2025 County of Los Angeles All-Hazards Mitigation PlanChief Executive %SœJN - %SœJN of Emergency Management
County of Los AngelesAll-Hazards Mitigation Plan
AcknowledgementThe Los Angeles County Board of Supervisors gratefully acknowledges the following agencies/jurisdictions who contributed to the development of this plan. County DepartmentsAging and DisabilitiesUVNSxNJqpVvN%SœJNUVNS1qmpAV_AIV]Vpy%SœJNBeaches and HarborsEconomic Opportunity Health ServicesHuman ResourcesParks and Recreation Public HealthPublic Social ServicesPublic WorksRegional PlanningFire (LACoFD)Internal ServicesSheriff (LASD) Disaster Management Area Coordinators State of CaliforniaA]VSal_VAavNl_al¯m%SœJNaS^NlTN_Jy1NlvVJNmA]%1 California State Council on Developmental Disabilities (SCCD)External PartnersAccess ServicesAlzheimer’s AssociationCatholic CharitiesCity of Beverly Hills City of Long BeachDisability Community Resource CenterEastern Los Angeles Regional CenterEmergency Network Los AngelesHabitat for Humanity Harbor Regional Center Lanterman Regional Center!am_TN]Nmaq_py%SœJNaSLqJApVa_Los Angeles County Sanitation DistrictsLos Angeles County Metropolitan Transportation AuthorityLos Angeles Regional Food BankNeighborhood Legal Services of Los Angeles CountyPuente Hills Habitat Preservation Authority South Central Los Angeles Regional CenterWestside Regional Center Cover Photo Credits: !am_TN]Nmaq_pyUVNSxNJqpVvN%SœJNaq_pywVLNa^^q_VJApVa_m lA_JU
Los Angeles County Department of Public Works
County of Los Angeles
All-Hazards Mitigation Plan
Table of Contents Acknowledgement ................................................................................................................. 1Letter of Promulgation ........................................................................................................... 21 _plaLqJpVa_-qliamNA_L1JaiN ................................................................................ 6
1.1 Purpose ...................................................................................................................... 7
1.2 Scope ......................................................................................................................... 7
1.3 Legal Authority and Requirements ......................................................................... 71.4 Plan Organization ..................................................................................................... 8 2 Planning Process ............................................................................................................. 9
2.1 Overview of the Planning Process ........................................................................ 102.2 Stakeholder Engagement ...................................................................................... 132.3 Public Involvement and Outreach ........................................................................ 182.4 Review and Incorporation of Existing Plans and Reports .................................. 19 3 a^^q_Vpy-laœ]N ........................................................................................................ 22
3.1 Los Angeles County Overview .............................................................................. 233.2 Geography and Land Use ..................................................................................... 243.3 Social Vulnerability ................................................................................................. 253.4 Economy and Critical Infrastructure ..................................................................... 283.5 Climate and Environmental Conditions ............................................................... 293.6 Regional Collaboration and Planning Efforts ...................................................... 303.7 Implications for Hazard Mitigation Planning ....................................................... 31 4 Climate Change ............................................................................................................ 32
4.1 Climate Change Overview .................................................................................... 334.2 _pNTlApV_T]V^ApNUA_TNV_paA|AlL-laœ]Nm ............................................... 344.3 Climate Mitigation Strategies ................................................................................ 364.4 Climate Change Conclusion ................................................................................. 37 County of Los Angeles
All-Hazards Mitigation Plan
5 Integrating Access and Functional Needs (AFN) into Hazard Mitigation .............. 38
5.1 AFN Introduction .................................................................................................... 395.2 Inclusion of AFN and Vulnerable Populations in Planning ................................ 395.3 Assessment of AFN Needs .................................................................................... 405.4 Coordination with AFN Support Agencies .......................................................... 425.5 AFN Conclusion ...................................................................................................... 42 6 A|AlLLN_pVœJApVa_A_L0Vm\mmNmm^N_p ............................................................... 43
6.1 A|AlLLN_pVœJApVa_%vNlvVNw ............................................................................. 446.2 :V]LœlN ..................................................................................................................... 496.3 Earthquake .............................................................................................................. 576.4 Extreme Heat ........................................................................................................... 676.5 Drought .................................................................................................................... 746.6 Flooding .................................................................................................................. 826.7 Dam Failure ............................................................................................................. 926.8 Land Movement .................................................................................................... 1026.9 Tsunami .................................................................................................................. 1146.10 Severe Wind and Tornado ............................................................................... 1206.11 Mass Violence .................................................................................................... 1306.12 Cybersecurity Incidents .................................................................................... 1356.13 Transportation Incidents ................................................................................... 1426.14 Public Health Emergencies .............................................................................. 147 7 Mitigation Strategy ...................................................................................................... 152
7.1 Mitigation Strategy Overview .............................................................................. 1537.2 Mitigation Goals and Objectives ........................................................................ 1537.3 Existing Mitigation Capabilities .......................................................................... 155
7.4 LN_pVœJApVa_A_L_A]ymVmaS"VpVTApVa_1plApNTVNm ......................................... 172 County of Los Angeles All-Hazards Mitigation Plan
7.5 Status of Previous Mitigation Efforts ................................................................... 1847.6 Prioritization and Implementation of Mitigation Actions ................................. 1867.7 Integration with Other Plans ............................................................................... 1897.8 Mitigation Action Plan .......................................................................................... 191 8 Plan Maintenance ........................................................................................................ 196
8.1 Community Participation in Plan Maintenance ................................................. 1978.2 "a_VpalV_TvA]qApVa_A_L"AV_pN_A_JN......................................................... 1988.3 Criteria for Updating the Hazard Mitigation Plan ............................................. 1998.4 Plan Update ........................................................................................................... 2008.5 Integration with Other Plans ............................................................................... 201 9 Plan Adoption .............................................................................................................. 202
9.1 Plan Adoption Overview ...................................................................................... 203 Appendices ......................................................................................................................... 204 County of Los Angeles
All-Hazards Mitigation Plan
1 _plaLqJpVa_-qliamN
and Scope
County of Los Angeles All-Hazards Mitigation Plan
1.1 Purpose The 2025 All-Hazard Mitigation Plan (AHMP) was developed in collaboration with a wide range of stakeholders representing County Departments and other external mpA\NUa]LNlm Sla^ JVpVNm ]aJA] qpV]VpVNm _a_-TavNl_^N_pA] alTA_V|ApVa_m A_L mpApNagencies. The purpose of this AHMP is to form the strategic-level foundation for hazard mitigation efforts undertaken by the County of Los Angeles. The 2025 AHMP is an update to the 2020 version of the plan and seeks to maintain the County’s continuing commitment to hA|AlL^VpVTApVa_ Am A JlVpVJA] mpNi V_ lNLqJV_T UA|AlL lVm\m^A\V_TJa^^q_VpVNmmASNlA_LIqV]LV_TJaq_pywVLNlNmV]VN_JN1.2 Scope A|AlL^VpVTApVa_VmLNœ_NLV_pUNaLNaSNLNlA]0NTq]ApVa_m0 Am¬A_ymqmpAV_NLaction taken to reduce or eliminate the long-term risk to human life and property from UA|AlLm3UVm"-VLN_pVœNmA_Lilaœ]NmUA|AlLmA_A]y|NmpUNiNai]NA_LJlVtical V_SlAmplqJpqlNAplVm\A_LilavVLNmAmNlVNmaS^VpVTApVa_mplApNTVNmAV^NLAplNLqJV_Thazard risk. The plan also describes actions to integrate vulnerable communities including people with Access and Functional Needs (AFN) into hazard mitigation planning and other efforts. The AHMP is intended to function as a strategic plan for UA|AlL^VpVTApVa_ A_LwUV]N_ap A_N^NlTN_Jyi]A_ Ja^i]N^N_pm pUN !am_TN]NmCounty Operational Area Emergency Operations Plan. This plan contains mitigation strategies for County-owned facilities or other areas under the jurisdiction of the County of Los Angeles. Hazard mitigation strategies for incorporated cities within Los Angeles County may be found in that city’s hazard mitigation plan. 1.3 Legal Authority and Requirements Historically local hazard mitigation planning has been driven by federal law. The Disaster Mitigation Act (DMA) of 2000 amended the Robert T. Stafford Disaster Relief and Emergency Assistance Act of 1988 with new requirements for hazard mitigation. The DMA aSN^iUAmV|NL pUN_NNLSalmpApN plVIA]A_L]aJA]N_pVpVNm pa J]amN]ycoordinate on hazard mitigation efforts and formed the legal basis for the Federal Emergency Management Agency’s (FEMA) current mitigation plan requirements in order to utilize Hazard Mitigation Assistance grant programs. This plan was prepared County of Los Angeles
All-Hazards Mitigation Plan
pursuant to the requirements set forth in the DMA of 2000 and other FEMA hazard mitigation policy guidance. 1.4 Plan Organization The AHMP is organized into nine (9) mNJpVa_mNxJ]qLV_TpUNiiN_LVJNm including:
1. Introduction: VmJqmmNmpUNiqliamNmJaiNA_L]NTA]AqpUalVpyaSpUNi]A_
2. Planning Process: Describes the planning process that was undertaken by the Hazard Mitigation Planning Committee to create this updated 2025 AHMP.
3. a^^q_Vpy-laœ]N %vNlvVNwmpUNq_VkqNTNaTlAiUVJJ]V^ApVJN_vVla_^N_pA] and socioeconomic factors that make up Los Angeles County and their implications for hazard mitigation planning.
4. Climate Change: Outlines the impacts of climate change in Los Angeles County and potential mitigation and adaptation measures.
5. Integrating AFN into Hazard Mitigation: Discusses strategies for integrating people with Access and Functional Needs (AFN) into prevention and hazard mitigation efforts.
6. A|AlL LN_pVœJApVa_ A_L 0Vm\ mmNmm^N_p LN_pVœNm A_L ilaœ]Nm nine (9) natural and four (4) human-caused hazards that may impact Los Angeles County including: wV]LœlN NAlpUkqA\N NxplN^N UNAp LlaqTUp ŔaaLV_T LA^ SAV]qlN]A_L^avN^N_ppmq_A^VmNvNlNwV_LA_Lpal_ALa^AmmvVa]N_JNJyINlmNJqlVpyV_JVLN_pmplA_mialpApVa_V_JVLN_pmA_LiqI]VJUNA]pUN^NlTN_JVNm
7. Mitigation Strategy: Delineates the overall strategy for the County’s hazard ^VpVTApVa_NSSalpmV_J]qLV_TTaA]mA_LaI[NJpVvNmNxVmpV_T^VpVTApVa_JAiAIV]VpVNmand an analysis of mitigation actions.
8. Plan Maintenance: Outlines how the plan will be maintained annually ahead of pUN_NxpSq]]i]A_qiLApNV_œvNyNAlm
9. Plan Adoption: Discusses updates to the plan and implementation following plan adoption.
a]]awV_T pUNmNmNJpVa_m pUNlN AlN A_ ALLVpVa_A]six (6) appendices with supporting ^ApNlVA]m mqJU Am UA|AlL ^Aim ^NNpV_T ^V_qpNm Sla^ i]A__V_T ^NNpV_Tm A_Linformation about the public engagement efforts during the planning process.
County of Los Angeles All-Hazards Mitigation Plan
2 Planning Process
County of Los Angeles
All-Hazards Mitigation Plan
2.1 Overview of the Planning ProcessThe 2025 Los Angeles County All-Hazard Mitigation Plan (AHMP) update builds upon the robust all-hazard planning framework established by the 2020 All-Hazards "VpVTApVa_ -]A_ wUV]N V_JalialApV_T _Nw ^NpUaLa]aTVNm mpA\NUa]LNl N_TATN^N_pand compliance requirements. The planning process for this update emphasized V_J]qmVvVpy plA_miAlN_Jy A_L pUN V_pNTlApVa_ aS N^NlTV_T J]V^ApN ALAipApVa_considerations. 3UVm i]A__V_T ilaJNmmSa]]awNL A mplqJpqlNL iUAmNL AiilaAJU A]VT_NL wVpU "¯m!aJA] "VpVTApVa_ -]A__V_T -a]VJy qVLN 0 lNkqVlN^N_pm A_L TqVLA_JNSla^pUNA]VSal_VAavNl_al¯m%SœJNaS^NlTN_Jy1NlvVJNmA]%1 3UVmAiilaAJUbegan witUila[NJpV_VpVApVa_wUNlNpUNmJaiNpV^N]V_NA_LmpA\NUa]LNlmwNlNLNœ_NLStakeholder and public engagement were prioritized to ensure representation from LVvNlmN Tlaqim V_J]qLV_T UVmpalVJA]]y q_LNllNilNmN_pNL Ja^^q_VpVNm A_L J]V^ApNvulnerable populations.
Data Ja]]NJpVa_A_LA_A]ymVm]NvNlATNLqiLApNLUA|AlLJ]V^ApNA_Lvq]_NlAIV]VpyLApASla^]aJA]mpApN A_LSNLNlA]maqlJNmilavVLV_T ASaq_LApVa_SalN_UA_JNL lVm\ A_Lvq]_NlAIV]VpyAmmNmm^N_pmA|AlLilaœ]NmwNlNqiLApNLpaV_J]qLNJ]V^ApNila[NJpVa_mand cascading impact scenarios. Mitigation strategies were revised and prioritized with a renewed focus on climate resilience and nature-based solutions. Strategies were also developed incorporating people with access and functional needs throughout each comia_N_paSpUN"-V_A]]y^NpUaLmSal^a_VpalV_TA_LNvA]qApVa_aS^VpVTApVa_NSSalpmwNlNLNœ_NLV_pUNi]A_^AV_pN_A_JNA_LV^i]N^N_pApVa_mplApNTy3AI]N-1 provides a timeline of the major plan update tasks and milestones over the planning process.
Table 2-1 AMHP Planning Timeline
Date 3Am\m People Involved February 2025
0NvVNwNLpUN"-A_LVLN_pVœNLcomponents that require update.
OEM AHMP Project Team
Collected and reviewed existing LaJq^N_pmV_J]qLV_TpUN3UlNApA_LA|AlLLN_pVœJApVa_A_L0Vm\Assessment (THIRA) along with resources for people with access and functional OEM AHMP Project Team
County of Los Angeles All-Hazards Mitigation Plan
Date 3Am\m People Involved
needs and people experiencing homelessness.
February 2025
Met with state Hazard Mitigation Planning Team.
OEM AHMP Project 3NA^A]%1Mitigation Division
LN_pVœNLpUNV_VpVA]]VmpaSmpA\NUa]LNlmand ensured organizations that work with and represent people with access and functional needs were engaged in the planning process. External stakeholders V_J]qLN_NVTUIalV_TJa^^q_VpVNm]aJA]A_LlNTVa_A]ATN_JVNmA_LapUNlm OEM AHMP Project Team
Conducted 2025 AHMP Kickoff Meetings with internal stakeholders.
OEM AHMP Project 3NA^_pNl_A]aq_py1pA\NUa]LNllaqiA]OES Mitigation Division NpNl^V_NLUA|AlLmpaINilaœ]NLV_J]qLV_TIapU_ApqlA]VNwV]L]A_LœlNNAlpUkqA\NNpJ A_LUq^A_-JAqmNLVNJyINlmNJqlVpypNllalVm^NpJ OEM AHMP Project 3NA^_pNl_A]aq_py1pA\NUa]LNllaqiExternal Stakeholder Group Drafted initial sections of the 2025 AHMP. OEM AHMP Project Team
Shared drafts of initial sections with internal and external stakeholders for their review.
OEM AHMP Project 3NA^_pNl_A]aq_py1pA\NUa]LNllaqiExternal Stakeholder laqiA]%1Mitigation Division Met with internal and external stakeholders to obtain feedback on draft plan elements.
OEM AHMP Project 3NA^_pNl_A]aq_py1pA\NUa]LNllaqiExternal Stakeholder laqiA]%1Mitigation Division County of Los Angeles
All-Hazards Mitigation Plan
Date 3Am\m People Involved March 2025
Developed the Public Outreach Engagement Plan to collect feedback from the public on the public draft of the 2025 AHMP.
OEM AHMP Project 3NA^A]%1Mitigation Division
Drafted subsequent sections of the 2025 AHMP including updating existing mitigation actions and developing new mitigation actions as needed.
OEM AHMP Project Team
Shared drafts of the subsequent sections with internal and external stakeholders for their review.
OEM AHMP Project 3NA^_pNl_A]aq_py1pA\NUa]LNllaqiExternal Stakeholder laqiA]%1Mitigation Division Met with internal and external stakeholders to obtain feedback on subsequent draft plan elements.
OEM AHMP Project 3NA^_pNl_A]aq_py1pA\NUa]LNllaqiExternal Stakeholder laqiA]%1Mitigation Division April/May 2025
lASpNLœ_A]mNJpVa_maSpUN
"-and produced a Final Draft AHMP.
OEM AHMP Project Team
Shared Final Draft of the AHMP with internal and external stakeholders for their review.
OEM AHMP Project 3NA^_pNl_A]aq_py1pA\NUa]LNllaqiExternal Stakeholder laqiA]%1Mitigation Division Met with internal and external stakeholders to obtain feedback on subsequent Final Draft AHMP.
OEM AHMP Project 3NA^_pNl_A]aq_py1pA\NUa]LNllaqiExternal Stakeholder laqiA]%1Mitigation Division Produced Final AHMP. OEM AHMP Project
Team
County of Los Angeles All-Hazards Mitigation Plan
2.2 Stakeholder Engagement Inclusive stakeholder involvement was essential to the planning process. The County N_mqlNL IlaAL lNilNmN_pApVa_ A_L iAlpVJViApVa_ Ja_mVmpN_p wVpU pUN ´:Ua]Na^^q_VpyiilaAJU´aqp]V_NLV_pUN%iNlApVa_A]lNA^NlTN_Jy%iNlApVa_mPlan (OAEOP). Key stakeholders that comprised the Hazard Mitigation Advisory Committee included:
• aq_pyLNiAlp^N_pmmqJUAmIqp_ap]V^VpNLpa-qI]VJ:al\m-qI]VJNA]pUA_L Regional Planning.
• Cities within the operational area (OA) and neighboring communities through Disaster Management Area Coordinators (DMACs) and city representation. • Non-TavNl_^N_pA] alTA_V|ApVa_m #%m V_J]qLV_T N_vVla_^N_pA] A_L disability advocacy groups.
• Special District partners managing critical infrastructure. • Representatives of academia and school districts. • Community representatives from Access and Functional Needs (AFN) populations and historically underrepresented populations. 0NTq]Al^NNpV_Tmwal\mUaimA_LSaJqmTlaqimwNlNUN]LpaTApUNlV_iqpA_LlNœ_Nmitigation strategies. Stakeholders were contacted and invited to participate in the 2025 AHMP planning process through email (please see email template in Appendix B-3). Stakeholder SNNLIAJ\wAmLaJq^N_pNLA_LV_JalialApNLV_papUNi]A_N_mqlV_Tdiverse perspectives informed the process. Tables 2-2 and 2-3 includes a list of representatives of each agency that contributed to the planning process.
Table 2-2 Hazard Mitigation Advisory Committee – _pNl_A]1pA\NUa]LNllaqi Department/
Agency
Name Title Planning Contribution
Los Angeles County %SœJNaSEmergency Management (OEM AHMP Project Team) Michael Morin
Emergency Management Coordinator
q_JpVa_NLAm]NALi]A__Nlm]NLi]A__V_T^NNpV_TmLlASpNLi]A_lNvVNwNLmitigation actions submitted by departments. Matthew Topoozian
Emergency Management Coordinator
County of Los Angeles
All-Hazards Mitigation Plan
Department/
Agency
Name Title Planning Contribution
Karen Haro Emergency
Management Coordinator
Girma Wollela
Emergency Management Coordinator
Los Angeles County Department of Aging and Disabilities Mike Tsao Administrative
Deputy
ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_LlASpmA_Lprovided feedback.
Henry Lopez
Program Manager
Carin Anderson
Administrative Services Manager
Keilah Kelso
Administrative Services Manager
Los Angeles County Chief Executive %SœJN– Anti0AJVm^VvNlmVpyand Inclusion Initiative Cesar Sanchez
Senior Analyst ppN_LNLi]A__V_T^NNpV_Tm
lNvVNwNLmNJpVa_LlASpmA_Lprovided feedback.
Los Angeles County Chief Executive %SœJN– Homeless Initiative Onnie Williams III
Principal Analyst ppN_LNLi]A__V_T^NNpV_Tm
lNvVNwNLmNJpVa_LlASpmA_Lprovided feedback.
Los Angeles County Chief Sustainability %SœJN
Matthew Gosner
Climate Resilience %SœJNl
ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_LlASpmA_Lprovided feedback.
County of Los Angeles All-Hazards Mitigation Plan
Department/
Agency
Name Title Planning Contribution
Los Angeles County Department of Beaches and Harbors
Katharine de la Cruz
Administrative Services Manager
Attended planning ^NNpV_TmlNvVNwNLmNJpVa_LlASpmA_Lprovided feedback.
Vanessa Huerta
1ASNpy%SœJNl
Los Angeles County Department of Economic Opportunity
Maritza Dubie
Human Services Administrator
ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_LlASpmA_Lprovided feedback.
Los Angeles County Department of Health Services
Elaine Forsyth
Senior Nursing Instructor
ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_LlASpmA_Lprovided feedback.
Isabel Sanchez
Disaster Services Specialist
Los Angeles County Department of Human Resources
Kevin Halbritter
Deputy Compliance %SœJNl
ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_LlASpmA_Lprovided feedback.
Los Angeles County Department of Parks and Recreation
Ramon Bernal
Disaster Services Analyst
ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_LlASpmA_Lprovided feedback.
Los Angeles County Department of Public Health
Elizabeth Rubin
Epidemiologist ppN_LNLi]A__V_T^NNpV_Tm
lNvVNwNLmNJpVa_LlASpmA_Lprovided feedback.
Los Angeles County Department of Public Social Services Manuel Gutierrez
Disaster Services Analyst
ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_LlASpmA_Lprovided feedback.
County of Los Angeles
All-Hazards Mitigation Plan
Department/
Agency
Name Title Planning Contribution
Los Angeles County Department of Public Works
Joseph Marble
Disaster Services Analyst
ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_LlASpmA_Lprovided feedback.
Loni Eazell Disaster
Services Specialist
Los Angeles County Department of Regional Planning
Thuy Hua Supervising
Planner
ppN_LNLi]A__V_T^NNpV_Tmreviewed section LlASpmA_Lprovided feedback.
Edgar De La Torre
Principal Regional Planner
Los Angeles County Fire Department
Nick Duvally
Deputy Fire Chief
ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_LlASpmA_Lprovided feedback.
Los Angeles County Internal Services Department
Juan-Raul Cardenas
GIS Analyst ppN_LNLi]A__V_T^NNpV_Tm
lNvVNwNLmNJpVa_LlASpmA_Lprovided feedback.
Los Angeles County Sheriff’s Department
Jordan Kennedy
Sergeant ppN_LNLi]A__V_T^NNpV_Tm
reviewed section LlASpmA_Lprovided feedback.
Table 2-3 Hazard Mitigation Advisory Committee – External 1pA\NUa]LNllaqi Department/Agency Planning Contribution
Access Services ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_ LlASpmA_LilavVLNLSNNLIAJ\Alzheimer’s Association California ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_ LlASpmA_LilavVLNLSNNLIAJ\A]VSal_VAavNl_al¯m%SœJNof Emergency Services ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_ LlASpmA_LilavVLNLSNNLIAJ\Catholic Charities ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_ LlASpmA_LilavVLNLSNNLIAJ\ County of Los Angeles All-Hazards Mitigation Plan
Department/Agency Planning Contribution
City of Beverly Hills Emergency Management Division
ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_ LlASpmA_LilavVLNLSNNLIAJ\ City of Long Beach Disaster Preparedness & Emergency Communications ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_ LlASpmA_LilavVLNLSNNLIAJ\ City of Los Angeles Emergency Management Department
ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_ LlASpmA_LilavVLNLSNNLIAJ\ Disability Community Resource Center
ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_ LlASpmA_LilavVLNLSNNLIAJ\ Disaster Management Area aalLV_ApallNA ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_ LlASpmA_LilavVLNLSNNLIAJ\Disaster Management Area aalLV_ApallNA ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_ LlASpmA_LilavVLNLSNNLIAJ\Disaster Management Area aalLV_ApallNA ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_ LlASpmA_LilavVLNLSNNLIAJ\Disaster Management Area aalLV_ApallNA ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_ LlASpmA_LilavVLNLSNNLIAJ\Disaster Management Area aalLV_ApallNA ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_ LlASpmA_LilavVLNLSNNLIAJ\Disaster Management Area aalLV_ApallNA ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_ LlASpmA_LilavVLNLSNNLIAJ\Disaster Management Area aalLV_ApallNA ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_ LlASpmA_LilavVLNLSNNLIAJ\Disaster Management Area aalLV_ApallNA Attended i]A__V_T^NNpV_TmlNvVNwNLmNJpVa_ LlASpmA_LilavVLNLSNNLIAJ\Eastern Los Angeles Regional Center ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_ LlASpmA_LilavVLNLSNNLIAJ\ Emergency Network Los Angeles
ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLsection LlASpmA_LilavVLNLSNNLIAJ\ Habitat for Humanity ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_ LlASpmA_LilavVLNLSNNLIAJ\ County of Los Angeles
All-Hazards Mitigation Plan
Department/Agency Planning Contribution
Harbor Regional Center ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_ LlASpmA_LilavVLNLSNNLIAJ\Lanterman Regional Center ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_ LlASpmA_LilavVLNLSNNLIAJ\!am_TN]Nmaq_py%SœJNaSEducation ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_ LlASpmA_LilavVLNLSNNLIAJ\ Los Angeles County Sanitation Districts
ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_ LlASpmA_LilavVLNLSNNLIAJ\ Los Angeles Metropolitan Transportation Authority
ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_ LlASpmA_LilavVLNLSNNLIAJ\ Los Angeles Regional Food Bank
ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_ LlASpmA_LilavVLNLSNNLIAJ\ Neighborhood Legal Services of Los Angeles County
ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_ LlASpmA_LilavVLNLSNNLIAJ\ Puente Hills Habitat Preservation Authority
ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_ LlASpmA_LilavVLNLSNNLIAJ\ South Central Los Angeles Regional Center
ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_ LlASpmA_LilavVLNLSNNLIAJ\ Westside Regional Center ppN_LNLi]A__V_T^NNpV_TmlNvVNwNLmNJpVa_ LlASpmA_Lprovided feedback.
2.3 Public Involvement and Outreach -qI]VJaqplNAJUNSSalpmAV^NLpaSampNlplA_miAlN_JyV_J]qmVvVpyA_LSalpVSyiqI]VJplqmpThe County engaged the public during the planning process through multiple media formats to share information and collect feedback taking into account language and other access and functional needs. A rolling outreach strategy was used to ensure that AmNAJUmNJpVa_wAmLlASpNLA_LlNvVNwNLIyi]A__V_TmpA\NUa]LNlmVpwAmJa_JqllN_p]y^ALNAvAV]AI]NSaliqI]VJJa^^N_pAly3aAJJa^i]VmUpUVmNAJUmNJpVa_wAmiampNL to the Los Angeles County Hazard Mitigation Program website as it was completed by the planning team. A survey designed to gauge community perceptions of hazard risks and mitigation priorities was used on the website (Appendix D). This approach ensured that the public was a key partner in every step of the planning process and had a voice as County of Los Angeles All-Hazards Mitigation Plan
each section was being developed by the planning team. A social media campaign using all LA County OEM social media channels was initiated to direct the public to the survey. 3a ALLlNmm NkqVpy pAlTNpNL aqplNAJU NSSalpm SaJqmNL a_ N_TATV_T UVmpalVJA]]yq_LNllNilNmN_pNL Ja^^q_VpVNm A_L # iaiq]ApVa_m qmV_T ^q]pV]V_TqA] A_LAJJNmmVI]N^ApNlVA]mA_LJq]pqlA]]yAiilailVApNpNJU_VkqNmmVLNSla^iqI]VJaqplNAJUstakeholders that wal\ wVpU al lNilNmN_p iNai]N wVpU AJJNmm A_L Sq_JpVa_A] _NNLmiNai]N NxiNlVN_JV_T Ua^N]Nmm_Nmm A_L A LVvNlmN AllAy aS Jq]pqlA] Tlaqim wNlNtargeted to participate in the Hazard Mitigation Advisory Committee. These measures ensured that the public had meaningful opportunities to participate in shaping the plan. 2.4 Review and Incorporation of Existing Plans and Reports The planning process included a comprehensive review of existing documents and protocols to ensure consistency and alignment. The 2020 All-Hazards Mitigation Plan mNlvNLAmpUNSaq_LApVa_A]LaJq^N_pSalpUVmqiLApNLLVpVa_A]]y\NyJa_JNipmSla^the 2023 Operational Area Emergency Operations Plan (OA%- mqJUAm^NlTN_Jy1qiialp q_JpVa_m 1m A_LLVmAmpNl^A_ATN^N_p AlNAmwNlNV_pNTlApNL3UN !amAngeles County Climate Vulnerability Assessment provided valuable insights into J]V^ApNlVm\mA_LmaJVA]mN_mVpVvVpywUV]N]aJA]]V^ApNJpVa_-]A_mN_mqlNLA]VT_^N_pwith mq_VJViA]J]V^ApNALAipApVa_V_VpVApVvNmqlpUNl^alNpUN41303UlNApA_LA|AlLLN_pVœJApVa_ A_L0Vm\mmNmm^N_p ilavVLNL JlVpVJA]LApASalVLN_pVSyV_TNva]vV_T pUlNApmA_LJAiAIV]Vpy pAlTNpmN_UA_JV_T pUNAJJqlAJyA_LlN]NvA_JNaS pUNplan. The demographic data from the 2020 U.S. Census was utilized to ensure an AJJqlApNlNilNmN_pApVa_aS!am_TN]Nmaq_pyµmiaiq]ApVa__awNmpV^ApNLApavNl^V]]Va_lNmVLN_pm3UNLN^aTlAiUVJIlNA\Law_V_J]qLNmÈVmiA_VJal!ApV_aÈ:UVpN È mVA_ È SlVJA_ ^NlVJA_ A_L È apUNl wVpU avNl È miNA\V_T A]A_TqATN apUNl pUA_ _T]VmU Ap Ua^N N^iUAmV|V_T pUN _NNL Sal ^q]pV]V_TqA] A_Lculturally appropriate outreach.
County of Los Angeles
All-Hazards Mitigation Plan
Table 2-4 xVmpV_T-]A_m"AimA_L0Nialpm
-]A_"Aial0Nialp Information to be Incorporated into the 2025 Updated AHMP Los Angeles County Operational Area Emergency Operations Plan (2023) Used to inform Section 6A|AlLLN_pVœJApVa_A_LRisk Assessment and Section 7: Mitigation Strategy Los Angeles County 2035 General Plan (2024)
Safety element mitigation policies used to inform Section 7 – Mitigation Strategy Los Angeles County Comprehensive Floodplain Management Plan (2021) Used to inform Section 6A|AlLLN_pVœJApVa_A_LRisk Assessment and Section 7: Mitigation Strategy SalN]N^N_pmlN]ApNLpaŔaaLUA|AlLm County of Los Angeles Floodplain Management Plan Progress Report from (2024) Used to inform Section 6A|AlLLN_pVœJApVa_A_LRisk Assessment and Section 7: Mitigation Strategy SalN]N^N_pmlN]ApNLpaŔaaLUA|AlLm County of Los Angeles Repetitive Loss Area Analysis Progress Report (2021) Used to inform Section 6A|AlLLN_pVœJApVa_A_LRisk Assessment and Section 7: Mitigation Strategy SalN]N^N_pmlN]ApNLpaŔaaLUA|AlLm Los Angeles County 2045 Climate Action Plan (2024)
Used to inform Section 6A|AlLLN_pVœJApVa_A_L0Vm\mmNmm^N_p1NJpVa_7"VpVTApVa_1plApNTyA_L Section 4: Climate Change for elements related to hazard risk posed by climate change Los Angeles County Fire Department Fire Plan (2023)
Used to inform Section 6A|AlLLN_pVœJApVa_A_LRisk Assessment and Section 7: Mitigation Strategy SalN]N^N_pmlN]ApNLpawV]L]A_LœlNUA|AlLm Our County: Los Angeles Countywide Sustainability Plan (2019) Used to inform Section 6A|AlLLN_pVœJApVa_A_L0Vm\mmNmm^N_p1NJpVa_7"VpVTApVa_1plApNTyA_L Section 4: Climate Change for elements related to hazard risk posed by climate change Los Angeles County Homeless Initiative Strategy Plan (2022) Used to inform vulnerable populations information across all sections of the plan.
