City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Table of Contents
Chapter 1: Introduction Plan Purpose...... 1 Authorities...... 2 Plan Adoption ...... 3 Plan Use ...... 5 Mitigation Goals ...... 5 Hazard Mitigation Planning Process ...... 6 Public Engagement ...... 8 State and Federal Guidelines and Requirements for mitigation plans ...... 11 Use of Existing Data ...... 11 Public Review Draft ...... 15 Plan Revision and Adoption ...... 15 Plan Maintenance ...... 15 Continued Public Involvement ...... 18 Point of Contact ...... 18 Chapter 2: Community Profile History...... 19 Population and Demographics ...... 20 Vulnerable Populations ...... 22 Projected Population Growth ...... 28 Economic Trends ...... 28 Employment and Industry ...... 30 Transportation and Commuting Patterns ...... 32 Housing and Community Development...... 33 Existing Land Use ...... 34 Development Trends and Future Development ...... 38 Evacuation Routes ...... 39 Critical Facilities ...... 41 Chapter 3: Hazard Assessment Hazard Identification ...... 55 Climate Change Considerations ...... 58 Hazard Profiles...... 60 Summary of Vulnerability ...... 166 Hazard Prioritization ...... 171 Chapter 4: Hazard Mitigation Stratigy Overview ...... 175 Goals and Objectives of Hazard Mitigation...... 175 Hazard/Threat Assessment...... 177 Capabilities Assessment...... 177 Mitigation Actions ...... 183 FEMA National Flood Insurance Program ...... 201 Relationship to Other City Plans...... 202
August 2019 i
Page Left Blank Intentionally
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) CHAPTER 1: INTRODUCTION Natural hazards have existed throughout time and have a life cycle of occurrence. This cycle is matched by a series of emergency management phases: preparedness, response, recovery, and mitigation. However, when natural hazards such as earthquakes, floods, or windstorms are at their height, they pose severe risk to people and property. They can cause death, injuries, or displace people from their homes, cause significant damage to the community, businesses, public infrastructure, and environment, and cost tremendous amounts in terms of response and recovery dollars, further contributing to economic loss.
A successful hazard mitigation plan includes a strategy that enables the implementation and sustainment of local actions that reduce vulnerability and risk from hazards and reduces the severity of the effects of hazards on people and property. Historically, in many local jurisdictions, disasters are followed by repairs and reconstruction, which simply restore the area to pre-disaster conditions; however, the replication of pre‐disaster conditions results in a cycle of damage, reconstruction, and repeated damage. Such efforts may expedite a return to normalcy; hazard mitigation ensures that post‐disaster repairs and reconstruction results in a true reduction of future hazard vulnerability.
While disasters cannot be prevented from occurring, their effects can be reduced or eliminated through a mitigation strategy that includes a well‐organized public education and awareness effort, preparedness activities, and mitigation actions. For those hazards that cannot be fully mitigated, the community must be prepared to provide efficient and effective response and recovery. This Local Hazard Mitigation Plan (LHMP) outlines opportunities to increase San Juan Capistrano’s resiliency in the face of future natural hazards. PLAN PURPOSE Under the Robert T. Stafford Disaster Relief and Emergency Assistance Act (Public Law 93-288), as amended by the Disaster Mitigation Act of 2000, local governments are required to develop a hazard mitigation plan as a condition for receiving certain types of emergency and non-emergency disaster assistance, including funding for mitigation projects and emergency response. Local Hazard Mitigation Plans must be updated every five years. The City of San Juan Capistrano’s Local Hazard Mitigation Plan (LHMP) was previously approved by FEMA, dated July 20, 2007.
The purpose of this revision to the Local Hazard Mitigation Plan is to identify the City’s hazards, review and assess past disaster occurrences, estimate the probability of future occurrences, and set goals to mitigate potential risks to reduce or eliminate long-term risks to people and property from natural and man-made hazards.
The City of San Juan Capistrano’s disaster-mitigation strategy is on-going. The goal is to update and maintain a plan inclusive to nearby jurisdictions, special districts, businesses, and community organizations to promote a collaborative mitigation effort. The City’s planning process followed a methodology presented by the Federal Emergency Management Agency (FEMA) and the California Office of Emergency Services (Cal OES). The process included inviting officials and representatives from Federal, State, and local agencies, as well as, special districts, school districts, non-profit organizations, and the general public to participate in the planning process.
August 2019 1
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) AUTHORITIES Federal Emergency Management Agency (FEMA)
This plan complies with the Federal Disaster Mitigation Act (2000), Federal Register 44 CFR Parts 201 and 206, which modified the Robert T. Stafford Disaster Relief and Emergency Assistance Act by adding a new section, 322 - Mitigation Planning. This law, as of November 1, 2004, requires local governments to develop and submit hazard mitigation plans as a condition of receiving Hazard Mitigation Grant Program (HMGP) funding and other mitigation project grants.
Hazard mitigation planning is governed by the Stafford Act, as amended by the Disaster Mitigation Act of 2000 (DMA 2000), and by federal regulations implementing the Stafford Act. DMA 2000 revised the Stafford Act to require state, local, and tribal governments to develop and submit to FEMA a mitigation plan that outlines processes for identifying the natural hazards, risks, and vulnerabilities of the jurisdiction.
To implement the mitigation planning requirements of the Stafford Act, FEMA promulgated 44 CFR Part 201, the federal regulations governing the planning process, plan content, and the process for obtaining approval of the plan from FEMA. The planning requirements set forth in the CFR, including plan revision requirements, are identified through the FEMA Regulation Checklist in the Local Mitigation Plan Review Tool. State of California
In addition to the requirements listed above, the State of California has also enacted revisions to both California Government Code Sections 8685.9 and 65302.6 (commonly known as AB 2140 [Chaptered 2006]). Descriptions of these government code sections are provided below: California Government Code §8685.9 Notwithstanding any other provision of law, including Section 8686, for any eligible project, the state share shall not exceed 75 percent of total state eligible costs unless the local agency is located within a city, county, or city and county that has adopted a local hazard mitigation plan in accordance with the Federal Disaster Mitigation Act of 2000 (P.L. 106-390) as part of the safety element of its general plan adopted pursuant to subdivision (g) of Section 65302. In that situation, the Legislature may provide for a state share of local costs that exceeds 75 percent of total state eligible costs. California Government Code §65302.6 (a) A city, county, or a city and county may adopt with its safety element pursuant to subdivision (g) of Section 65302 a Local Hazard Mitigation Plan (LHMP) specified in the Federal Disaster Mitigation Act of 2000 (Public Law 106-390). The hazard mitigation plan shall include all of the following elements called for in the federal act requirements: (1) An initial earthquake performance evaluation of public facilities that provide essential services, shelter, and critical governmental functions. (2) An inventory of private facilities that are potentially hazardous, including, but not limited to, multiunit, soft story, concrete tilt-up, and concrete frame buildings. (3) A plan to reduce the potential risk to private and
August 2019 2
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) governmental facilities in the event of a disaster. (b) Local jurisdictions that have not adopted a local hazard mitigation plan shall be given preference by the Office of Emergency Services in recommending actions to be funded from the Pre-Disaster Mitigation Program, the Hazard Mitigation Grant Program, and the Flood Mitigation Assistance Program to assist the local jurisdiction in developing and adopting a local hazard mitigation plan, subject to available funding from the Federal Emergency Management Agency. California Government Code §65302 (g)(4) California Government Code Section 65302 (g)(4), also known as Senate Bill (SB) 379, requires that the safety element of a community’s general plan address the hazards created or exacerbated by climate change. The safety element must identify how climate change is expected to affect hazardous conditions in the community and must include measures to adapt and be more resilient to these anticipated changes. As the LHMP can be incorporated into the safety element, including these items in the LHMP can satisfy the state requirement. SB 379 requires climate change to be addressed in the safety element when the LHMP is updated after January 1, 2017 (for communities that already have an LHMP), or by January 1, 2022 (for communities without an LHMP). PLAN ADOPTION The plan is consistent with current standards and regulations and meets the requirements of both State and Federal guidelines.
The City of San Juan Capistrano will adopt the LHMP via a resolution of the City Council following plan approval from FEMA. Figure 1.1 is the resolution used to adopt the 2019 Local Hazard Mitigation Plan.
August 2019 3
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Figure 1.1: City of San Juan Capistrano 2019 Local Hazard Mitigation Plan Resolution (Add after adoption)
August 2019 4
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) PLAN USE Each section of the Plan provides information and resources to assist plan users in understanding the hazard-related issues facing residents, businesses, and the environment. The structure of the Plan enables users to review each section as needed and allows the City of San Juan Capistrano to review and update sections as new data becomes available. The ease of incorporating new data into the Plan will result in a Plan that remains current and relevant to San Juan Capistrano. The LHMP is composed of the following chapters:
Chapter 1: Introduction. The introduction describes the background and purpose of developing the Plan in addition to introducing the mitigation priorities; this chapter summarizes the planning process and provides information on plan implementation, monitoring, and evaluation. Chapter 2: Community Profile. The community profile presents the history, geography, demographics, and socioeconomics of San Juan Capistrano. It serves as a tool to provide a historical perspective of natural hazards in the city. Chapter 3: Hazards Assessment. This chapter provides information on hazard identification, hazard profiles, vulnerability and risks associated with natural and man-made hazards, and a vulnerability assessment of critical facilities in relation to the identified hazards. Chapter 4: Mitigation Actions. This chapter provides strategies and mitigation actions to reduce potential risks to San Juan Capistrano’s critical facilities, residents, and businesses. This chapter also discusses the assets and capabilities available to achieve the proposed mitigation actions, as well as opportunities for continued public involvement. MITIGATION GOALS The mission of the San Juan Capistrano LHMP is to promote sound public policy designed to protect citizens, critical facilities, infrastructure, private property, and the environment from natural hazards. This can be achieved by increasing public awareness, documenting the resources for risk reduction and loss prevention, and identifying activities to guide the City toward building a safer, more sustainable community. The goals are a guideline that represents what the community wants to accomplish through the Local Hazard Mitigation Plan. Goals are broad statements that represent a long-term, community- wide vision.
The following goals have been established for the San Juan Capistrano 2019 LHMP:
Protect Life and Property by making homes, businesses, infrastructure, critical facilities, and other property more resistant to natural hazards.
Increase Public Awareness through development and implementation of outreach programs focusing on the risks associated with natural and man-made hazards.
Improve Natural Systems by balancing watershed planning, natural resource management, and land use planning with natural hazard mitigation to protect life, property, and the environment.
August 2019 5
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Develop Partnerships by strengthening communication and coordinating participation among and within public agencies, residents, nonprofit organizations, businesses, and industries to gain a vested interest in implementation.
Enhance Emergency Services and Response through establishment of policies that promote mitigation projects to protect critical facilities, strengthen services, and harden infrastructure. HAZARD MITIGATION PLANNING PROCESS At the onset of the planning process, the City of San Juan Capistrano retained a consulting company to assist with the revision of the LHMP and invited the community and the public and private sectors to participate in the revision of the LHMP. This Plan is the result of a process involving City departments, stakeholder agencies, businesses, residents, and the community at large. Local Hazard Mitigation Planning Team (LHMP Team)
The LHMP team was comprised of the following City Departments and contract agencies:
Utilities Operations and Engineering Development Services Public Works Engineering Geographical Information Systems Specialist City Manager’s Office City Manager Emergency Management Human Resources Public Works Orange County Fire Authority Orange County Sheriff’s Department
Stakeholders included representation from the Southern California Regional Rail Authority, SCRRA/Metrolink, SCRRA/Compliance Office, Orange County Emergency Management, OC Health Care Agency, Southern California Edison, San Diego Gas and Electric, and OC Public Works.
The LHMP Team is responsible for the development, implementation, and maintenance of this Plan. At these meetings, team members, stakeholders, and members of the community discussed the objectives of the plan, identified the hazards that pose a threat to San Juan Capistrano, and prepared and reviewed mitigation strategies to reduce the City’s vulnerabilities. All stakeholders and the community were provided an opportunity to provide comments, input, and feedback on the plan. LHMP Schedule The LHMP Team convened meetings to guide development of the San Juan Capistrano Local Hazard Mitigation Plan. A planning schedule was developed, and five meetings were held to discuss preparation and development of the LHMP.
August 2019 6
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
The LHMP Team conducted the following meeting schedule:
Table 1.1: Schedule of Team Meetings Type of Meeting Date
LHMP Kickoff Meeting January 16, 2019
LHMP Team Meeting 1 February 26, 2019
LHMP Team Meeting 2 March 25, 2019
LHMP Team Meeting 3 May 20, 2019
LHMP Team Meeting 4 July 15, 2019
Table 1.2: Meeting Summaries Date Action
Project Kickoff Meeting-ELA provided an introduction to the project, discussed January 16, 2019 overarching goals for the effort, discussed communication protocols, and identified points of contact.
LHMP Meeting #1-The Team reviewed the LHMP process, identified hazards of concern, February 26, 2019 and finalized critical facilities list.
LHMP Meeting #2-The Team reviewed the hazard profiles. Discussed preliminary results of the risk assessment for each hazard and prioritized hazards with LHMP team March 25, 2019 members. A list of mitigation actions from the 2004 LHMP was presented for the team to evaluate and consider additional new action items.
LHMP Meeting #3-The Team evaluated all of the mitigation action items and performed May 20, 2019 the STAPLEE cost to benefit analysis of the new action items.
LHMP Meeting #4-The Team reviewed material and discussion points for the Public July 15, 2019 Meetings.
San Juan Capistrano staff collected data and compiled research on five hazards: earthquakes, earth movements (landslides), flooding, wildfires, and wind storms. Research materials came from federal agencies including FEMA, state agencies including Cal OES and Cal Fire, County of Orange and Orange County Fire Authority Hazard Mitigation Plan, and City level material such as the General Plan Safety Element. City staff conducted research by referencing historical local newspapers, interviewing long time City of San Juan Capistrano employees, and locating the City of San Juan Capistrano
August 2019 7
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) information in historical documents. City staff reviewed current mitigation activities and identified new mitigation actions. PUBLIC ENGAGEMENT Online Survey
As part of the public engagement and outreach process for the LHMP, the City created an Online Survey for community members. A link to the survey was placed on the City’s website, as well as distributed on the City Manager’s Weekly Update email. The survey asked about potential hazards facing San Juan Capistrano and what steps community members have taken, or are interested in taking, to reduce the threat from these hazards. The survey produced the following outcomes:
Table 1.3: Results of Online Survey for Community Members
When Asked, Participants Responded
How concerned are you about the following
hazards impacting the City of San Juan
Capistrano?
erned
Not Concerned Not Somewhat Conc Concerned VeryConcerned Extremely Concerned
Earthquakes and geologic hazards (landslides) 4.62% 29.23% 26.15% 30.77% 9.23%
Hazardous materials 9.38% 34.38% 25.00% 17.09% 14.06%
Terrorism 35.38% 35.38% 20.00% 6.15% 3.08%
Transportation incidents (air, rail, highway) 4.62% 32.31% 32.31% 16.92% 13.85%
Radiological accident 16.92% 33.85% 15.85% 20.00% 13.85%
Flooding 13.85% 20.00% 35.38% 21.45% 9.23%
Drought and water shortages 6.15% 21.45% 32.31% 29.23% 10.77%
Urban and wildland fires 1.54% 18.46% 38.46% 26.15% 15.38%
Severe weather and storms 16.92% 35.38% 23.08% 16.92% 7.69%
Public health epidemic or pandemic 16.92% 43.08% 20.00% 15.38% 4.62%
Climate change 26.56% 23.44% 23.44% 14.06% 12.50%
Civil unrest 41.54% 30.77% 16.92% 7.69% 3.08%
August 2019 8
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
When Asked, Participants Responded
How prepared is your household to cope
Not at Not all
prepared prepared prepared prepared
with a hazard event? Very well
Somewhat Adequately
Well prepared
1.54% 35.38% 29.23% 26.15% 7.69%
When Asked, Participants Responded
% who have Which of the following actions have you taken to prepare your household for a hazard taken that event? action
Prepared a disaster supply kit 78.64%
Stored water (one gallon per person per day) 81.54%
Stored non-perishable food 83.05%
Received First Aid/ CPR training 84.62%
Taken a Community Emergency Response Team (CERT) course 86.15%
Stored medical supplies (first aid kit, prescription medicines, over-the-counter medications) 73.85%
Created a home evacuation plan 36.92%
Designated a family meeting place 35.38%
Identified utility shut offs and know the location of needed tools 34.62%
Stored a battery-powered radio, flashlights, and extra batteries 78.46%
Installed smoke detectors on each level of your home 89.32%
Installed carbon monoxide detectors on each level of your home 80.00%
Have fire extinguishers in appropriate areas of the home 73.85%
Purchased flood insurance 23.08%
Purchased earthquake insurance 43.08%
A detailed summary of the online survey is included in Appendix: A.
August 2019 9
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) Public Engagement Workshops
The City of San Juan Capistrano staff and the LHMP Consultant facilitated two public workshops to gather comments, ideas, and recommendations from the City of San Juan Capistrano citizens about mitigation planning and priorities for the revision of the LHMP. These meetings were publicized using the City’s standard protocol, which involved publication in the City Manager’s Newsletter, distribution of flyers publicizing the LHMP workshops at the libraries and other public forums, and announcements on the City’s website and social media sites. Comments and recommendations from the community were incorporated into the LHMP as appropriate.
Table 1.4: Summary of Public Outreach/Involvement Meeting and Presentations Date Summary
Large Animal Response Team (LART) Meeting: An overview of the LHMP was provided and July 10, 2019 feedback requested as part of their Sumer Lecture Series.
Orange County Emergency Management Organization (OCEMO): On July 11, 2019, the LHMP was discussed in a public forum at the OCEMO meeting where participation and July 11, 2019 comments were invited. Members of OCEMO include representation from the 34 cities in Orange County, State Regional Representatives, American Red Cross, OC Health Care Agency, and other representatives from special districts in the County.
Public Meeting held in the City Council Chambers at 10:00 am. July 15, 2019 No comments were received
Public meeting held in the City Council Chambers at 1:00 pm. July 15, 2019 Comments included questions regarding mold in public buildings, liquefaction zones, and areas susceptible to multiple hazards.
A copy of the meeting agenda, presentation, sign-in sheets, and notes from these meetings are provided in Appendix: B.
August 2019 10
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) STATE AND FEDERAL GUIDELINES AND REQUIREMENTS FOR MITIGATION PLANS The City of San Juan Capistrano followed the state and federal guidelines for developing and revising Local Hazard Mitigation Plans.
Following are the Federal requirements for approval of a Natural Hazard Mitigation Plan in which the City of Capistrano followed: Open public involvement with public meetings that introduced the process and project requirements to revise the LHMP The public was afforded opportunities for involvement in identifying and assessing risk, suggesting mitigation actions, reviewing draft documents, and approving of the Plan Community participation was encouraged with local government agencies, the business community, educational institutions, and non-profits Incorporation of local documents, including the City's General Plan, Zoning Ordinance, the Building Codes, and other pertinent documents as appropriate The revision of the LHMP included the following components in the planning process: Complete documentation of the planning process A detailed risk assessment on hazard exposures in the community A comprehensive mitigation strategy, which describes the goals & objectives, including proposed strategies, programs, and actions to avoid long-term vulnerabilities A plan maintenance process, which describes the method and schedule of monitoring, evaluating, and updating the Plan and integration of the Local Hazard Mitigation Plan into other planning mechanisms Plan Review and Approval by both State OES and FEMA Formal adoption by the City Council These requirements are spelled out in greater detail in the following chapters, sections, and supporting documentation. USE OF EXISTING DATA
The LHMP Planning Team used a number of different plans, studies, technical reports, data sets, and other resources to prepare the hazard assessment, mapping, hazard profiles, and other components of this Plan. Table 1.5 shows the sections of the LHMP and the corresponding plans, studies, technical reports, and websites used to revise the plan.
August 2019 11
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Table 1.5: Plans, Studies, Technical Reports, and Websites Used to Develop the Plan Plans, Studies, Technical Reports, and Websites Used Throughout the Plan
City of San Juan Capistrano General Plan (December 1999, Amended 2002)
City of San Juan Capistrano Municipal Code
City of San Juan Capistrano Natural Hazard Mitigation Plan 2004 (Adopted 2007) Southern California Association of Governments’ (SCAG), Profile of the City of San Juan Capistrano, Local Profiles Report 2017 City of San Juan Capistrano 2014-2021 Housing Element, Adopted January 21, 2014/Revised September 19, 2017 City of San Juan Capistrano, California “Preserving the Past to Enhance the Future” Comprehensive Annual Financial Report for the Fiscal Year Ended June 30, 2018
California Department of Finance, E-5, 2016
Orange County Emergency Operations Plan 2015
County of Orange and Orange County Fire Authority Hazard Mitigation Plan (November 2015)
Orange County Essential Facilities Risk Assessment (OCEFRA) Project Report (April 2009)
State of California Emergency Plan October 1, 2017
California State Hazard Mitigation Plan, 2018 (SHMP)
California Department of Finance, E-5, 2016
FEMA Local Mitigation Plan Review Guide 2011
FEMA Local Mitigation Planning Handbook 2013 California Governor’s Office of Planning and Research, Defining Vulnerable Communities in the Context of Climate Adaptation Resource Guide July 2018 County of Orange San Onofre Nuclear Generating Station Emergency Operations Plan 2018
California Code of Regulations
Plans, Studies, Technical Reports, and Websites Used in Chapter 2: Community Profile
2000 U.S. Decennial Census; 2010 U.S. Census American Community Survey; and Nielsen Co., 2016
Census American Community Survey; Nielsen Co., 2016
http://dof.ca.gov/Reports/Demographic_Reports/American_Community_Survey/
https://datausa.io/profile/geo/san-juan-capistrano-ca/#intro
http://factfinder.census.gov
August 2019 12
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Plans, Studies, Technical Reports, and Websites Used in Chapter 3: Hazards Assessment
American Association for the Advancement of Science (AAAS), Union of Two Faults, Julian Lozos, Cal State Northridge, Science Advances BNSF Railway 2015 Annual Review Report Cal EMA Regional Information Management System (RIMS) Spill Database, https://www.caloes.ca.gov/for- individuals-families/hazardous-materials/spill-release-reporting
California Adaptation Planning Guide (September 2012)
California Coastal Commission, Natural History of Fire & Flood Cycles, Prepared by Jack Ainsworth & Troy Alan Doss as a presentation to the Post-Fire Hazard Assessment Planning and Mitigation Workshop at the University of California, Santa Barbara, August 18, 1995
California Department of Forestry and Fire Protection (CAL FIRE)
California Public Health Department – Influenza (2015)
City of San Juan Capistrano Municipal Code, Chap 11. Floodplain Management Regulations
H. McCann and C. Chappelle, “Drought Bills: Small Changes, High Impact” (PPIC blog, June 30, 2015)
http://droughtmonitor.unl.edu/data/pdf/current/current_ca
http://earthquake.usgs.gov/ http://earthquake.usgs.gov/ earthquakes/states/California/history.php, U.S.G.S. Earthquake Hazards Program data http://earthquake.usgs.gov/earthquakes/states/historical_state.php#california
http://geochange.er.usgs.gov/sw/impacts/hydrology/state_fd/cawater1.html;
http://maps.conservation.ca.gov/cgs/informationwarehouse/
http://pubs.usgs.gov, U.S.G.S. Fact Sheet 2008-3027
http://www.californiadrought.org/drought/background/
http://www.caloes.ca.gov/ICESite/Pages/Drought.aspx
http://www.cdph.ca.gov/Programs/CID/DCDC
http://www.flu.gov/about_the_flu/h5n1/index.html http://www.ldeo.columbia.edu/res/div/ocp/pub/cook/2009_Cook_IPCC_paleo-drought.pdf; CA Department of Water Resources. 2010
http://www.ncdc.noaa.gov/monitoring-references/dyk/drought-definition http://www.nrdc.org/climate-change-and-health-extreme-heat#/map/detail/CA. National Resources Defense Council http://www.ocgov.com/about/emergency/terrorism
http://www.ochealthinfo.com/gov/health/phs/about/dcepi/epi/azdiseases/measles.asp
August 2019 13
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Plans, Studies, Technical Reports, and Websites Used in Chapter 3: Hazards Assessment
http://www.ochealthinfo.com/gov/health/phs/about/dcepi/epi/dip/prevention/disease_listing_a_z
http://www.ochealthinfo.com/phs/about/dcepi/epi/dip/prevention/disease_listing_a_z/zika https:// weather.com/forecast/regional/news/2018-07-03-southern-california-record-heat-southwest-monsoon- moisture https://www.sciencemag.org/news/2017/06/here-s-how-much-climate-change-going-cost-your-county
https://ca.water.usgs.gov/california-drought/california-drought-comparisons.html)
https://cal-adapt.org/tools/extreme-heat
https://calepa.ca.gov/cupa/ereporting/ https://geochange.er.usgs.gov/sw/impacts/hydrology/state_fd/cawater1.html, Major Floods and Droughts in California (1990) https://weather-and-climate.com
https://www.cdc.gov/flu/index.htm
https://www.cdc.gov/westnile/
https://www.epa.gov/climate-research
https://www.fema.gov/hazus-mh-earthquake-model
https://www.usgs.gov/faqs/what-are-tsunamis?qt-news_science_products=0#qt-news_science_products, USGS, Science for a Changing World, Natural Hazards, What are Tsunamis? Multicentury Evaluation of Recovery from Strong Precipitation Deficits in California, Eugene R. Wahl, NOAA/National Centers for Environmental Information, Boulder, Colorado NASA, Global Climate Change, Vital Signs of the Planet, https://climate.nasa.gov/climate_resources/24/graphic- the-relentless-rise-of-carbon-dioxide/ National Oceanic and Atmospheric Administration
National Weather Service, “A History of Significant Weather Events in Southern California Organized by Weather Type” 2017 Preparing California for Extreme Heat: Guidance and Recommendations, Heat Adaptation Workgroup, a subcommittee of the Public Health Workgroup, California Climate Action Team (CAT), October 2013 Proceedings of the National Academy of Sciences “Perception of climate change” James Hansen, Makiko Sato, Reto Ruedy Public Policy Institute of California, “What if California’s Drought Continues”, Recent Trends in Northern and Southern Hemispheric Cold and Warm Pockets, Richard Grumm and Anne Balogh, National Weather Service and Penn State University Safeguarding California: Implementation Action Plans, Emergency Management Sector Plan
San Juan Capistrano Urban Water Management Plan (2015)
August 2019 14
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Plans, Studies, Technical Reports, and Websites Used in Chapter 3: Hazards Assessment
Southern California Earthquake Date Center, Significant Earthquakes and Faults, Historical Earthquakes & Significant Faults in Southern CA Summary Report of the Orange County Health Care Agency Response to Pandemic H1N1 2009 Influenza
U.S.G.S. Richter Scale and Modified Mercalli Intensity Scale (2014)
US DOT National Pipeline Mapping System Public Viewer
USGS Earthquake Hazards Program Data
Plans, Studies, Technical Reports, and Websites Used in Chapter 4: Hazard Mitigation
FEMA National Flood Insurance Program (NFIP) FEMA How-to Guides #3 and #5 (386-3 and 386-5), STAPLE/E criteria (Social, Technical, Administrative, Political, Legal, Economic, and Environmental)
PUBLIC REVIEW DRAFT The Draft LHMP was completed and released to the general public for a 30-day public review and comment period on September 1-30, 2019. The Draft LHMP was provided for review at the City Clerk’s office. PLAN REVISION AND ADOPTION Following public review and comments, the LHMP Planning Team revised the Draft Plan, and the City of San Juan Capistrano submitted it to Cal OES and FEMA for review and approval. The LHMP Team then made additional revisions to incorporate comments from state and federal agencies, as appropriate, and submitted the final draft to City of San Juan Capistrano decision makers. The San Juan Capistrano City Council adopted the final LHMP on [Insert Adoption Date], 2019. PLAN MAINTENANCE Section 201.6(c)(4) of Title 44 of the Code of Federal Regulations requires that a hazard mitigation plan must detail the formal process that will ensure that the Plan remains an active and relevant document and that the planning partners maintain their eligibility for applicable funding sources. This section describes the Plan maintenance process, includes a schedule for monitoring and evaluating the Plan annually, and describes how an updated Plan will be produced every five years. This section also describes how public participation will be integrated throughout the plan maintenance and implementation process. It also explains how the mitigation strategies outlined in this Plan will be incorporated into existing planning mechanisms and programs, such as comprehensive land-use planning processes, capital improvement planning, and building code enforcement and implementation. The Plan’s format allows sections to be reviewed and updated when new data become available, resulting in a Plan that will remain current and relevant.
August 2019 15
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) Coordinating Body
The LHMP team will be responsible for the maintenance of this LHMP. The San Juan Capistrano Emergency Services Manager will coordinate maintenance of this Plan, the formal review process and the future updates. Key City departments’ heads and staff positions are identified below:
City Clerk City Manager Assistant City Manager Senior Management Analyst Development Services Director Community Services Director Chief Financial Officer Fire Chief Emergency Services Manager Human Resources Manager Police Chief Public Works and Utilities Director
The San Juan Capistrano Emergency Services Manager will facilitate the LHMP team meetings and will assign tasks such as updating and presenting the Plan to other departments, stakeholder groups, and/or elected officials. Plan implementation and evaluation will be a shared responsibility among all LHMP team members. Adoption
Section 201.6(c)(5) of Title 44 of the Code of Federal Regulations requires that a hazard mitigation plan must document that it has been formally adopted by the governing body of the jurisdiction requesting federal approval of the Plan. Jurisdiction requesting approval must document that it has been formally adopted. This Plan will be submitted for a pre-adoption review to Cal OES and FEMA Region IX prior to adoption. Once pre-adoption approval has been provided, the San Juan Capistrano City Council is responsible for final adoption of the Plan. Disaster Mitigation Act (DMA) compliance and its benefits cannot be achieved until the Plan is adopted. Once the Plan has been adopted, the City will be responsible for transmitting the adopted version to FEMA for their records. Annual Review and Evaluation
The minimum task of the annual LHMP team meeting will be the evaluation of the progress of the Plan and incorporating the actions into other planning documents. These annual meetings will commence in 2020 and will be conduct during the month of April, in conjunction with departmental budget planning for the next fiscal year. This cycle may be accelerated to less than five years based on the following triggers: A presidential disaster declaration that impacts the City of San Juan Capistrano A hazard event that causes loss of life
August 2019 16
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
This review will include the following:
Summary of any hazard events that occurred during the prior year and their impacts on the community Review of successful mitigation initiatives identified in the Plan Brief discussion about why targeted mitigation strategies were not completed Reevaluation of the mitigation actions to determine if the timeline for identified projects needs to be amended (such as changing a long-term project to a short-term project due to funding availability) Recommendations for new mitigation actions Changes in, or potential for, new funding options/grant opportunities Integration of new GIS data and maps that can be used to inform the Plan Evaluation of any other planning programs or initiatives within the city that involve hazard mitigation The City will create a template to guide the LHMP team in preparing a progress report. The City will also prepare a formal annual report on the progress of the LHMP. This report will be used as follows:
Distributed to City department heads for review Posted on the City website on the page dedicated to the Plan, with the ability for the public to provide comments Provided to the local media through a press release Presented in the form of a council report to the City Council Plan Updates Section 201.6(d)(3) of Title 44 of the Code of Federal Regulations requires that local hazard mitigation plans be reviewed, revised if appropriate, and resubmitted for approval in order to remain eligible for benefits awarded under the DMA. The City intends to update the Plan on a five-year cycle from the date of initial Plan adoption. It is anticipated that this update process will occur one year prior to expiration of the existing Plan. Implementation through Existing Programs
The effectiveness of the City’s non-regulatory LHMP depends on the implementation of the Plan and incorporation of the outlined mitigation action items into existing City plans, policies, and programs. The Plan includes a range of action items that, if implemented, would reduce loss from hazardous events in the city. Together, the mitigation action items in the Plan provide the framework for activities that the City can choose to implement over the next five years. The City has prioritized the Plan’s goals and identified actions that will be implemented (resources permitting) through existing plans, policies, and programs.
The San Juan Capistrano City Manager has the responsibility of overseeing the Plan’s implementation and maintenance through the City’s existing programs. The Emergency Services Manager, or designated appointee, will assume lead responsibility for facilitating the LHMP implementation and maintenance meetings.
August 2019 17
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Although the City Manager will have primary responsibility for review, coordination, and promotion, the Plan implementation and evaluation of the Plan will be a shared responsibility among all departments.
The information on hazards, risk, vulnerability, and mitigation contained in this Plan is based on the best information and technology available at the time the LHMP was prepared. As previously stated, the City’s General Plan is considered to be an integral part of this Plan. The City, through adoption of its General Plan Safety Element goals, has planned for the impact of natural hazards. The LHMP process has allowed the City to review and expand upon the policies contained within the General Plan Safety Element. The City views the General Plan and the LHMP as complementary planning documents that work together to achieve the ultimate goal of the reduction of risk exposure to the citizens of San Juan Capistrano. Many of the ongoing recommendations identified in the mitigation strategy are programs recommended by the General Plan and other adopted plans. The City will coordinate the recommendations of the LHMP with other planning processes and programs including the following:
Capital Improvements Program Building Codes Emergency Operations Plan General Plan CONTINUED PUBLIC INVOLVEMENT
The public will continue to be apprised of the LHMP actions through City standard protocols. POINT OF CONTACT Preparation and future update of the City’s Local Hazard Mitigation Plan will be the responsibility of the City’s Emergency Services Manager: City of San Juan Capistrano (949) 493-1171.
August 2019 18
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) CHAPTER 2: COMMUNITY PROFILE
The City of San Juan Capistrano is located in Orange County Region I, Southern Administrative Region of State Office of Emergency Services. It covers an area of approximately 13.6 square miles and has a population of approximately 36,000 people. It is situated in a coastal valley approximately 1.5 miles inland from the Pacific Ocean, approximately 62 miles south of the City of Los Angeles, and 65 miles north of the City of San Diego. The City is bordered by the following jurisdictions: City of Mission Viejo to the north, the unincorporated section of Orange County to the east, the City of Laguna Niguel to the west, the City of Dana Point to the southwest, and the City of San Clemente to the southeast. HISTORY The City of San Juan Capistrano is a unique community grounded in a history of Native American culture. In 1775, Spanish Viceroy Bucareli directed that the next new mission be established in Alta California (Upper California) would be named in honor of San Juan Capistrano (Saint John Capistrano, 1385-1456). The saint, although a priest, became a war hero when defending Vienna against the Turks. The mission was first established here in 1775 and formally dedicated by Father Serra in 1776. Father Serra named the mission San Juan Capistrano de Quanis-savit. The community that ultimately grew up around it adopted the mission's short name.
San Juan Capistrano was officially incorporated as a city in 1961. The council- manager form of government, with five elected council members elected citywide, direct the city operations and municipal services. The City has grown from a small community of approximately 1,200 residents, when it was incorporated in 1961, to a developed city of approximately 36,000 in 2017, with a variety of land uses providing open space, recreation, housing, jobs, shopping, and services. The City prides itself on effectively maintaining its open space character by acquiring land to preserve its defining ridgelines, hillsides, and trails. The City is predominantly residential, with a mix of commercial, industrial, agricultural, and tourist-oriented uses. The underlying philosophy of the city is to encourage and preserve its present character as a small, self- contained, village-like community with abundant open space.
August 2019 19
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) POPULATION AND DEMOGRAPHICS Over the years, the City of San Juan Capistrano has experienced a great deal of in-fill development, which is increasing the population density creating greater service loads on the built infrastructure, including roads, water supply, sewer services, and storm drains.
The following tables and graphs provide statistics for specific demographics:
Table 2.1: City of San Juan Capistrano Population1 Percent of Type of Population Population 36,064 Total Population estimated July 1, 2017 Males 48.5% Females 51.5% Persons under 5 years, April 1, 2010 6.2% Persons under 18 years, April 1, 2010 24% Persons 65 years and over, April 1, 71.1% 2010
Table 2.2: City of San Juan Capistrano Race and Ethnicity2 Race and Ethnicity Percent of Population White (non-Hispanic) 57.5% Black 0.5% American Indian 1.2% Asian 2.8% Pacific Islander 0.1% Hispanic or Latino (of any race) 37.1% Two or More Races 4.0%
Table 2.3: City of San Juan Capistrano Educational, Health, and Economy3 Education, Health, and Economy Percent of Population High School Graduate 83.3% Bachelor Degree 36.9% With a disability, under age 65 years, percent, 2012-2016 5.4% In civilian labor force, total, percent of population age 16 years+, 2012-2016 54.2% Median household income (in 2016 dollars), 2012-2016 $79,393 Persons in poverty, percent 14.2%
1 United States Census Bureau, www.census.gov/quickfacts/fact/table/ (Accessed February 12, 2019) 2 United States Census Bureau, www.census.gov/quickfacts/fact/table/ (Accessed February 12, 2019) 3 United States Census Bureau, www.census.gov/quickfacts/fact/table/ (Accessed February 12, 2019)
August 2019 20
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Table 2.4: Poverty Status 2013-2017 San Juan Capistrano4 San Juan Capistrano, California Total Below poverty level Percent below poverty level Poverty Level Margin of Margin of Estimate Estimate Estimate Margin of Error Error Error
Population for whom poverty 35,914 +/-58 4,095 +/-1,011 11.4% +/-2.8 status is determined
Under 18 years 8,380 +/-639 1,341 +/-541 16.0% +/-6.2
Under 5 years 2,259 +/-428 419 +/-251 18.5% +/-10.2
5 to 17 years 6,121 +/-615 922 +/-415 15.1% +/-6.3
Related children of householder 8,366 +/-641 1,327 +/-540 15.9% +/-6.2 under 18 years
18 to 64 years 20,941 +/-610 2,254 +/-527 10.8% +/-2.5
18 to 34 years 6,822 +/-608 1,049 +/-309 15.4% +/-4.3
35 to 64 years 14,119 +/-622 1,205 +/-374 8.5% +/-2.6
60 years and over 8,781 +/-600 669 +/-188 7.6% +/-2.1
65 years and over 6,593 +/-492 500 +/-181 7.6% +/-2.7
Table 2.5: Health and Insurance Status 2013-20175 Health and Insurance Percent With a disability, under age 65 years 5.4% Persons without health insurance, under age 65 14.6%
Graph 2.1: Population of San Juan Capistrano by Age: 2000, 2010, 20166
4 U.S. Census Bureau American Community Survey, 2015; Nielsen Co.; California Department of Finance E-5, May 2016; CoreLogic/DataQuick; California Department of Education 5 U.S. Census Bureau American Community Survey, 2015; Nielsen Co.; California Department of Finance E-5, May 2016; CoreLogic/DataQuick; California Department of Education 6 2000 and 2010 U.S. Decennial Census; Nielsen Co., 2016
August 2019 21
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) VULNERABLE POPULATIONS The City of San Juan Capistrano’s vulnerable populations, include seniors, disabled citizens, women and children, as well as those people living in poverty who may be disproportionately impacted by natural hazards.
The City of San Juan Capistrano has identified various locations of potentially vulnerable populations. These locations have been mapped in relation to known hazard areas or zones. Information from that analysis was used in considering new mitigation action items. Table 2.6 lists the site within the City that house and care for segments of the population that are considered vulnerable in a disaster.
Table 2.6: Vulnerable Population Sites in San Juan Capistrano
Hazard
Address Description
Flood
Designator
Hazmat
Landslide
Fire Zone Liquefaction
31641 Rancho Viejo Rd / 27271 Paseo A Senior Apartments No No Yes No None Espada / 27221 Paseo Espada B 31741 Rancho Viejo Rd Senior Care Facility Yes No Yes No None C 27231 Calle Arroyo Disabled Adult Care Facility Yes No Yes No None D 27703 Ortega Highway Senior Mobile Home Park No Yes No No Very High 26508-26613 Mission St / 26571-26591 E Affordable Housing Community Yes No Yes Yes High Ramos St / 31646-31682 Ramos Way F 32200 Del Obispo St Senior Care Facility No No Yes No Moderate G 32371 Alipaz St Senior Mobile Home Park No No Yes Yes None H 26410-26506 Calle Rolando Affordable Housing Community Yes No Yes Yes None I 32353 San Juan Creek Road Senior Care Facility Yes No Yes No None J 26000 Avenida Aeropuerto Senior Mobile Home Park Yes No Yes Yes Moderate K 33831 Camino Capistrano Senior Mobile Home Park Yes Yes Yes Yes High L 34101 Via California Senior Condos No Yes No No High M Tract 5541 Senior Condos No No Yes No High N 30311 Camino Capistrano Senior Care Facility No No Yes Yes High O 27221 Paseo Espada Senior Apartments No No No No None P 31451 Avenida Los Cerittos Assisted Care Facility No No No No None Q 30333 Camino Capistrano Senior Apartments Yes No Yes Yes High
Map 2.1 shows the seven vulnerable population sites located within a 100 year flood zone. Map 2.2 shows the three vulnerable population sites located within a zone susceptible to landslides. Map 2.3 shows the 12 vulnerable population sites located within a zone susceptible to Liquefaction. Map 2.4 shows the six vulnerable population sites located within a 1,000 feet of a hazardous materials location. Map 2.5 shows the vulnerable population sites located in relationship to their wildland fire severity hazard.
