cover. Unhoused individuals are also at increased risk from extreme heat events with, generally, less access to places to cool off and healthcare resources during these eve DRAFT
nts.

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 The City and the County, in general, have historically served as a destination for summer tourists to escape more extreme summer heat in the San Joaquin Valley and southern California. As extreme heat events continue to increase disproportionately in those areas of the state compared to less severe increases locally, the City may experience increases in this phenomenon placing increased demand on services, impacts on City infrastructure and resources, as well increased pressure on the housing shortage issue in the City from new permanent residents.

LONG-TERM DROUGHT KEY FINDINGS
Natural System Findings
 The City’s designated open space areas include a mixture of vegetation types including oak woodland, grassland, coastal sage scrub, and chaparral that are anticipated to be impacted by changes in annual average temperatures, extreme heat, and long-term droughts (OPR et al. 2018b).  As dry years and long-term droughts become more common in the future, population growth rates of annual plant species will become marginal, and populations are likely to become locally extinct.

Built Environment Findings
 Dramatic shifts from a multi-year dry periods to wet periods, similar to the 2011-2015 drought followed by an above average wet year in the 2016-2017, are known as whiplash events (Swain et al. 2018), and are expected to become more severe in the future. These whiplash events may affect water supply management practices over the long-term, particularly as the swings from multi-year dry to wet periods become more prolonged and more severe, with an emphasis on increasing rainfall storage when it does occur during the wet periods (Persad et al. 2020).
 Buildup of sedimentation that reduces a reservoir’s volume available already occurs in the City’s water storage system, with the City implementing programs and policies to address this storage loss over the long term. However, landscape disturbances including wildfire, post-wildfire runoff, or landslides after wet winters, are projected to increase sediment yield from watersheds along the Central Coast (OPR et al. 2018b) and with the potential to further reduce the amount of water-storage capacity in dammed Central Coast reservoirs (Smith et al. 2018).  The City’s 2020 UWMP modeled potential impacts on the City’s water supplying, finding that changes in precipitation could result in a decrease of as much as 850 AFY to an increase of as much as 160 AFY, accounting for an approximately 8 percent decrease to 2 percent increase in the City’s overall water supply (City of San Luis Obispo 2021b).
 With more rapid shifts from dry to wet periods known as “whiplash events,” precipitation will occur over shorter more intense periods. This shift has the potential to reduce groundwater recharge which ideally occurs during prolonged wet periods to allow for soil infiltration, deeper percolation, and more effective groundwater recharge.

However, increases in the intensity of rainfall events, when they do occur in the wet periods, provides an opportunity to offset potential losses in storage during periods of drought.  The 2020 UWMP includes a section specially on Water Resiliency Planning which highlights a set of strategies the City has taken to ensure long-term water resiliency and mitigate the impacts from a long-term drought scenario.

These strategies include a multi-source water supply; conservative water demand projections; water use efficiency; water recycling; and future groundwater recharge.

Community Resilience Findings
 Increases in temperature and extreme heat events are associated with increases in vector-borne and infectious disease transmission, with future long-term drought scenarios potentially increasing the prevalence of certain vector-borne diseases present on in the central coast region DRAFT
including Lyme disease and valley fever.

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WILDFIRE KEY FINDINGS
Natural System Findings
 The increasing frequency of fire on chaparral landscapes have caused coastal sage shrubs and chaparral to shift to grasses, including exotic grasses. Some research has suggested that annual and some perennial grasses have the strongest effects on fire regimes and act as ecosystem transformers.  Wildfire impacts in riparian zones can reduce canopy cover, resulting in increased water temperatures in creeks and other shaded waterways as well as produce increased sediment flux in stream beds and adjacent areas, affecting the food web of burned stream areas and increasing the density of algae in waterways.  Post-wildfire runoff and debris flows can be affected by several factors but are generally triggered by one of two processes: surface erosion caused by rainfall runoff, and landslides caused by rainfall seeping into the ground.

While it is uncertain the effect climate change will have on post-wildfire runoff and debris flows event, climate change is projected to result in higher intensity rainfall events as well as “whiplash events” with oscillations between extremely dry and extremely wet periods, potentially affecting post-wildfire hazards.

Built Environment Findings
 The risk of wildfire is dependent on a variety of factors not excluding biophysical factors that are affected by climate change including Resources (e.g., land use patterns, vegetation growth), Ignitions (e.g., lightning, accidental ignitions, arson), and Conditions (e.g., precipitation, wind, seasonal variation). Approximately 95 percent of wildfires in the state are caused by human ignition. However, climate change is projected to increase the frequency and severity of wildfires, when they do occur (Mann et al. 2016).  The combination of dry climate conditions and the seasonal high autumn winds in California can increase the risk of trees or branches falling on transmission lines and causing power outages or wildfires. While these events have occurred historically, the effect of climate change on biophysical features that increase the risk of wildfires (e.g., precipitation, wind, seasonal variation) will increase the frequency and severity of wildfires from transmission line ignitions.
 There was limited development within the WUI in the city for the period of 2001 – 2016, with a few prominent exceptions including the Madonna Area and the Margarita Area to the east of South Higuera Street. However, buildings outside of the WUI are also at risk from ignition due to the spread of firebrands (or embers) that can initiate new spot fires.
 Wildfire events in the VHFHSZ near the Irish Hills Natural Reserve could potentially have immediate impacts to some residential areas on Royal Way, Sterling Lane and Isabella Way. Additionally, areas in the northeast of the City south of US 101 along San Luis Road are at risk from wildfire impacts and could potentially compromise evacuation management when wildfires do occur in this area.

Community Resilience Findings
 The City serves as regional employment center, regional destination for tourism, and home to a university (Cal Poly) with approximately 20,000 students. These factors create an environment in which the City experiences a large influx of daily visitors to the City. If and when a wildfire event were to occur in or near the City during daytime hours, evacuation management would be particularly difficult and pose additional challenges due to this large influx of daily visitors. Additionally, because US 101 serves the main commuter corridor for locations north and south, wildfire events that occur along this route causing route closures (e.g., Cuesta Grade) can have disproportionate impact on employers and employees in the City.  While the majority of the City is not at high risk from direct wildfire impacts, regional PSPSs events that affect the City will result in a set of potential secondary impacts. Specifically, PSPS events occurring during heat wave events could have considerable public health impacts, leaving residents and businesses without power and air conditioning and create health impacts to those who are reliant of electricity f DRAFT
or supplemental oxygen and refrigerated medications.

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 The confluence of PSPS, bad air quality, wildfire threat, and high heat days underscores the importance of homes and businesses as places of potential refuge.
 The Sinsheimer Neighborhood (Census Tract 110.01) and the Laguna Lake and Los Osos Valley Road (Census Tract 113) are particularly vulnerable to wildfire impacts with this areas of the City near moderate to very high FHSZs and include the higher percentages of elderly (20 percent) and youth (7 percent) populations as well as the Laguna Lake and Los Osos Valley Road area with a high percentage of households experiencing linguistic isolation (8 percent) which may present issues during emergency evacuation events.

Exposure to wildfire smoke, particularly exposure to vulnerable populations, can result in worsening of respiratory symptoms, increased rates of cardiorespiratory emergency visits, hospitalizations, and even death (Rappold et al. 2017). Wildfires can damage not only buildings and infrastructure, but also the natural environment, including portions of the City and the areas in the County that serve as regional recreation and tourism opportunities, resulting in economic impacts on the tourism and related industries when wildfire smoke impacts occur.

Precipitation Key Considerations
Natural Systems Findings
 Although annual precipitation is anticipated to increase in the City and the larger central coast region, California’s climate oscillates between extremely dry and extremely wet periods with annual precipitation varying widely from year to year. These oscillations between extremely dry and extremely wet periods are anticipated to become more severe with rapid shifts from dry to wet periods known as “whiplash events” (Swain et al. 2016). These types of events are estimated to increase by approximately 100 percent in southern California, with increases in frequency occurring largely after 2050 (Swain et al. 2016).
 Based on California’s location next to the Pacific Ocean, the state is exposed to the atmospheric river (AR) phenomenon, a narrow corridor of concentrated moisture in the atmosphere. The presence of the AR contributes to the frequency of “wet years” in the state, when there is an above-average number of AR storms and aboveaverage annual precipitation. While research indicates that the frequency of large storms events does increase in these wet years, the most severe flooding from ARs may not be in wet years (Swain et al. 2018). The largest flooding impacts are caused by persistent storm sequences on sub-seasonal timescales (i.e., short time periods, typically 2 weeks to 3 months), which bring a significant fraction of annual average precipitation over a brief period. Based on current climate modeling, the frequency of these large storm sequences over short timeframes is projected to increase noticeably under a future high emissions scenario. It is estimated that a storm similar in magnitude to the Great Flood events is more likely than not to occur at least once between 2018 and 2060 (Swain et al. 2018).  For very large precipitation events, the capacity of the watershed to absorb incoming rainfall can be quickly exceeded, causing large increases in stream flow within the system. By as early as 2070 under a high future emissions scenario, peak flow rates in the San Luis Obispo Creek watershed are projected to increase, on average, from 17 percent to 38 percent depending on the size of the storm event. By this period, for the storm event with a 50 percent chance of occurring in any given year (2-year storm event), the median peak stream flow is projected to increase by 28 percent with a small likelihood (90th percentile) of stream flow increasing by 51 percent.

Built Environment Findings
 By as early as 2070 under a high future emissions scenario, for the 100-year event, dramatic increases are observed on Stenner and Old Garden Creeks upstream of the San Luis Obispo Creek confluence and within the downtown area. In both cases, flooding is exacerbated by the capacity of the existing infrastructure to manage historic flooding events. Similar, during the 100-year event, increases in flow within San Luis Obispo Creek increasingly cause flood waters to break out of the channel upstream of the culvert and flow along the Higuera and Marsh Street
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corridor towards the Stenner Creek confluence

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 From the results of the climate-informed flood modeling, areas with the greatest increases in connected floodplain inundation for the 10-year through 100-year events included SLO Creek upstream of the Stenner confluence (including parts of downtown SLO), the SLO Creek – Prefumo Creek confluence area, East Fork and its tributaries upstream of Buckley Road, and Stenner, Brizziolari, and Old Garden Creeks. In the modeling, these areas tended to have greater expanses of floodplain areas, such as the SLO Creek – Prefumo Creek confluence area, or limiting infrastructure, as is the case with the undercity culvert through downtown.  By as early as 2070 under a high future emissions scenario, for the 100-year event, dramatic increases are observed on Stenner and Old Garden Creeks upstream of the San Luis Obispo Creek confluence and within the downtown area. In both cases, flooding is exacerbated by the capacity of the existing infrastructure to manage historic flooding events. Similar, during the 100-year event, increases in flow within San Luis Obispo Creek increasingly cause flood waters to break out of the channel upstream of the culvert and flow along the Higuera and Marsh Street corridor towards the Stenner Creek confluence.  Near the San Luis Obispo – Prefumo Creek confluence area near Higuera Street and Madonna Road, large expanses of relatively flat, low-lying land persist between and along the two creeks. During larger storm events (50-year and 100-year storms), flood waters can spill into these areas by crossing Highway 101 near Madonna Road from San Luis Obispo Creek or by escaping the creek channels in the confluence area and causing backwater conditions for upstream reaches.
 The greatest area of impact to local roads during large storm events (100-year storm) would be areas just south of San Luis Obispo Creek through the downtown area with the farthest extent along Santa Barbara Street as far South as Leff Street. The Chorro Street undercrossing at US 101 would be impacted by the 10-year, 100-year, and 500-year floods.
 Extensive flooding from larger storm events also has the potential to limit transit service, thus eliminating transport options for populations in the City dependent on transit, with between 16 to 26 percent of SLO Transit stops being affected depending on the storm size.

Community Resilience Findings
 For all flooding events (i.e., 100-year and 500-year flood events), access to the Southern Gateway of US 101 is compromised due to potential flooding of US 101 and Los Osos Valley Road. However, all centroids under these scenarios are able to access at least one alternative City gateway, which means no portions of the City would be closed off due to roadway network flooding.
 The 500-year flood scenario, illustrated in Figure 42, shows an inability of four census block groups to access either the City gateways or evacuation centers as they experience extensive flooding, isolating their ability to connect to a route.
 There is significant overlap between areas in the City where disadvantaged communities have been identified and the 100- and 500-year floodplain, resulting in potentially disproportionate impacts on these populations in the City during large storm events.
 The area West of South Higuera Street (Census Tract 115.01) is located almost entirely within the 100- and 500- year flood plain which is anticipated to expand in the future due to climate change. This area is particularly vulnerable with high percentage of elderly residents (17 percent) as well as a high percent of disabled residents (15 precent), presenting potential challenges during emergency evacuation events.  Increased heavy precipitation and flooding will disproportionately impact homeless populations because they occupy marginal areas, they are less able to transport themselves out of flood areas during these events.

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DRAFT .