Disability Among Adults in Los Angeles County (2019)
Used to inform vulnerable populations information across all sections of the plan.
Southern California Earthquake Data Center’s Earthquake Catalogs (Current as of 2025) Historical seismic information used in Section 6: A|AlLLN_pVœJApVa_A_L0Vm\mmNmm^N_p County of Los Angeles All-Hazards Mitigation Plan
-]A_"Aial0Nialp Information to be Incorporated into the 2025 Updated AHMP Maritime Tsunami Response Playbooks: Background Information and Guidance for Response and Hazard Mitigation Use (2016) Historical tsunami information used in Section 6: A|AlLLN_pVœJApVa_A_L0Vm\mmNmm^N_p FEMA Flood Insurance 1pqLy!am_TN]Nmaq_pyA]VSal_VA VmpalVJA]ŔaaLV_Sal^ApVa_qmNLV_1NJpVa_6: A|AlLLN_pVœJApVa_A_L0Vm\mmNmm^N_p U.S. Geological Survey (USGS): Rainfall and Landslides in Southern California (2015) Historical landslide information used in Section 6: A|AlLLN_pVœJApVa_A_L0Vm\mmNmm^N_p Burn Scar Information and Maps
VmpalVJA]œlNV_Sal^ApVa_qmNLV_1NJpVa_6: Hazard LN_pVœJApVa_A_L0Vm\mmNmm^N_p County of Los Angeles
All-Hazards Mitigation Plan
3 Community -laœ]N
County of Los AngelesAll-Hazards Mitigation Plan
3.1 Los Angeles County OverviewLos Angeles County is the most populous county in pUN 4_VpNL 1pApNmencompassing a diverse AllAy aS Ja^^q_VpVNm]A_LmJAiNm A_Linfrastructure. According to the most recent census LApA !am _TN]Nm aq_pyhas a population of approximately 10 million residents of which more than 1 million reside in unincorporated areas. The County’s LN^aTlAiUVJm TNaTlAiUVJ SNApqlNm A_L NJa_a^VJ AJpVvVpVNm ilNmN_p IapU q_VkqNaiialpq_VpVNmA_LmVT_VœJA_pJUA]]N_TNmSalUA|AlL^VpVTApVa_i]A__V_T3UVmqiLApNLcommunipy ilaœ]N V_pNTlApNm V_mVTUpm Sla^ pUN %iNlApVa_al Area Emergency Operations Plan (OA%- A_L lNŔNJpm JUA_TNm V_ iaiq]ApVa_ plN_Lm V_SlAmplqJpqlNLNvN]ai^N_pA_LJ]V^ApNlVm\mThe County Operational Area (OA) consists of all political subdivisions within the TNaTlAiUVJA] Iaq_LAlVNm aS !am _TN]Nm aq_py p N_Ja^iAmmNm œvN mqiNlvVmalVA]LVmplVJpmNVTUpVmAmpNl"A_ATN^N_plNAm"m V_JalialApNLJVpVNmmJUaa]districpmA_LAiilaxV^ApN]ymiNJVA]LVmplVJpm County of Los Angeles
All-Hazards Mitigation Plan
3.2 Geography and Land Use
1iA__V_TavNlmkqAlN^V]Nm !am _TN]Nm aq_pySNApqlNm LVvNlmN pNllAV_including coastal plainsvA]]Nym ^aq_pAV_m Vm]A_Lmand deserts. The County’s varied geography includes multiple microclimates that V_ŔqN_JN Vpm NxiamqlN pa_ApqlA] UA|AlLm mqJU Am NAlpUkqA\Nm pmq_A^VmwV]LœlNm ŔaaLm A_L]A_Lm]VLNm4lIA_ AlNAmiAlpVJq]Al]y pUNVpyaS!am_TN]NmA_LVpmmqllaq_LV_T^Nplaia]VpA_ lNTVa_AlNLN_mN]yiaiq]ApNLA_LUNAvV]yLNvN]aiNL_Ja_plAmplqlA]A_Lq_V_JalialApNLAlNAm often face unique vulnerabilities due to limited infrastructure and resources. Rural areas include the _TN]Nm A_L !am -ALlNm #ApVa_A] alNmpm wUVJU UAvN m^A]] Ja^^q_VpVNmJA^iTlaq_LmA_LLAyqmNAlNAm3UNlNAlNA]mapwaVm]A_LmwVpUV_pUNaq_py1A_pAApA]V_AA_L1A_]N^N_pN3UNaq_pyA]maV_J]qLNmAmVT_VœJA_pA^aq_paSWildland Urban Interface (WUI) areas where residential and commercial development meets underdeveloped wildland with vegetative fuels. Land use within the County is equally LVvNlmNwVpUA^VxaSlNmVLN_pVA]Ja^^NlJVA]V_LqmplVA]ATlVJq]pqlA]A_LaiN_spaces. Recent urban development in densely populated areas has increased impervious mqlSAJNm]V\NJa_JlNpNA_LAmiUA]pwUVJUlNpAV_UNApA_LJlNApNqlIA_UNApVm]A_Lm (UHI) that are much hotter than nearby rural areas3UVmiUN_a^N_a_N]NvApNmpN^iNlApqlNmespecially in low-V_Ja^NJa^^q_VpVNm]AJ\V_TTlNN_miAJNmSalJaa]V_TLLVpVa_A]]yurbanization affects stormwater management by reducing natural drainage and NxAJNlIApV_TŔaaLV_TlVm\mV_]aw-lying areas.3UNmN plN_Lm q_LNlmJalN pUN _NNL Sal mqmpAV_AI]N i]A__V_T mplApNTVNm mqJU Amila^apV_T TlNN_ V_SlAmplqJpqlN N_UA_JV_T mpal^wApNl mympN^m A_L^VpVTApV_T UNApVm]A_Lm pUlaqTU plNNi]A_pV_T A_L lNŔNJpVvN^ApNlVA]m3UNaq_py¯mLVvNlmN]A_LqmNmust be carefully managed to reduce vulnerabilities while supporting economic growth and environmental sustainability.
County of Los AngelesAll-Hazards Mitigation Plan
3.3 Social Vulnerability Social vulnerability is a crucial component to Los Angeles County’s hazard mitigation i]A__V_T 3UN aq_py Vm Ua^N pa A LVvNlmN iaiq]ApVa_ wVpU LVmiAlVpVNm V_ V_Ja^NUaqmV_T mpAIV]Vpy A_L AJJNmm pa lNmaqlJNm The Los Angeles County Anti-0AJVm^VvNlmVpy A_L _J]qmVa_ 0 _VpVApVvN JlNApNL A Ja^ilNUN_mVvN kqVpy xi]alNlwhich is a geospatial tool that explores multiple equity data points across Los Angeles County. The ARDI Equity Explorer includes varioum]AyNlm pUApvVmqA]V|N maJVA]NkqVpyeconomVJaiialpq_VpyUaqmV_TA_LUa^N]Nmm_NmmUNA]pU[qmpVJNIqV]pN_vVla_^N_pand disaster recovery data. The public can access this data at ceo.lacounty.gov/ardi/tools. Maps created using data from the ARDI Equity Explorer are in Appendix A-8.The US Centers for Disease Control and -lNvN_pVa_ LNœ_Nm maJVA]vulnerability as a community’s capacity to prepare for and respond to the stress of hazardous events ranging from natural disasters to human caused threats. The CDC’s Social Vulnerability Index (Figure 3.1) is designed to identify and quantify communities experiencing social vulnerability. The most recent CDC Social Vulnerability Index score from 2022 for Los Angeles County indicated a high level of vulnerability across four themes: maJVaNJa_a^VJ mpApqm UaqmNUa]LJUAlAJpNlVmpVJmlAJVA]A_LNpU_VJ^V_alVpympApqmA_LUaqmV_TpyiNplA_mialpApVa_Vulnerable populations VLN_pVœNLSal!am_TN]Nmaq_pypUApwV]]INJa_mVLNlNLV_pUNAHMP include:
Figure 3.1 CDC Social Vulnerability Index (CDC 2022)
County of Los Angeles
All-Hazards Mitigation Plan
x Low-_Ja^N 0NmVLN_pm:
Individuals living below or near the poverty line are often disproportionately affected by LVmAmpNlmLqNpa]V^VpNLœ_A_JVA]resources for emergency ilNiAlNL_Nmm lNmia_mN A_Lrecovery. x People with Access and
Functional Needs (AFN): Individuals with Access and Functional needs have increased challenges in ilNiAlNL_NmmNvAJqApVa_ mUN]pNlV_T AJJNmmV_Temergency services and recovery. Access and Functional Needs include but are not limited to people who have any combination in varying degree of: physicaldisabilities V_pN]]NJpqA] disabilitiesdevelopmental disabilities ^N_pA]health-lN]ApNL VmmqNm vVmqA]V^iAVl^N_pm UNAlV_Timpairments/deaf ^aIV]Vpyimpairments or chronic conditions. AFN also includea]LNl ALq]pm V_SA_pm A_L JUV]LlN_ people ]VvV_T V_ V_mpVpqpVa_A]V|NL mNppV_Tm people living below tUNiavNlpy]V_NalNxiNlVN_JV_TUa^N]Nmm_Nmmpeople with ]V^VpNL _T]VmU ilaœJVN_Jy al AlN _a_-_T]VmU miNA\Nlm al people who are transportation disadvantaged. x People Experiencing Homelessness (PEH): With an estimated over
individuals NxiNlVN_JV_T Ua^N]Nmm_Nmm pUVm iaiq]ApVa_ Vm iAlpVJq]Al]y Ap lVm\during extreme weather events and other disasters. x Immigration Status: Fear of engaging with government services based on immigration status can prevent residents from accessing critical resources.
Figure 3. 3 Breakdown of Language at Home in Los Angeles County (OAEOP 2023)
Figure 3.2 ŝƐĂďŝůŝƚLJ^ƚĂƟƐƟĐƐŝŶ>ŽƐŶŐĞůĞƐŽƵŶƚLJ (OAEOP 2023) County of Los AngelesAll-Hazards Mitigation Plan
x !V^VpNL_T]VmU-laœJVN_JyOver 40% of residents speak a language other pUA_ _T]VmU Ap Ua^N UVTU]VTUpV_T pUN _NNL Sal ^q]pV]V_TqA] A_L Jq]pqlA]]yappropriate outreach efforts. Language accessibility is critical to ensure all residents and visitors can obtain information and services during a disaster. See Figure 3.3 for a breakdown of languages spoken at home in Los Angeles County not including American Sign Language. 3UNœTqlNIN]awUVTU]VTUpmJNlpAV_vAlVAI]NmV_!am_TN]Nmaq_pypUAp^AyV_JlNAmNvq]_NlAIV]Vpy pa N^NlTN_JVNm A_L LVmAmpNlm 3a ALLlNmm pUNmN vq]_NlAIV]VpVNm pUNCounty’s mitigation planning includes equitable strategies designed to reduce risk and e_UA_JNlNmV]VN_JNA^a_TpUNmNiaiq]ApVa_m3AlTNpNLaqplNAJUV^ilavNLAJJNmmpalNmaqlJNm ilNiAlNL_Nmm NLqJApVa_ NvN_pm A_L Ja]]AIalApVa_ wVpU Ja^^q_Vpyorganizations are integral to these efforts.
Figure 3.4 Los Angeles County Vulnerability Variables (OAEOP 2023) County of Los Angeles
All-Hazards Mitigation Plan
The Federal Emergency Management Agency (FEMA) maintains the National Risk _LNxA^AiiV_Tpaa]pUApAmmNmmNmiammVI]NUA|AlLmA[qlVmLVJpVa_VmmqmJNipVI]Npain combination with the amount of loss that could result from those hazards. Los Angeles County ranks as the community with the most risk in the United States AJJalLV_T pa pUN " #ApVa_A] 0Vm\ _LNx JJalLV_T pa pUN #ApVa_A] 0Vm\ _LNxUA|AlLm wVpU pUN UVTUNmp lVm\ Sal !am _TN]Nm aq_py V_J]qLN NAlpUkqA\N wV]LœlNmNxplN^NUNApŔaaLV_TUVTUwV_LmA_L]A_Lm]VLNm3.4 Economy and Critical Infrastructure!am _TN]Nm aq_py Vm A T]aIA] NJa_a^VJ UqI UampV_T V_LqmplVNm mqJU AmN_pNlpAV_^N_p pNJU_a]aTy ^A_qSAJpqlV_T A_L V_pNl_ApVa_A] plALN 3UN -alp aS !amAngeles and the Port of Long Beach collectively form one of the world’s busiest trade TApNwAym q_LNlscoring the importance of protecting critical infrastructure from hazards including those exacerbated by climate change. Critical facilities provide mNlvVJNmA_LSq_JpVa_mNmmN_pVA]paAJa^^q_VpyNmiNJVA]]yLqlV_TA_LASpNlALVmAmpNlCommon types of crVpVJA]SAJV]VpVNmV_J]qLNIqp AlN _ap]V^VpNL pa œlN mpApVa_mia]VJNmpApVa_mUamiVpA]mmJUaa]mA_LqpV]VpVNmlVpVJA]SAJV]VpVNm^AyA]maV_J]qLNi]AJNmpUApJA_INqmNLSal mUN]pNlV_T Jaa]V_T JN_pNlmmpATV_TiqliamNmalapUNl]AlTNiqI]VJgathering spots such as community centers and libraries. Critical facilities include those operated by non-governmental and business partners vital for redevelopment or Figure 3.5 &
DEĂƟŽŶĂůZŝƐŬ/ŶĚĞdž (2025)
County of Los AngelesAll-Hazards Mitigation Plan
NJa_a^VJ mNJqlVpy :UN_ pUNmN AlN ASSNJpNL Iy A LVmAmpNl pUN aq_py ilavVLNmbusinesses and workers impacted by the disaster with vital information and resources. This allows them to maneuver effectively through disaster response toward recovery using its network of job centers and business hubs. Other critical infrastructure includes the facilities and industries that enable all facets of maJVNpypaSq_JpVa_V_J]qLV_TIqp_ap]V^VpNLpapUNSa]]awV_TJa^^q_Vpy]VSN]V_Nm x Safety and Security 3UN ^ylVAL aS ]aJA] ]Aw N_SalJN^N_p œlN A_L lNmJqN N^NlTN_Jy^A_ATN^N_pmJUaa]mA_LapUNlTavNl_^N_pmNlvVJNmpUAp^AV_pAV_ public safety and security.
x Communications: The interconnected network of infrastructure owners and aiNlApalmaSJa^^q_VJApVa_mmympN^mmqJUAmV_pNl_NppN]NiUa_NJN]]q]AlA_LapUNlJa^^q_VJApVa_mpawNlmJAI]NmApN]]VpNA_L^alN x 3lA_mialpApVa_ #Npwal\m: The County’s extensive network of laALwAym UVTUwAymlAV]wAymplA_mVpmympN^mand airports is essential for daily operations and disaster response. x Energy Systems: -awNlTN_NlApVa_SAJV]VpVNmN_NlTyLVmplVIqpVa__Npwal\mA_L pipelines are vulnerable to multiple types of hazards and threats. x Water and Wastewater Systems: Drought conditions and aging infrastructure at the over 220 different water agencies in Los Angeles County pose risks to water availability and quality. x Healthcare Facilities: Over 100 hospitals and numerous clinics serve the aq_py lNkqVlV_T laIqmp Ja_pV_TN_Jy i]A_m pa ^AV_pAV_ aiNlApVa_m LqlV_Tdisasters. x Food and Shelter: 3UN vAmp mympN^ aS SaaL ilaLqJpVa_ VN ATlVJq]pqlN LVmplVIqpVa_A_LlNpAV]A]a_TwVpUJa^^q_VpyUaqmV_TalmUN]pNlV_T
3.5 Climate and Environmental Conditions !am_TN]Nmaq_pySAJNmNmJA]ApV_TlVm\mSla^J]V^ApNJUA_TNmVT_VœJA_p]yV^iAJpV_TVpm N_vVla_^N_p NJa_a^y A_L Ja^^q_VpVNm 3UNmN JUA]]N_TNm V_J]qLN lVmV_TpN^iNlApqlNmila]a_TNLLlaqTUpm^alNSlNkqN_pA_LmNvNlNNxplN^NwNApUNlNvN_pmand their cascading effects. These risks highlight the critical need for adaptive planning pailapNJpvq]_NlAI]Niaiq]ApVa_mV_SlAmplqJpqlN A_L_ApqlA]lNmaqlJNm Ny J]V^ApN- County of Los Angeles
All-Hazards Mitigation Plan
related considerations referenced in the Los Angeles County Climate Action Plan that will be addressed in this AHMP includeIqpAlN_ap]V^VpNLpa: x Extreme Weather Events: Extreme temperatures in the Los Angeles region are NxiNJpNLpaV_JlNAmN
apULlyA_LwNpNxplN^NmAlNila[NJpNLpaV_pN_mVSy]NALV_Tto longer dry periods than historically experienced. These dry periods are expected pa IN Sa]]awNL Iy mVT_VœJA_p]y wNppNl Ja_LVpVa_m V_J]qLV_T Ap^amiUNlVJ lVvNlm IlV_TV_T^alNV_pN_mN lAV_SA]]3UVmiAppNl_^Ay lNmq]pV_V_JlNAmNLwApNlmJAlJVpy^qLm]VLNmA_LŔaaLV_T x Sea-!NvN] 0VmN: Coasta] Ja^^q_VpVNm AlN Ap UNVTUpN_NL lVm\ aS ŔaaLV_T A_L NlamVa_pUlNApN_V_TUa^NmIqmV_NmmNmA_LJlVpVJA]V_SlAmplqJpqlN Sea level rise can NxAJNlIApN pUNV^iAJpmaSUVTU pVLNmmpal^mqlTNm A_LUNAvyilNJViVpApVa_ A_LJA_]NALpaV_JlNAmNLJaAmpA]ŔaaLV_TA_LmUalN]V_NNlamVa_ x _JlNAmV_T :V]LœlN 0Vm\ ]V^ApN JUA_TN UAm V_pN_mVœNL wV]LœlN mNAma_m particularly in the County’s mountainouswV]L]A_LqlIA_V_pNlSAJN:4 and new and undeveloped regions. :V]LœlNm AlN ila[NJpNL pa V_JlNAmN V_ SlNkqN_Jy A_LV_pN_mVpyV_J]qLV_TV_ma^NAlNAm_apUVmpalVJA]]yV^iAJpNLIywV]LœlN _lNmia_mN pUNaq_pyUAmilValVpV|NLV_pNTlApV_TJ]V^ApNALAipApVa_mplApNTVNmV_paVpmUA|AlL^VpVTApVa_i]A__V_TAmaqp]V_NLV_pUN]V^ApN9q]_NlAIV]VpymmNmm^N_pA_Lthe OAEOP.
3.6 Regional Collaboration and Planning Efforts Los Angeles County’s size and complexity necessitates collaboration with numerous [qlVmLVJpVa_mATN_JVNmA_LJa^^q_VpyalTA_V|ApVa_m3UNaq_pyVmLNmVT_ApNLAmpUNOperational Area Coordinator and functions as an intermediate level in the State of California’s Standardized Emergency Management System (SEMS). In accordance with 1"1pUNaq_pymNlvNmAmpUNJa^^q_VJApVa_mA_LJaalLV_ApVa_]V_\INpwNN_]aJA]governments within Los Angeles County and the state government. Partnerships with AJALN^VJ V_mpVpqpVa_m _a_-ilaœpm A_L ilVvApN mNJpal mpA\NUa]LNlm support data Ja]]NJpVa_iqI]VJN_TATN^N_pA_LV__avApVvN^VpVTApVa_mplApNTVNmLLVpVa_A]]ypUNCounty has also adopted Emergency Support Functions (ESFs) as the primary emergency management coordination structure. ESFs group function-miNJVœJstakeho]LNlmwUawV]]JaalLV_ApN pUlaqTUaqpA]]iUAmNmaSN^NlTN_Jy^A_ATN^N_p County of Los Angeles All-Hazards Mitigation Plan
including function-miNJVœJ ^VpVTApVa_ AJpVvVpVNm al ^alN V_Sal^ApVa_ a_ lNTVa_A]N^NlTN_Jy^A_ATN^N_pJa]]AIalApVa_A_Li]A__V_TlNSNlN_JNpUNOAEOP. 3.7 Implications for Hazard Mitigation Planning Understanding the community is a critical aspect in hazard mitigation planning. This Ja^^q_Vpyilaœ]NwV]]V_Sal^\NyJa_mVLNlApVa_mV_mqImNkqN_pmNJpVa_maSpUN"-including but not limited to the following:
x Targeted Outreach: Include vulnerable populations and the business community in the planning process through equitable public outreach. x _SlAmplqJpqlN 0NmV]VN_JN -lValVpV|N pUN ilapNJpVa_ aS JlVpVJA] V_SlAmplqJpqlN V_J]qLV_T ialpm A_L plA_mialpApVa_ _Npwal\m N_NlTy mympN^m A_L wApNl A_L wAmpNwApNlmympN^mA^a_TapUNlm
x Climate Adaptation: Develop strategies to mitigate the impacts of climate JUA_TNSaJqmV_Ta_qlIA_UNApVm]A_LmmNA-]NvN]lVmNA_LwV]LœlNlVm\m x 0NTVa_A]aalLV_ApVa_ Strengthen direct collaboration within the OA between pUN aq_py ]aJA] [qlVmLVJpVa_m miNJVA] LVmplVJpm q_VœNL mJUaa] LVmplVJpm pUN business community and cross-sector non-governmental partners to enhance AwAlN_NmmilNiAlNL_NmmA_LlNmia_mNJAiAIV]Vties. x Transparent & Open Communication: _mqlNJa^^q_VJApVa_mAlNAJJNmmVI]N and clear to advance public trust and safety. Develop dashboards to demonstrate progress.
County of Los Angeles
All-Hazards Mitigation Plan
4 Climate Change
County of Los Angeles All-Hazards Mitigation Plan
4.1 Climate Change Overview Climate change refers to the changing effect of the Earth's J]V^ApNmympN^avNlpV^NV_J]qLV_T JUA_TNmV_ pN^iNlApqlNilNJViVpApVa_ A_LwV_LiAppNl_m ]V^ApN JUA_TNhad mVT_VœJA_p V^iAJpm a_ !am _TN]Nm aq_py ASSNJpV_T vAlVaqm AmiNJpm aS ]VSNN_vVla_^N_p V_SlAmplqJpqlN A_L mqmpAV_AI]N LNvN]ai^N_p A_L ilNmN_pm increasing lVm\mSla^A^i]VœNLUA|AlLmA_LJUA_TV_TIAmN]V_NmNTmNA]NvN] V_papUNSqpqlN. The lApNaS J]V^ApN JUA_TNUAm mVT_VœJA_p]y AJJN]NlApNLavNl pUNlast three decades and trends continues. This plan addresses the effects of climate change related to disasters wVpUV_pUNaq_pyA_LmplApNTVNmpa^VpVTApNlVm\mSaJqmV_Ta_ilNiAlNL_NmmlNmV]VN_JNand equity. ]V^ApN JUA_TN Ja_plVIqpNm pa^alNSlNkqN_p A_L V_pN_mN LVmAmpNlm mqJU Am ŔaaLmwV]LœlNm LlaqTUp A_L NxJNmmVvN UNAp 0VmV_T pN^iNlApqlNm A_L JUA_TV_T wNApUNlpatterns pose UNA]pUlVm\m]V\NUNAp-lN]ApNLV]]_NmmNmlNmiVlApalyVmmqNmA_LpUNmilNALof diseases. Hazard mitigation efforts aim to reduce the impacts and effects of greater hazards due to climate change. The economic impact of climate change has been mqImpA_pVA] ASSNJpV_T V_LqmplVNm mqJU Am ATlVJq]pqlN paqlVm^ A_L V_mqlA_JN with increasing risks due to accelerating climate changes. Greenhouse Gas (GHG) emissions are the main driver of J]V^ApNJUA_TNwUVJUJAqmNmV_JlNAmNL SlNkqN_Jy LqlApVa_ A_L mNvNlVpy aS NxplN^N wNApUNl A_L J]V^ApN-related LVmAmpNlm ]V^ApN JUA_TN NxAJNlIApNm AVl ia]]qpVa_ ]NALV_T pa iaal AVl kqA]Vpy A_Lhealth issues. GHG emissions from lNmVLN_pVA]IqV]LV_TmJa^^NlJVA]A_Linstitutional SAJV]VpVNm^A_qSAJpqlV_TV_LqmplVNmA_LJa_mplqJpVa_N_NlTyV_LqmplVNm oil and natural gas systems. plA_mialpApVa_ fossil N_NlTy wV]LœlNm A_L apUNl sources contribute to increased particulate matter and other pollutants in the air.
County of Los Angeles
All-Hazards Mitigation Plan
4.2 _pNTlApV_T]V^ApNUA_TNV_paA|AlL-laœ]NmIntegrating climate change into UA|AlLilaœ]NmV_va]vNmAmmNmmV_TpUNcurrent and future impacts of climate change on various hazards and incorporating this information into planning and mitigation strategies. This section highlights how climate change relates to these hazards and how the county is addressing climate change through hazard mitigation efforts which help protect the county’s residents and economies from the adverse effects of climate changes and climate-A^i]VœNLevents.4.2.1 Extreme HeatIncreasing temperatures and high heat events is one of the most conspicuous results of and a direct correlation between GHG pollution and climate change. Excessive pN^iNlApqlNmV_ pUN !am_TN]Nm lNTVa_ AlN NxiNJpNL paV_JlNAmN mVT_VœJA_p]y^alNvery hot days and warm nights. In addition to increasing baseline temperatures and NxplN^NUNApLqNpaJ]V^ApNJUA_TNUNApVm]A_LmNxAJNlIApNpN^iNlApqlNmA_LUVTUheat events. As development occurs and darker paved surfaces replace open land and vNTNpApVa_ pUNmN AlNAm INJa^N wAl^Nl Sal^V_T A_ ¬Vm]A_L aS UNAp !am _TN]NmCounty experiences more frequent and excessive heat due to climate change. This is currently a major risk and with unmitigated GHG emissions increasing heat will lead to even greater health issqNmV_JlNAmNLN_NlTyLN^A_LSalJaa]V_TA_LapUNlmplAV_ma_infrastructure.4.2.2 Flooding]aaLV_TV_ !am_TN]Nm aq_pyaJJqlmLqN pa NxplN^N lAV_SA]] NvN_pm JAqmV_T ŔAmUŔaaLm lVvNlV_N ŔaaLV_T A_L V_JlNAmNL mqlSAJN wApNl aAmpA] AlNAm V_ !am_TN]NmCounty are vulnerable to sea- ]NvN]lVmN 1!0 wUVJUNxAJNlIApNmJaAmpA]UA|AlLm]V\NŔaaLmmpal^mqlTNmA_LJUla_VJNlamVa_%pUNllN]ApNLUA|AlLmV_J]qLNŔaaLV_T_NAl Figure 4.1 Sources of GHG Emissions from within Los Angeles County (LA County ϮϬϮϰ͖ϮϬϰϱůŝŵĂƚĞĐƟŽŶWůĂŶͿ
County of Los AngelesAll-Hazards Mitigation Plan
pUN ^aqpUm aS mplNA^m A_L JUA__N]m ]A_Lm]VLNm A_L mNAwApNl wN]] V_plqmVa_ 1!0NxAJNlIApNmpUNV^iAJpmaSUVTUpVLNmmpal^mqlTNmA_LUNAvyilNJViVpApVa_ŔaaLV_Tand continued SLR will lead to more life safety concerns and increased damage to property and infrastructure.4.2.3 Drought-la]a_TNL LlaqTUpm UAvN INJa^N ^alN Ja^^a_ ASSNJpV_T pUN wApNl mqii]yATlVJq]pqlN A_L NJamympN^m aS !am _TN]Nm aq_py ly A_L wNp NxplN^Nm AlNprojected to increase and are likely to cause drier periods than what the region has historically experienced. 1aqpUNl_ A]VSal_VA ila[NJpNL pa TNp LlVNl wUV]N #alpUNl_ A]VSal_VA wV]] V_JlNAmN V_temperature. This will result in loss of snowpack within the Sierra Nevada Mountain lA_TN^NA_V_T]NmmwApNlSalA]]A]VSal_VA_mV_J]qLV_TSAl^NlmlNmVLN_pmA_LqpV]ities.
The State Water Resource Control Board proclaimed several water conservation N^NlTN_Jy lNTq]ApVa_m LqN pa mNvNlN LlaqTUp Ja_LVpVa_m pUAp lNkqVlNm Ja^^NlJVA]V_LqmplVA]A_LlNmVLN_pVA]Ja_mNlvApVa_NSSalpm-laJ]A^ApVa_mV_J]qLN x January 4, 2022: State Water Board adopted the prohibited wasteful water uses emergency regulation
x May 24, 2022: the State Water Board adopted the emergency regulation to ban decorative grass watering like non-functional turf irrigation x December 7, 2022: the State Water Board readopted the prohibited wAmpNSq]wApNlqmNmN^NlTN_JylNTq]ApVa_
x May 26, 2023: the State Water Board readopted the emergency regulation to ban decorative grass watering.
4.2.4 :V]LœlNwV]LœlNVmA_q_i]A__NLA_Lq_Ja_pla]]NLœlNV_A_AlNAaSJa^IqmpVI]NvNTNpApVa_3UNmNœlNmJA_NAmV]ymilNALINya_LpUN_ApqlA]AlNAmilV^AlV]yV_va]vV_TA_LUAvNAiapN_pVA]paJAqmNLA^ATNmaqpmVLNaSpUNiNlV^NpNl:V]LœlNilaIAIV]VpyLNiN_Lman ]aJA]wNApUNlJa_LVpVa_maqpLaalAJpVvVpVNmA_LA_yilNJNLV_TJa_LVpVa_mNT]apmaSlAV_]NALV_TpavNTNpApVa_TlawpUA_LpUN_LlyV_TJa_LVpVa_m A_LAiapN_pVA]VT_VpVa_NT]VTUp_V_TmplV\NAlma_LNIlVmIql_V_TN]NJplVJA]NkqVi^N_pSAV]qlN JAlpAV]iViNNpJ 3UN SlNkqN_Jy A_L V_pN_mVpy aS wV]LœlNm UAm V_JlNAmNL LlVvN_ Iy UVTUNl County of Los Angeles
All-Hazards Mitigation Plan
pN^iNlApqlNm ]awNl ilNJViVpApVa_ ]awNl lN]ApVvN Uq^VLVpy A_L ila]a_TNL LlaqTUpm3UNmN NvN_pm UAvN JAqmNL ]amm aS ]VSN LNmplay A_Lal LA^ATN pa ilaiNlpyV_SlAmplqJpqlNpUNN_vVla_^N_pA_LiamNTlNApNllVm\mLqNpaUVmpalVJA]LNvN]ai^N_ppatterns. The pV^N]V_N aS ^A[al wV]LœlN NvN_pm A_L AJlNATN Iql_NL V_ !am _TN]NmCounty is listed at Section 6.2 of the plan. 4.3 Climate Mitigation Strategies Los Angeles County is actively addressing climate change and implementing hazard mitigation strategies to reduce its impacts and build long-term resilience. The County SAJNmV_JlNAmV_TlVm\mSla^NxJNmmVvNUNApwV]LœlNmLlaqTUpmŔaaLmA_LmNA-level rVmNA]]aSwUVJUpUlNApN_Ja^^q_VpVNmV_SlAmplqJpqlNA_L_ApqlA]lNmaqlJNm3a ALLlNmm ^A_y aS pUNmN JUA]]N_TNm pUN aq_py UAm LNvN]aiNL Ja^ilNUN_mVvNJ]V^ApN i]A_m A_L mplApNTVNm pUAp V_pNTlApN J]V^ApN ALAipApVa_ mqmpAV_AI]N ]A_L qmNN^NlTN_Jy ilNiAlNL_Nmm A_L N_vVla_^N_pA] Ja_mNlvApVa_ y N_SalJV_T IqV]LV_TJaLNmV_vNmpV_T V_TlNN_V_SlAmplqJpqlNA_LmplN_TpUN_V_TJa^^q_VpyilNiAlNL_NmmLos Angeles County aims to minimize risks and enhance disaster resilience. These efforts align with state and federal climate policies and are designed to protect both current and future generations while encouraging a more sustainable and livable environment for all. 4.3.1 Climate Resilience Plans and Actions x Los Angeles County 2045 Climate Action Plan (2045 CAP): Establishes aggressive targets to reduce greenhouse gas emissions and achieve carbon neutrality by 2045. x :ApNla_mNlvApVa_ËlaqTUp0NmV]VN_JN"NAmqlNm Implements mandatory wApNl lNmplVJpVa_m ila^apNm lAV_wApNl UAlvNmpV_T A_L NxiA_Lm Tlaq_LwApNlrecharge and water recycling projects. x :V]LœlN"VpVTApVa_Ë9NTNpApVa_"A_ATN^N_p-laTlA^m Enforces Wildland 4lIA__pNlSAJN:4 JaLNmV_JlNAmNmSalNmp^A_ATN^N_ppNJU_VkqNmaligned with Traditional Ecological Knowledge (TEK) principles and practices of our native indigenous communities A_L mplN_TpUN_m œlN-resistant building and landscape requirements.