August 2019 22 City of San Juan Capistrano Local Hazard Mitigation Plan Map 2.1: Vulnerable Population Sites Located Within a 100 year Flood Zone
Letter Name Address B Brookdale San Juan Capistrano 31741 Rancho Viejo Road C Casa De Amma 27231 Calle Arroyo 26508-26613 Mission St. / E Little Hollywood 26571-26591 Ramos St. / 31646-31682 Ramos Way H Calle Rolando Villas 26410-26506 Calle Rolando I Atria San Juan 32353 San Juan Creek Road J Capistrano Mobile Home Estates 26000 Avenida Aeropuerto K Villa San Juan Mobile Home Park 33831 Camino Capistrano Q The Groves 30333 Camino Capistrano
August 2019 23 City of San Juan Capistrano Local Hazard Mitigation Plan Map 2.2: Vulnerable Population Sites Located Within Landslide Susceptible Zones
Letter Name Address D El Nido Mobile Home Park 27703 Ortega Highway K Villa San Juan Mobile Home Park 33831 Camino Capistrano L Cancun Racquet Club 341091 Via California
August 2019 24 City of San Juan Capistrano Local Hazard Mitigation Plan Map 2.3: Vulnerable Population Sites Located Within Liquefaction Zones
Letter Name Address 31641 Rancho Viejo Rd / A Seasons Apartments 27271 Paseo Espada / 27221 Paseo Espada B Brookdale San Juan Capistrano 31741 Rancho Viejo Rd C Casa De Amma 27231 Calle Arroyo 26508-26613 Mission St / E Little Hollywood 26571-26591 Ramos St / 31646-31682 Ramos Wy F Del Obispo Terrace 32200 Del Obispo St G San Juan Mobile Estates 32371 Alipaz St H Calle Rolando Villas 26410-26506 Calle Rolando I Atria San Juan 32353 San Juan Creek Road Capistrano Valley Mobile Home J 26000 Avenida Aeropuerto Estates K Villa San Juan Mobile Home Park 33831 Camino Capistrano M San Juan Hills West Tract 5541 N Silverado Senior Living 30311 Camino Capistrano Q The Groves 30333 Camino Capistrano
August 2019 25 City of San Juan Capistrano Local Hazard Mitigation Plan Map 2.4: Vulnerable Population Sites Located within 1,000 ft. of a Hazardous Materials Location
Letter Name Address 26508-26613 Mission St / E Little Hollywood 26571-26591 Ramos St / 31646-31682 Ramos Wy G San Juan Mobile Estates 32371 Alipaz St H Calle Rolando Villas 26410-26506 Calle Rolando Capistrano Valley Mobile Home J 26000 Avenida Aeropuerto Estates K Villa San Juan Mobile Home Park 33831 Camino Capistrano N Silverado Senior Living 30311 Camino Capistrano Q The Groves 30333 Camino Capistrano
August 2019 26 City of San Juan Capistrano Local Hazard Mitigation Plan Map 2.5: Vulnerable Population sites Located in Relationship to their Wildland Fire Severity Hazard
Letter Name Address Zone D El Nido Mobile Home Park 27703 Ortega Highway Very High
26508-26613 Mission St / E Little Hollywood 26571-26591 Ramos St / High 31646-31682 Ramos Wy
F Del Obispo Terrace 32200 Del Obispo St. Moderate Capistrano Valley Mobile J 26000 Avenida Aeropuerto Moderate Home Estates Villa San Juan Mobile K 33831 Camino Capistrano High Home Park L Cancun Racquest Club 34101 Via California High M San Juan Hills West Track 5541 High N Silverado Senior Living 30311 Camino Capistrano High Q The Groves 30333 Camino Capistrano High
August 2019 27
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
PROJECTED POPULATION GROWTH While both Orange County and the City of San Juan Capistrano are expected to experience more growth during the next 30 years, future growth will be significantly lower than past growth. Graph 2.2 compares projected population growth in the City of San Juan Capistrano to nearby southern Orange County cities and the County as a whole. Between 2008 and 2035, Orange County is expected to grow by 14.5 percent, a gain of 432,000 new residents. According to the forecasts made by SCAG for the Southern California region, San Juan Capistrano is forecasted to grow by 9.9 percent during that same time period, which would be a gain of 3,400 new residents.7
Graph 2.2: Percent Change in Population South Orange County Cities and Orange County, 2000 – 20108
ECONOMIC TRENDS The economy of San Juan Capistrano employs 16,418 people and is specialized in administrative support, waste management services, real estate, rental and leasing, and professional, scientific tech services, which employ respectively 1.97, 1.92, and 1.57 times more people than what would be expected in a location of this size. The largest industries in San Juan Capistrano are professional, scientific, tech services (1,833), retail trade (1,827), and accommodation and food service (1,698), and the highest paying industries are professional, scientific, tech services ($66,583), utilities ($63,804), and
7 City of San Juan Capistrano 2014-2021 Housing Element, Adopted January 21, 2014/Revised September 19, 2017 8 E-4 Population Estimates for Cities, Counties, and the State, 2001–2010, with 2000 & 2010 Census Counts
August 2019 28
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) transportation and warehousing ($63,409). The median property value in San Juan Capistrano, California is $590,500, and the homeownership rate is 74.6%.9
Table 2.7 and Graph 2.3 represent the overall economy and revenue sources:
Table 2.7: City of San Juan Capistrano’s Overall Economy10 Economic Indicators San Juan Capistrano United States
Unemployment Rate 4.9% 5.2%
Recent Job Growth 2.3% 1.6%
Future Job Growth 39.6% 38.0%
Sales Taxes 8.0% 6.0%
Income Taxes 0.08% 0.046%
Income per Capita $37,917 $28,555
Household Income $72,568 $53,482
Family Median Income $82,399 $65,443
Graph 2.3: Revenue Sources11
9 https://datausa.io/profile/geo/san-juan-capistrano-ca/#intro (accessed February 12/2019) 10 Southern California Association of Governments’ (SCAG), Profile of the City of San Juan Capistrano, Local Profiles Report 2017 11 City of San Juan Capistrano, California “Preserving the Past to Enhance the Future” Comprehensive Annual Financial Report for the Fiscal Year Ended June 30, 2018
August 2019 29
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) EMPLOYMENT AND INDUSTRY Mitigation activities are needed at the business level to ensure the safety and welfare of workers and limit damage to industrial infrastructure. Employees are highly mobile, commuting from surrounding areas to industrial and business centers. This creates a greater dependency on roads, communications, accessibility, and emergency plans to reunite people with their families. Before a natural hazardous event, large and small businesses can develop strategies to prepare for natural hazards, respond efficiently, and prevent loss of life and property. Table 2.7, 2.8, and Graph 2.4 represent the types of major employers in the City.
Table 2.8: City of San Juan Capistrano’s Top Employers12 Rank Employer Employees % of Total City Employment
1 Capistrano Unified School District 954 5.48%
2 St. Margaret's Episcopal School 429 2.47%
3 Costco Wholesale 188 1.08%
4 Brookdale San Juan Capistrano 176 1.01%
5 Junipero Serra Catholic High School 150 0.86%
6 Mission Of San Juan Capistrano 149 0.86%
7 Fluidmaster 136 0.78%
8 Aquatic Technologies 114 0.66%
9 Silverado Senior Living 96 0.55%
10 Emerald Expositions Events Inc HQ 91 0.52%
Table 2.9: City of San Juan Capistrano’s Population by Occupation13 Occupation San Juan Capistrano United States
Agriculture, forestry, fishing, hunting 0.7% 1.3%
Mining, quarrying, oil and gas extraction 0.3% 0.6%
Construction 8.0% 6.2%
Manufacturing 7.6% 10.4%
Wholesale trade 2.3% 2.7%
12 City of San Juan Capistrano, California “Preserving the Past to Enhance the Future” Comprehensive Annual Financial Report for the Fiscal Year Ended June 30, 2018 13 Southern California Association of Governments’ (SCAG), Profile of the City of San Juan Capistrano, Local Profiles Report 2017
August 2019 30
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Occupation San Juan Capistrano United States
Retail trade 11.6% 11.6%
Transportation and warehousing 2.1% 4.1%
Information 2.6% 2.1%
Finance and insurance 3.6% 4.7%
Real estate, rental, leasing 3.3% 1.9%
Professional, scientific, technical services 11.6% 6.7%
Management of companies 0.0% 0.1%
Administrative, support, waste mgt svcs 8.6% 4.3%
Educational services 6.7% 9.3%
Health care and social assistance 9.8% 13.8%
Arts, entertainment, recreation 1.4% 2.2%
Accommodation, food services 10.1% 7.4%
Other services 7.3% 4.9%
Public administration 1.6% 4.8%
August 2019 31
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Graph 2.4: Jobs by Sector in San Juan Capistrano 201514
TRANSPORTATION AND COMMUTING PATTERNS
Over the past decade, the Orange County area experienced rapid growth in employment and population. There has been a constant increase in vehicle licensing transactions in the Orange County region. Between 2000 and 2016, the greatest change occurred in the percentage of individuals who traveled to work by public transit; this share decreased by 1.4 percentage points15as illustrated in Graph 2.5.
Graph 2.5: Journey to Work for Residents, Transportation Mode Choice: 2000, 2010, 2016
Other’ refers to bicycle, pedestrian, and home-based employment.
14 California Employment Development Department, 2016; InfoGroup 15 2000 U.S. Decennial Census; 2010 U.S. Census American Community Survey; and Nielsen Co., 2016
August 2019 32
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) HOUSING AND COMMUNITY DEVELOPMENT In the City of San Juan Capistrano, the demand for housing outstrips the available supply, and the recent low interest rates have further fueled the demand. Demand for available housing is extremely high with few existing homes available. Demand for low to medium priced homes continues to be strong.
Between 2000 and 2016, the median home sales price of existing homes in San Juan Capistrano increased 182 percent from $275,500 to $776,250. In 2016, the median home sales price in the city was $776,250, which was $131,250 higher than that in the county overall, as identified in Graph 2.6.
Graph 2.6: Median Home Sales Prices for Existing Homes: 2000-2016 (in $ thousands)16
(Note: Median home sales price reflects resale of existing homes, which varies due to type of units sold.)
The following lists table housing types and numbers of units:
Table 2.10: Housing Types by Units17 Housing Type Number of Units Percent of Total Units
Single Family Detached 6,642 54.2%
Single Family Attached 2,362 19.3%
Multi-family: 2 to 4 units 795 6.5%
Multi-family: 5 units plus 1,079 8.8%
Mobile Home 1,384 11.3%
Total 12,262 100%
16 Profile of the City of San Juan Capistrano Southern California Association of Governments’ (SCAG) 17 California Department of Finance, E-5, 2016
August 2019 33
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
The following table illustrates the age of the hosing stock:
Graph 2.7: Age of Housing Stock: 201618
EXISTING LAND USE The Land Use Element of the City of San Juan Capistrano’s General Plan (December 1999, Amended 2002) is a guide to land use planning within the City of San Juan Capistrano and affects many of the issues addressed in the other General Plan elements. The Land Use Element identifies the type and location of future land uses within the City. The specific land uses and their location within the community in turn affect the remaining General Plan elements. For example, the location and type of land uses outlined in the Land Use Element affect the circulation system that is identified in the Circulation Element, and the open space facilities identified in the Land Use Element affect the Conservation and Open Space Element policies. The land uses identified in the Land Use Element also reflect the community's goals for its future form and character.
The Land Use Element addresses future land use within the community. The Element focuses on how vacant land will be allowed to develop, as well as how certain developed land may be redeveloped for other use. The principal goal should be to preserve the character of a small, rural, village-like community with abundant open space. Six major issues are addressed in the goals, policies, and implementation actions of the Land Use Element. These major issues include: (1) balancing land uses within the City to ensure that revenue generation matches service provision responsibilities; (2) controlling and directing future growth within the City so that the community character is preserved; (3) protecting open space areas to protect the public safety and the visual quality of the community; (4) promoting economic development within the community; and (5) enhancing and preserving the character of existing neighborhoods.
18 2000 U.S. Decennial Census; 2010 U.S. Census American Community Survey; and Nielsen Co., 2016
August 2019 34
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) Controlled and Directed Growth
San Juan Capistrano, as well as the surrounding region, has experienced substantial growth over the past 25 years. New development brings change and a changing community character. While recognizing that change is inevitable, the community is still able to plan and guide future development so that it complements the existing community and enhances the existing character and themes found in San Juan Capistrano. Population Distribution and Open Space
Land use density varies depending upon the ability of the specific land to support residential development. Development in the flat lands in the valley floor, if located outside of the floodplain, creates lower risks to residents in comparison to the hillsides, which are subject to landslides and erosion. As a result, higher densities of population could be allocated to those areas posing lower risks. Balance of Land Use
The variety of land uses within San Juan Capistrano affects the important balance between the generation of public revenues and the provision of public facilities and services. Achieving and maintaining a balance of land uses can ensure fiscal stability and also create a desirable community in which people can work, shop, reside, and recreate. The majority of San Juan Capistrano is developed, and limited vacant land is available for future new development. As a result, future growth will occur with the development of the few remaining vacant parcels of land and the redevelopment of currently developed parcels. The Land Use Plan identifies the land uses for these parcels, which will create a land use composition that provides a balance between the generation of public revenues and the cost of providing public facilities and services. Implementation of the Land Use Plan will also assist in creating a balance between the number of jobs and housing units within the City. A balance between jobs and housing allows some people to live and work within the same community. This results in a reduction of traffic, thereby reducing the level of air pollution and improving the quality of life for the community. San Juan Capistrano is located within a housing rich sub-region. The City will implement the Land Use Plan to assure that a balance of land uses occurs, maintaining fiscal stability and an improved job/housing balance.
August 2019 35
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) Land Use Classification System
The Land Use Policy Map (Map 2.1) illustrates the various types and distribution of land uses planned for San Juan Capistrano. The land use classification system includes land use designations. These land use designations identify the types and nature of development allowed in particular locations depicted on the Land Use Policy Map. The residential category includes designations that allow for a range of housing types and densities. The non-residential categories include a variety of designations, such as neighborhood commercial, general commercial, industrial park, light industrial, quasi-industrial, and office/research park to promote a wide range of revenue and employment generating businesses. Other non-residential designations include public/institutional and open space and recreation to provide for public uses and open space. Land Use Designations
All land in the San Juan Capistrano planning area is assigned to one of the land use designations:
Open Space & Recreation Industrial 1.0 General Open Space 4.0 Industrial Park 1.1 Open Space Recreation 4.1 Quasi-Industrial 1.2 Neighborhood Park 4.2 Agri-Business 1.3 Community Park 4.3 Office/Research Park 1.4 Specialty Park Public/ Institutional Designations 1.5 Regional Park 5.0 Public & Institutional 1.6 Natural Open Space 5.1 Existing Public Schools 1.7 Recreation Commercial 5.2 Potential Public Schools 5.3 Assisted Care Facilities Residential 2.0 Very Low Density Special Designations 2.1 Low Density 2.2 Medium Low Density Special Study 2.3 Medium Density 2.4 Medium High Density Specific Plan/Precise Plan 2.5 High Density Commercial 3.0 Neighborhood Commercial 3.1 General Commercial
August 2019 36
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Map 2.6: City of San Juan Capistrano Land Use Map
August 2019 37
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) DEVELOPMENT TRENDS AND FUTURE DEVELOPMENT In the City of San Juan Capistrano, the demand for housing outstrips the available supply, and the recent low interest rates have further fueled a pent up demand. Demand for available housing is extremely high with few existing homes available. Demand for low to medium priced homes continues to be strong. The median value of homes in the City of San Juan Capistrano was estimated at $337,800 according to the 2000 Census. As of December 2018, the median price in San Juan Capistrano was estimated to be over $776,250. This climb in valuation is expected to continue into the foreseeable future.
To address development issues, the Planning and Development Department has engaged in activities that promote the quality of life for the citizens of the City of San Juan Capistrano. The large-scale effort by the City of San Juan Capistrano includes neighborhood and other public facility improvements, rehabilitation of existing housing, and new housing development. The United States Department of Housing and Urban Development (HUD) provides funding through the California Department of Housing and Community Development (HCD) for the City of San Juan Capistrano's Community Program, and the City participates in the Community Development Block Grant (CDBG) program.
Subtle but very measurable changes occur constantly in communities that increase the potential loss that will occur in a major disaster. There are a number of factors that contribute to this increasing loss potential. First, populations continue to increase, putting more people at risk within a defined geographic space. Second, inflation constantly increases the worth of real property and permanent improvements. Third, the amount of property owned per capita increases over time. Table 2.10 identifies current development activities in the city.
Table 2.11: Current Development Activities Area Permit N0. Address Description Status S.F. Under Construction B18-0496 31692 El Camino Real 124 Unit Hotel 92,379 Active B174-1373 29273 Stallion Ridge Church 16,685 Active Church B19-0323 31641 La Novia Ave. 3,875 Active (Tenant Improvements) Ocean Hills Trade Winds 164 SFD Active Harbor View Track Development In Plan Check B19-0413 31872 Del Obispo St. Chick-Fil-A 2,905 Under Review PROTEA B19-0935 31451 Avenida Los Cerritos Under Review 70-Bed Memory Care B18-0682 33122 Valle Rd. CUSD Solar Canopies Under Review B19-0620 Don Juan Villas Track 16802 4 Duplexes Under Review
August 2019 38
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) EVACUATION ROUTES The City of San Juan Capistrano is bisected north/south by Interstate 5, Ortega Highway (state highway 74) leads into the city from the east where it intersects Interstate 5, and Pacific Coast Highway runs along the coast just south of the city’s boundaries. All other thoroughfares are local to city businesses and residents.
Interstate 5 runs north/south and bisects the city roughly in half providing an effective evacuation corridor for a large portion of the city.
State Highway 74 (Ortega Highway) provides an escape route over the Santa Ana Mountains for vehicles evacuating east toward Lake Elsinore and Interstate Highway 15.
Avenida La Pata is the eastern boundary of the city and provides an escape route north to Ortega Highway and south toward San Clemente.
Rancho Viejo Rd. provides a north bound escape route on the east side of Interstate 5 toward Mission Viejo.
Camino Capistrano provides a north bound escape route on the west side of Interstate 5 toward Mission Viejo and a south bound escape route toward San Clemente.
Valle Rd. provides an escape route north to La Novia Ave. where Interstate 5 can be accessed north and south.
La Novia Ave. provides an escape route north to Ortega Highway and south to Interstate 5.
August 2019 39
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Map 2.7: Major Evacuation Corridors
August 2019 40
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) CRITICAL FACILITIES Critical facilities are defined as the following:
Facilities that produce, use, or store highly volatile, flammable, explosive, toxic, and/or water-reactive materials Hospitals, nursing homes, and housing likely to contain occupants who may not be sufficiently mobile to avoid death or injury during a disaster Police stations, fire stations, vehicle and equipment storage facilities, and emergency operations centers that are needed for disaster response activities before, during, and after an event Public and private utility facilities that are vital to maintaining or restoring normal services
The LHMP Team identified 50 critical facilities for incorporation in the hazard vulnerability/risk analysis. These facilities include police stations, fire stations, several City-owned properties, and other facilities that provide important services to the community. Damage to these facilities caused by a hazardous event has the potential to impair response and recovery and may lead to the disruption of services.
This list generally includes critical facilities owned and operated by the City; however, several non-City owned critical facilities, such as fire stations and shelter locations, are listed in Table 2.12.
Table 2.12: San Juan Capistrano Critical Facilities Map # Name Address
1 City Hall 32400 Paseo Adelanto
2 Utilities Yard 32450 Paseo Adelanto
3 Dance Hall\Police Services 32506 Paseo Adelanto
4 Utilities Department Offices 32450 Paseo Adelanto
5 OCFA Fire Station #7 31865 Del Obispo Street
6 SJC City Gym/Boys & Girls Club 25925 Camino Del Avion
7 South Coast Christian Assembly 31501 Avenida Los Cerritos
8 Groundwater Recovery Plant (GWRP) 32470 Paseo Adelanto
9 Public Works Yard 32450 Paseo Adelanto
10 Old Fire Station Complex 31421 La Mantanza Street
11 SJC Community Center 1 Via Positiva
August 2019 41
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Map # Name Address
12 San Juan Capistrano Regional Library 31495 El Camino Real
13 Mariners Church Ocean Hills 32222 Del Obispo Street
14 South Cooks Well 27396 Calle Arroyo
15 JSerra Catholic High School 26351 Junipero Serra Road
16 San Juan Hills High School 29211 Stallion Ridge
17 St. Margaret's Episcopal School 31641 La Novia Avenue
18 Reed Reservoir Zone 2 #1 28422 Via Entrada
19 760 Reservoir South 27271 Calle Delgado
20 Reed Reservoir Zone 2 #1B 28422 Via Entrada
21 Terminal Reservoir #2 27100 Highland Drive
22 Terminal Reservoir #3 26861 Mission Hills Drive
23 High West Side Reservoir #2 31572 Aguacate Road
24 High West Side Reservoir #1 31572 Aguacate Road
25 Cooks Reservoir 25702 Calle Ricardo
26 Zone 3 #2 Reservoir (Lower Hunt Club) 30761 Steeplechase Drive
27 Zone 3 #1 Reservoir (Upper Hunt Club) 30561 Steeplechase Drive
28 Mission Hills Reservoir 21800 Highland Drive
29 CVWD Well #1 32510 Del Zura
30 SJBA Well #2 26372 Paseo Toscana
31 Tirador Well 27122 Paseo Tirador
32 Kinoshita Well 32784 Alipaz Street
33 Well #5A 27802 Calle Arroyo
34 SJBA Well #4 32703 Vivente De Marlita
35 North Open Space Well 30291 Camino Capistrano
36 Bear Brand (Aguacate) Pump Station 31672 Aguacate Road
37 Bear Brand (Peppertree Bend) Pump Station 31546 Peppertree Bend
38 Capistrano Royale Pump Station 26911 Highland Drive
August 2019 42
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Map # Name Address
39 Captain's Hill Pump Station 25702 Windjammer Drive
40 Mission Hills Pump Station 26902 Mission Hills Drive
41 Zone 2 Pump Station 31232 Paseo Crucero
42 Hidden Mountain Pump Station 31632 Via Cervantes
43 Rosenbaum Well #1 29688 Rancho Viejo Road
44 Dance Hall Well 32470 Paseo Adelanto
45 Mission Street Well 26601 Mission Street
46 Strawberry Hill Pump Station 31261 El Horno Street
47 Rosenbaum Lift Station 29688 Rancho Viejo Road
48 Master Meter CM10 ETM 28901 Camino Capistrano
49 Tricities Interconnect Del Obispo @ Stonehill Drive
50 SC-04 Flow Station Ortega Highway & Antonio Parkway
Table 2.13: Types of Critical Facilities Type of Facility Number of Facilities
Government Services 6
Community Services 4
Schools & Churches (shelter locations) 5
Reservoirs 11
Water Wells 11
Boosters, Pumps, and Stations 9
Other 4
August 2019 43 City of San Juan Capistrano Local Hazard Mitigation Plan Map 2.8: City of San Juan Capistrano Critical Facility Locations Number Name Address 1 City Hall 32400 Paseo Adelanto 2 Utilities Yard 32450 Paseo Adelanto 3 Dance Hall\Police Services 32506 Paseo Adelanto 4 Utilities Department Offices 32450 Paseo Adelanto 5 OCFA Fire Station #7 31865 Del Obispo Street 6 SJC City Gym/Boys & Girls Club 25925 Camino Del Avion 7 South Coast Christian Assembly 31501 Avenida Los Cerritos 8 Groundwater Recovery Plant (GWRP) 32470 Paseo Adelanto 9 Public Works Yard 32450 Paseo Adelanto 10 Old Fire Station Complex 31421 La Mantanza Street 11 SJC Community Center 1 Via Positiva 12 San Juan Capistrano Regional Library 31495 El Camino Real 13 Mariners Church Ocean Hills 32222 Del Obispo Street 14 South Cooks Well 27396 Calle Arroyo 15 JSerra Catholic High School 26351 Junipero Serra Road 16 San Juan Hills High School 29211 Stallion Ridge 17 St. Margaret's Episcopal School 31641 La Novia Avenue 18 Reed Reservoir Zone 2 #1 28422 Via Entrada 19 760 Reservoir South 27271 Calle Delgado 20 Reed Reservoir Zone 2 #1B 28422 Via Entrada 21 Terminal Reservoir #2 27100 Highland Drive 22 Terminal Reservoir #3 26861 Mission Hills Drive 23 High West Side Reservoir #2 31572 Aguacate Road 24 High West Side Reservoir #1 31572 Aguacate Road 25 Cooks Reservoir 25702 Calle Ricardo 26 Zone 3 #2 Reservoir (Lower Hunt Club) 30761 Steeplechase Drive 27 Zone 3 #1 Reservoir (Upper Hunt Club) 30561 Steeplechase Drive 28 Mission Hills Reservoir 21800 Highland Drive 29 CVWD Well #1 32510 Del Zura 30 SJBA Well #2 26372 Paseo Toscana 31 Tirador Well 27122 Paseo Tirador 32 Kinoshita Well 32784 Alipaz Street 33 Well #5A 27802 Calle Arroyo 34 SJBA Well #4 32703 Vivente De Marlita 35 North Open Space Well 30291 Camino Capistrano 36 Bear Brand (Aguacate) Pump Station 31672 Aguacate Road 37 Bear Brand (Peppertree Bend) Pump Station 31546 Peppertree Bend 38 Capistrano Royale Pump Station 26911 Highland Drive 39 Captain's Hill Pump Station 25702 Windjammer Drive 40 Mission Hills Pump Station 26902 Mission Hills Drive 41 Zone 2 Pump Station 31232 Paseo Crucero 42 Hidden Mountain Pump Station 31632 Via Cervantes 43 Rosenbaum Well #1 29688 Rancho Viejo Road 44 Dance Hall Well 32470 Paseo Adelanto 45 Mission Street Well 26601 Mission Street 46 Strawberry Hill Pump Station 31261 El Horno Street 47 Rosenbaum Lift Station 29688 Rancho Viejo Road 48 Master Meter CM10 ETM 28901 Camino Capistrano 49 Tricities Interconnect Del Obispo @ Stonehill Drive 50 SC-04 Flow Station Ortega Hwy & Antonio Pkwy
August 2019 44
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
The LHMP Team identified replacement and content values for a majority of the facilities based on the City’s insured values; these represent the total loss value for each facility. If a facility is completely destroyed in a hazardous event, the replacement and content values indicate the cost to replace the facility. Depending on the year the facility was built, the cost to repair a damaged facility may be more than the replacement value. While replacement and content values are used throughout this plan to estimate potential losses, it is noted that the actual cost to recover from a hazard will depend on the type and magnitude of the event.
Table 2.14: San Juan Capistrano Critical Facilities Costs Replacement Contents Potential Map # Facility Value Value Loss 1 City Hall $6,000,000 $3,000,000 $9,000,000 2 Utilities Yard $859,760 $667,666 $1,527,426 3 Dance Hall\Police Services $675,137 $37,859 $712,996 4 Utilities Department Offices $505,150 $867,709 $1,372,859 5 OCFA Fire Station #7 * * * 6 SJC City Gym/Boys & Girls Club $4,374,080 $10,000 $4,384,080 7 South Coast Christian Assembly * * * 8 Groundwater Recovery Plant (GWRP) $27,042,929 $0 $27,042,929 9 Public Works Yard $525,574 $822,313 $1,347,887 10 Old Fire Station Complex $3,208,197 $34,364 $3,242,561 11 SJC Community Center $7,367,194 $440,523 $7,807,717 12 San Juan Capistrano Regional Library $7,800,083 $50,000 $7,850,083 13 Mariners Church Ocean Hills * * * 14 South Cooks Well na na na 15 JSerra Catholic High School * * * 16 San Juan Hills High School * * * 17 St. Margaret's Episcopal School * * * 18 Reed Reservoir Zone 2 #1 $15,289 $2,827,748 $2,843,037 19 760 Reservoir South $7,184,567 $0 $7,184,567 20 Reed Reservoir Zone 2 #1B $15,289 $1,026,062 $1,041,351 21 Terminal Reservoir #2 na na na 22 Terminal Reservoir #3 $21,115,227 $0 $21,115,227 23 High West Side Reservoir #2 $95,560 $388,244 $483,804 24 High West Side Reservoir #1 $95,560 $323,611 $419,171 25 Cooks Reservoir $57,338 $0 $57,338 26 Zone 3 #2 Reservoir (Lower Hunt Club) $420,454 $1,422,378 $1,842,832 27 Zone 3 #1 Reservoir (Upper Hunt Club) $0 $776,044 $776,044 28 Mission Hills Reservoir na na na 29 CVWD Well #1 na na na 30 SJBA Well #2 na na na 31 Tirador Well na na na
August 2019 45
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Replacement Contents Potential Map # Facility Value Value Loss 32 Kinoshita Well na na na 33 Well #5A na na na 34 SJBA Well #4 na na na 35 North Open Space Well $0 $1,292,665 $1,292,665 36 Bear Brand (Aguacate) Pump Station $477,789 $1,292,843 $1,770,632 37 Bear Brand (Peppertree Bend) Pump Station $1,903,917 $0 $1,903,917 38 Capistrano Royale Pump Station $477,789 $1,292,843 $1,770,632 39 Captain's Hill Pump Station $477,789 $1,292,843 $1,770,632 40 Mission Hills Pump Station $477,789 $1,918,841 $2,396,630 41 Zone 2 Pump Station $783,573 $1,282,600 $2,066,173 42 Hidden Mountain Pump Station $477,789 $646,511 $1,124,300 43 Rosenbaum Well #1 $0 $1,292,665 $1,292,665 44 Dance Hall Well na na na 45 Mission Street Well na na na 46 Strawberry Hill Pump Station na na na 47 Rosenbaum Lift Station $0 $132,823 $132,823 48 Master Meter CM10 ETM na na na 49 Tricities Interconnect na na na 50 SC-04 Flow Station $152,893 $996,160 $1,149,053 Total Potential Losses $92,586,716 $24,135,315 $116,722,031 Replacement value information based on City insured values for each facility. * - Not City Owned na - No Data Available Facilities of Concern
Facilities of concern include public and private education facilities with student populations and in some circumstances could serve as shelter locations.
Table 2.15: School Facilities in San Juan Capistrano Public Schools Location San Juan Hills High School (Shelter) 29211 Stallion Ridge Marco Forster Middle School 25601 Camino Del Avion Ambuehl Elementary School 28001 San Juan Creek Rd Del Obispo Elementary School 25591 Camino Del Avion Kinoshita Elementary School 2 Via Positiva San Juan Elementary School 31642 El Camino Real Serra High School 31422 Camino Capistrano Bridges Adult Transition & Capo Virtual Academy 33122 Valle Rd.
August 2019 46
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Private School Facilities Location Capistrano Valley Christian School 32032 Del Obispo Capistrano Valley Head Start 31485 El Camino Real Marbella Montessori Pre-School 31113 Rancho Viejo Road Community Presbyterian Pre-School 32202 Del Obispo Mission Basilica School 31641 El Camino Real Saddleback Valley Christian School 26333 Oso Road San Juan Montessori Pre-School 32143 Alipaz Stoneybrooke Christian School 26300 Via Escolar Evelyn Lobo Villegas Head Start 32204 Del Obispo St. Margaret’s Episcopal School (Shelter) 31641 La Novia Ave. JSerra Catholic High School (Shelter) 26351 Junipero Serra Road Kindergarten Readiness- 31421 La Matanza Mon-Thurs 8:30-12:30 (Old Fire Station Complex) Coastal Mountain Youth 38171 Paseo Cervesa South Coast Christian Assembly 31501 Avenida Los Cerritos
Facilities of Interest
Facilities of interest are Non City-owned properties that may do any of the following:
Contain sensitive populations Provide key infrastructure Facilitate delivery of utility services Contain large numbers and density of employees, residents, or students Contain buildings with unreinforced masonry construction or pre-1975 Concrete Tilt-Up Construction Historical and cultural landmarks
Tables 2.16 through 2.24 identify Facilities of Interest.
Table 2.16: Medical Facilities Facility Location
Urgent Care of San Juan Capistrano 32112 Camino Capistrano Urgent Care 32312 Camino Capistrano Kaiser Permanente Medical Care 30400 Camino Capistrano Partners in Health 32241 Camino Capistrano, #105 Camino Health Center 30300 Camino Capistrano Memorial Care Medical Group 30300 Rancho Viejo Rd DaVita Dialysis 31736 Rancho Viejo Road, Suite B-D
August 2019 47
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Table 2.17: Transportation–Interstate & City Arterials Facility Location
Interstate - 5 Runs north/south through entire city.
Camino Capistrano Runs north/south through entire city - parallel to & on west side of I-5.
Begins at Ortega Hwy south of I-5 and runs southwest through City’s south boundary Del Obispo and ends at PCH in Dana Point. Begins at Calle Arroyo on east side of I-5 and runs parallel to I-5 to City’s north Rancho Viejo Rd. boundary, where it becomes Marguerite Parkway.
San Juan Creek Rd Begins at Camino Capistrano/I-5 and runs north/east to Camino Chico. Begins at Camino Capistrano and runs north/east to City N/E boundary (City street Ortega Hwy (74) west of I-5, State highway east of I-5).
Table 2.18: Transportation - Trains Facility Location
Los Rios & Verdugo Streets (Pedestrian crossing only. Vehicular crossing possible in Train Depot emergency). Railroad tracks Runs north/south through entire city
Railroad crossing Oso Road at Camino Capistrano
Railroad crossing La Zanja at Camino Capistrano
Railroad crossing Del Obispo at Los Rios
Railroad crossing Aeropuerto at Camino Capistrano
Table 2.19: Transportation – Bridges Facility Location
City Vehicular Bridge #55C-2 Trabuco Creek Channel (Ranch Viejo Road)
City Vehicular Bridge #55C-34 San Juan Creek Channel (Camino Capistrano)
City Vehicular Bridge #55C-62 San Juan Creek Channel (La Novia Avenue)
City Vehicular Bridge #55C-266 Trabuco Creek Channel (Camino Capistrano)
City Vehicular Bridge #55C-396 Trabuco Creek Channel (Del Obispo Street)
City Vehicular Bridge #55C-505 Horno Creek Channel (Rancho Viejo Road)
City Vehicular Bridge #55C-608 Stonehill Drive O.H. (Lossan Rail Corridor)
City Recreational Bridge Vereda Bikeway (crossing at Trabuco Creek at San Juan Creek)
August 2019 48
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Facility Location
City Recreational Bridge Trabuco Creek Trail (crossing at Trabuco Creek at Rancho Viejo Road)
Freeway Bridge I-5 & Camino Las Ramblas
Freeway Bridge I-5 & Serra On Ramp at Stonehill
Freeway Bridge I-5 & San Juan Creek Road
Freeway Bridge I-5 & San Juan Creek
Freeway Bridge I-5 & Horno Creek South
Freeway Bridge I-5 & Ortega Hwy – overbridge
Freeway Bridge I-5 & Horno Creek North
Freeway Bridge I-5 & El Horno Street
Freeway Bridge I-5 & Junipero Serra Road
Freeway Bridge I-5 & Trabuco Creek
Table 2.20: Utilities Facility Location
At Ortega Hwy & San Juan Creek bridge crossing, there are marker signs Southern California (800.548.6841). Also, various pipelines throughout city. The main Gas Company transmission line parallels the I-5 through town. See OCFA Hazmat Area Plan for more detail.
SDG&E Substation 31050 Camino Capistrano
AT&T Central Office (all City 25672 Camino Del Avion lines)
The 16” underground pipeline runs north/south just east of the City in the Kinder-Morgan Energy unincorporated part of Orange County. A portion of the pipeline intersects (Petroleum Lines: product is approximately 2,100 feet (.4 miles) at a northeastern boundary from about refined petroleum) Ortega Hwy to San Juan Creek Road. The main line runs from the Long Beach Harbor area to the San Diego Harbor area.
August 2019 49
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Table 2.21: High Occupancy Structures (Approximate number of employees, residents, and/or students) Facility Location
Mission San Juan Capistrano (170) 26801 Ortega Hwy.
Fluidmaster (215) 30800 Rancho Viejo Rd.
CUSD Offices (250) 33122 Valle Road
Nichols Institute Diagnostics (1200) 33061 Calle Aviador
Costco (270) 33961 Doheny Park Rd.
Emeritus at San Juan Cap.(154) 31741 Rancho Viejo Rd. Residents: 149 J Serra Catholic High School (150) 26351 Junipero Serra Rd Students: 1050 St. Margaret’s Episcopal School (204) 31641 La Novia Students: 1222 Silverado Senior Living: SJC (100) 30311 Camino Capistrano Residents: 91 Color Spot Nurseries (180) 31101 Ortega Highway
Marbella Country Club (106) 30800 Golf club Drive
Table 2.22: High Risk Construction – Unreinforced Masonry Building Facility Location
Mission San Juan Capistrano 26801 Ortega Hwy. Mission Promenade 26832 Ortega Hwy (Property Manager for 3C-03 to 3C-10) Business 26860 Ortega Hwy
Business 26850 Ortega Hwy
Business 31760 Camino Capistrano
Business 31770 Camino Capistrano
Business 26701 Verdugo St.
Business 31733 Los Rios
Business 31815 Camino Capistrano
Business 31831 Camino Capistrano
Business 31891 Camino Capistrano
August 2019 50
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Facility Location
Business 31892 Camino Capistrano
Business 31806 El Camino Real
Business 31421 La Matanza St.
Business 27762 Ortega Hwy
Business 31422 Camino Cap
Table 2.23: High Risk Construction – Pre-1975 Concrete Tilt-Up Construction Facility Location
Retail 26131 Ave. Aeropuerto
Warehouse 26181 Ave. Aeropuerto
Warehouse 33046 Calle Aviador
Warehouse 33047 Calle Aviador
Warehouse 33049 Calle Aviador
Warehouse 33051 Calle Aviador
Warehouse 33061 Calle Aviador
Vacant 33062 Calle Aviador
Warehouse 33092 Calle Aviador
Wholesale Store 32981 Calle Perfecto
Warehouse 32992 Calle Perfecto
Light Industrial 33001 Calle Perfecto
Light Industrial 33012 Calle Perfecto
Warehouse 33021-23 Calle Perfecto
Warehouse 33041 Calle Perfecto
Light Industrial 33081 Calle Perfecto
Warehouse 33091 Calle Perfecto
August 2019 51
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Table 2.24: Historical and Cultural Landmarks Property Name Location
26801 Ortega Highway & 31522 Camino Mission San Juan Capistrano Capistrano Rios Adobe 31781 Los Rios Street Montañez Adobe 31745 Los Rios Street Silvas Adobe 31861 Los Rios Street Mission Kiln 31401 El Horno Street Miguel Parra Adobe 27762 Ortega Highway Pablo Pryor Adobe/Hide House 33751 Camino Capistrano Blas Aguilar Adobe (Casa de Esperanza) 31806 El Camino Real Manuel Garcia Adobe 31861 Camino Capistrano Burruel Adobe Ruins El Camino Real and Forster St. Domingo Yorba Adobe 31871 Camino Capistrano Juan Avila Adobe 31831 Camino Capistrano El Adobe Restaurant/Juzgado/Jose Antonio Yorba Adobe 31891 Camino Capistrano Santa Fe Depot 26701 Verdugo Street Egan Residence 31892 Camino Capistrano Buddy Forster Residence 31721 Los Rios Street Frank A. Forster Mansion 27182 Ortega Highway Garcia/Pryor Residence - O'Neill Museum 31831 Los Rios Street Hankey/Rowse Cottage 30981 Via Cristal C. Russell Cook Barn: no longer on premises, burned down 32222 Del Obispo in 2011 Hot Springs Dance Hall 32506 Paseo Adelanto Joel Congdon Residence 32701 Alipaz Street R. B. Cook House/Ocean Hills Community Church 32272 Del Obispo Street Errecarte House 30882 Via Errecarte Harrison Farmhouse 27762 Ortega Highway English/Hardy House 26652 Ramos Street Old San Juan Capistrano Fire Station Complex La Matanza and El Horno Community Christian Church 31612 El Camino Real Eyraud-Chabre-Lohrbach House 31382 El Camino Real Stroschein House 31682 El Camino Real
August 2019 52
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Property Name Location
Esslinger Building 31866 Camino Capistrano 26822, 26832, 26842 Ortega Highway El Peon Complex/Ferris-Kelly Buildings 31752, 31754, 31762 Camino Capistrano Durnford/Marco Forster House 31319 Andres Pico Road Ross Ranch House 31491 La Calera Street Walter Congdon House (rear); C.C. McCary House (front) 31501 La Matanza Street Albert Pryor Jr. House 31321 Andres Pico Road Bill Rosenbaum House 31440 El Camino Real Hugo Forster House #2 31341 Andres Pico Road Arley Leck House 31865 Los Rios Street Roger Y. Williams/Swanner House Complex 29991 Camino Capistrano Mission Refuse Area El Camino Real & El Horno Mission Cemetery Ortega Highway River Street In the Los Rios Historic District Capistrano Union High School Site 31422 Camino Capistrano Los Rios Historic District All along Los Rios St. Little Hollywood 31362 & 31342 Ramos St., 26604 Mission Street
Table 2.25: Historic Streets Property Name Location
Los Rios Street From Del Obispo Street to Mission Street
El Camino Real From La Zanja to Forster Street
Camino Capistrano From Ortega Highway to Del Obispo Street
Spring Street From El Camino Real to east terminus at I-5
Hot Springs Road Ortega Hwy.
August 2019 53
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Page Intentionally Left Blank
August 2019 54
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) CHAPTER 3: HAZARD ASSESSMENT For the purposes of the City of San Juan Capistrano, a hazard is any event that poses an uncommon threat to lives, property, or the environment in the City. The hazard assessment conducted in conjunction with the revision of the City of San Juan Capistrano’s Local Hazard Mitigation Plan update sought to build on previous local hazard assessments while also considering hazard lists available from the Federal Emergency Management Agency and the National Fire Protection Association. From these lists, a primary hazard list was developed for San Juan Capistrano, and hazard profiles were prepared to assess the probability and impact of each hazard. HAZARD IDENTIFICATION The LHMP Team discussed a comprehensive list of natural hazards at the first team meeting. This discussion resulted in the identification of natural and man-made hazards that pose a potential risk to the City of San Juan Capistrano.