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DRAFT
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DRAFT

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City of San Luis Obispo
4-6 Climate Change Hazards and Vulnerability Report
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DRAFT

Appendix A
Flood Risk Modeling and
Wildland Urban Interface Maps
DRAFT

Islay Hill
Terrace
Hill
Reservior Canyon
Natural Reserve
Johnson Ranch
Bishop Peak
Natural Reserve
Irish Hills
Natural Reserve
South Hills
Laguna Lake
Natural Reserve
Miossi
Open Space
Rigetti
Hill
ab101
ab101
ÃÅ1
ÃÅ227
0 5,000 10,000
FEET
Model Reaches
Model Cross Sections
San Luis Obispo City Limits
Digital Elevation Model
Elevation NAVD88 (ft)

0.0 2763
Stenner Creek
Brizziolari Creek
Stenner - O dl Gardens Creeks
Prefumo Creek
San Luis Obispo
Creek
East Fork
San Luis Obispo Creek
San Luis Obispo Creek

SLO-4
STEN
SLO-5
0 500 1,000
FEET
San Luis Obispo City Limits
Digital Elevation Model
Elevation NAVD88 (ft)

0.0 2763
Analysis Regions
Excluded Areas
Q10 (Historic)
Depth (ft)
0 - 1
1 - 2
2 - 3
3 - 4
4 - 5
> 5
San Luis Obispo Creek
Ste
n
n
e
r
C
r
e
e
k
Old
Garden
Creek

SLO-4
STEN
SLO-5
0 500 1,000
FEET
San Luis Obispo City Limits
Digital Elevation Model
Elevation NAVD88 (ft)

0.0 2763
Analysis Regions
Excluded Areas
Q10 (Future)
Depth (ft)
0 - 1
1 - 2
2 - 3
3 - 4
4 - 5
> 5
San Luis Obispo Creek
Ste
n
n
e
r
C
r
e
e
k
Old
Garden
Creek

SLO-4
STEN
SLO-5
0 500 1,000
FEET
San Luis Obispo City Limits
Digital Elevation Model
Elevation NAVD88 (ft)

0.0 2763
Analysis Regions
Excluded Areas
Q100 (Historic)
Depth (ft)
0 - 1
1 - 2
2 - 3
3 - 4
4 - 5
> 5
San Luis Obispo Creek
Ste
n
n
e
r
C
r
e
e
k
Old
Garden
Creek

SLO-4
STEN
SLO-5
0 500 1,000
FEET
San Luis Obispo City Limits
Digital Elevation Model
Elevation NAVD88 (ft)

0.0 2763
Analysis Regions
Excluded Areas
Q100 (Future)
Depth (ft)
0 - 1
1 - 2
2 - 3
3 - 4
4 - 5
> 5
San Luis Obispo Creek
Ste
n
n
e
r
C
r
e
e
k
Old
Garden
Creek

SLO-4
LGNA
SLO-2
SLO-3
Laguna Lake 0 500 1,000
FEET
San Luis Obispo City Limits
Digital Elevation Model
Elevation NAVD88 (ft)

0.0 2763
Analysis Regions
Excluded Areas
Q10 (Historic)
Depth (ft)
0 - 1
1 - 2
2 - 3
3 - 4
4 - 5
> 5
San
Luis
Obispo Creek
Prefu
m
o
Cre
e
k

SLO-4
LGNA
SLO-2
SLO-3
Laguna Lake 0 500 1,000
FEET
San Luis Obispo City Limits
Digital Elevation Model
Elevation NAVD88 (ft)

0.0 2763
Analysis Regions
Excluded Areas
Q10 (Future)
Depth (ft)
0 - 1
1 - 2
2 - 3
3 - 4
4 - 5
> 5
San
Luis
Obispo Creek
Prefu
m
o
Cre
e
k

SLO-4
LGNA
SLO-2
SLO-3
Laguna Lake 0 500 1,000
FEET
San Luis Obispo City Limits
Digital Elevation Model
Elevation NAVD88 (ft)

0.0 2763
Analysis Regions
Excluded Areas
Q100 (Historic)
Depth (ft)
0 - 1
1 - 2
2 - 3
3 - 4
4 - 5
> 5
San
Luis
Obispo Creek
Prefu
m
o
Cre
e
k

SLO-4
LGNA
SLO-2
SLO-3
Laguna Lake 0 500 1,000
FEET
San Luis Obispo City Limits
Digital Elevation Model
Elevation NAVD88 (ft)

0.0 2763
Analysis Regions
Excluded Areas
Q100 (Future)
Depth (ft)
0 - 1
1 - 2
2 - 3
3 - 4
4 - 5
> 5
San
Luis
Obispo Creek
Prefu
m
o
Cre
e
k

ab101
ab101
ÃÅ1
ÃÅ227
SLO-4
LGNA
SLO-2
SLO-1
SLO-3
EFK-1
EFK-2
STEN
SLO-5
Laguna Lake
0 2,500 5,000
FEET
San Luis Obispo City Limits
Digital Elevation Model
Elevation NAVD88 (ft)

0.0 2763
Analysis Regions
Excluded Areas
Q10 (Historic)
Depth (ft)
0 - 1
1 - 2
2 - 3
3 - 4
4 - 5
> 5

ab101
ab101
ÃÅ1
ÃÅ227
SLO-4
LGNA
SLO-2
SLO-1
SLO-3
EFK-1
EFK-2
STEN
SLO-5
Laguna Lake
0 2,500 5,000
FEET
San Luis Obispo City Limits
Digital Elevation Model
Elevation NAVD88 (ft)

0.0 2763
Analysis Regions
Excluded Areas
Q10 (Future)
Depth (ft)
0 - 1
1 - 2
2 - 3
3 - 4
4 - 5
> 5

ab101
ab101
ÃÅ1
ÃÅ227
SLO-4
LGNA
SLO-2
SLO-1
SLO-3
EFK-1
EFK-2
STEN
SLO-5
Laguna Lake
0 2,500 5,000
FEET
San Luis Obispo City Limits
Digital Elevation Model
Elevation NAVD88 (ft)

0.0 2763
Analysis Regions
Excluded Areas
Q50 (Historic)
Depth (ft)
0 - 1
1 - 2
2 - 3
3 - 4
4 - 5
> 5

ab101
ab101
ÃÅ1
ÃÅ227
SLO-4
LGNA
SLO-2
SLO-1
SLO-3
EFK-1
EFK-2
STEN
SLO-5
Laguna Lake
0 2,500 5,000
FEET
San Luis Obispo City Limits
Digital Elevation Model
Elevation NAVD88 (ft)

0.0 2763
Analysis Regions
Excluded Areas
Q50 (Future)
Depth (ft)
0 - 1
1 - 2
2 - 3
3 - 4
4 - 5
> 5

ab101
ab101
ÃÅ1
ÃÅ227
SLO-4
LGNA
SLO-2
SLO-1
SLO-3
EFK-1
EFK-2
STEN
SLO-5
Laguna Lake
0 2,500 5,000
FEET
San Luis Obispo City Limits
Digital Elevation Model
Elevation NAVD88 (ft)

0.0 2763
Analysis Regions
Excluded Areas
Q100 (Historic)
Depth (ft)
0 - 1
1 - 2
2 - 3
3 - 4
4 - 5
> 5

ab101
ab101
ÃÅ1
ÃÅ227
SLO-4
LGNA
SLO-2
SLO-1
SLO-3
EFK-1
EFK-2
STEN
SLO-5
Laguna Lake
0 2,500 5,000
FEET
San Luis Obispo City Limits
Digital Elevation Model
Elevation NAVD88 (ft)

0.0 2763
Analysis Regions
Excluded Areas
Q100 (Future)
Depth (ft)
0 - 1
1 - 2
2 - 3
3 - 4
4 - 5
> 5

ab101
ab101
ÃÅ1
ÃÅ227
SLO-4
LGNA
SLO-2
SLO-1
SLO-3
STEN
SLO-5
Laguna Lake
0 2,500 5,000
FEET
San Luis Obispo City Limits
Digital Elevation Model
Elevation NAVD88 (ft)

0.0 2763
Analysis Regions
Excluded Areas
Q500 (Historic)
Depth (ft)
0 - 1
1 - 2
2 - 3
3 - 4
4 - 5
> 5

ab101
ab101
ÃÅ1
ÃÅ227
SLO-4
LGNA
SLO-2
SLO-1
SLO-3
STEN
SLO-5
Laguna Lake
0 2,500 5,000
FEET
San Luis Obispo City Limits
Digital Elevation Model
Elevation NAVD88 (ft)

0.0 2763
Analysis Regions
Excluded Areas
Q500 (Future)
Depth (ft)
0 - 1
1 - 2
2 - 3
3 - 4
4 - 5
> 5

Appendix A Compliance with State Laws and Regulations
Senate Bill 379 (Climate Change Adaptation and Resilience) SB 379 (2015) mandates that climate adaptation and resilience are considered in safety elements. The legislation specifically requires that safety elements include a vulnerability assessment that identifies climate change impacts to the jurisdiction, and a suite of goals, policies, objectives, and feasible implementation measures to protect the community from risks posed by climate change.

Senate Bill 99 (Emergency Evacuation Routes)
SB 99 (2019) requires safety elements to include information that identifies residential developments in hazard areas without at least two emergency evacuation routes.

Assembly Bill 747 (Emergency Evacuation Routes)
Assembly Bill (AB) 747 (2019) requires that safety elements are reviewed and updated as needed to identify evacuation routes and their capacity, safety, and viability under a range of emergency scenarios. An adopted local hazard mitigation plan, emergency operations plan, or other document that fulfills these requirements, may be summarized, and incorporated by reference into the safety element to comply.

Senate Bill 1000 (Environmental Justice)
SB 1000 (2016) requires communities with disadvantaged communities to address environmental justice in the general plan. Disadvantaged communities are defined by State law and generally refer to areas disproportionately affected by environmental pollution or other hazards that can lead to negative health effects, exposure, or environmental degradation.

Under the law, cities and counties with communities that meet the definition of disadvantaged under the law must address unique or compound health risks in these communities, promote civil engagement in the public decision-making process, and prioritize programs and improvements that address the needs of these communities. While the city does not have any State designated disadvantaged communities, some of its populations may be less resilient to hazards due to socioeconomic factors. Therefore, the City has voluntarily chosen to address environmental justice issues through this element.

Alquist-Priolo Earthquake Faulting Zone Act
The Alquist-Priolo Earthquake Faulting Zone Act was passed in 1971 with the intent of reducing risk of loss from surface fault rupture. The act provides guidance for cities on prohibiting development across the trace of active faults.

National Flood Insurance Program
The Federal Emergency Management Agency (FEMA) insures properties against flooding losses through the National Flood Insurance Program. The City has been a participant in the National Flood Insurance Program since April 16, 1979 and will continue to participate and remain in compliance with the National Flood Insurance Program. The City joined the Community Rating System on October 1, 1991, and currently has a Class 6 rating.

CODE+A1A
1:G23 TIMELINE / ENFORCEMENT TOPIC STATE GUIDANCE LEGISLATION § 65302 g.1.

Before preparing or revising its safety element, each city and county shall consult the California Geological Survey of the Department of Conservation, the Central Valley Flood Protection Board, if the city or county is located within the boundaries of the Sacramento and San Joaquin Drainage District, and the Office of Emergency Services for the purpose of including information known by and available to the department, the agency, and the board required by this subdivision.

To the extent that a county’s safety element is sufficiently detailed and contains appropriate policies and programs for adoption by a city, a city may adopt that portion of the county’s safety element that pertains to the city’s planning area in satisfaction of the requirement imposed by this subdivision.
§ 65302 g.1. Hazards
§ 65302 g.1. Hazards
§ 65302 g.2.A.

Cities and counties that have flood plain management ordinances that have been approved by FEMA that substantially comply with this section, or have substantially equivalent provisions to this subdivision in their general plans, may use that information in the safety element to comply with this subdivision, and shall summarize and incorporate by reference into the safety element the other general plan provisions or the flood plain ordinance, specifically showing how each requirement of this subdivision has been met.

Flood
§ 65302 g.2.A.i.

Flood hazard zones. As used in this subdivision, “flood hazard zone” means an area subject to flooding that is delineated as either a special hazard area or an area of moderate or minimal hazard on an official flood insurance rate map issued by FEMA. The identification of a flood hazard zone does not imply that areas outside the flood hazard zones or uses permitted within flood hazard zones will be free from flooding or flood damage.

Flood
§ 65302 g.2.A.ii. National Flood Insurance Program maps published by FEMA. Flood § 65302 g.2.A.iii. Information about flood hazards that is available from the United States Army Corps of Engineers. Flood § 65302 g.2.A.iv. Designated floodway maps that are available from the Central Valley Flood Protection Board. Flood § 65302 g.2.A.ix. Historical data on flooding, including locally prepared maps of areas that are subject to flooding, areas that are vulnerable to flooding after wildfires, and sites that have been repeatedly damaged by flooding. Flood § 65302 g.2.A.v. Dam failure inundation maps prepared pursuant to Section 6161 of the Water Code that are available from the Department of Water Resources. Flood
§ 65302 g.2.A.vi. Awareness Floodplain Mapping Program maps and 200-year flood plain maps that are or may be available from, or accepted by, the Department of Water Resources. Flood § 65302 g.2.A.vii. Maps of levee protection zones. Flood § 65302 g.2.A.viii. Areas subject to inundation in the event of the failure of project or nonproject levees or floodwalls. Flood § 65302 g.2.A.x. Existing and planned development in flood hazard zones, including structures, roads, utilities, and essential public facilities. Flood
§ 65302 g.2.A.xi. Local, state, and federal agencies with responsibility for flood protection, including special districts and local offices of emergency services. Flood
Include mapping of known seismic and other geologic hazards.

Address evacuation routes, military installations, peak load water supply requirements, and minimum road widths and clearances around structures, as those items relate to identified fire and geologic hazards.

Identify information regarding flood hazards, including but not limited to:

LOCAL PLANNING REQUIREMENTS

SAFETY ELEMENT
A safety element for the protection of the community from any unreasonable risks associated with the effects of seismically induced surface rupture, ground shaking, ground failure, tsunami, seiche, and dam failure; slope instability leading to mudslides and landslides; subsidence; liquefaction; and other seismic hazards, and other geologic hazards known to the legislative body; flooding; and wildland and urban fires.

§ 65302 g.2.B. Flood
§ 65302 g.2.B.i. Avoiding or minimizing the risks of flooding to new development. Flood § 65302 g.2.B.ii.

Evaluating whether new development should be located in flood hazard zones, and identifying construction methods or other methods to minimize damage if new development is located in flood hazard zones.

Flood
§ 65302 g.2.B.iii. Maintaining the structural and operational integrity of essential public facilities during flooding. Flood § 65302 g.2.B.iv.

Locating, when feasible, new essential public facilities outside of flood hazard zones, including hospitals and health care facilities, emergency shelters, fire stations, emergency command centers, and emergency communications facilities or identifying construction methods or other methods to minimize damage if these facilities are located in flood hazard zones.

Flood
§ 65302 g.2.B.v. Establishing cooperative working relationships among public agencies with responsibility for flood protection. Flood
§ 65302 g.2.C. Flood
§ 65302 g.3.

Fire safety plan or document separate from the general plan, an attachment of, or reference to, a city or county’s adopted fire safety plan or document that fulfills commensurate goals and objectives and contains information required pursuant to this paragraph.

Fire
OPR Fire Hazard Technical
Advisory (2020 Public Review
Draft)
§ 65302 g.3.A. Fire
§ 65302 g.3.A.i. Fire hazard severity zone maps available from the Department of Forestry and Fire Protection. Fire § 65302 g.3.A.ii. Any historical data on wildfires available from local agencies or a reference to where the data can be found. Fire
§ 65302 g.3.A.iii. Information about wildfire hazard areas that may be available from the United States Geological Survey. Fire § 65302 g.3.A.iv.

General location and distribution of existing and planned uses of land in very high fire hazard severity zones and in state responsibility areas, including structures, roads, utilities, and essential public facilities. The location and distribution of planned uses of land shall not require defensible space compliance measures required by state law or local ordinance to occur on publicly owned lands or open space designations of homeowner associations.

Fire
§ 65302 g.3.A.v. Local, state, and federal agencies with responsibility for fire protection, including special districts and local offices of emergency services. Fire
§ 65302 g.3.B. Fire
§ 65302 g.3.C. Fire
§ 65302 g.3.C.i. Avoiding or minimizing the wildfire hazards associated with new uses of land. Fire § 65302 g.3.C.ii.

Locating, when feasible, new essential public facilities outside of high fire risk areas, including, but not limited to, hospitals and health care facilities, emergency shelters, emergency command centers, and emergency communications facilities, or identifying construction methods or other methods to minimize damage if these facilities are located in a state responsibility area or very high fire hazard severity zone.

Fire
§ 65302 g.3.C.iii.

Designing adequate infrastructure if a new development is located in a state responsibility area or in a very high fire hazard severity zone, including safe access for emergency response vehicles, visible street signs, and water supplies for structural fire suppression.