County of Los Angeles All-Hazards Mitigation Plan
x lNN_ _SlAmplqJpqlN Ë 4lIA_ aa]V_T _VpVApVvNm Expands tree planting aligned with TEK principles and practicesV_vNmpVTApNm lN^avV_TUAlL iAvNL mqlSAJNm A_L i]A_pV_T Tlaq_LJavNl qpV]V|Nm A_L ila^apNm iqI]VJ Jaa]V_TJN_pNlm A_L Ua^N UNAp ilNiAlNL_Nmm A_L N_JaqlATNm pUN qmN aS lNŔNJpVvN¬Jaa]laaœ_TA_LmqlSAJNmpa^VpVTApNpUNqlIA_UNApVm]A_L4 NSSNJt. x Heat Action Plan: Develops strategies to reduce the adverse health impacts of NxJNmmVvNUNAppUlaqTUiqI]VJmUALNmplqJpqlNmJaa]V_TJN_pNlmIqV]LV_TJaLNmand increased public awareness campaigns for all susceptible to extreme heat. 3UNmNmplApNTVJAJpVa_m lNŔNJp!am_TN]Nmaq_py¯m Ja^^Vp^N_p pa pAJ\]V_T J]V^ApNJUA_TN yV_pNTlApV_TilaAJpVvNia]VJVNmindigenous-V_Sal^NLilAJpVJNmcommunityLlVvN_ma]qpVa_mA_LlNmV]VN_pV_SlAmplqJpqlN!am_TN]Nmaq_pyVm_apa_]y^VpVTApV_T current risks but also preparing for a future where communities can thrive in an everchanging dynamic environment.
4.4 Climate Change Conclusion 3UlaqTUilaAJpVvNia]VJVNmA_LJa^^q_VpyN_TATN^N_p!am_TN]Nmaq_pymplVvNmpa _AvVTApN pUN Ja^i]NxVpVNm aS A JUA_TV_T J]V^ApN A_L mASNTqAlL Vpm iNai]NN_vVla_^N_pV_SlAmplqJpqlNA_LNJa_a^VNm3UVmAiilaAJUUN]im^V_V^V|NpUNlVm\mA_Limpacts associated with climate-related hazards. Addressing climate change in hazard ^VpVTApVa_UN]iN_UA_JNmASNlUNA]pUVNlA_L^alNmqmpAV_AI]NJa^^q_VpVNm County of Los Angeles
All-Hazards Mitigation Plan
5 Integrating Access and
Functional Needs (AFN)
into Hazard Mitigation
County of Los Angeles All-Hazards Mitigation Plan
5.1 AFN Introduction Modern hazard mitigation planning increasingly recognizes that resilient communities must address the needs of all residents —including those with access and functional _NNLm# VmpalVJA]]yV_LVvVLqA]mwVpULVmAIV]VpVNm VNV_J]qLV_TIqp_ap]V^VpNLpayaqpU pUamN NJa_a^VJA]]y LNilNmmNL ilNT_A_p NpJ JUla_VJ UNA]pU Ja_LVpVa_m]A_TqATN IAllVNlm al plA_mialpApVa_ LVmALvA_pATNm UAvNbeen underrepresented in emergency planning. As evidenced by the best practices for stakeholder inclusion and furpUNl mqiialpNL Iy _ApVa_A] ilNiAlNL_Nmm SlA^Nwal\m V_pNTlApV_T # considerations leads to plans that are more inclusive and effective. By proactively N_TATV_T#iaiq]ApVa_mA_LmqiialpATN_JVNmV_NvNlyiUAmNSla^preparedness pUlaqTUlNJavNlyAUA|AlL^VpVTApVa_i]A_JA_lNLqJN]ammNmV^ilavNNvAJqApVa_A_L mUN]pNlV_TaqpJa^NmA_LIqV]LplqmpINpwNN_N^NlTN_Jy^A_ATN^N_pATN_JVNmA_Lthe communities they serve.
5.2 Inclusion of AFN and Vulnerable Populations in Planning ^A[alJa^ia_N_paSNSSNJpVvN^VpVTApVa_i]A__V_TVmA¬wUa]NJa^^q_VpyAiilaAJUIncorporating AFN voices into the planning process is crucial because these stakeholders offer real-world insights into the challenges they face during emergencies. Key stNimpapUVmilaJNmmV_J]qLNIqpAlN_ap]V^VpNLpa x 1pA\NUa]LNl _TATN^N_p Ensure that representatives from disability ALvaJAJyTlaqimJa^^q_Vpy-IAmNLalTA_V|ApVa_mA_LmNlvVJNilavVLNlmmqJUas local health departments and transportation agencies) are engaged early in pUNi]A__V_TilaJNmm3UNVlœlmpUA_LNxiNlVN_JNmUN]iVLentify practical barriers that might otherwise be overlooked. x Public Participation: _JalialApV_T iqI]VJ mpA\NUa]LNlm pUlaqTU ^NNpV_Tm mqlvNymA_LapUNlaqplNAJUpaJAipqlNpUNLVvNlmN_NNLmaS#iaiq]ApVa_mThis input is vital to overcoming historical marginalization and ensuring that mitigation actions are relevant and equitable to the entire population. x Ongoing Interagency Collaboration: Develop a hazard mitigation planning advisory committee and interagency working groups that include AFN stakeholders. These groups can guide both the planning process and the review aSNxVmpV_Ti]A_mN_mqlV_TpUAp#VmmqNmAlNSq]]yV_pNTlApNLSla^pUN outset.
County of Los Angeles
All-Hazards Mitigation Plan
5.2.1 Integrating AFN into the Overall AHMPIntegrating AFN considerations is not a stand-A]a_N pAm\ Vp ^qmp IN V_pNl]AJNLthroughout the entire hazard mitigation planning process. This includes:
x 0Vm\mmNmm^N_pm Incorporate AFN data into all risk assessments to ensure that pUNmiNJVœJvq]_NlAIV]VpVNmaSpUNmNiaiq]ApVa_mAlNlNŔNJpNLV_UA|AlL^AimA_Lvulnerability index data. x Mitigation Strategy Development: Ensure that every mitigation action is NxA^V_NLSalVpmV^iAJpa_#iaiq]ApVa_malNxA^i]NwUN_i]A__V_TSal ŔaaLJa_pla]alwV]LœlNilNvN_pVa_ila[NJpmlNvVNwUawpUNmNila[NJpmJA_INimproved to meet the needs of people with access and functional needs. x -]A_ 0NvVNw A_L 4iLApN Ensure planning processes include regular AFN review and updates. Includes but not limited to:
o Surveys of community needso Consultations with AFN advisory groupso Integration of new technological or infrastructural solutions x q_LV_T A_L 0NmaqlJN ]]aJApVa_ Clearly identify funding streams and resource commitments for AFN-miNJVœJ ila[NJpm 3UVm Jaq]L V_va]vN pAlTNpNL TlA_pmSla^SNLNlA]ilaTlA^mNTA|AlL"VpVTApVa_mmVmpA_JN mpApNSq_LV_T LNLVJApNLpaAJJNmmVI]NV_SlAmplqJpqlNV^ilavN^N_pmA_L]aJAl resources such as the Productivity Investment Fund that can be accessed to improve the NSSNJpVvN_NmmA_LNSœJVN_JyaSaq_pyaiNlApVa_m
5.3 Assessment of AFN NeedsUnderstanding the specific needs of AFN populations requires both quantitative and qualitative approaches:
x ApAa]]NJpVa_A_L0Vm\mmNmm^N_p Use existing resourcesJa^^q_Vpy mqlvNym outreach and risk assessments to help identify the number and types of individuals with AFN at the local community level. Evaluate the regional TNaTlAiUVJLVmplVIqpVa_vq]_NlAIV]VpVNmA_LmiNJVSVJlNkqVlN^N_pmbefore and after emergencies.
County of Los AngelesAll-Hazards Mitigation Plan
x lA^Nwal\mSal_A]ymVm Adopt structured methodologies such as C-MIST a^^q_VJApVa_"AV_pAV_V_TNA]pU_LNiN_LN_JN1qiialp1ASNpyA_LTransportation) to assess/ document AFN requirements. x C-MIST Explanation
o Communication_LVvVLqA]mwVpUUNAlV_TvVmVa_JaT_VpVvNalmiNNJU limitations may require alternative communication methods to receive or express information during emergencies. o Medical / Health Needs: People with complex medical conditions rely a_^NLVJApVa_m^NLVJA]NkqVi^N_palmiNJVA]V|NLJAlNpa^AV_pAV_their health and prevent complications. o Independence3UamNwUaqmN^aIV]VpyLNvVJNmAmmVmpVvNpNJU_a]aTy or service animals need uninterrupted access to maintain their independence and daily functions. o Supervision & Safety: Some individuals require continuous support for mASNpyJa^SalpalN^apVa_A]wN]]-INV_TV_J]qLV_TpUamNwVpU^N^alyVmmqNmimyJUVAplVJJa_LVpVa_malV_pN]]NJpqA]LVmAIV]VpVNm o Transportation: Individuals without personal transportation or with ^aIV]Vpy]V^VpApVa_m_NNLAJJNmmVI]NA_LlN]VAI]NaipVa_mNmiNJVA]]yV_emergencies and evacuations. x _pNTlApV_T9q]_NlAIV]VpymmNmm^N_pm Leverage tools from local climate vulnerability assessments and hazard mitigation plan reviews to identify areas where AFN populations overlap with high-lVm\|a_NmNTS]aaLi]AV_m County of Los Angeles
All-Hazards Mitigation Plan
wildfire-prone areas). This integration helps prioritize mitigation actions in regions where vulnerable populations are most exposed.
5.4 Coordination with AFN Support Agencies Effective mitigation planning requires robust coordination with both governmental and nongovernmental agencies that serve AFN populations. Best practices include:
x Formal Partnerships: Establish relationships and partnerships with agencies mqJU Am iqI]VJ UNA]pU LNiAlp^N_pm maJVA] mNlvVJNm plA_mialpApVa_ AqpUalVpVNm community-IAmNL alTA_V|ApVa_m A_L LVmAIV]Vpy ALvaJAJy alTA_V|ApVa_m3UNmN iAlp_NlmUVimN_mqlN pUAp pUNlNVmJ]NAla_Toing communication and that roles A_LlNmia_mVIV]VpVNmAlNLN]V_NApNLINSalNLqlV_TA_LASpNlLVmAmpNlm x Joint Training and Exercises: a_LqJp lNTq]Al [aV_p^NNpV_Tm A_L NxNlJVmNm that include AFN components and identify additional resources to support the needs of the AFN community. These actions will help prepare all stakeholders to work together during a crisis and help identify gaps in current plans. x Outreach and Information Dissemination: _mqlN pUAp A]] V_Sal^ApVa_ IapU pre-V_JVLN_p ilNiAlNL_Nmm ^NmmATNm lNmia_mN ^NAmqlNm A_L iamp-incident recovery plans are accessible to all audiences. This includes using multiple ]A_TqATNm vAlVaqm Ja^^q_VJApVa_ Sal^Apm NT ]AlTN-ilV_p AqLVa mVT_-]A_TqATNA_LLVTVpA]Sal^Apm A_LJq]pqlA]]yAiilailVApN^NmmATV_TpalNAJUA]]segments of the community.
5.5 AFN Conclusion UA|AlL^VpVTApVa_i]A_IqV]LmASaq_LApVa_SalA lNmV]VN_pV_J]qmVvN Ja^^q_Vpy yensuring that AFN and other vulnerable populations are included in every phase of i]A__V_T Sla^ V_VpVA] mpA\NUa]LNl N_TATN^N_p pa pUN LNvN]ai^N_p aS pAV]alNLmitigation AJpVa_m A_L JaalLV_ApNL lNmia_mN mplApNTVNm Ja^^q_VpVNm JA_ ^V_V^V|Ndisaster impacts and foster long-term resilience. Drawing on best practices from _ApVa_A]SlA^Nwal\mA_L]aJA]i]A__V_TTqVLNmA_LIyV^i]N^N_pV_T-compliant shelter operations emergency managers can create a plan that truly serves every member of the community. This inclusive approach not only saves lives and property during disasters but also strengthens community trust and the overall effectiveness of emergency management efforts.
County of Los Angeles All-Hazards Mitigation Plan
6 A|AlLLN_pVœJApVa_A_L
Risk Assessment
County of Los Angeles
All-Hazards Mitigation Plan
6.1 A|AlLLN_pVœJApVa_%vNlvVNw3UN UA|AlL VLN_pVœJApVa_ A_L lVm\ AmmNmm^N_p ilaJNmmprovide a foundation for Los _TN]Nm aq_py¯m UA|AlL ^VpVTApVa_ i]A__V_T NSSalpm Iy VLN_pVSyV_T ilaœ]V_T A_LAmmNmmV_TpUNlVm\mAmmaJVApNLwVpU_ApqlA]pNJU_a]aTVJA]A_LUq^A_-caused hazards. This section builds on the framework established in the 2020 HazalL"VpVTApVa_-]A_incorporating insights from the 2023 Operational Area Emergency Operations Plan (OA%- pUN4 Los Angeles 3UlNApA_LA|AlLLN_pVœJApVa_A_L0Vm\mmNmm^N_p(THIRA) pUN Los Angeles County Climate Vulnerability Assessment the State of A]VSal_VA A|AlL"VpVTApVa_ -]A_ 1"- and the Federal Emergency Management Agency (FEMA) National Risk Index. Based on these sources hazards were included and addressed in the 2025 AHMP AJJalLV_T pa pUNVlSlNkqN_JymNvNlVpyA_LV^iAJp pa!am_TN]Nmaq_pymNNIN]awTable 6-1. Hazards that did not meet the threshold of moderate risk will not be prioritized within the plan. LLVpVa_A]]y pUlNN _Nw _ApqlA] UA|AlLm xplN^N NAplaqTUpA_L1NvNlN:V_L3al_ALa and four human-caused hazards "Amm9Va]N_JNyINl_JVLN_pm3lA_mialpApVa__JVLN_pmA_L-qI]VJNA]pU^NlTN_JVNm are included in the 2025 AHMP.
Table 6-1 Hazard Inclusion/ Omission
Hazard Comment
Earthquake Hazard is included in the plan due to its high SlNkqN_Jy mNvNlVpyA_LV^iAJppa!am_TN]Nmaq_py
:V]LœlN Hazard is included in the plan due to its high SlNkqN_Jy mNvNlVpyA_LV^iAJppa!am_TN]Nmaq_py
Heat Wave Hazard is included in the plan due to its high SlNkqN_Jy mNvNlVpyA_LV^iAJppa!am_TN]Nmaq_py
Tornado Hazard is included in the plan due to its high SlNkqN_Jy mNvNlVpy A_L V^iAJp pa !am _TN]Nm aq_py Tornado is incorporated with the Severe Wind/ Tornado hazard ilaœ]N.
Land Movement Hazard is included in the plan due to its high SlNkqN_Jy mNvNlVpyA_LV^iAJppa!am_TN]Nmaq_py
County of Los Angeles All-Hazards Mitigation Plan
Hazard Comment
Lightning Hazard is included in the plan due to its high SlNkqN_Jy mNvNlVpy A_L V^iAJp pa !am _TN]Nm aq_py Lightening is incorporated wVpUpUN:V]LœlNand Flooding hazard ilaœ]Nm.
Flooding HazAlLVmV_J]qLNLV_pUNi]A_LqNpaVpmSlNkqN_JymNvNlVpyA_L impact to Los Angeles County. 3UN ]aaLV_T UA|AlL ilaœ]Nincorporates both Riverine and Coastal Flooding.
Drought HazAlLVmV_J]qLNLV_pUNi]A_LqNpaVpmSlNkqN_JymNvNlVpyA_L impact to Los Angeles County.
Strong Wind Hazard is included in the i]A_LqNpaVpmSlNkqN_JymNvNlVpyA_L impact to Los Angeles County. Strong Wind is incorporated with the Severe Wind and 3al_ALaUA|AlLilaœ]N Tsunami HazAlLVmV_J]qLNLV_pUNi]A_LqNpaVpmSlNkqN_JymNvNlVpyA_L impact to Los Angeles County.
Winter Weather Hazard is omitted from the plan due to its minimal SlNkqN_Jy mNvNlVpyA_LV^iAJppa!am_TN]Nmaq_py
Hail Hazard is omitted from the plan due to its minimal SlNkqN_Jy mNvNlVpyA_LV^iAJppa!am_TN]Nmaq_py
Avalanche Hazard is omitted from the plan due to its minimal SlNkqN_Jy mNvNlVpyA_LV^iAJppa!am_TN]Nmaq_py
Cold Wave Hazard is omitted from the plan due to its lack of SlNkqN_Jy mNvNlVpyA_LV^iAJppa!am_TN]Nmaq_py
Hurricane Hazard is omitted from the plan due to its lack of SlNkqN_Jy mNvNlVpyA_LV^iAJppa!am_TN]Nmaq_py
Ice Storm Hazard is omitted from the plan due to its lack of SlNkqN_Jy mNvNlVpyA_LV^iAJppa!am_TN]Nmaq_py
Volcanic Activity Hazard is omitted from the plan due to its lack of SlNkqN_Jy mNvNlVpyA_LV^iAJppa!am_TN]Nmaq_py
County of Los Angeles
All-Hazards Mitigation Plan
!am _TN]Nm aq_py SAJNm A wVLN lA_TN aS UA|AlLm LqN pa Vpm TNaTlAiUVJ LVvNlmVpyiaiq]ApVa_LN_mVpyA_LNJa_a^VJmVT_VœJA_JN3UNSa]]awV_TUA|AlLmwNlNVLN_pVœNLA_LilValVpV|NLSla^pUNilNvVaqm]y^N_pVa_NLmaqlJNmIAmNLa_UVmpalVJA]aJJqllN_JNmpopN_pVA]V^iAJpmA_LSqpqlNlVm\m
1. :V]LœlN2. Earthquake 3. Extreme Heat 4. Drought 5. Flooding 6. Dam Failure 7. Land Movement 8. Tsunami 9. Severe Wind and Tornado 10. Mass Violence 11. Cybersecurity Incidents 12. Transportation Incidents 13. Public Health Emergencies ^a_T pUNmN UA|AlLm six wNlN VLN_pVœNL pa IN iapN_pVA]]y NxAJNlIApNL Iy J]V^ApN change V_J]qLV_TwV]LœlNNxplN^NUNApLlaqTUpŔaaLV_T]A_L^avN^N_pA_LmNvNlN wind and tornadoes. Additional human-caused hazards were included based on the 30V_J]qLV_T^AmmvVa]N_JNJyINlmNJqlVpyV_JVLN_pmplA_mialpApVa_V_JVLN_pmand public health emergencies. The results of the public Personal Disaster Impact 1qlvNyvA]VLApNLpUAppUNmNUA|AlLmAlNaSmVT_VœJA_pJa_JNl_paJaq_pylNmVLN_pmA risk assessment table comparing hazards to critical infrastructure is in Appendix C.
Table 6-2 UA_TNmV_NvN]ai^N_pA_L9q]_NlAIV]Vpy
Hazard Change (Increase/ Decrease) 0NAma_
Earthquake No Change While new construction adheres to
modern seismic codes aging infrastructure in high seismic zones remain vulnerable. Continued population growth in older neighborhoods with limited County of Los Angeles All-Hazards Mitigation Plan
Hazard Change (Increase/ Decrease) 0NAma_
lNplaœppV_TV_JlNAmNmavNlA]]exposure.
:V]LœlN
(Lightning)
Increase in Vulnerability Urban expansion into WildlandUrban Interface (WUI) areas has increased the number of homes at risk. Post 2020 development in UVTUœlNmNvNlVpy|a_NmUAmJa_pV_qNLpUaqTULNSN_mVI]NmiAJNlNTq]ApVa_mA_L_NwœlNsafe planning are improving resilience for new builds.
Extreme Heat Increase in Vulnerability -aiq]ApVa_LN_mVpyurban heat islands and development in inland valleys increases exposure. Older multi-family units without air conditioning remain a concern. More outdoor workers and people experiencing homelessness (PEH) add to vulnerable population.
Land
Movement
Stable to Slight Increase Most new development avoids
known landslide-prone areas due to zoning and geotechnical review. awNvNl climate-driven precipitation variability and wV]LœlNmJa_pV_qNpaLNmpAIV]V|Nslopes in developed areas.
Flooding
(Lightning)
Increase in Vulnerability New impervious surfaces from
development increase stormwater lq_aSS%]LNlŔaaLJa_pla]infrastructure is strained under UNAvVNl^alNSlNkqN_plAV_NvN_pm.
County of Los Angeles
All-Hazards Mitigation Plan
Hazard Change (Increase/ Decrease) 0NAma_
Drought Increase in Vulnerability Continued population growth and water demand in arid and semiarid zones has outpaced gains in conservation. Agricultural vulnerability persists in high desert areas.
Severe Wind and Tornado
Increase in Vulnerability Los Angeles County is
experiencing more frequent and V_pN_mNwV_LNvN_pmV_J]qLV_Ttornadoes. As urban development NxiA_LmplNNJA_aiVNmA_Loverhead utilities in densely developed areas continue to contribute to cascading hazards. In lNmia_mNNSSalpmAlNq_LNlwAypaunderground utility lines in highrisk areas.
Tsunami Stable Revised tsunami inundation maps
UAvNlNœ_NLpUNAp-risk zones. New developments in coastal areas are largely outside the updated hazard areas or comply with stricter coastal building codes.
Dam Failure Stable/ Slight Increase While no new major dams have INN_Ja_mplqJpNLV_lNJN_pyNAlmdownstream development continues to increase population and critical infrastructure exposure within inundation zones.
County of Los AngelesAll-Hazards Mitigation Plan
County of Los AngelesAll-Hazards Mitigation Plan6.2 :V]LœlN6.2.1 Nature:V]LœlNm AlN SAmp-^avV_T q_Ja_pla]]NLœlNmpUApJa_mq^NvNTNpApVa_A_LlAiVL]ymilNALaSpN_pUlNApN_V_T]VvNmmplqJpqlNmA_L V_SlAmplqJpqlN 3UNmN œlNm JA_ INVT_VpNL Iy _ApqlA] JAqmNm mqJU Am]VTUp_V_T al Uq^A_ AJpVvVpVNm V_J]qLV_Tunattended ca^iœlNm Law_NL iawNl]V_NmA_LAlma_3UNV_JlNAmV_TSlNkqN_JyLqlApVa_ A_LV_pN_mVpyaSwV]LœlNmV_ !amAngeles County are possibly linked to the JUA_TV_T J]V^ApN wVpU UappNlpN^iNlApqlNm ila]a_TNL LlaqTUpm A_Lreduced humidity levels making the rNTVa_UVTU]ymqmJNipVI]NpaœlNmAJpalm_ŔqN_JV_T:V]LœlN NUAvVal
x Topography: Fires spread
more rapidly on steep slopes and are often driven by the Santa Ana winds. x Fuel LoadN_mNLly
vegetation and high tree mortality increase fire intensity. x Weather ConditionsVTUpN^iNlApqlNmmpla_TwV_LmA_L]awUq^VLVpy N]NvApNSVlNlVm\wVpUpUNJUA_TV_TJ]V^ApNJa_plVIqpV_TpaA]N_TpUN_NLSVlNseason.
County of Los Angeles
All-Hazards Mitigation Plan
:V]LœlNmA]maJlNApNmNJa_LAlyUA|AlLmmqJUAmiaalAVlkqA]Vpy]A_Lm]VLNmŔaaLV_TA_L LNIlVm Ŕawm—especially in areas with recent burn scars where vegetation loss increases soil instability. 6.2.2 Location !am _TN]Nm aq_py Vm a_N aS pUN ^amp wV]LœlN-prone regions in the United States. Based on the Department of Forestry and Fire Protection (CAL FIRE) Fire Hazard 1NvNlVpy ?a_N 1? ^Aim mVT_VœJA_p wV]LœlN lVm\ NxVmpm V_ pUN 1A_pA "a_VJA"aq_pAV_m1A_AIlVN]"aq_pAV_m-A]am9NlLNmV]]mA_LPuente Hills. The 2024 THIRA and Los Angeles County Climate Vulnerability Assessment identify an increasing risk to communities located in or near these high-risk areas. !am_TN]Nmaq_pyUAmpUlNNilV^AlywV]LœlN^A_ATN^N_p|a_Nm x NLNlA]0Nmia_mVIV]VpylNAm0m Lands administered or controlled by the federal government where federal agencies have administrative and protection responsibility for wildfires. x 1pApN0Nmia_mVIV]VpylNAm10m Wildland areas where CAL FIRE is responsible for suppression efforts.
x !aJA]0Nmia_mVIV]VpylNAm!0m Developed regions where local ATN_JVNmmqJUAm!am_TN]Nmaq_pyVlNNiAlp^N_p!a ilavVLN fire protection.
alAINppNlvVmqA]lNilNmN_pApVa_aSpUVm:V]LœlNA|AlLwVpUV_pUN!aq_pyi]A__V_TAlNA i]NAmN lNSNlN_JNiiN_LVx _J]qLNL V_iiN_LVx AlN mNvNlA] VlN A|AlLSeverity Zone maps for reference. 6.2.3 Extent JJalLV_Tpa!0¯mVlNA|AlL1NvNlVpy?a_N1? ^Aim!am_TN]Nmaq_pycontains:
x 386.06 square miles (8.11%) classified as Very High Fire Hazard Severity ?a_N1? V_!aJA]0Nmia_mVIV]VpylNAm!0m
x 625.01 square miles (13.13%) classified as Very High (FHSZ) in State 0Nmia_mVIV]VpylNAm10m.
:V]LœlNmiamNAmVT_VœJA_ppUlNAp_apa_]ypUlaqTUpUNV^^NLVApNLA^ATNpUNyJAqmNpa]VvNmilaiNlpyA_L_ApqlA]lNmaqlJNmIqpA]mapUlaqTUpUNmNJa_LAlyUA|AlLmpUApJa_pV_qNASpNlpUNŔA^NmAlNNxpV_TqVmUNL_pUNASpNl^ApUaSAœlNJa^^q_VpVNmaSpN_SAJNV_JlNAmNLlVm\maSŔAmUŔaaLmLNIlVmŔawm A_L LNTlALNL AVl kqA]Vpy 3UNmN iamp-œlN V^iAJpm JA_ Ja^iaq_L pUN V_VpVA]LNmplqJpVa_i]AJV_T ALLVpVa_A] mplAV_a_V_SlAmplqJpqlN UNA]pU mympN^m A_L lNJavery efforts.
County of Los Angeles All-Hazards Mitigation Plan
6.2.4 History !am _TN]Nm aq_py UAm NxiNlVN_JNL _q^Nlaqm LNvAmpApV_T wV]LœlNm V_ lNJN_pLNJALNmV_J]qLV_T x Canyon Fire (1968) –
ql_NLAJlNmLNmplayNLUa^NmA_L]NL
to mass evacuations.
x Old Topanga Fire (1993) – a_mq^NL
AJlNmLNmplayV_T
structures and causing three fatalities.
x Sayre Fire (2008) – NmplayNLmplqJpqlNmV_J]qLV_TavNl^aIV]N homes.
x Station Fire (2009) – 3UN]AlTNmpSVlNV_!am_TN]Nmaq_pyUVmpaly Iql_V_T
AJlNmLNmplayV_TmplqJpqlNmA_LJAqmV_Tpwafirefighter fatalities. x Woolsey Fire (2018) –
ql_NLAJlNmLNmplayNLmplqJpqlNm
and resulted in three fatalities.
x Bobcat Fire (2020) – 1JalJUNL
AJlNmLNmplayV_TmplqJpqlNm
and damaging numerous infrastructures in the Angeles National Forest. x Palisades Fire (2025) – 0Nmq]pNLV_mVT_VSVJA_pLNmplqJpVa_A_L]ammaS]VSN Iql_V_TAJlNmLNmplayNLAiilaxV^ApN]ymplqJpqlNmA_Lcausing 12 civilian fatalities. x Eaton Fire (2025) – 0Nmq]pNLV_mVT_VSVJA_pLNmplqJpVa_A_L]ammaS]VSN Iql_V_TAJlNmLNmplayV_TAiilaxV^ApN]ymplqJpqlNmA_Lcausing 17 civilian fatalities. 3UNmNœlNmUVTU]VTUp pUNV_JlNAmV_TSlNkqN_JyA_LV_pN_mVpyaSwV]LœlNmN^iUAmV|V_Tthe urgent need for stronger mitigation and preparedness efforts. 3UN !am _TN]Nm aq_py AlNA UAm NxiNlVN_JNL SNLNlA]]y LNJ]AlNL wV]LœlNm A_L AlNshown in the table below. 3UNlNUAvNINN__ampApNilaJ]A^ApVa_mSalwV]LœlNmV_pUN]AmpœvNyNAlm NLNlA]]yNJ]AlNL:V]LœlNVlN"A_ATN^N_pmmVmpA_JNNJ]AlApVa_V_!amAngeles County from 1/1/2020 to 3/28/2025
Date Incident Name No. Category
1/8/2025 A]VSal_VA:V]LœlNmA_L
Winds
4856 Federal Declaration
1/8/2025 California Eaton Fire 5550 Fire Management Assistance Declaration 1/8/2025 California Hurst Fire 5551 Fire Management Assistance Declaration 1/7/2025 California Palisades Fire 5549 Fire Management Assistance Declaration 12/10/2024 California Franklin Fire 5548 Fire Management Assistance Declaration 9/11/2024 California Bridge Fire 5537 Fire Management Assistance Declaration 10/16/2020 A]VSal_VA:V]LœlNm 4569 Federal Declaration 9/13/2020 California Bobcat Fire 5374 Fire Management Assistance Declaration County of Los Angeles
All-Hazards Mitigation Plan
6.2.5 Probability :VpUmNvNlA]TqAlA_pNNLwV]LœlNmNAJUyNAlpUNilaIAIV]VpyaSwV]LœlNVT_VpVa_V_!am _TN]Nmaq_pyVmTlALqA]]yV_JlNAmV_TLlVvN_]AlTN]yIy J]V^ApN JUA_TNThere is a È JUA_JN aS A œlN aJJqllV_T NAJU yNAl wVpUV_ pUN TNaTlAiUVJ i]A__V_T AlNAVmpalVJA]]y wV]LœlNm aJJqllNL INpwNN_ q_N A_L #avN^INl IqplNJN_p yNAlm UAvNshown a year-laq_L œlN mNAma_ LqN pa UappNl LlVNl Ja_LVpVa_m A_L ^alN V_pN_mNweather variability. !a_TNl Lly iNlVaLm lNLqJNL Uq^VLVpy A_L V_JlNAmNL pN^iNlApqlNm Jaqi]NL wVpUhistoric drought and vegetation die-aSS UAvN JlNApNL JlVpVJA]]y Lly SqN] INLm 3UNmNNvN_pm^A\NNvN_m^A]]VT_VpVa_maqlJNmJAiAI]NaSTN_NlApV_T^A[alwV]LœlNmSanta Ana wV_Lm Ja_pV_qN pa mNlvN Am A ^A[al AJJN]NlA_p Ja_plVIqpV_T palAiVL œlNmilNALA_LmNvNlNœlNINUAvVal:UN_Ja^IV_NLwVpUqlIA_N_JlaAJU^N_pV_paœlNila_N AlNAm pUNmN Ja_LVpVa_m N]NvApN IapU pUN SlNkqN_Jy A_L LNmplqJpVvN_Nmm aSwV]LœlNmProjections from the 2024 THIRA and the LA County Climate Vulnerability Assessment Ja_œl^ pUApwV]LœlNilaIAIV]VpywV]]Ja_pV_qN palVmNq_]NmmmVT_VœJA_pSqN]lNLqJpVa_]A_L qmN i]A__V_T A_L J]V^ApN ALAipApVa_ mplApNTVNm AlN V^i]N^N_pNL AJlamm A]]jurisdictions. The 2024 THIRA estimates that:
x Over 1.2 million residents live in high-risk wildfire zones. x Communities near the Wildland-Urban Interface (WUI) are at the greatest lVm\NmiNJVA]]ypUamNwVpU]V^VpNLNvAJqApVa_laqpNmA_LpUNJJNmmA_LFunctional Needs community. x 9q]_NlAI]Niaiq]ApVa_mV_J]qLV_TmN_Valm]aw-V_Ja^NUaqmNUa]LmA_L iNai]NwVpULVmAIV]VpVNmSAJNUNVTUpN_NLJUA]]N_TNmLqlV_TNvAJqApVa_m.