Table 3.1 shows which hazards were identified in the 2015 County of Orange and the Orange County Fire Authority Local Hazard Mitigation Plan, and which hazards were identified for inclusion in this 2019 revision of the San Juan Capistrano LHMP. This table also summarizes the LHMP Team’s discussion for each of the hazards. Hazards that have been excluded from further consideration are shaded gray. This table is consistent with the hazards identified as part of FEMA’s hazard mitigation planning guidance.
Table 3.1: City of San Juan Capistrano Hazard Identification 2019 Identified in Included in 2015 Orange the City of List of Hazards Discussion Summary County SJC LHMP LHMP 2019 Update There has been no significant damage from Agricultural Pests No No agricultural pests. Avalanche No No Not applicable. Coastal Erosion/Bluff No No Not applicable due to the distance from the coast. Failure Coastal Storm No No Not applicable due to the distance from the coast. There are no dams in the city; however, there could be inundation caused by a dam failure in Dam Failure Yes Yes surrounding areas. The LHMP Team decided to combine Dam Failure with Flooding.
Epidemic and Vector Potential epidemics and vector issues are of Yes Yes Borne Disease concern.
Drought Yes Yes Drought is an area of concern. San Juan Capistrano is located in an area Seismic Hazards Yes Yes susceptible to earthquake ground shaking and liquefaction.
August 2019 55
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Identified in Included in 2015 Orange the City of List of Hazards Discussion Summary County SJC LHMP LHMP 2019 Update
Expansive Soils No No Not applicable.
Extreme heat is a concern. The LHMP Team Extreme Heat Yes Yes decided to combine Extreme Heat with Severe Weather.
Flooding in the City occurs as a result of surface Flood Yes Yes water runoff from the mountains and heavy rain.
Hailstorm No No Not applicable.
There are a number of properties in the City containing hazardous materials. The LHMP Team decided to include a discussion of this hazard Hazardous Material given the amount of hazardous materials located No Yes Spills within and transported through the City. The LHMP Team decided to title the hazard profile “Transportation and Hazardous Materials Incidents”.
Hurricane No No Not applicable.
San Juan Capistrano has no historical occurrences Land Subsidence No No of land subsidence. Landslide and Debris Yes Yes Debris flow discussed in Flood Hazard Profile Flow Human Caused No Yes Radiological/Nuclear Hazard Profile Hazards A discussion is provided on terrorism due to Terrorism No Yes terrorist incidents around the world The LHMP Team decided to combine severe Severe Storm No Yes winter storm, extreme heat, and high wind into a hazard profile titled “Severe Weather” Tornado No No Not applicable.
Tsunami Yes No Not applicable.
Volcano No No Not applicable.
Wildfires Yes Yes The city is prone to wildland and urban fires The city is prone to severe winds that commonly High Wind (Santa Ana Yes Yes cause damage in the area combined with Severe Winds) Windstorm Weather. Sea Level Rise No No Not applicable.
Climate Change No Yes Climate change is addressed throughout the Plan.
August 2019 56
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) Selected Hazards
As a result of discussions with the LHMP Team and City Staff, the following hazards were selected for inclusion in the Plan. These hazards are presented in alphabetical order and are not listed in order of priority or importance.
Drought Epidemic and Vector Borne Disease Flood Landslide Radiological/Nuclear Hazard Seismic Hazard Severe Weather Terrorism Transportation and Hazardous Materials Incident Wildfire
August 2019 57
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) CLIMATE CHANGE CONSIDERATIONS According to the U.S. Environmental Protection Agency (EPA), Earth's average temperature has risen by 1.4°F over the past century and is projected to rise another 2°F to 11.5°F over the next hundred years. Small changes in the average temperature of the planet can result in large and potentially dangerous shifts in climate and weather.19
With increases in temperature, Earth’s climate is changing. Snow and rainfall patterns are shifting, and more extreme climate events like heavy rainstorms and record high temperatures are already occurring. Scientists are highly confident that many of these observed changes can be linked to the climbing levels of carbon dioxide and other greenhouse gases in our atmosphere, which are caused by human activities.20
Figure 3.1: Changes to Earth’s Atmospheric CO221
Economic Impact
According to a June 29, 2017 article in Sciencemag.org, economists give the problems caused by climate change an appropriately dismal name: the damage function. To project just how much damage each U.S. county will incur by century's end, researchers ran 29,000 simulations of the U.S. economy, with results informed by weather-driven damages they detected in six domains–agriculture, crime, health, energy demand, labor, and coastal communities between 1981 and 2010. Heat, for example, may increase crime or cause corn yields to fall, but it also could lower fatalities driven by exposure to the cold. The resulting prediction, though quite fallible in its inability to predict how humans will adapt to warming, foresees a country where, if fossil fuels continue to pour carbon into the atmosphere, the United States will divide further into a country of haves and have-nots. Not surprisingly, Atlantic coastal communities are projected to take a toll from rising seas and strengthening hurricanes, but also much of the South and Midwest will be hurt by a decline in farming caused by rising temperatures, along with increasing energy demands to keep up with the heat. Meanwhile, states in the north and northwest could
19 United Sates Environmental Protection Agency, https://www.epa.gov/climate-research 20 County of Orange & Orange County Fire Authority Local Hazard Mitigation Plan November 2015 21 NASA, Global Climate Change, Vital Signs of the Planet, https://climate.nasa.gov/climate_resources/24/graphic-the-relentless-rise-of-carbon-dioxide/
August 2019 58
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) see their fortunes mildly boosted by warming, with farming yields rising thanks to shorter winters and less need to ward off harsh cold in homes. That’s not enough to counteract an overall negative trend for the country, which, if the planet warmed by 6°C from preindustrial levels, could suffer damage worth 6% of its gross domestic product, the team reports today in Science.
The results, shown in Map 3.1, could guide states and the federal government toward the communities most in need of help adapting to the changed climate should lawmakers choose to act.22
Map 3.1: Total Economic Damage to the US Gross Domestic Product by County
Red means total economic damage and blue is total economic benefit; projections are for 2080-2100. Local Impact
Climate change is expected to exacerbate existing hazards in the City of San Juan Capistrano. As such, the LHMP Team determined that it would be best to discuss climate change considerations throughout all applicable hazard profiles. To address potential climate change impacts, the City has identified climate change considerations within each hazard profile. This discussion is intended to supplement, but not replace, the “Probability of Future Occurrence” discussion.
22 https://www.sciencemag.org/news/2017/06/here-s-how-much-climate-change-going-cost-your-county
August 2019 59
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) HAZARD PROFILES Drought
General Background
Drought is a significant decrease in water supply relative to what is typical in a given location. It is a normal phase in the climate cycle of most regions, originating from a deficiency of precipitation over an extended period of time, usually a season or more. Most of California’s precipitation comes from storms moving across the Pacific Ocean. The path followed by the storms is determined by the position of an atmospheric high pressure belt that normally shifts southward during the winter, allowing low pressure systems to move into the State. On average, 75 percent of California’s annual precipitation occurs between November and March, with 50 percent occurring between December and February. A persistent Pacific high pressure zone over California in mid-winter signals a tendency for a dry water year.
A typical water year produces about 100 inches of rainfall over the North Coast, 50 inches of precipitation (combination of rain and snow) over the Northern Sierra, 18 inches in the Sacramento area, and 13 inches to 23 inches in the planning area. In extremely dry years, these annual totals can fall to as little as one half, or even one third, of these amounts.
Determination of when drought begins is based on impacts on water users and assessments of available water supply, including water stored in reservoirs or groundwater basins. Different water agencies have different criteria for defining drought. Some issue drought watch or drought warning announcements. The California water code does not include a statutory definition of drought; however, references to drought in state code generally relate to issues of water shortage (California Code of Regulations (CCR) 2017). Definitions
No simple, precise definition of drought exists. In general, a drought is an extreme event characterized by a prolonged period of abnormally low levels of precipitation that has adverse impacts on vegetation, animals, and people. A drought is a temporary phenomenon and as such, it is distinct from aridity, which is a climatic feature of a particular region. Droughts occur periodically in every climatic zone, although some areas are more drought-prone than others.
August 2019 60
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
The National Oceanic and Atmospheric Administration (NOAA) National Centers for Environmental Information defines four types of drought:
Drought - The cumulative impacts of several dry years on water users. It can include deficiencies in surface and subsurface water supplies and generally impacts health, wellbeing, and quality of life.
Meteorological Drought - Precipitation’s departure from normal over some period of time. Meteorological measurements are the first indicators of drought and are usually region-specific.
Agricultural Drought - Inadequate soil moisture for a particular crop at a particular time.
Hydrological Drought - Deficiencies in surface and subsurface water supplies. It is measured as stream flow and as lake, reservoir, and groundwater levels.
Socioeconomic Drought - Drought impacts on health, wellbeing, and quality of life. Drought Hazard Profile Community Drought Issues San Juan Capistrano Utilities Department’s staff provide for domestic water service, recycled water service, wastewater collection service, and stormwater collection throughout the City. Droughts have social, economic, and environmental implications. The following is a short summary of some of the impacts that typically occur during a drought:23 Water Supply and Quality Drought negatively impacts both the quantity and quality of water supplies. While a reduction in water supply is generally a temporary phenomenon, it can be permanent in some instances. Groundwater overdraft, for example, can cause land to sink, resulting in a permanent loss of groundwater storage. Drought can also compromise water quality, such as by concentrating salts and other contaminants, reducing dissolved oxygen levels, and increasing water temperatures. Water quality problems can exacerbate water supply problems.
Wildfire Dry vegetation combined with high temperatures and low humidity often increases the frequency and intensity of fires. The wildfire season may start earlier in the spring and extend later into the fall. Energy Drought can strain the energy system. The generation of hydroelectricity at California dams may drop dramatically from average levels because it varies directly with streamflow. As the source of electricity production shifts to the more expensive fossil fuel (e.g., natural gas),
23 californiadrought.org/drought/background/ Pacific Institute, California Drought, Impacts and Solutions
August 2019 61
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
electricity prices will likely increase. Additionally, high temperatures associated with drought may increase energy demand for cooling and air-conditioning systems. Agriculture Some farmers and water districts with “junior” water rights have seen water allocations from state and federal irrigation projects severely cut. Some growers with “senior” water rights have seen only modest shortages, if any. Farmers facing a water shortage may seek temporary water transfers from other users, increase groundwater pumping, change the types of crops they grow, deficit irrigate, or leave some lands fallow. Rural Communities Rural communities are often dependent on a single water source, usually groundwater. As groundwater levels drop, community and individual wells may go dry. Declining water supplies and ongoing water quality problems force communities to switch to bottled water, dig deeper wells, and truck in water to refill holding tanks. These actions can impose local economic hardships on those living in rural areas, many of whom are among the state’s most disadvantaged communities. Urban Areas Urban water utilities have rolled out a wide range of voluntary and mandatory water conservation programs. These include educational programs, incentives to purchase more water-efficient appliances and plant water-efficient gardens, and restrictions on discretionary water uses, such as watering lawns. As a result, statewide urban water use has declined by nearly 25% from 2013 levels. Revenue Sources For most water utilities, fixed costs (i.e., debt service on past water system investments) are relatively high and variable costs (i.e., energy and chemical costs) are relatively low. Reducing water use cuts variable costs but has no impact on fixed costs (at least in the short term). As water use declines, revenue from the sale of water also declines and may not be sufficient to recover the fixed costs. In response, water utilities may enact drought surcharges or draw from reserves. While surcharges increase the water rate (i.e., the price per gallon), those using less water may actually see their bills go down. Furthermore, conservation lessens the impact of the drought on water bills by avoiding the purchase of more expensive water supplies. Location and Extent of Drought
Drought affects the potable water supply in the City of San Juan Capistrano in two ways. First, localized drought reduces the amount of water that percolates into the Orange County Groundwater Basin while also increasing water demand for local landscaping needs. Second, drought conditions in the southwest U.S. result in a reduced snowpack in the Colorado Rockies and the Sierra Nevada, which in turn, reduces the amount of surface water available for import into the City.
August 2019 62
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
During the recent drought, much of the state, including the City of San Juan Capistrano, was in a state of “exceptional drought.” “Exceptional drought” is the most severe of five drought distinctions identified by the United States Drought Monitor. Past Occurrences of Drought
Droughts are a recurring feature of California’s climate. In the last century, the most significant statewide droughts occurred in 1929-1934, 1976-1977, 1987-1992, and 2012-2016. A less severe drought occurred in 2007-2009. The 2012-2016 droughts were one of extreme proportions, with record- high temperatures and record-low levels of snowpack and precipitation.24
On January 17, 2014, with California facing water shortfalls in the driest year in recorded state history, Governor Edmund G. Brown Jr. proclaimed a State of Emergency and directed state officials to take all necessary actions to prepare for these drought conditions. In the State of Emergency declaration, Governor Brown directed state officials to assist farmers and communities that were economically impacted by dry conditions and to ensure the state can respond if Californians face drinking water shortages. The Governor also directed state agencies to use less water and hire more firefighters and initiated a greatly expanded water conservation public awareness campaign.25
On April 7, 2017, California Governor Edmund G. Brown Jr. ended the drought State of Emergency in most of California, while maintaining water reporting requirements and prohibitions on wasteful practices, such as watering during or right after rainfall. Executive Order B-40-17 lifted the drought emergency in all California counties except Fresno, Kings, Tulare, and Tuolumne, where emergency drinking water projects would continue to help address diminished groundwater supplies. This order also rescinds two emergency proclamations from January and April 2014 and four drought-related executive orders issued in 2014 and 2015.
Table 3.2: Identifies the historical droughts that have occurred in California from 1855 to the present. Figure 3.3: Illustrates the severity of the drought conditions on July 19, 2016. Figure 3.4: Illustrates the severity of the current drought conditions as for January 29, 2019.
Table 3.2: Historic Droughts in California26 27 Date Area Affected Notes
Multiyear: 1827-1929, 1843-1944, 1856-1957, 1863-1964 Statewide 1827-1916 (particularly extreme), 1887-1988, 1897-1900, 1912-1913.
Statewide except central Simultaneously affected areas, 1919-1920. Most extreme in 1917-1921 Sierra Nevada and north north. coast
24 http://www.californiadrought.org/drought/background/ 25 www.caloes.ca.gov/ICESite/Pages/Drought.aspx 26 USGS.1990.http://geochange.er.usgs.gov/sw/impacts/hydrology/state_fd/cawater1.html; 27 Cook et al. 2009 - http://www.ldeo.columbia.edu/res/div/ocp/pub/cook/2009_Cook_IPCC_paleo-drought.pdf; CA Department of Water Resources. 2010.
August 2019 63
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Statewide except central Simultaneously in effect for entire state only during 1924, and 1922-1926 Sierra Nevada was particularly severe?
Simultaneously in effect for entire the state, 1929-1934. Longest, 1928-1937 Statewide most severe in state's history. Simultaneously in effect for entire state, 1947-1949. Most 1943-1951 Statewide extreme in south. 1959-1962 Statewide Most extreme in Sierra Nevada and central coast.
Statewide, with the Driest 2 years in state's history. Most severe in northern two- 1976-1977 exception of southwestern thirds of state. deserts Moderate, continuing through 1989. Most extreme in northern 1987-1992 Statewide Sierra Nevada. 2000-2002 Statewide Most severe in southern California.
12th driest three-year period on record at the time. Most severe in 2007-2009 Statewide western San Joaquin Valley.
2012-2017 Statewide Most severe California drought on record.
Map 3.2: Drought Severity July 19, 201628
28 https://droughtmonitor.unl.edu/data/pdf/current/current_ca
August 2019 64
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Map 3.3: Drought Severity January 29, 2019
Probability of Future Occurrence
The historical prevalence of severe droughts in California, as well as the severe drought conditions the City and the state are currently facing, indicates that there is a high probability of future occurrence. Climate Change Considerations
There is a close link between climate change and increased drought frequency and severity. Although precise localized impacts of climate change on water resources remain less certain, even in the absence of changes in precipitation patterns, higher temperatures resulting from increased greenhouse gas concentrations are expected to lead to higher evaporation rates, reductions in stream flow, and more frequent droughts. Based on the current data and modeling, it is anticipated that future drought conditions will become more intense and reduce the City’s adaptive capacity. Summary Vulnerability/Risk Assessment
Large metropolitan areas have reasonably secure water supplies but require continued conservation efforts and some new supply investments. In addition to impact on water supplies, drought conditions contribute to extreme wildland fire hazard due to high temperatures, dry conditions, and increased tree mortality in California’s forests.29 For water utility managers, key issues appear to be cost (in
29 Public Policy Institute of California, “What if California’s Drought Continues”, (Accessed February 11, 2019)
August 2019 65
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) particular, avoiding the most expensive solutions until necessary) and the pace of regulatory approvals for new projects. Recent legislation providing exemptions to the California Environmental Quality Act (CEQA) for recycled water project standards will help in this regard. 30 The state’s emergency drought funding program has also aimed to speed up the disbursement of state bond funds to support new water projects.
30 H. McCann and C. Chappelle, “Drought Bills: Small Changes, High Impact” (PPIC blog, June 30, 2015).
August 2019 66
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) Seismic Hazards General Background An earthquake is the vibration of the earth’s surface following the release of energy in the earth’s crust. This energy can be generated by a sudden dislocation of the crust or by a volcanic eruption. Most destructive quakes are caused by dislocations of the crust. The crust may first bend and then, when the stress exceeds the strength of the rocks, break and snap into a new position. In the process of breaking, vibrations called “seismic waves” are generated. These waves travel outward from the source of the earthquake at varying speeds. Geologists have found that earthquakes tend to reoccur along faults, which are zones of weakness in the earth’s crust. Even if a fault zone has recently experienced an earthquake, there is no guarantee that all the stress has been relieved. Another earthquake could still occur. In fact, relieving stress along one part of a fault may increase it in another part of the fault.
California is seismically active because of movement of the North American Plate, east of the San Andreas Fault, and the Pacific Plate to the west, which includes the state’s coastal communities. Movement of the tectonic plates against one another creates stress, which is released as energy that moves through the earth as seismic waves.
Active faults have experienced displacement in historical time; however, inactive faults, where no such displacements have been recorded, also have the potential to reactivate or experience displacement along a branch sometime in the future. An example of a fault zone that has been reactivated is the Foothills Fault Zone. The zone was considered inactive until evidence of an earthquake (approximately 1.6 million years ago) was found near Spenceville, California. Then, in 1975, an earthquake occurred on another branch of the zone near Oroville, California (now known as the Cleveland Hills Fault). The State Division of Mines and Geology indicates that increased earthquake activity throughout California may cause tectonic movement along currently inactive fault systems. Definitions
Earthquake - The shaking of the ground caused by an abrupt shift of rock along a fracture in the earth or a contact zone between tectonic plates.
Epicenter - The point on the earth’s surface directly above the hypocenter of an earthquake. The location of an earthquake is commonly described by the geographic position of its epicenter and by its focal depth.
Fault - A fracture in the earth’s crust along which two blocks of the crust have slipped with respect to each other.
August 2019 67
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Hypocenter - The region underground where an earthquake’s energy originates.
Liquefaction - Loosely packed, water-logged sediments losing their strength in response to strong shaking, causing major damage during earthquakes. Earthquake Classifications Earthquakes are typically classified in one of two ways: by the amount of energy released, measured as magnitude; or by the impact on people and structures, measured as intensity. Magnitude An earthquake’s magnitude is a measure of the energy released at the source of the earthquake. It is commonly expressed by ratings on either of two scales (USGS, 2017a): The Richter scale measures magnitude of earthquakes based on the amplitude of the largest energy wave released by the earthquake. Richter scale readings are suitable for smaller earthquakes; however, because it is a logarithmic scale, the scale does not distinguish clearly the magnitude of large earthquakes above a certain level. Richter scale magnitudes and corresponding earthquake effects are as follows:
2.5 or less—Usually not felt, but can be recorded by seismograph 2.5 to 5.4—Often felt, but causes only minor damage 5.5 to 6.0—Slight damage to buildings and other structures 6.1 to 6.9—May cause a lot of damage in very populated areas 7.0 to 7.9—Major earthquake; serious damage 8.0 or greater—Great earthquake; can totally destroy communities near the epicenter
A more commonly used magnitude scale today is the moment magnitude (Mw) scale. The moment magnitude scale is based on the total moment release of the earthquake (the product of the distance a fault moved and the force required to move it). Moment magnitude roughly matches the Richter scale but provides more accuracy for larger magnitude earthquakes. The scale is as follows:
Great—Mw > 8 Major—Mw = 7.0 - 7.9 Strong—Mw = 6.0 - 6.9 Moderate—Mw = 5.0 - 5.9 Light—Mw = 4.0 - 4.9 Minor—Mw = 3.0 - 3.9 Micro—Mw < 3
August 2019 68
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Intensity Currently the most commonly used intensity scale is the modified Mercalli intensity scale, with ratings defined as follows (USGS, 1989):
I Not felt except by a very few under especially favorable conditions. II Felt only by a few persons at rest, especially on upper floors of buildings. III Felt quite noticeably by persons indoors, especially on upper floors of buildings. Many people do not recognize it is an earthquake. Standing cars may rock slightly. Vibrations similar to the passing of a truck. Duration estimated. IV Felt indoors by many, outdoors by few during the day. At night, some awakened. Dishes, windows, doors disturbed; walls make cracking sound. Sensation like a heavy truck striking building. Standing cars rocked noticeably. V Felt by nearly everyone; many awakened. Some dishes, windows broken. Unstable objects overturned. Pendulum clocks may stop. VI Felt by all; many frightened. Some heavy furniture moved; a few instances of fallen plaster. Damage slight. VII Damage negligible in buildings of good design and construction; slight in well-built ordinary structures; considerable in poorly built or badly designed structures. Some chimneys broken. VIII Damage slight in specially designed structures; considerable damage in ordinary buildings with partial collapse. Damage great in poorly built structures. Fall of chimneys, factory stacks, columns, monuments, walls. Heavy furniture overturned. IX Damage considerable in specially designed structures; well-designed frame structures thrown out of plumb. Damage great in substantial buildings, with partial collapse. Buildings shifted off foundations. Ground Motion Earthquake hazard assessment is also based on expected ground motion. The ground experiences acceleration as it shakes during an earthquake. The peak ground acceleration (PGA) is the largest acceleration recorded by a monitoring station during an earthquake. PGA is a measure of how hard the earth shakes in a given geographic area. It is expressed as a percentage of the acceleration due to gravity (%g). Horizontal and vertical PGA varies with soil or rock type. Instruments called accelerographs record levels of ground motion due to earthquakes at stations throughout a region. These readings are recorded by state and federal agencies that monitor and predict seismic activity. Earthquake hazard assessment involves estimating the annual probability that certain ground motion accelerations will be exceeded and then summing the annual probabilities over a time period of interest. National maps of earthquake shake hazards, which have been produced since 1948, provide information for creating and updating seismic design requirements for building codes, insurance rate structures, earthquake loss studies, retrofit priorities, and land use planning. After thorough review of the studies, professional organizations of engineers update the seismic-risk maps and seismic design requirements contained in building codes (Brown et al., 2001). The USGS updated the National Seismic Hazard Maps in 2014. New seismic, geologic, and geodetic information on
August 2019 69
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
earthquake rates and associated ground shaking were incorporated into these revised maps. The 2014 map, shown in Map 3.2, represents the best available data as determined by the USGS. Building codes that include seismic provisions specify the horizontal force due to lateral acceleration that a building should be able to withstand during an earthquake. Buildings, bridges, highways, and utilities built to meet modern seismic design requirements are typically able to withstand earthquakes better, with less damage and disruption. PGA values are directly related to these lateral forces that could damage “short period structures” (e.g. single-family dwellings). Longer-period response components determine the lateral forces that damage larger structures with longer natural periods (apartment buildings, factories, high-rises, bridges).
Table 3.3 lists damage potential and perceived shaking by PGA factors, compared to the Mercalli scale.
Table 3.3: Mercalli Scale and Peak Ground Acceleration Comparison31 Potential Structure Damage Estimated Modified PGAa Mercalli Scale Resistant Vulnerable (%g) Perceived Shaking Buildings Buildings I Not Felt None None <0.17%
II-III Weak None None 0.17% - 1.4%
IV Light None None 1.4% - 3.9%
V Moderate Very Light Light 3.9% - 9.2%
VI Strong Light Moderate 9.2% - 18%
VII Very Strong Moderate Moderate/Heavy 18% - 34%
VIII Severe Moderate/Heavy Heavy 34% - 65%
IX Violent Heavy Very Heavy 65% - 124%
X - XII Extreme Very Heavy Very Heavy >124%
Effect of Soil Types The impact of an earthquake on structures is a function of ground shaking, distance from the source of the quake, and liquefaction, a secondary effect of an earthquake in which soils lose their shear strength and behave as liquid, damaging structures that derive their support from the soil. Liquefaction involves loose sandy soil with a high water content that undermines the ground’s ability to solidly support building structures during an earthquake.
31 USGS, 2010
August 2019 70
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
A program called the National Earthquake Hazard Reduction Program (NEHRP) creates maps based on soil characteristics to help identify locations subject to liquefaction. Table 3.4 summarizes NEHRP soil classifications. NEHRP Soils B and C typically can sustain ground shaking without much effect, depending on the earthquake magnitude. The areas that are most commonly affected by ground shaking have NEHRP Soils D, E, and F. In general, these areas are also most susceptible to liquefaction.
Table 3.4: NEHRP Soil Classification System Mean Shear NEHRP Velocity to 30 m Soil Type Description (m/s) A Hard Rock 1,500
B Firm to Hard Rock 760-1,500
C Dense Soil/Soft Rock 360-760
D Stiff Soil 180-360
E Soft Clays < 180
F Special Study Soils (liquefiable soils, sensitive clays, organic soils, soft clays >36 m thick)
The USGS has created a soil type map for the Southern California area that provides rough estimates of site effects based on surface geology. NEHRP soil types were assigned to a geologic unit based on the average velocity of that unit. The USGS notes that this approach can lead to some inaccuracy. For instance, a widespread unit consisting of Quaternary sand, gravel, silt, and mud has been assigned as Class C soil types; however, some of the slower soil types in this unit fall under Class D. USGS does not have any way of differentiating units for slower-velocity soils in its digital geologic dataset (USGS, 2017b).
August 2019 71
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Map 3.4: Peek Acceleration (%g) with 10% Probability of Exceedance in 50 years32
Seismic Hazard Profile Community Earthquake Issues Earthquake damage occurs because humans have built structures that cannot withstand severe shaking. Buildings, airports, schools, and lifelines (highways and utility lines) suffer damage in earthquakes and can cause death or injury to humans. The welfare of homes, major businesses, and public infrastructures are very important. Addressing the reliability of buildings, critical facilities, infrastructure, and understanding the potential costs to government, businesses, and individuals as a result of an earthquake are challenges faced by the City. Hospitals
The City of San Juan Capistrano has no major medical facility. Public service agencies and volunteer personnel would be used to assist in the care of the injured. Several of the acute care hospitals in Orange County are expected to be lost due to structural damage. This will impair the number of beds available and create the need for several field hospitals. Although a percentage
32 USGS, 2014
August 2019 72
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
of the remaining beds could be made available by discharging or transferring non-emergency patients, it will probably be necessary to receive an immediate influx of emergency medical aid and/or export some of the seriously injured to out-of-county facilities.
Dams There are no dams located in the City of San Juan Capistrano; however, the City is located in the inundation path of 3 dams: Trampas Canyon Dam, Lake Mission Viejo Dam, and Upper Oso Reservoir. None of these dams are located in the City of San Juan Capistrano, but due to their proximity to the City, there may be a loss of life, damage to property, and other ensuing hazards, as well as the displacement of persons residing in the inundation path. The inundation studies for the three dams are based on the worst-case scenarios. Because of the current design and construction practices, catastrophic dam failure is considered unlikely. Many flood control channels are expected to suffer damage, and pumping stations in coastal communities might fail due to liquefaction. Water Supply Southern California receives imported water via three aqueducts, i.e., the Colorado River, State Water Project, and Los Angeles. The Los Angeles Aqueduct only serves the City of Los Angeles while the other two supply approximately 50% of Orange County's water. The balance comes from a large groundwater basin underlying the northern half of the county, recycled wastewater produced by several local water agencies, and several smaller groundwater basins. The large groundwater basin in the northern county primarily serves the northern county. The majority of South Orange County's water supply is based on imported resources. Water supplies are being increased through recycling, groundwater development, desalination, and conservation. The City of San Juan Capistrano has several wells and reservoirs and has recently constructed a Ground Water Recovery Plant. Following a major earthquake in Southern California, any or all of the aqueducts could be out of service for months depending upon the magnitude and epicenter of the earthquake. Anticipated damage to pipelines, service connections, and reservoirs could take weeks to repair.
Loss of electricity, lack of backup power sources, and physical damage could disable local wells for an indefinite period. To mitigate this threat, the Metropolitan Water District of Southern California, which supplies imported water to Orange County via the Colorado River Aqueduct, recently completed construction of Diamond Valley Lake Reservoir in Riverside County, which nearly doubles the amount of reservoir storage in Southern California. However, the possibility of earthquake damage to miles of water distribution lines required to transport water to Orange County for needed life support, to treat the sick and injured, and for fire suppression activities would still be a major concern to the City of San Juan Capistrano. Sanitation Systems Wastewater treatment facilities could be out of service for months depending on the damage caused by seismic shaking and liquefaction. There is a limited volume of storage available in the wastewater treatment plants; if the treatment facilities cannot be restored before storage is exceeded, the wastewater will require discharge with emergency chlorination to reduce health hazards. Overflow of sewage through manholes and from ponds can be expected due to breakage
August 2019 73
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
in pipes and loss of power. As a result, there would be a danger of excessive accumulation of explosive gas in sewer mains and flow of untreated sewage in some street gutters. House sewer connections may break and or become plugged. There are no wastewater treatment facilities in San Juan Capistrano; the City’s wastewater flows to a facility in the City of Dana Point on Del Obispo Street. Buildings The built environment is susceptible to damage from earthquakes. Buildings that collapse can trap and bury people. Lives are at risk, and the cost to clean up the damages is great. In most California communities, including the City of San Juan Capistrano, a number of buildings were built before the 1993 Northridge earthquake, when building codes were not as strict. In addition, retrofitting is not required except under certain conditions and can be expensive. Therefore, the number of buildings at risk remains high. The California Seismic Safety Commission makes annual reports on the progress of the retrofitting of unreinforced masonry buildings. There are currently 17 unreinforced masonry buildings in the City with several having undergone seismic retrofitting. There are also 17 pre-1972 concrete tilt-up structures within the City. Communications
System failure, overloads, loss of electrical power, and possible failure of some alternate power systems might affect telephone systems. Immediately after the event numerous failures might occur coupled with saturation overloads. It is possible that this will disable up to 80% of the telephone system for one day. In light of the expected situation, emergency planners should not plan on the use of telephone systems for the first few days after the event. It is projected that radio systems will be 40% to 75% effective and microwave systems will be 30% effective or less. Infrastructure Residents in the City of San Juan Capistrano commute frequently by automobiles and public transportation such as buses and light rail. Interstate Highway I-5 and State Route 74 (Ortega Hwy) are critical arteries into and out of San Juan Capistrano. An earthquake can greatly damage bridges and roads, hampering emergency response efforts and the normal movement of people and goods. Damaged infrastructure strongly affects the economy of the community because it disconnects people from work, school, food, and leisure, and separates businesses from their customers and suppliers. Bridge Damage Even modern bridges can sustain damage during earthquakes, leaving them unsafe for use. Some bridges have failed completely due to strong ground motion. Bridges are a vital transportation link - with even minor damages making some areas inaccessible. Because bridges vary in size, materials, location, and design, any given earthquake will affect them differently. Bridges built before the mid-1970's have a significantly higher risk of suffering structural damage during a moderate to large earthquake compared to those built after 1980 when design improvements were made. Much of the interstate highway system was built in the mid to late 1960's. The bridges in the City of San Juan Capistrano are state, county, or privately owned (including railroad bridges). There are 2 recreational bridges, 7 vehicular creek channel bridges, and 1
August 2019 74
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
vehicular rail corridor bridge in the City, along with 10 freeway bridges crossing Interstate 5. Cal Trans has retrofitted most bridges on the freeway systems; however, there are still some county maintained bridges that are not retrofitted. The Federal Highway Administration (FHWA) requires that bridges on the National Bridge Inventory be inspected every 2 years. Damage to Lifelines Lifelines are the connections between communities and outside services. They include water and gas lines, transportation systems, electricity, and communication networks. Seismic shaking and amplification can cause pipes to break open, power lines to fall, roads and railways to crack or move, and radio and telephone communication to cease. Disruption to transportation makes it especially difficult to bring in supplies or services. Lifelines need to be usable after an earthquake to allow for rescue, recovery, and rebuilding efforts and to relay important information to the public. Businesses Seismic activity can cause great loss to businesses, both large-scale corporations and small retail shops. When a company is forced to stop production for just a day, the economic loss can be tremendous, especially when its market is at a national or global level. Seismic activity can create economic loss that presents a burden to large and small shop owners who may have difficulty recovering from their losses. Forty percent of businesses do not reopen after a disaster, and another twenty-five percent fail within one year according to the Federal Emergency Management Agency (FEMA). Similar statistics from the United States Small Business Administration indicate that over ninety percent of businesses fail within two years after being struck by a disaster. Individual Preparedness Because the potential for earthquake occurrences and earthquake related property damage is relatively high in the City of San Juan Capistrano, increasing individual preparedness is critically important. Strapping down heavy furniture, water heaters, and expensive personal property, as well as being earthquake insured, and anchoring buildings to foundations are just a few steps individuals can take to prepare for an earthquake. Death and Injury Death and injury can occur both inside and outside of buildings due to structural collapse, falling equipment, falling furniture, broken glass, and dangerous debris. Downed power lines, broken water pipes, and leaking gas lines can also endanger human life. Fire Although total collapse of fire stations is not expected, possible disruption of utilities and loss of power might create major problems. There could be numerous fires due to disruption of power and natural gas networks. Many connections to major water sources may be out, and water reserves might be required. First responders are expected to assess the area to establish what is needed to determine response and recovery needs. Operations may take days because of the disruption of transportation routes for fire department personnel and equipment. The City
August 2019 75
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
contracts with Orange County Fire Authority for fire services and can expect the equipment located in the City at the time of the event to be available for the City.
Downed power lines or broken gas mains can trigger fires. When fire stations suffer building or lifeline damage, quick response to extinguish fires is less likely. Furthermore, major incidents will demand a larger share of resources, and initially smaller fires and problems will receive little or insufficient resources in the initial hours after a major earthquake event. Loss of electricity may cause a loss of water pressure in some communities, further hampering fire fighting ability. Debris After damage to a variety of structures, much time is spent cleaning up brick, glass, wood, steel or concrete building elements, office and home contents, and other materials. Developing a strong debris management strategy is essential in post-disaster recovery. Occurrence of a disaster does not exempt the City of San Juan Capistrano from compliance with the California Integrated Waste Management Act, (AB 939) regulations. Secondary Effects of Seismic Shaking
Seismic-induced ground shaking can result in secondary effects such as landslides, rockfalls, and dam failure, which could result in flooding and/or a seiche, which is an oscillation of water in a reservoir. Seismic shaking and liquefaction from earthquakes can cause major damage to nearly all utility systems, both aboveground and underground. Utility poles may fall, cutting off electrical and telephone service. Gas lines may rupture, causing fires. Water lines may rupture and prevent access to potable water. Any one or a combination of these occurrences would prevent the response and recovery process from taking place and would place lives and property at risk. Those utilities located within or in close proximity to faults and liquefaction areas are potentially susceptible to these hazards, and failure of these facilities could further exacerbate emergency response and recovery.
Seismic Liquefaction Liquefaction is the conversion of water-saturated soil into a fluid-like mass. This can occur when loosely packed, waterlogged sediments lose their strength in response to strong shaking. Liquefaction effects may occur along the shorelines of the ocean, rivers, and lakes, and they can also happen in low-lying areas away from water bodies in locations where the ground water is near the earth’s surface. Tsunamis Tsunamis are another secondary effect of earthquakes that threaten coastal communities. Tsunamis are ocean waves triggered by large earthquakes that occur near or under the ocean, volcanic eruptions, submarine landslides, and by onshore landslides in which large volumes of 33 debris fall into the water.
33 USGS, Science for a Changing World, Natural Hazards, What are Tsunamis?, https://www.usgs.gov/faqs/what-are-tsunamis?qt- news_science_products=0#qt-news_science_products
August 2019 76
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
No portion of The City of San Juan Capistrano lies within a Tsunami inundation zone. While San Juan Capistrano would not be inundated by a tsunami, the City may be requested to provide support for displaced residents from other cities. Location and Extent of Earthquake Hazard
There are several major faults and fault systems within Southern California and in close proximity to the City, placing them in an area of high seismic risk and high probability of occurrence. Of these faults, the Newport-Inglewood Fault Zone presents the highest risk of damage to the City of San Juan Capistrano.
Table 3.5: Active Earthquake Faults Near San Juan Capistrano and their Magnitude Potential Fault Name Distance to San Juan Capistrano Magnitude Range
San Andreas Fault Zone Approximately 50 miles (North/Northeast) 6.8-8.0
Newport-Inglewood Fault Zone Less Than 5 miles (Southwest) 6.0-7.4
Whittier-Elsinore Fault Approximately 19 miles (Northeast) 6.0-7.5
San Joaquin Hills Fault Approximately 7 miles (Northwest) Up to 7.3
Elysian Park Fold and Thrust Belt Approximately 30 miles (Northwest) 6.0-7.0
August 2019 77
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Map 3.5: Earthquake Faults in Proximity to San Juan Capistrano
August 2019 78
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) Active Earthquake Faults in Southern California
Table 3.6: Active Faults in Proximity to the City of San Juan Capistrano34 Distance to Fault Magnitude Description San Juan Name Range Capistrano
The San Andreas Fault is the dominant active fault in California; it is the main element of the boundary between the Pacific and North American tectonic plates. The longest and most publicized fault in California, it extends approximately 650 miles from Cape Mendocino in northern California to east of San Bernardino in southern California. This fault was the source of the 1906 San Francisco earthquake, which resulted in some San 700 deaths and millions of dollars in damage. It is the southern section of Approx. Andreas this fault that is currently of greatest concern to the scientific community. 50 miles 6.8-8.0 Fault Geologists can demonstrate that at least eight major earthquakes (Richter (N/NE) Zone magnitude 7.0 and larger) have occurred along the Southern San Andreas Fault in the past 1,200 years with an average spacing in time of 140 years, plus or minus 30 years. The last such event occurred in 1857 (the Fort Tejon earthquake). Based on that evidence and other geophysical observations, the Working Group on California Earthquake Probabilities (SCEC, 1995) has estimated the probability of a similar rupture (magnitude 7.8) in the next 30 years (1994 through 2024) to be about 50%.
Newport- The Newport-Inglewood Fault is considered the second most active fault in Less Than Inglewood California. It extends from the Santa Monica Mountains southeastward through the western part of Orange County to the offshore area near 5 miles 6.0-7.4 Fault Newport Beach and was the source of the destructive 1933 Long Beach (Southwest) Zone earthquake (magnitude 6.4). The Whittier-Elsinore Fault is a right-lateral northwest trending strike-slip fault approximately 40 km in length with some reverse slip. Located in the northeast part of Orange County, this fault has not produced major Whittier- earthquakes within historic times, although a number of tremors in the 3.0 Approx. to 4.5 Richter magnitude range have been measured. In September of Elsinore 6.0-7.5 1987, a 6.1 earthquake occurred near this fault in the City of Whittier. 19 miles Fault Geologic studies indicate that any portion of the fault is capable of (Northeast) producing an earthquake up to 6.9 Richter magnitude, which could result in “severe” damage in Orange County. The last major earthquake on this fault occurred in 1910 (magnitude 6.0). The California Division of Mines and Geology stated that the San Joaquin San Hills blind-thrust fault appears to be active and runs approximately 24 miles Approx. south of Huntington Beach to the north of Dana Point beneath coastal Joaquin Up to 7.3 mesas and the San Joaquin Hills. A measure event on this fault would be 7 miles Hills Fault expected to cause significant damage with the County, somewhat similar to (Northwest) that caused by an event on the Newport-Inglewood fault. Elysian Park Fold The Elysian Park belt was the site of the 1987 Whittier Narrows Approx. earthquake. This fault is located approximately 6 to 10 miles underground and 6.0-7.0 and approximately 10 miles to the north under the City of Brea. The 1987 30 miles Thrust earthquake was a magnitude of 6.7. (Northwest) Belt
34 Southern California Earthquake Date Center, Significant Earthquakes and Faults, Historical Earthquakes & Significant Faults in Southern CA
August 2019 79
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Union of Two Earthquake Faults According to a report by Julian C. Lozos of Cal State Northridge, and published in 2016 by the American Association for the Advancement of Science (AAAS), a joint rupture of the San Jancinto and San Andreas faults caused the magnitude 7.5 earthquake of 1812, which destroyed Mission San Juan Capistrano’s Great Stone Church and killed more than 40 people attending mass.35
Map 3.6: Union of Two Earthquake Faults
Past Occurrence of Earthquakes
Past seismic events indicate that the city has been free of major damaging earthquakes for at least 80 years. However, a number of historic earthquakes affecting Orange County, and Southern California in general, have impacted San Juan Capistrano in varying degrees from nonstructural damage (toppling of building contents) to minor structural damage.