Fire
§ 65302 g.3.C.iv. Working cooperatively with public agencies with responsibility for fire protection. Fire Include information regarding fire hazards, including, but not limited to:

Include a set of comprehensive goals, policies, and objectives based on fire hazard information for the protection of the community from the unreasonable risk of wildfire.

A set of feasible implementation strategies to carry out the goals, policies, and objectives for the protection of the community from the unreasonable risk of wildfire.

Establish a set of comprehensive goals, policies, and objectives based on flood hazard information for the protection of the community from the unreasonable risks of flooding, including but not limited to:

Establish a set of feasible implementation strategies to carry out the goals, policies, and objectives established for the protection of the community from the unreasonable risks of flooding.

Address the risk of fire for land classified as state responsibility areas, as defined in Section 4102 of the Public Resources Code, and land classified as very high fire hazard severity zones, as defined in Section 51177. Consider the advice included in the Office of Planning and Research’s most recent publication of “Fire Hazard Planning, General Plan Technical Advice Series.”

§ 65302 g.4.

If a city or county has adopted the local hazard mitigation plan, or other climate adaptation plan or document that fulfills commensurate goals and objectives and contains the information required pursuant to this paragraph, separate from the general plan, an attachment of, or reference to, the local hazard mitigation plan or other climate adaptation plan or document.

Cities or counties that have an adopted hazard mitigation plan, or other climate adaptation plan or document that substantially complies with this section, or have substantially equivalent provisions to this subdivision in their general plans, may use that information in the safety element to comply with this subdivision, and shall summarize and incorporate by reference into the safety element the other general plan provisions, climate adaptation plan or document, specifically showing how each requirement of this subdivision has been met.

Adaptation OPR General Plan Guidelines
SB-379 (2015) Vulnerability
Assessment and Hazard
Mitigation Plan in Safety
Element
§ 65302 g.4.A. Adaptation Cal-Adapt, 2020 California
Adaptation Planning Guide
§ 65302 g.4.B. Adaptation
§ 65302 g.4.C. Adaptation
§ 65302 g.4.C.i. Feasible methods to avoid or minimize climate change impacts associated with new uses of land. Adaptation § 65302 g.4.C.ii.

The location, when feasible, of new essential public facilities outside of at-risk areas, including, but not limited to, hospitals and health care facilities, emergency shelters, emergency command centers, and emergency communications facilities, or identifying construction methods or other methods to minimize damage if these facilities are located in at-risk areas.

Adaptation
§ 65302 g.4.C.iii. The designation of adequate and feasible infrastructure located in an at-risk area. Adaptation § 65302 g.4.C.iv. Guidelines for working cooperatively with relevant local, regional, state, and federal agencies. Adaptation § 65302 g.4.C.v.

The identification of natural infrastructure that may be used in adaptation projects, where feasible.

Where feasible, the plan shall use existing natural features and ecosystem processes, or the restoration of natural features and ecosystem processes, when developing alternatives for consideration. For purposes of this clause, “natural infrastructure” means using natural ecological systems or processes to reduce vulnerability to climate change related hazards, or other related climate change effects, while increasing the long-term adaptive capacity of coastal and inland areas by perpetuating or restoring ecosystem services. This includes, but is not limited to, the conservation, preservation, or sustainable management of any form of aquatic or terrestrial vegetated open space, such as beaches, dunes, tidal marshes, reefs, seagrass, parks, rain gardens, and urban tree canopies. It also includes systems and practices that use or mimic natural processes, such as permeable pavements, bioswales, and other engineered systems, such as levees that are combined with restored natural systems, to provide clean water, conserve ecosystem values and functions, and provide a wide array of benefits to people and wildlife.

Adaptation
§ 65302 g.5. Upon the next revision of the housing element on or after January 1, 2020. Evacuation
SB-99 (2019) General
Plans/Safety
Element/Emergency
Evacuation
§ 65302 g.6. Upon each revision of the housing element or local hazard mitigation plan, but not less than once every eight years. Adaptation SB-1035 (2018) General Plans § 65302 h.1.

A city, county, or city and county subject to this subdivision shall adopt or review the environmental justice element, or the environmental justice goals, policies, and objectives in other elements, upon the adoption or next revision of two or more elements concurrently on or after January 1, 2018.

General Plan Guidelines
Chapter 4: Environmental
Justice Element
SB-1000 (2016)
Environmental Justice
Requirements in General Plan
§ 65302 h.1.A. Environmental
Justice
§ 65302 h.1.B. Environmental
Justice
§ 65302 h.1.C. Environmental
Justice
Identify objectives and policies that prioritize improvements and programs that address the needs of disadvantaged communities.

Include a set of feasible implementation measures designed to carry out the goals, policies, and objectives identified for the protection of the community.

Identify residential developments in any hazard area identified in the safety element that do not have at least two emergency evacuation routes
Review and, if necessary, revise the safety element to identify new information relating to flood and fire hazards and climate adaptation and resiliency strategies applicable to the city or

ENVIRONMENTAL JUSTICE ELEMENT
An environmental justice element, or related goals, policies, and objectives integrated in other elements, that identifies disadvantaged communities within the area covered by the general plan of the city, county, or city and county, if the city, county, or city and county has a disadvantaged community. "Disadvantaged community" - low-income area that is disproportionately affected by environmental Identify objectives and policies to reduce the unique or compounded health risks in disadvantaged communities by means that include, but are not limited to, the reduction of pollution exposure, including Identify objectives and policies to promote civic engagement in the public decisionmaking process.

Address climate adaptation and resiliency strategies applicable to the city or county. Consider advice provided in the Office of Planning and Research’s General Plan Guidelines.

Include a vulnerability assessment that identifies the risks that climate change poses to the local jurisdiction and the geographic areas at risk from climate change impacts.

Include a set of adaptation and resilience goals, policies, and objectives based on the information specified in the vulnerability assessment for the protection of the community.

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.1
G.1 Community Profile
G.1.1 Mitigation Planning History and 2019 Process
Annex G, City of San Luis Obispo ( City), was created during the development of the 2019 Multi- Jurisdictional San Luis Obispo Hazard Mitigation Plan update (HMP). This Jurisdictional Annex builds upon and supersedes the 2014 City of San Luis Obispo Local Hazard Mitigation Plan (LHMP). The 2014 Plan was not integrated into the City’ s Land Use Element; that integration will be done after the approval of this updated Plan. The General Plan Safety Element references the 2014 Local Hazard Mitigation Plan in Chapter 5:

Additional information on hazards in the San Luis Obispo area can be found in the Technical Background Report for the San Luis Obispo County and Cities Safety Element (June 1999). Additionally, the City of San Luis Obispo Local Hazard Mitigation Plan presents a comprehensive risk assessment of natural hazards that have the potential to affect the City of San Luis Obispo. The Local Hazard Mitigation Plan was developed by the City in accordance with the Federal Disaster Mitigation Act of 2000, adopted by the City Council and approved by the Federal Emergency Management Agency. The Local Hazard Mitigation Plan suggests possible mitigation actions for reducing the effects of potential hazards. It is incorporated by reference into the Safety Element and should be consulted when addressing known hazards to ensure the general health and safety of people within the City of San Luis Obispo. The goals and policies within this Safety Element support and are consistent with the recommended mitigation strategy within the Local Hazard Mitigation Plan.

The City had representation on the County multi-jurisdictional Hazard Mitigation Planning Committee and utilized a Local Planning Team (LPT) subcommittee to develop input into the annex.

Table G.1 City of San Luis Obispo Local Planning Team
Department or Stakeholder Title
Fire Department Fire Chief
Fire Department Fire Marshall
Fire Department Administrative Analyst
Administration Natural Resources Manager
Administration Sustainability Manager
More details on the planning process and participating jurisdictions, service districts and stakeholders can be found in Section 3 of the Base Plan, along with the public’s role during the 2019 update.

G.1.2 Geography and Climate
The City is located in California’s Central Coast region approximately 200 miles north of Los Angeles and 230 miles south of San Francisco. The City is situated to the west of the Santa Lucia Mountains and is located eight miles east of the Pacific Ocean. The San Luis Obispo Creek originates from the mountains and flows westward in confluence with the Pacific Ocean at Avila Beach. The mountain ranges form a natural barrier to development in San Luis Obispo. The City is an estimated 10.7 square miles and is surrounded by protected open space and productive agricultural lands. San Luis Obispo is regionally accessible via US Highway 1, US Highway 101, and State Route 227 (Broad Street). The City terrain stands at an average elevation of 300 feet above sea level, with prominent peaks such as Cerro San Luis and Bishop Peak at 1,292 and 1,559 feet, respectively, above sea level.

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.2
The City’s Sphere of Influence includes approximately 5,930+/- acres outside of the City limits and includes nine unincorporated areas: Cal Poly, Florita-Alrita, Orcutt, Broad Street, Airport, Chevron, Los Osos Valley Road/US Highway 101, San Luis Ranch, and Cerro San Luis area. All lands outside of the City’s Sphere of Influence are regulated by the San Luis Obispo County General Plan and zoning designations. State law requires that cities maintain plans for areas outside of their immediate jurisdiction if the areas have a direct relationship to planning needs.

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.3
Figure G.1 The City of San Luis Obispo

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.4
San Luis Obispo is characterized by a Mediterranean climate with an average temperature of 70.2 degrees Fahrenheit. While generally considered a mild climate, weather patterns and events have historically observed both unseasonably warm periods and cold spells. The City receives an average precipitation of 19 inches per year, with increased amounts of rainfall in the winter and spring months between November and April (US Climate Data 2019). Due to its close proximity to the Pacific Ocean, San Luis Obispo is also subject to coastal weather influences such as dense fog that typically rolls into the City through the Chorro Valley, steady on- shore wind patterns, and coastal storms. For general details on climate characteristics of the region refer to the Adverse Weather Section of the Risk Assessment in the HMP (Section 5.3.1).

G.1.3 History
The native Chumash Tribe was the first known settled human population in the City of San Luis Obispo area. The Chumash established a network of villages along the San Luis Obispo Creek. Spanish Colonization of the area began in 1769 with the founding of Mission San Luis Obispo de Tolosa in 1772 by Father Junipero Serra , resulting in devastating impacts to the Chumash culture. Diseases and significant alterations of culture due to the establishment of the mission caused a significant decrease in the Native American population. Spanish and Mexican ranchos were established in the area in the late 1700s. The development of the area of San Luis Obispo has historically been connected to the San Luis Obispo Creek, where the first settlements could be found, and to the emphasis on agricultural production by the Mission and later the adjacent ranchos.

The California Land Act of 1851 caused a shift to residential development in San Luis Obispo. By 1870, the community had grown to a population of 1,579 and it became a charter city in 1876. Historic influences on the growth and development of San Luis Obispo include the City’ s beginnings as a center for agricultural productivity, the extension of the Southern Pacific Railroad in 1894, and the establishment of California Polytechnic State University (Cal Poly) in 1901.

Agriculture, transportation, government, and education related activities continue to play a significant role in the demographic, economic, land use, and development characteristics of the City. These characteristics and proactive protection of the City’s natural and scenic resources contribute to the small-town charm and high quality of life of the City’s residents.

G.1.4 Economy
As the civic, economic, and cultural hub of the Central Coast, the City serves as the seat of the County of San Luis Obispo. With major regional employers such as Cal Poly, state agencies, PG& E, Tenet Health Care, and the County of San Luis Obispo, the City has an estimated daytime population of more than 70,000 people. The San Luis Obispo Chamber of Commerce and the Downtown Association are active collaborators and leaders in supporting the retention and expansion of local businesses in the City. The City’s leading industries include hospitality, food services, retail, professional services, health care, information and technology, public administration, and educational sectors.

To support the high quality of life and economic vitality of the community, San Luis Obispo is considered a fullservice city, providing police, fire, water, sewer, streets, transit, parking, planning, building, engineering, and parks and recreation services to the community.

Select estimates of economic characteristics for the City of San Luis Obispo are shown in Table G.2.

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.5
Table G.2 City of San Luis Obispo Economic Characteristics, 2017 Characteristic City of San Luis Obispo
Families below Poverty Level 6.9%
All People below Poverty Level 32.4%
Median Family Income $ 87,635
Median Household Income $ 49,640
Per Capita Income $ 29,748
Population in Labor Force 25,363
Population Employed* 41,668
Unemployment 1,128
Source: U.S. Census Bureau American Community Survey 2017, www. census. gov/ Excludes armed forces
Table G.3 and Table G.4 show the occupational and industry breakdown of the City of San Luis Obispo’s labor force based on estimates from the 2017 American Community Survey.

Table G.3 City of San Luis Obispo’s Employment by Occupation, 2017 Occupation # Employed % Employed
Sales and Office Occupations 5,630 21.6%
Management, Business, Science, and Arts Occupations 10,777 44.5% Natural Resources, Construction, and Maintenance Occupations 934 3.9% Production, Transportation, and Material Moving Occupations 1,632 6.7% Service Occupations 5,240 21.6%
Total 24,213
Source: U.S. Census Bureau American Community Survey 2017, www. census. gov/ Excludes armed forces
Table G.4 City of San Luis Obispo’s Employment by Industry, 2017 Industry # Employed % Employed
Retail Trade 3,044 12.6%
Professional, Scientific, and Mgmt., and Administrative and Waste Mgmt. Services 2,879 11.9% Manufacturing 1,585 6.5%
Arts, Entertainment, and Recreation, and Accommodation, and Food Services 4,292 17.7% Construction 886 3.7%
Finance and Insurance, and Real Estate and Rental and Leasing 846 3.5% Public Administration 948 3.9%
Other Services, Except Public Administration 1,281 5.3% Wholesale Trade 509 2.1%
Transportation and Warehousing, and Utilities 731 3.0%
Agriculture, Forestry, Fishing and Hunting, and Mining 269 1.1% Information 457 1.9%
Educational Services, and Health Care, and Social Assistance 6,486 26.8% Total 24,213
Source: U.S. Census Bureau American Community Survey 2017, www. census. gov/

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.6
G.1.5 Population
In May 2019, the State Department of Finance released preliminary population data for the state to reflect wildfire-driven changes to local populations. The City of San Luis Obispo has a population of 46,802 persons as of January 2019, which accounts for approximately 16.7% of the County’s population. The City experienced a growth of 0.1% from 46,741 residents from January 2018 ( Department of Finance 2019). The U.S. Census Bureau’s American Community Survey 2017 5-Year Estimates provide select demographic and social characteristics and changes from 2012 to 2017 for the City of San Luis Obispo ( Table G.5).