6.2.6 Vulnerability !am _TN]Nm aq_py SAJNm UVTU wV]LœlN vq]_NlAIV]Vpy LqN pa Vpm NxpN_mVvN:V]L]A_L4lIA__pNlSAJN:4 wVpUavNl^V]]Va_lNmVLN_pmpUAp]VvNV_9NlyHigh Fire Hazard Severity Zones (FHSZs). These communities are particularly susceptible because many Ua^Nm ]AJ\ LNSN_mVI]N miAJN œlN-lNmVmpA_p Ja_mplqJpVa_ al ALNkqApN N^NlTN_Jyaccess. 9q]_NlAI]N iaiq]ApVa_m V_J]qLV_T Iqp _ap ]V^VpNL pa mN_Valm V_LVvVLqA]m wVpULVmAIV]VpVNm ]aw-V_Ja^N UaqmNUa]Lm A_L pUamN LNiN_LN_p a_ N]NJplVJA] ^NLVJA]NkqVi^N_p SAJN mVT_VœJA_p NvAJqApVa_ A_L UNA]pU lVm\m LqlV_T wV]LœlN NvN_pmespecially in WUI communities with limited ingress/egress and high fuel loads.
County of Los Angeles All-Hazards Mitigation Plan
Contextual Overview Very High FHSZ in LRA jurisdiction includes dense hillside residential areas under local œlNAqpUalVpylNmia_mVIV]Vpy3UNmNAlNma^NaSpUN^ampvq]_NlAI]NJa^^q_VpVNmLqNpapNllAV_vNTNpApVa_A_LJa_mplAV_NLN^NlTN_JyAJJNmmlVpVJA]V_SlAmplqJpqlNVmA]maAplVm\wVpUwV]LœlNNxiamqlNpUlNApN_V_TœlNmpApVa_m]AwN_SalJN^N_p SAJV]VpVNm UamiVpA]m qpV]VpVNm plA_mialpApVa_ JallVLalm A_L N^NlTN_JyJa^^q_VJApVa_mympN^mVmlqipVa_ pa pUNmNNmmN_pVA]mNlvVJNmLqlV_TwV]Lœre events can compound vulnerabilities and delay response and recovery. For a better understanding of critical infrastructure at risk please see Appendix C. Total Facilities Affected:
x 9NlyVTU!0: 120 x VTU10: 8 x 9NlyVTU10: 76
:VpUpUNJa_pV_qNLNxiA_mVa_aSLNvN]ai^N_pmV_paœlN-ila_NAlNAmUAmmVT_VœJA_p]yV_JlNAmNLwV]LœlNlVm\"A_yUa^NmV_pUN:4]AJ\ilaiNlLNSN_mVI]NmiAJNA_LœlNlNmVmpA_pIqV]LV_T^ApNlVA]m^A\V_TpUN^iAlpVJq]Al]yvq]_NlAI]NLLVpVa_A]]y]V^Vped evacuation routes in some WUI communities create challenges for emergency lNmia_mNA_LNvAJqApVa_m1plVJpNl|a_V_T]AwmIqV]LV_T lNTq]ApVa_mA_LvNTNpApVa_management policies are the best practices to reduce risk. 14-091%0!1303
0 %:#
Supervisorial District Population in High-0Vm\ Wildfire Zones Percentage of District Population District 1 150,000 12% District 2 75,000 6% District 3 425,000 30% District 4 250,000 20% District 5 500,000 32% County of Los Angeles
All-Hazards Mitigation Plan
Department/
Agency
9NlyVTU1?
!0
VTU1?10 9NlyVTU1?
10
Animal Care and Control
1 0 1
Fire Department 39 1 14 Health Services 1 0 0 Library 7 1 2 LACMA / NHM 1 0 0 %SœJNaSEducation 3 0 3 Other County %SœJNm 0 0 0 -Al\mË0NJlNApVa_ 13 1 12 Public Health 52 4 41 Public :al\m 0 0 0 Sheriff’s Department 3 1 3
:V]LœlNmpUlNApN_NmmN_pVA]V_SlAmplqJpqlNV_J]qLV_T
x Transportation: Damage to roads and bridges affects evacuation and emergency response.
x Utilities-awNl]V_NmTAmiViN]V_NmA_LwApNlV_SlAmplqJpqlNV_J]qLV_T LA^mAlNvq]_NlAI]NpaSVlNLA^ATN
x Emergency Services: Public safety and healthcare facilities near wildfireprone areas face operational disruptions. x Public Services-Al\m]VIlAlVNmmJUaa]mA_LapUNliqI]VJAlNAmJaq]LIN lost or damaged.
County of Los Angeles All-Hazards Mitigation Plan
#NwN^NlTV_TiAppNl_mmqTTNmppUApJ]V^ApNJUA_TN^AyINV_ŔqN_JV_TwV]LœlNlVm\min Los Angeles County through:
x Extending fire seasons: VmpalVJA]]yiNA\SVlNmNAma_aJJqllNLSla^ q_N pa#avN^INlIqpSVlNmAlN_awmpAlpV_TA_Lburning year-round. x Increasing fuel dryness: Higher temperatures and prolonged droughts lNLqJNvNTNpApVa_^aVmpqlN]NvN]m^A\V_TSVlNm^alNV_pN_mN x 0AVmV_TSVlNSlNkqN_JyappNlLlVNlJa_LVpVa_mJa_plVIqpNpa^alN SlNkqN_pVT_VpVa_miAlpVJq]Al]yV_:4AlNAm.
Extent of Exposure
x Total Area Exposed: 243.72 sq mi x Supervisorial Districts (SD) Impacted:
o SD3: 117.95 sq mi (27.29%) o SD5: 95.61 sq mi (3.36%) o SD1: 16.23 sq mi (4.60%) o SD4: 9.10 sq mi (4.27%) o SD2: 4.83 sq mi (1.33%) alAINppNlvVmqA]lNilNmN_pApVa_aSpUVm:V]LœlNA|AlLwVpUV_pUN!aq_pyi]A__V_TAlNAi]NAmNlNSNlN_JNiiN_LVx for several Fire Hazard Severity Zone maps.
6.2.7 Impacts ^iAJpm Sal iAmp œlNm vAly LNiN_LV_T a_ scope and severity V_J]qLV_T pUN A_qAly œlNmV_J]qLV_TpUN-A]VmALNmA_LApa_VlNmlNmq]pNLV_wVLNmilNALLNmplqJpVa_AJlamm !am _TN]Nm aq_py Iql_V_T avNl AJlNm A_L LNmplayV_T ^alN pUA_ mplqJpqlNm Ja^IV_NL wVpU _NAl]y JVvV]VA_ SApA]VpVNm 3UNmN NvN_pm JAqmNLcascading impacts mqJU Am ila]a_TNL iawNl aqpATNm LNTlALNL wApNl ilNmmqlNASSNJpV_T œlNœTUpV_T A_L lNmVLN_pVA] mqii]y A_L avNlwUN]^NL N^NlTN_Jy mNlvVJNmTransportation routes and communications infrastructure were disrupted. a^^q_VpVNm NmiNJVA]]y V_ pUN :V]L]A_L-Urba_ _pNlSAJN :4 NxiNlVN_JNL ^A[alNJa_a^VJ ]ammNm LqN pa pUN LNmplqJpVa_ aS Ua^Nm IqmV_NmmNm A_L iqI]VJ SAJV]VpVNmPost-œlN UA|AlLm ]V\N LNIlVm Ŕawm A_L ]A_Lm]VLNm SqlpUNl Ja^iaq_LNL lNJavNly JUA]]N_TNm wVpU wApNl V_SlAmplqJpqlN Ja_pA^V_ApVa_ A_L sedimentation requiring N^NlTN_Jy lN^NLVApVa_ 3UN mJaiN A_L mNvNlVpy aS pUNmN œlNm q_LNlmJalN pUNincreasing vulnerability of critical infrastructure and the urgent need for enhanced mitigation strategies across high-risk zones.
County of Los Angeles
All-Hazards Mitigation Plan
Problem StatementMany hillside communities within LRA Very High FHSZ zones face critical access and wApNlmqii]yVmmqNmLqlV_TœlNm3UNmNAlNAmaSpN_V_J]qLNATV_TmplqJpqlNmA_L_AllawlaALmJa^i]VJApV_TœlNœTUpV_TA_LNvAJqApVa__vNmp^N_pmV_LNSN_mVI]NmiAJN]aJal JaLNN_SalJN^N_pA_LJa^^q_VpywV]LœlNilapNJpVa_i]A__V_TAlNvVpA]pamAvV_T]VvNmand minimizing losses.6.2.8 Mitigation and Preparedness Los Angeles County is implementing a multi-ATN_JyAiilaAJUpa^VpVTApNwV]LœlNlVm\mKey strategies include:
x Community Wildfire Protection Plans (CWPPs): Strengthening fire prevention measures in high-risk areas.
x Community Preparedness: Educating residents on wildfire readiness pUlaqTUaqplNAJUJA^iAVT_mN^NlTN_JyA]NlpmympN^mA_L_NVTUIalUaaL preparedness programs.
x NSN_mVI]N1iAJN0NkqVlN^N_pmEnforcing brush clearance around structures.
x Enhanced Building Codes: Promoting fire-resistant materials for new developments.
x 9NTNpApVa_"A_ATN^N_pReducing fuel loads through prescribed burns and hazardous tree removal.
x Evacuation Planning: ^ilavV_TJaalLV_ApVa_INpwNN_%"!1 !aA_LapUNl[qlVmLVJpVa_mpaN_mqlNJ]NAlNvAJqApVa_ia]VJVNmA_L procedures.
LLVpVa_A]LNpAV]ma_pUNaq_py¯milaAJpVvNA_La_TaV_TNSSalpmpalNLqJNwV]LœlNlVm\including long-pNl^ i]A__V_T V_SlAmplqJpqlN UAlLN_V_T A_L Ja^^q_Vpy-based V_VpVApVvNmVm]aJApNLV_pUNLNLVJApNLmNJpVa_pVp]NL¬"VpVTApVa_1plApNTVNm
6.2.9 Summary:V]LœlNmlN^AV_a_NaSpUN^ampmVT_VœJA_pUA|AlLmV_!am_TN]Nmaq_pyiamV_TlVm\mpa ]VSN ilaiNlpy A_L JlVpVJA] V_SlAmplqJpqlN 3UN NxiA_mVa_ aS LNvN]ai^N_p V_pa:4AlNAm V_JlNAmV_T œlN mNvNlVpy LqN pa J]V^ApN JUA_TN A_L a_TaV_T JUA]]N_TNm wVph NvAJqApVa_ A_L ^VpVTApVa_ lNkqVlN ilaAJpVvN JaalLV_ApNL NSSalpm AJlamm ATN_JVNm1plN_TpUN_V_TœlNilNvN_pVa_ia]VJVNmV^ilavV_TN^NlTN_JylNmia_mNJaalLV_ApVa_A_L V_pNTlApV_T J]V^ApN ALAipApVa_ ^NAmqlNm AlN NmmN_pVA] pa N_UA_JV_T wV]LœlNresilience for Los Angeles County.
County of Los AngelesAll-Hazards Mitigation Plan
6.3 Earthquake6.3.1 NatureEarthquakes occur due to the sudden release aS N_NlTy V_ pUN AlpUµm Jlqmp TN_NlApV_Tseismic waves that cause ground shaking. 3UNmN NvN_pmaSpN_ plVTTNlNLIy^avN^N_pA]a_TSAq]p]V_NmvAlyV_V_pN_mVpyLNiN_LV_Ta_ SAJpalm mqJU Am ^AT_VpqLN LNipU A_Lproximity to populated areas. In addition to pUNV_VpVA]mUA\V_TmNJa_LAlyUA|AlLmmqJUAmmqlSAJN SAq]pV_T ]VkqNSAJpVa_ ]A_Lm]VLNmtsunamis A_L ASpNlmUaJ\m JA_ walmN_ pUNLA^ATN !am _TN]Nm aq_py ]aJApNL V_ AUVTU]yAJpVvNmNVm^VJlNTVa_SAJNmmVT_VœJA_prisks from thNmN_ApqlA]NvN_pm_NJNmmVpApV_Textensive mitigation efforts and preparedness planning. x The most common effects of
NAlpUkqA\Nm V_J]qLN vVa]N_p mUA\V_TmplqJpqlA]LA^ATNA_LLVmlqipVa_mpaV_SlAmplqJpqlN x 1NJa_LAly NSSNJpm JA_ V_J]qLN Iqp AlN _ap ]V^VpNL pa qpV]VpVNm aqpATNm plASSVJ Ja_TNmpVa_A_LplA_mialpApVa_mympN^mINV_TV^iAmmAI]NA_LA_V_JlNAmNaSSVlNlVm\mSla^Ila\N_TAmA_LwApNl]V_Nm County of Los AngelesAll-Hazard Ms itigation a Pln
County of Los Angeles
All-Hazards Mitigation Plan
x AlpUkqA\NmaJJqlwVpU]Vpp]Npa_awAl_V_T^A\V_TilNiAlNL_NmmNmmN_pVA]Sal minimizing loss of life and property.
6.3.2 Location !am_TN]Nmaq_pyVma_NaSpUN^ampmNVm^VJA]]yAJpVvNlNTVa_mV_pUN4_VpNL1pApNmwith multiple active fault systems capable of generating destructive earthquakes. Major faults include:
x San Andreas Fault – Capable of M 8.0+ x Newport-Inglewood Fault – M 7.4x Malibu Coast Fault System – M 6.7x San Fernando Fault – M 6.6x Santa Monica Fault – M 7.0x Whittier Fault – M 7.2x Sierra Madre Fault – M 6.0-7.0 For a better visual representation of this Earthquake Hazard within LA County planning AlNAi]NAmNlNSNlN_JNiiN_LVx for earthquake fault maps.6.3.3 ExtentJJalLV_Tpa41Na]aTVJA]1qlvNypUNlNAlNpwapyiNmaSNAlpUkqA\N^NAmqlN^N_pmmagnitude (Mw) and intensity (i). Magnitude is a measure of the energy released at the source of the earthquake. Intensity scale help measure impact on people and structures. AlpUkqA\NV^iAJpVmIAmNLa_^AT_VpqLNmJA]NVmAmSa]]awm:
x Great—"wÁx Major—Mw = 7.0 – 7.9x Strong—Mw = 6.0 – 6.9x Moderate—Mw = 5.0 – 5.9x Light—Mw = 4.0 – 4.9x Minor—Mw = 3.0 – 3.9x Micro—Mw < 3 County of Los AngelesAll-Hazards Mitigation Plan
"aLVœNL"Nlcalli Intensity 1JA]NVmSla^ pa;wUVJU lNSNlm Am_apSN]p A_L; Amextreme.
Figure 6.3.1 "aLVœNL"Nlcalli Intensity Scale
Over 75% of unincorporated Los Angeles County is at risk for severe to extreme shaking in a future earthquake. 3UNlNTVa_µmLN_mNqlIA_N_vVla_^N_pJa^IV_NLwVpUATV_TV_SlAmplqJpqlNV_JlNAmNmthe likelihood of extensive damage and prolonged recovery times. Faults running beneath critical V_SlAmplqJpqlNJallVLalmV_J]qLV_TSlNNwAymA_LiawNlTlVLmiamNAmVT_VœJA_ppUlNAppaiqI]VJmASNpyA_LNJa_a^VJmpAIV]Vpy of the planning area.
County of Los Angeles
All-Hazards Mitigation Plan
6.3.4 History !am_TN]Nmaq_pyUAm A]a_TUVmpalyaSLNmplqJpVvNNAlpUkqA\NmwVpUma^NaS pUN earliest recorded events dating back to the early 19th century. The San Juan Capistrano AlpUkqA\N aS " wAm A^a_T pUN œlmp pa IN LaJq^N_pNL JAqmV_T pUN collapse aS"VmmVa_1A_ qA_AiVmplA_aA_LlNmq]pV_TV_SApA]VpVNm%vNlpUNyNAlmpUN Jaq_py UAm NxiNlVN_JNL _q^Nlaqm mVT_VœJA_p kqA\Nm V_J]qLV_T pUN LNvAmpApV_T alp3N[a_AlpUkqA\N" pUN1A_Nl_A_LaAlpUkqA\N" A_Lthe infamous #alpUlVLTNAlpUkqA\N" wUVJUJAqmNLIV]]Va_mV_LA^ATNm and led to widespread infrastructure failures. There have been no federal declarations or state proclamations for earthquakes V_pUN]AmpœvNyNAlm "A[alAlpUkqA\NmV_!am_TN]Nmaq_py– Present) Date Magnitude Name / Location Notable Impact
NJN^INl1812
7.5 San Juan Capistrano Earthquake
Destroyed Mission San Juan AiVmplA_a\V]]NLiNai]N NJN^INl1812
7.1 West Ventura Earthquake
AqmNLmVT_VœJA_pmUA\V_TV_Southern California.
A_qAly
7.9 Fort Tejon Earthquake Largest earthquake on the San _LlNAmAq]plqipqlNL miles. q]y
7.5 Kern County Earthquake Strong shaking felt in Los _TN]Nm^A[alLA^ATNpa A\NlmœN]LNIlqAly 6.6 San Fernando Earthquake LNApUm¸
^V]]Va_V_ LA^ATNmJa]]AimNaS9NpNlA_m Hospital. %JpaINl 5.9 Whittier Narrows Earthquake LNApUmV_[qlVNm¸ million in damages. NIlqAly1990 5.7 Upland Earthquake V_[qlVNm¸^V]]Va_V_ damages.
County of Los Angeles All-Hazards Mitigation Plan
6.3.5 Probability Trends in Seismic Activity Over 163 earthquakes of M 5.0 or greater have been recorded in Southern California since 1812. 3UN1A__LlNAmAq]plN^AV_mpUNTlNApNmpmNVm^VJUA|AlLwVpUA ÈJUA_JNaSA_"6.7+ event in the next 30 years. qpqlNAlpUkqA\N%JJqllN_JNThe U.S. Geological Survey (USGS) estimates the following probabilities for a major earthquake in Los Angeles County in the next 30 years:
x 60% chance of an M 6.7+ earthquake x 46% chance of an M 7.0+ earthquake x 31% chance of an M 7.5+ earthquake
6.3.6 Vulnerability 3UN Jaq_py¯m vq]_NlAIV]Vpy pa NAlpUkqA\Nm NxpN_Lm INya_L iUymVJA] V_SlAmplqJpqlNASSNJpV_TVpmlNmVLN_pmA_LNmmN_pVA]mNlvVJNm%]LNlIqV]LV_TmiAlpVJq]Al]yq_lNV_SalJNLmasonry and soft-mpaly mplqJpqlNm AlN Ap UVTU lVm\ aS Ja]]AimN iamV_T mVT_VœJA_p q_N 5.6
Sierra Madre Earthquake
LNApU½V_[qlVNm¸million in damages.
A_qAly 6.7 Northridge Earthquake
LNApUmV_[qlVNm¸ IV]]Va_V_LA^ATNmSlNNwAym collapsed. q]y 5.5 Chino Hills Earthquake V_[qlVNm^V_almplqJpqlA] damage. "AlJU 5.1 La Habra Earthquake NwV_[qlVNm¸^V]]Va_V_ damages. q]y 7.1 Ridgecrest Earthquake Widespread damage in 1aqpUNl_A]VSal_VA infrastructure impacts.
County of Los Angeles
All-Hazards Mitigation Plan
dangers to residents and businesses. 1NVm^VJlNplaœppV_TNAl]ywAl_V_TmympN^mA_LmplVJpNl IqV]LV_T JaLNm UAvN V^ilavNL lNmV]VN_JN Iqp vulnerabilities remain in older structures and critical infrastructure. lVpVJA]_SlAmplqJpqlNAp0Vm\ x Highways, bridges, and transportation routes: A major earthquake could mNvNlN]yLVmlqip^aIV]Vpyshipment of goods and services while also delaying emergency response and evacuations. "A[alUVTUwAymmqJUAmIqp_ap]V^VpNLto the I- -41----
-A_L-105 could be impacted.
x Energy grids and water system: Disruptions could leave millions without power and clean water.
x Hospitals and emergency services:
UamiVpA]mA_LœlNmpApVa_mV_pUN
Los Angeles County could suffer functional impairments. x Unreinforced masonry and soft-story buildings: Many older structures are highly susceptible to collapse during strong ground shaking. aq_py1iNJVœJlVpVJA]AJV]VpVNmSSNJpNL
x Fire Department: 314 facilities (93.18%) x Public Works: 201 facilities (87.39%) x Health Services: 56 facilities (85.71%) x Public Health: 37 facilities (92.50%) x Libraries: 78 branches (89.66%) x Parks: 179 (97.79%) x Education: 70 (85.37%) !am_TN]Nmaq_py]VNmAppUNV_pNlmNJpVa_aS^q]pVi]N^A[alSAq]p]V_NmV_J]qLV_TpUN1A__LlNAmAq]pJJalLV_TpapUNUA|AlL^AplVxpUNlVm\aSvVa]N_pTlaq_LmUA\V_TVmilNvA]N_p Jaq_pywVLN iAlpVJq]Al]y V_ qlIA_ JN_pNlm A_L lNTVa_m wVpU JlVpVJA]infrastructure. The potential consequences of violent seismic shaking include wVLNmilNAL mplqJpqlA] LA^ATN LVmlqipVa_ aS mNlvVJNm NJa_a^VJ ]ammNm A_L Uq^A_casualties. -aiq]ApVa_mAp0Vm\ x The THIRA estimates over 2 ^V]]Va_lNmVLN_pmJaq]LINmVT_VœJA_p]yV^iAJpNLV_ A^A[almNVm^VJNvN_piAlpVJq]Al]ypUamNV_UVTU-risk seismic zones.
County of Los Angeles All-Hazards Mitigation Plan
x People Experiencing Homelessness (PEH) populations: ½ unhoused
individuals in Los Angeles County live in areas at risk of violent shaking. x Low-income and individuals with access and functional needs (AFN): For more details on impacted population please see Section 5.
Extent of Exposure
x Total Area Exposedmk^Vx Supervisorial Districts (SD) Impacted:
o SD5
mk^V
È o SD3: 379.41 sq mi (87.99%) o SD1: 349.17 sq mi (98.95%) o SD2: 362.95 sq mi (99.99%) o SD4: 210.92 sq mi (99.10%)
6.3.7 Impacts Los Angeles County has a long history of experiencing damaging earthquakes due to Vpm]aJApVa_A]a_T^q]pVi]NAJpVvNSAq]pmympN^mV_J]qLV_T pUN1A__LlNAm#Nwialp-_T]NwaaLA_L:UVppVNlSAq]pmVmpalVJNAlpUkqA\NmmqJU Am pUN1A_Nl_A_La(M6.6) and 1994 Northridge (M6.7) events caused catastrophic losses. The San Nl_A_La NAlpUkqA\N lNmq]pNL V_ LNApUm pUN Ja]]AimN aS UamiVpA] mplqJpqlNm A_LavNl ¸
^V]]Va_ V_ LA^ATNm wUV]N pUN #alpUlVLTN NAlpUkqA\N JAqmNL LNApUm^alN pUA_V_[qlVNmA_LA_NmpV^ApNL¸IV]]Va_V_NJa_a^VJ]ammNmV_J]qLV_Twidespread infrastructure failures such as collapsed freeways and damaged utility systems. Impacts from future major seismic events are projected to be even more severe due to iaiq]ApVa_ LN_mVpy ATV_T V_SlAmplqJpqlN A_L V_JlNAmV_T LNvN]ai^N_p V_ mNVm^VJA]]yvulnerable areas. Over 75% of unincorporated Los Angeles County is at risk of severe to extreme ground shaking. Current estimates suggest that a large-magnitude NAlpUkqA\NJaq]LLVmi]AJNqipa^V]]Va_iNai]NV_[qlNal\V]]pUaqmA_LmA_LlNmq]pV_avNl¸IV]]Va_V_Ja^IV_NLNJa_a^VJ]ammNmV_J]qLV_T¸IV]]Va_V_ilaiNlpyLA^ATNA_L¸IV]]Va_V_IqmV_NmmV_pNllqipVa_m County of Los Angeles
All-Hazards Mitigation Plan
3UN aq_py¯m JlVpVJA] mympN^m iawNl wApNl plA_mialpApVa_ UNA]pUJAlN A_LJa^^q_VJApVa_mAlNNmiNJVA]]yvq]_NlAI]N^A[alNAlpUkqA\NJaq]LV^iAVlqipa UamiVpA]m A_L œlN mpApVa_m A_L LVmlqip JlVpVJA] V_SlAmplqJpqlN Sal ^V]]Va_mPopulationm wVpU UNVTUpN_NL vq]_NlAIV]Vpy V_J]qLN pUN ½ iNai]N NxiNlVN_JV_TUa^N]Nmm_Nmm pUamN wVpU AJJNmm A_L Sq_JpVa_A] _NNLm A_L lNmVLN_pm aS a]LNlunreinforced masonry and soft-story structures. :VpUaqp mqSœJVN_p ^VpVTApVa_ A SqpqlN NAlpUkqA\N Jaq]L lNmq]p V_ JAmJALV_T SAV]qlNmacross multiple sectors and prolong the County’s recovery for years. These risks UVTU]VTUp pUN qlTN_Jy Sal Ja_pV_qNL V_vNmp^N_p V_ mNVm^VJ lNplaœppV_T mplVJpNlenforcemN_p aS IqV]LV_T JaLNm NxiA_LV_T mpApNwVLN NAl]y wAl_V_T mympN^m A_L equitable preparedness programs targeting at-risk vulnerable populations. x Casualties and injuries: NiN_LV_Ta_pUNpV^NaSLAyA_L]aJApVa_pUaqmA_Lm could be injured or killed in a severe earthquake.
x Economic disruption: mVT_VœJA_pNAlpUkqA\NJaq]LUA]pIqmV_NmmaiNlApVa_m LA^ATNmqii]yJUAV_mA_LSalJNpUaqmA_LmV_paq_N^i]ay^N_p x Housing displacement: _NmpV^ApNL^V]]Va_lNmVLN_pmJaq]LINLVmi]AJNL with tens of thousands requiring emergency sheltering.
Economic Impact A major earthquake in Los Angeles County Jaq]LlNmq]pV_avNl¸IV]]Va_V_NJa_a^VJ]ammNm wVpUApapA]aS¸plV]]Va_-dollar exposure. Losses can include:
x ¸IV]]Va_V_IqmV_NmmV_pNllqipVa_mx ¸
IV]]Va_V_]ampNJa_a^VJAJpVvVpyx ¸IV]]Va_V_ilaiNlpyLA^ATNm Problem Statement The pervasive exposure of Los Angeles County to violent earthquake shaking presents AmympN^VJpUlNAppaiqI]VJmASNpyNJa_a^VJmpAIV]VpyA_LNmmN_pVA]mNlvVJNm#NAl]yA]]major departments and infrastructure elements are located within high-shaking hazard |a_Nm 3UN NxpN_mVvN lNAJU AJlamm A]] œvN 1qiNlvVmalVA] VmplVJpm 1 A^i]VœNm pUNJUA]]N_TN UVTU]VTUpV_T pUN qlTN_p _NNL Sal lNplaœppV_T iqI]VJ NLqJApVa_ ilNiAlNL_NmmilaTlA^m A_L lNmV]VN_pLNmVT_ia]VJVNmAV]qlN pa ALLlNmm pUVm UA|AlLcould lead to catastrophic loss of life and functionality in the event of a major seismic event.
County of Los Angeles All-Hazards Mitigation Plan
6.3.8 Mitigation and Preparedness Efforts to reduce earthquake risks in Los Angeles County include strengthening IqV]LV_T JaLNm N_UA_JV_T N^NlTN_Jy ilNiAlNL_Nmm A_L lNplaœppV_T vq]_NlAI]Nstructures. NyNSSalpmpa^VpVTApNNAlpUkqA\NlVm\mV_J]qLN x 1plN_TpUN_V_TIqV]LV_TJaLNmA_LN_SalJV_TlNplaœppV_T]Awmx Upgrading critical infrastructure x Expanding public education and early warning systems x Enhancing emergency response planning
y ilaAJpVvN]y V^i]N^N_pV_T pUNmN ^NAmqlNm !am _TN]Nm aq_py AV^m pa lNLqJNJAmqA]pVNmV_SlAmplqJpqlNLA^ATNA_LNJa_a^VJ]ammNmV_SqpqlNmNVm^VJNvN_pm1NVm^VJ0NplaœppV_T-laTlA^m x 1aSpmpalylNplaœpilaTlA^: Mandates seismic upgrades for older apartment buildings.
x Non-LqJpV]N Ja_JlNpN IqV]LV_T lNplaœpm: Strengthens older commercial and residential structures.
x amiVpA]m A_L N^NlTN_Jy SAJV]VpVNm lNplaœppV_T: Ensures critical services remain operational post-earthquake.
-a]VJyA_L0NTq]Apaly"NAmqlNm
x Assembly Bill (AB) 1857: Strengthens building standards for multi-story structures.
x AB 2681: Requires cities and counties to inventory vulnerable buildings. x Updated California Building Code (CBC): Enforces stricter seismic design criteria for new construction.
x Public Education: 3NAJUV_T pa lai avNl A_L a]L %_ pUN UaqmNUa]L ilNiAlNL_NmmJUNJ\]VmpNLqJApNlNmVLN_pma_N^NlTN_JylNmia_mNlNplaœppV_Tand disaster preparedness. x Early Warning/ ShakeAlert System: Provides real-time earthquake early warnings to residents via mobile alerts and public messaging.
x Public earthquake drills: Annual Great California ShakeOut encourages preparedness.
County of Los Angeles
All-Hazards Mitigation Plan
6.3.9 Summary!am_TN]Nm aq_py lN^AV_m Ap UVTU lVm\Sal LNvAmpApV_T NAlpUkqA\Nm wVpU mJVN_pVœJila[NJpVa_mV_LVJApV_TAmpla_T]V\N]VUaaLaSAmVT_VœJA_pmNVm^VJNvN_pV_pUNJa^V_TLNJALNm 3UN lNTVa_ UAm NxiNlVN_JNL _q^Nlaqm UVmpalVJ NAlpUkqA\Nm A_L pUNpotential for future large-scale disasters remains ever-present. While advances in N_TV_NNlV_T N^NlTN_Jy ilNiAlNL_Nmm A_L ^VpVTApVa_ NSSalpm UAvN V^ilavNLlNmV]VN_JN JUA]]N_TNm iNlmVmp iAlpVJq]Al]y lNTAlLV_T ATV_T V_SlAmplqJpqlN A_Lvulnerable communities. ConpV_qNLV_vNmp^N_pmV_lNplaœppV_TiqI]VJNLqJApVa_A_LNAl]ywAl_V_T mympN^mwV]]IN JlVpVJA]V_^V_V^V|V_T JAmqA]pVNm NJa_a^VJ]ammNm A_Lrecovery challenges in future earthquakes.