35 American Association for the Advancement of Science (AAAS), Union of Two Faults, Julian Lozos, Cal State Northridge, Science Advances
August 2019 80
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Table 3.7: Historic Earthquake Events36 Date Fault/Location Impact/Property Damage Newport- 7/1/1855 Magnitude 6.0. This earthquake was felt from San Bernardino to Santa Barbara. Inglewood Magnitude 7.9 (largest earthquake in California history). Heavy property loss at Ft. Tejon, 1/9/1857 San Andreas one death, was felt from Marysville south to San Diego and east to Las Vegas, Nevada. Strong shaking lasted from 1 to 3 minutes. Newport- 6/21/1920 Magnitude 4.9. Minor property damage to a limited area of Inglewood. Inglewood Magnitude 6.3. Property damage estimated at $8 million. 13 deaths, was felt as far north as 6/29/1925 Santa Barbara the central coast region between Santa Maria and Nipomo, and as far east as Corona and San Bernardino.
Newport- Magnitude 6.4, Intensity VIII. Property damage estimated at $40 million. 115 deaths, was felt almost everywhere in the 10 southern counties of California and at some points farther 3/11/1933 Inglewood to the northwest and north in the Coast Range, the San Joaquin Valley, the Sierra Nevada, (Long Beach) and the Owens Valley, as well as Baja, California. Torrance- 10/21/1941 Magnitude 4.8, Intensity VII. No deaths reported; property damage estimated at $100,000. Gardena San Fernando Magnitude 6.6, Intensity XI. Property damage estimated at $505 million. 65 deaths, more 2/9/1971 than 2,000 injuries, felt throughout Southern California and into western Arizona and (Sylmar) southern Nevada. North Palm Magnitude 6.1, Intensity VII. Property damage estimated at $6 million. 40 injuries in the 7/8/1986 North Palm Springs area. The earthquake disrupted electrical and telephone service and Springs caused failure of 2 pumping stations in the Metropolitan Water District.
Whittier Magnitude 5.9, Intensity VI-VIII. Property damage estimated at $358 million. 8 deaths and 10/1/1987 several hundred injuries. A large aftershock registering magnitude 5.6 occurred three days Narrows later, causing one additional death and additional property damage. Magnitude 6.7, Intensity IX. Responsible for at least 61 deaths, 6,500 injuries, destroying/seriously damaging more than 1,000 buildings, and moderately damaging 1/17/1994 Northridge 11,000 structures throughout the Los Angeles Basin, and leaving 20,000 people homeless. Estimated damages as high as $20 billion; one of the costliest natural disasters in American history. Magnitude 5.5, Intensity VI. Felt at cities in Orange and Los Angeles Counties. No deaths, 7/29/2008 Chino Hills but considerable damage to numerous structures throughout the area.
Magnitude 5.1, felt at cities in Orange and Los Angeles Counties. No deaths, but moderate 3/28/2014 La Habra damage to structures throughout the area. $10.5 million in damage and cost. No State Emergency Proclamation.
The first main shock (now deemed to be a foreshock) occurred on July 4 at 10:33 a.m. north/northeast of Ridgecrest, California. The M 7.1 quakes struck on July 5 at 8:19 p.m. PDT approximately 6 miles to the northwest. Relatively minor damage resulted from the initial foreshock, though some building fires were reported in Ridgecrest near the epicenter. 7/4/2019 Ridgecrest The main quake on July 5 cut power to at least 3,000 residents in Ridgecrest. Effects were felt across much of Southern California, parts of Arizona and Nevada, as far north as the San Francisco Bay Area and Sacramento, and as far south as Baja California, Mexico. An estimated 20 million people experienced the foreshock, and approximately 30 million people experienced the main shock.
36 USGS Earthquake Hazards Program data. http://earthquake.usgs.gov/earthquakes/states/historical_state.php#california
August 2019 81
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) Past Occurrences of Seismic Liquefaction
Prior instances of earthquakes and liquefaction have not occurred within the city; however, areas of San Juan Capistrano are situated on soil with liquefaction potential. The most recent damaging earthquake events affecting Southern California were the1994 Northridge Earthquake, and the 2014 La Habra Earthquake. On March 20, 2014 a 5.1 magnitude earthquake struck La Habra at 9:09 p.m. The epicenter was 1 mile east of La Habra. The earthquake WAS FELT IN Ker, San Bernardino, Orange, Ventura, Riverside, San Diego, and Los Angeles Counties. There wer e no reported injuries.
At 4:31 A.M on Monday, January 17, a moderate but very damaging earthquake with a magnitude of 6.7 struck the San Fernando Valley. In the following days and weeks, thousands of aftershocks occurred, causing additional damage to affected structures. Approximately 61 people were killed and more than 6,500 people seriously injured. Existing Earthquake Damage Mitigation Activities Existing mitigation activities include current mitigation programs, including the City’s 2004 Local Hazard Mitigation Plan, and activities that are being implemented locally and by county, regional, state, or federal agencies or organizations. City of San Juan Capistrano Codes Implementation of earthquake mitigation policy most often takes place at the local government level. The City of San Juan Capistrano Engineering and Building Department enforces building codes pertaining to earthquake hazards. The following sections of the Uniform Building Code (UBC) address the earthquake hazard:
1605,1 (Distribution of Horizontal Sheer) 1605.2 (Stability against Overturning) 1626 (Seismic) 1605.3 (Anchorage) 1632, 1633, 1633.9 deal with specific earthquake hazards
The City of San Juan Capistrano Planning Department enforces the zoning and land use regulations relating to earthquake hazards. Generally, these codes seek to discourage development in areas that could be prone to flooding, landslide, wildfire, and/or seismic hazards. Developers in hazard-prone areas may be required to retain a qualified professional engineer to evaluate level of risk on the site and recommend appropriate mitigation measures. Coordination Among Building Officials The City of San Juan Capistrano Building Code sets the minimum design and construction standards for new buildings. In September 2002 (FMC Ordinance 6909), the City of San Juan Capistrano adopted the most recent seismic standards in its building code, which requires that new buildings be built at a higher seismic standard (2002 California Building Code).
Since 1968 (with Zaheer Plan), the City of San Juan Capistrano also requires that site-specific seismic hazard investigations be performed for new essential facilities, major structures, hazardous
August 2019 82
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
facilities, and special occupancy structures such as schools, hospitals, and emergency response facilities. Probability of Future Occurrence
The City of San Juan Capistrano is located in an area susceptible to a high potential for shaking intensity and liquefaction damage. The probability that liquefaction will occur in the future in San Juan Capistrano is dependent on many factors including the intensity of ground shaking, location of the earthquake, and subsurface conditions (including groundwater elevation).
To clarify the extent of future earthquake risk, a partnership between the United States Geological Survey, California Geologic Survey, and Southern California Earthquake Center was formed in September 2004 to provide a uniform forecast. Known as the Working Group on California Earthquake Probabilities, this group evaluated and systemized currently available historic and paleoseismic information to produce a probabilistic seismic hazards analysis to indicate the type of future earthquakes. One product of this analysis is a method of estimating the probability of ground shaking. The 30-year probability of an M ≥ 6.7 earthquake on the southern segment of the San Andreas Fault in Southern California is 97% and a probability of 50% that a M7.8 earthquake could occur.37
For those areas of the city identified with a high and very high liquefaction potential, it should be anticipated that potential damage could occur under future earthquakes. Potential Impact
Following major earthquakes, extensive search and rescue operations may be required to assist trapped or injured persons. Emergency medical care, food, and temporary shelter would be required for injured or displaced persons. In the event of a truly catastrophic earthquake, identification and burial of the fatalities would pose difficult problems. Mass evacuation may be essential to save lives, particularly in areas below dams. Many families could be separated if the earthquake should occur during working hours. Emergency operations could be seriously hampered by the loss of communication and damage to transportation routes within, to, and out of the disaster area and by the disruption of public utilities and services. Unless properly secured, hazardous materials can be released, causing significant damage to the environment and the people. Extensive federal assistance could be required and could continue for an extended period of time. A significant earthquake (5.0 or greater) in the Orange County area or the region can strike without warning, and may create cascading effects. Earthquakes can cause large and sometimes disastrous landslides and mudslides. Any steep slope is vulnerable to slope failure, often as a result of loss of cohesion in clay-rich soils. Earthquakes can also cause dam failures38.
37 California Geological Survey. http://gmw.consrv.ca.gov/shmp/pdf_maps_so.html 38 County of Orange & Orange County Fire Authority Local Hazard Mitigation Plan November 2015
August 2019 83
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) Critical Facilities at Risk
Twenty nine of the City’s fifty critical facilities are located in areas the USGS has identified as potential liquefaction zones. Table 3.8 lists the critical facilities located in potential liquefaction zones and Map 3.7 identifies the locations of those facilities. Based on available data on the City’s insured values of the structure and contents of each facility, the City has a potential aggregate financial risk to earthquake induced liquefaction damage of approximately 68 million dollars.
Table 3.8: Critical Facilities in the Potential Liquefaction Zones Replacement Contents Potential Loss Map # Facility Value Value 1 City Hall $6,000,000 $3,000,000 $9,000,000 2 Utilities Yard $859,760 $667,666 $1,527,426 3 Dance Hall/Police Services $675,137 $37,859 $712,996 4 Utilities Department Offices $505,150 $867,709 $1,372,859 5 OCFA Fire Station #7 * * * 6 SJC City Gym/Boys & Girls Club $4,374,080 $10,000 $4,384,080 8 Groundwater Recovery Plant (GWRP) $27,042,929 $0 $27,042,929 9 Public Works Yard $525,574 $822,313 $1,347,887 10 Old Fire Station Complex $3,208,197 $34,364 $3,242,561 11 SJC Community Center $7,367,194 $440,523 $7,807,717 12 San Juan Capistrano Regional Library $7,800,083 $50,000 $7,850,083 13 Mariners Church Ocean Hills * * * 14 South Cooks Well na na na 15 JSerra Catholic High School * * * 17 St. Margaret's Episcopal School * * * 29 CVWD Well #1 na na na 30 SJBA Well #2 na na na 31 Tirador Well na na na 32 Kinoshita Well na na na 33 Well #5A na na na 34 SJBA Well #4 na na na 35 North Open Space Well $0 $1,292,665 $1,292,665 43 Rosenbaum Well #1 $0 $1,292,665 $1,292,665 44 Dance Hall Well na na na 45 Mission Street Well na na na 46 Strawberry Hill Pump Station na na na 47 Rosenbaum Lift Station $0 $132,823 $132,823 48 Master Meter CM10 ETM na na na 50 SC-04 Flow Station $152,893 $996,160 $1,149,053 Total Potential Losses $58,510,997 $9,644,747 $68,155,744 Replacement value information based on City insured values for each facility. * - Not City Owned na - No Data Available
August 2019 84 City of San Juan Capistrano Local Hazard Mitigation Plan Map 3.7: Liquefaction Zones within the City of San Juan Capistrano
Number Name Address 1 City Hall 32400 Paseo Adelanto 2 Utilities Yard 32450 Paseo Adelanto 3 Dance Hall\Police Services 32506 Paseo Adelanto 4 Utilities Department Offices 32450 Paseo Adelanto 5 OCFA Fire Station #7 31865 Del Obispo Street 6 SJC City Gym/Boys & Girls Club 25925 Camino Del Avion 8 Groundwater Recovery Plant (GWRP) 32470 Paseo Adelanto 9 Public Works Yard 32450 Paseo Adelanto 10 Old Fire Station Complex 31421 La Mantanza Street 11 SJC Community Center 1 Via Positiva 12 San Juan Capistrano Regional Library 31495 El Camino Real 13 Mariners Church Ocean Hills 32222 Del Obispo Street 14 South Cooks Well 27396 Calle Arroyo 15 JSerra Catholic High School 26351 Junipero Serra Road 17 St. Margaret's Episcopal School 31641 La Novia Avenue 29 CVWD Well #1 32510 Del Zura 30 SJBA Well #2 26372 Paseo Toscana 31 Tirador Well 27122 Paseo Tirador 32 Kinoshita Well 32784 Alipaz Street 33 Well #5A 27802 Calle Arroyo 34 SJBA Well #4 32703 Vivente De Marlita 35 North Open Space Well 30291 Camino Capistrano 43 Rosenbaum Well #1 29688 Rancho Viejo Road 44 Dance Hall Well 32470 Paseo Adelanto 45 Mission Street Well 26601 Mission Street 46 Strawberry Hill Pump Station 31261 El Horno Street 47 Rosenbaum Lift Station 29688 Rancho Viejo Road 48 Master Meter CM10 ETM 28901 Camino Capistrano 50 SC-04 Flow Station Ortega Hwy & Antonio Pkwy
August 2019 85
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) Climate Change Considerations
The link between climate change impacts and seismic hazards is indirect. One possible consideration is that anticipated changes to precipitation regimes and hydrological patterns could result in a change to groundwater levels. Since liquefaction is dependent on the presence of shallow subsurface water, an increase in groundwater levels could occur due to new precipitation patterns. The potential change in shallow subsurface water conditions could expand the potential liquefiable areas within the city, increasing the risk of future damage to additional structures in the city. In contrast, a reduction in precipitation as a result of climate change could reduce groundwater levels in the future, which could reduce liquefaction potential in the city. Summary Vulnerability/Risk Assessment
The effects of earthquakes span a large area, and large earthquakes occurring in many parts of the Southern California region would likely be felt throughout the region. However, the degree to which the earthquakes are felt and the damages associated with them may vary. At risk from earthquake damage are large stocks of old buildings and bridges, high-tech and hazardous materials facilities, extensive sewer, water, and natural gas pipelines, earth dams, petroleum pipelines, and other critical facilities and private properties located in the City. Secondary earthquake hazards such as, liquefaction, ground shaking, amplification, and earthquake-induced landslides, are just as devastating as the earthquake.
August 2019 86
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) Epidemic and Vector Bourne Disease General Background The following hazard profile describes commonly recognized human health hazards. In San Juan Capistrano, the Orange County Mosquito and Vector Control District works to reduce the risk of diseases spread by insects and animals, and the Orange County Public Health Care Agency investigates individual cases and outbreaks of reported communicable diseases. Definitions
Epidemic - The spread of an infectious disease beyond a local population, reaching people in a wider geographical area. Several factors determine whether an outbreak will become an epidemic: the ease with which the disease spreads from vectors, such as animals to people, and the ease with which it spreads from person to person.
Influenza - A viral infection that attacks the respiratory system, commonly called the flu.
Pandemic - A worldwide epidemic.
Vector - An organism (such as an insect or rodent) that transmits pathogens that cause disease.
Vector-Borne Illness - Diseases transmitted to people from insects and other animals. These include, but are not limited to, Hanta Virus, Plague, Tularemia, Lyme Disease, West Nile Virus, and the Zika Virus. Epidemic and Vector Bourne Disease Hazard Profile Community Issues
Disease and pest management hazards occur when an undesirable type of organism (including insects and pathogens such as bacteria) inhabits an area in a manner that causes serious harm to plants, animals, or humans. In some communities, diseases can do significant harm to agricultural operations or cause widespread devastation to forests, which may have safety and economic impacts. Influenza The most widespread, potentially serious disease known to occur in Orange County is influenza, which commonly occurs during winter. The virus that causes influenza is spread through the air, usually by coughing or sneezing, and may also be spread by touching surfaces, which may have been contaminated with the pathogen. The symptoms of influenza may include fever, headache, runny or stuffy nose, fatigue, and gastrointestinal distress. In some instances, influenza can be severe; The Center for Disease Control (CDC) estimates that from October 1, 2018 and February 2, 2019 there have been 13.2 – 15.2 million flu illnesses, 6.2-7.2 million flu medical visits, and
August 2019 87
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
155,000-186,000 flu hospitalizations.39 The Centers for Disease Control and Prevention (CDC) recommends a yearly flu vaccine for everyone 6 months of age and older as the first and most important step in protecting against this serious disease. Getting the flu vaccine as soon as it becomes available each year is best. It takes about two weeks after vaccination for antibodies to develop in the body and provide protection against the flu. Influenza seasons are unpredictable and can begin as early as October. Fatalities from the flu are most common among the young, the elderly, and those with weakened immune systems.
Although vaccines for influenza are often widely available, a primary health concern is that of a pandemic, which would affect a large number of people and for which there may not be an effective vaccine or treatment options. An influenza pandemic most recently occurred in 2009, when the H1N1 version of the disease (commonly known as the “swine flu”) killed an estimated 284,500 people worldwide, on top of fatalities caused by all other versions of influenza. Most recently, the Centers for Disease Control and Prevention and World Health Organization have been monitoring the H5N1 strain of Avian Influenza across the globe. This strain infects birds, poultry, and humans; however, no reported infections have occurred within the United States. Areas of the globe where confirmed infections/outbreaks have occurred include parts of Asia and the Middle East40. West Nile Virus The second primary disease risk, as identified by the Orange County Health Care Agency, is West Nile virus. West Nile virus (WNV) is the leading cause of mosquito-borne disease in the continental United States. It is most commonly spread to people by the bite of an infected mosquito. Cases of WNV occur during mosquito season, which starts in the summer and continues through fall. West Nile virus attacks the central nervous system, causing severe illness and potentially a coma or death. There are no vaccines to prevent or medications to treat WNV in people. Fortunately, most people infected with WNV do not feel sick. About 1 in 5 people who are infected develop a fever and other symptoms. About 1 out of 150 infected people develop a serious, sometimes fatal, illness.41 According to the Orange County Health Care Agency, there were 38 reported infections and 4 deaths in 2017 due to West Nile virus in Orange County. On November 19, 2018, there were 11 human infections and one death reported in Orange County.42 Severe Acute Respiratory Syndrome (SARS) In the past, the Orange County Health Care Agency has also identified Severe Acute Respiratory Syndrome (SARS) as a primary health risk. The disease first appeared in China in November 2002 and spread to a number of other countries, including the United States, before the outbreak was declared contained in July 2003. The worldwide number of probable SARS infections reached 8,273 people, including 27 in the United States (only eight cases were confirmed). No known deaths occurred in the United States, although globally the disease killed 775 people. There have been no new reported cases of SARS since 2004.
39 Center for Disease Control and Prevention, https://www.cdc.gov/flu/index.htm 40 Center for Disease Control and Prevention, http://www.flu.gov/about_the_flu/h5n1/index.html 41 Center for Disease Control and Prevention, https://www.cdc.gov/westnile/ 42 Orange County Public Health Care Agency, http://www.ochealthinfo.com/gov/health/phs/about/dcepi/epi/dip/prevention/disease_listing_a_z
August 2019 88
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Measles Measles is a highly contagious and potentially severe disease that causes fever, rash, cough, and red, watery eyes. Measles spreads very easily by air and by direct contact with an infected person. Measles is contagious from approximately 4 days before the rash appears through 4 days after the rash appears. Exposed people who have not had measles or been vaccinated generally develop symptoms approximately 8-12 days after exposure to measles, with rash appearing an average of 14 days but up to 21 days after that of the initial case.43
Measles was eliminated from the United States in 2000, meaning that ongoing continuous transmission no longer occurs here. However, measles cases can still be imported from areas that have measles circulating and can spread quickly in communities with unvaccinated persons. Maintaining high vaccination rates is vital to preventing outbreaks of disease in our community. Zika Virus Zika virus was first discovered in 1947 and is named after the Zika Forest in Uganda. In 1952, the first human cases of Zika were detected, and since then, outbreaks of Zika have been reported in tropical Africa, Southeast Asia, and the Pacific Islands. Zika outbreaks have probably occurred in many locations. Before 2007, at least 14 cases of Zika had been documented, although other cases were likely to have occurred and were not reported. Because the symptoms of Zika are similar to those of many other diseases, many cases may not have been recognized. There is no vaccine or medicine for Zika. It is spread mostly by the bite of an infected Aedes species mosquito (Ae. aegypti and Ae. albopictus). These mosquitoes are aggressive daytime biters but also bite at night. Zika can be passed through sex from a person who has Zika to his or her sex partners. Zika can be passed from a pregnant woman to her fetus. Zika infection during pregnancy can cause a birth defect of the brain called microcephaly and other severe fetal brain defects. Other problems have been detected among fetuses and infants infected with Zika virus before birth, such as defects of the eye, hearing deficits, and impaired growth. There have also been increased reports of Guillain-Barré syndrome, an uncommon sickness of the nervous system, in areas affected by Zika. The mosquitoes that transmit Zika virus (Aedes aegypti or Aedes albopictus) have been sporadically detected in California, and both mosquitoes were found in parts of Orange County in 2016; however, Zika virus is not circulating in California. Returning travelers from a country with Zika transmission should avoid mosquito bites for the first week of illness to avoid transmitting the virus to others in the community.44 Location and Extent of Epidemic and Vector Bourne Disease Hazards All of San Juan Capistrano is susceptible to the human health hazards discussed in this chapter. While some hazards, such as the West Nile Virus and Lyme disease, can have a geographic presence within the
43 Orange County Public Health Care Agency, http://www.ochealthinfo.com/gov/health/phs/about/dcepi/epi/azdiseases/measles.asp 44 Orange County Public Health Care Agency, http://www.ochealthinfo.com/phs/about/dcepi/epi/dip/prevention/disease_listing_a_z/zika
August 2019 89
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
City, other diseases can cause exposure to the planning area from outside the local region. Local residents who travel can become exposed to diseases while abroad and bring the diseases back with them, potentially placing the region at risk for exposure. It is difficult to map the extent of human-health hazards compared to others, such as floods, wildfires, and dam failures. Past Occurrences of Epidemic and Vector Bourne Disease West Nile Virus
West Nile Virus infections also range significantly from year to year. The virus first appeared in California in 2003 and had spread to all counties in the state by 2004. Since the disease arrived, the number of reported West Nile virus infections in humans in Orange County has ranged annually from 0 to 71. In 2018, Orange County saw 11 reported human infections of West Nile Virus. Currently there have been no new cases of West Nile Virus reported this year in Orange County.45 Influenza
As influenza strains and their virulence change each year, the number of people severely affected by influenza can vary widely. In Orange County, there were 226 cases of severe illness and 57 deaths associated with H1N1 through August 9, 2010.46 The 2017-2018 influenza activity in Orange County was higher than reported in the past five flu seasons Influenza A/H3 viruses predominated, although A/H109 and B viruses were also identified in circulation More influenza-related deaths were reported than any season since the 2009 pandemic Three pediatric influenza-associated deaths were reported; none received the 2017-18 influenza vaccine
45 http://www.ochealthinfo.com/gov/health/phs/about/dcepi/epi/dip/prevention/disease_listing_a_z 46 Summary Report of the Orange County Health Care Agency Response to Pandemic H1N1 2009 Influenza
August 2019 90
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Figure 3.2: 2017-18 Influenza Seasons Summary
Source: OC Health Care Agency, Eye on Influenza, 2017-18 Influenza Update Measles
Most recently, in December 2014, an outbreak of measles occurred within California originating in Orange County. During this outbreak, 131 measles cases were reported to the California Department of Public Health (CDPH) that were likely linked to this outbreak. Forty-two cases were directly linked to an initial exposure in December at the Disneyland Theme Parks in Anaheim, California. As of April 17, 2015, the CDPH announced that the measles outbreak that began in December 2014 was over.47
Table 3.9: Orange County Measles Cases (as of 5/17/19)48 Orange County Measles Cases (as of 5/17/2019)
2012 2013 2014 2015 2016 2017 2018 2019
0 1 23 35 0 3 1 4
47 California Department of Public Health, www.cdph.ca.gov/Programs/CID/DCDC 48 Orange County Public Health Care Agency, http://www.ochealthinfo.com/gov/health/phs/about/dcepi/epi/azdiseases/measles.asp
August 2019 91
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) Zika
Table 3.10: Zika Virus Infections in California, 2015-2019 (as of February 1, 2019)49 Zika virus infections in California, 2015-2018d (as of February 1, 2019) County Travel-associated e Travel-associated e Travel-associated e 2015-2016 2017 2018 Alameda 35f 10f 7f (City of Berkeley) (3) (3) (2) Butte 2 0 0
Contra Costa 26 4 2
Fresno 7 1 0
Humboldt 2 0 0
Imperial 0 1 0
Kern 5 1 0
Kings 1 0 0
Lake 1 0 0
Los Angeles 114g 22g 18g (City of Long Beach) (6) (1) (5) (Pasadena) (1) (0) (1) Marin 9 2 1
Mendocino 0 1 0
Merced 3 0 1
Monterey 5 1 0
Napa 3 0 0
Nevada 1 0 0
Orange 31 12 4
Placer 1 0 0
Riverside 14 4 1
Sacramento 7 0 0
San Benito 1 0 0
49 California Department of Public Health, Monthly Update on Number of Zika Infections in California, February 1, 2019
August 2019 92
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Zika virus infections in California, 2015-2018d (as of February 1, 2019) County Travel-associated e Travel-associated e Travel-associated e 2015-2016 2017 2018 San Bernardino 18 7 0
San Diego 85h 20 7 San Francisco 29 11 9
San Joaquin 7 1 0
San Luis Obispo 1 0 0
San Mateo 13 2 5
Santa Barbara 8 2 0
Santa Clara 36 14 8
Santa Cruz 3 0 0
Solano 3 2 1
Sonoma 11 5 2
Stanislaus 4 0 0
Tulare 5 2 0
Ventura 9 0 0
Yolo 6 1 1
Yuba 3 0 0 a The number of completed pregnancies include those that ended in a live birth, miscarriage, stillbirth, or termination b Birth defects reported include those that have been detected in infants infected with Zika before, during, or shortly after birth, including microcephaly, calcium deposits in the brain indicating possible brain damage, excess fluid in the brain cavities and surrounding the brain, absent or poorly formed brain structures, abnormal eye development, or other problems resulting from damage to the brain that affects nerves, muscles, and bones, such as clubfoot or inflexible joints, and confirmed hearing loss c Includes miscarriage, stillbirths, and terminations with evidence of the birth defects mentioned d Total number includes laboratory-confirmed and probable infections as defined by the CSTE Position Statement e Persons exposed through travel to an affected area or contact with a traveler f Includes eight residents of the City of Berkeley g Includes twelve residents of the City of Long Beach and two residents of Pasadena h Includes one non-resident
August 2019 93
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) Existing Epidemic and Vector Bourne Disease Mitigation Activities Orange County Mosquito and Vector Control District
The Orange County Mosquito and Vector Control District provides San Juan Capistrano services to control vectors and vector-borne diseases. The District's programs are based on scientifically planned management tactics and control strategies that reduce the abundance of vectors in a timely manner. This method is referred to as “integrated vector management” (IVM).
IVM incorporates five basic methods:
Public information and education Mosquito and vector surveillance Biological control Physical control Microbial and chemical control
Orange County Public Health Care Agency
The Orange County Public Health Care Agency’s Epidemiology and Assessment Unit employs medical directors, public health nurses, and epidemiologists to investigate individual cases and outbreaks of reported communicable disease per the State of California Code of Regulations. The Unit monitors disease trends, and often provides current statistics and other information to doctors, hospitals, the public, and news media. Probability of Future Occurrence It is likely that influenza and West Nile virus infections will continue to occur in Orange County. Influenza viruses change rapidly and have proven virtually impossible to eradicate, although vaccination and basic hygiene rules can substantially reduce the odds of being infected. West Nile virus has proven similarly challenging to wipe out, although the disease remains relatively rare and can be constrained by reducing the risk of mosquito bite through insect repellents, the use of screens and protective clothing, and draining pools of stagnant water where mosquitoes breed. Potential Impact The severity of the human health hazard varies from individual to individual. Typically, young children and older adults are more susceptible to acquiring communicable diseases due to developing or diminishing immune systems or experiencing adverse effects from extreme weather conditions. These populations often experience the most severe of symptoms, as their immune systems are not capable of fighting off infection or efficiently regulating temperature. In general, severity varies depending on the pathology of the disease, the health of the infected, and the availability of treatments for alleviating symptoms or curing the disease.
All citizens in the planning area could be susceptible to the human health hazards discussed in this chapter. A large outbreak or epidemic, a pandemic, or a use of biological agents as a weapon of mass destruction could have devastating effects on the population. While all of the population in the planning
August 2019 94
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) area is at risk to the human health hazards discussed in this chapter, the young and the elderly, those with compromised immune systems, and those with special needs are most vulnerable. The introduction of a disease such as the plague or influenza could rapidly impact those at risk. Critical Facilities at Risk
None of the health hazards discussed in this chapter would have significant impact on the critical facilities or infrastructure of the planning area. However, health care facilities (including long-term care and clinics and even veterinary offices) have adopted the recommended “all-hazards” approach to preparedness and have prepared for the health hazards addressed in this hazard profile. Climate Change Considerations There is no clearly identified link between climate change and influenza, although changes in animal migration patterns may create new opportunities for influenza mutation. The West Nile virus, however, is expected to be impacted by changing climate conditions. As climate change causes temperatures to rise, the time of year when mosquitoes are most active is expected to increase, resulting in greater opportunities for the spread of the disease. Summary Vulnerability/Risk Assessment As described above, Orange County as a whole, and thus the City of San Juan Capistrano, is vulnerable to influenza, West Nile virus, and to some extent the Zika virus. San Juan Capistrano does not have any unique conditions that make the community more or less vulnerable to the impacts of these diseases.
August 2019 95
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) Severe Weather General Background Severe weather refers to any dangerous meteorological phenomena with the potential to cause damage, serious social disruption, or loss of human life. It includes thunderstorms, downbursts, tornadoes, waterspouts, snowstorms, ice storms, and dust storms. Severe weather can be categorized into two groups: systems that form over wide geographic areas are classified as general severe weather; those with a more limited geographic area are classified as localized severe weather. Severe weather, technically, is not the same as extreme weather, which refers to unusual weather events at the extremes of the historical distribution for a given area. Definitions
Atmospheric River - A long, narrow region in the atmosphere that transports most of the water vapor outside of the tropics. These columns of vapor move with the weather, carrying large amounts of water vapor and strong winds. When atmospheric rivers make landfall, they release this vapor in the form of rain or snow, causing flooding and mudslide vents.
Extreme Heat - Temperatures that hover 10ºF or more above the average high temperature for a region and last for several weeks. Humid or muggy conditions occur when a “dome” of high atmospheric pressure traps hazy, damp air near the ground. Extremely dry and hot conditions can provoke dust storms and low visibility.
Severe Local Storm - Small atmospheric systems, including tornadoes, thunderstorms, windstorms, ice storms, and snowstorms. Typically, major impacts from a severe storm are on transportation, infrastructure, and utilities. These storms may cause a great deal of destruction and even death, but their impact is generally confined to a small area.
Thunderstorm - Any rain event that includes thunder and lightning. A typical thunderstorm is about 15 miles in diameter and lasts about 30 minutes.
Tornado - Tornadoes are funnel clouds of varying sizes that touch ground. Tornadoes are measured using the Enhanced Fujita Scale ranging from EF0 to EF6.
Santa Ana Winds-Warm, dry winds that blow from the east or northeast (offshore). These winds occur below the passes and canyons of the coastal ranges of Southern California and in the Los Angeles and Orange County basins. Santa Ana winds often blow with exceptional speed in the Santa Ana Canyon (the canyon from which it derives its name). Forecasters at the National Weather Service offices in Oxnard and San Diego usually place speed minimums on these winds and reserve the use of "Santa Ana" for winds greater than 25 knots. These winds accelerate to speeds of 35 knots as they move through canyons and passes, with gusts to 50 or even 60 knots.
August 2019 96
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) Heavy Rain, Atmospheric River, or Thunderstorm Most severe storms in the planning area consist of atmospheric rivers, heavy rains, or thunderstorms. Heavy rain refers to events where the amount of rain exceeds normal levels. The amount of precipitation needed to qualify as heavy rain varies with location and season. Heavy rain is distinct from climate change analyses on increasing precipitation. It does not mean that the total amount of precipitation at a location has increased, just that the rain is occurring in a more intense event. More frequent heavy rain events, however, can serve as indicators of changing precipitation levels. Heavy rain is most frequently measured by tracking the frequency of events, analyzing the mean return period, and measuring the amount of precipitation in a certain period (most typically inches of rain within a 24-hour period).
A relatively common weather pattern that brings southwest winds and heavy rain to California is often referred to as an atmospheric river. Atmospheric rivers are long, narrow regions in the atmosphere that transport most of the water vapor carried away from the tropics. These columns of vapor move with the weather, carrying large amounts of water vapor and strong winds. When the atmospheric rivers make landfall, they often release this water vapor in the form of rain or snow, causing flooding and mudslide vents.
The City of San Juan Capistrano is vulnerable to heavy rainfall, thunderstorm, and atmospheric river events as they make landfall in Southern Orange County. These events can drop up to 12 inches of rain over a few days and cause widespread flooding and disruption to road and air travel. Thunderstorms There are four types of thunderstorms:
Single-Cell Thunderstorms
Single-cell thunderstorms usually last from 20 to 30 minutes. A true single-cell storm is rare because the gust front of one cell often triggers the growth of another. Most single-cell storms are not usually severe, but a single-cell storm can produce a brief severe weather event. When this happens, it is called a pulse severe storm.
Multi-Cell Cluster Thunderstorm
A multi-cell cluster is the most common type of thunderstorm. The multi-cell cluster consists of a group of cells, moving as one unit, with each cell in a different phase of the thunderstorm life cycle. Mature cells are usually found at the center of the cluster and dissipating cells at the downwind edge. Multi-cell cluster storms can produce moderate-size hail, flash floods, and weak tornadoes. Each cell in a multi-cell cluster lasts only about 20 minutes; the multi-cell cluster itself may persist for several hours. This type of storm is usually more intense than a single cell storm.
Multi-Cell Squall Line
A multi-cell line storm, or squall line, consists of a long line of storms with a continuous well-developed gust front at the leading edge. The line of storms can be solid, or there can be
August 2019 97
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
gaps and breaks in the line. Squall lines can produce hail up to golf-ball size, heavy rainfall, and weak tornadoes, but they are best known as the producers of strong downdrafts. Occasionally, a strong downburst will accelerate a portion of the squall line ahead of the rest of the line. This produces what is called a bow echo. Bow echoes can develop with isolated cells as well as squall lines. Bow echoes are easily detected on radar but are difficult to observe visually.
Super-Cell Thunderstorm
A super-cell is a highly organized thunderstorm that poses a high threat to life and property. It is similar to a single-cell storm in that it has one main updraft, but the updraft is extremely strong, reaching speeds of 150 to 175 miles per hour. Super-cells are rare. The main characteristic that sets them apart from other thunderstorms is the presence of rotation. The rotating updraft of a super-cell (called a mesocyclone when visible on radar) helps the super- cell to produce extreme weather events, such as giant hail (more than 2 inches in diameter), strong downbursts of 80 miles an hour or more, and strong to violent tornadoes.
NOAA classifies a thunderstorm as a storm with lightning and thunder produced by cumulonimbus clouds, usually producing gusty winds, heavy rain, and sometimes hail. Thunderstorms are usually short in duration (seldom more than two hours). Heavy rains associated with thunderstorms can lead to flash flooding during the wet or dry season. According to the American Meteorological Society Glossary of Meteorology, thunderstorms are reported as light, medium, or heavy according to the following characteristics: Nature of the lightning and thunder Type and intensity of the precipitation, if any Speed and gustiness of the wind Appearance of the clouds Effect on surface temperature
Three factors cause thunderstorms to form: moisture, rising unstable air (air that keeps rising when disturbed), and a lifting mechanism to provide the disturbance. The sun heats the surface of the earth, which warms the air above it. If this warm surface air is forced to rise (hills or mountains can cause rising motion, as can the interaction of warm air and cold air or wet air and dry air), it will continue to rise as long as it weighs less and stays warmer than the air around it. As the air rises, it transfers heat from the surface of the earth to the upper levels of the atmosphere (the process of convection). The water vapor it contains begins to cool, and it condenses into a cloud.
The cloud eventually grows upward into areas where the temperature is below freezing. Some of the water vapor turns into ice, and some of it turns into water droplets. Both have electrical charges. Ice particles usually have positive charges, and rain droplets usually have negative charges. When the charges build up enough, they are discharged in a bolt of lightning, which causes the sound waves we hear as thunder.
August 2019 98
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Thunderstorms have three stages (see Figure 3.3)
1. The developing stage of a thunderstorm is marked by a cumulus cloud that is being pushed upward by a rising column of air (updraft). The cumulus cloud soon looks like a tower (called towering cumulus) as the updraft continues to develop. There is little to no rain during this stage but occasional lightning. The developing stage lasts about 10 minutes. 2. The thunderstorm enters the mature stage when the updraft continues to feed the storm, but precipitation begins to fall out of the storm, and a downdraft begins (a column of air pushing downward). When the downdraft and rain-cooled air spread out along the ground, they form a gust front, or a line of gusty winds. The mature stage is the most likely time for hail, heavy rain, frequent lightning, strong winds, and tornadoes. The storm occasionally has a black or dark green appearance. 3. Eventually, a large amount of precipitation is produced, and the updraft is overcome by the downdraft beginning the dissipating stage. At the ground, the gust front moves out a long distance from the storm and cuts off the warm moist air that was feeding the thunderstorm. Rainfall decreases in intensity, but lightning remains a danger.
Figure 3.3: Developing Stages of a Thunderstorm
A thunderstorm is a rain event that includes thunder and lightning. A thunderstorm is classified as “severe” when it produces one or more of the following:
Hail with a diameter of three-quarter inch or greater Winds gusting in excess of 50 knots (57.5 mph) Tornado(s)
August 2019 99
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Tornados Tornadoes are spawned when there is warm, moist air near the ground, cool air aloft, and winds that speed up and change direction. An obstruction, such as a house, in the path of the wind causes it to change direction. This change increases pressure on parts of the house, and the combination of increased pressures and fluctuating wind speeds creates stresses that frequently cause structural failures.
In order to measure the intensity and wind strength of a tornado, Dr. T. Theodore Fujita developed the Fujita Tornado Damage Scale. This scale compares the estimated wind velocity with the corresponding amount of suspected damage. The scale measures six classifications of tornadoes with increasing magnitude from a “F0” tornado to a “F6+” tornado, as depicted in Figure 3.4.
Figure 3.4: Fujita Scale and Enhanced Fujita Scale
Lightning Lightning is an electrical discharge that results from the buildup of positive and negative charges within a thunderstorm. When the buildup becomes strong enough, lightning appears as a “bolt”. This flash of light usually occurs within the clouds or between the clouds and the ground. A bolt of lightning reaches temperatures approaching 50,000ºF instantaneously. The rapid heating and cooling of air near the lightning causes thunder. Lightning is a major threat during a thunderstorm. In the United States, between 75 and 100 Americans are struck and killed by lightning each year. Hail Storms Hail occurs when updrafts in thunderstorms carry raindrops upward into extremely cold areas of the atmosphere where they freeze into ice. Recent studies suggest that super-cooled water may accumulate on frozen particles near the back-side of a storm as they are pushed forward, across, and above the updraft by the prevailing winds near the top of the storm. Eventually, the hailstones encounter downdraft air and fall to the ground.
August 2019 100
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Hailstones grow two ways: by wet growth or dry growth. In wet growth, a tiny piece of ice is in an area where the air temperature is below freezing but not super-cooled. When the tiny piece of ice collides with a super-cooled drop, the water does not freeze on the ice immediately. Instead, liquid water spreads across tumbling hailstones and slowly freezes. Since the process is slow, air bubbles can escape, resulting in a layer of clear ice. Dry growth hailstones grow when the air temperature is well below freezing, and the water droplet freezes immediately as it collides with the ice particle. The air bubbles are “frozen” in place, leaving cloudy ice.
Hailstones can have layers like an onion if they travel up and down in an updraft, or they can have few or no layers if they are “balanced” in an updraft. One can tell how many times a hailstone traveled to the top of the storm by counting its layers. Hailstones can begin to melt and then re-freeze together, forming large and very irregularly shaped hail. Extreme Heat Extreme heat poses substantial health risks to a number of people. Extreme heat events can override the body’s ability to maintain a safe internal temperature (an ability known as thermoregulation), potentially causing the body’s temperature to rise to dangerous levels. The symptoms of heat-related illnesses, such as heat stroke, may include headache, dizziness, rash, fainting, and seizures. If not treated, extreme heat can result in coma or death.
Figure 3.5: National Weather Service Heat Index50
50 National Weather Service, 2016
August 2019 101
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
The risks of extreme heat are greatest among elderly individuals, particularly those 85 years of age or older. Heat-related mortality rises sharply with age, and elderly people can suffer potentially fatal respiratory and cardiovascular conditions during high temperatures. Elderly individuals may also be less able to take care of themselves during extreme heat event, and may be more likely to take a medication that impacts their thermoregulatory capacity.
Extreme heat risks are high as well among lower-income individuals, who are more likely to live in housing with no or inadequate cooling capacity (e.g., an air conditioner); and they may not have access to effective transportation that can allow them to reach cooling centers or seek other assistance as needed. Outdoor workers, such as construction workers, are more exposed to extreme heat conditions than many other people and are therefore also at increased risk of extreme heat.
Other impacts of extreme heat can indirectly affect a person’s health. Power lines become less efficient during extreme heat events; coupled with increased stress on the electric grid due to increased energy demand for cooling, this can cause blackouts. During particularly intense heat events, roads and railways may be damaged by the high temperatures, resulting in transportation delays. Extreme heat events can cause an increase in the number of blackouts and other failings of the electrical power grid, driven by greater electrical demand for cooling and heat stress on the grid’s mechanical system. Power outages may in turn have impacts on other utility systems and key services. Damaging Winds Windstorms are generally short-duration events involving straight-line winds or gusts of over 50 mph, strong enough to cause property damage. Windstorms are especially dangerous in areas with significant tree stands and areas with exposed property, poorly constructed buildings, mobile homes (manufactured housing units), major infrastructure, and above-ground utility lines. A windstorm can topple trees and power lines, cause damage to residential, commercial, and critical facilities, and leave tons of debris in its wake.
Damaging winds are classified as those exceeding 60 mph. Damage from such winds account for half of all severe weather reports in the lower 48 states and is more common than damage from tornadoes. Wind speeds can reach up to 100 mph and can produce a damage path extending for hundreds of miles.