Table G.5 City of San Luis Obispo’ s Demographic and Social Characteristics, 2012 to 2017 Characteristic 2012 2017
Population 270,121 280,119
Median Age 39.3 39.0
Total Housing Units 117,318 120,182
Housing Occupancy Rate 86.7% 87.4%
of Housing Units with no Vehicles Available 4.5% 4.5%
Median Home Value $ 449,300 $ 499,800
Unemployment 8.7% 4.8%
Mean Travel Time to Work ( minutes) 20.9 21.8
Median Household Income $ 59,628 $ 67,175
Per Capita Income $ 30,218 $ 33,972
of Individuals Below Poverty Level 13.7% 13.8%
of Households 101,708 105,044
Average Household Size 2.49 2.51
of Population Over 25 with High School Diploma 89.5% 90.5% of Population Over 25 with Bachelor’ s Degree or Higher 31.5% 34.0% with Disability 11.1% 11.1%
Speak English less than "Very Well" 6.7% 6.8%
Source: U.S. Census Bureau American Community Survey 2017 5-Year Estimates, www.census. gov/ Between 1950 and 1990, the City grew from a population of 14,180 to just under 42,000. Since 1990, the City has maintained an average growth rate of less than one percent per year. Owner -occupied housing units account for 39% of all households, while approximately 61% of households are renter -occupied. The City’s population is growing steadily at a relatively slow rate at approximately 1% or less per year with an estimated of 5.3% growth since the 2010 Census. The SLO 2035 Land Use and Circulation Elements update provides population estimates

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.7
Table G.6 City of San Luis Obispo Population Growth
Year Approximate Maximum
Number of Housing Units
Projected
Population
2013 20,697 45,541
2015 21,113 46,456
2020 22,190 48,826
2025 23,322 51,317
2030 24,512 53,934
2035 25,762 56,686
Source: SLO 2035 Land Use Element Update
G.1.6 Development Trends
The City has traditionally expanded through annexation of County lands and increased development of diverse land uses; these include low to high density residential, general retail and commercial, services, and manufacturing uses bordering the San Luis Obispo Regional Airport , and dispersed undeveloped open space.

With Mission Plaza and downtown at the heart of the City, development trends have included transition from the historic neighborhoods immediately adjacent to Downtown, to post-World War II growth in areas along the foothills of the Santa Lucia Mountains, surrounding Laguna Lake, and in the northern areas of town near the growing Cal Poly. Recent development efforts have focused on incorporating additional housing opportunities in the historic downtown core, through the renovation of historic structures and infill development on underutilized and vacant land. The Land Use Element of the City’ s General Plan provides designated land use and establishes development standards for new and existing structures and uses. The Safety Element further identifies hazards that may influence the locations and types of proposed land uses and provides policies that reduce exposure to hazards. These policies have also encouraged changes to development in San Luis Obispo’s hazard prone/vulnerable areas, decreasing the City’s vulnerability. Any future development within the City will be informed by the most up to date hazard maps as well as state and local development ordinances (e.g. floodplain) that restrict development in hazard prone areas to minimize risk.

In recent years, more residents and visitors are staying and living in the downtown core. This change in demographic could impact response capabilities if a hazard impacts the downtown core. The City also has a greenbelt protection program and have acquired thousands of acres of land around the City to minimalize development in areas around the City. Thus, the redevelopment of already developed areas or infill development is likely to be the trend in the future.

Specific to hazards, continuing moderate population growth is increasing exposure to earthquake hazards, though new or re-developed areas built to modern codes will be more resistant to collapse and damage.

G.2 Hazard Identification and Summary
San Luis Obispo’s planning team identified the hazards that affect the region and summarized their frequency of occurrence, spatial extent, potential magnitude, and significance specific to the City (see Table G.7). There are no hazards that are unique to the City. The overall hazard significance takes into account the geographic area, probability and magnitude as a way to identify priority hazards for mitigation purposes. This is discussed further in the Vulnerability Section (4.3).

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.8
Table G.7 City of San Luis Obispo – Hazard Summaries
Hazard Geographic
Area
Probability of
Future
Occurrence
Magnitude/
Severity ( Extent)
Overall
Significance
Adverse Weather: Thunderstorm/
Heavy Rain/ Hail/ Lightning/ Dense
Fog/ Freeze
Extensive Likely Limited Medium
Adverse Weather: High Wind/
Tornado
Extensive Occasional Limited Medium
Adverse Weather: Extreme Heat Extensive Occasional Negligible Low Agricultural Pest Infestation and
Disease Limited Highly Likely Negligible Medium
Biological Agents Extensive Occasional Critical Medium
Drought and Water Shortage Extensive Likely Limited Medium Earthquake Extensive Occasional Catastrophic High
Flood Limited Occasional Limited Medium
Landslides and Debris Flow Limited Occasional Limited Low Subsidence Significant Occasional Negligible Low
Wildfire Significant Occasional Limited Medium
Human Caused: Hazardous Materials Significant Highly Likely Negligible Medium Geographic Area
Limited: Less than 10% of planning area
Significant: 10-50% of planning area
Extensive: 50-100% of planning area
Probability of Future Occurrences
Highly Likely: Near 100% chance of occurrence in next
year or happens every year.

Likely: Between 10- 100% chance of occurrence in next
year or has a recurrence interval of 10 years or less.

Occasional: Between 1 and 10% chance of occurrence
in the next year or has a recurrence interval of 11 to
100 years.

Unlikely: Less than 1% chance of occurrence in next
100 years or has a recurrence interval of greater than
every 100 years.

Magnitude/ Severity ( Extent)
Catastrophic—More than 50 percent of property severely
damaged; shutdown of facilities for more than 30 days; and/or multiple deaths
Critical— 25- 50 percent of property severely damaged; shutdown of facilities for at least two weeks; and/ or injuries and/ or illnesses result in permanent disability
Limited— 10- 25 percent of property severely damaged; shutdown of facilities for more than a week; and/ or injuries/ illnesses treatable do not result in permanent disability
Negligible— Less than 10 percent of property severely damaged, shutdown of facilities and services for less than 24 hours; and/ or injuries/illnesses treatable with first aid
Significance
Low: minimal potential impact
Medium: moderate potential impact
High: widespread potential impact

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.9
G.3 Vulnerability Assessment
The intent of this section is to assess the City’s vulnerability separately from that of the County as a whole, which has already been assessed in Chapter 5 of the Base Plan. This vulnerability assessment analyzes the population, property, and other assets at risk to hazards ranked of medium or high significance specific to the City.

The information to support the hazard identification and risk assessment was based on a combination of the pervious previous LHMP for the City and jurisdiction specific information collected during the 2019 update. A Local Hazard Mitigation Plan Update Guide and associated worksheets were distributed to each participating municipality or special district to complete during the 2019 update process. Information collected was analyzed and summarized in order to identify and rank all the hazards within the County , as well as to rank the hazards and identify the related vulnerabilities unique to each jurisdiction.

Each participating jurisdiction was in support of the main hazard summary identified in the Base Plan (See Table

5.2). However, the hazard summary rankings for each jurisdictional annex may vary slightly due to specific hazard risk and vulnerabilities unique to each jurisdiction (See Table G.7).

Note: The hazard “Significance” reflects overall ranking for each hazard and is based on the City of San Luis Obispo LPT member input from the Data Collection Guide and the risk assessment developed during the planning process (see Chapter 5 of the Base Plan), which included a more detailed qualitative analysis with best available data.

The hazard summaries in Table G.7 reflect the hazards that could potentially affect City. The discussion of vulnerability for each of the following hazards is located in Section G.3.2 Estimating Potential Losses. Based on this analysis, the highest priority hazard (High Significance) for mitigation is Earthquake. Those of Medium or High significance for the City of San Luis Obispo are identified below.

Adverse Weather: Thunderstorm/Heavy Rain/Hail/Lighting/Dense Fog/Freeze Adverse Weather: High Wind/Tornado
Agricultural Pest Infestation and Disease
Biological Agents
Drought and Water Storage
Earthquake
Flood
Human Caused: Hazardous Materials
Wildfire
Other Hazards
Hazards assigned a significance rating of Low and which do not differ significantly from the County ranking (e.g., Low vs. High) are not addressed further in this plan. In the City of San Luis Obispo, those hazards are:

Landslide and Debris Flow
Adverse Weather: Extreme Heat
Subsidence
Additionally, the City’s HMPC members decided to rate several hazards as Not Applicable (N/A) to the planning area due to a lack of exposure, vulnerability, and no probability of occurrence. Dam Incidents, Coastal

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.10
Storm/Coastal Erosion/Sea Level Rise, and Tsunami and Seiche Hazards are considered Not Applicable (N/A) to the City of San Luis Obispo.

G.3.1 Assets at Risk
This section considers San Luis Obispo’ s assets at risk, including values at risk, critical facilities and infrastructure, historic assets, economic assets, and growth and development trends. The HMPC used a variety of data to define a baseline against which all disaster impacts could be compared. If a catastrophic disaster was to occur in the Planning Area, this section describes significant assets exposed or at risk in the City of San Luis Obispo.

Values at Risk
Parcel data was provided by ParcelQuest, a third- party service working alongside the San Luis Obispo County Assessor’s Office to compile property information. This data provided the baseline for an inventory of the total exposure of developed properties within the county and helps to ensure that the updated HMP reflects changes in development. This data should only be used as a guideline to overall values in the City as the information has some limitations. The most significant limitation is created by Proposition 13; instead of adjusting property values annually, the values are not adjusted or assessed at fair market value until a property transfer occurs. As a result, overall value information is likely low and does not reflect current market value of properties. It is also important to note that in the event of a disaster, it is generally the value of the infrastructure or improvements to the land that is of concern or at risk. Generally, the land itself is not a loss. Table G.8 shows the exposure of properties ( e.g., the values at risk) broken down by property type for the City of San Luis Obispo.

Table G.8 2019 Property Exposure for the City of San Luis Obispo by Property Types Property Type Property
Count
Improved
Value Content Value Total
Value
Commercial 1,081 $ 1,023,078,842 $ 1,023,078,842 $ 2,046,157,684 Government/ Utilities 168 $ 1,435,945 -- $ 1,435,945
Other/Exempt/Misc. 507 $ 189,186,968 -- $ 189,186,968
Residential 8,226 $ 1,896,071,588 $ 948,035,794 $ 2,844,107,382 Multi- Family Residential 2,885 $ 811,851,931 $ 405,925,966 $ 1,217,777,897 Mobile/ Manufactured
Homes
156 $ 25,110,344 $ 12,555,172 $ 37,665,516
Residential: Other 963 $ 368,632,456 $ 184,316,228 $ 552,948,684 Industrial 42 $ 60,310,187 $ 90,465,281 $ 150,775,468
Vacant 55 $ 36,862,009 -- $ 36,862,009
Total 14,083 $ 4,412, 540,270 $ 2,664, 377,282 $ 7,076, 917,552 Source: Wood analysis based on ParcelQuest and San Luis Obispo County Assessor’ s Office data 2019.

Critical Facilities and Infrastructure
Critical Facilities are essential in providing utility or direction either during the response to an emergency or during the recovery operation. These facilities typically include hospitals, fire stations, and local law enforcement stations, and according to FEMA should be given special consideration when formulating regulatory hazard

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.11
mitigation and floodplain management plans. See Section 5.2 of the Base Plan for more details on the definition s and categories of critical facilities.

A portion of the critical facilities data was provided by the San Luis Obispo County Planning & Building and GIS Departments. Supplemental data from the Homeland Infrastructure Foundation -Level Data (HIFLD) was used to capture additional facilities such as law enforcement facilities and centers, communications facilities, emergency operations centers, schools, and urgent care facilities among others. In addition, participating jurisdictions identified assets on a data collection guide worksheet or in previous LHMPs which may capture additional facilities and additional details not within the GIS database. An inventory of critical facilities in the City of San Luis Obispo determined with San Luis Obispo County GIS data is provided in Table G.9 and illustrated in Figure G.2.

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.12
Figure G.2 Critical Facilities in the City of San Luis Obispo

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.13
Table G.9 City of San Luis Obispo’s Critical Facilities Category Asset Name Asset IDs Address Replacement
Value Priority
Community and
Recreational
Facilities
City Hall 68 990 Palm St $ 9,287,080 Critical
Library 451 995 Palm St $ 1,604,146 Essential
Ludwick Community Center 452 864 Santa Rosa St $ 2,559,501 Critical Meadow Park Recreational
Center 453 2333 Meadow St $ 1,448,126 Essential
Mitchell Park Senior Center 456 1445 Santa Rosa St $ 1,068,158 Essential Sinsheimer Pool and Park 97- 110 900 Southwood Dr $ 2,623,419 Essential Infrastructure
Critical Bridges
10, 11, 19, 20,
23, 25, 27, 34,
35, 40, 41, 42,
44, 51, 56
Varies by bridge Varies by
bridge Critical
Essential Bridges
8, 9, 12-18, 21,
22, 24, 26, 28-
33, 36-39, 43,
45-50, 52-55,
58, 59-62
Varies by bridge Varies by
bridge Essential
Higuera Box Culvert 57 Higuera St $ 4,500,000 Critical
Evacuation Route Roads 50 miles $ 1 million/ mile
50,000,000 Critical
Other Essential City- Owned
Roads 120 miles
1 million/ mile
120,000,000
Essential
Communication Towers 614,616,617 N/ A Essential
Other City-Owned
Facilities
City Corporation Yard 426 25 Prado Rd $ 4,884,929 Critical Community Development and
Public Works Administration 437 919 Palm St $ 23,081,375 Essential Parking Garage 477 Marsh and Chorro
St $ 22,873,449 Essential
Parking Garage 478 842 Palm St $ 8,795,686 Essential
Parks and Recreation Building 479 1341 Nipomo St $ 1,282,662 Essential Prado Day Center 96 45 Prado Rd $ 699,393 Essential
Utilities Administration 541 879 Morro St $ 1,060,252 Essential Police and Fire
Stations
Dispatch Center 78 1135 Roundhouse $ 6,701,098 Critical Fire Station #1 69 2160 Santa Barbara $ 5,483,205 Critical Fire Station #2 70 136 N Chorro St $ 511,872 Critical
Fire Station # 3 71 1280 Laurel Ln $ 594,009 Critical
Fire Station # 4 72 1395 Madonna Rd $ 507,087 Critical
Police Main Building, Garage,
Annex 73- 77 1042 and 1016Walnut St $ 4,854341 Critical Potable Water
and Wastewater
Facilities
Fire Station # 4 Well 619 1395 Madonna Rd N/ A Essential Pacific Beach Well 620 11950 LOVR N/A Essential
Reservoirs 63-67 N/A Essential
Sewer Lift Stations 555-564 N/A Essential
Sewer System Infrastructure
pipes) N/ A Essential
Storm Drain System N/ A Essential

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.14
Category Asset Name Asset IDs Address Replacement
Value Priority
Waste Water Treatment Plant
includes Water/Wastewater
Laboratory)
615 35 Prado Rd $ 77,296,765 Essential
Water Pump Stations 1-7 N/ A Critical
Water System Infrastructure
pipes) N/ A Critical
Water Tanks 566- 613 N/ A Critical
Water Treatment Plant and
Stenner Hydro Plant 565 Stenner Creek Rd $ 51,486,423 Essential Source: San Luis Obispo County Planning & Building, HIFLD High Potential Loss Facilities
High potential loss facilities are considered critical facilities that present significant risks if damaged and include nuclear power plants, dams, and military installations. The City has one classified high potential loss facility: The San Luis Obispo Wastewater Treatment Plant (WWTP). The WWTP is located within a 100-year floodplain and within a moderate liquefaction risk zone; however, other potential hazard impacts are low.