County of Los AngelesAll-Hazards Mitigation Plan
County of Los AngelesAll-Hazards Mitigation Plan6.4 Extreme Heat6.4.1 NatureExtreme heat refers to prolonged periods of UVTU pN^iNlApqlNm aSpN_ AJJa^iA_VNL IyUVTUUq^VLVpyiamV_TmVT_VœJA_pUNA]pUlVm\msuch as heat exhaustion and heat stroke. The urban heat island (UHI) NSSNJp ilNvA]N_p V_LN_mN]yIqV]pAlNAm]V\N!am_TN]Nmaq_pyV_pN_mVœNm pUNmN Ja_LVpVa_m Iy AImalIV_Tand retaining heat. The changing climate conditions through time in the region exacerbate for the rising of daily temperature and for the increasing of extreme heat days in the County. This leads pa UNA]pU VmmqNminJlNAmN N_NlTy LN^A_L A_L mplAV_ a_infrastructure.6.4.2 LocationLos Angeles County is particularly susceptible to extreme heat due to its diverse geography and urban density. ]]aS!am_TN]Nmaq_py^AyNxiNlVN_JNNxplN^NUNApnonetheless i_]A_L lNTVa_m V_J]qLV_T pUN vA]]Nym A_L UVTU LNmNlp AlNAm NxiNlVN_JN County of Los Angeles
All-Hazards Mitigation Plan
higher temperatures compared to coastal areas. The urban heat island (UHI) effect can increase temperatures in cities and developed areas than the less developed areas.Urban centers with extensive concrete and asphalt surfaces further amplify heat lNpN_pVa_Ja_plVIqpV_TpaN]NvApNLpN^iNlApqlNm and increased UHI effect in the county.6.4.3 ExtentThe severity of heat events in Los Angeles County has been increasing. Projections V_LVJApNAmVT_VœJA_plVmNV_pUNSlNkqN_JyA_LV_pN_mVpyaSUNApwAvNmwVpUV_]A_LAlNAmpotentially experiencing temperatures exceeding 110°F. The urban heat island effect JA_ JAqmN qlIA_ AlNAm pa IN mNvNlA] LNTlNNm wAl^Nl pUA_ pUNVl lqlA] Jaq_pNliAlpmexacerbating the impact of heat waves. The chart below shows the levels of heat wave impacts qmNL pa ^NAmqlN UNApwAvN mNvNlVpy NAp0Vm\ A_ NxiNlV^N_pA] ^NAmqlN developeLIy pUN#:1V_Ja]]AIalApVa_wVpU pUNJ]AmmVœNmUNApNvN_pmIy pUNVlimpact on human health. It ranges from Green (0) which is little or no risk to Magenta wUVJU^NA_mNxplN^NUNApwVpU_aavNl_VTUplN]VNS Category Figure 6.4.1 0Vm\aSNAp-0N]ApNL^iAJpm
lNN_
0 Little to no risk from expected heat.
Yellow
1 Minor - This level of heat affects primarily those individuals extremely mN_mVpVvNpaUNApNmiNJVA]]ywUN_aqpLaalmwVpUaqpNSSNJpVvNJaa]V_TA_Laladequate hydration.
Orange
2 Moderate - This level of heat ASSNJpm ^amp V_LVvVLqA]m mN_mVpVvN pa UNApespecially those without effective cooling and/or adequate hydration. Impacts possible in some health systems and in heat-sensitive industries. 0NL
3 Major - This level of heat affects anyone without effective cooling and/or ALNkqApN UyLlApVa_ ^iAJpm ]V\N]y V_ ma^N UNA]pU mympN^m UNAp-sensitive industries and infrastructure.
Magenta
4 Extreme - This level of rare and/or long-duration extreme heat with little to no overnight relief affects anyone without effective cooling and/or adequate UyLlApVa_^iAJpm]V\N]yV_^ampUNA]pUmympN^mUNAp-sensitive industries and infrastructure.
EĂƟŽŶĂůtĞĂƚŚĞƌ^ĞƌǀŝĐĞ ;Et^Ϳ, 2024
County of Los AngelesAll-Hazards Mitigation Plan
qTqmpINV_TpUNUappNmp^a_pUaSpUNyNAlpUAppUNi]A__V_TAlNANxiNlVN_JNmpUNFigure 6.4.2 IN]awmUawmpUNAvNlATNUVTUpN^iNlApqlNSalqTqmpV_!am_TN]Nmaq_pymmUaw_pUNpN^iNlApqlNvAlVNmIy]aJApVa_IqplN^AV_mUVTUNlthan average monthly temperature.
Figure 6.4.2͕DĞĂŶDĂdždĞŵƉĞƌĂƚƵƌĞĨŽƌƵŐƵƐƚϮϬϮϰ͕EĂƟŽŶĂůtĞĂƚŚĞƌ^ĞƌǀŝĐĞ
6.4.4 History
NJAqmN aS pUN JUA_TV_T J]V^ApN Ja_LVpVa_m A_L pUN TNaTlAiUVJA] ]aJApVa_ !amAngeles County has been experiencing extreme heat waves in the past years. It has a UVmpalyaSNxplN^NUNApNvN_pmwVpUpN^iNlApqlNmSlNkqN_p]ylNAJUV_TLNTlNNmal^alNNmiNJVA]]yLqlV_TpUNmq^^Nl^a_pUm_ma^NJAmNmpUNmNNxplN^NUNApNvN_pmare record-breaking heat waves surpassing their all-time highs. Extreme Heat events include:
x August 2020: mNvNlNUNApwAvN]NLpawVLNmilNALiawNlaqpATNmASSNJpV_T _NAl]y
lNmVLN_pm
County of Los Angeles
All-Hazards Mitigation Plan
x September 2020: The San Fernando Valley recorded a record high temperature of 121°F.
x August 2022: A record-breaking heatwave in late summer exceeded 100°F x September 2024: A severe September heatwave pushed temperatures 10- ÑAIavN_al^A]UVppV_TÑV_!a_T
NAJU
The History of Extreme heat events highlight the increasing trend of extreme heat occurrences in the region. There have been no federal declarations or state ilaJ]A^ApVa_m Sal NxplN^N UNAp V_ pUN ]Amp œvN yNAlm Even though there were no LNJ]AlNL NxplN^N UNAp N^NlTN_JVNm pUN Jaq_py UAm VmmqNL mNvNlA] UNAp A]Nlpm A_Ltaken measures to protect residents from the impacts of heat waves during these periods.
6.4.5 ProbabilityxplN^NUNApNvN_pmAlNA_A__qA]aJJqllN_JNV_!am_TN]Nmaq_pypUaqTUmNvNlVpyaSmqJUNvN_pmvAlyiNlyNAlIAmNLa_apUNlJa_LVpVa_mmqJUAm]#Vño. Climate models project a substantial increase in the likelihood of extreme heat events in Los Angeles County. By mid-JN_pqlypUNJaq_pyJaq]LNxiNlVN_JN^alNpUA_œvN^A[alUNApwAvNmA__qA]]y wVpU ma^N ^aLN]m mqTTNmpV_T qi pa pN_Sa]L V_JlNAmNm V_ SlNkqN_Jy 3UVmheightened probability necessitates proactive mitigation and adaptation strategies.
Figure 6.4.3, ǀĞƌĂŐĞdĞŵƉĞƌĂƚƵƌĞϭϵϬϬ-2025, NOAA, NCEI, 2025.
6.4.6 VulnerabilityxplN^N UNAp iamNm A mVT_VœJA_p A_L TlawV_T pUlNAp pa !am_TN]Nm aq_py wUNlNlVmV_TpN^iNlApqlNmqlIA_UNApVm]A_LmA_LwVLNmilNALmaJVA]vq]_NlAIV]VpyV_pNlmNJp3UamN^ampAplVm\V_J]qLNpUNN]LNl]y]aw-V_Ja^NUaqmNUa]Lm]AJ\V_TAVlJa_LVpVa_V_T County of Los AngelesAll-Hazards Mitigation Plan
iNai]NNxiNlVN_JV_TUa^N]Nmm_Nmm- V_LVvVLqA]mwVpUAJJNmmA_LSq_JpVa_A]_NNLm# A_LpUNaq_py¯m]AlTNiaiq]ApVa_aSaqpLaalA_L_a_-air-conditioned indoor workers. Infrastructure is also strained N]NJplVJVpy LN^A_L miV\Nm LqlV_T UNApwAvNmoften overwhelming the power grid and triggering outages. Water systems experience V_JlNAmNLLN^A_LA_LNvAialApVa_]ammNmwUV]NlaALwAymA_LlAV]]V_NmAlNmqI[NJppabuckling or operational delays. In recent yNAlm!am_TN]Nmaq_pyUAmNxiNlVN_JNLseverNJa_mNkqN_JNmSla^ila]a_TNLUNApNvN_pmlNV_SalJV_TpUNqlTN_p_NNLSalUNApresilience strategies targeting both people and critical services.
Los Angeles County–1iNJVœJ^iAJpmA_LApA
x lNmVLN_pm NxiNlVN_JNL iawNl aqpATNm LqlV_T pUN qTqmp heatwave.
x ÈaSpUNaq_py¯m^V]NmaSUVTU-voltage transmission lines are exposed to moderate to high extreme heat risk.
x ^V]]Va_ lNmVLN_pm AlN Ja_mVLNlNL UVTU]y vq]_NlAI]N LqN pa ATN V_Ja^N LVmAIV]VpyalJUla_VJUNA]pUJa_LVpVa_m
x %vNlaqpLaalwal\NlmAlNApN]NvApNLlVm\SalUNAp-related illness and injury.
x Thousands of heat-related emergency visits occurred during multi-day heat events in 2020 and 2022especially in neighborhoods with limited shade and high surface temperatures. x 50+ cooling centers have been activated across the County during recent heatwaves to support at-risk populations.
x VTU UNAp Ja_plVIqpNm pa walmN_NL AVl kqA]Vpy V_JlNAmNL wV]LœlN m^a\N NxiamqlN A_L NJa_a^VJ ]ammNm LqN pa V_SlAmplqJpqlN LA^ATN ilaLqJpVvVpyLNJ]V_NA_LlVmV_TUNA]pUJAlNJampm
6.4.7 Impacts!am _TN]Nm aq_py UAm SAJNL mVT_VœJA_p A_L TlawV_T V^iAJpm Sla^ NxplN^NUNApwAvNmavNlpUNiAmppwaLNJALNm_qTqmpAila]a_TNLUNApwAvNJAqmNLla]]V_T I]AJ\aqpm ASSNJpV_T _NAl]y Jqmpa^Nlm avNlwUN]^NL pUN mpApN¯mN]NJplVJA] TlVL A_LSarced the activation of emergency conservation protocols. That mA^N mq^^Nl pUN 1A_ Nl_A_La 9A]]Ny UVp Ñ ]NALV_T pa wVLNmilNAL mplAV_ a_ County of Los Angeles
All-Hazards Mitigation Plan
HVAC systems and increased emergency room visits for heat-related illnesses. The 2022 and 2024 heatwaves brought similar conditions—temperatures over 100°F across pUNlNTVa_]NLpa]aJA]V|NLplA_mSal^NlSAV]qlNmAmiUA]pIqJ\]V_TA_LmplAV_a_wApNldelivNlymympN^mLqNpaN]NvApNLLN^A_LqlV_TpUNmNNvN_pmaqpLaalwal\NlmpUNN]LNl]yA_L]aw-income residents without access to cooling systems were among the ^amp ASSNJpNL Ja_a^VJ AJpVvVpy wAm LVmlqipNL wVpU lNialpm aS IqmV_Nmm J]amqlNmservice delaymA_LV_JlNAmNLUNA]pUJAlNJampm_!a_T NAJUlNAJUNLAlNJalLÑJAqmV_TAmiV\NV_N]NJplVJVpyLN^A_LA_LplVTTNlV_TN^NlTN_JyN_NlTyA]Nlpmacross Southern California. Heat-related deaths and hospitalizations have also trended qiwAlL iAlpicularly in neighborhoods with low tree canopy and high impervious surfaces. These impacts underscore the need for resilient infrastructure and targeted adaptation strategies to safeguard health and essential services.6.4.8 Mitigation and Preparedness The most effective way to reduce the negative impacts of an extreme heat event is to develop a comprehensive heat response plan that has individual strategies to effectively manage heat waves during peak seasons of the year. The plan might include SalNJAmpV_TA_L^a_VpalV_TNLqJApVa_A_LAwAlN_NmmA_LUNApwAvNlNmia_mN. To address extreme heat!am_TN]Nmaq_pyUAmV^i]N^N_pNLmNvNlA]^NAmqlNm x Cooling Centers: Establishment of air-conditioned public spaces where residents can seek relief during heatwaves. These centers are facilities such as ]VIlAlVNm Ja^^q_Vpy JN_pNlm A_L mN_Val JN_pNlm 0NmVLN_pm JA_ ]aJApN pUN nearest cooling center using resources provided by the county. Additional resources can be found at ŚƚƚƉƐ͗ͬͬƌĞĂĚLJ͘ůĂĐŽƵŶƚLJ͘ŐŽǀͬŚĞĂƚͬ x 4lIA_ lNN_V_T _VpVApVvNm -laTlA^m AV^NL Ap V_JlNAmV_T TlNN_ miAJNm i]A_pV_T plNNm A_L JlNApV_T iAl\m pa ilavVLN mUALN A_L lNLqJN A^IVN_ptemperatures. These efforts help mitigate the urban heat island effect. x Public Awareness Campaigns: Educational initiatives to inform residents about UNAp lVm\milNvN_pVa_ mplApNTVNm A_L lNmaqlJNm AvAV]AI]NLqlV_TNxplN^NUNApNvN_pm3UNmNJA^iAVT_mN^iUAmV|N pUNV^ialpA_JNaSUyLlApVa_lNJaT_V|V_Theat-lN]ApNLV]]_Nmmmy^ipa^mA_LqpV]V|V_TJaa]V_g centers. x
qV]LV_TaLNmA_L0NTq]ApVa_m Incorporation of heat-mitigating designs and ^ApNlVA]m V_ _Nw Ja_mplqJpVa_m A_L lNplaœpm mqJU Am Jaa] laaSm A_L lNŔNJpVvN County of Los Angeles All-Hazards Mitigation Plan
iAvN^N_pm pa lNLqJN UNAp AImalipVa_ 3UNmN ^NAmqlNm AV^ pa ]awNl V_Laaltemperatures and decrease reliance on air conditioning. 3UNmN mplApNTVNm AlN LNmVT_NL pa lNLqJN UNAp NxiamqlN ilapNJp vq]_NlAI]Niaiq]ApVa_mA_LN_UA_JNJa^^q_VpylNmV]VN_JNATAV_mpNxplN^NUNApNvN_pm
6.4.9 Summary Extreme heat iamNmATlawV_TpUlNAppa!am_TN]Nmaq_pywVpUV_JlNAmV_TSlNkqN_Jyand intensity of heat waves exacerbated by urban heat island (UHI) effects. Understanding these impacts of extreme heat A_L pA\V_T AiilailVApN ilNJAqpVa_mresidents of Los Angeles County can protect themselves and their communities from this growing climate hazard. 3UN Jaq_py UAm q_LNlpA\N_ vAlVaqm ^VpVTApVa_ NSSalpmV_J]qLV_T pUN NmpAI]VmU^N_p aS Jaa]V_T JN_pNlm qlIA_ TlNN_V_T ila[NJpm iqI]VJNLqJApVa_ JA^iAVT_m A_Lthe implementation of heat-conscious building practices. %_TaV_TALAipApVa_A_LilaAJpVvNi]A__V_TAlNNmmN_pVA]pamASNTqAlLiqI]VJUNA]pUV_SlAmplqJpqlNA_LpUNN_vVla_^N_pSla^pUNALvNlmNNSSNJpmaSNxplN^NUNAp County of Los Angeles
All-Hazards Mitigation Plan
6.5 Drought
6.5.1 Nature
Drought is a prolonged period of belowaverage precipitation that leads to water mUalpATNm V^iAJpV_T ATlVJq]pqlN NJamympN^mand urban water supplies. Unlike other natural LVmAmpNlmLlaqTUpLNvN]aimTlALqA]]y^A\V_TVp LVSœJq]p pa ilNLVJp A_L ^VpVTApN _ !am_TN]Nmaq_pyLlaqTUpmAlNAlNJqllV_TVmmqNdue to the region’s arid climate and dependence on imported water supplies.laqTUpmNvNlVpyVmLNpNl^V_NLIyVpmLqlApVa_V_pN_mVpy TNaTlAiUVJ NxpN_p A_L wApNldemand. Climate change is exacerbating these SAJpalm ]NALV_T pa UappNl pN^iNlApqlNmlNLqJNL ilNJViVpApVa_ A_L V_JlNAmNLevaporation rates. :V]LœlNmAlNalso projected to increase in frequency and intensity during drought season.3UNlNAlNSaqlJa^^a_J]AmmVœJApVa_maSLlaqTUp x Meteorological Drought: A prolonged period of below-normal precipitation.
County of LosAngelesAll-HazardsMitigation Plan
County of Los AngelesAll-Hazards Mitigation Plan
x Hydrological Drought: A reduction in surface and groundwater levels due to ila]a_TNLilNJViVpApVa_LNœJVpm
x Agricultural Drought: A lack of soil moisture that affects crop growth and livestock sustainability.
x Socioeconomic Drought: When water shortages impact drinking water mqii]VNmmA_VpApVa_iqI]VJmNlvVJNmA_LNJa_a^VJAJpVvVpVNm
6.5.2 LocationDrought is regional in nature and typically affects the entire Los Angeles County planning area. Given the county’s reliance on imported water from the Sierra Nevada m_awiAJ\A_L pUNa]alALa0VvNl lNLqJNLAvAV]AIV]VpyaS pUNmNmaqlJNmmVT_VœJA_p]yincreases vulnerability. 6.5.3 Extent laqTUpVmAlNJqllV_T_ApqlA]UA|AlLpUApJA_mNvNlN]yV^iAJpATlVJq]pqlNwApNlmqii]yNJamympN^m A_L Ja^^q_VpVNm 3a ^a_Vpal A_L Ja^^q_VJApN LlaqTUp Ja_LVpVa_mAJlamm pUN 4_VpNL 1pApNm pUN #ApVa_A] laqTUp "VpVTApVa_ N_pNl #" V_partnership with the U.S. Department of Agriculture (USDA) and the National Oceanic A_L p^amiUNlVJ L^V_VmplApVa_ #% ilaLqJNm wNN\]y 41 laqTUp "a_Vpal ^Aim3UNmN^Aim JApNTalV|NLlaqTUp Ja_LVpVa_mV_paœvN]NvN]mIAmNLa_V_pN_mVpyLqlApVa_ A_L V^iAJp a_ vAlVaqm mNJpalm V_J]qLV_T ATlVJq]pqlN wApNl lNmaqlJNm A_Lpublic health.AJU LlaqTUp JApNTaly lNŔNJpm A LVSSNlN_p ]NvN] aS mNvNlVpy Sla^ mUalp-term dry Ja_LVpVa_mpUAp^Aym]awJlaiTlawpUpa]a_T-pNl^wVLNmilNALwApNlmUalpATNmpUAplNkqVlNN^NlTN_JylNmia_mN3UNmNJ]AmmVœJApVa_mUN]iLNJVmVa_-^A\NlmSAl^NlmA_Lwater managers respond appropriately to emerging or ongoing drought conditions.See Figure 6.5.1 below for more information.
County of Los Angeles
All-Hazards Mitigation Plan
Drought Categories and Associated Impacts:
CATEGORY DESCRIPTION POSSIBLE IMPACTS
D4 EXCEPTIONAL
DROUGHT
x
džĐĞƉƟŽŶĂůĂŶĚǁŝĚĞƐƉƌĞĂĚĐƌŽƉͬƉĂƐƚƵƌĞůŽƐƐĞƐx ƌŝƟĐĂůƐŚŽƌƚĂŐĞƐŽĨǁĂƚĞƌŝŶƌĞƐĞƌǀŽŝƌƐ͕ƐƚƌĞĂŵƐ͕ĂŶĚ ǁĞůůƐ
x tĂƚĞƌĞŵĞƌŐĞŶĐŝĞƐĂŶĚƉŽƐƐŝďůĞŵĂŶĚĂƚŽƌLJƌĂƟŽŶŝŶŐx ^ĞǀĞƌĞŝŵƉĂĐƚƐŽŶĞĐŽƐLJƐƚĞŵƐĂŶĚǁŝůĚůŝĨĞŚĂďŝƚĂƚƐ D3 EXTREME
DROUGHT
x DĂũŽƌĂŐƌŝĐƵůƚƵƌĂůůŽƐƐĞƐĂŶĚƉĂƐƚƵƌĞĨĂŝůƵƌĞx tŝĚĞƐƉƌĞĂĚǁĂƚĞƌƐŚŽƌƚĂŐĞƐx tĂƚĞƌƵƐĞƌĞƐƚƌŝĐƟŽŶƐůŝŬĞůLJĞŶĨŽƌĐĞĚx /ŶĐƌĞĂƐĞĚƌŝƐŬŽĨǁŝůĚĮƌĞƐĂŶĚŚĞĂƚ-ƌĞůĂƚĞĚƐƚƌĞƐƐ D2 SEVERE
DROUGHT
x ƌŽƉĂŶĚƉĂƐƚƵƌĞůŽƐƐĞƐďĞĐŽŵŝŶŐůŝŬĞůLJx tĂƚĞƌƐŚŽƌƚĂŐĞƐďĞĐŽŵŝŶŐĐŽŵŵŽŶx >ŽĐĂůŐŽǀĞƌŶŵĞŶƚƐŵĂLJŝŵƉůĞŵĞŶƚǁĂƚĞƌƌĞƐƚƌŝĐƟŽŶƐx ,LJĚƌŽƉŽǁĞƌŐĞŶĞƌĂƟŽŶĂŶĚŝƌƌŝŐĂƟŽŶƉŽƚĞŶƟĂůůLJ ŝŵƉĂĐƚĞĚ
D1 MODERATE
DROUGHT
x EŽƟĐĞĂďůĞĚĂŵĂŐĞƚŽĐƌŽƉƐĂŶĚƉĂƐƚƵƌĞƐ
x tĂƚĞƌůĞǀĞůƐŝŶƐƚƌĞĂŵƐĂŶĚƌĞƐĞƌǀŽŝƌƐďĞŐŝŶƚŽĚĞĐůŝŶĞx sŽůƵŶƚĂƌLJǁĂƚĞƌ-ƵƐĞƌĞƐƚƌŝĐƟŽŶƐŵĂLJďĞƌĞƋƵĞƐƚĞĚx ^ŽŵĞƐƚƌĞƐƐŽŶĮƐŚĂŶĚǁŝůĚůŝĨĞƉŽƉƵůĂƟŽŶƐ D0 ABNORMALLY
DRY
x
ĂƌůLJƐŝŐŶƐŽĨĚƌŽƵŐŚƚ͕ǁŝƚŚƐŚŽƌƚ-ƚĞƌŵĚƌLJŶĞƐƐƐůŽǁŝŶŐ ƉůĂŶƟŶŐĂŶĚĐƌŽƉŐƌŽǁƚŚ
x /ĨŝŵƉƌŽǀŝŶŐůŝŶŐĞƌŝŶŐǁĂƚĞƌĚĞĮĐŝƚƐĂƐĂƌĞĂƌĞĐŽǀĞƌƐ ĨƌŽŵĚƌŽƵŐŚƚ
x WĂƐƚƵƌĞƐŽƌǀĞŐĞƚĂƟŽŶŵĂLJƐŚŽǁƐŝŐŶƐŽĨĚĞůĂLJĞĚ
ƌĞĐŽǀĞƌLJ
Figure 6.5.1 Drought Categories and Associated Impacts
3UNmN J]AmmVœJApVa_m _ap a_]y help guide resources and planning but also raise awareness about the broader consequences of prolonged dryness. Understanding the extent and severity of drought helps ensure timely response and mitigation efforts at ]aJA]mpApNA_LSNLNlA]]NvN]m County of Los AngelesAll-Hazards Mitigation Plan
6.5.4 History!am_TN]Nmaq_pyUAmNxiNlVN_JNL^q]pVi]NmVT_VœJA_pLlaqTUpmwVpUma^N]AmpV_Tseveral years. There have been no federal declarations or state proclamations for LlaqTUpV_pUN]AmpœvNyNAlm Figure 6.5.2, U.S. Drought Monitor, 2025
County of Los Angeles
All-Hazards Mitigation Plan
Notable historical drought periods include:
1. 1917-1921 – A widespread drought affecting most of California.2. 1976-1977 – One of the driest two-year periods in recorded history.3. 1987-1992 – A six-year drought that severely impacted water supplies and agriculture.
4. 2007-2009 – A prolonged drought leading to state-imposed water restrictions.5. 2011-2017 – 3UN ^amp mNvNlN LlaqTUp V_ ^aLNl_ UVmpaly lNmq]pV_T V_ groundwater depletion and mandatory conservation measures.
6. 2020-2022 – A]VSal_VA NxiNlVN_JNL A mVT_VœJA_p LlaqTUp wVpU !am _TN]Nm aq_pyNxiNlVN_JV_T´AI_al^A]]yLly´Ja_LVpVa_m
7. 2024-2025 – Los Angeles County is continuing to experience abnormally dry Ja_LVpVa_mwVpU]awNlAverage rainfalls and arid conditions. 3UN JUAlp AIavN pUNPalmer Drought Severity Index shows how drought conditions have been changing since 1895. The Palmer Drought Severity Index measures how dry or wet an area is by comparing rainfall and temperature to long-term averages. It gives a number (positive or negative) showing drought severity or excess moisture. Los Angeles County was in some form of drought for 376 consecutive weeks from NJN^INlq_pV]"AlJU The State and the County passed several resolutions and regulations at different times to mitigate drought impacts like water Figure 6͘ϱ͘ϯ͕EKƌŽƵŐŚƚ^ĞǀĞƌŝƚLJ/ŶĚĞdž͕ϮϬϮϰ
County of Los AngelesAll-Hazards Mitigation Plan
conservation regulations. There were no federally declared drought disasters in the AlNAV_pUNiAmpœvNyNAlmV_pUNi]A__V_TAlNA6.5.5 Probability Climate scientists predict that Los Angeles County and the rest of Southern California wV]]TNpLlVNlwUV]NNorthern California will get hotter. Rising temperatures contribute pa UVTUNl NvAialApVa_ lApNm A_L LNJ]V_V_T m_awiAJ\ V_ pUN 1VNllA #NvALA A JlVpVJA]source of water for Southern California. The frequency of extreme droughts is expected paV_JlNAmNlNLqJing available water resources and heightening competition between qlIA_ ATlVJq]pqlA] A_L N_vVla_^N_pA] _NNLm Long-term droughts have a 100% of occurring every ten-years wVpU iapN_pVA] Sal ]a_TNl A_L ^alN LNmplqJpVvN LlaqTUpevents due to climate change.6.5.6 Vulnerability Los Angeles County’s 10 million residents face growing vulnerabilities during ila]a_TNLLlaqTUpmwVpUavNl ÈaSJa^^q_VpywApNlmympN^mNxUVIVpV_TAp]NAmpa_Ndrought-lN]ApNL lVm\mqJUAm lN]VA_JNa_ AmV_T]NmaqlJNalATV_TV_SlAmplqJpqlN3UNCounty’s dependence on imported water—serving over 60% of residents—increases exposure to supply disruptions from reduced Sierra Nevada snowpack and Colorado River allocations. ]]lNmVLN_pmA_LvVmVpalmaS Los Angeles County are affected by water shortages during a prolonged drought conditions.Vulnerabilities include:
x Low-income householdsaSpN_]AJ\V_TwApNl-NSœJVN_pAii]VA_JNmA_LJaa]V_T systems.
x Agricultural industry wVpU avNl AJlNm aS VllVTApNL SAl^]A_L V_ pUN County is at risk of reduced water allocation and drying pastures for livestock. x Wildland-urban interface (WUI) communitieswUNlNavNl^V]]Va_lNmVLN_pm SAJNUNVTUpN_NLwV]LœlNlVm\LqNpaLlyvNTNpApVa_A_L]V^VpNLœlNœTUpV_TwApNlsupply. x Critical infrastructure operations may be impacted by a range of factors from reduced hydropower availability when reservoir levels decrease to power station cooling challenges.
County of Los Angeles
All-Hazards Mitigation Plan
These vulnerabilities illustrate the far-lNAJUV_TJlamm-sector impacts of drought on the aq_py¯mNJa_a^yN_vVla_^N_pA_L^ampAp-risk communities. 6.5.7 Impacts %vNl pUN iAmp œvN yNAlm !am_TN]Nm aq_py UAm NxiNlVN_JNL V_pN_mVSyV_T LlaqTUpJa_LVpVa_m^Al\NLIy lVmV_T pN^iNlApqlNm lNLqJNL m_awiAJ\ A_L persistent water mUalpATNm y
ÈaSpUNaq_py¯mJa^^q_VpywApNlmympN^mmUawNLAp]NAmpa_NLlaqTUp vq]_NlAIV]Vpy V_J]qLV_T lN]VA_JN a_ A mV_T]N wApNl maqlJN al ATV_TV_SlAmplqJpqlN-qI]VJUNA]pUV^iAJpmUAvNA]maN^NlTNLwVpUJAmNmaS9Alley fever lNialpNLV_]V_\NLpaLlymaV]A_LLqmpNxiamqlNyLlaiawNllNLqJpVa_mLqlV_TLlaqTUp iNlVaLm V_JlNAmNL lN]VA_JN a_ _ApqlA] TAm Ja_plVIqpV_T pa N]NvApNL N_NlTyJampmSal lNmVLN_pm3UNmN Ja^iaq_LV_T V^iAJpm UAvN mplAV_NL wApNl mqii]y UNalth mympN^mA_LV_SlAmplqJpqlNlNV_SalJV_TLlaqTUpAmA^A[alA_LTlawV_TUA|AlLSal!amAngeles County.6.5.8 Mitigation and Preparedness 3a Ja^IAp V_JlNAmV_T LlaqTUp lVm\m !am _TN]Nm aq_py UAm V^i]N^N_pNL wApNlJa_mNlvApVa_ia]VJVNmV_SlAmplqJpqlNV_vNmp^N_pmA_LN^NlTN_JylNmia_mN^NAmqlNm Key strategies include: Water Management and Conservation x Expanding water recycling and desalination programs to reduce reliance on imported water.
x Implementing drought-tolerant landscaping initiatives to lower residential and commercial water use.
x _SalJV_TwApNlNSœJVN_JylNTq]ApVa_mSal_NwLNvN]ai^N_pmA_Lupgrading older properties with water-saving strategies.
Infrastructure Improvements x Enhancing groundwater recharge projects to increase local water storage. x Upgrading stormwater capture systems to maximize water retention during rainy seasons.
x Developing new water storage facilities to provide additional supply resilience. Community Preparedness and Public Awareness County of Los Angeles All-Hazards Mitigation Plan
x Launching county-wide conservation campaigns to encourage sustainable water use.
x _JlNAmV_Tœ_A_JVA]V_JN_pVvNmSalwApNl-NSœJVN_pAii]VA_JNmA_LVllVTApVa_mympN^mx Strengthening emergency drought response plans to ensure equitable water distribution during crises.
6.5.9 Summary Drought remains a persistent and growing threat to Los Angeles County’s water security and economic stability. Climate change projections indicate more frequent A_LmNvNlNLlaqTUpmi]AJV_TTlNApNlmplAV_a_wApNlmqii]ymympN^miqI]VJUNA]pUA_Lagriculture. By implementing proactive water management mplApNTVNm V_vNmpV_T V_V_SlAmplqJpqlN lNmV]VN_JN A_L ila^apV_T Ja^^q_Vpy AwAlN_Nmm pUN aq_py JA_mitigate the long-term impacts of drought and ensure sustainable water resources for future generations.