There are seven types of damaging winds: Straight-Line Winds - Any thunderstorm wind that is not associated with rotation; this term is used mainly to differentiate from tornado winds. Most thunderstorms produce some straight-line winds as a result of outflow generated by the thunderstorm downdraft. Downdrafts - A small-scale column of air that rapidly sinks toward the ground. Downbursts - A strong downdraft with horizontal dimensions larger than 2.5 miles resulting in an outward burst or damaging winds on or near the ground. Downburst winds may begin as a microburst and spread out over a wider area, sometimes producing damage similar to a strong tornado. Although usually associated with thunderstorms, downbursts can occur with showers too weak to produce thunder.
August 2019 102
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Microbursts - A small, concentrated downburst that produces an outward burst of damaging winds at the surface. Microbursts are generally less than 2.5 miles across and short-lived, lasting only 5 to 10 minutes, with maximum wind speeds up to 168 mph. There are two kinds of microbursts: wet and dry. A wet microburst is accompanied by heavy precipitation at the surface. Dry microbursts, common in places like the high plains and the intermountain west, occur with little or no precipitation reaching the ground. Gust Front - A gust front is the leading edge of rain-cooled air that clashes with warmer thunderstorm inflow. Gust fronts are characterized by a wind shift, temperature drop, and gusty winds out ahead of a thunderstorm. Sometimes the winds push up air above them, forming a shelf cloud or detached roll cloud. Derecho - A derecho is a widespread thunderstorm wind caused when new thunderstorms form along the leading edge of an outflow boundary (the boundary formed by horizontal spreading of thunderstorm cooled air). The word “derecho” is of Spanish origin and means “straight ahead”. Thunderstorms feed on the boundary and continue to reproduce. Derechos typically occur in summer when complexes of thunderstorms form over plains, producing heavy rain and severe wind. The damaging winds can last a long time and cover a large area. Bow Echo - A bow echo is a linear wind front bent outward in a bow shape. Damaging straight-line winds often occur near the center of a bow echo. Bow echoes can be 200 miles long, last for several hours, and produce extensive wind damage at the ground. Severe Weather Hazard Profile Community Severe Weather Issues The most common severe weather events that impact the planning area are heavy rains/atmospheric rivers/thunderstorms, extreme heat, and damaging winds. Flooding can be caused by severe weather and is discussed under its own heading later in this chapter. Based on the history of the region, windstorm events can be expected, perhaps annually, across widespread areas of the region. Obviously, the City and surrounding region can be adversely impacted during a windstorm event. This can result in the involvement of the City of San Juan Capistrano's emergency response personnel during a wide ranging windstorm or microburst tornado activity. Life and Property Both residential and commercial structures with weak reinforcement are susceptible to damage. Wind pressure can create a direct and frontal assault on a structure, pushing walls, doors, and windows inward. Conversely, passing currents can create lift suction forces that pull building components and surfaces outward. With extreme wind forces, the roof or entire building can fail, causing considerable damage. Debris carried along by extreme winds can directly contribute to loss of life and indirectly to the failure of protective building envelopes, siding, or walls. When severe weather strikes a community, downed trees, power lines, and damaged property can be major hindrances to emergency response and disaster recovery.
August 2019 103
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Utilities Historically, falling trees have been the major cause of power outages in the region. Windstorms such as strong microbursts and Santa Ana Wind conditions can cause flying debris and downed utility lines. For example, tree limbs breaking in winds of only 45 mph can be thrown over 75 feet. As such, overhead power lines can be damaged even in relatively minor windstorm events. Falling trees can bring electric power lines down to the pavement, creating the possibility of lethal electric shock. Rising population growth and new infrastructure in the region creates a higher probability for damage to occur from windstorms as more life and property are exposed to risk. Infrastructure Windstorms/severe weather can damage buildings, power lines, and other property and infrastructure due to falling trees and branches. During wet winters, saturated soils cause trees to become less stable and more vulnerable to uprooting from high winds. Windstorms/severe weather can result in collapsed or damaged buildings. It can block roads and bridges, damaged traffic signals, streetlights, and parks, and others City property. Roads blocked by fallen trees during a windstorm may have severe consequences to people who need access to emergency services. Emergency response operations can be complicated when roads are blocked or when power supplies are interrupted. Industry and commerce can suffer losses from interruptions in electric services and from extended road closures. They can also sustain direct losses to buildings, personnel, and other vital equipment. There are direct consequences to the local economy resulting from windstorms/severe weather related to both physical damages and interrupted services. Increased Fire Threat Perhaps the greatest danger from windstorm activity in Southern California comes from the combination of the Santa Ana winds with the major fires that occur every few years in the urban/wildland interface. With the Santa Ana winds driving the flames, the speed and reach of the flames is even greater than in times of calm wind conditions. The higher fire hazard raised by a Santa Ana wind condition requires that even more care and attention be paid to proper brush clearances on property in the wildland/urban interface areas. Transportation Windstorm activity can have an impact on local transportation in addition to the problems caused by downed trees and electrical wires blocking streets and highways. During periods of extremely strong Santa Ana winds, major highways can be temporarily closed to truck and recreational vehicle traffic. However, typically these disruptions are not long lasting, nor do they carry a severe long term economic impact on the region.
August 2019 104
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) Location and Extent of Severe Weather Hazard Thunderstorms
Thunderstorms affect relatively small localized areas, rather than large regions. It is estimated that there are as many as 40,000 thunderstorms each day worldwide. Thunderstorms can strike in all regions of the United States; however, they are most common in the central and southern states.
Map 3.8 shows the annual number of thunderstorms in the United States. According to this figure, the planning area can experience around five thunderstorms each year.
Map 3.8: Annual Number of Thunderstorms in the United States
August 2019 105
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) High Winds
The entire city is subject to high winds from thunderstorms and other severe weather events. San Juan Capistrano is located in FEMA’s Wind Zone I, where wind speeds can reach up to 130 mph.
Map 3.9 indicates how the frequency and strength of windstorms impacts the United States and the general location of the most wind activity.
Map 3.9: Wind Zones in the United States51
Extreme Heat
Extreme heat can occur anywhere in the planning area, and there is no clearly defined extent and location mapping data available for this hazard to support geospatial analysis. Extreme heat is a concern to people, animals, and pets as well as local nursery crops, cut flowers, and vegetable crops. However, it is rare that extreme heat events directly damage property or infrastructure.
51 USFS 2013
August 2019 106
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) Past Occurrences Tornados
Tornadoes are not common in San Juan Capistrano; however, the two strongest tornadoes recorded in California occurred five years and a few miles apart from one another. The first was recorded on August 16, 1973, near Blythe in the Colorado Desert. The tornado was extremely short-lived, was on the ground for a tenth of a mile, and was only ten yards wide. Meteorologists rated it an F3, and it produced between $5,000 and $50,000 in damage. The other major tornado occurred in Orange County on February 9, 1978 and was also rated an F3. It injured 6 people and produced more than half a million dollars in damage. Extreme Heat
The number of extreme heat events in the City of San Juan Capistrano varies from year to year. On average, the community experiences five extreme heat days and 0 to 2 heat waves per year. These events typically occur between the months of July through October and in rare occasions can occur in April, May, or June. According to the National Climatic Data Center, Orange County experiences 9-14 days of extreme heat per summer.52
Figure 3.6: Average Annual Temperatures in California vs. Historic Average53
NOTES: The figure shows annual average temperatures and the historical average for the period of 1931 to 2014, for a breakdown by summer and winter months.
52 National Resources Defense Council, www.nrdc.org/climate-change-and-health-extreme-heat#/map/detail/CA. (Accessed 2/11/2019) 53 National Oceanic and Atmospheric Administration
August 2019 107
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
A historic heat wave obliterated records across southern California on July 6, 2018. Many locations recorded temperatures 10° to 15°F higher than the previous daily record. Monthly and all-time heat records were also set in many locations. Record breaking heat waves are a classic signal of climate change.
On July 6, the hottest all-time temperature on record occurred at UCLA (111°F), Burbank Airport (114°F), Van Nuys Airport (117°F), Ramona (117°F), Santa Ana (114°F), and Riverside (118°F, tying the record from 1925) 82°F: Hottest all-time overnight low temperature on record for any month in Burbank, California 79°F: Hottest overnight low temperature on record for the month of July in Los Angeles on July 7 120° F: Highest temperature (set in Chino on July 6) ever recorded by any automated weather station in the valleys or coastal areas around Orange, Riverside, San Bernardino, and San Diego Counties54
This heat wave occurred less than one year after California experienced its all-time greatest statewide heat wave. The past year has witnessed a global wave of record-breaking extreme heat including the highest overnight temperature ever recorded. Damaging Wind
In 2003, two deaths were blamed on strong winds: a downed tree struck and killed a woman in San Diego, and a passenger in a vehicle was struck by a flying pickup truck cover (http://cbsnew.com/ January 8, 2003 article). Several major wildland fires have occurred in Orange County during Santa Ana wind conditions, when the air humidity is low to very low. Because the winds fan and help spread these fires, Santa Ana wind conditions are always serious concerns.
Table 3.11 identifies past windstorms and Santa Ana events in Southern California from 1957 through May of 2017. Of these events, the windstorms in 1987, 1988, 1997, 1998, 2000, 2007, 2008, 2010, 2014, and 2016 directly impacted Orange County.
Table 3.11: Major Windstorms/Santa Ana Events in Orange County55 Dates Location/Event Damage Winds produced a 28,000-acre brush fire on a 40-mile front west of Crystal Lake. People were ordered off the streets in some areas due to flying debris. 12 of 33 November 21-22, Extremely destructive Santa Ana passengers on an airplane over Ontario 1957 winds. were hurt by a downdraft in extreme turbulence. Paint was completely stripped off of windward sides of 4 cars stalled in a Fontana sandstorm.
54 weather.com/forecast/regional/news/2018-07-03-southern-california-record-heat-southwest-monsoon-moisture (Accessed February 11, 2019) 55 National Weather Service. “A History of Significant Weather Events in Southern California Organized by Weather Type. May 2017.
August 2019 108
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Dates Location/Event Damage
Fire in Topanga Canyon. 103 injured Strong Santa Ana winds fanned fires firemen, $100 million economic losses November 5-6, 1961 in Bel Air and Brentwood. including 484 buildings (mostly residential) and 6,090 acres destroyed.
January 18-28, 1969 Strong storm winds. 4 dead from falling trees. Power outages. Strong storm winds caused damage to February 10-11, 1973 Strong storm winds. trees and some flying debris. Wind gust of 101 mph at the community of Sandberg (located in N. March 25, 1975 None reported. Los Angeles County), a California record. Hurricane Kathleen brought the southwest the highest sustained September 10, 1976 winds ever associated with an None reported. Eastern Pacific tropical cyclone with sustained winds of 57 mph at Yuma.
A major wildfire moved across the Santa October 9, 1982 Santa Ana winds gusted to 60 mph. Monica Mountains.
Strong Pacific storm brought gale December 4-5, 1987 force winds along the coast Trees down. Power outages. exceeding 40 mph in many areas.
Strong storm winds of 100 mph at Wheeler Ridge in the Tehachapi Mountains. 80 mph in San Bernardino December 15, 1987 County. Up to 70 mph gusts at Point One truck overturned. Arguello and gusts up to 60 mph were clocked in Orange County and the San Gabriel Mountains.
Numerous trees and power lines downed, and power outages all near the foothills of the San Gabriel and San Bernardino Mountains. Three were killed when a big rig truck overturned and burned; one was Very strong Santa Ana winds: Gusts killed having stepped on a downed power of 90 mph at Newport Beach, 70+ line. Power outages hit 200,000 February 16-19, 1988 mph in the San Gabriel Mountain customers in LA and Orange Counties. foothills. Minor structural damage occurred to signs, etc. Grass fires resulted. Roof damage was widespread in communities around Glendale and Pasadena. Planes flipped in Burbank and at John Wayne airports.
August 2019 109
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Dates Location/Event Damage
The Old Topanga fire burned from Santa Ana winds gusted to over 60 November 2-4, 1993 Calabasas to the ocean, consuming mph. hundreds of homes and other structures.
The remnants of Tropical Storm Ignacio tracked northward moving inland in central California with gale August 20, 1997-98 force winds over portions of the None reported. Southern California coastal waters. This occurred during the strong El Niño of 1997-98.
One of the most severe windstorms in Southern California history. Caused the closure of the Foothill Freeway; damage to vehicles, sidewalks, irrigation systems, and public buildings. Over 50 trees were January 6-7, 1997 Severe windstorm. lost; local streets were closed to traffic shortly after the windstorm due to leaning power poles and downed electrical lines. It was estimated at the time that the windstorm caused $310,000 in damage.
Santa Ana winds: gusts 87 mph in October 14, 1997 Large fire in Orange County. central Orange County.
Strong storm winds: gusts 60 mph at February 3-4, 1998 None reported. Newport Harbor, 51 in San Clemente. Strong storm winds in Orange County: sustained 30-40 mph. Gust Trees down, power out, and damage March 28-29, 1998 70 mph at Newport Beach, gusts 60 across Orange and San Diego County. mph at Huntington Beach. Gusts to 1 dead in Jamul. 60 mph in the mountains.
Santa Ana winds: gust 93 mph at April 1, 2000 Mission Viejo, 67 mph at Anaheim None reported. Hills.
Very strong Santa Ana winds. Gusts recorded at Fremont Canyon (85 Winds caused at least $60 million in mph); San Bernardino (79 mph); damage and destruction to buildings, Descanso and Mira Loma (75 mph); fences, vehicles, etc. The devastating October 21-23, 2007 and Fallbrook and Rancho wildfires of 2007 were fanned by these Cucamonga (74 mph). Some winds. These fires caused the largest locations experienced tropical storm mass evacuation in California history. force winds (or greater) for 36+ consecutive hours.
Santa Ana winds gusted over 70 mph Freeway Complex Fire from Corona November 15, 2008 in the Santa Ana mountains and over through Chino Hills and Yorba Linda 60 mph in the northern Inland Empire. burned more than 30,000 acres.
August 2019 110
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Dates Location/Event Damage Winds downed trees and power lines, Santa Ana wind gusts of up to 83 mph January 9, 2009 overturned semi-trucks, and damaged at Fremont Canyon. roofs.
The high winds resulted in downed power lines and minor roof damage. A 50 acre brush fire in Palm Springs damaged two Strong onshore winds produced a homes and led to the evacuation of 50 April 3, 2009 gust of over 70 mph in Lucerne other homes. The fire began in the late Valley. afternoon, burning desert scrub near a residential neighborhood, and was contained later that evening.
Several waterspouts and very strong winds of 93 mph were also reported in Newport Beach and Huntington Beach. A Strong storm winds struck the region. tornado occurred in Seal Beach and January 19, 2010 Wind gusts reached 60 mph in San Huntington Beach. A tree fell onto a Clemente. mobile home in Lakeside, causing one fatality. Local damage including boats in Huntington Harbor.
Offshore winds: gusts to 82 mph at Fremont Canyon, 74 mph in Crestline, Trees and power lines down. Overturned January 7, 2012 66 mph at Santiago Peak, 60 mph at big rigs. Ontario.
A strong storm hit Southern California Numerous large trees and power poles with westerly winds. A report of a 102 toppled, as well as damage at John February 28- mph wind gust came from the Bear Wayne Airport. Thunderstorms on 2/28 March 1, 2014 Mountain ski resort weather downed several trees and damaged equipment on 2/28/14. power lines.
The strongest and most widespread offshore wind event in years occurred Numerous trees and power lines were very late in the season. Gusts downed in the San Diego County interior. May 1, 2014 reached as high as 100 mph at Sill A Garden Grove school incurred roof Hill near Cuyamaca Peak. Numerous damage. The Etiwanda fire near Rancho other stations measured speeds that Cucamonga broke out. exceeded 60 mph.
The winds knocked down many trees and power lines, and blew off some roof tiles. A strong late-season Santa Ana wind Numerous fires erupted especially in San event raked the region. Winds gusted Diego County, burning over 27,000 acres May 12, 2014 to 40 to 45 mph in parts of the coast and causing more than $50 million in and valleys and 60 to 80 mph in the property damage. The Poinsettia fire in foothills. Carlsbad and the Cocos Fire in San Marcos damaged homes, but no serious injuries or deaths resulted.
August 2019 111
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Dates Location/Event Damage A powerful storm with a surface low that rapidly deepened in the Southern California Bight brought an Over 500 downed trees caused extensive exceptionally strong cold front with damage. One woman was killed, and two January 31, 2016 widespread damaging wind gusts of were injured when a pine tree eight feet in 40-70 mph from the coast to the diameter crushed four cars in Pacific mountains. A broken line of Beach. thunderstorms formed along the front and combined with post frontal winds.
Probability of Future Occurrence Predicting the frequency of severe weather events in a constantly changing climate is a difficult task. The planning area can expect to experience exposure to and adverse impacts from some type of severe weather event at least annually. The prevalence of annual Santa Ana winds in the region creates a high probability of future occurrences of windstorms throughout Southern California. It is difficult to predict the amount of damage that could occur from a windstorm with great precision. Based on current modeling and information, it is anticipated that most windstorms will follow the general patterns that have historically affected both the city and the region. Climate Change Considerations Record breaking temperatures are a classic signal of climate change. As the average global temperature rises and the climate shifts, hot temperatures that were extreme under the old climate are closer to the middle of the new temperature range.56 Under the earth's climate system, events closer to the midpoint of the climate range occur much more frequently than events closer to the extremes, as shown in the graphic below. The shifting bell curve also leads to the occurrence of never-before-seen extremes in high temperatures.57
Graph 3.1: Increase in Average Temperatures
56 James Hansen, Makiko Sato, Reto Ruedy. Proceedings of the National Academy of Sciences “Perception of climate change” 57 Recent Trends in Northern and Southern Hemispheric Cold and Warm Pockets, Richard Grumm and Anne Balogh, National Weather Service and Penn State University
August 2019 112
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Extreme heat is one of the primary risks posed by climate change in California. As a result of increased temperatures and other changes to climate conditions, the number of extreme heat days in San Juan Capistrano is expected to increase from the current average of two each year to 11 annually by 2050.58 Summary Vulnerability/Risk Assessment Although severe local storms are infrequent, impacts can be significant, particularly when secondary hazards of flood and landslide occur. A worst-case event would involve prolonged high winds during a winter storm accompanied by an atmospheric river event. Such an event would have both short-term and longer-term effects.
Initially, schools and roads would be closed due to power outages caused by high winds and downed tree obstructions. Prolonged rain could produce flooding, overtopped culverts with flooding on streets, mud over roadways, and landslides on steep slopes.
Like other communities in the region, Orange County is at an elevated risk of extreme heat. Urbanized areas experience higher temperatures than rural communities (known as the urban heat island effect), which could further elevate temperatures in and around San Juan Capistrano.
58 https://cal-adapt.org/tools/extreme-heat, (2/11/19)
August 2019 113
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) Flood General Background A floodplain is the area adjacent to a river, creek, or lake that becomes inundated during a flood. Floodplains may be broad, as when a river crosses an extensive flat landscape, or narrow, as when a river is confined in a canyon.
When floodwaters recede after a flood event, they leave behind layers of rock and mud. These gradually build up to create a new floor of the floodplain. Floodplains generally contain unconsolidated sediments (accumulations of sand, gravel, loam, silt, and/or clay), often extending below the bed of the stream. These sediments provide a natural filtering system, with water percolating back into the ground and replenishing groundwater. These are often important aquifers, the water drawn from them being filtered compared to the water in the stream. Fertile, flat, reclaimed floodplain lands are commonly used for agriculture, commerce, and residential development.
Connections between a river and its floodplain are most apparent during and after major flood events. These areas form a complex physical and biological system that not only supports a variety of natural resources but also provides natural flood and erosion control. When a river is separated from its floodplain with levees and other flood control facilities, natural, built-in benefits can be lost, altered, or significantly reduced. Definition
Flooding occurs when climate, geology, and hydrology combine to create conditions where water flows outside of its usual course. In the City of San Juan Capistrano, geography and climate may combine to create seasonal flooding conditions. Flood hazard includes riverine (inland) flooding, coastal flooding, and storm-water flooding. Flooding caused by dam failure and tsunamis are also discussed under this hazard profile.
Floodplain - A floodplain is a land area adjacent to a river, stream, lake, estuary, or other water body that is subject to flooding. This area, if left undisturbed, acts to store excess flood water. The floodplain is made up of two sections: the floodway and the flood fringe.
100-Year Flood - The 100-year flooding event is the flood having a one percent chance of being equaled or exceeded in magnitude in any given year. Contrary to popular belief, it is not a flood occurring once every 100 years. The 100-year floodplain is the area adjoining a river, stream, or watercourse covered by water in the event of a 100-year flood.
Floodway - The City of San Juan Capistrano regulations prohibit all development in the floodway. The floodway is one of two main sections that make up the floodplain. Floodways are
August 2019 114
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
defined for regulatory purposes. Unlike floodplains, floodways do not reflect a recognizable geologic feature. For National Flood Insurance Program (NFIP) purposes, floodways are defined as the channel of a river or stream, and the overbank areas adjacent to the channel. The floodway carries the bulk of the flood water downstream and is usually the area where water velocities and forces are the greatest. NFIP regulations require that the floodway be kept open and free from development or other structures that would obstruct or divert flood flows onto other properties.
Flood Fringe - The flood fringe refers to the outer portions of the floodplain, beginning at the edge of the floodway and continuing outward. Generally, the flood fringe is defined as "the land area, which is outside of the stream floodway, but is subject to periodic inundation by regular flooding". This is the area where development is most likely to occur and where precautions to protect life and property need to be taken.
Development - For floodplain ordinance purposes, development is broadly defined by the City of San Juan Capistrano Municipal Code to mean "any manmade change to improve, including but not limited to buildings or other structures, mining, dredging, filling, grading, paving, excavation, or drilling operations". The definition of development for floodplain purposes is generally broader and includes more activities than the definition of development used in other sections of local and use ordinances.
Base Flood Elevation (BFE) - The term "Base Flood Elevation" refers to the elevation (normally measured in feet above sea level) that the base flood is expected to reach. Base flood elevations can be set at levels other than the 100-year flood. Some communities choose to use higher frequency flood events as their base flood elevation for certain activities while using lower frequency events for others. For example, for the purpose of storm water management, a 25-year flood event might serve as the base flood elevation while the 500-year flood event may serve as base flood elevation for the tie down of mobile homes. The regulations of the NFIP focus on development in the 100-year floodplain. How Flood-Prone Areas Are Identified Flood maps and Flood Insurance Studies (FIS) are often used to identify flood-prone areas. The National Flood Insurance Program (NFIP) was established in 1968 as a means of providing low-cost flood insurance to the nation's flood-prone communities. The NFIP also reduces flood losses through regulations that focus on building codes and sound floodplain management. In the City of San Juan Capistrano, the NFIP and related building code regulations went into effect on March 1, 1978. NFIP regulations (44 Code of Federal Regulations (CFR) Chapter 1, Section 60.3) require that all new construction in floodplains must be elevated at or above base flood level. Geography and Geology of San Juan Capistrano The San Juan Capistrano area is the product of rainstorms and erosion. Most of the mountains that ring the valleys and coastal plain are deeply fractured faults and, as they (the mountains) grew taller, their brittle slopes were continually eroded. Rivers and streams carried boulders, rocks, gravel, sand, and silt down these slopes to the valleys and coastal plains. In places, these sediments are as much as twenty thousand feet thick. Much of the coastal plain rests on the ancient rock debris and sediment washed down from the mountains. This sediment can act as a sponge, absorbing vast quantities of
August 2019 115
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
rain in those years when heavy rains follow a dry period. But like a sponge that is near saturation, the same soil fills up rapidly when heavy rains follow a period of relatively wet weather. So even in some years of heavy rain, flooding is minimal because the ground is relatively dry. The same amount of rain following a wet period of time can cause extensive flooding.
Development in San Juan Capistrano has reduced the amount of open land left to absorb rainfall. This lack of open ground forces water to remain on the surface and rapidly accumulate. If it were not for the massive flood control system with its concrete lined river and stream beds, flooding would be a much more common occurrence, and the tendency is towards even less and less open land. In-fill building is becoming a much more common practice in many areas. Developers tear down an older home, which typically covers up to 40% of the lot size, and replace it with three or four town homes or apartments, which may cover 90-95% of the lot.
Another potential source of flooding is "asphalt creep”. The street space between the curbs of a street is a part of the flood control system. Water leaves property and accumulates in the streets, where it is directed towards the underground portion of the flood control system. The carrying capacity of the street is determined by the width of the street and the height of the curbs along the street. Often, when streets are being resurfaced, a one to two inch layer of asphalt is laid down over the existing asphalt. This added layer of asphalt subtracts from the rated capacity of the street to carry water. Thus, the original engineered capacity of the entire storm drain system is marginally reduced over time. Subsequent re-paving will further reduce the engineered capacity even more. The Effect of Development on Floods When structures or fill are placed in the floodway or floodplain, water is displaced. Development raises the river levels by forcing the river to compensate for the flow space obstructed by the inserted structures and/or fill. When structures or materials are added to the floodway or floodplain and no fill is removed to compensate, serious problems can arise. Flood waters may be forced away from historic floodplain areas.
As a result, other existing floodplain areas may experience flood waters that rise above historic levels. Local governments must require engineer certification to ensure that proposed developments will not adversely affect the flood carrying capacity of the Special Flood Hazard Area. Displacement of only a few inches of water can mean the difference between no structural damage occurring in a given flood event and the inundation of many homes, businesses, and other facilities. Careful attention should be given to development that occurs within the floodway to ensure that structures are prepared to withstand base flood events.
In highly urbanized areas, increased paving can lead to an increase in volume and velocity of runoff after a rainfall event, exacerbating the potential flood hazards. Care should be taken in the development and implementation of storm water management systems to ensure that these runoff waters are dealt with effectively.
August 2019 116
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) Flooding Hazard Profile Community Flooding Issues Riverine Flooding Riverine flooding is the overbank flooding of rivers and streams. The natural processes of riverine flooding add sediment and nutrients to fertile floodplain areas. Flooding in large river systems typically results from large-scale weather systems that generate prolonged rainfall over a wide geographic area, causing flooding in hundreds of smaller streams, which then drain into the major rivers. Shallow area flooding is a special type of riverine flooding. FEMA defines shallow flood hazards as areas that are inundated by the 100-year flood with flood depths of only one to three feet. These areas are generally flooded by low velocity sheet flows of water. Urban Flooding As land is converted from fields or woodlands to roads and parking lots, it loses its ability to absorb rainfall. Urbanization of a watershed changes the hydrologic systems of the basin. Heavy rainfall collects and flows faster on impervious concrete and asphalt surfaces. The water moves from the clouds, to the ground, and into streams at a much faster rate in urban areas. Adding these elements to the hydrological systems can result in flood waters that rise very rapidly and peak with violent force.
Over 50 percent of the area in the City of San Juan Capistrano has a high concentration of impermeable surfaces that either collect water or concentrate the flow of water in unnatural channels. During periods of urban flooding, streets can become swift moving rivers, and basements can fill with water. Storm drains often back up with vegetative debris causing additional, localized flooding. Monsoons Another relatively regular source for heavy rainfall, particularly in the mountains and adjoining cities, is from summer tropical storms. Table 3.12 lists tropical storms that have had significant rainfall in the past century and the general areas affected by these storms. These tropical storms usually coincide with EI Niño years.
Table 3.12: Historic Tropical Storms that Affected Southern California59 Month-Year Date(s) Source of Rain; Southern California Rainfall The only known historical hurricane that made a landfall in Southern California; 75- mph winds Oct. 1858 2nd & 3rd estimated in San Diego; tropical storm winds along > 7" coastline north to Long Beach; intense rain reported from San Diego to Santa Barbara. July 1902 20th & 21st Deserts and southern mountains. El Niño of 1901-02. up to 2"
59 http://www.nhc.noaa.gov; Chenoweth and Landsea, 2004 (on the 1858 Hurricane);
August 2019 117
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Month-Year Date(s) Source of Rain; Southern California Rainfall
Aug. 1906 18th & 19th Deserts and southern mountains. El Niño of 1905-06. up to 5" Sept. 1910 15th Mountains of Santa Barbara County. 2"
th Deserts of Southern California, and into Riverside. El Aug. 1915 26 1” Niño of 1914-15. Aug. 1921 20th & 21st Deserts and southern mountains. La Niña of 1920-21. up to 2" Sept. 1921 30th Deserts. La Niña of 1920-21. up to 4" Sept. 1929 18th Southern mountains and deserts. up to 4"
th st Mountains and deserts, 15 fatalities in the Tehachapi Sept. 1932 28 -Oct 1 up to 7” area. El Niño of 1932-33. Aug. 1935 25th Southern valleys, mountains and deserts. up to 2"
th Locally heavy rainfall in the mountains surrounding Aug. 1936 9 n/a Los Angeles.
th th Remnants of a hurricane; impacted the southern 4 -7 up to 7” mountains, and the southern and eastern deserts. Sept. 1939 (during El Niño 11th & 12th Deserts, central, and southern mountains. up to 4" of 1938-39) 19th- 21st Deserts, central, and southern mountains. up to 3"
Tropical cyclone that made a landfall in San Pedro, with sustained winds of 50 mph. Only known tropical cyclone to make a landfall in Southern 5" in LA Sept. 1939 th California. 93 people died; 45 onshore and 48 basin (during El Niño 25 offshore, at sea. Ten houses washed away in Belmont of 1938-39) Shores.
Surrounding mountains. 6 to 12"
Sept. 1945 9th & 10th Central and southern mountains. up to 2”
Sept. 1946 30th-Oct 1st Southern mountains. El Niño of 1946-47. up to 4"
th th Southern mountains and deserts; many roads washed Aug. 1951 27 -29 2 to 5" out in the Imperial Valley. El Niño of 1951-52.
th st Central and southern mountains. El Niño of Sept. 1952 19 -21 up to 2" 1951-52.
th Deserts and southern mountains. El Niño of July 1954 17 -19th up to 2" 1953-54.
th th Deserts and southern mountains. El Niño of July 1958 28 & 29 up to 2" 1957-58.
Sept. 1959 11th Spotty rainfall in the deserts and mountains. up to ½”
August 2019 118
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Month-Year Date(s) Source of Rain; Southern California Rainfall Hurricane Estelle dissipated west of Central Sept. 1960 9th & 10th Baja California; southern mountains at and near 3.40" Julian. Tropical storm Katherine made landfall in Sept. 1963 17th-19th northern Baja California; impacted central and up to 7" southern mountains. El Niño of 1963-64.
st rd Hurricane Katrina in Baja California; impacted Sept. 1967 1 -3 2" southern mountains and deserts. Caribbean-Sea Hurricane Irene crossed Nicaragua; Sept. – Oct. th st reformed in the eastern Pacific as Hurricane Olivia, 30 -Oct. 1 up to 1” 1971 which made landfall in Central Baja California; impacted southeast deserts. La Niña of 1970-71. Remnants of Hurricane Hyacinth made landfall rd between Los Angeles and San Diego with 25-mph Sept. 1972 3 up to 1” winds and rainfall in the central and southern mountains. El Niño of 1972- 1973. Hurricane Joanne made landfall in northern Baja;
Oct. 1972 th maintained tropical storm strength into Arizona; rain in 6 up to 2" southeast deserts. El Niño of 1972-1973. As a result of the tropical storm Kathleen; impacted the central and southern mountains; sustained winds Sept. 1976 of 57 mph at Yuma. Killed 12 people in the U.S.; 70- 6 to 12" 10th & 11th 80% of Ocotillo was destroyed; caused millions of dollars in damage. El Niño of 1976-1977. Hurricane Doreen dissipated over the Southern
California coastal waters. Widespread flooding; Aug. 1977 2" extensive crop damage. In Los Angeles and south, up n/a to 2” of rain.
1977-1988 n/a Mountains. El Niño of 1977-78. up to 8"
th th Remnants of Hurricane Heather tracked into Southern Oct. 1977 6 & 7 up to 2” Arizona; impacted southern mountains and deserts.
th th Remnants of Hurricane Norman impacted the Sept. 1978 5 & 6 > 3" mountains. El Niño of 1977-78.
th th Remnants of Hurricane Celia; scattered rainfall in June 1980 29 & 30 up to ½” Santa Barbara. Remnants of Hurricane Norman; with scattered rainfall Sept. 1982 17th & 18th in the southern mountains and deserts. Strong El Niño up to 1” of 1982-83.
th th Remnants of Hurricane Olivia; impacted the Sept. 1982 24 -26 up to 4" mountains. Strong El Niño of 1982-83. Hurricane Manuel dissipated off west coast of northern Sept. 1983 20th & 21st Baja California; impacted the southern mountains and up to 3" deserts. Strong El Niño of 1982-83.
th Remnants of Hurricane Priscilla scattered light rain Oct. 1983 7 n/a across Southern California. Strong El Niño of 1982-83. Hurricane Marie dissipated off the west coast Sept. 1984 10th & 11th of northern Baja California; scattered rain in coastal n/a areas.
August 2019 119
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Month-Year Date(s) Source of Rain; Southern California Rainfall Tropical storm Ignacio dissipated near the south- Aug. 1997 17th-19th central California coast with gale-force winds over n/a coastal waters. Strong El Niño of 1997-1998. Hurricane Linda, the strongest storm recorded in the eastern Pacific with 180-mph winds, threatened to come ashore in California as a subtropical storm. Sept. 1997 n/a n/a Storm turned away, but caused high surf, waves 18 ft. high, showers and thunderstorms. Strong El Niño of 1997-1998. Hurricane Nora crossed into Southern California and Arizona from Baja California. Brought heavy rain to Sept. 1997 25th n/a parts of the region, causing millions of dollars in damage to agriculture.
th th Mid-level moisture from hurricane Javier spread over Sept. 2004 10 -19 n/a northern Mexico, and southwestern US. Remnants of tropical storm Emilia brought rain to July 2006 31st Southern California that helped extinguish the House n/a Fire. Thunderstorms and showers; flooding watch in Santa Sept. 2007 20th-22nd Catalina Island; rain throughout the Southern n/a California area.
th th Remnants of Hurricane Fabio generated scattered July 2012 18 -20 n/a showers and thunderstorms in the Los Angeles basin. Moisture from the remnants of tropical storm Ivo caused flash floods and mudslides in San Bernardino Aug. 2013 25th–26th 3-4” County and Arizona. One motorist drowned in Needles.
Coastal Flooding Low lying coastal communities of Southern California have one other source of flooding, coastal flooding. This occurs most often during storms which bring higher than normal tides. Storms, the time of year, and the tidal cycle can sometimes work to bring much higher than normal tides, which cause flooding in low lying coastal areas. This hazard however is limited to those areas. Debris Flows Another flood related hazard that can affect certain parts of the Southern California region are debris flows. Most typically, debris flows occur in mountain canyons and the foothills. However, any hilly or mountainous area with intense rainfall and the proper geologic conditions may experience one of these very sudden and devastating events.
Debris flows, sometimes referred to as mudslides, mudflows, lahars, or debris avalanches, are common types of fast-moving landslides. These flows generally occur during periods of intense rainfall or rapid snow melt. They usually start on steep hillsides as shallow landslides that liquefy and accelerate to speeds that are typically about 10 miles per hour but can exceed 35 miles per hour. The consistency of debris flows ranges from watery mud to thick, rocky mud that can carry large items such as boulders, trees, and cars. Debris flows from many different sources can
August 2019 120
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
combine in channels, and their destructive power may be greatly increased. They continue flowing down hills and through channels, growing in volume with the addition of water, sand, mud, boulders, trees, and other materials. When the flows reach flatter ground, the debris spreads over a broad area, sometimes accumulating in thick deposits that can wreak havoc in developed areas.
Storm events are likely to generate debris flows in the upper reaches of the watershed. Debris laden water may move at relatively slow speeds of 3 to 5 miles per hour, but it can cause much damage along its way. Debris flows often occur in areas recently burned by wildfires, where vegetation has not yet formed a protective ground cover that helps keep the soil in place. Furthermore, the oils in the plants native to Southern California, when burned, react with the soils, making them water repellant. As a result, less rainwater than usual infiltrates the ground and instead, makes its way down-slope as runoff, carrying ashes and other burned debris with it. Based on data obtained from the U.S. Army Corps of Engineers, heavy flooding impacted the City many times over the years. Bridges were washed out, land was eroded, and crops were destroyed. Dam Failure Flooding Loss of life and damage to structures, roads, and utilities may result from a dam failure. Economic losses can also result from a lowered tax base and lack of utility profits. These effects would certainly accompany the failure of one of the major dams above the City of San Juan Capistrano. There are no dams in San Juan Capistrano; however, the City is located in the inundation path of three dams. Because dam failure can have severe consequences, FEMA requires that all dam owners develop Emergency Action Plans (EAP) for warning, evacuation, and post-flood actions.
Dam Failures in California
There have been a total of 45 dam failures in California, since the 19th century.
Table 3.13: Selected Dam Failures in California Name Location Year Description
Sheffield Santa Barbara 1925 Earthquake slide
Puddingstone Pomona 1926 Overtopping during construction
Lake Hemet Riverside County 1927 Overtopping Sudden failure at full capacity through Saint Francisquito Los Angeles 1928 foundation, 426 deaths Cogswell Monrovia 1934 Breaching of concrete cover Leak through embankment turned Baldwin Hills Los Angeles 1963 into washout, 3 deaths Main and emergency spillways were damaged, prompting the evacuation Oroville Dam Butte County 2017 of more than 180,000 people living downstream along the Feather River
August 2019 121
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Dams Surrounding San Juan Capistrano
The three dams that might impact the City of San Juan Capistrano in the event of a dam failure are Trampas Canyon Dam, Lake Mission Viejo Dam, and Upper Oso Reservoir. None of these dams are located in the City of San Juan Capistrano but due to their proximity to the City, might result in loss of life, damage to property and other ensuing hazards, as well as the displacement of persons residing in the inundation path. The inundation studies for the three dams are based on the worst-case scenarios. Map 3.10 illustrates the locations of the dams surrounding San Juan Capistrano.
August 2019 122 City of San Juan Capistrano Local Hazard Mitigation Plan Map 3.10: Dams Surrounding San Juan Capistrano
August 2019 123 City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Location and Extent of Flooding Hazard Streams, Rivers, and Creeks
There are four creeks that run through San Juan Capistrano that are part of a system for flood control for a large portion of Southern Orange County as depicted in Table 3.14 and Map 3.11.
Table 3.14: Streams, Rivers, and Creeks in San Juan Capistrano Name Length & Path 22 miles. Flows west and southwest before intersecting with Oso Creek in the Arroyo Trabuco, northwest corner of the City. From there it continues south and merges with San Juan aka, Trabuco Creek Creek before emptying into the ocean at Dana Point. 29 miles. Flows west and south through San Juan Canyon and is joined by Trabuco San Juan Creek Creek as it passes through San Juan Capistrano. It flows into the Pacific Ocean at Doheny State Beach. 13.5 miles. Flows from Lake Mission Viejo through parts of Laguna Hills and Laguna Oso Creek Niguel before meeting Trabuco Creek in the north/west corner of the City. 5.9 miles. Drains an area of 4.3 square miles. This creek joins San Juan Creek on the Horno Creek right bank, only a few hundred yards upstream of the Trabuco Creek confluence.
Map 3.11: Streams, Rivers, and Creeks in San Juan Capistrano
August 2019 124 City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) Potential for Inundation Due to Dam Failure Although there may be coordination with county officials in the development of the Emergency Action Plan (EAP), the responsibility for developing potential flood inundation maps and facilitation of emergency response is the responsibility of the dam owner.
Trampas Canyon Dam - serves as a settling basin for fine silts and clays as part of a sand processing operation. It is owned and operated by Oglebay Norton Industrial Sands, Inc. and was completed in 1975. It is located approximately 5 miles east of the 1-5 off Ortega Hwy within a tributary of San Juan Creek. The 1.9 million cubic yard earthen dam is approximately 1,300 feet long, 185 feet high, and has a storage capacity of approximately 220 million cubic feet (5,000 acre feet). The water depth varies from 0 feet to approximately 40 feet.
Areas of Inundation: Should a breach in the dam occur, the water released would spill into Trampas Creek. In the worst possible scenario, the debris embankment in Trampas Creek would probably be washed out. A mixture of mud, silt, and slurry wastes would flow into San Juan Creek and eventually continue south into the Pacific Ocean at Doheny State Beach in the City of Dana Point. Virtually all aquatic life in the affected creeks would be destroyed, as would much stream side vegetation. The material released from behind the dam would most likely overflow the Trampas Creek channel and perhaps the banks of San Juan Creek.
Areas that might require Evacuation: Property along San Juan Creek towards the Pacific Ocean.
Lake Mission Viejo Dam - is a recreational lake for the use of the residents of Mission Viejo. It is owned and operated by Lake Mission Viejo Management and Board of Directors. It is impounded by an earth filled structure that was completed in 1978. It is located in the northeast section of Mission Viejo and is surrounded by residential developments. The northern boundary is Olympiad Road and the southern is Alicia Parkway. The total area of the lake is 124 acres with a storage capacity of 4,300 acre feet. The average depth is 30' (greatest depth being 70').
Areas of Inundation: Water released would start at the south dam face and follow Oso Creek to and under Interstate 5 and then continue to flow south and merge with Trabuco Creek. From Trabuco Creek, it would merge with San Juan Creek and eventually flow south into the ocean at Doheny State Beach in the City of Dana Point. Depths at peak flow may reach up to 40’. The flood wave would reach the northern boundary of the City of San Juan Capistrano at approximately 0 + 1 hour, 20 minutes, and Doheny State Beach at approximately 0 + 2 hours, 13 minutes.
Areas that might require Evacuation: In the City of San Juan Capistrano, the flood plain/inundation path might impact all areas adjacent to Oso, Trabuco, and San Juan Creeks towards the Pacific Ocean.