Transportation and Lifeline Facilities
The City contains a network of roadways and public transportation including the Pacific Coast Railway . US Highway 101, Highway 1, and State Route 227 (Broad Street) provide regional access to the City. The San Luis Obispo County Regional Airport serves the City and is located in the southern portion of the jurisdiction.

Lifeline Utility Systems are defined as those systems necessary to provide electric power, natural gas, water and wastewater, and other facilities and services that are essential to the well -being of the City. Lifeline utility systems within the City include:

AM Transmission Towers (1)
FM Transmission Towers ( 1)
Microwave Service Towers (52)
Wastewater Treatment Plants ( 1)
Energy Commission Facilities (7)
Historic and Cultural Resources
The City of San Luis Obispo has a wealth of historic and culturally significant resources due to its rich and varied history. Such resources represent the City’s diverse historical context from periods prior to Chumash settlement and Spanish colonization, through early development and mid-century growth that established many of the existing neighborhoods and set a precedent for community design. The City of San Luis Obispo Citywide Historic Context Statement (2014) identifies various historical factors that shaped the development of the area, and provides a framework for the continuing process of identifying historic, architectural, and cultural resources in the City. The City has an active historic preservation program, and historic preservation is prioritized throughout City policy. City Zoning Regulations also establish the Historical Preservation Overlay Zone, which describes the allowed uses and property development standards within designated Historic Districts. Historic Districts within the City include Downtown Commercial District, the Mill Street District, the Old Town Neighborhood, the Little

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.15
Italy District, the Monterey Heights District, the Mount Pleasanton/Anholm District, the Chinatown Historic District, and the Railroad Districts.

Historical resources in the context of the City are also identified by the National Register of Historic Places NRHP), the California Register of Historic Resources (CRHR), and the County of San Luis Obispo’s List of Historic Resources in addition to local designation. Such resources are buildings, structures, objects, places, and areas that have an association with important persons, events in history, or cultural heritage, or have distinctive architecture, design or construction method. State and local registers of historic resources also identify Historical Points of Interest that have primarily local significance and interest in preservation. The City of San Luis Obispo has several registered national, state, and local sites of historic and cultural significance (Table G.10). Countywide historic resources are further detailed in Chapter 5.2, Asset Summary, of the Base Plan.

Table G.10 Historic Places
Historic Site Register Date Listed Address
Ah Louis Store State/National 1965 800 Palm Street
Angel Myron House National 1982 714 Buchon St.

Corral de Piedra National 1978 S of San Luis Obispo on Price Canyon Rd.

Dallidet Adobe State 1960 1185 Pacific Street
Jack Robert House National 1992 536 Marsh St.

Mission San Luis Obispo De
Tolosa
State 1939 751 Palm Street
Monday Club of San Luis Obispo National 2016 1815 Monterey St.

Pacific Coast Railway Company
Grain Warehouse National 1988 65 Higuera St.

Pereira Octagon Barn National 2014 4400 Octagon Way
Port San Luis Site National 1978 Address Restricted
The Powerhouse National 1993
Junction of S/ Perimeter Rd. and
Cuesta Ave
Rancho Canada de los Osos y
Pecho y Islay
National 1975 Address Restricted
San Luis Obispo Carnegie Library National 1995 696 Monterey St.

Tribune Republic Building National 1993 1763 Santa Barbara St.

William Shipsey House National 2010 1266 Mill St.

Camp San Luis Obispo State Point of
Interest
1990 NA
Hollister Adobe State Point of
Interest 1972 NA

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.16
Natural Resources
Natural resources are important to include in benefit-cost analyses for future projects and may be used to leverage additional funding for projects that also contribute to community goals for protecting sensitive natural resources. Awareness of natural assets can lead to opportunities for meeting multiple objectives. For instance, protecting wetlands areas protects sensitive habitat as well as attenuates and stores floodwaters.

The City’ s landscape is made up of creeks, hills, valleys, and rich farmland that supports a variety of plants and animal species. The San Luis Obispo area contains a diverse array of naturally occurring biological communities and extensive open space areas including the Irish Hills Natural Reserve, the Islay Hills Open Space, South Hills Open Space, Charles A. and Mary R. Maino Open Space, Ferrini Ranch, and the Laguna Lake Park and Open Space. The City’s many creeks provide sheltered corridors that allow wildlife to move between dispersed habitats and open space areas.

Economic Assets
California Polytechnic State University is the largest employer in the City of San Luis Obispo with nearly 3,000 employees. San Luis Coastal Unified School District employs 384 regular classified employees. The industrial sector including education services, healthcare, and social assistance are the largest employers in the City at approximately 20.2% of the total employers. In 2007, approximately 5,127 individuals were employed in educational services, health care, and social assistance jobs. The General Plan Land Use Element (LUE) for the City includes policies to accommodate a maximum population of 57,200 persons. Assuming a 0.5% growth rate, the City would reach the anticipated residential capacity by year 2057. Tourism is an increasing trend in the City due to the diverse range of activities, small-town appeal and recent development of several hotels near and in the downtown core. Loss of a major employer from a hazard impact would result in a significant rise in unemployment and loss in sales tax revenue.

G.3.2 Estimating Potential Losses
Note: This section details vulnerability to specific hazards of high or medium significance, where quantifiable, and/or where (according to HMPC member input) it differs from that of the overall County.

Table G.9 above shows San Luis Obispo’s exposure to hazards in terms of number and value of structures. San Luis Obispo County parcel and assessor data were used to calculate the improved value of parcels. The most vulnerable structures are those in the floodplain ( especially those that have been flooded in the past), unreinforced masonry buildings, and buildings built prior to the introduction of modern-day building codes.

Impacts of past events and vulnerability to specific hazards are further discussed below . (See Section 4.1 Hazard Identification for more detailed information about these hazards and their impacts on the County as a whole.) Adverse Weather: Thunderstorm/ Heavy Rain/ Hail/ Lightning/ Dense Fog/ Freeze Adverse weather in the City usually occurs as localized thunderstorms that bring heavy rains and strong winds, most often during the winter and spring months. Heavy rain has historically produced extensive flooding in the City. Dense fog can result in reduced visibility and slick road conditions that increase the likelihood for traffic accidents. Freeze is rarely a threat to human life in the City, but has the potential to impact agricultural operations where crop damage to high value products can be extensive. According to frost dates and temperature data published by the University of California Agriculture & Natural Resources, the lowest recorded temperature is 20 F, and average annual low temperatures of 42 to 43 F typically occur in January and December.

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.17
Adverse Weather: High Wind/Tornado
The City is subject to strong southeasterly winds associated with strong cold fronts and coastal storms, which generally occur during the winter months from November to February. Northwesterly winds that are typical of the central coast of California also occur throughout San Luis Obispo during the spring and summer. Both southeast and northwest wind events can reach sustained wind speeds of 35- 45 mph with wind gusts of 65- 75 mph within the City. Wind related events can have substantial destructive impacts, especially in urban areas where falling trees and branches can result in considerable property damage. Tornadoes have historically occurred in San Luis Obispo, with the first recorded tornado taking place in April 1926 due to a strong coastal storm front from the Pacific. Recorded tornadoes since then have typically been low severity, and caused minor damage such as broken tree branches and minor structural and roof damage to buildings. Refer to Section 5.3.1 Adverse Weather, in the Base Plan for analysis related to tree mortality in the County of San Luis Obispo.

Agricultural Pest Infestation and Disease
Agricultural pests and pathogens (insects, fungi, bacteria, viruses and invasive plants) cause injury or destruction to crops or livestock. The prominent agricultural uses in San Luis Obispo County can be impacted by a wide variety of invasive pests, which pose a significant threat to crops, economy, food supply, and native habitat.

Biological Agents
Public health impacts due to biological agents are a recognized potential threat to the City. The City is largely reliant on the County’ s Emergency Preparedness Program, which supports the Public Health Departm ent in the management and coordination of public health emergencies including natural disasters, technological disasters, bioterrorism incidents, and pandemics. Food and waterborne illnesses are major health problems that present significant health risks to the City as well as threats to regional food and water supply. The City supports and participates in the County Public Health Department’s up-to-date Pandemic Influenza Plan and Strategic National Stockpile Plan to facilitate prevention, early detection, and treatment to effectively respond to pandemics.

Drought and Water Storage
Periods of drought can have significant environmental, agricultural, health, economic, and social consequences.

Prolonged drought has the potential to impact structures due to subsidence, and can reduce water quality due to lower water flows and reduced pollutant dilution. The City recently experienced its third driest period on record since 1870 when weather observations began at the San Luis Obispo Polytech Weather Station. Long - term precipitation information from the station indicates the variability that can occur, which is summarized in Figure 5-4 in Section 5.3.6 of the Base Plan. The City has invested in a multi-source water supply including Nacimiento, Whale Rock, and Santa Margarita Reservoirs, groundwater, and recycled water for landscape irrigation. Water demand modeling estimates that these sources provide a 7.5 year combined water supply, assuming an extended worst case historical drought.

Earthquake
Earthquake events have occurred in the City in the past, including a number of magnitude 5.0 to 7.0 earthquakes. Historically, most of the earthquakes that have occurred near the City have originated from movement along the San Andreas Fault, which lies approximately 35 miles northeast of the City. The most recent major earthquake to affect San Luis Obispo occurred at 11:15:56 am Pacific Standard Time on December 22, 2003. The epicenter of the magnitude 6.5 earthquake was approximately 7 miles northeast of San Simeon at a

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.18
depth of 4.7 miles (35.706N, 121.102W), 45 miles from San Luis Obispo. The City of San Luis Obispo experienced some minor damage. The main strand of the Los Osos fault zone, also known as the Edna fault zone, traverses the City near the intersection of Los Osos Valley Road and Foothill Boulevard. Field evaluations by the California Geological Survey (CGS) for the main strand of the Los Osos fault found evidence of movement in the last 11,000 years. This evidence of recent activity resulted in the establishment of an Earthquake Fault Zone by CGS in 1989 under the Alquist- Priolo Fault Zoning Act. The Los Osos fault specifically presents a high to very high fault rupture hazard to developments near and southwest of the Los Osos Valley Road area.

Table G.11 Seismic Hazard Designation by Property Type
Seismic Designation Property Type Property Count Improved Value Los Osos Alquist-Priolo
Residential 28 $ 9,541,741
Residential: Other 2 $ 693,134
TOTAL 30 $ 10,234, 875
Source: San Luis Obispo County Planning & Building, County Assessor’ s Office, ParcelQuest, Wood Plc analysis In addition to being at risk of groundshaking as a result of a fault rupture, the City of San Luis Obispo is also susceptible to the effects of liquefaction. Most of the City is underlain by alluvium and other liquefiable sediments that may present a risk of liquefaction during ground shaking; however, liquefaction risk is generally classified as low to medium on a scale of very low to very high. Liquefaction risk is visually displayed across the City under Figure G.4 below.

Table G.12 Parcels Susceptible to Moderate Liquefaction Risk Parcel Type Parcel Count Improved Parcel Value
Commercial 992 $ 964,747,104
Government/ Utilities 125 $ 1,435,945
Other/Exempt/Miscellaneous 418 $ 170,684,946
Residential 5,282 $ 1,076,982,642
Multi-Family Residential 2,387 $ 678,902,288
Mobile/Manufactured Homes 148 $ 16,744,811
Residential: Other 673 $ 272,473,739
Industrial 36 $ 55,659,992
Vacant 42 $ 31,483,257
TOTAL 10,103 $ 3,269, 114,724
Source: San Luis Obispo County Planning & Building, County Assessor’ s Office, ParcelQuest, Wood Plc analysis

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.19
Figure G.3 Seismic Hazard Designation in the City of San Luis Obispo

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.20
Figure G.4 Liquefaction Risk in the City of San Luis Obispo

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.21
Flood
In San Luis Obispo, the most common type of flooding event is riverine flooding, also known as overbank flooding. Riverine floodplains range from narrow, confined channels in the steep valleys of mountainous and hilly regions, to wide, flat areas in plains and coastal regions. The amount of water in the floodplain is a function of the size and topography of the contributing watershed, the regional and local climate, and land use characteristics. Flooding in steep, mountainous areas is usually confined, strikes with less warning time, and has a short duration. Larger rivers typically have longer, more predictable flooding sequences and broad floodplains.

In addition to riverine flooding, San Luis Obispo is susceptible to flash flooding. Flash flood is a term widely used by experts and the general population, but no single definition or clear means of distinguishing flash floods from other riverine floods exists. Flash floods are generally understood to involve a rapid rise in water level, high velocity, and large amounts of debris, which can lead to significant damage that includes the tearing out of trees, undermining of buildings and bridges, and scouring of new channels. The intensity of flash flooding is a function of the intensity and duration of rainfall, steepness of the watershed, stream gradients, watershed vegetation, natural and artificial flood storage areas, and configuration of the streambed and floodplain. Urban areas are increasingly subject to flash flooding due to the removal of vegetation, installation of impermeable surfaces over ground cover, and construction of drainage systems. Wildfires that strip hillsides of vegetation and alter soil characteristics may also create conditions that lead to flash floods and debris flows. Debris flows are particularly dangerous due to the fact that they generally strike without warning and are accompanied by extreme velocity and momentum. Dam failure may also lead to flash flooding; however, the County’ s dam inundation as well as the California Office of Emergency Services dam inundation data confirms that there are no dam inundation zones located within the City limits.

The most serious flood events on record resulting in property damage or loss of life in San Luis Obispo occurred in 1868, 1884, 1897, 1911, 1948, 1952, 1962, 1969, 1973, 1993, 1995, 1998 , and 2001. Recent damaging floods occurred during January and March of 1995, with a lesser flooding problem in 1998. Flow during these events overtopped streambanks near the intersection of Marsh and Higuera Streets and remained out of the channel for nearly three miles downstream, with damage estimated at nearly $2.3 million. The City and Zone 9 spent approximately $1 million to repair bank erosion caused during the winter of 1995. Damage occurred near the town of Avila during both the January and March 1995 events, where high flow and debris blockages caused extensive damage to several bridges across the creek. Flooding during 1969 was significantly damaging ; two floods occurred, one at the end of January and the second at the end of February. During this two- month period, a local rain gage recorded an accumulated precipitation total of 39.79 inches. Historically, the 1969 and 1973 events were more damaging than the 1995 floods in present day dollars. The 1969 flood caused approximately $6.92 million in damage within the SLO Creek watershed. The 1973 storm caused $13.6 million along Stenner Creek, Brizziolari Creek, Prefumo Creek, and See Canyon Creek.

See Figure G.5 below illustrating the parcels at risk of flooding during a 100- or 500-year event based on the FEMA flood hazard areas.