County of Los Angeles
All-Hazards Mitigation Plan
County of LosA ngelesAll-Hazards Mitigation Plan6.6 Flooding6.6.1 Nature Flooding is a persistent and increasingly severe UA|AlL V_ !am _TN]Nm aq_py LlVvN_ Iy UNAvylAV_SA]]mpal^mqlTNmpal^wApNlLlAV_ATNA_LlVmV_TmNA ]NvN]m 3UN Jaq_py¯m Ja^i]Nx UyLla]aTy wUVJUV_J]qLNmlVvNlmJlNN\mA_LA_NxpN_mVvNqlIA_ŔaaLco_pla] mympN^ Vm UVTU]y mqmJNipVI]N pa avNlŔawevents when precipitation exceeds drainage capacity. 3UNNSSNJpmaSJ]V^ApNJUA_TNAlNNxAJNlIApV_TŔaaLlVm\m Iy V_pN_mVSyV_T mpal^m A]pNlV_T ilNJViVpApVa_iAppNl_mA_LV_JlNAmV_TmNA]NvN]m]NALV_TpaTreater JaAmpA]V_q_LApVa_A_LV_]A_LŔAmUŔaaLmUnlike other regions that experience seasonal ŔaaLV_T LqN pa m_aw^N]p ŔaaLV_T V_ !am _TN]NmCounty primarily occurs during winter storms and Ap^amiUNlVJlVvNlNvN_pmwUVJUIlV_TV_pN_mNlAV_SA]]and lightning over short periods.x 3UN lNTVa_¯m UVTULNTlNNaS qlIA_V|ApVa_ Ja_plVIqpNm pa ŔAmU ŔaaLV_T Am iAvNL mqlSAJNm ilNvN_p _ApqlA] AImalipVa_ aS wApNl ]NALV_T pa lAiVLlq_aSS A_L mplNNpŔaaLV_T County of Los AngelesAll-Hazards Mitigation Plan
x
ql_ mJAlm Sla^ lNJN_p wV]LœlNm SqlpUNl Ja^iaq_L ŔaaL lVm\m Iy lNLqJV_T vNTNpApVa_ JavNl LNmpAIV]V|V_T UV]]mVLNm A_L V_JlNAmV_T pUN ]V\N]VUaaL aS ]A_Lmovement. ]aaLV_T A]ma JlNApNm mNJa_LAly UA|AlLm V_J]qLV_T NlamVa_ V_SlAmplqJpqlN LA^ATNwApNlJa_pA^V_ApVa_A_LplA_mialpApVa_LVmlqipVa_m1pal^wApNllq_aSSJA_avNlwUN]^wAmpNwApNlplNAp^N_pSAJV]VpVNm]NALV_TpaUA|AlLaqmmiV]]m!A_Lm]VLNmA_L^qLŔawmin post-wV]LœlNAlNAmiamNALLVpVa_A]lVm\mpaUa^NmlaALmA_LJlVpVJA]V_SlAmplqJpqlN3UNmN Ja^iaq_LV_T pUlNApm UVTU]VTUp pUN qlTN_p _NNL Sal Ja^ilNUN_mVvN ŔaaL^VpVTApVa_NSSalpmpailapNJpJa^^q_VpVNmV_SlAmplqJpqlNA_LpUNN_vVla_^N_p6.6.2 Location ]aaLUA|AlLmAlNTNaTlAiUVJA]]ywVLNmilNALwVpU^alNpUA_mkqAlN^V]NmaS]A_Llocated within the 100- and 500-yNAlŔaaLi]AV_mVmpalVJA]]ymVT_VœJA_pNvN_pmmqJUAmpUNA_LŔaaLmAmwN]]Am^alNlNJN_pmpal^mV_A_LUAvNJAqmNLmqImpA_pVA]LA^ATNpaV_SlAmplqJpqlNplVTTNlNLNvAJqApVa_mA_LJUA]]N_TNL]a_T-term recovery efforts. SocVA]]y vq]_NlAI]N iaiq]ApVa_m V_J]qLV_T a]LNl ALq]pm V_LVvVLqA]mwVpUAJJNmmA_LSq_JpVa_A]_NNLmA_L]aw-V_Ja^NUaqmNUa]LmSAJNLVmilaialpVa_ApNV^iAJpm LqN pa ]V^VpNL œ_A_JVA] lNmaqlJNm V_ALNkqApN V_mqlA_JN JavNlATN A_Lreduced access to services. 3UNaq_py¯mŔaaLJa_pla]mympN^V_J]qLNmJa_JlNpNlVvNlJUA__N]m]NvNNmmpal^LlAV_mLNIlVmIAmV_mA_LlNmNlvaVlmUAmUN]iNL^VpVTApNma^NŔaaL lVm\m Iqp lN^AV_m vq]_NlAI]N pa UVTU-intensity storms that exceed design capacities.Major Flood-Prone Areas:x !am_TN]Nm0VvNl1A_AIlVN]0VvNlA_L1A_pA]AlA0VvNl3UNmN^A[alwApNlwAym AlN ila_N pa avNlŔaw LqlV_T NxplN^N mpal^ NvN_pm iAlpVJq]Al]y LqlV_T ] #V`ayears. x Ballona Creek and Malibu Creek: These urban watersheds experience rapid runoff A_LŔAmUŔaaLV_TNmiNJVA]]yV_LNvN]aiNLAlNAm
x aapUV]]m9A]]NymA_L0NJN_p
ql_1JAllNAm-amp-wV]LœlNlNTVa_mSAJNUNVTUpN_NL
lVm\aSŔAmUŔaaLmA_LLNIlVmŔawmSa]]awV_Tmpal^m
x _pN]aiN9A]]Ny_LNmNlplNTVa_mmpal^wApNliaa]mV_papN^ialAly]A\NmJAqmV_T ŔaaLNLlaALwAymA_LV_SlAmplqJpqlNLA^ATN
County of Los Angeles
All-Hazards Mitigation Plan
x Coastal Communities: Rising sea levels and storm surges threaten beachfront ilaiNlpVNmUAlIalmA_LIqmV_NmmNm
Urban areas are particularly vulnerable due to impervious surfaces and outdated LlAV_ATNmympN^mqlV_TV_pN_mNmpal^m_NVTUIalUaaLmV_aw_paw_!am_TN]Nm 1aqpU!A_LpUN1A_Nl_A_La9A]]NySlNkqN_p]yNxiNlVN_JNmplNNpŔaaLV_TA_LplASœJdisruptia_mLN^a_mplApV_TpUN]V^VpApVa_maSNxVmpV_TV_SlAmplqJpqlNV_UA_L]V_T^aLNl_storm events. For a better visual representation of this Flooding Hazard within the LA County i]A__V_TAlNAi]NAmNlNSNlN_JNiiN_LVx for ŔaaLA_LV_q_LApVa_^Aim.
6.6.3 Extent !am_TN]Nmaq_pySAJNmAmVT_VœJA_pA_LNva]vV_TŔaaL lVm\wVpUV^iAJpmlA_TV_TSla^]aJA]V|NLqlIA_V_q_LApVa_pawVLNmilNALlVvNlV_NŔaaLV_TA_LLNmplqJpVvNLNIlVmŔawm ]pUaqTU pUN aq_py UAm V_vNmpNL UNAvV]y V_ ŔaaL Ja_pla] V_SlAmplqJpqlNinc]qLV_T A_ NxpN_mVvN _Npwal\ aS LA^m A_L LNIlVm IAmV_m pUNmN mympN^m AlN increasingly strained and cannot fully eliminate the threat. A growing number of lNmVLN_pmAlNNxiamNLpaLA_TNlaqmŔaaLV_TNAJUyNAlAmVpqApVa_^ALNwalmNIypUNlimitations of aging infrastructure and the complexities of urban hydrology. Intense lAV_SA]]NvN_pmNmiNJVA]]ypUamNAmmaJVApNLwVpUAp^amiUNlVJlVvNlmAlNaJJqllV_T^alNSlNkqN_p]y A_L wVpU TlNApNl mNvNlVpy aSpN_ avNlwUN]^V_T LlAV_ATN mympN^m A_LlNmq]pV_TV_mNvNlNŔooding of streets and neighborhoods. Compounding this risk are Iql_mJAlmSla^lNJN_pwV]LœlNmwUVJUUNVTUpN_pUN]V\N]VUaaLaS^qLm]VLNmA_LLNIlVmŔawmpUAppUlNApN_IapU]VSNA_LilaiNlpymJ]V^ApNiAppNl_mmUVSpA_LNxplN^NwNApUNlevents become ^alNJa^^a_pUNŔaaLvq]_NlAIV]VpyaS!am_TN]Nmaq_pyJa_pV_qNmto deepen across its diverse geography.
Flood severity is typically measured using the 100-year and 500-yNAlŔaaLlNJqllN_JNV_pNlvA]mwUVJUV_LVJApN A È A_L È A__qA]ilaIAIV]VpyaS ŔaaLV_T lNmiNJpVvN]y3UNmNLNmVT_ApVa_mTqVLNŔaaLi]AV_^A_ATN^N_pA_L^VpVTApVa_NSSalpmKey Flood Hazard Statistics in Los Angeles County: x mkqAlN^V]Nm È aS]A_LUAvNAÈA__qA]ŔaaLilaIAIV]Vpyx mkqAlN^V]NmÈ UAvNAÈA__qA]ŔaaLilaIAIV]Vpy County of Los Angeles All-Hazards Mitigation Plan
Key Flood Hazard Statistics for Unincorporated Los Angeles County: x mkqAlN^V]NmÈ UAvNAÈŔaaLilaIAIV]Vpyx mkqAlN^V]NmÈ UAvNAÈŔaaLilaIAIV]VpyAs climate change accelerates sea-]NvN]lVmNA_LNxplN^NlAV_SA]]NvN_pmpUNmNŔaaLila_NAlNAm^AyNxiA_LASSNJpV_T^alNlNmVLN_pmV_SlAmplqJpqlNA_LIqmV_NmmNm !%%"-3%#!#0
Area 0.2% Annual Flood Probability 1% Annual Flood Probability Los Angeles County 243.32 sq. mi. (5.11%) 4.19 sq. mi. (0.09%) Unincorporated LA County 64.77 sq. mi. (2.13%) 1.23 sq. mi. (0.04%)
6.6.4 History !am_TN]Nmaq_pyUAmNxiNlVN_JNL_q^NlaqmmNvNlN ŔaaLNvN_pm^A_yaSwUVJUUAvNJAqmNLJApAmplaiUVJLA^ATNpaV_SlAmplqJpqlNilaiNlpyA_LUq^A_]VSN%vNlpUNLNJALNmJ]V^ApNvAlVAIV]VpylAiVLqlIA_V|ApVa_A_LA_ATV_TŔaaLJa_pla]mympN^UAvNleL palNiNApNLŔaaLV_TLVmAmpNlmThere have been no federal declarations or state ilaJ]A^ApVa_mSalNAlpUkqA\NmV_pUN]AmpœvNyNAlm N]awAlNma^NaSpUN^ampmVT_VœJA_pUVmpalVJA]A_LlNJN_pŔaaLNvN_pmASSNJpV_TpUNregion. Notable Flood and Lightning Events in Los Angeles County: x 1938 Los Angeles Floods%_NaSpUNLNAL]VNmpŔaaLmV_Jaq_pyUVmpalyJAqmNLIy wNN\m aS pallN_pVA] lAV_SA]] lNmq]pV_T V_ avNl LNApUm pUN LNmplqJpVa_ aSpUaqmA_LmaSUa^NmA_LwVLNmilNALV_SlAmplqJpqlNLA^ATNiAlpVJq]Al]ypaIlVLTNmand roadways. x 1969 Winter StormsNAvylAV_m]NL pa^AmmVvNLNIlVmŔawmV_ pUN1A_AIlVN] "aq_pAV_mmNvNlNqlIA_ŔaaLV_TAJlamm!am_TN]NmA_L^q]pVi]NLA^IlNAJUNmprompting major evacuations. x 1992-1993 El Niño FloodsmNlVNmaSmpal^mplVTTNlNL]A_Lm]VLNmŔAmUŔaaLV_T A_L^A[al JaAmpA]NlamVa_wVpUmVT_VœJA_pLA^ATN pa-AJVœJaAmpVTUwAyA_Lresidential areas. x :V_pNl1pal^m0-4305): Record-IlNA\V_TlAV_SA]]]NLpamVT_VœJA_pqlIA_ ŔaaLV_T laAL J]amqlNm A_L ^qLm]VLNm wVpU mNvNlN V^iAJpm AJlamm ^q]pVi]N communities.
County of Los Angeles
All-Hazards Mitigation Plan
x October 2021: Los Angeles County experienced a rare and intense thunderstorm wVpUAmVT_VœJA_pA^aq_paS]VTUp_V_T
x September 2022 Hurricane KayiAJVœJUqllVJA_NpUApJAqmNLmVT_VœJA_plAV_SA]] A]a_TwVpUlVm\aS^qLŔawmJaAmpA]ŔaaLV_TA_LJaAmpA]NlamVa_ x A_qAlyp^amiUNlVJ0VvNlvN_p0-4683): Heavy rainfall overwhelmed mpal^LlAV_mJAqmV_TmVT_VœJA_pŔaaLV_TV_a]]ywaaL A]LwV_V]]mA_L]aw-lying V_]A_LAlNAm]NALV_TpaNvAJqApVa_mA_LV_SlAmplqJpqlNLA^ATN x NIlqAly!am_TN]Nm]aaLm0-4699): A series of intense storms caused wVLNmilNAL ŔAmU ŔaaLV_T SlNNwAy J]amqlNm A_L ]A_Lm]VLNm LN^a_mplApV_T pUN increasing vulnerability of the county's urban areas to extreme precipitation events. x qTqmp3laiVJA]1pal^V]Aly0-4750): Several locations in the mountains of Southern California received over 10 inches of rainfall which set daily and/or ^a_pU]ylAV_SA]]lNJalLmV_^A_y]aJApVa_mV_1aqpUNl_A]VSal_VAV_J]qLV_TwVpUV_!am_TN]Nmaq_pypA]maJlNApNLmVT_VœJA_ppUlNApaSŔAmUA_LlVvNlV_NŔaaLV_Tprompted the evacuation of numerous vulnerable communities near burn scars in the region. x NJN^INl-AJVœJ1pal^1pal^mqlTNmA_LNxplN^NJaAmpA]ŔaaLV_T]NLpa mVT_VœJA_pNlamVa_A]a_TpUNJaAmp]V_NiAlpVJq]Al]yV^iAJpV_T"AlV_ALN]0Ny!a_T NAJUA_L9N_VJN
NAJU
x February - "AlJUp^amiUNlVJ0VvNl1pal^0-4769): One of the most V_pN_mNlAV_SA]]NvN_pmV_lNJN_pUVmpalylNmq]pV_TV_mNvNlNŔAmUŔaaLm^qLm]VLNmA_LiawNlaqpATNmwVpU^A_yUa^NmA_LIqmV_NmmNmmqmpAV_V_TŔaaLLA^ATN
6.6.5 Probability ]aaLlNJqllN_JNV_!am_TN]Nmaq_pyVmV_ŔqN_JNLIyIapU_ApqlA]J]V^ApNvAlVAIV]VpyA_LpUNV_JlNAmV_TNSSNJpmaSJ]V^ApNJUA_TNVmpalVJA]]ymNvNlNŔaaLV_TVm^amp]V\N]yLqlV_Tmpla_T]#V`aNvN_pmwUVJUaJJqlAiilaxV^ApN]yNvNly payNAlmAnd can persist for several months to multiple years. These events bring elevated precipitation ]NvN]mA_LV_JlNAmNpUN]V\N]VUaaLaSIapUV_]A_LA_LJaAmpA]ŔaaLV_TmJ]V^ApNJUA_TNAJJN]NlApNmpUNSlNkqN_JyA_LV_pN_mVpyaSŔaaL-generating events AlNNxiNJpNL paV_JlNAmNA]pNlV_T plALVpVa_A] lNJqllN_JNV_pNlvA]mA_LNxiA_LV_T pUNareas at risk. 3UNlNVmA ÈJUA_JNaSAŔaaLV_TNvN_paJJqllV_TNAJUyNAlwVpUV_T!amAngeles County.
County of Los Angeles All-Hazards Mitigation Plan
Key climate-related drivers include: x Sea-!NvN]0VmN-la[NJpNLpalVmNIyV_JUNmpaavNlSNNpIy V_JlNAmV_TpUN
lVm\aSpVLA]A_Lmpal^mqlTNŔaaLV_TV_JaAmpA]Ja^^q_VpVNm x p^amiUNlVJ 0VvNl vN_pm JJalLV_T pa pUN 30 pUNmN NvN_pm AlN INJa^V_T^alNSlNkqN_pA_LV_pN_mN]NALV_T paN]NvApNLŔAmUŔaaLA_LLNIlVmŔawlVm\m x El Niño Cycles1pV]]NxiNJpNLNvNlypayNAlmIqpwVpUV_JlNAmNLvAlVAIV]VpyA_L mpal^V_pN_mVpypUApJA_avNlwUN]^]aJA]LlAV_ATNA_LŔaaLJa_pla]mympN^m. 3UNmN Nva]vV_T Ja_LVpVa_m JUA]]N_TN NxVmpV_T ŔaaLi]AV_ ^Aim A_L LNmVT_Ammq^ipVa_mUVTU]VTUpV_T pUN_NNLSalALAipVvNi]A__V_TqiLApNLlVm\^aLN]mA_LJa_pV_qNLV_vNmp^N_pV_lNmV]VN_pV_SlAmplqJpqlNA_LŔaaL^VpVTApVa_mplApNTVNm
6.6.6 Vulnerability !am_TN]Nmaq_pySAJNmwVLNmilNALA_L]AyNlNLvq]_NlAIV]VpVNmpaŔaaLV_TmUAiNLby a combination of environmental exposure and complex social factors. Physical vulnerability is pronounced in areas located within FEMA-designated Special Flood A|AlLlNAm 1m iamp-wV]LœlNIql_mJAlmA_L]aw-lying urban drainage basins pUApAlNila_NpaŔaaLV_TawNvNlpUNLNTlNNaSlVm\VmmVT_VœJA_p]yUNVTUpN_NLSalJNlpAV_iaiq]ApVa_mwUa^Ay]AJ\pUNlNmaqlJNmalJAiAJVpypailNiAlNSallNmia_Lpaand reJavNl Sla^ ŔaaL NvN_pm 1aJVA]]y vq]_NlAI]N Tlaqim V_J]qLV_T a]LNl ALq]pmV_LVvVLqA]m wVpU LVmAIV]VpVNm al AJJNmm A_L Sq_JpVa_A] _NNLm # ^aIV]N Ua^NlNmVLN_pmiNai]NNxiNlVN_JV_TUa^N]Nmm_NmmA_L]aw-V_Ja^NUaqmNUa]LmAlN^alNlikely to reside in structurally vulnerable housing. According to the 2021 Los Angeles County Comprehensive Floodplain Management -]A_^alN pUA_AkqAlpNlaS lNmVLN_pm]VvV_TwVpUV_ pUN-yNAlŔaaLi]AV_NAl_]NmmpUA_¸A__qA]]yq_LNlmJalV_TpUNLVmilaialpVa_ApNNJa_a^VJIqlLN_SAJNLIythose least able to absorb the costs of recovery. Climate vulnerability data further LN^a_mplApNm pUAp ^AlTV_A]V|NL Ja^^q_VpVNm V_ ŔaaL-exposed areas face elevated lVm\mLqN pa ŔaaLV_TNvN_pm3UNvq]_NlAIV]Vpy]A_LmJAiNVmSqlpUNl Ja^i]VJApNLIyAshortage of affalLAI]NŔaaL-lNmV]VN_pmplqJpqlNmA_LA_V_JlNAmV_T_q^INlaSlNmVLN_pmliving in areas newly exposed due to climate-driven changes in precipitation and runoff patterns.
County of Los Angeles
All-Hazards Mitigation Plan
6.6.7 Impacts Flooding in Los Angeles County leads to a broad range of direct and cascading impacts a_ iNai]N V_SlAmplqJpqlN N_vVla_^N_p A_L pUN NJa_a^y 3UN aq_py¯m NxpN_mVvN_Npwal\ aS JlVpVJA] SAJV]VpVNm V_J]qLV_T UamiVpA]m œlN mpApVa_m wAmpNwApNl plNAp^N_pp]A_pm mJUaa]m A_L iawNl mqImpApVa_m 3UNmN AlNAmSAJN lNJqllV_T NxiamqlN wVpUV_both 100- and 500-yNAlŔaaLi]AV_mA^ATNpapUNmNSAJV]VpVNm_apa_]yJa^ila^VmNmtheir physical integrity but also threatens their functionality during emergency response operations. ]aaLV_TaSpN_LVmlqipm]VSN]V_NmNlvVJNm mqJU AmN]NJplVJVpyiapAI]NwApNlmA_VpApVa_A_LplA_mialpApVa_wVpUlqlA]A_Lq_V_JalialApNLAlNAmSAJV_TpUNTlNApNmpJUA]]N_TNmpa lAiVL lNmpalApVa_ "aIV]N Ua^Nm SlNkqN_p]y Ja_JN_plApNL V_ ]aw-lying or underLlAV_NL _NVTUIalUaaLm AlN NmiNJVA]]y mqmJNipVI]N pa ŔaaL LA^ATN LqN paJa_mplqJpVa_ ]V^VpApVa_m A_L V_ALNkqApN ilapNJpVvN ^NAmqlNm -lNvVaqm ŔaaL NvN_pmUAvNlNmq]pNLV_mVT_VœJA_pLNIlVmŔawmlaALJ]amqlNmplAV_mpaiiATNmA_LLA^ATNto public and private structures. -lV^Aly9q]_NlAIV]VpVNmË^iAJpmx %vNlmplqJpqlNmAlNNmpV^ApNLpaINLA^ATNLV_A-yNAlŔaaLNvN_pwVpU papA]LA^ATNmNxJNNLV_T¸^V]]Va_V_ilaiNlpy]ammNmV_q_V_JalialApNL!amAngeles County. x LLVpVa_A]]y^alNpUA_JlVpVJA]SAJV]VpVNmAlNNxiamNLV_pUN -yNAlŔaaLi]AV_
while 70 are within the 100-yNAlŔaaLi]AV_V_J]qLV_TplA_mialpApVa_AmmNpmqpV]VpVNmN^NlTN_JymNlvVJNmA_LUA|AlLaqm^ApNlVA]mSAJV]VpVNm x A 100-yNAlŔaaLNvN_pJaq]LLVmi]AJNavNlApUaqmA_LiNai]NwVpU^A_ylNkqVlV_T mUN]pNlV_TmqiialpA_LlNJavNlyNSSalpm
x iilaxV^ApN]y
pa_maSIqV]LV_T-related debris could be generated by a 100- yNAl ŔaaL NvN_p wVpU J]NA_-qi lNkqVlV_T ^alN pUA_ plqJ\]aALm iamV_T]aTVmpVJA]N_vVla_^N_pA]A_LiqI]VJUNA]pUJUA]]N_TNm x 28.6% of households in the 100-yNAlŔaaLi]AV_AlNNJa_a^VJA]]yLVmALvA_pATNL NAl_V_Tq_LNl¸iNlyNAl]V^VpV_TpUNVlAIV]VpypaNvAJqApNlNJavNlaliAySalmitigation improvements. x ]AlTNmUAlNaSŔaaL-prone properties are either uninsured or underinsured. The AvNlATNŔaaLV_mqlA_JNJ]AV^iAyaqpVm¸wUVJUVma_]yAIaqpÈaSpUN County of Los Angeles All-Hazards Mitigation Plan
ŚĂƌƚƐ^ŽƵƌĐĞ͗ >ŽƵŶƚLJWƵďůŝĐtŽƌŬƐ͖ϮϬϮϭ ŽƵŶƚLJŽŵƉƌĞŚĞŶƐŝǀĞ&ůŽŽĚWůĂŶ AvNlATNlNi]AJN^N_pJampaSmplqJpqlNmV_pUNŔaaLi]AV_—V_LVJApV_TmVT_VœJA_pTAimV_œ_A_JVA]lNmV]VN_JN x :V]LœlNIql_mJAlmA_Liamp-œlNUyLlaiUaIVJmaV]mmVT_VœJA_p]yV_JlNAmNŔaaLA_L LNIlVm Ŕaw lVm\m iAlpVJq]Al]y V_ SaapUV]] A_L JA_ya_ Ja^^q_VpVNm 3UVm UA|AlLcontinues to grow in severity with climate-LlVvN_œlNmNAma_m
6.6.8 Mitigation and Preparedness !am _TN]Nm aq_py¯m ŔaaL ^VpVTApVa_ mplApNTy lNLqJNm UA|AlL NxiamqlN N_UA_JNmJa^^q_VpylNmV]VN_JNA_Lmqiialpm]a_T-term climate adaptation. Grounded in FEMA’s #ApVa_A] "VpVTApVa_ lA^Nwal\ A]%1 i]A__V_T TqVLA_JN A_L ]aJA] ia]VJy pUN County implements both structural and non-structural measures to address current and SqpqlNŔaaLlVm\malNAJpVa_mV_J]qLNlNTq]Al^AV_pN_A_JNA_LpAlTNpNLqiTlALNmpa Estimated Damage to Critical Facilities in Unincorporated Areas from 100-Year Flood Sector Number of Facilities Affected Average % of Total 9A]qN Damaged Structure Content Safety & Security 1 7.56 10.24
Food, Water & Sheltering 9 6.72 18.73
Health & Medical 0 N/A N/A
Energy 1 23.90 47.79
Communications 0 N/A N/A
Transportation 59 1.41 8.86
Hazardous Materials 0 N/A N/A
Total/Average 70 9.90 21.40
Estimated Damage to Critical Facilities in Unincorporated Areas from 500-Year Flood Sector Number of Facilities Affected
Average % of Total 9A]qN
Damaged
Structure Content
Safety & Security 4 28.39 37.56
Food, Water & Sheltering 41 7.73 27.01
Health & Medical 0 N/A N/A
Energy 1 23.90 47.79
Communications 2 5.00 16.00
Transportation 107 3.38 19.74
Hazardous Materials 30 10.00 15.00
Total/Average 185 13.07 27.18
County of Los Angeles
All-Hazards Mitigation Plan
mpal^wApNlV_SlAmplqJpqlN lNmpalApVa_aS ŔaaLi]AV_m A_LV_pNTlApVa_aS ŔaaL UA|AlLdata into land use planning. The County also prioritizes the protection of critical SAJV]VpVNm A_L vq]_NlAI]N UaqmV_T pUlaqTU mVpN lNplaœpm ilaiNlpy AJkqVmVpVa_ A_Le]NvApVa_ilaTlA^m-qI]VJaqplNAJUVmJa_LqJpNLpUlaqTUAIV]V_TqA]-accessible -laTlA^Sal -qI]VJ_Sal^ApVa_wUVJUila^apNm ŔaaL mASNpy AwAlN_Nmm N^NlTN_JyilNiAlNL_NmmA_LiAlpVJViApVa_V_pUN#ApVa_A]]aaL_mqlA_JN-laTlA^#- To ensure that mitigation is both data-driven and community-JN_pNlNL pUN aq_pyqpV]V|NmJ]V^ApNila[NJpVa_mA_L"¯m?41^aLN]V_TpaV_Sal^V_vNmp^N_pmwUV]Ncoordinating with regional partners to align local actions with broader watershed strategies. Key components of the approach include: x 4iTlALV_T Jq]vNlpm LNIlVm IAmV_m A_L LlAV_ATN mympN^m pa ^A_ATN V_JlNAmNL runoff
x Promoting low-impact development (LID) and incorporating green infrastructure in urban design
x Updating ordinances and the General Plan to discourage development in high-risk areas
x Maintaining inventories of repetitive loss areas and prioritizing resources for the most vulnerable populations
This comprehensive strategy ensures Los Angeles County not only meets federal and mpApN mpA_LAlLm Iqp ALvA_JNm ŔaaL lVm\ lNLqJpVa_ V_ A wAy pUAp mASNTqAlLm iNai]NilaiNlpyA_L_ApqlA]mympN^mSalpUNSqpqlN6.6.9 Summary Flooding is one of the most persistent and complex natural hazards in Los Angeles aq_pyV_pN_mVœNLIyJ]V^ApNJUA_TNqlIA_V|ApVa_A_LATV_TV_SlAmplqJpqlN3UN!am_TN]Nm aq_py lNTVa_ NxiNlVN_JNm A lA_TN aS ŔaaL pyiNm including stormwater lq_aSSŔAmUŔaaLV_TJaAmpA]V_q_LApVa_A_Liamp-wV]LœlNLNIlVmŔawm3UNmNNvN_pmare most common during winter storms and atmospheric river systems. High-density LNvN]ai^N_pNxpN_mVvNiAvNLmqlSAJNmA_LœlN-damaged hillsides contribute to rapid lq_aSSA_LV_JlNAmNLavNlA]]ŔaaLvq]_NlAIV]VpylNAmA]a_TIqp_ap]V^VpNLpa pUN!am_TN]Nm 1A_ AIlVN] A_L 1A_pA ]AlA 0VvNlm Am wN]] Am JaAmpA] Ja^^q_VpVNm A_LSaapUV]]lNTVa_mAlNiAlpVJq]Al]yAplVm\ County of Los Angeles All-Hazards Mitigation Plan
Los Angeles County’s mitigation strategy is proactive and multifaceted. It includes V_SlAmplqJpqlNqiTlALNm_ApqlN-IAmNLma]qpVa_m]A_LqmNia]VJyqiLApNmA_LiqI]VJNLqJApVa_alNilValVpVNmSaJqma_ilapNJpV_T JlVpVJA]SAJV]VpVNm lNLqJV_TNxiamqlNVn high-lVm\UaqmV_TA_Lila^apV_TJa^^q_VpylNmV]VN_JN-]A__V_TNSSalpmAlNmqiialpNLIy"¯m?41lVm\^aLN]V_TA_L]aJA]J]V^ApNila[NJpVa_mNmiVpNilaTlNmm^alNpUA_ lNmVLN_pmlN^AV_AplVm\Sla^^A[alŔaaLNvN_pmlNV_SalJV_TpUN_NNLfor Ja_pV_qNLV_vNmp^N_pV_Ja^ilNUN_mVvNŔaaLlVm\lNLqJpVa_AJlammpUNJaq_py6.6.10 National Flood Insurance Program (NFIP) Repetitive Loss (RL)
JJalLV_TpapUN!am_TN]Nmaq_py-qI]VJ:al\mpUNlNAlN
0NiNpVpVvN!amm0! properties in 28 RL areas of Unincorporated Los Angeles County as of 2025and 8 Severe Repetitive Loss Properties (SRLP). A Repetitive Loss (RL) property is any insurable IqV]LV_TSalwUVJUpwaal^alNJ]AV^maS^alNpUA_¸wNlNiAVLIypUN#ApVa_A]Flood Insurance Program (NFIP) in any rolling 10-year period since 1978. Updated location information about RL properties in Unincorporated Los Angeles County were not avai]AI]NLqlV_TpUNLlASpV_TaSpUVmi]A_IqpVmINV_Tœ_A]V|NLA_LwV]]INV_J]qLNLin subsequent hazard mitigation efforts. Data from 2011 showed that 24 RL properties were located in the SFHA. ppUNpV^NpUN!am_TN]Nmaq_py-qI]VJ:al\mmpApNL¬pUN^A[alVpy aS pUN lNiNpVpVvN ]ammNm AlN AmmaJVApNL wVpU ]aJA]V|NL qlIA_ LlAV_ATN ŔaaLilaI]N^mNvN_SalilaiNlpVNmwVpUV_A"-LNmVT_ApNLŔaaL|a_N3UN!am_TN]NmCounty Public Works oversees RL mitigation projects.
County of Los Angeles
All-Hazards Mitigation Plan
County of Los AngelesAll-HazardsMiti t gaion Plan6.7 Dam Failure6.7.1 Nature Dam failure refers to the structural collapse of a dam that results in the sudden and uncontrolled release of stored water. Such failures can occur due to age-lN]ApNL LNpNlValApVa_ V_ALNkqApNmiV]]wAy JAiAJVpy mplqJpqlA] LA^ATN Sla^mNVm^VJ AJpVvVpy al ŔaaLV_T A_L iaalmaintenance. The catastrophic release of water from a dam failure has the potential to cause human JAmqA]pVNmmVT_VœJA_pNJa_a^VJ]ammA_Lenvironmental destruction. This type of disaster is particularly dangerous because it can occur mqLLN_]y ]NAvV_T ]Vpp]N pV^N Sal NvAJqApVa_ alemergency response efforts.3UN ^AT_VpqLN aS ŔaaLV_T Sla^ LA^ SAV]qlNoften exceeds the capacity of downstream JUA__N]m JAqmV_T lAiVL V_q_LApVa_ aSmqllaq_LV_T AlNAm 3UVm ŔaaLV_T JA_ ]NAL paNxpN_mVvN ilaiNlpy LA^ATN NlamVa_V_SlAmplqJpqlNLNmplqJpVa_A_LJa_pA^V_ApVa_aSwatelmqii]VNmLLVpVa_A]]ymNJa_LAlyUA|AlLmmqJU Am ]A_Lm]VLNm A_L LNIlVm Ŕawm JA_ INplVTTNlNL Ja^iaq_LV_T pUN LVmAmpNl¯m V^iAJpThe structural stress on dams may rise as dams ATN A_L J]V^ApNvAlVAIV]VpyV_JlNAmNm pUNSlNkqN_JyaS NxplN^N ilNJViVpApVan events. Planning efforts include both dams and debris basins. To simplify language of the plan both reservoir dams and storm water debris basins will be referred to as dams.