Upper Oso Reservoir - is an earth filled structure constructed in 1979 for the purpose of seasonal storage of recycled irrigation water for Santa Margarita Water District and Moulton Niguel Water District. It is owned and maintained by the Santa Margarita Water District. Its
August 2019 125 City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
location is in the northeast section of Mission Viejo bounded by El Toro Road on the north and Santa Margarita Parkway on the south. It is 60 feet high and has a crest length of approximately 600 feet. When completely filled, it has a storage capacity of about 4,000 acre feet with a surface area of approximately 100 acres.
Areas of Inundation: Should a breach in the reservoir occur, the water released will result in a flood path south under Santa Margarita Parkway through a natural drainage, Oso Creek to the Youth Park at Olympiad Road and Melinda. The water will then travel through a culvert ten (10) feet in diameter to Lake Mission Viejo, then spill over at the south dam face and around the east side at Calle Azorin. Water will travel through Casa Del Sol Golf Course, then through the Oso Creek bed to Interstate 5, and south until it meets Trabuco Creek. From Trabuco Creek, it will merge with San Juan Creek and eventually flow into the Pacific Ocean at Doheny State Beach in the City of Dana Point. Depths at peak flow range from 10 to 45 feet. The flood wave would reach the northern boundary of the City of San Juan Capistrano at approximately 0 + 1 hour, 30 minutes and Doheny State Beach at approximately 0 + 2 hours, 20 minutes.
Areas that might require Evacuation: The flood plain/inundation path might impact all areas adjacent to Oso and Trabuco Creeks and that portion of San Juan Creek south of Trabuco Creek as it moves towards the Pacific Ocean. Past Occurrences of Flooding San Juan Creek and Trabuco Creek Channels over the years have sustained numerous damages caused by heavy rainfall, with the most recent damage occurring in January 2005, December 2010, and January 2017. In June, the heavy rains caused the collapse of a hillside along Avenida Placida. There were approximately 45,000 cubic yards of land slide debris, which impacted an existing drainage basin and water lines in the area.
Table 3.15 lists selected flood damage in Orange County from 1884 to 2017.
Table 3.15: Selected Flood Data from 1884 to 2017 Year Description
The Santa Ana Journal reported in the May 28, 1884 edition that 28.82 inches of rain fell in San Juan 1884 Capistrano between October 2, 1883 and March 27, 1884. Many bridges were lost including the U.S. Highway 101 (present day Camino Capistrano) bridge 1916 over San Juan Creek and the railroad bridges over San Juan and Trabuco Creeks. 1927 The railroad bridges over San Juan and Trabuco Creeks were washed out again. The San Juan Capistrano Coastline Dispatch edition of February 12, 1937 reported "San Juan 1937 Capistrano became an isolated community about 8 pm Saturday when bridges began going out".
The six-day rainfall for the City totaled 9.2 inches. The San Juan Capistrano Coastline Dispatch edition of March 4, 1938 reported, "Flood waters bring tragedy, as two men drown while working to save 1938 pipeline. S.M. Bathgate and C.V. Parks had been drowned in the raging floodwater of Oso Arroyo at a point above its confluence with Trabuco Creek".
August 2019 126 City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Year Description
1943 Both approaches to the railroad bridge over Oso Creek were washed out.
1966 Ganado Drive Bridge over San Juan Creek collapsed.
The Camino Capistrano Bridge over Trabuco Creek failed due to undercutting of the foundations. Bank erosion destroyed lands adjacent to the streams especially in the area upstream from 1-5 on San Juan 1969 Creek and upstream from Del Obispo Street on Trabuco Creek. Several buildings were lost due to bank erosion, sewer mains were washed out, sewage treatment plants were damaged, and the City's sole water supply line was ruptured. In February, extensive damage throughout the City was caused by excessive rainfall and flooding. All three creeks experienced high floodwaters and erosion to banks and adjacent properties. Numerous 1980 sewer lines were broken, storm drains were plugged, streets buckled, and sidewalks cracked. In addition to heavy siltation and run off that caused mud damage to many properties, a number of slopes failed contributing to excessive debris on adjoining properties and on public streets.
1983 High water flow in Trabuco Creek eroded soil surrounding a domestic water pipe causing breakage.
In December, high floodwaters in Trabuco Creek undermined the foundations to the Descanso 1997 Pedestrian bridge, exposing and eroding the bridge footings (pilings) threatening the bridge and the adjacent public bike path. The bridge was moved 150 feet north and resecured.
In February, a State of Emergency was declared in Orange County due to the impacts from El Niño storms. Multiple mudslides, landslides, fallen trees, collapsed walls, and miscellaneous debris caused 1998 hazards throughout the City. In addition, concrete slope channel lining in Trabuco Creek north of the San Juan Creek confluence were dislodged. Although the Creek did not overflow in this section, as a precaution, several units in the adjacent mobile home park were temporarily evacuated.
In January/February, heavy rainfall impacted the area causing two areas to slide. Two disaster periods were declared by the Federal Emergency Management Agency as DR 1577 (January) and DR 1585 (February). There was flooding and damage to recreational trails, and torrential rains collapsed 2005 sections of San Juan Creek. Known costs for repairs: DR 1577: $1,335,897.01 DR 1585: $1,272,448.33
In January, 2010, a series of strong storms pounder Orange County with fierce winds and heavy rain, causing downed power lines and flooded streets. 2010 DR 1952 – 2010 Severe Storms – flooding, landslides, mud flows, and trees on roadways Large Projects: $145,255.75 Small Projects: $90,440.88
Storm produced excessive rains/flooding/flows within San Juan Creek that washed away dirt crossing and culverts in the area perpendicular to and below mid-point of Reata Park’s easterly boundary. Storm produced excessive rains/flows that washed away chips from play area and damaged underlying 2017 ground and fabric at Mission Bell Park located at 33121 Alipaz Street and Acu Park located at 27722 Camino Las Ramblas. Storm produced excessive rains/flows that leaked into/through roof, wall framing, soffits, and onto flooring, causing damage to the La Sala Auditorium located at 31495 El Camino Real, northerly portion of the SJC Library facility.
August 2019 127 City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) San Juan Capistrano Declared Disasters
Federally Declared Disasters as a result of severe storms and flooding in San Juan Capistrano occurred in: 1969, 1978, 1980, 1983, 1992, 1993, 1995, 1998, 2005, 2010, as well as 2017. These conditions caused public and private losses, particularly in the highly urbanized parts of floodplains.
Table 3.16: Declared Disasters as a result of Severe Storms and Flooding in San Juan Capistrano Disaster Number Year Description
DR 935 - 1992 1992 Severe Storms – Flooding, Landslides, Mud flows
DR 979 - 1993 1993 Severe Storms – Flooding, Landslides, Mud flows
DR 1044 and 1046-1995 1995 Severe Storms – Flooding, Landslides, Mud flows
DR 1203-1998 1998 Severe Storms – Flooding, Landslides, Mud flows
Severe Storms – Flooding, Landslides, Mud flows DR 1577 and DR 1585-2005 2005 Approximately $5 million funded of the nearly $6 million costs.
Severe Storms – Flooding, Landslides, Mud flows, Trees on DR 1952-2010 2010 roadway
Trees on cars on Del Obispo Street, at Capistrano Home DR 4305-2017 Jan 2017 Center.
CDAA 2010-02 Jan 2010 Severe Storms – Flooding, Landslides, Mud flows
CDAA 2010-17 Dec 2010 Severe Storms – Flooding, Landslides, Mud flows
Existing Flood Mitigation Activities The City of San Juan Capistrano has designated a Floodplain Administrator who regulates land use through the San Juan Capistrano Municipal Code, Title 8: Building Regulations; Chapter 11: Floodplain Management was adopted by Ordinance No. 627 on May 3, 1988 and amended by Ordinance 1067 on May 7, 2019. Probability of Future Occurrence FEMA defines flood zones based on the probability of occurrence, expressed in a percentage of the chance of a flood of a specific extent occurring in any given year. For areas located within the 100-year flood zone, there is a 1 percent annual chance in a given year that this area will be inundated by flood waters. For areas located within the 500-year flood zone, this probability decreases to 0.2 percent. Due to the history of flooding events in San Juan Capistrano, there is a probability of future occurrences.
August 2019 128 City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) Potential Impact Critical Facilities
Fourteen of the City’s fifty critical facilities are located in the 100-year flood zone including City Hall, Police Service, Public Works/Utilities, and the Ground Water Recovery Plant. The risk of flooding poses a total aggregate financial exposure for the facilities and their contents at approximately $44.3 million, as reflected in Table 3.17.
Table 3.17: San Juan Capistrano Critical Facilities Located in or Near a 100-Year Flood Zone Replacement Contents Potential Map # Facility Value Value Loss
1 $6,000,000 $3,000,000 $9,000,000 City Hall 2 $859,760 $667,666 $1,527,426 Utilities Yard 3 $675,137 $37,859 $712,996 Dance Hall/Police Services 4 $505,150 $867,709 $1,372,859 Utilities Department Offices 8 $27,042,929 $0 $27,042,929 Groundwater Recovery Plant (GWRP) 9 $525,574 $822,313 $1,347,887 Public Works Yard 10 $3,208,197 $34,364 $3,242,561 Old Fire Station Complex 14 South Cooks Well na na na 17 St. Margaret's Episcopal School * * * 31 Tirador Well na na na 33 Well #5A na na na 44 Dance Hall Well na na na 46 Strawberry Hill Pump Station na na na 47 $0 $132,823 $132,823 Rosenbaum Lift Station $38,816,747 $5,562,734 $44,379,481 Total Replacement value information based on City insured values for each facility. * - Not City Owned na - No Data Available
August 2019 129 City of San Juan Capistrano Local Hazard Mitigation Plan Map 3.12: FEMA 100-Year Flood Zones
Number Name Address 1 City Hall 32400 Paseo Adelanto 2 Utilities Yard 32450 Paseo Adelanto 3 Dance Hall\Police Services 32506 Paseo Adelanto 4 Utilities Department Offices 32450 Paseo Adelanto 8 Groundwater Recovery Plant (GWRP) 32470 Paseo Adelanto 9 Public Works Yard 32450 Paseo Adelanto 10 Old Fire Station Complex 31421 La Mantanza Street 14 South Cooks Well 27396 Calle Arroyo 17 St. Margaret's Episcopal School 31641 La Novia Avenue 31 Tirador Well 27122 Paseo Tirador 33 Well #5A 27802 Calle Arroyo 44 Dance Hall Well 32470 Paseo Adelanto 46 Strawberry Hill Pump Station 31261 El Horno Street 47 Rosenbaum Lift Station 29688 Rancho Viejo Road
August 2019 130
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) Climate Change Considerations Although Southern California is likely to experience a decrease in overall precipitation levels due to climate change, the region is also expected to see an increase in the number of extreme precipitation events. A meteorological phenomenon known as the atmospheric river, a narrow stream of extremely moist air, is frequently responsible for the more intense storms that strike California. Atmospheric rivers generally deliver high levels of precipitation, up to 50 percent of the state’s total precipitation in any given year.
Some recent studies indicate that atmospheric rivers may strengthen as a result of climate change. This is expected to lead to an increase in the number of storms caused by atmospheric rivers. Additionally, there is some indication that the most powerful atmospheric river storms will increase in intensity. Although there are no specific flooding projections for the City of San Juan Capistrano, flood events are expected to become more frequent, and it is possible that the areas subject to flooding could expand. Summary Vulnerability/Risk Assessment Significant damage can occur to utilities during flooding events. When water rushes through a City in this way, it takes everything in its path, which could include any aboveground infrastructure such as electricity line poles and traffic signal control boxes. The water sometimes mixes with sediment, oil, and/or sewage, which can impact roads, block storm drains, and further exacerbate flood damage. Infrastructure located underground may be damaged due to inundation or could be exposed, requiring repair or reconstruction. Ultimately, utilities located within flood prone areas should be designed and constructed to accommodate these concerns when feasible. For communities where above ground infrastructure is located, flood proofing techniques should be identified to ensure continued operations during flood events.
August 2019 131
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) Terrorism Definition
Terrorism is the use of force or violence against persons or property in violation of the criminal laws of the United States for purposes of intimidation, coercion, or ransom.60
Existing Terrorism Mitigation Activities
Through collaboration with county and federal agencies, as well as through the implementation of the Terrorism Liaison Officer (TLO) program, specially trained individuals gather and share intelligence deemed to be a threat to the public. Personnel are kept apprised of the current, relevant international and national information to maintain the highest possible degree of readiness and tactical awareness. First responders are trained to handle all types of terrorist events whether they involve chemicals, biological weapons, radiation, nuclear devices, and/or explosives. First responders take initial actions and call for specialized resources depending upon the type of incident they face and notify appropriate local, State, and Federal agencies to coordinate the response.
Vulnerability/Risk Assessment The City of San Juan Capistrano’s plans for responding to acts of terrorism are considered classified information that is coordinated by the Orange County Sheriff’s Department in coordination with City, State, and Federal law enforcement agencies.61
60 http://www.ocgov.com/about/emergency/terrorism, (Accessed February 11, 2019) 61 City of San Juan Capistrano, Emergency Operations Plan, May 2018
August 2019 132
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) Transportation and Hazardous Materials Incidents General Background
Transportation incidents encompass many threats, such as hazardous materials incidents that may require localized evacuation. Hazardous substances pose a threat due to its inherent characteristics. The actual impact depends on where the incident occurs and on weather, geography, population, and other site-specific conditions that influence their behavior in the environment and can vary greatly. Whether at a fixed site, or as part of a transportation system, a hazardous materials incident would have the potential to disrupt daily life and business in the City of San Juan Capistrano.
“Hazardous materials” covers a large number of substances that are a danger to the public. These include toxic metals, chemicals, gases, flammable and/or explosive liquids and solids, corrosive materials, infectious substances, and radioactive materials.
In addition to the immediate risk to life safety, public health, and air quality, the potential for water source contamination, and the potential environmental impacts, there is also concern over the long‐term public health and environmental impacts that may result from the sustained use of, or exposure to, certain substances. An incident could result in the evacuation of a few people, a section of a facility, or an entire neighborhood. Transportation and Hazardous Materials Incidents Hazard Profile Community Issues Hazardous materials are transported through, adjacent to, or over the City via three major modes of transportation (highways, city streets, subsurface pipelines, and rail lines). Air
The airspace surrounding San Juan Capistrano is among some of the busiest in the state. John Wayne Airport is the major commercial and private airport in Orange County. Orange County is located in one of the busiest areas in the world. Two of the busiest aviation areas in the world are within a 40-mile radius along with a major US military Training Facility and a multitude of transient aviation traffic. The number of civilian aircraft, public use aircraft, and military aircraft operating or transiting over San Juan Capistrano heightens the chances of aviation related accidents, yet aircraft accidents occur infrequently when compared to the number of air operations.
August 2019 133
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Rail
The rail line traverses the City of San Juan Capistrano for a distance of 4.7 miles; the rail line direction is in close proximity to the I-5 Freeway. Amtrak, a national passenger rail service, and Metrolink, a regional passenger rail service, serve the City. The Burlington Northern & Santa Fe Railway (BNSF), a national freight service, operates freight trains on the same tracks. Amtrak passes through the City or makes stops 22 times each day Monday-Thursday and 24 times each day Friday-Sunday. Metrolink operates 16 trains Monday-Friday, except for some holidays; there is no service on weekends. The BNSF traffic varies from 3 to 7 trains every day of the week; traffic depends on ship loading in San Diego. However, all freight trains originate and terminate outside the City; there are no scheduled stops in the City. Thus, due to freight service, virtually every industry and business passes through the City. Highways Transportation corridors for the City of San Juan Capistrano include CA Interstate 5, a major north–south route of the Interstate Highway System in California. The California Highway Patrol has designated this highway as a radioactive materials transportation corridor, and the U.S. Department of Transportation has identified Interstate 5 as the third busiest transportation corridor in the county. State Route Highway 74 begins at an interchange with Interstate 5 in the City of San Juan Capistrano and heads east, loosely paralleling San Juan Creek. The highway leaves the San Juan Capistrano City limits near the Cleveland National Forest. Pipelines According to the US Department of Transportation (DOT) National Pipeline Mapping System Public Viewer, there is one active underground hazardous liquid pipeline north and east of the City of San Juan Capistrano designated for crude oil and refined petroleum product, and one major, high-pressure natural gas pipeline. The California Public Utilities Commission ensures that natural gas pipeline systems are designed, constructed, operated, and maintained according to the safety standards set by the CPUC and the federal government. Location and Extent The locations in Table 3.18 have the potential of hazardous materials releases. Business and Industrial Areas Retail, manufacturing, and light industrial firms are areas of concern. These facilities have the highest concentration of hazardous materials at fixed facilities in the planning area due to their manufacturing operations. Each business is required to file a detailed plan with the Orange County Environmental Health Care Agency regarding materials on-site and safety measures taken to protect the public.
August 2019 134
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Table 3.18: Businesses in San Juan Capistrano that use Reportable Quantities of Hazardous Materials Name Address Material Quantity
Clean Energy 26571 Junipero Compressed Natural Gas 30,000 cubic feet
Linde 26572 Junipero Serra Hydrogen Gas 26,304 cubic feet
Coastal Blue Corp. 33091 Calle Perfecto Ammonia Unknown
Agricultural Areas
Accidental releases of pesticides, fertilizers, and other agricultural chemicals may be harmful to both humans and the environment. Agricultural pesticides are transported daily in and around the planning area en route to destinations in rural areas. Illegal Drug Operations
Illegal operations such as laboratories for methamphetamine can pose a threat. Laboratory residues are often dumped along roadways or left in rented hotel rooms, creating a serious health threat to unsuspecting individuals and to the environment. Illegal Dumping Sites
Hazardous wastes such as used motor oil, solvents, or paint are occasionally dumped in remote areas or along roadways, creating a potential health threat to unsuspecting individuals and to the environment. Transportation Routes
The County’s transportation system consists of a network of federal, state, and county roads, airports, and rail services that all have the potential for hazardous materials incidents:
Interstate 5 and State Route 74 Railroad lines— Amtrak, Metrolink, and Burlington Northern & Santa Fe Railway (BNSF) operate freight trains on the same tracks Airports—John Wayne Airport, Camp Pendleton Pipelines
There are two high pressure pipelines transporting hazardous materials through or near San Juan Capistrano. Map 3.9 shows these pipelines based on information provided by the National Pipeline Mapping System, which is available to the general public.
August 2019 135
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) Past Occurrences of Transportation and Hazardous Materials Incidents
Table 3.19: List of Hazardous Materials Spills that Ooccurred Within the City from 2010 to 201862
Date Time Substance Qty. Measure Location Spill Site
2018
Vehicle vs Freight 6/11/18 2110 N/A N/A DOT 026787A Rail Road Train
Bldg B. Special Chemistry Lab, 3/16/18 930 Amonia (gas) 1 Lbs. Merchant/Business 33608 Ortega Hwy.
Esencia Street, 100 feet north 2/14/18 2195 Sewage 1600 Gal(s) Road of cal camp
2017
12/22/17 1630 Sewage 400 Gal(s) 31293 Ortega Hwy. Other
8/24/17 800 Refrigerant gases Unknown Unknown 33961 Doheny Park Merchant/Business
2016
MP 194.32 Orange 8/6/16 1425 Train vs Vehicle N/A N/A Rail Road Subdivision
#429, 33961 Doheny Park 4/23/16 1947 Unleaded 2 Gal(s) Service Station Road
1/28/16 1353 Weed Killer 1 Gal(s) South Bound 5 at Avery Road
2015
2/7/15 200 Refrigerant Gases 240 Lbs. 33961 Doheny Park Rd Merchant/Business
33961 Doheny Park Rd, 2/7/15 200 Freon 240 Lbs. Merchant/Business Costco #429
Refrigerant Gas - 33961 Doheny Park Rd 2/21/15 300 240 Lbs. Merchant/Business R22 (Costco Warehouse #429) Train vs 4/16/15 1120 N/A N/A MPM 203 Sub division Orange Rail Road Trespasser 2014 Train vs 4/17/14 1602 N/A N/A MP 199.8 Orange Sub Rail Road Trespasser Train vs 4/17/14 1602 N/A N/A MP 199.8 Rail Road Trespasser 5/20/14 1004 Unknown Unknown Unknown Orinda Road Residence
62 https://www.caloes.ca.gov/for-individuals-families/hazardous-materials/spill-release-reporting
August 2019 136
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Date Time Substance Qty. Measure Location Spill Site
28793 Ortega Hwy, near Treatment/Sewage 6/4/14 715 Sewage 50,000 Gal(s) Chiquita Treatment Plant Facility
26701 Verdugo St at MPM 6/13/14 1300 Lube Oil 100 Gal(s) Rail Road 197.1 on the Orange Sub Div
8/21/14 1815 Diesel 50 Gal(s) NB I-5 JSO exit 81 Road Train vs 11/10/14 116 N/A N/A MP 199.39 of the Orange Sub Rail Road Trespasser 2013 MP 194.32, Camino 5/22/13 1635 Train vs Vehicle N/A N/A Rail Road Capristrano St Orange Sub-division at MP 5/22/13 1630 Train vs vehicle N/A N/A Rail Road 194.5 10.0 rem Radiation Monitor background, Prima Land Fill, 32250 La 6/1/13 1230 surface 5.7 Unknown Other at a land fill rems (high of Pata Avenue 20's)
9/15/13 1900 Sewage Unknown Unknown 26282 Oso Rd Merchant/Business 2012 Sewage- Treatment/Sewage 1/19/12 1700 50 Gal(s) 33608 Ortega Highway secondary effluent Facility 200,000 to 25601 Camino Del Avion, 10/17/12 1500 Sewage Gal(s) School 300,000 Marco Forester Middle School, Merchant/Business, 10/30/12 1449 Natural Gas Unknown Unknown 32250 La Pata Ave. Residence,School 2011 Treatment/Sewage 3/15/11 825 Sewage - Raw 5000 Gal(s) 28793 Ortega Hwy Facility San Juan Basin Authority 4/23/11 955 Recycled Water 50 Gal(s) Ground Water Recovery Plant, Other 32470 Paseo Adelanto MPM 199.65 on the Orange Train vs 7/2/11 2148 N/A N/A Subdivision, Stonehill Road Rail Road Trespasser Overpass 9/23/11 1230 Mineral Oil 50 Gal(s) 29931 Camino Capistramo Other NB on I-5 south of the Camino 10/25/11 1025 Muriatic Acid 5 Gal(s) Road Capistrano offramp 12/31/11 1612 Train vs Auto N/A N/A Oso Road grade crossing Rail Road 2010 4/9/10 1110 Train vs Vehicle N/A N/A Areo Puerto road crossing Rail Road 12/22/10 1200 Sewage 50,000 Gal(s) 75 feet east Via Tonada Other
N/A - No Data Available
August 2019 137
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) Existing Mitigation Efforts Hazardous Materials Business Emergency Plan (HMBEP)
Assembly Bill (AB) 2286 went into effect January 1, 2009. The law requires all regulated businesses and all regulated local government Unified Program Agencies (UPAs) to use the Internet to electronically report and submit required Unified Program information previously recorded on paper forms. This includes facility data regarding hazardous materials regulatory activities, chemical inventories, underground and aboveground storage tanks, and hazardous waste generation. It also includes UPA data such as inspections and enforcement actions.
All businesses must submit and report Unified Program-related information to either the statewide California Environmental Reporting System (CERS) or to the local UPA’s reporting web portal, if provided.63 The purpose of the program is to prevent or minimize damage to public health and safety and the environment from a release or threatened release of hazardous materials. These locally implemented programs also satisfy federal community right-to-know laws.
The Hazardous Materials Business Emergency Plan (HMBEP) program requires businesses that handle hazardous materials (including hazardous wastes) or extremely hazardous substances at reportable quantities to submit a HMBEP in the Statewide CERS.
The reportable quantities amounts are equal to or greater than:
55 gallons of a liquid 500 pounds of a solid 200 cubic feet of compressed gas Extremely hazardous substances above the threshold planning quantity
The Environmental Health Division was designated as the Certified Unified Program Agency (CUPA) for the County of Orange by the State Secretary for Environmental Protection on January 1, 1997. The Hazardous Material Disclosure and Business Emergency Plan programs require Orange County businesses to:
Inventory their hazardous materials Develop a site map Develop an emergency plan Implement a training program for employees
63 California Environmental Protection Agency https://calepa.ca.gov/cupa/ereporting/
August 2019 138
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
The Orange County CUPA verifies information disclosed by businesses and provides it to agencies that are responsible for the protection of public health and safety and the environment, such as fire departments, hazardous materials response teams, and other local environmental regulatory groups. The public also has a right to review this information, with the exception of documents containing trade secrets or other confidential information. Probability of Future Occurrence Although past occurrences can be an indicator of future impacts, in the case of hazardous materials spills, the City is constantly improving the mechanisms by which it approves and regulates businesses that use hazardous materials. In addition, technological advances and increases in industry standards are also improving safety and further preventing/minimizing potential releases of hazardous materials. As a result, it is anticipated that future incidents will decrease over time as newer technologies, standards, and regulations are put in place. Potential Impact Critical Facilities at Risk Twenty one of the City’s fifty critical facilities are located within 1,000 feet of a rail line, hazardous materials pipeline, or a business with reportable quantities of hazardous materials as noted in Table 3.20 and Map 3.13.
Table 3.20: Critical Facilities Adjacent to a Large Quantity Hazard Materials Site or Pipeline (within 1,000 ft.) Replacement Contents Potential Map # Facility Value Value Loss 1 City Hall $6,000,000 $3,000,000 $9,000,000
2 Utilities Yard $859,760 $667,666 $1,527,426
3 Dance Hall/Police Services $675,137 $37,859 $712,996
4 Utilities Department Offices $505,150 $867,709 $1,372,859
5 OCFA Fire Station #7 * * * 8 Groundwater Recovery Plant (GWRP) $27,042,929 $0 $27,042,929
9 Public Works Yard $525,574 $822,313 $1,347,887
10 Old Fire Station Complex $3,208,197 $34,364 $3,242,561
12 San Juan Capistrano Regional Library $7,800,083 $50,000 $7,850,083
13 Mariners Church Ocean Hills * * * 15 JSerra Catholic High School * * *
August 2019 139
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Replacement Contents Potential Map # Facility Value Value Loss 29 CVWD Well #1 na na na
32 Kinoshita Well na na na
34 SJBA Well #4 na na na
35 North Open Space Well $0 $1,292,665 $1,292,665
43 Rosenbaum Well #1 $0 $1,292,665 $1,292,665
44 Dance Hall Well na na na
45 Mission Street Well na na na
47 Rosenbaum Lift Station $0 $132,823 $132,823
48 Master Meter CM10 ETM na na na
49 Tricities Interconnect na na na
Total Potential Losses $46,616,830 $8,198,064 $54,814,894 Replacement value information based on City insured values for each facility. * - Not City Owned na - No Data Available
August 2019 140 City of San Juan Capistrano Local Hazard Mitigation Plan Map 3.13: Hazardous Materials Sites within 1,000 feet of Critical Facilities
Number Name Address 1 City Hall 32400 Paseo Adelanto 2 Utilities Yard 32450 Paseo Adelanto 3 Dance Hall\Police Services 32506 Paseo Adelanto 4 Utilities Department Offices 32450 Paseo Adelanto 5 OCFA Fire Station #7 31865 Del Obispo Street 8 Groundwater Recovery Plant (GWRP) 32470 Paseo Adelanto 9 Public Works Yard 32450 Paseo Adelanto 10 Old Fire Station Complex 31421 La Mantanza Street 12 San Juan Capistrano Regional Library 31495 El Camino Real 13 Mariners Church Ocean Hills 32222 Del Obispo Street 15 JSerra Catholic High School 26351 Junipero Serra Road 29 CVWD Well #1 32510 Del Zura 32 Kinoshita Well 32784 Alipaz Street 34 SJBA Well #4 32703 Vivente De Marlita 35 North Open Space Well 30291 Camino Capistrano 43 Rosenbaum Well #1 29688 Rancho Viejo Road 44 Dance Hall Well 32470 Paseo Adelanto 45 Mission Street Well 26601 Mission Street 47 Rosenbaum Lift Station 29688 Rancho Viejo Road 48 Master Meter CM10 ETM 28901 Camino Capistrano 0 49 Tricities Interconnect Del Obispo @ Stonehill Drive
August 2019 141
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Climate Change Considerations Anticipating that precipitation regimes may change in the future as a result of climate change, there may be greater opportunity for the release of hazardous materials to enter local waterways and the groundwater aquifer. It is anticipated that if this concern increases, the City and other regulating agencies would revisit procedures and practices in place to ensure the greatest amount of protection occurs. Summary Vulnerability/Risk Assessment Table 3.20 and Map 3.13 identify critical facility locations that could be exposed to hazardous materials releases during a disaster event. The total potential loss shown in the table is based on the assumption that all facilities within 1,000 feet of a hazardous materials facility would be impacted during a hazardous materials release/event and shows the maximum potential losses. While this is possible, actual losses will vary based on the location and magnitude of the event.
August 2019 142
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) Landslide General Background The U.S. Geological Survey definition of landslides includes a wide range of ground movement, such as rock falls, deep failure of slopes, and shallow debris flows. Although gravity acting on an over-steepened slope is the primary reason for a landslide, there are other contributing factors. Landslides and mudslides can be initiated by storms, earthquakes, fires, volcanic eruptions, or human modifications of the land.
When landslides occur in response to such changes as increased water content, earthquake shaking, addition of load, or removal of downslope support, they deform and tilt the ground surface. The result can be destruction of foundations, offsets of roads, breaking of underground pipes, or overriding of downslope property and structures. They can move rapidly down slopes or through channels and can strike with little or no warning at avalanche speeds, posing a serious hazard to properties on or below hillsides.
The USGS defines land subsidence as the loss of surface elevation due to the removal of subsurface support. In California, the two principal causes for land subsidence are aquifer compaction due to excessive groundwater pumping and decomposition of wetland soils exposed to air after wetland conversion to farmland. Definition
Landslide - The movement of masses of rock, debris, or earth down a slope. Landslides are a type of "mass wasting", which denotes any down slope movement of soil and rock under the direct influence of gravity. The term "landslide" encompasses events such as rock falls, topples, slides, spreads, and flows. Landslides can be initiated by rainfall, earthquakes, volcanic activity, changes in groundwater, disturbance and change of a slope by man-made construction activities, or any combination of these factors.
Mass Movement - A collective term for landslides, debris flows, and sinkholes.
Mudslide (or Debris Flow) - A river of rock, earth, organic matter, and other materials saturated with water. Mudslides develop in the soil overlying bedrock on sloping surfaces when water rapidly accumulates in the ground, such as during heavy rainfall or rapid snowmelt. Water pressure in the pore spaces of the material increases to the point that the internal strength of the soil is drastically weakened. The soil’s reduced resistance can then easily be overcome by gravity, changing the earth into a flowing river of mud or “slurry”.
August 2019 143
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) Landslide Threat to the City of San Juan Capistrano
Landslides are a serious geologic hazard in almost every state in America. Nationally, landslides cause 25 to 50 deaths each year. The best estimate of direct and indirect cost of landslide damage in the United States ranges between $1 and $2 billion annually. As a seismically active region, California has had a significant number of locations impacted by landslides. Some landslides result in private property damage; other landslides impact transportation corridors, fuel and energy conduits, and communication facilities. They can also pose a serious threat to human life.
Landslides can be broken down into two categories: Rapidly Moving (generally known as debris flows) Rapidly moving landslides or debris flows present the greatest risk to human life, and people living in or traveling through areas prone to rapidly moving landslides are at increased risk of serious injury. Slow Moving Slow moving landslides can cause significant property damage but are less likely to result in serious human injuries.
In the City of San Juan Capistrano, landslide and debris flows are the dominant geologic hazard risks. This is based on abundant shales and siltstones that underlie the City's hills that are highly porous and do not hold together well when wet. This can lead to slope instability and landslides. In addition, factors that contribute to slope instability and landslides include rainfall, the City's complex water distribution system, and earthquakes. Debris flows can occur rapidly and without warning during periods of exceptionally high rainfall. Although rockfall hazards are low in the City, mudflows are more likely to occur. Impacts of Development
Although landslides are a natural occurrence, human impacts can substantially affect the potential for landslide failures in the City of San Juan Capistrano. Proper planning and geotechnical engineering can be exercised to reduce the threat of safety of people, property, and infrastructure. Excavation and Grading
Slope excavation is common in the development of home sites or roads on sloping terrain. Grading these slopes can result in some slopes that are steeper than the pre•existing natural slopes. Since slope steepness is a major factor in landslides, these steeper slopes can be at an increased risk for landslides. The added weight of fill placed on slopes can also result in an increased landslide hazard. Small landslides can be fairly common along roads, in either the road cut or the road fill. Landslides occurring below new construction sites are indicators of the potential impacts stemming from excavation.
August 2019 144
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Drainage and Groundwater Alterations
Water flowing through or above ground is often the trigger for landslides. Any activity that increases the amount of water flowing into landslide-prone slopes can increase landslide hazards. Broken or leaking water or sewer lines can be especially problematic, as can water retention facilities that direct water onto slopes. However, even lawn irrigation in landslide prone locations can result in damaging landslides. Ineffective storm water management and excess runoff can also cause erosion and increase the risk of landslide hazards. Drainage can be affected naturally by the geology and topography of an area. Development that results in an increase in impervious surface impairs the ability of the land to absorb water and may redirect water to other areas. Channels, streams, ponding, and erosion on slopes all indicate potential slope problems. Road and driveway drains, gutters, downspouts, and other constructed drainage facilities can concentrate and accelerate flow. Ground saturation and concentrated velocity flow are major causes of slope problems and may trigger landslides. Changes in Vegetation
Removing vegetation from very steep slopes can increase landslide hazards. Areas that experience wildfire and land clearing for development may have long periods of increased landslide hazard. Also, certain types of ground cover have a much greater need for constant watering to remain green. Changing away from native ground cover plants may increase the risk of landslide. Landslide Hazard Profile Community Landslide Issues
Landslides can affect utility services, transportation systems, and critical lifelines. Communities may suffer immediate damages and loss of services. Disruption of infrastructure, roads, and critical facilities may also have a long-term effect on the economy. Utilities, including potable water, wastewater, telecommunications, natural gas, and electric power, are all essential to service community needs. Loss of electricity has the most widespread impact on other utilities and on the whole community. Natural gas pipes may also be at risk of breakage from landslide movements as small as an inch or two. Roads and Bridges
It is not cost effective to mitigate all slides because of limited funds and the fact that some historical slides are likely to become active again even with mitigation measures. The city Roads Division alleviates problem areas by grading slides and by installing new drainage systems on the slopes to divert water from the landslides. This type of response activity is often the most cost-effective in the short-term but is only temporary. Unfortunately, many property owners are unaware of slides and the dangers associated with them.
August 2019 145
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Lifelines and Critical Facilities
Lifelines and critical facilities should remain accessible, if possible, during a natural hazard event. The impact of closed transportation arteries may be increased if the closed road or bridge is critical for hospitals and other emergency facilities. Therefore, inspection and repair of critical transportation facilities and routes is essential and should receive high priority. Losses of power and phone service are also potential consequences of landslide events. Due to heavy rains, soil erosion in hillside areas can be accelerated, resulting in loss of soil support beneath high voltage transmission towers in hillsides and remote areas. Flood events can also cause landslides, which can have serious impacts on gas lines that are located in vulnerable soils. Location and Extent of Landslide Hazard
The City's foothill areas are vulnerable to slope instability. Furthermore, some of the residential construction in the foothills of San Juan Capistrano occurred prior to the development and enforcement of stronger grading codes in the 1970's and before heightened awareness of slope stability issues that has resulted from the periodic intense rainstorms of the last 30 years. Consequently, there are older residences built in or near natural drainage courses and steep slopes that may be at risk from slope failures. Past Occurrences of Landslides No significant landslides have occurred in the City since 2005; however, a large percentage of the City is vulnerable to landslides.
Table 3.21: Previous Landslides in San Juan Capistrano Year Description
Landslides took place in a southern portion of the City referred to as Forster Canyon Planned Community, North Valley. A section of the western slope failed and affected an existing avocado grove on an adjoining property. In addition, Via La Mirada and Avenida Calita residential properties were impacted when a large portion of the eastern North Valley slope failed. These slides are 1998 described as bedrock block failures and are referred to as the "La Mirada/Calita" and the "Avocado" landslides. To mitigate future failures, remedial grading and construction of buttress fills were implemented to enhance slope stability conditions. A catchment basin has been added to catch and control debris resulting from future erosion or possible instability of the subject slope area.
August 2019 146
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Year Description
In January/February 2005, a slope failure occurred at the north end of Avenida Placida, undermining an existing trail/access road. This failure occurred when the region was experiencing record rainfall. On August 19, 2005, an engineering geologist performed a field reconnaissance visit to the site and determined a slope failure on the order of 120 feet wide and 70 feet tall was observed to underline the existing public access trail. A nearly vertical, 20-foot high head-scarp along the eastern limit of the slide had encroached 3-5 feet into the trail. Fractures oriented parallel to the head-scarp were visible within the trail. The toe of the landslide extends onto a relatively flat bench area at the top of the engineered slope ascending above Avenida Placida. Multiple broken irrigation lines were observed at the edge of the landslide. The manufactured fill slope below the landslide area and within the limits of the tract consists of a buttress keyway for mitigation of one or more of the lower elevation of clay beds. Clay beds daylighted within the open-space above the development boundaries can be expected to cause failures over time. The northeastern portion of 2005 the clay bed on which the failure is estimated to have occurred had previously failed and been provided with a small buttress keyway and sub-drain. The clay bed is estimated to form the base of the failure just beyond the furthest southeastern limit of the small keyway. Mitigation: The mitigation project included both geotechnical work to clean up an ancient landslide that moved and the addition of caissons and tie backs to protect an existing reservoir and pipeline system that included water, sewer, and storm drain lines serving Paseo Activo as they travel down to Camino Las Ramblas. The Placida slide is still active.
In June, a hillside along Avenida Placida on the east side of the City near San Juan Hills Estates left a large amount of damage. A major water pipeline serving 2,000 residents of the City needed to be stabilized and an existing drainage basin was filled with debris. Mitigation work included putting caissons into the ground. $1.6 million was approved by FEMA for these efforts.
August 2019 147
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) Existing Landslide Damage Mitigation Activities Landslide mitigation activities include current mitigation programs and activities that are being implemented by the City. The City of San Juan Capistrano Municipal Code addresses development on steep slopes in Title 9: Land Use, Chapter 3: Zoning Districts and Standards: Article 3: Base District Regulations/Standards, Section 9-3.303(c)(2)(F). This section outlines standards for steep slope hazard areas on slopes of 20 percent or more. Generally, the ordinance requires soils and engineering geologic studies for developments proposed on slopes of 20 percent or greater. More detailed surface and subsurface investigations shall be warranted if indicated by engineering and geologic studies to sufficiently describe existing conditions. This may include soils, vegetation, geologic formations, and drainage patterns. Site evaluations may also occur where stability might be lessened by proposed grading/filling or land clearing. Probability of Future Occurrence The potential for slope failure is dependent on many factors and their interrelationships. Some of the most important factors include slope height, slope steepness, sheer strength, and orientation of weak layers in the underlying geologic unity, as well as pore water pressures. Joints and shears, which weaken the rock fabric, allow penetration of water leading to deeper weathering of the rock along with increasing the pore pressures, increasing the plasticity of weak clays, and increasing the weight of the landmass. For engineering of earth materials, these factors are combined in calculations to determine if a slope meets a minimum safety standard. The generally accepted standard is a factor of safety of 1.5 or greater (where 1.0 is equilibrium and less than 1.0 is failure).
Although existing landslides are not widespread in the area, it is probable that many of the steeper hillsides do not meet the minimum factor of safety, and slope stabilization may be needed if development reaches these areas. Natural slopes, graded slopes, or graded/natural slope combinations must meet these minimum engineering standards where they impact planned homes, subdivisions, or other types of developments.
While a quantitative vulnerability assessment (an assessment that describes the number of lives or amount of property exposed to the hazard) has not yet been conducted for the City of San Juan Capistrano landslide events, there are many qualitative factors that point to potential vulnerability. Landslides can impact major transportation arteries, blocking residents from essential services and businesses. Past landslide events have caused major property damage or significantly impacted city residents, and continuing to map city landslide and debris flow areas will help in preventing future loss. Potential Impact
Landslides can present a problem in the City of San Juan Capistrano and may impact the City's infrastructure as well as private property. Although landslides have a low likelihood of occurring in the City, the impacts of even small localized landslides can be very costly in cleanup and repair. Landslides in the City of San Juan Capistrano are primarily caused by heavy rainfall. However, due
August 2019 148
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) to the inconsistent weather patterns of the area, predicting and planning for such events is extremely difficult. Risks to these types of natural hazards are based on the City's history and potential for occurrence. Critical Infrastructure at Risk Fourteen of the City’s fifty critical facilities are located in or near a landslide zone. The risk of landslide poses a total aggregate financial exposure for the facilities and their contents at approximately $41 million as referenced in Table 3.22.