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.22
Table G.13 100-Year and 500-Year Flooding by Jurisdiction and Parcel Type Parcel Type Parcel
Count
Improved
Value
Content
Value Total Value LossEstimate Population
100-YEAR FLOOD EVENT
Commercial 307 $ 310,143,384 $ 310,143,384 $ 620,286,768 $ 155,071,692 -- Government/ Utilities 29 $ 10,050 -- $ 10,050 $ 2,513 -- Other/ Exempt/ Miscellaneous 75 $ 29,586,337 -- $ 29,586,337 $ 7,396,584 -- Residential 338 $ 71,676,715 $ 35,838,358 $ 107,515,073 $ 26,878,768 848 Multi- Family Residential 209 $ 66,889,696 $ 33,444,848 $ 100,334,544 $ 25,083,636 525 Mobile/Manufactured Homes 5 $ 591,404 $ 295,702 $ 887,106 $ 221,777 13 Residential: Other 25 $ 42,055,551 $ 21,027,776 $ 63,083,327 $ 15,770,832 63 Industrial 6 $ 2,632,168 $ 3,948,252 $ 6,580,420 $ 1,645,105 -- Vacant 11 $ 2,988,322 -- $ 2,988,322 $ 747,081 --
TOTAL 1,005 $ 526,573,627 $ 404,698,319 $ 931,271,946 $ 232,817,987 1,448 500- YEAR FLOOD EVENT
Commercial 111 $ 74,714,129 $ 74,714,129 $ 149,428,258 $ 37,357,065 Government/Utilities 8 -- -- $ 0 $ 0 --
Other/Exempt/Miscellaneous 35 $ 19,148,234 -- $ 19,148,234 $ 4,787,059 -- Residential 971 $ 190,774,098 $ 95,387,049 $ 286,161,147 $ 71,540,287 2,437 Multi- Family Residential 297 $ 66,546,672 $ 33,273,336 $ 99,820,008 $ 24,955,002 745 Mobile/ Manufactured Homes 1 $ 245,631 $ 122,816 $ 368,447 $ 92,112 3 Residential: Other 51 $ 35,270,066 $ 17,635,033 $ 52,905,099 $ 13,226,275 128 Industrial 1 $ 312,120 $ 468,180 $ 780,300 $ 195,075 -- TOTAL 1,475 $ 387,010,950 $ 221,600,543 $ 608,611,493 $ 152,152,873 3,313 GRAND TOTAL 2,480 $ 913,584,777 $ 626,298,862 $ 1,539,883,439 $ 384,970,860 4,761 Source: San Luis Obispo County Planning & Building, County Assessor’ s Office, ParcelQuest, Wood Plc analysis, FEMA NFHL

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.23
Figure G.5 Flood Hazard Areas and Flooded Parcels in the City of San Luis Obispo

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.24
Insurance Coverage, Claims Paid, and Repetitive Losses
The City of San Luis Obispo has been a participant in the National Flood Insurance Program since April 16, 1979, and will continue to participate and remain in compliance with the National Flood Insurance Program (NFIP).

Table G.14 City of San Luis Obispo NFIP Insurance Policy Information Policies
Insurance in
Force
No. of Paid
Losses
Total Losses
Paid
736 $ 223,380,300 83 $ 456,370
Source: FEMA National Flood Insurance Program Community Information System FEMA Community Information System shows that as of April 2019 the City of San Luis Obispo has two Repetitive Loss (RL) properties and no Severe Repetitive Loss (SRL) properties.

Table G.15 City of San Luis Obispo Repetitive Loss
Repetitive Loss
Properties
Insured
Properties
Repetitive Loss
Payments ( tota)
2 1 $ 54,204.80
Source: FEMA National Flood Insurance Program Community Information System The City of San Luis Obispo joined the Community Rating Systm (CRS) on October 1, 1991. Currenlty the City has a Class 6 rating.

Critical Facilities at Risk
Critical facilities are those community components that are most needed to withstand the impacts of disaster as previously described. There are eight critical facilities found in the 100- year floodplain in San Luis Obispo, and five critical facility located in the City’s 500-year floodplain. It is particularly important to note that the critical facilities in the 500-year floodplain are all facilities that serve vulnerable populations and should be given special attention. Table G.16 below summarizes the critical facilities in the City’s 100- and 500-year floodplains. The impact to the community could be great if these facilities are damaged or destroyed during a flood event.

Table G.16 Critical Facilites in FEMA Flood Hazard Areas, City of San Luis Obispo Floodplain Critical Facility Type Facility Count
100-year
Colleges / Universities 1
Day Care Facilities 1
Microwave Service Towers 3
Nursing Homes 1
VA Medical Facilities 1
Wastewater Treatment Plant 1
500- year
Colleges / Universities 1
Day Care Facilities 1
Microwave Service Towers 1

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.25
Floodplain Critical Facility Type Facility Count
Nursing Homes 1
Private Schools 1
TOTAL 13
Source: San Luis Obispo County Planning and Building Dept., LAFCO, HIFLD, Wood Plc Parcel Analysis, FEMA NFHL Wildfire
The risk of wildland fires is greatest near the City limits where development meets rural areas of combustible vegetation. Most of the community is within one mile of a High or Very High Fire Hazard Severity Zone, which indicates significant risk to wildland fire. The City of San Luis Obispo is confronted with one of the more hazardous wildfire risks in the County due to its location near the foothills of the Santa Lucia Mountains and the Irish Hills, with increased wildfire risk in these foothills as well as on Chumash Peak, Bishop Peak, Cerro San Luis, and Islay Hill. Figure G.6 illustrates, in map form, the wildfire hazard severity zones that cross over into the City and hence pose risk to the community and its people.

Table G.17 Properties Within Moderate and Very High Wildfire Hazard Severity Zones Parcel Type Parcel
Count
Improved
Value
Content
Value
Total
Value
Loss
Estimate Population

MODERATE WILDFIRE HAZARD SEVERITY
Commercial 1 $ 2,392,765 $ 2,392,765 $ 4,785,530 $ 4,785,530 -- Government/ Utilities 1 -- -- $ 0 $ 0 --
Other/ Exempt/ Miscellaneous 1 -- -- $ 0 $ 0 --
Residential 3 $ 218,358 $ 109,179 $ 327,537 $ 327,537 8 TOTAL 6 $ 2,611,123 $ 2,501,944 $ 5,113,067 $ 5,113,067 8

VERY HIGH WILDFIRE HAZARD SEVERITY
Other/ Exempt/ Miscellaneous 2 -- $ 2 $ 2 --
Residential 14 $ 7,928,870 $ 3,964,435 $ 11,893,319 $ 11,893,319 35 Vacant 1 $ 40,500 -- $ 40,501 $ 40,501 --
TOTAL 17 $ 7,969,370 $ 3,964,435 $ 11,933,822 $ 11,933,822 35 GRAND TOTAL 23 $ 10,580,493 $ 6,466,379 $ 17,046,889 $ 17,046,889 43 Source: San Luis Obispo County Planning & Building, County Assessor’ s Office, ParcelQuest, Wood Plc analysis, CalFire

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.26
Figure G.6 Wildfire Hazard Severity Zones

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.27
Human Caused: Hazardous Materials
The Cal OES Warning Center reports 419 hazardous materials incidents in the City of San Luis Obispo from 1994 through October 24, 2018; as noted in Section 5.3.13 of the county plan, this likely excludes a large number of unreported minor spills. This constitutes 23% of the hazardous materials incidents reported countywide during the same time frame, and averages out to roughly 16.8 incidents per year. As noted in Section 5.3.13, only around 6% of reported hazardous materials incidents result in injuries, fatalities, or evacuations.

There is one CalARP regulated facilities and no EPA Risk Management Plan ( RMP) facilities located in the City.

Additionally, the City sits within the Emergency Planning Zone for the Diablo Canyon Nuclear Power Plant .

G.4 Capability Assessment
Capabilities are the programs and policies currently in use to reduce hazard impacts or that could be used to implement hazard mitigation activities. This capability assessment is divided into six sections: regulatory mitigation capabilities, administrative and technical mitigation capabilities, fiscal mitigation capabilities, mitigation outreach and partnerships, other mitigation efforts, and opportunities for enhancement.

To develop this capability assessment, the jurisdictional planning representatives used a matrix of common mitigation activities to inventory policies or programs in place. The team then supplemented this inventory by reviewing additional existing policies, regulations, plans, and programs to determine if they contributed to reducing hazard-related losses.

During the plan update process, this inventory was reviewed by the jurisdictional planning representatives and Wood consultant team staff to update information where applicable and note ways in which these capabilities have improved or expanded. In summarizing current capabilities and identifying gaps, the jurisdictional planning representatives also considered their ability to expand or improve upon existing policies and programs as potential new mitigation strategies. The City of San Luis Obispo’s updated capabilities are summarized below.

G.4.1 Regulatory Mitigation Capabilities
Table G.18 City of San Luis Obispo Regulatory Mitigation Capabilities Regulatory Tool
ordinances, codes, plans) Yes/ No Comments
General Plan Yes
Land Use Element, Circulation Element, Housing Element, Noise Element, Safety Element, Conservation and Open Space Element, Parks and Recreation Element, and Water and Wastewater Element Zoning ordinance Yes Title 17: Zoning Regulations of the City of San Luis Obispo Municipal Code
Subdivision ordinance Yes Title 16: Subdivisions, Subdivision Regulations Growth management ordinance Yes Chapter 17.144: Residential Growth Management Regulations Floodplain ordinance Yes Chapter 17.78: Flood Damage Prevention Other special purpose ordinance
stormwater, steep slope, wildfire) Yes
Ordinance 1543: Chapter 12.08 Urban Storm Water Quality Management and Discharge Control
Ordinance 1490: Chapter 16.20 Physical Improvement Standards and Procedures - 16.20.040 Grading plan
Ordinance 1490: Chapter 16.18 General Subdivision Design Standards

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.28
Regulatory Tool
ordinances, codes, plans) Yes/ No Comments
Chapter 17.70.090: Hillside Development Standards
Ordinances 1630 ( part) and 1595 ( part), Chapter 15.04 Construction and Fire Prevention Regulations
A Stormwater Control Plan is required to be submitted for all projects to demonstrate exemption or level of compliance required.

Post Construction Regulation outlines Stormwater Control Plan content in Performance Requirement 2 - Sections B.3.c,
Performance Requirement 3 - Section B.4.g, and Performance Requirement 4 – Section B.5.b. Through the Stormwater Control Plan submittal, applicants demonstrate compliance with Post Construction Requirements or exemption status.

Drainage Design Manual ( Design Manual) has been developed to provide criteria and planning procedures for floodplains, waterways, channels, and closed conduits in the San Luis Obispo Creek watershed. This Drainage Manual will be used by the City of San Luis Obispo and San Luis Obispo County Flood Control and Water Conservation District Zone 9 (SLO/ Zone 9) staff in their internal design of stormwater drainage, flood management and bank stabilization and restoration projects.

Building code Yes
Title 15, Buildings and Construction of the City of San Luis Obispo Municipal Code. California Building Codes:

CA Residential Code ( 2016); CA Plumbing Code ( 2015 UPC); CA Mechanical Code ( 2015 UMC); CA Electrical Code ( 2014 NEC); CA Energy Code ( 2016); CA Green Building Code ( 2016); CA Fire Code 2015 IFC); CA Reference Standards Code (2016)
Fire department ISO rating Yes 2
Erosion or sediment control program Yes
Chapter 17.78 Flood Damage Prevention
Chapter 12.08 Urban Storm Water Quality Management and
Discharge Control
Chapter 16.20 Physical Improvement Standards and Procedures Ordinance 1543, Code Section 12.08.150 Requirement to prevent, control, and reduce storm water and pollutants
City of SLO Waterway Management Plan and Drainage Design Manual
Annual silt removal to maintain hydraulic capacity in San Luis Obispo creek beds to reduce flooding. City has 14 total sites in the management plan and complete silt removal on a rotating basis.

Stormwater management program Yes Chapter 12.08: Stormwater Regulations & Requirements Site plan review requirements Yes Title 22 Article 3
Capital improvements plan Yes Department of Public Works 5-Year Strategic Plan Economic development plan Yes 5-Year Economic Development Strategic Plan Updated in 2015 Local emergency operations plan Yes City of San Luis Obispo Emergency Operations Plan (2011) Other special plans Yes
Open Space Conservation Plans, Climate Action Plan, Urban Water Management and Water Shortage Contingency Plans, Waterway Management Plan, Utilities Department Emergency Plan,

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.29
Regulatory Tool
ordinances, codes, plans) Yes/ No Comments
Unreinforced Masonry Hazard Mitigation Program, Disaster Preparedness Program, Community Wildfire Preparedness Plan, Greenbelt Protection Program
Flood insurance study or other
engineering study for streams Yes 2012
Elevation certificates ( for floodplain
development) Yes Chapter 17.78: Flood Damage Prevention Other Yes
Water System Vulnerability Assessment, Floodplain Management Educational Program
G.4.2 Administrative/ Technical Mitigation Capabilities There are several key departments and staff within the City organization that serve a specific role in developing and implementing hazard mitigation activities. City government consists of approximately 399 full-time equivilent employees and 10 departments: Police, Fire, Public Works, Public Utilities, Community Development, Parks and Recreation, Human Resources, Finance and Information Technology, City Administration, and the City Attorney’s Office. With a clear set of policies in place and a diverse range of staff available to mitigate identified hazards within the City, the City has many staff with specific training on the use of specialized equipment or particular areas of expertise that are essential in implementing mitigation actions. Technical resources are considered to be physical infrastructure or equipment available to the City to aid in implementing hazard mitigation or disaster response activities. Table G.19 identifies the personnel resources and technical resources that increase capabilities related to mitigation and loss prevention in the City.

Table G.19 City of San Luis Obispo Administrative/Technical Mitigation Capabilities Personnel Resources Yes/ No Department/Position
Planner/engineer with knowledge of
land development/ land management
practices
Yes Staff with knowledge of land development practices and local land development patterns.

Engineer/ professional trained in
construction practices related to
buildings and/ or infrastructure
Yes Professionals trained in construction practices associated with buildings and infrastructure and in storm water compliance during construction and operation of buildings and infrastructure projects.

Planner/ engineer/ scientist with an
understanding of natural hazards
Yes
Personnel skilled in GIS
Yes Provide accurate and comprehensive Geographic Information System for managing resources, make informed decisions, and expedite work processes.

Full time building official Yes Community Development Department, Chief Building Official Floodplain manager Yes Community Development Department, Supervising Civil Engineer Emergency manager
Yes Accomplished through contract services. City maintains funding for the 2019-21 Financial Plan to maintain an Emergency Manager position equivalent to 0.5 FTE.

Grant writer
Yes Accomplished through Contract Services. The City maintains twoyear contracts with both a local grant writing firm and grant advocate firm based out of Irvine, CA.

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.30
Personnel Resources Yes/ No Department/ Position
Mutual Aid Agreements
Yes Establishes agreements among local jurisdictions to assist in emergency response efforts in neighboring jurisdictions during times of need. San Luis Obispo currently participates in the following mutual aid agreements: 1. California Master Mutual Aid Agreement, 2. SLO County Fire and Rescue Mutual Aid Agreement,

3. California Fire Assistance Agreement, 4. Region 1A Law Enforcement Mutual Aid Agreement, 5. Public Works Mutual Aid Agreement, 6. California Emergency Managers Mutual Aid
Agreement, 7. Regional Disaster Medical/Health Coordination.