County of Los AngelesAll-Hazards Mitigation Plan
6.7.2 LocationLos Angeles County has over 90 dams regulated by the California Department of Water Resources’ Division of Safety of Dams (DSOD). Fifteen (15) of these dams and eighteen (18) debris basins are owned and operated by the Los Angeles County Public Works -: _ pUN A]VSal_VA !NTVm]ApqlN ^A_LApNL pUAp A]] mpApN-jurisdictional dams NxJ]qLV_TpUamNJ]AmmVœNLAm!awA|AlL LNvN]aiLA^IlNAJUV_q_LApVa_^AimA_LEmergency Action Plans (EAPs) approved by DSOD and Cal OES."A_yaSpUNmNLA^mAlN]aJApNL_NAlUVTU]yiaiq]ApNLAlNAmV_JlNAmV_TpUNiapN_pVA]for human and economic impacts during a failure event. Seventy (70) dams are J]AmmVœNLAmVTUalxplN^N]yVTUUA|AlLiapN_pVA]LA^m^NA_V_TpUNVlSAV]qlNJaq]Lresult V_mVT_VœJA_p]ammaS]VSNA_LwVLNmilNALilaiNlpyLA^ATN3UN:UVppVNl#AllawmA^lNJ]AmmVœNLAmpUN41l^yalimaS_TV_NNlm¯41 highest-ilValVpyLA^mASNpyJa_JNl_iamNma_NaSpUNTlNApNmplVm\mLqNpaVpmiapN_pVA]pa ŔaaL UVTU]y iaiq]ApNL AlNAm Sla^ -VJa 0VvNlA pa !a_T NAJU 41 UAm
determined that an extreme storm event has a 1 in 900 (0.1%) chance of causing catastrophic failure annually. Mitigation actions related to County-owned dams are prioritized based on their hazard level and potential to impact populated areas. For a better visual representation of this Dam Failure Hazard within the LA County i]A__V_TAlNAplease reference Appendix A for all the County owned dams and debris basins maps.
6.7.3 Extent The Federal Guidelines for Inundation Mapping of Flood Risks Associated with Dam Incidents and Failures (FEMA P- JApNTalV|Nm LA^ UA|AlLm V_pa SaqlJ]AmmVœJApVa_mx Low Hazard"V_V^A]LA^ATNNxiNJpNL_a]ammaS]VSNx 1VT_VœJA_pA|AlL: Potential for property damage and economic disruption.x High Hazard !V\N]y pa lNmq]p V_ ]amm aS ]VSN A_L mVT_VœJA_p LA^ATN pa JlVpVJA] infrastructure.
x xplN^N]yVTUA|AlL1%]AmmVœJApVa_ : Could cause large-scale fatalities A_LV_q_LApNAlNAmwVpUavNllNmVLN_pm
VvN_pUNiaiq]ApVa_LN_mVpyaS!am_TN]Nmaq_pyALA^SAV]qlNJ]AmmVœNLAmVTUalxplN^N]yVTUA|AlLwaq]L]V\N]yJAqmNmqImpA_pVA]Uq^A_JAmqA]pVNmLVmi]AJNN_pVlNJa^^q_VpVNmA_LV_ŔVJpmNvNlNNJa_a^VJA_LN_vVla_^N_pA]LA^ATNTable 6-3 and 6-4 below shows a list of dams and debris basins owned by PW along with their hazard J]AmmVœJApVa_m-apN_pVA]^VpVTApVa_AJpVa_mLNmJlVINLV_pUVm"-AlNa_]yAii]VJAI]N to the dams and debris basins owned by PW and implementation of these actions arethe responsibility of the PW Stormwater Engineering Division – Dams Section.
County of Los Angeles
All-Hazards Mitigation Plan
Table 6-3: Los Angeles County PW Dam Hazard Status
Dam Name Hazard Status >ŽĐĂƟŽŶŝŐĂůƚŽŶ
džƚƌĞŵĞůLJ,ŝŐŚ 'ůĞŶĚŽƌĂ͕ŝŐ^ĂŶƚĂŶŝƚĂ
džƚƌĞŵĞůLJ,ŝŐŚ DŽŶƌŽǀŝĂ͕ŝŐdƵũƵŶŐĂEŽ͘ϭ
džƚƌĞŵĞůLJ,ŝŐŚ dƵũƵŶŐĂ͕ŽŐƐǁĞůů
džƚƌĞŵĞůLJ,ŝŐŚ njƵƐĂ͕ĞǀŝůƐ'ĂƚĞ
džƚƌĞŵĞůLJ,ŝŐŚ >ĂŶĂĚĂ&ůŝŶƚƌŝĚŐĞ͕>ŝǀĞKĂŬ
džƚƌĞŵĞůLJ,ŝŐŚ >ĂsĞƌŶĞ͕DŽƌƌŝƐ
džƚƌĞŵĞůLJ,ŝŐŚ njƵƐĂ͕WĂĐŽŝŵĂ
džƚƌĞŵĞůLJ,ŝŐŚ WĂĐŽŝŵĂ͕WƵĚĚŝŶŐƐƚŽŶĞ
džƚƌĞŵĞůLJ,ŝŐŚ ^ĂŶŝŵĂƐ͕WƵĚĚŝŶŐƐƚŽŶĞŝǀĞƌƐŝŽŶ ,ŝŐŚ >ĂsĞƌŶĞ͕^ĂŶŝŵĂƐ džƚƌĞŵĞůLJ,ŝŐŚ >ĂsĞƌŶĞ͕^ĂŶ'ĂďƌŝĞůEŽ͘ϭ
džƚƌĞŵĞůLJ,ŝŐŚ njƵƐĂ͕^ĂǁƉŝƚ
džƚƌĞŵĞůLJ,ŝŐŚ DŽŶƌŽǀŝĂ͕^ŝĞƌƌĂDĂĚƌĞ ,ŝŐŚ ^ŝĞƌƌĂDĂĚƌĞ͕dŚŽŵƉƐŽŶƌĞĞŬ džƚƌĞŵĞůLJ,ŝŐŚ ůĂƌĞŵŽŶƚ͕
Table 6-4: Los Angeles County PW Debris Basin Hazard Status Debris Basin Name Hazard Status >ŽĐĂƟŽŶĂŝůĞLJĞďƌŝƐĂƐŝŶ ,ŝŐŚ ^ŝĞƌƌĂDĂĚƌĞ͕ŝŐĂůƚŽŶĞďƌŝƐĂƐŝŶ ,ŝŐŚ 'ůĞŶĚŽƌĂ͕ůĂŶĐŚĂƌĚĞďƌŝƐĂƐŝŶ ,ŝŐŚ dƵũƵŶŐĂ͕ƌĂŶĚĞďƌŝƐĂƐŝŶ ,ŝŐŚ 'ůĞŶĚĂůĞ͕ ĂƚŽŶtĂƐŚĞďƌŝƐĂƐŝŶ
džƚƌĞŵĞůLJ,ŝŐŚ WĂƐĂĚĞŶĂ͕>ĂdƵŶĂĞďƌŝƐĂƐŝŶ
džƚƌĞŵĞůLJ,ŝŐŚ ^ƵŶsĂůůĞLJ͕>ĂŐƵŶĂZĞŐƵůĂƟŶŐĂƐŝŶ ^ŝŐŶŝĮĐĂŶƚ ůŚĂŵďƌĂ͕>ŝƩůĞĂůƚŽŶĞďƌŝƐĂƐŝŶ džƚƌĞŵĞůLJ,ŝŐŚ 'ůĞŶĚŽƌĂ͕>ŽǁĞƌ^ƵŶƐĞƚĞďƌŝƐĂƐŝŶ ,ŝŐŚ ƵƌďĂŶŬ͕DŽƌŐĂŶĞďƌŝƐĂƐŝŶ ,ŝŐŚ 'ůĞŶĚŽƌĂ͕ZƵďŝŽĞďƌŝƐĂƐŝŶ ,ŝŐŚ ůƚĂĚĞŶĂ͕^ĂŶƚĂŶŝƚĂĞďƌŝƐĂƐŝŶ >Žǁ ƌĐĂĚŝĂ͕^ĂǁƉŝƚĞďƌŝƐĂƐŝŶ džƚƌĞŵĞůLJ,ŝŐŚ DŽŶƌŽǀŝĂ͕
County of Los Angeles All-Hazards Mitigation Plan
Debris Basin Name Hazard Status >ŽĐĂƟŽŶ^ĐŚŽŽůŚŽƵƐĞĞďƌŝƐĂƐŝŶ ,ŝŐŚ >ŽƐŶŐĞůĞƐ͕^ŝĞƌƌĂDĂĚƌĞsŝůůĂ džƚƌĞŵĞůLJ,ŝŐŚ ^ŝĞƌƌĂDĂĚƌĞ͕^ƚĞǀĞŶƐŽŶZĂŶĐŚ ,ŝŐŚ ^ƚĞǀĞŶƐŽŶZĂŶĐŚ͕^ƚŽƵŐŚĞďƌŝƐĂƐŝŶ džƚƌĞŵĞůLJ,ŝŐŚ ƵƌďĂŶŬ͕tŝůƐŽŶĞďƌŝƐĂƐŝŶ ,ŝŐŚ >ŽƐŶŐĞůĞƐ͕
6.7.4 History Los Angeles County has experienced one of the deadliest dam failures in U.S. history: x St. Francis Dam Failure (March 12- o Released 12.4 billion gallons of water o At least 411 fatalities o Devastated towns from San Francisquito Canyon to Ventura County o Resulted in sweeping changes to California dam safety regulations and the creation of state oversight for civil engineers
:UV]N_a^A[alLA^SAV]qlNmUAvNaJJqllNLV_ lNJN_pLNJALNm Ja_JNl_mavNl ATV_TLA^V_SlAmplqJpqlNmNVm^VJlVm\mA_LV_JlNAmV_TJ]V^ApNvAlVAIV]VpyUAvNlAVmNLA]Al^mAIaqpSqpqlNlVm\m1pqLVNmV_LVJApN pUAp^A_yA]VSal_VALA^mV_J]qLV_T pUamNV_!am_TN]Nm aq_py lNkqVlN mplqJpqlA] qiLApNm pa wVpUmpA_L ^aLNl_ UyLla]aTVJA]conditions and potential seismic activity. There have been no federal declarations or mpApNilaJ]A^ApVa_mSalLA^SAV]qlNV_pUN]AmpœvNyNAlm6.7.5 Dam Coordination Los Angeles County Public Works JaalLV_ApNmwVpU]aJA]mpApNA_LSNLNlA]ATN_JVNmpa^VpVTApNŔaaLlVm\UA|AlLmpaLaw_mplNA^Ja^^q_VpVNmSla^VpmLA^mppUN]aJA]]NvN]PW works with cities and public agencies during development of Emergency Action -]A_m - 3UVmilavVLNm]aJA]mpA\NUa]LNlmwVpU pUNaiialpq_Vpy palNvVNw pUN-ilavVLNSNNLIAJ\A_LJa_œl^lNmia_mVIV]VpVNmA_Lla]NmLqlV_TA_-AJpVvApVa_prequest from local [qlVmLVJpVa_m PW ^Ay ilavVLN paqlm aS Vpm LA^ SAJV]VpVNm wUNlNinformation on dam safety and the potential hazards associated with dam failures are shared. ppUNmpApN]NvN]PW works with the DSOD to meet compliance with state dam safety mpA_LAlLm A_L ŔaaL ^A_ATN^N_p Ap A]] aS PW’s dams. This includes annual dam County of Los Angeles
All-Hazards Mitigation Plan
V_miNJpVa_m lNvVNw AiilavA] A_LavNlmVTUpaSLA^ Ja_mplqJpVa_ila[NJpm lNvVNwaSLA^mASNpy^a_VpalV_TA_LavNlmVTUpaSapUNlLA^mASNpylNTq]ApalyAJpVvVpVNmPW also JaalLV_ApNmwVpUvAlVaqmmpApNATN_JVNmV_J]qLV_T1%A]%1A_LA]plA_mLqlV_Tdevelopment of EAPs. ppUNSNLNlA]]NvN]PW works with the Federal Energy Regulatory Commission (FERC) pa^NNpJa^i]VA_JNwVpUmpApNLA^SNLNlA]mpA_LAlLmA_LŔaaL^A_ATN^N_pApPW’s 1A_ AIlVN] A^ wUVJU Vm q_LNl 0 [qlVmLVJpVa_ 3UVm V_J]qLNm A__qA] LA^V_miNJpVa_m lNvVNw AiilavA] A_LavNlmVTUpaSLA^ Ja_mplqJpVa_ila[NJpm lNvVNwaSLA^mASNpy^a_VpalV_T-JaalLV_ApVa_A_LavNlmVTUpaSapUNlLA^mASNpylNTq]Apalyactivities. PW also coordinates with the United States Army Corps of Engineers (USACE) on operations of interconnected dam facilities and emergency response planning for USACE facilities that may be in the pathway of dam failure impacts. Information Sharing PW ilavVLNm JlVpVJA] V_Sal^ApVa_ pa lN]NvA_p ]aJA] mpApN A_LSNLNlA] mpA\NUa]LNlm paaddress hazard mitigation related to dam safety. This includes:
x Emergency Action Plans (EAPs): -maqp]V_N pUN la]Nm lNmia_mVIV]VpVNm A_L procedures to follow in the event of a dam emergency. The EAPs include V_q_LApVa_^Aim wUVJU mUaw AlNAm pUAp waq]L IN ASSNJpNL Iy A LA^SAV]qlNhelping to identify populations at risk. These plans are shared with stakeholders to ensure a coordinated response. Due to the sensitive nature of information Ja_pAV_NLwVpUV_pUN-mpUNyAlNJa_œLN_pVA]A_L_aplN]NAmNLpapUNTN_NlA]public. x Inundation Maps: Inundation maps are critical tools for identifying areas and populations at risk in the event of a dam failure. They also indicate potential V^iAJpm a_ JlVpVJA] V_SlAmplqJpqlN SAJV]VpVNm mqJU Am UamiVpA]m mJUaa]m A_Ltransportation networks. These maps are shared with relevant stakeholders recognized in the EAP and are available to the general public through the DSOD Dam Breach Inundation Map Web Publisher.
6.7.6 Probability Los Angeles County contains over 90 state-[qlVmLVJpVa_A]LA^mwVpUAiilaxV^ApN]yJ]AmmVœNLAmVTUalxplN^N]yVTUA|AlLIypUNA]VSal_VAVvVmVa_aS1ASNpyaSA^m1% ^NA_V_T pUNVl SAV]qlN Jaq]L lNmq]p V_ ]amm aS ]VSN A_L mVT_VœJA_p ilaiNlpy damage.
County of Los Angeles All-Hazards Mitigation Plan
]pUaqTUJa^ilNUN_mVvNSAV]qlNilaIAIV]VpVNmAlN_apiqI]VmUNLSalNAJULA^"and DSOD guidance suggest that the general annual probability of failure for High A|AlL LA^m _ApVa_wVLN lA_TNmSla^ È pa È al V_ pa V_ depending on ^AV_pN_A_JNATNmNVm^VJvq]_NlAIV]VpyA_LapUNlmVpN-miNJVœJSAJpalmApplying this range to Los Angeles County:
x 3UN ATTlNTApN A__qA] ilaIAIV]Vpy aS A mVT_VœJA_p LA^ SAV]qlN NvN_p V_ pUN county—across one or more of the 70 high-risk dams—is estimated at between È A_L È A__qA]]y SAJpalV_T Jq^q]ApVvN NxiamqlN A_L LVSSNlN_p UA|AlLJ]AmmVœJApVa_m1qJUAmNAlpUkqA\NalŔaaLlN]ApNL x ]V^ApNJUA_TNATV_TV_SlAmplqJpqlNA_LmNVm^VJAJpVvVpyV_!am_TN]Nmaq_py increase systemic risk across multiple structures simultaneously. _mq^^AlywUV]NpUNV_LVvVLqA]]V\N]VUaaLaSSAV]qlNSalA_ya_NLA^VmvNly]awpUNoverall countywide probability of at least one major dam failure event is low but still wAllA_pmJa_pV_qNLvVTV]A_JN^AV_pN_A_JNA_LN^NlTN_Jyi]A__V_T
6.7.7 Vulnerability A catastrophic dam failure in Los Angeles County could have severe consequences for Uq_LlNLm aS pUaqmA_Lm aS lNmVLN_pm 3UN LN_mN]y iaiq]ApNL _ApqlN aS pUN Jaq_pycombined with the location of several large dams near residential and commercial AlNAmV_JlNAmNmpUNiapN_pVA]SalwVLNmilNALLVmi]AJN^N_p]ammaS]VSNA_LNJa_a^VJLA^ATN3UN30VLN_pVœNm^q]pVi]NUVTU-risk zones where dam failure could lNmq]pV_NxpN_mVvNŔaaLV_TA_L^AmmNvAJqApVa_m x High-lVm\LA^m A^a_TapUNlmiamNAmVT_VœJA_p pUlNAp paLN_mN]yiaiq]ApNL communities. A breach in any of these dams could inundate entire _NVTUIalUaaLm ASSNJpV_T^alN pUA_ lNmVLN_pmV_]aw-lying areas and ŔaaLi]AV_m
x 1aJVA]]y vq]_NlAI]N iaiq]ApVa_m V_J]qLV_T N]LNl]y V_LVvVLqA]m pUN # Ja^^q_VpyiNai]NNxiNlVN_JV_TUa^N]Nmm_Nmm]aw-V_Ja^NJa^^q_VpVNmA_Lnon-English-speaking residents face heightened risks during evacuations and lNJavNlyLqNpa]V^VpNL^aIV]Vpyœ_A_JVA]Ja_mplAV_pmA_LAJJNmmpalNmaqlJNm x LqJApVa_A]A_LUNA]pUJAlNV_mpVpqpVa_mAlNAplVm\wVpUmNvNlA]mJUaa]mUamiVpA]m and long-pNl^JAlNSAJV]VpVNm]aJApNLV_ŔaaL-prone areas. A major dam failure Jaq]L lNmq]p V_ mJUaa] J]amqlNm LVmi]AJN^N_p aS mpqLN_pm A_L LVmlqipVa_ aShealthcare services.
County of Los Angeles
All-Hazards Mitigation Plan
x vAJqApVa_A_LN^NlTN_JymUN]pNlV_TLN^A_Lmwaq]LINmqImpA_pVA]lNkqVlV_T the rapid mobilization of resources to support displaced residents. Temporary mUN]pNlmN^NlTN_Jy^NLVJA]mNlvVJNmA_Llogistical support would need to be activated to accommodate evacuees. !am _TN]Nm aq_py lN]VNm UNAvV]y a_ LA^m A_L lNmNlvaVlm Sal wApNl mpalATN ŔaaLJa_pla]A_Lmqii]y lNTq]ApVa_ApAmplaiUVJLA^SAV]qlNiamNmA_AJqpN pUlNAp pa]VSNA_LilaiNlpyNmiNJVA]]yV_]aw-]yV_TUVTU]yiaiq]ApNLLaw_mplNA^AlNAm Extent of Exposure
x Total Area Exposed: 490.64 sq mi x Supervisorial Districts (SD) Impacted:
o SD5: 223.88 sq mi (7.97%) o SD1: 162.25 sq mi (45.98%) o SD2: 66.57 sq mi (18.32%) o SD3: 25.76 sq mi (5.97%) o SD4: 12.17 sq mi (5.72%) x Critical Facilities Affected:
o Fire Department: 112 (33.22%) o Public Works: 92 (40.00%) o Health Services: 29 (44.62%) o Public Health: 17 (42.50%) o Libraries: 30 (34.48%) o Parks: 65 (35.50%) o Education: 34 (41.46%) Problem Statement Dam SAV]qlN wUV]N lAlN JA_ UAvN JApAmplaiUVJ Ja_mNkqN_JNm V_ LN_mN]y iaiq]ApNL Law_mplNA^ AlNAm :VpU mVT_VœJA_p ialpVa_m aS JlVpVJA] V_SlAmplqJpqlN NxiamNL— particularly in SD1 and SD5—i]A__V_T Sal N^NlTN_Jy NvAJqApVa_m NAl]y wAl_V_TmympN^mV_SlAmplqJpqlNUAlLN_V_TA_LLaw_mplNA^LNvN]ai^N_plNTq]ApVa_VmJlVpVJA]to saving lives and reducing loss.
County of Los Angeles All-Hazards Mitigation Plan
A failure or breach of a High Hazard Potential Dam (HHPD) in Los Angeles County waq]L lNmq]p V_ JApAmplaiUVJ Ja_mNkqN_JNm Sal Law_mplNA^ Ja^^q_VpVNm wVpU pUNgreatest vulnerabilities concentrated in densely populated urban areas. Rapid and ^AmmVvN ŔaaLV_T waq]L ]V\N]y V_q_LApN lNmVLN_pVA] _NVTUIalUaaLm Ja^^NlJVA]LVmplVJpm A_L V_LqmplVA] |a_NmwVpUV_^V_qpNm pa Uaqlm LNiN_LV_T a_ ilaxV^Vpy A_Ltopography. Critical infrastructure—V_J]qLV_TUamiVpA]mœlNA_Lia]VJNmpApVa_mmJUaa]mand major transportation corridors—waq]L IN mNvNlN]y V^iAJpNL LVmlqipV_TN^NlTN_JymNlvVJNmA_LNvAJqApVa_laqpNm3UaqmA_LmaSiNai]NV_J]qLV_Tvq]_NlAI]Niaiq]ApVa_mmqJUAmpUamNwVpUJJNmmA_Lq_JpVa_A]#NNLm# N]LNl]ylNmVLN_pmand low-V_Ja^N UaqmNUa]Lm wauld face immediate life-pUlNApN_V_T Ja_LVpVa_mLVmi]AJN^N_pA_L]V^VpNLAJJNmmpa^NLVJA]JAlNalmUN]pNlJa_a^VJ]ammNmwaq]LINJa^iaq_LNLIyLA^ATNpaqpV]VpVNmV_J]qLV_TiawNlmqImpApVa_mA_LwApNlmympN^mpotentially leaving large swaths of the region without essential services. The sheer scale aSLNvAmpApVa_Sla^ALA^SAV]qlNNmiNJVA]]yApSAJV]VpVNmmqJUAm:UVppVNl#AllawmalAmpAVJ A^ q_LNlmJalNm pUN JlVpVJA] V^ialpA_JN aS Ja_pV_qNL lVm\ lNLqJpVa_ NAl]ywAl_V_TmympN^mA_LLA^lNUAIV]Vtation efforts. 6.7.8 Data Limitations A limitation of this AHMP is that planning efforts only covered PW-owned dams in Los Angeles County. Future mitigation planning should include other dam owners and operators in Los Angeles County such as the US Army Corps of Engineers. The data on high-hazard dams reviewed during the 2025 AHMP planning process was generally suitable for the analysis required. Future opportunities for obtaining additional data to be considered in the next update to the plan should:
x Incorporate more current information as it becomes available. x Assess any new or updated EAPs for dams owned by Los Angeles County. x Identify and review more current structural or condition assessment data to inform future risk assessments.
x Involve other dam owners within Los Angeles County in future planning efforts.
6.7.9 Impacts A dam failure in Los Angeles County would have catastrophic and immediate Ja_mNkqN_JNmSal]VSNilaiNlpyA_L JlVpVJA]V_SlAmplqJpqlNiAlpVJq]Al]yV_ pUNLN_mN]ypopulated downstream areas. The sudden release of impounded water from a High or Extremely HVTUA|AlLLA^Jaq]LV_q_LApN_NVTUIalUaaLmwVpUV_^V_qpNmA]]awV_T]Vpp]Npa_apV^NSalNvAJqApVa_"alNpUA_ lNmVLN_pm]VvNwVpUV_VLN_pVœNLLA^V_q_LApVa_ |a_Nm ^A_y aS wUa^ AlN V_ maJVA]]y vq]_NlAI]N iaiq]ApVa_m—including County of Los Angeles
All-Hazards Mitigation Plan
V_LVvVLqA]m wVpU ]V^VpNL ^aIV]Vpy ]aw-V_Ja^N UaqmNUa]Lm A_L iNai]N NxiNlVN_JV_Thomelessness—making rapid evacuation and sheltering especially challenging. County-owned high hazard potential dams and their locations are listed in Table 6-3. Inundation maps for County-owned high hazard potential dams are listed in Appendix A-7.Critical infrastructure is also at mVT_VœJA_plVm\amiVpA]mœlNmpApVa_m]AwN_SalJN^N_pSAJV]VpVNm N^NlTN_Jy aiNlApVa_m JN_pNlm mJUaa]m A_L wAmpNwApNl plNAp^N_p i]A_pm ]aJApNL V_ Law_mplNA^ |a_Nm ^Ay IN LA^ATNL al lN_LNlNL V_aiNlAI]N mNvNlN]y disrupting emergency response and life-sustaining services. Major transportation laqpNmmqJUAmV_pNlmpApNmlAV]]V_NmA_LAlpNlVA]laALmJaq]LINmqI^NlTNLalwAmUNLaqp V^iNLV_T lNmJqN A_L lNJavNly NSSalpm LLVpVa_A]]y iawNl mqImpApVa_m wApNlLVmplVIqpVa_ _Npwal\m A_L pN]NJa^^q_VJApVons infrastructure could suffer cascading SAV]qlNmJa_plVIqpV_TpawVLNmilNALaqpATNmA_Lila]a_TNLlNJavNlyiNlVaLmThe economic consequences of dam failure would be immense. Beyond property LA^ATN IqmV_Nmm aiNlApVa_m V_ V_q_LApNL AlNAm waq]L UA]p ]NALV_T pa ]amm aSN^i]ay^N_ppAxlNvN_qNA_LNJa_a^VJAJpVvVpy_LqmplVA]|a_NmNmiNJVA]]ypUamN_NAl^A[al ŔaaL Ja_trol reservoirs or channels) could potentially release hazardous ^ApNlVA]mVSavNlwUN]^NLiamV_TmNJa_LAlyN_vVla_^N_pA]A_LiqI]VJUNA]pUUA|AlLmNIlVm AJJq^q]ApVa_ mNLV^N_pApVa_ A_L Ja_pA^V_ApVa_ Jaq]L mNvNlN]y V^iAJpNJamympN^mwApNlkqA]VpyA_LŔaaLJa_pla]V_SlAmplqJpqlNLaw_mplNA^Ja^i]VJApV_Tboth emergency cleanup and long-term environmental recovery. VvN_pUNmJA]NaSiapN_pVA]V^iAJpmLA^SAV]qlNVmJa_mVLNlNLAmpAI]N]aw-probability but high-Ja_mNkqN_JNUA|AlLV_!am_TN]Nmaq_pylNkqVlV_TJa_pV_qNLV_vNmp^N_pV_mplqJpqlA]^VpVTApVa_N^NlTN_JyilNiAlNL_NmmA_LiqI]VJAwAlN_NmmpalNLqJNpUNseverity of its effects.
6.7.10 High Hazard Potential Dams Goals aA] _UA_JN lNmV]VN_JN AJlamm LA^LNIlVm IAmV_ V_SlAmplqJpqlN V_J]qLV_T UVTUUA|AlLiapN_pVA]LA^mA_LapUNlJlVpVJA]SAJV]VpVNmwVpUV_LA^V_q_LApVa_|a_NmaA]Encourage structural reinforcement or lNplaœpmSalATV_TA_Lvq]_NlAI]NLA^maA]Ensure all dams/ debris basins have updated Emergency Action Plans (where applicable) and updated dam inundation mapping consistent with state standards.
County of Los Angeles All-Hazards Mitigation Plan
6.7.11 Mitigation and Preparedness Los Angeles County and state agencies have implemented various mitigation efforts to reduce the risks associated with dam failures:
x 1plqJpqlA]0NV_SalJN^N_pm4iTlALV_TmiV]]wAymmplN_TpUN_V_TNAlpUN_LA^m A_LV^i]N^N_pV_TmNVm^VJlNplaœppV_T^NAmqlNm
x Emergency Action Plans (EAPs): Mandated by DSOD for all High and Extremely High hazard dams to guide evacuation and response efforts. x Early Warning Systems: ^ilavNL ŔaaL ^a_VpalV_T A_L Aqpa^ApNL A]Nlp systems to notify at-risk communities in real-time.
6.7.12 High Hazard Potential Dam Prioritization The risk assessment within the 2025 AHMP considers the county planning area’s vulnerability and potential impacts related to HHPDs. Mitigation actions and planning efforts that are related to mitigating long-term vulnerabilities to County-owned HHPDs will automatically be given a HIGH priority as described in the overall mitigation action prioritization criteria in Section 7.6. The County Departments responsible for V^i]N^N_pV_T pUN AmmaJVApNL ^VpVTApVa_ AJpVa_m A]a_T wVpU pUN ilValVpy iapN_pVA]funding saqlJNA_LNxiNJpNLpV^NSlA^NAlN]VmpNLV_1NJpVa_6.7.13 Summary Los Angeles County has 90 state-[qlVmLVJpVa_A] LA^m wVpU J]AmmVœNL Am VTU alxplN^N]yVTUUA|AlL^NA_V_TpUNVlSAV]qlNJaq]LlNmq]pV_wVLNmilNAL]ammaS]VSNA_LNJa_a^VJ LNvAmpApVa_ :UV]N lNTq]Apaly avNlmVTUp UAm V^ilavNL LA^ mASNpy ATV_TinfrAmplqJpqlN mNVm^VJ pUlNApm A_L V_JlNAmNL mpal^ V_pN_mVpy lN^AV_ JUA]]N_TNma_pV_qNLV_vNmp^N_pV_lNplaœpmNAl]ywAl_V_TmympN^mA_LN^NlTN_Jyi]A__V_TVmessential to mitigating the risk of catastrophic dam failures.
County of Los Angeles
All-Hazards Mitigation Plan
County of Los AngelesAll-Hazards M i itgat oin Plan6.8 Land Movement
6.8.1 Nature
Land movement refers to the downward ^avN^N_p aS laJ\ maV] al LNIlVm A]a_T Aslope due to gravity. This process can occur mqLLN_]yalTlALqA]]yavNlpV^NLNiN_LV_Ton contributing factors such as soil Ja^iamVpVa_ m]aiN mpAIV]Vpy A_L NxpNl_A]triggers. Land movement encompass a variety of movement types including ^qLŔawm laJ\SA]]m LNIlVm Ŕawm ]A_Lm]q^im ]A_L mqImVLN_JN A_L maV]^avN^N_p _ !am _TN]Nm aq_py pUNdiverse topography and geological formations make certain areas more prone to land ^avN^N_p iAlpVJq]Al]y LqlV_T iNlVaLmaS V_pN_mN ilNJViVpApVa_ mNVm^VJ AJpVvVpy alhuman land-qmN^aLVœJApVa_mClimate change exacerbates land movement by increasing the frequency and intensity of NxplN^N wNApUNl NvN_pm mqJU Am UNAvy lAV_SA]] A_L ŔaaLV_T wUVJU JA_ ]NAL paaccelerated erosion and heightened landslide risks.
County of Los AngelesAll-Hazards Mitigation Plan
!A_L^avN^N_paSpN_aJJqlV_ Ja_[q_JpVa_wVpUapUNl_ApqlA]UA|AlLmNxAJNlIApV_Ttheir impact. Some of the primary contributing factors include:x Seismic ActivityAlpUkqA\Nm JA_LNmpAIV]V|Nm]aiNm]NALV_T pa]A_L^avN^N_p A_LlaJ\SA]]m3UNSalJNaSmNVm^VJmUA\V_TJA_JAqmNmqLLN_SAV]qlNmiAlpVJq]Al]yV_areas with pre-existing instability. x NAvy 0AV_SA]] A_L ]aaLV_T: The likelihood of land movement increases after mqJJNmmVvNmpal^m-la]a_TNLalV_pN_mNlAV_SA]]mApqlApNmmaV]lNLqJV_TVpmJaUNmVa_and triggering slope failures. x Coastal Erosion:AvNmA_Lmpal^mqlTNNlaLNJaAmpA]J]VSSm]NALV_TpaV_mpAIV]Vpy A_L NvN_pqA] Ja]]AimN iAlpVJq]Al]y V_ AlNAm mqJU Am aq_py INAJUNm A_L JaAmpA]Ja^^q_VpVNm^A_yaSwUVJUUAvNilNvVaqm]yNxiNlVN_JNLmVT_VœJA_pNlamVa_ x :V]LœlNm!ammaSvNTNpApVa_LqNpaœlNmlNLqJNmpUNmaV]¯mAIV]VpypalNpAV_^aVmpqlN making slopes more susceptible to erosion and land movement during subsequent rain events. x Burn Scars:V]LœlNIql_mJAlmmVT_VœJA_p]yN]NvApNpUNlVm\aS]A_L^avN^N_pIy mplViiV_TpUN]A_LaSmpAIV]V|V_TvNTNpApVa_lNAmASSNJpNLIy^A[alœlNmmqJUAmpUN:aa]mNyVlN aIJApVlN
lVLTNVlN Apa_VlN
A_LPalisades Fire (2025) have shown increased susceptibility to land movement due to reduced soil stability and rapid runoff during rainstorms.