Table 3.22: San Juan Capistrano Critical Facilities Located in or near Landslide Zones Replacement Contents Potential Loss Map # Facility Value Value
16 San Juan Hills High School * * *
18 Reed Reservoir Zone 2 #1 $15,289 $2,827,748 $2,843,037
19 760 Reservoir South $7,184,567 $0 $7,184,567
20 Reed Reservoir Zone 2 #1B $15,289 $1,026,062 $1,041,351
21 Terminal Reservoir #2 na na na
22 Terminal Reservoir #3 $21,115,227 $0 $21,115,227
23 High West Side Reservoir #2 $95,560 $388,244 $483,804
24 High West Side Reservoir #1 $95,560 $323,611 $419,171
26 Zone 3 #2 Reservoir (Lower Hunt Club) $420,454 $1,422,378 $1,842,832
27 Zone 3 #1 Reservoir (Upper Hunt Club) $0 $776,044 $776,044
28 Mission Hills Reservoir na na na
38 Capistrano Royale Pump Station $477,789 $1,292,843 $1,770,632
40 Mission Hills Pump Station $477,789 $1,918,841 $2,396,630
42 Hidden Mountain Pump Station $477,789 $646,511 $1,124,300
Total Potential Losses $30,375,313 $10,622,282 $40,997,595 Replacement value information based on City insured values for each facility. * - Not City Owned na - No Data Available
August 2019 149 City of San Juan Capistrano Local Hazard Mitigation Plan Map 3.14: Potential Landslide Zones in San Juan Capistrano
Number Name Address 16 San Juan Hills High School 29211 Stallion Ridge 18 Reed Reservoir Zone 2 #1 28422 Via Entrada 19 760 Reservoir South 27271 Calle Delgado 20 Reed Reservoir Zone 2 #1B 28422 Via Entrada 21 Terminal Reservoir #2 27100 Highland Drive 22 Terminal Reservoir #3 26861 Mission Hills Drive 23 High West Side Reservoir #2 31572 Aguacate Road 24 High West Side Reservoir #1 31572 Aguacate Road 26 Zone 3 #2 Reservoir (Lower Hunt Club) 30761 Steeplechase Drive 27 Zone 3 #1 Reservoir (Upper Hunt Club) 30561 Steeplechase Drive 28 Mission Hills Reservoir 21800 Highland Drive 38 Capistrano Royale Pump Station 26911 Highland Drive 40 Mission Hills Pump Station 26902 Mission Hills Drive 42 Hidden Mountain Pump Station 31632 Via Cervantes
August 2019 150
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) Climate Change Considerations The link between climate change impacts and the risk of landslides is indirect. One possible consideration is that anticipated changes to precipitation regimes and hydrological patterns could result in a change to groundwater levels. Since landslides are influenced by the presence of shallow subsurface water, an increase in groundwater levels could occur due to new precipitation patterns. The potential change in shallow subsurface water conditions could expand, increasing the risk of future damage to additional structures in the City. In contrast, a reduction in precipitation as a result of climate change could reduce groundwater levels in the future, which could also affect potential for landslide in the city. Vulnerability/Risk Assessment Significant damage can occur to utilities during landslide events. When land moves in this way, it takes everything in its path, which could include any aboveground infrastructure such as electricity line poles and traffic signal control boxes. Landslides can impact roads, block storm drains, and further exacerbate flood damage. Infrastructure located underground may be damaged due to land movement or could be exposed, requiring repair or reconstruction.
August 2019 151
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) Radiological and Nuclear Community Issues San Onofre Nuclear Generation Station (SONGS) is located on the coast of Southern California in San Diego County, approximately 8 miles southeast of the City of San Juan Capistrano (See Map 3.15).
The owner, Southern California Edison (SCE), formally notified the Nuclear Regulatory Commission (NRC) on June 12, 2013 that it had permanently ceased operations. The notification, called a Certification of Permanent Cessation of Power Operations, set the stage for SCE to begin preparations for decommissioning.
Decommissioning is a well-defined NRC process that involves transferring the used fuel into safe storage, followed by the removal and disposal of radioactive components and materials. SONGS stores used uranium fuel on site using a combination of technologies: enclosed, steel-lined pools (spent fuel pools), and sealed stainless steel canisters that are housed in reinforced concrete structures (dry cask storage). As long as used nuclear fuel remains on site at San Onofre, the Independent Spent Fuel Storage installation (ISFSI) will continue to be licensed and inspected by the NRC, and the used nuclear fuel will be maintained and protected by SCE.
SCE has committed to the California Coastal Commission to continue to evaluate potential coastal hazards and will, by 2035, evaluate potential alternative sites at SONGS for the ISFSI.
Coordination, information sharing, and partnership between SCE and local governmental agencies continues through the decommissioning process. Vulnerability/Risk Assessment It is no longer possible to generate a radiological release that would exceed the EPA-400 Protective Action Guide of a 1 REM exposure. Emergency planning zones that once existed have been eliminated via exemptions approved by the Nuclear Regulatory Commission. The NRC has determined that in the unlikely event of losing cooling in the spent fuel pools, there is sufficient time for staff to take appropriate actions, as well as notify local governments while containing the site. SONGS is operating under the NRC approved Permanently Defueled Emergency Plan (PDEP). Once all of the spent nuclear fuel is moved from the spent fuel pools into dry cask storage, SCE will operate under the Independent Spent Fuel Storage Installation Emergency Operations Plan (ISFSI-Only or IEOP).
Operational details for a Radiological Emergency can be found in, the County of Orange, San Onofre Nuclear Generating Station Emergency Operations Plan, January 2018.
August 2019 152
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Map 3.15: San Onofre Nuclear Generation Station Proximity Map
August 2019 153
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) Wild Fires General Background Fires can occur in urban environments and can also impact unpopulated areas that may contain brush or grasslands. The central, southern, and western portions of San Juan Capistrano are highly urbanized and relatively built out; however, the northern and eastern areas are approaching their build out potential. As a result, the City must continue to address the growing need to defend both persons and property from urban and wildland fires.
In urban areas, the effectiveness of fire protection efforts is based upon several factors, including the age of structures, efficiency of circulation routes that ultimately affect response times, and availability of water resources to combat fires. In wildland areas, taking the proper precautions, such as the use of fire resistant building materials, a pro-active Fire Prevention inspection program, and the development of defensible space around structures where combustible vegetation is controlled, can protect developed lands from fires and, therefore, reduce the potential loss of life and property.
Other factors contribute to the severity of fires including weather and winds. Specifically, winds commonly referred to as Santa Ana winds, which occur during fire season (typically from June to the first significant rain in November), are particularly significant. Such “fire weather” is characterized by several days of hot dry weather and high winds, resulting in low fuel moisture in vegetation. Definitions Interface Area - An area susceptible to wildfires and where wildland vegetation and urban or suburban development occur together. An example would be smaller urban areas and dispersed rural housing in forested areas.
Wildfire - Fires that result in uncontrolled destruction of forests, brush, field crops, grasslands, and real and personal property in nonurban areas. Because of their distance from firefighting resources, they can be difficult to contain and can cause a great deal of destruction. Wildland/Urban Interface Characteristics Certain conditions must be present for significant interface fires to occur. The most common conditions include: hot, dry, and windy weather; the inability of fire protection forces to contain or suppress the fire; the occurrence of multiple fires that overwhelm committed resources; and a large fuel load (dense vegetation). Once a fire has started, several conditions influence its behavior, including fuel topography, weather, drought, and development.
August 2019 154
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
There are three categories of wildland/urban interface:
The Classic Wildland/Urban Interface exists where well-defined urban and suburban development presses up against open expanses of wildland areas The Mixed Wildland/Urban Interface is characterized by isolated homes, subdivisions, and small communities situated predominantly in wildland settings The Occluded Wildland/Urban Interface exists where islands of wildland vegetation occur inside a largely urbanized area Wildfire Hazard Profile Community Wildfire Issues Wildland fires have occurred within Orange County, particularly in the fall of the year, ranging from small, localized fires to disastrous fires covering thousands of acres. The most severe fire protection problem in the unincorporated areas is wildland fires during Santa Ana wind conditions.
Reasons for control difficulty associated with wildland fires are:
Adverse weather conditions Large quantities of combustible fuel Inaccessible terrain Nonexistent or very limited water supply Large fire frontage requiring disbursement of fire forces
Due to its weather, topography, and native vegetation, the entire southern California area is at risk from wildland fires. The extended drought characteristics of California's Mediterranean climate result in large areas of dry vegetation that provide fuel for wildland fires. Furthermore, the native vegetation typically has a high oil content that makes it highly flammable. The area is also intermittently impacted by Santa Ana winds, the hot, dry winds that blow across southern California in the spring and late fall.
A wildland fire that consumes thousands of acres of vegetated property can overwhelm local emergency response resources. Often, when a wildland fire encroaches onto the built environment, multiple ignitions develop as a result of " branding", the term for wind transport of burning cinders over a distance of a mile or more. If ignited structures sustain and transmit the fire from one building to the next, a catastrophic fire can ensure.
One challenge Southern California faces regarding the wildfire hazard is from the increasing number of houses being built on the urban/wildland interface. Every year the growing population has expanded further and further into the hills and mountains, including forest lands. The increased "interface" between urban/suburban areas and the open spaces created by this expansion has produced a significant increase in threats to life and property from fires
August 2019 155
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
and has pushed existing fire protection systems beyond original or current design and capability. Factor Affecting Wildfires Fuel Fuel is the material that feeds a fire and is a key factor in wildfire behavior. Fuel is classified by volume and by type. Volume is described in terms of "fuel loading", or the amount of available vegetative fuel.
The type of fuel also influences wildfire. Chaparral is a primary fuel of Southern California wildfires. Chaparral habitat ranges in elevation from near sea level to over 5,000' in Southern California. Chaparral communities experience long dry summers and receive most of their annual precipitation from winter rains. Although chaparral is often considered as a single species, there are two distinct types: hard chaparral and soft chaparral. Within these two types are dozens of different plants, each with its own particular characteristics.
Fire has been important in the life cycle of chaparral communities for over 2 million years; however, the true nature of the "fire cycle" has been subject to interpretation. In a period of 750 years, it was generally thought that fire occurs once every 65 years in coastal drainages and once every 30 to 35 years inland.64
The vegetation of chaparral communities has evolved to a point where it requires fire to spawn regeneration. Many species invite fire through the production of plant materials with large surface-to-volume ratios, volatile oils, and through periodic die-back of vegetation. These species have further adapted to possess special reproductive mechanisms following fire. Several species produce vast quantities of seeds, which lie dormant until fire triggers germination. The parent plant, which produces these seeds, defends itself from fire by a thick layer of bark, which allows enough of the plant to survive so that the plant can crown sprout following the blaze. An important element in understanding the danger of wildfire is the availability of diverse fuels in the landscape, such as natural vegetation, manmade structures, and combustible materials. A house surrounded by brushy growth rather than cleared space allows for greater continuity of fuel and increases the fire's ability to spread. After decades of fire suppression, "dog-hair" thickets have accumulated, which enable high intensity fires to flare and spread rapidly.
64 California Coastal Commission, Natural History of Fire & Flood Cycles, Prepared by Jack Ainsworth & Troy Alan Doss as a presentation to the Post-Fire Hazard Assessment Planning and Mitigation Workshop at the University of California, Santa Barbara, August 18, 1995
August 2019 156
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Topography
Topography influences the movement of air, thereby directing a fire course. For example, if the percentage of uphill slope doubles, the rate of spread in wildfire will likely double. Gulches and canyons can funnel air and act as chimneys, which intensify fire behavior and cause the fire to spread faster.
Solar heating of dry, south-facing slopes produces up slope drafts that can complicate fire behavior. Unfortunately, hillsides with hazardous topographic characteristics are also desirable residential areas in many communities. This underscores the need for wildfire hazard mitigation and increased education and outreach to homeowners living in interface areas.
The San Juan Capistrano area encompasses grass and brush covered hillsides that facilitate the rapid spread of fire. In some portions of the City, there is significant topographic relief. The traffic in urban areas and long travel distances in rural hillside areas often hinder fire department response time. Weather Weather patterns combined with certain geographic locations can create a favorable climate for wildfire activity. Areas where annual precipitation is less than 30 inches per year are extremely fire susceptible. High-risk areas in Southern California share a hot, dry season in late summer and early fall when high temperatures and low humidity favor fire activity. The so-called "Santa Ana" winds, which are heated by compression as they flow down to Southern California from Utah, create a particularly high risk, as they can rapidly spread what might otherwise be a small fire.
The San Juan Capistrano area typically has mild winters that lead to an annual growth of grasses and plants. This vegetation dries out during the hot summer months and is exposed to Santa Ana wind conditions in the fall. Winds in excess of 40 miles per hour are typical; gusts in excess of 100 miles per hour may occur locally. In the San Juan Capistrano area, these winds tend to travel from north to south. However, when combined with winds generated from burning vegetation, wind direction is likely to be extremely erratic. Drought Recent concerns about the effects of climate change, particularly drought, are contributing to concerns about wildfire vulnerability. The term drought is applied to a period in which an unusual scarcity of rain causes a serious hydrological imbalance. Unusually dry winters, or significantly less rainfall than normal, can lead to relatively drier conditions and leave reservoirs and water tables lower. Drought leads to problems with irrigation and may contribute to additional fires, or additional difficulties in fighting fires.
August 2019 157
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Development Growth and development in scrubland and forested areas is increasing the number of human- made structures in Southern California interface areas. Wildfire has an effect on development, yet development can also influence wildfire. Owners often prefer homes that are private, have scenic views, are nestled in vegetation, and use natural materials. A private setting may be far from public roads or hidden behind a narrow, curving driveway. These conditions, however, make evacuation and fire fighting difficult. The scenic views found along mountain ridges can also mean areas of dangerous topography. Natural vegetation contributes to scenic beauty, but it may also provide a ready trail of fuel leading a fire directly to the combustible fuels of the home itself. Location and Extent of Wildfire Hazard Fire Hazard Severity Zones
CAL FIRE’s Fire and Resource Assessment Program has modeled and mapped wildfire hazard zones using a science-based and field-tested computer model that designates moderate, high, or very high fire hazard severity zones (FHSZ).
The FHSZ model is built from existing CAL FIRE data and hazard information based on factors such as the following: Fuel - Fuel may include living and dead vegetation on the ground, along the surface as brush and small trees, and above the ground in tree canopies. Lighter fuels such as grasses, leaves, and needles quickly expel moisture and burn rapidly, while heavier fuels such as tree branches, logs, and trunks take longer to warm and ignite. Trees killed or defoliated by forest insects and diseases are more susceptible to wildfire Weather - Relevant weather conditions include temperature, relative humidity, wind speed and direction, cloud cover, precipitation amount and duration, and the stability of the atmosphere. Of particular importance for wildfire activity are wind and thunderstorms: Strong, dry winds produce extreme fire conditions. Such winds generally reach peak velocities during the night and early morning hours. The thunderstorm season typically begins in June with wet storms and turns dry with little or no precipitation reaching the ground as the season progresses into July and August. Terrain - Topography includes slope and elevation. The topography of a region influences the amount and moisture of fuel; the impact of weather conditions such as temperature and wind; potential barriers to fire spread, such as highways and lakes; and elevation and slope of land forms (fire spreads more easily uphill than downhill).
The model is also based on frequency of fire weather, ignition patterns, and expected rate-of spread. It accounts for flying ember production, which is the principal driver of the wildfire hazard in densely developed areas. A related concern in built-out areas is the relative density of vegetative fuels that can serve as sites for new spot fires within the urban core and spread to adjacent structures.
August 2019 158
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
The model refines the zones to characterize fire exposure mechanisms that cause ignitions to structures. Map 3.16 shows the FHSZ mapping for San Juan Capistrano. Past Occurrences of Wildfires
Table 3.23: 20 Largest Wildfires in California since 1932 (when accurate records started to be kept)65 Name County Acres Start date Structures Deaths
Camp Butte 153,336 November 2018 18,804 86
Carr Shasta, Trinity 229,651 July 2018 1,604 8 Mendocino Mendocino, Lake, Colusa, Glenn 459,123 July 2018 280 1 Complex Thomas Ventura, Santa Barbara 281,893 December 2017 1,063 23 Rough Fresno 151,623 July 2015 4 0 Rim Tuolumne 257,314 August 2013 112 0
Rush Lassen 271,911 August 2012 1 0 Station Los Angeles 160,557 August 2009 209 2 Basin Complex Monterey 162,818 June 2008 58 0 Klamath Theater Siskiyou 192,038 June 2008 0 2 Complex Witch San Diego 197,990 October 2007 1,650 2 Zaca Santa Barbara 240,207 July 2007 1 0
Day Ventura 162,702 September 2006 11 0 Cedar San Diego 273,246 October 2003 2,820 15 McNally Tulare 150,696 July 2002 17 0 Big Bar Complex Trinity 140,948 August 1999 0 0 Stanislaus Tuolumne 145,980 August 1987 28 1 Complex Marble Cone Monterey 177,866 July 1977 0 0 Laguna San Diego 175,425 September 1970 382 5 Matilija Ventura 220,000 September 1932 0 0
65 California Department of Forestry and Fire Protection (CAL FIRE)
August 2019 159
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Table 3.24: Large Wildfires in Orange County66 Structures Fire Name Location Acres Year Lost
Green River Santa Ana Canyon 4.5 mi South of Corona 53,000+ 22 1948
Stewart Stewart Ranch Near San Juan Capistrano 69,440 20 1958
Paseo Grande Santa Ana Canyon Riverside/Orange County 51,00 46 1967
Laguna Laguna Canyon Road 14,437 448 1993
Santiago Santiago Canyon/Silverado Canyon 28,000 14 2007
Windy Ridge 241 Toll Road, South of SR91 2,000 3 2007
Freeway SR91 Near Green River Dr. 30,305 400 2008
241 142 Toll Road/Santiago Canyon Road 180 2 2015
Canyon 1 & 2 SR91 near Gypsum Canyon Road 9,217 25 2017
Holy Cleveland National Forest 23,136 18 2018
Table 3.25: Wildland Fires in or Near San Juan Capistrano 1979 to 2018 Fire Name Location Acres Year
Avery East of Trabuco Creek & North of Monarch Dr. 129.82 2002
Ridge Line West of Antonio Parkway & South of Crown Vallev 706.34 1994
Monarch East of Trabuco Creek & North of Monarch Dr. 101.40 1990
Ortega South of Ortega Hwy & East of La Pata 2,470.88 1988
Niguel South of Paseo De Colinas & West of 73 Hwy/5 Frwy 302.34 1979
The City of San Juan Capistrano is subject to both wildland and urban fires. The natural vegetation in the area is highly prone to wildland fire. A large portion of undeveloped land in the southeastern portion of the City is within a High Fire Hazard Area. The unincorporated land along the eastern
66 California Department of Forestry and Fire Protection (CAL FIRE)
August 2019 160
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
City limit and a portion of Mission Viejo located adjacent to the City of San Juan Capistrano's boundary are designated as Very High Fire Hazard Areas. These areas could create potential public safety hazards for the City's residents. Exiting Wildfire Mitigation Activities
The Orange County Fire Authority (OCFA) will actively enforce codes and ordinances to ensure a reasonable degree of fire safety exists in facilities and occupancies to minimize the threat to life and property. This activity is ongoing and conducted on a regular basis. Comprehensive pre-emergency planning, fire protection engineering, and training programs are currently in place and are designed to ensure the department's ability to meet future service demands. Probability of Future Occurrences Although San Juan Capistrano has not experienced a major wildland fire since 1979, many major wildfires in Orange County have been associated with adverse weather conditions. In addition to winds, structural development within or adjacent to wildland exposures represent an extreme fire protection problem due to flying embers and combustible roof coverings. There is a high probability of future occurrences. Potential Impacts A variety of fire protection challenges exist within or near the City, including urban fires, wildland fires, and fires in the urban/wildland interface. In critical fire weather, wildland fires burn with high intensity and high rates of spread. Moderate Santa Ana and onshore winds can be a threat to homes along ridgelines with a potential for heavier spotting and fire intensity along the San Juan Creek. Wildland Interface in San Juan Capistrano includes coastal hills with interface and intermix conditions. Critical Facilities
Two of the City’s fifty critical facilities are within a Very High Wildfire Severity Zone.
Table 3.26: San Juan Capistrano Critical Facilities Located in or Near (Very High) Severe Fire Hazard Zones Replacement Map # Facility Contents Value Potential Loss Value 26 Zone 3 #2 Reservoir (Lower Hunt Club) $420,454 $1,422,378 $1,842,832
27 Zone 3 #1 Reservoir (Upper Hunt Club) $0 $776,044 $776,044
Total Potential Losses $420,454 $2,198,422 $2,618,876
August 2019 161
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Twenty one of the fifty critical facilities are located in a High Wildfire Severity Zone.
Table 3.27: San Juan Capistrano Critical Facilities Located in or Near a High Severe Fire Hazard Zones Replacement Contents Potential Map # Facility Value Value Loss
15 JSerra Catholic High School * * * 16 San Juan Hills High School * * * 18 Reed Reservoir Zone 2 #1 $15,289 $2,827,748 $2,843,037 19 760 Reservoir South $7,184,567 $0 $7,184,567 20 Reed Reservoir Zone 2 #1B $15,289 $1,026,062 $1,041,351 21 Terminal Reservoir #2 na na na 22 Terminal Reservoir #3 $21,115,227 $0 $21,115,227 23 High West Side Reservoir #2 $95,560 $388,244 $483,804 24 High West Side Reservoir #1 $95,560 $323,611 $419,171 25 Cooks Reservoir $57,338 $0 $57,338 28 Mission Hills Reservoir na na na 35 North Open Space Well $0 $1,292,665 $1,292,665 36 Bear Brand (Aguacate) Pump Station $477,789 $1,292,843 $1,770,632 37 Bear Brand (Peppertree Bend) Pump Station $1,903,917 $0 $1,903,917 38 Capistrano Royale Pump Station $477,789 $1,292,843 $1,770,632 39 Captain's Hill Pump Station $477,789 $1,292,843 $1,770,632 40 Mission Hills Pump Station $477,789 $1,918,841 $2,396,630 41 Zone 2 Pump Station $783,573 $1,282,600 $2,066,173 42 Hidden Mountain Pump Station $477,789 $646,511 $1,124,300 43 Rosenbaum Well #1 $0 $1,292,665 $1,292,665 47 Rosenbaum Lift Station $0 $132,823 $132,823 Total Potential Losses $33,655,265 $15,010,299 $48,665,564 Replacement value information based on City insured values for each facility. * - Not City Owned na - No Data Available
August 2019 162
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Four of the fifty critical facilities are in a Moderately Wildfire Severity Zone.
Table 3.28: San Juan Capistrano Critical Facilities Located in or Near a Moderate Severe Fire Hazard Zones Replacement Contents Potential Map # Facility Value Value Loss 13 Mariners Church Ocean Hills * * *
45 Mission Street Well na na na
46 Strawberry Hill Pump Station na na na
50 SC-04 Flow Station $152,893 $996,160 $1,149,053
Total Potential Losses $152,893 $996,160 $1,149,053 Replacement value information based on City insured values for each facility. * - Not City Owned na - No Data Available
August 2019 163 City of San Juan Capistrano Local Hazard Mitigation Plan Map 3.16: Current Fire Hazard Severity Zones
Number Name Address Zone 26 Zone 3 #2 Reservoir (Lower Hunt Club) 30761 Steeplechase Drive Very High 27 Zone 3 #1 Reservoir (Upper Hunt Club) 30561 Steeplechase Drive Very High 15 JSerra Catholic High School 26351 Junipero Serra Road High 16 San Juan Hills High School 29211 Stallion Ridge High 18 Reed Reservoir Zone 2 #1 28422 Via Entrada High 19 760 Reservoir South 27271 Calle Delgado High 20 Reed Reservoir Zone 2 #1B 28422 Via Entrada High 21 Terminal Reservoir #2 27100 Highland Drive High 22 Terminal Reservoir #3 26861 Mission Hills Drive High 23 High West Side Reservoir #2 31572 Aguacate Road High 24 High West Side Reservoir #1 31572 Aguacate Road High 25 Cooks Reservoir 25702 Calle Ricardo High 28 Mission Hills Reservoir 21800 Highland Drive High 35 North Open Space Well 30291 Camino Capistrano High 36 Bear Brand (Aguacate) Pump Station 31672 Aguacate Road High 37 Bear Brand (Peppertree Bend) Pump Station 31546 Peppertree Bend High 38 Capistrano Royale Pump Station 26911 Highland Drive High 39 Captain's Hill Pump Station 25702 Windjammer Drive High 40 Mission Hills Pump Station 26902 Mission Hills Drive High 41 Zone 2 Pump Station 31232 Paseo Crucero High 42 Hidden Mountain Pump Station 31632 Via Cervantes High 43 Rosenbaum Well #1 29688 Rancho Viejo Road High 47 Rosenbaum Lift Station 29688 Rancho Viejo Road High 13 Mariners Church Ocean Hills 32222 Del Obispo Street Moderate 45 Mission Street Well 26601 Mission Street Moderate 46 Strawberry Hill Pump Station 31261 El Horno Street Moderate 50 SC-04 Flow Station Ortega Hwy & Antonio Pkwy Moderate
August 2019 164
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) Climate Change Considerations Human-caused warming has increased the area burned by wildfire in the Western United States, according to a 2017 report by the National Academy of Sciences, “particularly by drying forests and making them more susceptible to burning”.
A recent study cited by the report estimated that half as much forest area would have burned between 1984 and 2015 in a world not warmed by climate change.
Figure 3.7: In the West, Forest Fires Burn More Acres in a World Warmed by Climate Change67
Actual area burned
25 million acres 25 million acres
20 20
15 15
Cumulative acres burned 10 10
5 Estimated area 5 Estimated area burned without burned with climate change climate change
1985 1990 1995 2000 2005 2010 2015 1985 1990 1995 2000 2005 2010 2015
Source: Proceedings of the National Academy of Sciences; data updated through 2017 by A. Park Williams Vulnerability/Risk Assessment of Fire Hazards Due to adverse conditions such as drought, high temperatures, and seasonal Santa Ana winds, the City remains vulnerable to fire hazards.
67 Proceedings of the National Academy of Sciences; data updated through 2017 by A. Park Williams
August 2019 165
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) SUMMARY OF VULNERABILITY Table 3.29 shows a summary of critical facilities that intersect with hazard areas in the City of San Juan Capistrano. Those facilities that intersect with a hazard area are indicated with a “Y” and a blue-shaded cell. Facilities that do not fall within the hazard area are designated by an “N” and a yellow-shaded cell. The risks of drought, extreme heat, severe weather, and disease and pest management hazards are equal throughout the community.
Hazard and critical facilities overlays were not conducted for drought, extreme heat, epidemic and vector borne diseases, and severe weather. Overlays were conducted for seismic hazards (including liquefaction), floods, landslides, and transportation/ hazardous materials incidents. Significant Hazards
The vulnerability assessments in each hazard profile are used to understand the varying levels of risk to the City of San Juan Capistrano. Based on these assessments, the planning team concluded that the hazards that pose the greatest risk to the city are wildfire, seismic hazards, drought, and epidemic/pandemic/vector borne diseases.
Table 3.29: Risk Assessment Summary Table
Seismic
Hazards
Facility
Flood
Drought
(1,000 ft.) (1,000
Landslide Terrorism
yearflood Plain)
-
ExtremeHeat
SevereWeather
Liquefaction
Hazardous Materials
(100 RadiologicalHazards
WildlandFire Severity GroundShaking
1 City Hall Non-Wildland Fuel Yes Yes Yes No Yes Yes Yes Yes Yes Yes
2 Utilities Yard Non-Wildland Fuel Yes Yes Yes No Yes Yes Yes Yes Yes Yes
3 Dance Hall/Police Services Non-Wildland Fuel Yes Yes Yes No Yes Yes Yes Yes Yes Yes
4 Utilities Department Offices Non-Wildland Fuel Yes Yes Yes No Yes Yes Yes Yes Yes Yes
5 OCFA Fire Station #7 Non-Wildland Fuel Yes Yes No No Yes Yes Yes Yes Yes Yes SJC City Gym/Boys & Girls 6 Non-Wildland Fuel Yes Yes No No No Yes Yes Yes Yes Yes Club South Coast Christian 7 Non-Wildland Fuel Yes No No No No Yes Yes Yes Yes Yes Assembly Groundwater Recovery Plant 8 Non-Wildland Fuel Yes Yes Yes No Yes Yes Yes Yes Yes Yes (GWRP) 9 Public Works Yard Non-Wildland Fuel Yes Yes Yes No Yes Yes Yes Yes Yes Yes
August 2019 166
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Seismic
Hazards
Facility
Flood
Drought
(1,000 ft.) (1,000
Landslide Terrorism
yearflood Plain)
-
ExtremeHeat
SevereWeather
Liquefaction
Hazardous Materials
(100 RadiologicalHazards
WildlandFire Severity GroundShaking
10 Old Fire Station Complex Non-Wildland Fuel Yes Yes Yes No Yes Yes Yes Yes Yes Yes
11 SJC Community Center Non-Wildland Fuel Yes Yes No No No Yes Yes Yes Yes Yes San Juan Capistrano 12 Non-Wildland Fuel Yes Yes No No Yes Yes Yes Yes Yes Yes Regional Library 13 Mariners Church Ocean Hills Moderate Yes Yes No No Yes Yes Yes Yes Yes Yes
14 South Cooks Well Non-Wildland Fuel Yes Yes Yes No No Yes Yes Yes Yes Yes
15 JSerra Catholic High School High Yes Yes No No Yes Yes Yes Yes Yes Yes
16 San Juan Hills High School High Yes No No Yes No Yes Yes Yes Yes Yes St. Margaret's Episcopal 17 Non-Wildland Fuel Yes Yes Yes No No Yes Yes Yes Yes Yes School 18 Reed Reservoir Zone 2 #1 High Yes No No Yes No Yes Yes Yes Yes Yes
19 760 Reservoir South High Yes No No Yes No Yes Yes Yes Yes Yes
20 Reed Reservoir Zone 2 #1B High Yes No No Yes No Yes Yes Yes Yes Yes
21 Terminal Reservoir #2 High Yes No No Yes No Yes Yes Yes Yes Yes
22 Terminal Reservoir #3 High Yes No No Yes No Yes Yes Yes Yes Yes
23 High West Side Reservoir #2 High Yes No No Yes No Yes Yes Yes Yes Yes
24 High West Side Reservoir #1 High Yes No No Yes No Yes Yes Yes Yes Yes
25 Cooks Reservoir High Yes No No No No Yes Yes Yes Yes Yes Zone 3 #2 Reservoir 26 Very High Yes No No Yes No Yes Yes Yes Yes Yes (Lower Hunt Club) Zone 3 #1 Reservoir 27 Very High Yes No No Yes No Yes Yes Yes Yes Yes (Upper Hunt Club) 28 Mission Hills Reservoir High Yes No No Yes No Yes Yes Yes Yes Yes
29 CVWD Well #1 Non-Wildland Fuel Yes Yes No No Yes Yes Yes Yes Yes Yes
30 SJBA Well #2 Non-Wildland Fuel Yes Yes No No No Yes Yes Yes Yes Yes
August 2019 167
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Seismic
Hazards
Facility
Flood
Drought
(1,000 ft.) (1,000
Landslide Terrorism
yearflood Plain)
-
ExtremeHeat
SevereWeather
Liquefaction
Hazardous Materials
(100 RadiologicalHazards
WildlandFire Severity GroundShaking
31 Tirador Well Non-Wildland Fuel Yes Yes Yes No No Yes Yes Yes Yes Yes
32 Kinoshita Well Non-Wildland Fuel Yes Yes No No Yes Yes Yes Yes Yes Yes
33 Well #5A Non-Wildland Fuel Yes Yes Yes No No Yes Yes Yes Yes Yes
34 SJBA Well #4 Non-Wildland Fuel Yes Yes No No Yes Yes Yes Yes Yes Yes
35 North Open Space Well High Yes Yes No No Yes Yes Yes Yes Yes Yes Bear Brand (Aguacate) 36 High Yes No No No No Yes Yes Yes Yes Yes Pump Station Bear Brand (Peppertree 37 High Yes No No No No Yes Yes Yes Yes Yes Bend) Pump Station Capistrano Royale Pump 38 High Yes No No Yes No Yes Yes Yes Yes Yes Station 39 Captain's Hill Pump Station High Yes No No No No Yes Yes Yes Yes Yes
40 Mission Hills Pump Station High Yes No No Yes No Yes Yes Yes Yes Yes
41 Zone 2 Pump Station High Yes No No No No Yes Yes Yes Yes Yes Hidden Mountain Pump 42 High Yes No No Yes No Yes Yes Yes Yes Yes Station 43 Rosenbaum Well #1 High Yes Yes No No Yes Yes Yes Yes Yes Yes
44 Dance Hall Well Non-Wildland Fuel Yes Yes Yes No Yes Yes Yes Yes Yes Yes
45 Mission Street Well Moderate Yes Yes No No Yes Yes Yes Yes Yes Yes
46 Strawberry Hill Pump Station Moderate Yes Yes Yes No No Yes Yes Yes Yes Yes
47 Rosenbaum Lift Station High Yes Yes Yes No Yes Yes Yes Yes Yes Yes
48 Master Meter CM10 ETM Non-Wildland Fuel Yes Yes No No Yes Yes Yes Yes Yes Yes
49 Tricities Interconnect Non-Wildland Fuel Yes No No No Yes Yes Yes Yes Yes Yes
50 SC-04 Flow Station Moderate Yes Yes No No No Yes Yes Yes Yes Yes
August 2019 168
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Potential Losses
Table 3.30 identifies the critical facilities with the greatest total value (combination of building replacement and contents value) in the City. Should these facilities be completely destroyed by a hazard event, their replacement will be the costliest compared to other identified critical facilities.
Table 3.30: Most Costly Critical Facilities Total Replacement Content Map# Facility (Replacement and Value Value Contents) Value*
1 City Hall $6,000,000 $3,000,000 $9,000,000
2 Utilities Yard $859,760 $667,666 $1,527,426
3 Dance Hall/Police Services $675,137 $37,859 $712,996
4 Utilities Department Offices $505,150 $867,709 $1,372,859
6 SJC City Gym/Boys & Girls Club $4,374,080 $10,000 $4,384,080
8 Groundwater Recovery Plant (GWRP) $27,042,929 $0 $27,042,929
9 Public Works Yard $525,574 $822,313 $1,347,887
10 Old Fire Station Complex $3,208,197 $34,364 $3,242,561
11 SJC Community Center $7,367,194 $440,523 $7,807,717
12 San Juan Capistrano Regional Library $7,800,083 $50,000 $7,850,083
18 Reed Reservoir Zone 2 #1 $15,289 $2,827,748 $2,843,037
19 760 Reservoir South $7,184,567 $0 $7,184,567
20 Reed Reservoir Zone 2 #1B $15,289 $1,026,062 $1,041,351
22 Terminal Reservoir #3 $21,115,227 $0 $21,115,227
23 High West Side Reservoir #2 $95,560 $388,244 $483,804
24 High West Side Reservoir #1 $95,560 $323,611 $419,171
25 Cooks Reservoir $57,338 $0 $57,338
26 Zone 3 #2 Reservoir (Lower Hunt Club) $420,454 $1,422,378 $1,842,832
27 Zone 3 #1 Reservoir (Upper Hunt Club) $0 $776,044 $776,044
35 North Open Space Well $0 $1,292,665 $1,292,665
36 Bear Brand (Aguacate) Pump Station $477,789 $1,292,843 $1,770,632
August 2019 169
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
37 Bear Brand (Peppertree Bend) Pump $1,903,917 $0 $1,903,917 Station 38 Capistrano Royale Pump Station $477,789 $1,292,843 $1,770,632
39 Captain's Hill Pump Station $477,789 $1,292,843 $1,770,632
40 Mission Hills Pump Station $477,789 $1,918,841 $2,396,630
41 Zone 2 Pump Station $783,573 $1,282,600 $2,066,173
42 Hidden Mountain Pump Station $477,789 $646,511 $1,124,300
43 Rosenbaum Well #1 $0 $1,292,665 $1,292,665
47 Rosenbaum Lift Station $0 $132,823 $132,823
50 SC-04 Flow Station $152,893 $996,160 $1,149,053
Total Potential Losses $92,586,716 $24,135,315 $116,722,031 Replacement value information based on City insured values for each facility.
Vulnerability/Risk Assessment Method
The risk assessment prepared for this plan is based solely on the facilities listed in Table 2.11 that are under the City’s control. The City did not conduct a risk assessment or potential losses for critical facilities that are outside of the City’s control.
The LHMP Team identified replacement and contents values for a majority of the facilities based on the City’s insured values; these represent the total loss values for each facility. If a facility is completely destroyed in a hazard event, the replacement and contents values indicate the cost to replace the facility. Depending on the year the facility was built, the cost to repair a damaged facility may be more than the replacement value. While replacement and content values are used throughout this plan to estimate potential losses, it is noted that the actual cost to recover from a hazard will depend on the type and magnitude of the event.
The critical facilities listed in Table 2.11 were mapped in GIS and overlaid with mapped hazard areas to determine which assets are located within each hazard area. Hazard area and critical facility overlays were conducted for seismic hazards (liquefaction), flood, transportation/hazardous materials, landslides, and wildfire. Hazard and critical facility overlays were not conducted for drought, terrorism, radiological hazards, severe weather, or epidemic and vector borne diseases. These hazards affect the entire city and therefore all facilities listed in the critical facility inventory could be potentially susceptible to damage from them.
Replacement and contents values for the facilities that fall within the hazard areas are tallied in each vulnerability table to estimate the total potential losses to each facility. It should be noted that the actual losses will depend on the type and extent of the hazard event.
August 2019 170
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) HAZARD PRIORITIZATION The LHMP Team used a Microsoft Excel-based tool to prioritize the identified hazards by assigning each hazard a ranking based on probability of occurrence and potential impact. These rankings were assigned based on group discussion, knowledge of past occurrences, and familiarity with the City’s infrastructure vulnerabilities. Four criteria were used to establish priority:
Probability (likelihood of occurrence) Affected Area (size of potentially affected area) Primary Impacts (intensity of damage) Secondary Impacts (severity of impacts to community)
A value of 1 - 4 was assigned for each criterion. The four criteria were then weighted based on the LHMP Team’s opinion of each criterion’s importance.
Table 3.31 describes the scoring method for each of the criteria listed above and the process for calculating a total score used to determine the planning consideration level.
August 2019 171
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Table 3.31: Hazard Ranking Worksheet Legend Probability Based on estimated likelihood of occurrence from historical data Score Unlikely Less than 1% probability in next 100 years or has a recurrence interval of greater than every 100 years. 1 Somewhat Likely Between 1 and 10% probability in next year or has a recurrence interval of 11 to 100 years. 2 Likely Between 10 and 100% probability in next year or has a recurrence interval of 10 years or less. 3 Highly Likely Near 100% probability in next year or happens every year. 4 Importance =X 2.0 Affected Area Based on size of geographical area of community affected by hazard Score Isolated 1 Small 2 Medium 3 Large 4 Importance =X 0.8 Primary Impacts Based on percentage of damage to typical facility in community Score Negligible - less than 10% damage 1 Limited - between 10% and 25% damage 2 Critical - between 25% and 50% damage 3 Catastrophic - more than 50% damage 4 Importance =X 0.7 Secondary Impacts Based on estimated secondary impacts to community at large Score Negligible - no loss of function, downtime, and/or evacuations 1 Limited - minimal loss of function, downtime, and/or evacuations 2 Moderate - some loss of function, downtime, and/or evacuations 3 High - major loss of function, downtime, and/or evacuations 4 Importance =X 0.5 Total Score = Probability x Impact, where: Probability = (Probability Score x Importance) Impact = (Affected Area + Primary Impact + Secondary Impacts), where: Affected Area = Affected Area Score x Importance Primary Impact = Primary Impact Score x Importance Secondary Impacts = Secondary Impacts Score x Importance
Hazard Planning Consideration Total Score (Range) Hazard Level 0.0 12.0 Low 12.1 42.0 Medium 42.1 64.0 High
August 2019 172
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Notes: The probability of each hazard is determined by assigning a level, from unlikely to highly likely, based on the likelihood of occurrence from historical data. The total impact value includes the affected area, primary impact, and secondary impact levels of each hazard. Each level's score is reflected in the matrix. The total score for each hazard is the probability score multiplied by its importance factor times the sum of the impact level scores multiplied by their importance factors. Based on this total score, the hazards are separated into three categories based on the hazard level they pose to the communities: High, Medium, and Low.
Based on a ranking exercise with the LHMP Team and follow-up discussion with City staff, the following identified hazards were confirmed and corresponding planning considerations levels established for this Plan as listed in Table 3.31 and Table 3.32.
Table 3.32: Hazard Ranking Analysis Performed by the San Juan Capistrano LHMP Team on 2/26/19 Impact
Probability Total Score Hazard Type Affected Primary Secondary Area Impact Impact Sum of Factored Hazard Planning Consideration Impacts (Sum of Factored Score Factored Score Factored Score Factored Score Factored Impacts) x x 2.0 x .8 x .7 x .5 (Factored Probability)
Medium Medium Drought 3 6 4 3.2 2 1.4 1 0.5 5.1 30.6
Medium Medium Landslide Hazards 3 6 2 1.6 2 1.4 2 1 4 24 Radiological 1 2 1 0.8 1 0.7 3 1.5 3 6 Low Accidents
Medium Wildfire 3 6 3 2.4 3 2.1 3 1.5 6 36
Medium Medium Flood Hazards 3 6 2 1.4 2 2.8 2 2 4 24
Seismic Hazards 2 4 4 3.2 4 2.8 4 2 8 32 Medium Medium
Severe Weather 3 6 2 1.6 1 0.7 1 0.5 2.8 16.8 Medium Medium Epidemic/Pandemic/ Vector Borne 2 4 4 3.2 2 1.4 3 1.5 6.1 24.4 Medium Medium Diseases Transportation/Haza 3 6 1 0.8 1 0.7 2 1 2.5 15 Medium Medium rdous Materials
Low Terrorism 1 2 1 0.8 3 2.1 4 2 4.9 9.8
August 2019 173
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Table 3.33: Ranking of Hazards by the San Juan Capistrano LHMP Team on 2/26/19 Hazard Planning Rank Hazard Score Consideration 1 Wildfire 36.0 Medium 2 Seismic Hazards 32.0 Medium 3 Drought 30.6 Medium 4 Epidemic/Pandemic/Vector Borne Diseases 24.4 Medium 5 Flood Hazards 24.0 Medium 6 Landslide Hazards 24.0 Medium 7 Severe Weather 16.8 Medium 8 Transportation/Hazardous Materials Incidents 15.0 Medium 9 Terrorism 9.8 Low 10 Radiological Accidents 6 Low
August 2019 174
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) CHAPTER 4: HAZARD MITIGATION STRATIGY OVERVIEW San Juan Capistrano’s hazard mitigation strategy is to develop and implement a comprehensive set of actions that are intended to reduce the impacts of hazard events. These hazard mitigation actions will help to protect the safety of residents, visitors, critical facilities, vital services, the local economy, and other important community assets. Hazard mitigation actions are derived from an in-depth review of the vulnerabilities and capabilities described in this Plan. Overall, the mitigation actions described in this Plan represent San Juan Capistrano’s risk-based approach for reducing and/or eliminating the potential losses as identified in Chapter 3: Hazard Assessments.