Code Enforcement and Neighborhood
Services
Yes Staff with training and expertise in identifying hazards to health, safety, and welfare, and assisting property owners with achieving code and policy compliance.

Fire Marshal
Yes Measure G funded position, manages and directs the activities of the Fire Prevention Bureau. Oversees fire safety inspections for all facilities in the City. Ensures that development in the City meets fire safety standards. Obtains funding and implements wildland fuel reduction projects. Directs and oversees fire investigations.

Fire Inspectors
Yes Professionals trained in fire prevention techniques and construction practices associated with buildings and infrastructure. Inspect all multi- family residential buildings and public assembly buildings.

Review building plans and inspect construction projects for fire and life safety and proper installation of fire protection systems.

Investigate fire for cause and origin.

Hazardous Materials Coordinator
Staff designated to inspect facilities and containers storing hazardous materials. There are approximately 244 facilities located within the City that are permitted for the use of hazardous materials.

Network Administrators Yes Provide technical support for wired/ wireless network and radios.

Park Rangers Yes Staff familiar with brush clearance requirements and conditions of City- owned open space.

Police Officers
Yes Emergency response to provide protection of life, property and address community safety/ security needs. Work cooperatively with other first responders for an organized response to disaster mitigation plans.

Dispatchers Yes Provide communication links to responding personnel to transfer emergency information and direct resources as needed.

Construction Inspection Yes Ensures storm water compliance during construction of City projects, and private grading and encroachment projects.

Public Works Department – Department
Operations Centers ( DOC)
Yes The Public Works DOC coordinates responses to road flooding and related problems during a storm with road crews, the County, Caltrans, and the California Highway Patrol. They also support other emergency response operations coordinated through the City’ s EOC.

Storm Water Compliance
Yes Staff responsibility assigned to ensure storm water compliance during construction and operation of buildings and infrastructure projects.

Other personnel Yes Operations: Field staff provide assistance to Public Works DOC for flood response, and City EOC for general emergency response.

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.31
Personnel Resources Yes/ No Department/ Position
GIS Data Resources
Hazard areas, critical facilities, land use,
building footprints, etc.)
Yes
Warning systems/ services
Reverse 9-11, outdoor warning signals)
Yes
Voluntary Organizations Active in
Disaster
Yes Provides disaster preparedness courses to residents and community members and provides care and shelter to those threatened or impacted by natural hazards. Volunteer and private agencies are essential to the area’s mutual aid system by providing for the care and shelter needs of disaster victims. Organizations active in San Luis Obispo include the American Red Cross and Salvation Army.

G.4.3 Fiscal Mitigation Capabilities
There are multiple financial and funding opportunities for the City to mitigate or respond to natural hazards.

These capabilities include local revenues from the general fund, or the receipt of grant funds from state or federal agencies. The City’s financial planning process includes a two-year goal setting and budget development based on community and council priorities. The City’ s five- year fiscal forecast identifies the City’ s forecast of revenues, expenditures, and changes in fund balance. The general fund receives revenues from a variety of sources including taxes ( sales, property, transient occupancy, business, utility users), subventions and grants vehicle license fees, gas tax, and other subventions), service charges (development review fees, recreation fees), and other revenues ( fines, interest earnings, and rents). The City has and will continue to utilize the two -year goal setting and budget process to prioritize expenditures needed to mitigate future hazards. In the event of a natural disaster and a need for immediate City response, the City has the financial capacity to utilize reserve funds, when authorized by the City Council. The City has previously utilized the following financial resources to implement hazard mitigation activities. The added revenues to the General Fund from Measure “G” have allowed the City to financially support major improvements in the areas of public safety, flood protection, and open space preservation. Financial resources to mitigate hazards: Table G.20 identifies financial tools or resources that the City could potentially use to help fund mitigation activities.

Table G.20 City of San Luis Obispo Fiscal Mitigation Capabilities Financial
Resources
Accessible/ Eligible
to Use ( Yes/ No)
Comments
Community
Development
Block Grants
Yes
The City continues to seek grant opportunities through the CDBG program and identify potential eligible projects that would fund mitigation activities to benefit the health and welfare of the community.

Capital
improvements
project funding
Yes
The Capital Improvement Plan (CIP) enables the City to plan, schedule, and finance capital projects to ensure cost effectiveness and conformance with established plans and policies. The City’s budget process guides the capital priorities through community input, Council goal setting, Local Revenue Measure priorities, and the biennially adopted Major City Goal work programs. The City’ s CIP includes all planned infrastructure projects over a five- year period. The first two years identify those projects that are planned to be funded and/ or completed during the adopted two- year

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.32
Financial
Resources
Accessible/ Eligible
to Use (Yes/ No)
Comments
financial plan. The latter three years serve as the framework for future Financial Plans’ capital budgets. The plan represents a phased approach to funding the projects needed to maintain the City’ s infrastructure and major facilities over the entire five- year period.

Authority to levy
taxes for specific
purposes
Yes
Taxes for specific purposes can be levied with authorization from the City Council and further approval through a local ballot measure.

Fees for water,
sewer, gas, or
electric services
Yes
The City's utilities department provides water and wastewater services to the residents and businesses of San Luis Obispo. Water and sewer revenues are collected to support operations and capital improvements, with rates reviewed on an annual basis and approved by the City Council.

These revenues from customer water and sewer use are utilized by the utilities department to maintain, improve, expand and replace components of the City' s water and wastewater infrastructure system, including improvements made to protect from natural hazards.

Impact fees for
new development
Yes
New development projects proposed in the City affect the City' s ability to provide adequate essential services ( e.g. transportation, water and wastewater, and open space). To ensure these essential services can adequately serve the City' s existing and future community needs, a series of development impact fees are levied on new development projects.

Incur debt
through general
obligation bonds
Yes
Debt can be incurred through general obligation bonds with authorization from the City Council and further approval through a local ballot measure.

Incur debt
through special
tax bonds
Yes
Debt can be incurred through special tax bonds with authorization from the City Council and further approval through a local ballot measure.

Incur debt
through private
activities
Yes
City Financial Policy allows debt to be incurred through private activities with approval from City Council
Withhold
spending in
hazard prone
areas
Yes
Policy is accessible with authorization from City Council.

General Fund
including
Measure G
Funding)
Yes
In 2006, City voters approved measure Y to preserve and enhance essential City services by establishing a 1/ 2 –cent City sales tax. In the 2011/12 fiscal year, measure Y generated approximately $6.2 million in revenue. This funding has been used in recent years for public safety, infrastructure maintenance, traffic congestion relief, neighborhood code enforcement and open space acquisition project. Many of the projects funded through measure Y revenues are considered to help mitigate hazard throughout the community. In 2014 Measure Y was approved to be extended through ballot measure G, which will sunset in 2022 unless a new measure is passed to continue the collection of additional sales tax.

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.33
Financial
Resources
Accessible/ Eligible
to Use (Yes/ No)
Comments
Reserve Funds Yes
The City’s budget and fiscal policies includes a requirement to maintain adequate fund reserves for both general and enterprise funds. The minimum reserve level is 20% of annual operating expenditures.

Building Permit
Inspection and
Review Fees
Yes
Fees are collected by the planning and building divisions of the community development department to inspect and review construction documents on proposed projects within the City. The collection of these fees ensures buildings are designed and constructed in a manner consistent with applicable components of the municipal code and helps the department to recover staff costs associated with review and inspection.

G.4.4 Mitigation Outreach and Partnerships
Throughout the planning process of the Multi-jurisdictional HMP, the City participated in local outreach by promoting public meetings and circulating the Public Draft of the HMP for public comment and review . Public comments have been addressed and have been incorporated into the final HMP, where applicable. To further support implementation of hazard mitigation activities, the City has established strong partnerships with its neighboring jurisdictions, San Luis Obispo County, and multiple state organizations such as the California Highway Patrol, Cal Poly, CalFire, and Caltrans to collectively address local hazards. These partnerships have been formalized through the following:

Mutual Aid Agreements
Voluntary Organizations Active in Disaster
San Luis Obispo County Community Fire Sage Council
Department Operations Centers (DOC)
The City of San Luis Obispo also coordinates with many external (local, state, federal, and private sector) agencies which have capabilities to support hazard mitigation activities. Many of these agencies participated in the hazard mitigation planning process to update this plan, including the following:

County of San Luis Obispo – Airports
County of San Luis Obispo – Office of Emergency Services County of San Luis Obispo – Public Health Department
Cal Poly – City & Regional Planning Department
Cal Poly – Administration and Finance
French Hospital Medical Center
American Red Cross
Sierra Vista Regional Medical Center
San Luis Coastal Unified School District
California Highway Patrol
Pacific Gas and Electric Company (PG& E)

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.34
G.4.5 Other Mitigation Efforts
In addition to the plan and policy resources available to the City to mitigate hazards, the City has developed or participated in several hazard mitigation programs including:

Unreinforced Masonry Hazard Mitigation Program
Disaster Preparedness Program
Floodplain Management Educational Program
San Luis Obispo Chamber of Commerce Business Continuity Planning County Public Health Emergency Preparedness Advisory Committee National Flood Insurance Program ( NFIP) and FEMA Repetitive Loss Properties Community Wildfire Protection Program
Greenbelt Protection Program
G.4.6 Opportunities for Enhancement
Based on the capability assessment, the City has several existing mechanisms in place that help to mitigate hazards. There are also opportunities for the City to expand or improve on these policies and programs to further protect the community. Future improvements may include providing training for staff members related to hazards or hazard mitigation grant funding in partnership with the County and Cal OES. Additional training opportunities will help to inform City staff members on how best to integrate hazard information and mitigation projects into their departments. Continuing to train City staff on mitigation and the hazards that pose a risk to the City will lead to more informed staff members who can better communicate this information to the public.

The following themes or opportunities were identified during the planning process of the 2014 LHMP:

Actions to Prepare – While many members of the community have taken small actions to prevent damage to their home in the event of a natural hazard, only a small portion have completed larger structural items to prevent damage. The City may consider developing and implementing programs to support risk reduction activities by property owners. Using the data available as a result of the risk assessment in this HMP, the City is able to identify areas and structures with a higher risk or exposure to the identified hazards. Sharing this information with community members and evaluating opportunities to help property owners in funding risk reduction activities will increase the resiliency of San Luis Obispo.

Awareness of Neighbor Needs – Given the high student population and regular turnover of neighbors in some neighborhoods, it can be challenging for community members to be fully aware of neighbors and their needs. Neighborhood events such as the annual community block parties are an opportunity for the City to support greater community interaction which can increase awareness of neighbors needs in the event of an emergency.

Community or Workplace Awareness – In many cases, respondents were unaware or unsure of the hazards that may affect the community or their workplace and policies that may be in place to help respond to a natural disaster. The City can help to increase community awareness through wider promotion or participation in workshops or resources available to the community that have already been prepared by the City or volunteer organizations. The City may increase business owners’ awareness of risk by providing emergency planning support, continuity of operations planning support, and potentially hosting seminars for the business community to learn about the hazard risks.

Understanding the Extent of Damages – To better understand the extent of damages to homeowners from a natural disaster, the City could coordinate with homeowner insurance providers to track damages beyond those reported through the National Flood Insurance Program (NFIP).

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.35
G.5 Mitigation Strategy
G.5.1 Mitigation Goals and Objectives
The City of San Luis Obispo Planning Team determined the two goals from the 2014 LHMP continue to be appropriate for this plan update, with the addition of a third goal to address hazards exacerbated by the impacts of climate change. The following are the City of San Luis Obispo’s 2019 mitigation goals:

Goal 1: Cultivate a disaster-resistant and resilient community through implementation of risk reduction measures and increased public awareness to prepare for, respond to, and recover from natural and human - caused hazard events.

Objective 1.A Ensure that local plans, policies, and programs are consistent with the hazard information identified in the LHMP.

Objective 1.B Increase City employee capacity through SIMS and NIMS compliant training and EOC drills to identify hazards, and assist in emergency preparedness, response, and recovery.

Objective 1.C Pursue available grant funding to implement hazard mitigation efforts.

Objective 1.D Maintain critical and essential key assets to increase resiliency and minimize future damage from hazard events.

Objective 1.E Increase public awareness of hazards, emergency response, and recovery.

Objective 1.F Promote public/private partnerships to increase community resiliency.

Goal 2: Reduce the severity of damage and losses due to natural and human-caused hazards.

Objective 2.A Protect and enhance, as practical, existing assets, as well as any future development, from the effects of natural and human-caused hazards.

Goal 3: Prepare for and adapt to the impacts of climate change.

Objective 3.A Use, and update as needed, the best available science to estimate exposure, vulnerability, and risk of hazards as the result of climate change.

Objective 3.B Use the climate change exposure, vulnerability, and risk assessments to ensure mitigation investments, capital projects, and programs actively mitigate climate impacts.

Continued Compliance with the National Flood Insurance Program (NFIP) The City has been an NFIP participating community since 1973 and will continue to comply with the NFIP. This includes ongoing activities such as enforcing local floodplain development regulations, including issuing permits for appropriate development in Special Flood Hazard Areas and ensuring that this development is mitigated in accordance with the regulations. This will also include periodic reviews of the floodplain ordinance to ensure that it is clear and up to date and reflects new or revised flood hazard mapping. The goals of the NFIP are to reduce future flood damage through floodplain management and to provide people in participating communities with flood insurance. Community participation is voluntary. The City is also part of the Community Rating System CRS), currently rated at Class 7. The goals of the CRS are to reduce flood damages to insurable property, strengthen and support the insurance aspects of the NFIP, and encourage a comprehensive approach to floodplain management. The City of San Luis Obispo maintains full compliance with the NFIP through Sections

17.84.010- 17.84.170 within Chapter 17.84 Flood Damage Prevention Regulations of the San Luis Obispo Municipal Code, which sets forth means to reduce losses from floods. These standards focus on areas located within or near the 100-year floodplain. Section 8.12.010-8.12.010 of the Municipal Code provides a mechanism for the City to require the removal of dangerous obstructions in streambeds that have the potential to obstruct water flow.

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.36
FEMA insures properties against flooding losses through the NFIP. As part of the process to reduce or eliminate repetitive flooding to structures across the United States, FEMA has developed an official Repetitive Loss Strategy. The purpose behind the national strategy is to identify, catalog, and propose mitigation measures to reduce flood losses due to the relatively few structures that represent the majority of claims from the National Flood Insurance Fund. A Repetitive Loss property is defined by FEMA as a “property for which two or more NFIP losses of at least $ 1,000 each have been paid within any 10- year period since 1978.” The City of San Luis Obispo has two Repetitive Loss properties. As a CRS requirement, the City Public Works Department sends community outreach notifications and letters to property owners in repetitive loss areas, including the City’s Mid Higuera Area, to inform residents of flooding and to offer ways in which property owners can prepare for and reduce the damage from repetitive flooding. In addition, the Public Works Department conducted storm drain improvements as part of a Capital Improvements Project that helped with flood control in the Mid Higuera Area, an area of repetitive flooding. FEMA also defines Severe Repetitive Loss properties; however, the City does not have any Severe Repetitive Loss properties.