This section provides information on the process used to develop goals and action items aimed at reducing the impact of several natural hazards on the City of San Juan Capistrano. The action items were developed after an in-depth review of the City’s vulnerabilities and capabilities as described in Chapters 3 and 4.
The mitigation actions presented here are organized by implementation timing as follows:
Actions that are already being implemented on an on-going basis Actions that the City wants to implement in the next five (5) years
This organization takes into account the City’s priorities and the realities of funding and personnel availability. The mitigation actions are also classified by the hazard that they address, with action items that address two or more hazards at the same time referred to as multi-hazard action items. GOALS AND OBJECTIVES OF HAZARD MITIGATION Hazard mitigation plans must identify goals for reducing long-term vulnerabilities to identified hazards (44 CFRSection 201.6(c)(3)(i)). The LHMP Team and City staff established a set of goals and objectives for this plan, based on data from the preliminary risk assessment and the results of the public involvement strategy.
The goals, objectives, and actions in this plan all support each other. Objectives were selected that met multiple goals. Actions were prioritized based on the action meeting multiple objectives.
Goal #1 - Protect Life and Property Objectives: Implement activities that assist in protecting lives by making homes, businesses, infrastructure, critical facilities, and other property more resistant to natural hazards Reduce losses and repetitive damages from chronic (frequently recurring) hazard events while promoting insurance coverage for catastrophic hazards Improve hazard assessment information from which to make recommendations to discourage new development and encourage preventive measures for existing development in areas particularly vulnerable to natural hazards
August 2019 175
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Goal #2 - Increase Public Awareness Objectives: Develop and implement educational and outreach programs that increase public awareness of the risks associated with natural hazards Keep the public informed of natural hazard mitigation initiatives and activities through local newspapers, the local access channel, the City’s website, newsletters, utility bill inserts, and other similar media Provide information on tools, partnership opportunities, and funding resources that can help in the implementation of mitigation activities
Goal #3 – Improve Natural Systems Objectives: Balance the need to protect and manage the natural resources and areas in the City (such as open space, creeks, watershed, etc.) with the need for hazard mitigation to protect lives and property in the developed areas, to reduce any conflict that may arise between these two objectives. Whenever possible, preserve, rehabilitate, and enhance the natural systems in ways that also provide natural hazard mitigation functions
Goal #4 – Develop Partnerships in Implementation Objectives: Strengthen communication and coordinate participation among and within City departments, other agencies, citizens, non-profit organizations, businesses, and industries so that there is a mutual, vested interest in the implementation of the action items. Encourage leadership within public and private sector organizations to prioritize and implement local, county, and regional hazard mitigation activities
Goal #5 – Enhance Emergency Services and Response Objectives: Establish procedures to ensure that mitigation projects strengthen critical and essential facilities, services, and infrastructure, where needed, and are considered and prioritized Coordinate and integrate natural hazard mitigation activities, where appropriate, with emergency operations, plans, and procedures Strengthen emergency operations by increasing collaboration and coordination among public agencies, non-profit organizations, businesses, and industries
August 2019 176
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) HAZARD/THREAT ASSESSMENT The LHMP Team relied in part on the hazard profiles and threat assessments in this Plan to develop the actions in the mitigation strategy. A set of mitigation actions were prepared that respond to the relevant hazard situations and provide protection to residents, businesses, and community assets in San Juan Capistrano. Care was taken to ensure that the mitigation actions will help to reduce damage from the most frequent types of hazard events, the most significant that may reasonably occur, and those with the greatest potential to harm the community. CAPABILITIES ASSESSMENT The LHMP Team and City staff performed a capabilities assessment to review the existing local agencies, public policies, funding sources, individuals, and other resources that can support hazard mitigation activities in San Juan Capistrano. The hazard mitigation actions build off of the existing success of these resources and leverage their capabilities to support improved resiliency in the community.
The capabilities assessment looked at the following types of resources:
Personnel Resources: City staff and volunteers, and staff and volunteers at other agencies Plan Resource: Advisory or enforceable plans adopted by the City or other agencies Policy Resource: Policies adopted and implemented by the City or other agencies Technical Resource: Data and tools available to the City
Table 4.1: Resource Assessment Resource Type of Ability to Support Mitigation Website Name Resource
Local
The San Juan Capistrano Building Code and associated standards (Residential Code, Mechanical Code, Electrical Code, etc.) are a set of regulations that govern how new buildings are constructed. These http://qcode.us/ standards are published by the state and are adopted by local codes/sanjuan Building Code Policy communities, sometimes with amendments to make the codes more capistrano/?vie Resource locally applicable. Mitigation actions to construct buildings to a safer w=desktop standard, allowing them to better resist damage during a hazard event, may be made part of future building code updates.
The San Juan Capistrano Capital Improvement Projects is a set of construction projects planned for City-owned buildings, facilities, http://sanjuanc and infrastructure. It is updated every year as part of the City’s apistrano.org/D Capital epartments/Pu Plan annual budget and includes projects for the next 10 years. Improvement blic- Resource Mitigation actions to retrofit existing City-owned structures or to Plan Works/Capital- build new ones that are better able to resist damage may be Improvement- implemented by including these projects in the Capital Improvement Projects Plan in the future.
August 2019 177
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Resource Type of Ability to Support Mitigation Website Name Resource
The Community Services Department is responsible for the development and delivery of the comprehensive leisure/human services including community enrichment programs. The Department oversees public and group use of many City facilities including the Community Center, City Gymnasium, Sports Park, other athletic field parks, Historic Town Center Park, Los Rios Park, Community Gardens, La Sala Auditorium and Courtyard, City rental park sites, and one of the City’s newest parks, Reata Park and Event Center. The Department publishes a quarterly community newsletter and http://sanjuanc Community apistrano.org/D Personnel maintains the Community Services Department’s web pages on the Services epartments/Co Resource City website, which provides important program and services Department mmunity- information. The Department also provides staff support to the: Services Parks, Recreation, Senior and Youth Services Commission; Trails and Equestrian Commission; Youth Advisory Board; Boys & Girls Clubs of Capistrano Valley; San Juan Capistrano Fiesta Association; San Juan Senior Citizens Club, Inc.; Age Well Senior Services; community youth/adult sport organizations; and various active community-based service groups. Mitigation actions related to education and community outreach may be implemented through Community Services Staff.
The San Juan Capistrano Development Services Department provides information and advisory services to decision makers and the public regarding the growth and development of the community to ensure balanced physical development. The Development Services Department is responsible for approving building permits, ensuring http://sanjuanc Development that buildings and private property comply with appropriate standards, apistrano.org/D Personnel Services and conducting short-term and long-term planning activities in the epartments/De Resource Department community. As part of these duties, the department enforces the San velopment- Juan Capistrano Building Code and all land use regulations. Services Mitigation actions related to the construction of new structures or retrofits or improvements to existing structures may be implemented through future plan processing by Development Services Department staff.
The City of San Juan Capistrano Community Emergency Response Team (CERT) program is designed to increase individual and http://sanjuanc Community community preparedness and self-reliance in the event of man-made apistrano.org/D Emergency Personnel epartments/Em or natural disasters. CERT volunteers are trained in emergency Response Resource ergency- procedures and are duly registered as Disaster Service Workers in Team Preparedness/ accordance with the California Government Code and the City of San CERT Juan Capistrano Municipal Code.
August 2019 178
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Resource Type of Ability to Support Mitigation Website Name Resource
The City of San Juan Capistrano maintains a comprehensive Emergency Management Program that includes all elements http://sanjuanc necessary to respond to major emergencies. City employees are apistrano.org/D Emergency trained in the National Incident Management System, which provides a Personnel epartments/Em Preparedness proactive approach to guide departments and agencies at all levels of Resource ergency- Program government, nongovernmental organizations, and the private sector to work together seamlessly and manage incidents involving all threats Preparedness and hazards—regardless of cause, size, location, or complexity—in order to reduce loss of life, property, and harm to the environment.
The Finance Department supports the other departments of the City and the City’s residents by providing critical financial information regarding the City’s operations and programs. Key functions of the Finance Department that are encompassed within that objective are http://sanjuanc Finance maintaining the financial records of the City, coordinating the budget Personnel process, monitoring budgetary compliance, processing all purchase apistrano.org/D Department Resource and payment transactions, and the receipting, depositing, and epartments/Fin investing of all City funds. In addition, the Finance Department is the ance point of contact for the customer service needs of the public that pertain to business licenses, parking permits, film and photography permits, and utility service billing and payment inquiries.
The Orange County Fire Authority (OCFA) provides fire protection and firefighting services in San Juan Capistrano. The department’s responsibilities include taking preparatory steps to prevent fires or Fire and limit their destruction. OCFA also provides fire protection and Personnel https://www.ocf Rescue firefighting services to the unincorporated areas of Orange County Resource a.org/ Services and many other incorporated communities. Fire-related mitigation actions related to reducing the likelihood of fires or minimizing injury and damage from fires may be implemented through fire department staff.
The San Juan Capistrano General Plan is the long-term, http://sanjuanc comprehensive blueprint for development and changes in the apistrano.org/D community. The policies in the general plan address land uses, epartments/De Plan public safety, environmental protection, transportation, and others. velopment- General Plan Resource The general plan serves as a framework for mitigation actions, Services/Planni establishing the overarching policies for mitigation activities. ng- Mitigation actions may be directly incorporated into the general plan Zoning/General to provide a stronger enforcement mechanism. -Plan
San Juan Capistrano Human Resources is a department of the City Manager’s Office. Human Resources implements and maintains a central personnel system for the City, providing guidance and http://sanjuanc Human support to all departments for recruitment, selection, apistrano.org/D Personnel Resources classification/salary structures, employee benefits, employee epartments/Hu Resource Division relations, employee training, labor negotiations, performance man- evaluation, employee development, and other personnel programs Resources and processes. Mitigation actions that relate to staff training may be implemented through the Human Resources Division.
August 2019 179
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Resource Type of Ability to Support Mitigation Website Name Resource
The Orange County Sheriff’s Department (OCSD) is responsible for maintaining public safety in the community. As part of this work, the police department is responsible for conducting crime prevention http://www.oc Police Personnel activities, investigating criminal activity, and directing traffic. sd.org/patrol/ Services Resource Mitigation actions that relate to the safe movement of traffic (e.g. sjcapistrano during evacuations), the public safety of residents during emergency events, and terrorism-related activities may be implemented through Sheriff’s Department staff.
The San Juan Capistrano Public Works Department is responsible for the operations and maintenance of public streets, multi-modal trails, parks and sports fields, buildings and facilities, landscape districts, and the City’s fleet vehicles and equipment. The Public http://sanjuan Public Works Works Department is also responsible for weed and debris capistrano.or Personnel and Utilities abatement and graffiti removal from public lands, streets, and g/Department Resource Department facilities. Internal support services are provided during special s/Public- events, various emergencies, and to Police Services. Mitigation Works actions that involve constructing or retrofitting City-owned facilities and infrastructure may be implemented through Public Works Department staff.
The Division provides for domestic water service, recycled water Public Works http://sanjuan Personnel service, wastewater collection service, and stormwater collection capistrano.or and Utilities Resource throughout the City. The Department also oversees the solid waste g/Department Department collection services provided by the City’s franchise hauler. s/Utilities
Mandatory Although the drought state of emergency has been eliminated, http://sanjuanc apistrano.org/D Restrictions on Policy permanent restrictions prohibiting wasteful water practices remain in epartments/Util Resource Water Waste place as per San Juan Capistrano Municipal Code Title 6, Chapter ities/Water- Ordinance 12.05. Conservation
The San Juan Capistrano Municipal Code is an implementation tool for the City’s general plan. It establishes regulations for land uses throughout the community, including where different types of Zoning development and land use activity can occur, how these http://www.qc Policy ode.us/codes/ Districts and developments can look, and how they may be operated. Mitigation Resource sanjuancapist Standards actions that relate to the siting, construction, and operation of new rano/ developments in San Juan Capistrano may be implemented through Title 9, Chapter 3 of the Municipal Code to ensure these locations address risks identified in the plan.
The Orange County General Plan is the long-term blueprint for growth and development in the unincorporated areas of Orange Orange http://www.ocp County, including the hills surrounding San Juan Capistrano. ublicworks.com County Plan Mitigation actions that require coordination with the county may be /ds/planning/ge General Plan Resource supported by including these actions in the Orange County General neralplan Plan.
August 2019 180
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Resource Type of Ability to Support Mitigation Website Name Resource
The County of Orange and Orange County Fire Authority Local Hazard Mitigation Plan 2015 identifies and describes the hazard events that may occur in the unincorporated areas of Orange County, http://cams.ocg and provides a suite of mitigation actions to help decrease the ov.com/Web_P ublisher/Agend Orange potential damage from these hazards. Mitigation actions for San Juan Plan a07_12_2016_ County Hazard Capistrano that require coordination with the county may be Resource files/images/O0 Mitigation Plan integrated into the County’s Hazard Mitigation Plan. Similar mitigation 0216- actions in both the County’s and San Juan Capistrano’s hazard 000668A.PDF mitigation plans can lead to a more regionally unified hazard mitigation strategy, which may improve effectiveness.
Regional, State, and Federal Agencies
Cal-Adapt is an online tool that provides detailed projections for future climate-related conditions in California, including factors such as temperature, precipitation, and sea level rise. These projections Technical https://cal- Cal-Adapt can help inform forecasts of future hazard events and can explain Resource adapt.org/ how hazard conditions are expected to change. The Committee can use Cal-Adapt to monitor anticipated changes in future climate conditions and adjust mitigation actions accordingly.
The California Department of Transportation (Caltrans) is the state California agency with jurisdiction over designated highways, including Technical http://www.caltr Department of Interstate 5 (I-5) and Ortega Highway (State Route 74). Mitigation Resource ans.ca.gov/ Transportation measures related to ensuring the resiliency of state-designated freeways will be implemented through coordination with Caltrans.
The California Governor’s Office of Emergency Services (Cal OES) is the state agency responsible for reducing hazards in the state through mitigation activities, conducting emergency planning, California supporting emergency response and recovery activities, and acting Governor’s Technical as a liaison between local and federal agencies on emergency- https://www.cal Office of Resource related issues. It provides guidance on hazard mitigation planning oes.ca.gov/ Emergency activities, shares best practices, and distributes funding Services opportunities. The Committee can work with Cal OES to obtain funding to implement LHMP mitigation strategies and to receive guidance on future updates.
August 2019 181
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Resource Type of Ability to Support Mitigation Website Name Resource
The California State Hazard Mitigation Plan assesses the types of https://www.cal hazards that may be present in California. It includes descriptions of oes.ca.gov/cal- these hazards, summaries of past hazard events, descriptions of how oes- California these hazards may occur in the future, and how these hazards may divisions/hazar State Hazard Plan d- harm the people and assets of California. Like a local hazard Mitigation Resource mitigation/haza mitigation plan, the State Hazard Mitigation Plan is updated every Plan rd-mitigation- five years. The Committee can use the State Hazard Mitigation Plan planning/state- as a source of information to refine the hazard profiles and hazard- vulnerability assessments in future San Juan Capistrano LHMPs. mitigation-plan
The Federal Emergency Management Agency (FEMA) is the federal agency responsible for hazard mitigation, emergency preparedness, Federal and emergency response and recovery activities. It provides Emergency Technical https://www.fe guidance to state and local governments on hazard mitigation Management Resource ma.gov/ activities, including best practices and how to comply with federal Agency requirements. FEMA also provides funding for hazard mitigation actions through grant programs.
Private Agencies
San Diego The San Diego Gas & Electric Company (SDG&E) is the electrical Gas & Technical service provider for San Juan Capistrano. Mitigation actions that https://www.sd Electric Resource relate to the resiliency of San Juan Capistrano’s electrical grid will be ge.com/ Company implemented through coordination with SDG&E.
The Southern California Gas Company (SoCalGas) is the natural Southern gas provider for San Juan Capistrano and also owns the natural California Technical gas infrastructure in the community. Mitigation actions that address https://www.so Gas Resource the resiliency of natural gas infrastructure and services in San calgas.com/ Company Juan Capistrano will be implemented through coordination with SoCalGas.
AT&T is the phone company providing service in San Juan Technical https://www.att. AT&T Capistrano. Mitigation actions that address the resiliency of the Resource com/ telephone network will be implemented and coordinated with AT&T.
Cox Communications is the cable, internet, and telecommunications Cox https://www.co Technical provider in San Juan Capistrano. Mitigation actions that address the x.com/residenti Communicati Resource resiliency of the cable, internet, and telecommunications network will al/myconnectio ons be implemented and coordinated with Cox Communications. n/home.html
August 2019 182
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) MITIGATION ACTIONS
Hazard mitigation actions are activities that City departments, other organizations, businesses, and residents can implement to reduce risk. Each action item includes an estimate of the time line for implementation. Short-term action items are activities that City departments may implement with existing resources and authorities within the next five years or sooner. Short-term action items also include activities that, although the resources to implement them are not readily available, are considered priorities that need to be implemented within this updated cycle (that is, in the next five years). Long-term action items are considered less of a priority, and because they may require new or additional resources or authorities, they are not likely to be implemented within the next five years but may be implemented in years six through ten.
There are also several mitigation activities that the LHMP Team and City Staff have identified from the 2004 LHMP that are conducted on an on-going basis. These activities are also listed in this document, as they are an important component in the City’s efforts to reduce its vulnerability to natural disasters. Evaluation of Potential Hazard Mitigation Actions
The LHMP Team prepared a set of potential mitigation actions based on the hazard profiles, threat assessments, capabilities assessments, results of the community survey, discussions among team members, and existing best practices.
FEMA requires local governments to evaluate the monetary and nonmonetary costs and benefits of potential mitigation actions. Although local governments are not required to assign specific dollar values to each action, they should identify the general size of costs and benefits. The local government may elect to include measures that have a high cost or low benefits, but such measures should be clearly beneficial to the community and an appropriate use of local resources.
In addition, FEMA directs local governments to consider the following questions as part of the financial analysis:
What is the frequency and severity of the hazard type to be addressed by the action, and how vulnerable is the community to this hazard? What impacts of the hazard will the action reduce or avoid? What benefits will the action provide to the community? What critical facilities, if any, will benefit from the action? How many facilities will benefit, and how important are they to the community? What are the environmental benefits or impacts of the action? STAPLE/E Process
The City staff chose to review and revise the potential hazard mitigation actions using a set of criteria known as STAPLE/E (Social, Technical, Administrative, Political, Legal, Economic, and Environmental). The Committee did not formally assess every potential mitigation action under all
August 2019 183
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
STAPLE/E criteria but used the criteria to guide and inform discussion. The team also discussed how these criteria may be used to evaluate grant applications the City may submit to receive funding for LHMP implementation. Table 4.2 describes the criteria and grading scale for each impact in the cost benefit analysis.
Table 4.2: STAPLE/E Grading Scale Category Impact Description and Grading Scale for Each Impact
Is the action perceived as socially acceptable to a wide segment of the population? 0 = public indifferent to action Acceptance 1 = somewhat popular 2 = popular 3 = very popular Social Is the action item likely to impact (positively or negatively) a particular segment of the Effect on population? Segment of -3 = will negatively impact a segment of the population Population 0 = will have no effect 3 = will have a very positive effect on a segment of the population.
Is the action feasible given our current knowledge or science? 0 = no Feasibility 1 = somewhat 2 = moderately 3 = absolutely Technical Is implementation of this action going to reduce the hazard permanently? Long- 0 = no Term 1 = slightly Solution 2 = somewhat 3 = yes
Is there staff currently at the City doing this work? Does it involve 1 person or more? 3 = yes, several, enough to get the work done 2 = yes, 2 or more but not enough to do the proposed work 1 = yes, 1 person Staffing 0 = no -1 = City needs to hire someone to do the work -2 = City needs to hire 2 people to do the work -3 = City needs to hire several people to get this done
Administrative 0 = no funding currently allocated Funding 1 = some funding allocated, need a lot more $ Allocated 2 = funding available, enough to do the basics 3 = funding available to do the work without cutting corners
Does this action require constant maintenance and upgrade? 0 = no, this is a one-time expenditure -1= some minor maintenance required Maintenance -2 = constant maintenance by 1 individual required -3 = constant maintenance and upgrade required, effort requires 2 or more individuals assigned to task.
August 2019 184
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Category Impact Description and Grading Scale for Each Impact
Is the action going to be popular with the public? -3 = very unpopular Public Support 0 = no public reaction, indifferent 3 = very popular Political Is the action going to be popular with the Mayor and City Council? Political -3 = very unpopular Support 0 = no reaction, indifferent 3 = very popular
Is there a State mandate or a recommendation to have this done? 0 = no State Authority 1 = there is minor State interest in doing this 2 = there is a strong support at the State level to do this 3 = there is a State mandate to do this, generally with a target date for implementation
Is there a local mandate or recommendation to implement this action? 0 = no Legal Local Authority 1 = there is minor local support to get this done 2 = there is strong local support to get this done 3 = there is a City mandate to get this done
Is this action likely to get challenged in court? Possible legal 0 = no -1 = a small possibility action? -2 = yes, some people might object enough to go to court -3 = yes, expect several neighbors to challenge this in court
The economic benefits of implementing this action. 0 = no benefit Benefit 1= small benefit 2= benefit 3 = great benefit
The economic costs of implementing this action 0 = no costs Economic Cost -1 = small cost -2 = some cost -3= very expensive
Is there outside funding available to implement this action? 0 = no Outside Funding 1 = small amounts of money, not enough to get it done 2 = funding available 3 = enough money available to get this done
Does this action have a positive or negative impact on the environment? Impacts on -3 = severe negative impact on environment Environment 0 = no impact 3 = very positive impact on environment. Environmental Consistent with Is the proposed action consistent with the City's environmental goals? Community's -3 = goes against all goals to protect the environment Environmental 0 = has no impact on the local environmental goals Goals 3 = is very consistent with the City’s environmental goals
August 2019 185
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) Mitigation Action Items
The hazard mitigation actions are activities that San Juan Capistrano will utilize to reduce its risk to potential hazards. The Mitigation Action Items presented in this updated Local Hazard Mitigation Plan were developed during LHMP Team meetings, public workshops, community feedback, and documentation review. Based on the criteria and evaluation processes used during the development of the plan, the Team prepared a prioritized list of Mitigation Action Items to improve San Juan Capistrano’s resiliency to hazard events. The mitigation actions are intended to address risk reduction in a range of identified hazards; therefore, some actions address multiple hazards. Some of these mitigation actions may be eligible for funding through federal and state grant programs, and other funding sources as made available to the City. Coordinating Department, Agency, or Organization
The coordinating organization is the organization that is willing and able to organize resources, find appropriate funding, or oversee activity implementation, monitoring, and evaluation. Coordinating organizations may include local, City, regional agencies or departments, and private entities that are capable of or responsible for implementing activities and programs. Potential Funding Sources
Most action items require funding for item such as, but not limited to; personnel, equipment, supplies, property, structures, etc. Potential funding sources are identified as a starting point to fully funding an action item initiative. Constraints
Constraints to the immediate implementation of the action items are typical, usually because of limited resources, as described further below. Constraints may include a lack of City staff to do the work, lack of funds, or vested property rights that might expose the City to legal action as a result of adverse impacts on private property. Timeline
Action items include both short- and long-term activities. Each action item includes an estimate of the timeline for implementation. Plan Goals Addressed
The Plan goals addressed by each action item are included as a way to monitor and evaluate how well the Hazards Mitigation Plan is achieving its goals once implementation begins.
August 2019 186
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) Ongoing Mitigation Action Items
Table 4.3 lists the Mitigation Action Items identified from the 2004 LHMP document that the City performs on an ongoing basis and will continue to implement in the 2019 LHMP.
Table 4.3: Ongoing Mitigation Action Items Coordinating Potential Department, Plan Goals Ongoing Mitigation Actions Funding Constraints Agency, or Addressed Source(s) Organization
Multi Hazard
Development General Personnel Develop 1. Integrate the goals and action Services Fund Partnerships items from the City’s Local Hazard Mitigation Plan into existing Planning regulatory documents and programs, where appropriate. Development Advisory Board (DAB): Ideas For Implementation - Public Works - Building Department A. Institutionalize guidelines for - OCFA sustainable development in all new construction and development projects according to the hazards that impact the City of San Juan Capistrano.
B. Integrate the City's Local Hazard Mitigation Plan into current capital improvement plans to ensure that development does not encroach on known hazard areas.
C. Partner with other organizations and agencies with similar goals to promote Building & Safety Codes that are more disaster resistant at the state and local level.
August 2019 187
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Coordinating Potential Department, Plan Goals Ongoing Mitigation Actions Funding Constraints Agency, or Addressed Source(s) Organization
Multi Hazard
2. Identify and pursue funding LHMP General Personnel Develop opportunities to develop and Committee Fund Partnerships implement City mitigation activities.
Ideas For Implementation
A. Develop incentives for local governments, citizens, and businesses to pursue hazard mitigation projects.
Multi Hazard
3. Establish a formal role for the City LHMP General Personnel Develop of San Juan Capistrano Local Committee Fund Partnerships Hazard Mitigation Committee to develop a sustainable process for implementing, monitoring, and evaluating citywide mitigation activities.
Ideas For Implementation
A. Establish clear roles for participants, meeting regularly to pursue and evaluate implementation of mitigation strategies.
B. Establish a meeting schedule to evaluate mitigation policies, new updates, and programs to provide recommendations for updating and revising the Local Hazard Mitigation Plan.
C. Conduct a full review and approval by Cal OES and FEMA of the Local Hazards Mitigation Action Plan every 5 years by evaluating mitigation successes, failures, and areas that were not addressed.
August 2019 188
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Coordinating Potential Department, Plan Goals Ongoing Mitigation Actions Funding Constraints Agency, or Addressed Source(s) Organization
Multi Hazard
4. Develop inventories of at-risk Development General Personnel Protect Life buildings and infrastructure and Advisory Board Fund and Property prioritize mitigation projects. (DAB): - Public Works Hazard Develop Ideas For Implementation - Building Mitigation Partnerships Department Grants OCFA A. Develop strategies to mitigate risk to - critical facilities, and identify alternative facilities should natural hazards damage the facilities in question.
B. Identify bridges at risk from flood or earthquake hazards, identify mitigation actions, and implement projects as funds become available.
Multi Hazard
5. Strengthen emergency services Building Grant Funding Enhance preparedness and response by Department Funding Emergency linking emergency services with Personnel Services/ natural hazard mitigation programs Public Works Response and enhancing public education on a regional scale.
Ideas For Implementation
A. Educate private property owners on limitations of bridges and dangers associated with them.
B. Develop a process to encourage private property owners to upgrade their bridges to support weight of fire trucks and emergency vehicles.
C. Encourage individual and family preparedness through public education projects such as safety fairs.
August 2019 189
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Coordinating Potential Department, Plan Goals Ongoing Mitigation Actions Funding Constraints Agency, or Addressed Source(s) Organization
D. Coordinate the maintenance of emergency transportation routes through communication among the Department of Public Works, Department of Transportation, neighboring jurisdictions, and the California Department of Transportation.
E. Identify opportunities for partnering with citizens, private contractors, and other jurisdictions to increase availability of equipment and manpower for efficiency of response efforts.
F. Work with Community Planning Organizations (CPO's) and other neighborhood groups to establish community emergency response teams.
G. Familiarize public officials of requirements regarding public assistance for disaster response.
Flood
6. Analyze each repetitive flood Development General Personnel Protect Life property within the City of San Advisory Board Fund and Property Juan Capistrano and identify (DAB): Funding feasible mitigation options. - Public Works Grant Develop - Building Funding Partnerships Ideas For Implementation Department - OCFA A. Identify appropriate and feasible mitigation activities for identified repetitive flood properties. Research FEMA’s Hazard Mitigation Grant and Flood Mitigation Assistance Programs and the Pre-disaster Mitigation Program for potential funding.
August 2019 190
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Coordinating Potential Department, Plan Goals Ongoing Mitigation Actions Funding Constraints Agency, or Addressed Source(s) Organization
B. Contact repetitive loss property owners to discuss mitigation opportunities and determine interest should future project opportunities arise.
C. Explore options for incentives to encourage property owners to engage in mitigation.
Flood
7. Enhance data and mapping for Public Works / General Personnel Protect Life floodplain information within the GIS Fund and Property City and identify and map flood- prone areas outside of designated Grant floodplains. Funding
Ideas For Implementation
A. Apply for FEMA's cooperative technical partnership using the 2-foot contour interval floodplain mapping data acquired by the City of San Juan Capistrano GIS.
B. Use WES inventory and mapping data to update the flood-loss estimates for the City of San Juan Capistrano.
C. Encourage the development of floodplain maps for all local streams not currently mapped on Flood Insurance Rate Maps or county maps, with special attention focused on mapping rural and unincorporated areas. The maps should show the expected frequency of flooding, the level of flooding, and the areas subject to inundation. The maps can be used for planning, risk analysis, and emergency management.
August 2019 191
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Coordinating Potential Department, Plan Goals Ongoing Mitigation Actions Funding Constraints Agency, or Addressed Source(s) Organization
Landslide
8. Encourage construction and Development General Personnel Increase subdivision design that can be Advisory Board Fund Public applied to steep slopes to reduce (DAB): Awareness the potential adverse impacts from Public Works development. Building Department OCFA Ideas For Implementation
A. Increase communication and coordination between the City's Departments.
Landslide
9. Review local ordinances regarding Development General Personnel Protect Life building and development in Services / Fund and Property landslide prone areas. Planning Building Ideas For Implementation Department
Public Works A. Create committee of local stakeholders to study issues and make recommendations to staff.
Wildfire
10. Enhance emergency services to OCFA Fire Act Funding Enhance increase the efficiency of wildfire Grants Emergency response and recovery activities. Volunteer Personnel Services Organizations
Ideas For Implementation
A. Continue to develop Fire Watch programs and increase reporting stations/communications equipment (such as additional fire reporting phone lines) for better access and coverage.
August 2019 192
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Coordinating Potential Department, Plan Goals Ongoing Mitigation Actions Funding Constraints Agency, or Addressed Source(s) Organization
B. Continue to develop and increase response training and educational outreach programs.
C. Enhance internal and external notification systems that include all at- risk urban/wildland interface residents in the jurisdiction in order to contact them during evacuations.
Wildfire
OCFA Fire Funding Protect Life 11. Encourage development and Prevention and Property dissemination of maps relating to Grants the fire hazard to help educate and Development Personnel assist builders and homeowners in Services / Increase being engaged in wildfire Planning Public mitigation activities and to help Awareness guide emergency services during Emergency response. Management
Building Ideas For Implementation Department
Public Works A. Update wildland/urban interface maps. GIS
B. Conduct risk analysis incorporating data and the created hazard maps using GIS technology to identify risk sites and further assist in prioritizing mitigation activities.
C. Encourage coordination between fire jurisdictions and sanitary districts to make sure that the most accurate elevation maps are being used.
August 2019 193
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Coordinating Potential Department, Plan Goals Ongoing Mitigation Actions Funding Constraints Agency, or Addressed Source(s) Organization
Wildfire
12. Enhance outreach and education OCFA Fire Funding Protect Life programs aimed at mitigating Prevention and Property wildfire hazards and reducing or Grants Personnel preventing the exposure of Increase citizens, public agencies, private Insurance Public property owners, and businesses Grants Awareness to natural hazards.
Ideas For Implementation
A. Continue the hiring of fire prevention and education personnel to oversee education programs.
B. Continue to train in all areas of fire prevention.
C. Visit urban interface neighborhoods and rural areas and conduct education and outreach activities.
D. Conduct specific community-based demonstration projects of fire prevention and mitigation in the urban interface.
E. Establish neighborhood "drive- through" activities that pinpoint site- specific mitigation activities. Fire crews can give property owners personal suggestions and assistance.
F. Perform public outreach and information activities at fire stations by creating "Wildfire Awareness Week" activities. Fire stations can hold open houses and allow the public to visit, see the equipment, and discuss wildfire mitigation with the station crews.
August 2019 194
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Coordinating Potential Department, Plan Goals Ongoing Mitigation Actions Funding Constraints Agency, or Addressed Source(s) Organization
Wildfire
13. Increase communication, OCFA Fire Funding Protect Life coordination, and collaboration Prevention and Property between wildland/urban interface Grants property owners, local and county Increase planners, fire prevention crews, Public and officials to address risks, Awareness existing mitigation measures, and federal assistance programs. Develop Partnerships Ideas For Implementation Enhance Emergency A. Encourage single-family residences to Services have fire plans and practice evacuation routes.
B. Encourage fire inspections in residential homes by fire departments to increase awareness among homeowners and potential fire responders.
C. Encourage a standard for the State Fire Marshal to evaluate fire plans and emergency plans.
D. Require fire department notification of new business applications to ensure that appropriate fire plans have been developed.
E. Encourage local zoning and planning entities to work closely with landowners and/or developers who choose to build in the wildland/urban interface to identify and mitigate conditions that aggravate wildland/urban interface wildfire hazards, including:
Limited access for emergency equipment due to width and grade of roadways
August 2019 195
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Coordinating Potential Department, Plan Goals Ongoing Mitigation Actions Funding Constraints Agency, or Addressed Source(s) Organization
Inadequate water supplies and the spacing, consistency, and species of vegetation around structures
Inadequate fuel breaks, or lack of defensible space and highly flammable construction materials
Building lots and subdivisions that are not in compliance with state and local land use and fire protection regulations
Inadequate entry/escape routes
Encourage all new homes and major remodels involving roof additions that are located in the interface to have fire resistant roofs and residential sprinkler systems
Encourage the public to evaluate access routes to rural homes for firefighting vehicles and to develop passable routes
August 2019 196
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) New Mitigation Action Items
New Mitigation Action Items were prioritized by taking the average score for each item from SAPLE/E worksheets completed by members of the LHMP team, and ranking the priority based on the average score from highest to lowest.
Table 4.4 lists the new Mitigation Action Items selected by the LHMP Team as well as the prioritization of each action and other details related to implementation.
Table 4.4: New Mitigation Action Items Responsible Potential Department, Time Plan Goals New Mitigation Actions Funding Constraints Agency, or Frame Addressed Source(s) Committee
Multi Hazard
1. Protect the City’s critical Utilities Mitigation Funding 4 yrs. Protect Life and water supply from Grants Property contamination and tampering.
Ideas For Implementation
A. Replace the roofs on the Lower and Upper Hunt Club Reservoirs.
Earthquake
2. Take measures to protect the City’s water supply in Utilities Mitigation Funding 5 yrs. Protect Life and event of an earthquake by Grants Property installing protective equipment on each of the Enhance City’s 10 reservoirs. Emergency Services/ Ideas For Implementation Response
A. Install flex ball couplings at the inlet and outlet of the City’s 10 reservoirs.
B. Install earthquake triggered, remotely controlled, isolation valves on the City’s 10 reservoirs.
August 2019 197
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Responsible Potential Department, Time Plan Goals New Mitigation Actions Funding Constraints Agency, or Frame Addressed Source(s) Committee
Multi Hazard
3. Encourage public Emergency EM Grants Personnel 2 yrs. Protect Life and participation in alert and Management Property warning systems. Enhance Ideas For Implementation Emergency Services/ Response A. Provide speakers to make presentations to community groups on the need to participate in the systems.
B. Send sign-up information to residents in their utility bills.
Terrorism
4. Provide increased security Public Mitigation Funding 5 yrs. Protect Life and for City owned critical Works Grants Property facilities. Enhance Emergency Ideas For Implementation Services/ Response A. Increase funding for citywide
surveillance for terrorist- related threats.
B. Create a city-wide surveillance system using remote detection and video monitoring to protect critical infrastructure such as water treatment facilities, reservoirs, wells, and pump stations.
August 2019 198
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Responsible Potential Department, Time Plan Goals New Mitigation Actions Funding Constraints Agency, or Frame Addressed Source(s) Committee
Flood
5. Explore the relocation of City Hazard Funding 5 yrs. Protect Life and City Hall, Police Services, Manager’s Mitigation Property and Public Works facilities Office Grant Personnel out of the 100- year flood Enhance plain. Development Emergency Services / Services/ Ideas For Implementation Planning Response
Building A. Create an exploratory Department committee to identify and evaluate potential land use Public Works options.
B. Begin the process of developing a grant application.
Multi Hazard
6. Explore the removal of Public Works Mitigation Funding 5 yrs. Protect Life and overhead power Grants Property distribution lines in favor Edison of underground Enhance infrastructure. SDG&E Emergency Services/Respon se Ideas For Implementation Increase Public Awareness
A. Form an exploratory committee to gather data and gauge public support.
B. Pursue grant funding from multiple sources to support feasibility studies.
August 2019 199
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
Responsible Potential Department, Time Plan Goals New Mitigation Actions Funding Constraints Agency, or Frame Addressed Source(s) Committee
Multi Hazard
7. Increase the volume Utilities Mitigation Funding 5 yrs. Protect Life and capacity of each of the Grants Property High West Side Reservoirs to increase Enhance fire flow capability in Emergency those areas of the city. Services/ Response Ideas For Implementation
A.
Multi Hazard
8. Analyze existing City Public Works Mitigation Funding and 2 yrs. Protect Life and owned open space and Grants Personnel Property trails for use as fire roads OCFA and fire breaks. Enhance Emergency Services/ Ideas For Implementation Response
A. Coordinate with OCFA to Increase Public study the usefulness of Awareness creating fire breaks along city owned open space.
Flood
9. Create a movable flood Utilities Mitigation Funding 4 Yrs. Protect Life and hardened perimeter and Grants Property sump pump system around the City’s Ground Water Recovery Plant.
Ideas For Implementation
A. Evaluate various methods, materials, and vendors.
August 2019 200
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT) FEMA NATIONAL FLOOD INSURANCE PROGRAM The City of San Juan Capistrano has designated a Floodplain Administrator who regulates land use through the San Juan Capistrano Municipal Code, Title 8: Building Regulations; Chapter 11: Floodplain Management was adopted by Ordinance No. 627 on May 3, 1988 and amended by Ordinance 1067 on May 7, 2019. Construction of any kind is not permitted in the Special Flood Hazard Area without first obtaining approval by the City Public Works Department. A Grading Permit is required to ensure that development is in compliance with the City Ordinance and the National Flood Insurance Program (NFIP). Making improvements within the Special Flood Hazard Area without proper consideration of flood flow and flood mitigation could potentially result in loss of life and property. Proper review and permitting ensure that cuts and fills, landscaping, new improvements, and any other man-made changes do not obstruct flood flows that consequently result in flooding of properties outside of the floodplain.
Most of the City’s government buildings are located in the floodplain and include the following: City Hall, Utilities Department Trailer, Utilities Warehouse, Utilities Field Office and Maintenance Yard, Police Services, Public Works Maintenance Building, and the Ground Water Treatment Plant.
Repetitive Loss Properties
At this time, the City of San Juan Capistrano is not aware of any Repetitive Loss Properties under the NFIP. Community Rating System
The Community Rating System (CRS) is an NFIP program that recognizes and encourages community floodplain management activities that exceed the minimum NFIP standards. Depending upon the level of participation, flood insurance premium rates for policyholders can be reduced up to 45%. CRS ratings are on a 10-point scale (from 10 to 1, with 1 being the best rating), with residents of the community who live within FEMA’s Special Flood Hazard Areas (SFHA) receiving a 5 percent reduction in flood insurance rates for every Class improvement in the community’s CRS rating.
Besides the benefit of reduced insurance rates, CRS floodplain management activities enhance public safety, reduce damages to property and public infrastructure, avoid economic disruption and losses, reduce human suffering, and protect the environment. Participating in the CRS provides an incentive to maintaining and improving a community's floodplain management program over the years. Implementing some CRS activities can help projects qualify for certain other Federal assistance programs.
August 2019 201
City of San Juan Capistrano Local Hazard Mitigation Plan (DRAFT)
The City of San Juan Capistrano participates in the CRS and has a CRS Ranking of 8, which means that residents with the SFHA receive a 10% discount on their flood insurance rates, and residents in non- SFHA areas that purchase flood insurance can receive a 5% discount.68
RELATIONSHIP TO OTHER CITY PLANS Senate Bill 1241
At the State level, and to address the increasing losses associated with wildfires at the wildland urban interface, Senate Bill 1241 (2012 Kehoe Statutes) requires that cities revising their Housing Element of the General Plan on or after January 1, 2014 review and update their Safety Element to address the risk of fire in State Responsibility Areas and in very high fire hazard severity zones. The City of San Juan Capistrano will update the Fire Hazards section of the Safety Element to comply with this requirement, utilizing the data presented in this Plan. Assembly Bill 2140
AB 2140 provides a financial incentive for local agencies to adopt a Local Hazard Mitigation Plan as a component of the Safety Element of their General Plan. The City of San Juan Capistrano adopted its 2004 Hazard Mitigation Plan (adopted in 2007) and linked it, by reference, to the Safety Element of their General Plan (Adopted January 21, 2014/Revised September 19, 2017). This 2019 Update will be treated similarly, recognizing that sections of the Safety Element need to be updated to comply with the requirements of Senate Bill 1241, as discussed above.
68 fema.gov/media-library-data/
August 2019 202