G.5.2 Completed 2014 Mitigation Actions
During the 2019 planning process the City of San Luis Obispo Local Planning Team reviewed all the mitigation actions from the 2014 LHMP. The review indicated the City has completed one mitigation action since 2014 and made continued progress in implementing mitigation projects and building the community’s resilience to disasters. Of the 29 mitigation actions identified in the 2014 LHMP, the Planning Team has completed the following action, which the Planning Team notes as being completed in January of 2017:

2.A.12 Add gas pipeline mapping to the City’ s GIS resources.

G.5.3 Mitigation Actions
The City of San Luis Obispo Local Planning Team identified and prioritized one new mitigation action based on the 2019 risk assessment. New and existing actions were prioritized using the process described in Section 7.2.1 of the Base Plan. The new mitigation action identifies implementation strategies, the responsible agency, potential funding, estimated cost, and implementation schedule.

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.36
Table G.21 City of San Luis Obispo’s Mitigation Action Plan ID Hazard( s)
Mitigated Description/ Background/ Benefits Lead Agencyand Partners Cost
Estimate
Potential
Funding Priority Timeline Status/ Implementation Notes
SL.1*
Adverse
Weather,
Biological,
Earthquake,
Flood,
Wildfire,
Hazardous
Materials
Regularly review and continue to maintain
consistency between the Safety Element,
Municipal Code, zoning regulations, hazard
area maps, and LHMP implementation
strategies. Added 10/2016: Review the
implementation and impacts of SB1069 Land
use zoning
Community
Development
Public Works
Fire
Little to
no cost
Staff Time/
Dept.

Budget
Medium 1-3 years
In progress. Safety
Element to be updated
in 2021
SL.2
Adverse
Weather,
Biological,
Earthquake,
Flood,
Wildfire,
Hazardous
Materials
Train all City employees including fire
fighters, police officers, building inspectors,
and public works and utilities staff to levels
appropriate for their hazard mitigation tasks
and responsibilities.

Fire Little to
no cost
Staff Time/
Dept.

Budget
Medium 1-3 years
In progress. Currently
updating a City-wide
training matrix to
ensure employees have
the valid training based
on their position. Once
the matrix is complete
the City will hold
training to ensure all
City employees receive
appropriate training and
certifications. Utilize
new Human Capital
Management software
to ensure new
employees receive
training during
onboarding.

SL.3
Adverse
Weather,
Earthquake,
Flood,
Wildfire,
Provide training for City staff who apply its
building regulations and planning standards,
emphasizing the lessons learned in locations
that have experienced disasters
Fire /
Community
Development
Public Works
Little to
no cost
Staff Time/
Dept.

Budget
Medium 1 yr.

In progress. Additional
modeling has been
completed. The results
of this modeling
indicated that a more
expansive model should

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.37
ID Hazard( s)
Mitigated Description/ Background/ Benefits Lead Agencyand Partners Cost
Estimate
Potential
Funding Priority Timeline Status/ Implementation Notes
Hazardous
Materials
be created which is
underway.

SL.4
Adverse
Weather,
Biological,
Earthquake,
Flood,
Wildfire,
Hazardous
Materials
Conduct disaster- preparedness exercises for
the types of hazards discussed in this LHMP. Fire Little tono cost Staff Time/
Dept.

Budget
Medium 1 yr.

In progress. Latest
Public Point of
Distribution drill held at
the City of San Luis
Obispo was on
10/ 18/ 2017. October
2018 Distribution took
place on 10/ 21/ 18 in
Arroyo Grande and
Atascadero ( the two
locations exercised were
intended to cover the
whole county, including
SLO). City plans to
continue participating in
exercises as allowed.

SL.5
Adverse
Weather,
Biological,
Earthquake,
Flood,
Wildfire,
Hazardous
Materials
Establish ongoing Disaster Service Worker
training program to include training for City
staff to deal with emergencies as well as
contribute to risk reduction measures.

Fire Little to
no cost
Staff Time/
Dept.

Budget
Medium 1 yr. In progress
SL.6
Adverse
Weather,
Biological,
Earthquake,
Flood,
Wildfire,
Review funding opportunities and establish
centralized internal procedures to coordinate
efforts for securing funds that support risk
reduction measures.

Admin. -
Finance
Little to
no cost
General
Funds/

FEMA HMA
High 1 yr.

In progress. Spring of
2019. The City released
an RFP to hire a grant
writing firm to seek
funding opportunities
to leverage community

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.38
ID Hazard( s)
Mitigated Description/ Background/ Benefits Lead Agencyand Partners Cost
Estimate
Potential
Funding Priority Timeline Status/ Implementation Notes
Hazardous
Materials
improvement. This
includes risk reduction
measures.

SL.7
Adverse
Weather,
Biological,
Earthquake,
Flood,
Wildfire,
Hazardous
Materials
Identify hazard mitigation projects eligible for
grants as part of the Capital Improvement
Program planning process.

Public Works/
Utilities
Little to
no cost
Cal OES
FEMA: Up
to $2
Million at
WRRF
Medium 3-5 years
In progress. The MidHiguera Bypass project
is currently being
designed. Once design
is complete, grant
application work will
begin. Utilities ( new) - A
2 million grant
application has been
submitted with CalOES
for flood proofing
mission critical facilities
related the Water
Resource Recovery
Facility.

SL.8
Adverse
Weather,
Earthquake,
Flood,
Hazardous
Materials
Assess structural capacity of key assets
including bridges) and pursue infrastructure
improvements as necessary.

Public Works/
Community
Development
Less than
10,000
General
Fund Medium 3-5 years
In progress. As part of
2019- 21 financial plan
process the City has
reviewed and prioritized
assets maintenance and
replacement. This
prioritized asset list will
be presented to the City
Council for funding
consideration.

SL.9
Adverse
Weather,
Biological,
Earthquake,
Flood,
Establish a funded program or mechanism to
distribute public information regarding risk
reduction activities and projects at Citysponsored events. Identify materials available for use at public education workshops.

Fire Little to
no cost
General
Fund Medium 1-2 years
In progress. Fire
Prevention Open House
occurred on and
10/14/17 and 10/13/18.

Presentations at Cal

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.39
ID Hazard( s)
Mitigated Description/ Background/ Benefits Lead Agencyand Partners Cost
Estimate
Potential
Funding Priority Timeline Status/ Implementation Notes
Wildfire,
Hazardous
Materials
Coordinate messaging with external agencies
such as the American Red Cross and
Volunteer Organizations Active in Disasters.

Poly orientations for
students and their
parents. Department is
developing new disaster
preparedness
neighborhood
presentation program
and employee disaster
worker preparedness
beginning FY2020.

SL.10
Adverse
Weather,
Biological,
Earthquake,
Flood,
Wildfire,
Hazardous
Materials
Support the efforts and education of people
with access and functional needs to prepare
for disasters.

Fire Little to
no cost
Staff Time/
Dept.

Budget
Medium 1 yr. In progress
SL.11
Adverse
Weather,
Biological,
Earthquake,
Flood,
Wildfire,
Hazardous
Materials
Educate the community on individual
preparedness and response to deal with
emergencies at times when professional
responders would be overwhelmed.

Fire Little to
no cost
General
Fund Medium 1-2 years
In progress. See SL.9
comments
SL.12
Adverse
Weather,
Biological,
Earthquake,
Flood,
Wildfire,
Offer seminars and/ or resources to assist
local / small businesses in planning for
continuity of operations and emergency
preparedness.

Fire Little to
no cost
General
Fund Medium 1-2 years
In progress. Fire
department staff attend
the weekly meetings at
the Downtown
Association and has
updated a fire safety
checklist for festival

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.40
ID Hazard( s)
Mitigated Description/ Background/ Benefits Lead Agencyand Partners Cost
Estimate
Potential
Funding Priority Timeline Status/ Implementation Notes
Hazardous
Materials
vendors in the
downtown, provided
education to DTA staff.

SL.13*
Adverse
Weather,
Biological,
Earthquake,
Flood,
Wildfire,
Hazardous
Materials
Continue to enforce local codes, ordinances,
and standards pertaining to safe
development and resiliency to natural and
human- caused hazards.

Community
Development
Fire
Little to
no cost
General
Funds/

FEMA HMA
High 1-2 years
In progress. As of April
of 2019, permits have
been issued on all URM
structures. All have been
finalized/ closed out
except for four
properties, one of which
is currently being
retrofitted and
remodeled ( SLO Brew at
736 Higuera). Permits
have been issued on
two others ( 1029 and
1035 Chorro) but have
not been
finalized/ closed out in
permitting
system. Current status
on these is currently
being researched.

Records indicate the last
of the four has
completed Level A
strengthening, but still
has an outstanding
permit - permit records
and status is currently
being researched.

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.41
ID Hazard( s)
Mitigated Description/ Background/ Benefits Lead Agencyand Partners Cost
Estimate
Potential
Funding Priority Timeline Status/ Implementation Notes
SL.14 Earthquake
Develop and provide managers of mobile
home parks with information on how to
improve the seismic performance of mobile
homes and awareness of flood risk.

Community
Development
Less than
10,000
Staff Time/
Dept.

Budget
Medium 2-3 yrs.

In progress.

Still in planning process;
will be incorporated into
Safety Element)
SL.15
Earthquake,
Wildfire,
Adverse
Weather
The Secure and Resilient Electricity action
would plan for energy independence and
security at critical facilities throughout the
City. By providing grid independent onsite
renewable energy, storage, and energy
management systems, and by providing a
planning and financing framework for future
investments, the City will be able maintain
uninterrupted operations during times of
electricity or natural gas grid instability.

Fire; police;
public works;
utilities;
administratio
n; parks and
recreation
200k to
500k;
California
Energy
Commissio
n;
Monterey
Bay
Community
Power
High 3-5 yrs.

New
Benefits: A resilient
electricity system ( solar
and storage) at critical
facilities ensure ongoing
operations during
significant disaster
events and ensures
viability of electric
evacuation vehicles, City
fleet, and transit
vehicles.

SL.16 Earthquake
Continue to implement the Unreinforced
Masonry Hazard Mitigation Plan and
strengthen buildings identified in Levels A
and B.

Community
Development
Fire
10,000
to
50,000
General
Funds/ FEM
A HMA
Medium 2-3 yrs.

In progress. See SL.13
comments
SL.17 Flood Develop and carry out environmentally
sensitive flood reduction programs.

Administratio
n - Natural
Resources
10,000
to
50,000
FEMA HMA Medium 2-3 yrs.

In progress. The City
continues to assess high
priority erosion and
sedimentation sites
identified in the
Waterway Management
Plan and provide
maintenance or
restoration as
appropriate; review City
owned property and
property with drainage
easements covering

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.42
ID Hazard( s)
Mitigated Description/ Background/ Benefits Lead Agencyand Partners Cost
Estimate
Potential
Funding Priority Timeline Status/ Implementation Notes
private properties and
conduct vegetation
management/ removal
as needed; and,
complete silt removal
projects at key drainage
locations on a rotating
basis. Assess and
remove as necessary
undesirable trees from
creek system with
tree/ landscape
contractors. Natural
Resources Program staff
manages vegetation
trimming or removal to
maintain the riparian
corridors. The EIR for
the Mid- Higuera Bypass
project was adopted
and the 95% plans are
nearing completion.

SL.18 Haz Mat
Continue requiring businesses that use, store,
or transport hazardous materials to ensure
that adequate measures are taken to protect
public health and safety.

Fire Little to
no cost
Certified
Unified
Program
Agency
CUPA)
High
Annual
impleme
ntation
Fire Department CUPA
Participating Agency
completes 100% of
permitted facility
inspections annually to
assure compliance with
the fire code and state
regulations. The fire
department is subject to
audit by the County

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.43
ID Hazard( s)
Mitigated Description/ Background/ Benefits Lead Agencyand Partners Cost
Estimate
Potential
Funding Priority Timeline Status/ Implementation Notes
CUPA and has passed
all recent audits.

SL.19 Haz Mat
Coordinate with allied agencies to prepare for
hazardous materials incidents. Reference City
EOP and Training and Exercise Plan; Maintain
participation in County hazardous materials
team
Fire Less than
10,000
Certified
Unified
Program
Agency
CUPA)
Medium 1 yr.

In progress. City
Emergency Operations
Plan is currently set to
be updated. City issued
RFP to hire consultant
to update plan in Spring
of 2019 and is expected
to have a completed
plan with associated
training in Winter of
2020.

SL.20 Haz Mat
Maintain City’ s web site and other outlets
with information regarding the safe handling
and disposal of household chemicals.

Fire Little to
no cost
Staff
Time/ Dept.

Budget
Medium 1 yr. In progress/ ongoing
SL.21 Wildfire
Enhance partnerships with CalFire and the
local Fire Safe Council for fuel reduction
efforts.

Fire Little to
no cost
Cal Fire /
FireSafe
Grants
Medium 1 yr.

In progress. As of March
of 2019, The City of San
Luis Obispo is now a
recognized focus group
and voting board
member on the Fire
Safe Council
SL.22 Wildfire,
Drought
Support ongoing urban forest maintenance
and tree trimming programs, to include
planting drought- resistant trees and plants.

Public Works
Urban
Forestry / Fire
Parks &
Recreation /
Natural
Resources
Less than
10,000
General
Fund Medium 1-2 yrs.

In progress. Urban
Forest Services
continues regular
maintenance which
includes pruning and
dead tree removal in
City Streets, Parks and
other City owned
properties.

Annex G: City of San Luis Obispo
San Luis Obispo County Local Hazard Mitigation Plan
City of San Luis Obispo | February 2020 Annex G.44
ID Hazard( s)
Mitigated Description/ Background/ Benefits Lead Agencyand Partners Cost
Estimate
Potential
Funding Priority Timeline Status/ Implementation Notes
SL.23 Wildfire
Continue to conduct current fuel
management programs and investigate and
apply new and emerging fuel management
techniques.

Fire/ Natural
Resources
Director/Parks
and
Recreation
10,000
to
50,000
FEMA and
Fire Safe
Council
grants
High 1 yr.

In progress. The Natural
Resource Manager has
taken lead on all fuel
management funds and
projects in the City
Open Space. Additional
grant funding has been
obtained to augment
allocated fuel
management budget.

SL.24 Wildfire Require an enhanced fire protection plan in Local Very High Fire Severity Zones. Fire Less than10,000 Staff
Time/ Dept.

Budget
Medium 1 yr. In progress.

SL.25 Biological Continue offering free flu vaccines to City employees.

Human
Resources
Less than
10,000
County
Program Medium
Annual
impleme
ntation
In progress. Continued
participation in the
County Public Health
Point of Distribution
program.

SL.26 Biological
Educate and encourage City employees to
maintain a healthy work environment by
utilizing sick and other leave benefits to avoid
coming to work when sick or contagious and
encouraging employees to develop plans for
caring for sick family members taking care of
ill family members.

Human
Resources
Little to
no cost
General
Fund Medium
Annual
impleme
ntation
In progress. Include in
ongoing wellness,
benefits, and leave of
absence training,
education, and general
communications.