6.8.2 LocationLos Angeles County is home to multiple regions susceptible to land movement due to mpNNim]aiNmq_mpAI]NTNa]aTyA_LwNApUNliAppNl_m3UNA]VSal_VANa]aTVJA]1qlvNy(CGS) Landslide Susceptibility Map highlights high-risk areas. For a better visual replNmN_pApVa_ aS pUN !A_L "avN^N_p A|AlL wVpUV_ pUN ! aq_py i]A__V_T AlNAplease reference Appendix A for maps that show areas that are susceptible to land movement and recent burn scars.Potential land movement areas include (but are not limited to):x Santa Monica Mountainsx San Gabriel Mountainsx Sierra Pelona Mountainsx Baldwin Hillsx Puente Hills x Palos Verdes Hills
County of Los Angeles
All-Hazards Mitigation Plan
3UNmN AlNAm AlN iAlpVJq]Al]y vq]_NlAI]N LqN pa pUNVl mpNNi pNllAV_m wNA\ laJ\Sal^ApVa_m A_L UVmpaly aS m]aiN ^avN^N_p LLVpVa_A]]y Uq^A_ AJpVvVpVNm mqJU AmTlALV_T NxJAvApVa_ A_L Ja_mplqJpVa_ V_ pUNmN lNTVa_m JA_ SqlpUNl LNmpAIV]V|N pUNTlaq_LV_JlNAmV_TpUN]V\N]VUaaLaS]A_L^avN^N_plNAmV^iAJpNLIyiAmpwV]LœlNm\_aw_ Am Iql_ mJAlm AlN A]ma UVTU]y mqmJNipVI]N pa ]A_L ^avN^N_p Am pUN ]amm aSvegetation reduces soil stability and increases erosion risks during heavy rains. This is particulal]yJa_JNl_V_TV_wV]LœlN-prone areas such as the Santa Monica Mountains and pUN SaapUV]]m aS pUN 1A_ AIlVN] "aq_pAV_m wUNlN iamp-œlN ]A_L ^avN^N_p UAvN UVmpalVJA]]yJAqmNLmVT_VœJA_pLA^ATN
6.8.3 Extent 3UNNxpN_paS]A_L^avN^N_pV_!am_TN]NmVmmVT_VœJA_pA_LvAlVNLV_ŔqN_JNLIyVpmq_VkqNTNa]aTVJA]mNppV_TJJalLV_T pa pUN1!A_Lm]VLN1qmJNipVIV]Vpy"Aiapproximately 750 square miles (15.75%) of Los Angeles County fall within high-risk landslide zones. The highest concentrations of deep-seated landslide susceptibility are distributed as follows:
Table 6-5 Landslide Susceptibility Map
Area High-0Vm\!A_Lm]VLN?a_Nm mk^V]Nm Percentage of Total Land Area Los Angeles County 750.02 15.75% Unincorporated Areas 577.63 18.99% Supervisorial District 1 17.29 7.02% Supervisorial District 2 2.73 1.68% Supervisorial District 3 114.61 26.58% Supervisorial District 4 105.12 23.89% Supervisorial District 5 509.31 18.14% County of Los Angeles All-Hazards Mitigation Plan
6.8.4 History!A_L^avN^N_pUAvNUVmpalVJA]]y JAqmNLmVT_VœJA_pLA^ATNV_ !am_TN]Nmaq_pyaSpN_lNmq]pV_TV_ilaiNlpyLNmplqJpVa_V_SlAmplqJpqlNLA^ATNA_LlaALJ]amqlNmThere UAvNINN__aSNLNlA]LNJ]AlApVa_malmpApNilaJ]A^ApVa_mSalLA^SAV]qlNV_pUN]AmpœvNyears. Some of the most notable events include: x 1956 – Portuguese Bend Landslide: A massive landslide on the Palos Verdes Peninsula began in 1956 and remains active today. The movement of land has LVmi]AJNL Ua^Nm A_L V_SlAmplqJpqlN UVTU]VTUpV_T pUN lNTVa_¯m a_TaV_T TNa]aTVJinstability. x 1994 – #alpUlVLTN AlpUkqA\N-Induced Land movement: The earthquake plVTTNlNL^alNpUA_^avV_TNvN_pmilV^AlV]yV_pUN1A_pA1qmA_A"aq_pAV_mA_L1A_AIlVN]"aq_pAV_mJAqmV_TNxpN_mVvNlaALA_LmplqJpqlA]LA^ATN x March 1995 – -AJVœJ -A]VmALNm !A_Lm]VLN: Heavy rains weakened the coastal I]qSSm ]NALV_T pa A -foot-wVLN Ja]]AimN pUAp IqlVNL iAlp aS pUN -AJVœJ aAmpHighway under 30 feet of debris. x March 2005 – Sunset Mesa Landslide: A slope failure near Malibu caused over JqIVJyAlLmaSLNIlVmpaI]aJ\laALwAymA_LLA^ATNilaiNlpy x July 2023 – -NAlplNN !A_N !A_L"avN^N_p 0a]]V_T V]]m mpApNm : A sudden m]aiNSAV]qlNlNmq]pNLV_pUNLVmi]AJN^N_paSUa^NmwUVJUwNlNlNL-tagged due to structural instability. x September 2024 – JJN]NlApNL !A_L "avN^N_p V_ 0A_JUa -A]am 9NlLNm: A mVT_VœJA_pV_JlNAmNV_]A_L^avN^N_pwVpUJNlpAV_AlNAmmUVSpV_TqipaSaqlV_JUNmiNlwNN\pawAlLpUNaJNA_pUlNApN_V_TlaALmA_LavNl lNmVLN_pVA]ilaiNlpVNm
6.8.5 Types of Land Movement Debris Flow"qLŔaw1aV]"avN^N_pNIlVmŔawV_va]vNm pUNlAiVL^avN^N_paSALN_mN^VxpqlNaSwApNlmaV]laJ\A_LalTA_VJ ^ApNlVA] Law_ A m]aiN 3UVm ilaJNmm JA_ UAvN mVT_VœJA_p V^iAJpm a_]A_LmJAiNmNJamympN^mA_LUq^A_V_SlAmplqJpqlNNIlVmŔawmAlNJUAlAJpNlV|NLIypUNVlŔqVL-like behavior and ability to transport large aI[NJpmmqJUAmIaq]LNlmA_LplNNm3UNyJA_plAvN]ApUVTUmiNNLm^A\V_TpUN^UVTU]yLNmplqJpVvN3UNJa^iamVpVa_aSALNIlVmŔawJA_vAlyIqpVppyiVJA]]yV_J]qdes:
County of Los Angeles
All-Hazards Mitigation Plan
x Water: A crucial component that facilitates movement. x 1aV]A_L0aJ\3UNmNilavVLNpUNIq]\aSpUN^ApNlVA]V_ALNIlVmŔawx Organic Material: Includes vegetation and other natural debris that get caught in pUNŔaw
"qLŔawm AlN lAiVL movements of water-saturated earth materials that can cause mVT_VœJA_pLA^ATN paIapU _ApqlA] N_vVla_^N_pm A_L Uq^A_ mNpp]N^N_pm"qLŔawmAlNJUAlAJpNlV|NLIypUNVlŔqVL-]V\N^apVa_wUVJUaJJqlmwUN_maV]laJ\mA_LLNIlVmbecome saturated with water. 3UVm mApqlApVa_ lNLqJNm pUNSlVJpVa_INpwNN_iAlpVJ]NmA]]awV_TpUN^Ammpa^avNLaw_UV]]q_LNlpUNV_ŔqN_JNaSTlAvVpy NyJUAlAJpNlVmpVJminclude: x 1iNNLA_L9a]q^N"qLŔawmJA_plAvN]ApmiNNLmqipa ^V]NmiNlUaqlA_L
JA_JAlly]AlTNva]q^NmaS^ApNlVA]V_J]qLV_TlaJ\mplNNmA_LNvN_vNUVJ]Nm x Consistency: 3UNJa_mVmpN_JyaSA^qLŔawJA_vAlySla^ApUVJ\vVmJaqmm]qllypa AwApNlyŔaw3UVmLNiN_Lma_pUNilaialpVa_aSwApNlpama]VL^ApNlVA]m x Path: "qLŔawmpyiVJA]]ySa]]awNxVmpV_TLlAV_ATNiAppNl_mmqJUAmlVvNlJUA__N]m A_LvA]]NymIqpJA_A]maJAlvN_NwiApUm]NALV_Tpaq_ilNLVJpAI]NA_LwVLNmilNALdamage. 1aV] ^avN^N_p Vm A _ApqlA] ilaJNmm pUAp mVT_VœJA_p]y V^iAJpm pUN N_vVla_^N_p A_Lhuman activities. It involves the displacement of soil particles due to various natural and human caused factors. Key characteristics include: x Landslides: %SpN_ aJJqllV_T V_ UV]]y AlNAm ]A_Lm]VLNm V_va]vN pUN Law_wAlL movement of rock and soil. They can be sudden and fast-^avV_T^A\V_T pUN^particularly dangerous. x Soil Creep: 3UVm Vm A m]aw A_L TlALqA] ^avN^N_p aS maV] Law_ A m]aiN aSpN_ q__apVJNLq_pV]mVT_VœJA_pLA^ATNaJJqlm
x 1aV] !VkqNSAJpVa_ qlV_T A_ NAlpUkqA\N mApqlApNL maV] JA_ pN^ialAlV]y ]amN Vpm mplN_TpUA_LINUAvN]V\NA]VkqVLJAqmV_TmplqJpqlNmpamV_\alpV]p Causes _ !am _TN]Nm aq_py mNvNlA] SAJpalm Ja_plVIqpN pa pUN aJJqllN_JN aS LNIlVmŔawm^qLŔawmmaV]^avN^N_px NAvy0AV_SA]]A_L1pal^vN_pm_pN_mNA_Lila]a_TNLlAV_SA]]aSpN_AmmaJVApNL wVpUmpal^mJA_mApqlApNpUNmaV]lNLqJV_TVpmmpAIV]VpyA_LplVTTNlV_TLNIlVmŔawm County of Los Angeles All-Hazards Mitigation Plan
3UN lNTVa_µm "NLVpNllA_NA_ J]V^ApN wVpU wNp wV_pNlm A_L Lly mq^^Nlm JlNApNmconditions conducive to such events. x :V]LœlNm !am _TN]Nm aq_py SlNkqN_p]y NxiNlVN_JNm wV]LœlNm wUVJU JA_ Iql_ and destabilize vegetation that normally helps hold soil in place. The loss of vNTNpApVa_V_JlNAmNmpUNlVm\aSmaV]NlamVa_A_LJa_mNkqN_p]yLNIlVmŔawmLqlV_Tsubsequent rainfalls. x Steep Terrain: 3UN Jaq_pyµm ^aq_pAV_aqm pNllAV_ V_J]qLV_T AlNAm ]V\N aq_py ^aq_pAV_aqmAlNAmVmiAlpVJq]Al]yila_NpaLNIlVmŔaw3UNmpNNim]aiNmSAJV]VpApNthe rapid movement of debris downhill. x Soil Composition: NlpAV_ maV] pyiNm mqJU Am J]Ay-lVJU maV]m JA_ INJa^N UVTU]y q_mpAI]NwUN_mApqlApNLwVpUwApNl^A\V_TpUN^^alNmqmJNipVI]NpaLNIlVmŔaw x Human Activity: 4lIA_ LNvN]ai^N_p laAL Ja_mplqJpVa_ A_L LNSalNmpApVa_ JA_ A]pNl_ApqlA]]A_LmJAiNmA_LNxAJNlIApNJa_LVpVa_mpUAp]NALpaLNIlVmŔaw x Seismic Activity: !am_TN]Nmaq_pyVmmVpqApNLV_ AUVTU]y AJpVvNmNVm^VJ |a_N ^A\V_T Vp ila_N pa NAlpUkqA\Nm 1NVm^VJ AJpVvVpy JA_ ]NAL pa maV] ]VkqNSAJpVa_]A_Lm]VLNmA_LTlaq_LmUA\V_TA]]Ja_plVIqpV_TpamaV]LVmi]AJN^N_p !A_L1qImVLN_JNLand subsidence is a gradual settling or sudden sinking of the Earth's surface due to various natural and human-V_LqJNLSAJpalm3UVmUA|AlLJA_UAvNmVT_VœJA_pV^iAJpma_pUNN_vVla_^N_pV_SlAmplqJpqlNA_LJa^^q_VpVNmlNLqJpVa_V_]A_LN]NvApVa_Vma_NaSpUN^amp_apVJNAI]NSNApqlNmaS]A_LmqImVLN_JN]NALV_T pamVT_VœJA_pJUA_TNmV_ pUN]A_LmJAiN3UVmiUN_a^N_a_JA_aJJqlLqN pa_ApqlA]ilaJNmmNmmqJUAmpUNLVmma]qpVa_aS]V^Nmpa_NAmwN]]AmUq^A_AJpVvVpVNmlike pUN NxJNmmVvN NxplAJpVa_ aS Tlaq_LwApNl aV] al _ApqlA] TAm qlpUNl^alN ]A_LmqImVLN_JNV_JlNAmNmpUNlVm\aSŔaaLV_TINJAqmNpUN]awNlN]NvApVa_JA_]NALpaiaalLlAV_ATNA_LwApNlAJJq^q]ApVa_mpUNTlaq_LmV_\mVpaSpN_lNmq]pmV_pUNSal^Apion aSLNilNmmVa_mœmmqlNmA_LmV_\Ua]NmwUVJUJA_LlA^ApVJA]]yA]pNlpUNTNaTlAiUyA_Linfrastructure of the area. x Depressions: Are sunken or low-]yV_TAlNAma_pUNAlpU¯mmqlSAJNaSpN_Sal^NLIy natural or man-made processes.
x Fissures: lNA]a_T_AllawJlAJ\al]V_NAlaiN_V_TV_pUNAlpU¯mJlqmpx 1V_\Ua]NmAre holes in the ground causes by the collapse or sinking of surface material into an underlying void.
County of Los Angeles
All-Hazards Mitigation Plan
Causes x laq_LwApNl xplAJpVa_One of the primary causes of land subsidence in Los Angeles County is the excessive extraction of groundwater. As water is pumped out aS q_LNlTlaq_L AkqVSNlm pUN Tlaq_L AIavN JA_ mV_\ al mNpp]N ]NALV_T pasubsidence. x %V]A_LAmxplAJpVa_The removal of oil and natural gas from beneath the earth's surface also contributes to land subsidence. This extraction can create voids and lNLqJNilNmmqlNV_mqIpNllA_NA_]AyNlmJAqmV_TpUNTlaq_LpamV_\ x Natural Soil Compaction: %vNl pV^N_ApqlA]ilaJNmmNmmqJU Am maV] Ja^iAJpVa_ can lead to gradual subsidence. In areas with loose or q_Ja_ma]VLApNL maV]m pUNwNVTUpaSavNl]yV_T^ApNlVA]mJa^iAJpmpUNTlaq_LlNmq]pV_TV_A]awNlV_TaSpUN land surface.
Rock Falls Rock falls are a natural geological phenomenon where rock fragments break free from a steep slope or cliff and tumble downward. These events can range from small iNII]Nm LVm]aLTV_T pa ^AmmVvN Iaq]LNlm JlAmUV_T Law_ wVpU mVT_VœJA_p SalJN A_Limpact. Rock falls are characterized by: x Speed and Suddenness: 0aJ\ SA]]m aJJql kqVJ\]y A_L wVpUaqp ^qJU wAl_V_T making them particularly dangerous.
x 9AlVNL1V|NmThe size of the falling material can range from small pebbles to large Iaq]LNlmV^iAJpV_TpUNmNvNlVpyaSpUNNvN_p
x Path Predictability: :UV]NpUNV_VpVA]plVTTNliaV_pVmaSpN_VLN_pVœAI]NpUNiApUaS descent can be unpredictable due to varying terrain and obstacles.
CausesThe primary causes of rock falls include: x Weathering and Erosion: %vNl pV^N wNApUNlV_T ilaJNmmNm mqJU AmSlNN|N-thaw JyJ]Nm JUN^VJA]wNApUNlV_TA_L pUN AJpVa_aSwApNl JA_wNA\N_ laJ\mplqJpqlNmlamVa_JA_q_LNl^V_NpUNIAmNaSm]aiNm^A\V_TlaJ\m^alNmqmJNipVI]NpaSA]]V_T x Seismic Activity: Los Angeles County is located in a seismically active region. AlpUkqA\NmJA_LVm]aLTNlaJ\mSla^J]VSSmA_LmpNNim]aiNmplVTTNlV_TlaJ\SA]]m County of Los Angeles All-Hazards Mitigation Plan
x NAvy0AV_SA]]_pN_mNalila]a_TNLlAV_SA]]JA_mApqlApNpUNTlaq_LV_JlNAmV_T the weight and pressure on rock faces. This saturation can lead to the loosening and collapse of rocks. x Human Activity: a_mplqJpVa_^V_V_TA_LapUNlUq^A_AJpVvVpVNmJA_LNmpAIV]V|N rock formations. The vibrations from heavy machinery and blasting can initiate rock falls.
6.8.6 Probability !A_Lm]VLNmA_LapUNl]A_L^avN^N_pNvN_pmUAiiN_V_!am_TN]Nmaq_pySAVl]yaSpN_NmiNJVA]]yASpNlUNAvylAV_alV_AlNAmpUAplNJN_p]yUALwV]LœlNmalAlNila_Npam]VLV_T x 1^A]]]A_Lm]VLNm]V\NLNIlVmŔawm AlN^amp]V\N]yLqlV_TyNAlmwVpUUNAvylAV_ NmiNJVA]]y]#V`ayNAlm3UNmNUAiiN_NvNlypayNAlmpUNlNVmÈpa Èchance each year during those cycles.
x In high-lVm\ |a_Nm ]V\N mpNNi ^aq_pAV_ m]aiNm wVpU A UVmpaly aS ^avN^N_p probability is 1–ÈJUA_JNiNlyNAlNmiNJVA]]ySa]]awV_T^q]pV-year wet periods al^A[alwV]LœlNm x Some areas of the County have been experiencing continuous sliding.
6.8.7 Vulnerability!A_L ^avN^N_p iamN lVm\m pa ]VSN ilaiNlpy A_L NmmN_pVA] V_SlAmplqJpqlN 3UN THIRA projects that approximately 1.2 million residents in Los Angeles County could be directly or indirectly affected by land movement. The most at-risk populations include: x 0NmVLN_pm aS UV]]mVLN A_L JA_ya_ Ja^^q_VpVNm mqJU Am"A]VIq3aiA_TA A_L pUN Palos Verdes Peninsula.
x Homeowners in coastal bluff areas that are facing erosion-driven slope failures. x a^^q_VpVNm V_ wV]LœlN Iql_ mJAl AlNAm wUNlN pUN ]amm aS vNTNpApVa_ V_JlNAmNm landslide probability during heavy rains.
x The Access and Functional Needs (AFN) community who may face challenges in evacuating or leaving landslide-prone areas.
County of Los Angeles
All-Hazards Mitigation Plan
Contextual Overview Los Angeles County’s diverse topography includes many hillside communities susceptible to deep-mNApNL ]A_Lm]VLNm NmiNJVA]]y ASpNl wV]LœlN al UNAvy lAV_ 3UNmNhazards can isolate Ja^^q_VpVNmLA^ATNilaiNlpyA_LLVmlqip]VSN]V_NmExtent of Exposure x Total Area Exposed: 284.57 sq mi x Supervisorial Districts (SD) Impacted:
o SD5: 151.96 sq mi (5.41%) o SD3: 90.23 sq mi (20.93%) o SD4: 25.94 sq mi (12.20%) o SD1: 13.77 sq mi (3.90%) o SD2: 2.68 sq mi (0.74%) x Critical Facilities Affected:
o Fire Department: 41 (12.17%) o Public Works: 32 (13.91%) o Health Services: 12 (18.46%) o Public Health: 4 (10.00%) o Libraries: 9 (10.34%) o Parks: 27 (14.92%) o Education: 8 (9.76%) Problem Statement !A_Lm]VLNmiamNAmNlVaqmlVm\paUV]]mVLNJa^^q_VpVNmA_LAJJNmmlaqpNmNmiNJVA]]yV_AlNAmlNJavNlV_TSla^wV]LœlNqllN_pLNvN]ai^N_pA_LlaALV_SlAmplqJpqlN^Ay_apbe resilient against slope failure. Mitigation actions should include slope stabilizApVa_pAlTNpNLIqyaqpmallN]aJApVa_mA_LNAl]ywAl_V_TmympN^m County of Los Angeles All-Hazards Mitigation Plan
6.8.8 Impacts Los Angeles County's diverse landscape and dense population make it highly mqmJNipVI]NpapUNNSSNJpmaS]A_L^avN^N_pASSNJpV_TJlVpVJA]V_SlAmplqJpqlNA_LlAVmV_TmVT_VœJA_pNJa_a^VJmaJVA]A_LmASNpyJa_JNl_m3lA_mialpApVa_#Npwal\m!am _TN]Nm aq_pyµm NxpN_mVvN plA_mialpApVa_ _Npwal\ Vm vVpA] Sal LAV]y Ja^^qpNmTaaLmplA_mialpA_LN^NlTN_JymNlvVJNm!A_L^avN^N_pJA_mNvNlN]yV^iAJppUNmNsystems: x 0aALA^ATNAqmNmJ]amqlNmhazardous driving conditions and costly repairs AmmNN_A__qA]]ya_-AJVœJaAmpVTUwAy- A_L^A_yapUNl]aJA]laALm x Bridge Compromise SSNJpm mplqJpqlA] V_pNTlVpy _NJNmmVpApV_T J]amqlNm A_L expensive reconstructions.
x Public Transit Disruptions^iAJpmplAV_plAJ\mA_LIqmlaqpNm]NALV_TpaLN]Aym and service interruptions.
x 0AV] 1ympN^m 3lAJ\ ^VmA]VT_^N_p JA_ JAqmN LN]Aym A_L iapN_pVA] LNlAV]^N_pm affecting both passenger and freight lines.
Water Supply Systems The county's water delivery system is complex and vulnerable to land movement: x Compromised Pipelines !NALm pa lqipqlNm al ]NA\m LVmlqipV_T mqii]y A_L requiring major repairs.
x 0NmNlvaVl^iAJp: Landslides can affect water quality and storage capacity. Energy Infrastructure !A_L^avN^N_piamNmlVm\mpa!am_TN]Nmaq_pyµmN_NlTyV_SlAmplqJpqlNV_J]qLV_Tx ]NJplVJA] lVL 9q]_NlAIV]VpVNm Land movement can damage power lines and mqImpApVa_mJAqmV_TaqpATNm
x Am-ViN]V_N0Vm\m1aV]mUVSpmJA_lNmq]pV_TAm]NA\malNxi]amVa_mN_LA_TNlV_T safety.
County of Los Angeles
All-Hazards Mitigation Plan
Communication Systems 0N]VAI]NJa^^q_VJApVa_VmJlVpVJA]A_L]A_L^avN^N_pJA_LVmlqip x Telecommunication Towers: Structural damage can impair cellular and internet services.
x Underground Cables: AlpUmUVSpmJA_LA^ATNJAI]NmASSNJpV_TJa__NJpVvVpy Emergency Services Facilities x Hospitals and Fire Stations: mmN_pVA] Sal N^NlTN_Jy lNmia_mN Iqp mplqJpqlA] LA^ATNJaq]LV^iNLNaiNlApVa_mq_LNlmJalV_TpUN_NNLSallNmV]VN_pJa_mplqJpVa_and strategic planning.
Economic Impacts x Infrastructure Damage: !NALmpaJamp]ylNiAVlmA_L^AV_pN_A_JNaSlaALmIlVLTNm and buildings.
x Property Loss: a^Naw_Nlm SAJN œ_A_JVA] ]ammNm LqN pa ilaiNlpy LA^ATN al devaluation.
Environmental Impacts x Ecosystem Disruption: Soil movement can lead to habitat loss A_LASSNJp]aJA]ŔalA and fauna.
x Increased Pollution: lamVa_JA_lNmq]pV_mNLV^N_plq_aSSLNTlALV_TwApNlkqA]Vpy in rivers and oceans.
For a better visual representation of the Land Movement Hazard within the LA County i]A__V_T AlNA i]NAmN lNSNlN_JN iiN_LVx for maps that show areas that are susceptible to land movement and recent burn scars.
6.8.9 Mitigation Strategies3alNLqJNpUNV^iAJpaS]A_L^avN^N_p!am_TN]Nmaq_pyUAmV^i]N^N_pNLmNvNlA]^VpVTApVa_A_LilNiAlNL_NmmmplApNTVNmV_J]qLV_Tx !A_L 4mN A_L NvN]ai^N_p 0NTq]ApVa_mRestricting development in high-risk landslide zones to prevent new structures from being built on unstable terrain. x _SlAmplqJpqlN 0NmV]VN_JN Reinforcing existing infrastructure through slope mpAIV]V|ApVa_ila[NJpmlNpAV_V_TwA]]mA_LV^ilavNLLlAV_ATNmympN^m County of Los Angeles All-Hazards Mitigation Plan
x 1pAIV]V|ApVa_ 0NTq]ApVa_m Implementing stricter grading and excavation regulations to minimize the destabilization of slopes.
x Public Awareness Campaigns: _UA_JV_T ]A_Lm]VLN NAl]y _apVœJApVa_m Iy monitoring potential movement areas and precipitation thresholds. x Evacuation Planning: Developing evacuation plans for at-lVm\ Ja^^q_VpVNm ensuring residents receive timely alerts and clear guidance. x Public Education: Conducting public education campaigns to inform residents about recognizing landslide warning signs and preparedness measures. x Operational Area Coordination_JlNAmV_TJaalLV_ApVa_AJlammmpApNSNLNlA]A_L %SœJN aS ^NlTN_Jy "A_ATN^N_p aSœJVA]m wVpU ]aJA] [qlVmLVJpVa_m pa V^ilavN forecasting and response efforts.
6.8.10 Summary!A_L ^avN^N_p lN^AV_m A mVT_VœJA_p UA|AlL V_ !am _TN]Nm aq_py iAlpVJq]Al]y V_mpNNiA_LJaAmpA]lNTVa_m3UN-A]am9NlLNm-N_V_mq]A1A_pA"a_VJA"aq_pAV_mA_L1A_AIlVN]"aq_pAV_mAlNA^a_TpUN^ampvq]_NlAI]NAlNAmwith climate change and human activities exacerbating risks. By implementing land-qmN lNTq]ApVa_mV_SlAmplqJpqlNlNV_SalJN^N_pmA_LN^NlTN_JylNmia_mNV^ilavN^N_pmpUNaq_pyJA_ enhance resilience and reduce losses in the future. Local governments and communities must actively monitor and manage contributing factors to effectively mitigate the impacts of land subsidence.
County of Los Angeles
All-Hazards Mitigation Plan
6.9 Tsunami6.9.1 NatureThis section characterizes tsunamis as high-N_NlTy ]a_T-wavelength ocean waves generated primarily by mVT_VœJA_p aSSmUalN mNVm^VJ NvN_pm(such as subduction zone NAlpUkqA\Nm mqI^AlV_N ]A_Lm]VLNmor volcanic eruptions. In the context of !am _TN]Nm aq_py pmq_A^Vmrepresent a relatively infrequent but potentially high-impact hazard that could produce rapid coastal inundation and surge impacts.Characteristics:x 3lVTTNlNL^AV_]yIyLVmpA_p]AlTNmagnitude seismic events.x Features long wavelengths and prolonged arrival times.x AiAI]NaSilaLqJV_TlAiVLLNNiV_q_LApVa_A]a_T]aw-lying coastal areas.x _mq^^Alypmq_A^VmAlNLy_A^VJ_ApqlA]iUN_a^N_AwVpUpUNiapN_pVA]paJAqmN mqLLN_JaAmpA]ŔaaLV_TA_LLA^ATNVSAplVTTNlV_TNvN_paJJqlm County of Los AngelesAll-Hazards Mitigation Plan
County of Los AngelesAll-Hazards Mitigation Plan
6.9.2 Location3UN qiLApNL pmq_A^V UA|AlL ilaœ]N SaJqmNm a_ pUN JaAmpA] areas of Los Angeles County. The new zone map—developed using enhanced modeling techniques and updated coastal geomorphology data—UVTU]VTUpmAlNAmA]a_TpUN-AJVœJmUalN]V_NpUApAlN Ap lVm\ 3UNmN V_J]qLN lNTVa_m AL[AJN_p pa pUN !am _TN]Nm AmV_ iAlpm aS !ang
NAJU1A_pA"a_VJA
AyA_LapUNl]aw-elevation coastal zones.For a better visual representation of Tsunami Inundation zones within the LA County i]A__V_TAlNAi]NAmNlNSNlN_JNiiN_LVxA for A¬3mq_A^V_q_LApVa_lNA map.Important Details:x Coastal segments from the western margins of the Los Angeles Basin extending to the border with Orange County.
%vNlA]] pUN coastal areas aS !am _TN]Nm aq_py containing our communities and infrastructureface heightened exposure.6.9.3 Extent4mV_T pUN ]ApNmp UyLlaLy_A^VJ A_L V_q_LApVa_ ^aLN]V_T pUN qiLApNL pmq_A^Vinundation (zone) ^AiilavVLNmAlNœ_NLvVNwaSpUNNxpN_paSiapN_pVA]ŔaaLV_T3UN^Ai V]]qmplApNm Uaw pmq_A^V wAvNm Jaq]L ilaiATApN V_]A_L mUawV_T lNvVmNLboundaries that account for current sea-level conditions and future sea-level rise projections.Highlights:x _q_LApVa_LNipUmA_LlNAJUUAvNINN_lNJA]Jq]ApNLwVpUma^NAlNAmiapN_pVA]]y experiencing water levels up to several feet in depth.
x 3UNV_]A_LlNAJUaSŔaaLV_TvAlVNmIy]aJA] paiaTlAiUywVpUŔAp]aw-lying areas showing the greatest potential for impacts ^iAJpNL AlNAm V_J]qLN Iqp AlN _ap]V^VpNLpa!a_T NAJU3UNialpmaS!a_T
NAJUA_L!am_TN]Nm"AlV_ALN]0NyVenice and Santa Monica. x lVpVJA] V_SlAmplqJpqlN wVpUV_ pUN qiLApNL |a_Nm UAm INN_ VLN_pVœNL pa ilValVpV|N mitigation and evacuation routes for planning.
_NmmN_JNpUNNxpN_paSpmq_A^VV^iAJpmVm_aw^AiiNL^alNilNJVmN]yaSSNlV_T]aJA]decision-^A\NlmAJ]NAlNlvVNwaSiapN_pVA]ŔaaLV_TLNipUmA_LLVmpA_JNmV_]A_L.
County of Los Angeles
All-Hazards Mitigation Plan
6.9.4 History VmpalVJA]]y mVT_VœJA_p pmq_A^V NvN_pm V_ pUN !am _TN]Nm lNTVa_ AlN lAlN pUaqTUdistant seismic events (for example: the 1960 Chilean tsunamialpUN^amplNJN_p Tonga tsunami) have been known to produce measurable impacts. Historical records combined with geological studies indicate that while tsunamis have occurred in the iAmppUNVlSlNkqN_JyVm]awJa^iAlNLpaapUNlUA|AlLmawNvNlpUNlNTVa_¯milaxV^Vpyto major tectonic boundaries necessitates ongoing vigilance. Historical Context:x Past events have been sporadic but can serve as valuable lessons for preparedness. x VmpalVJA] V_q_LApVa_ lNJalLm A_L mNLV^N_p mpqLVNm Ja_œl^ pUAp pmq_A^Vm UAvN reached the Los Angeles coast in prehistory.
x Lessons learned from past minor events underscore the importance of maintaining updated hazard maps.
3UqmwUV]NUVmpalVJA]pmq_A^VNvN_pmAlNV_SlNkqN_ppUNyilavVLNAJlVpVJA]Ja_pNxpSalunderstanding future risks and guiding preparedness measures. There have been no SNLNlA]LNJ]AlApVa_malmpApNilaJ]A^ApVa_mSalpmq_A^VV_pUN]AmpœvNyNAlm
6.9.5 Probability The probability of a tsunami affecting Los Angeles County is generally low when Ja^iAlNL pa ^alN SlNkqN_p UA|AlLm ]V\N NAlpUkqA\Nm al ŔaaLm #NvNlpUN]Nmm pUNpotential for a distance source pmq_A^V TN_NlApNL Iy A LVmpA_p large seismic event remains a realistic risk. Updated probabilistic assessments—incorporating recent seismic data and tsunami modeling V_LVJApNpUApwUV]NpUNavNlA]]]V\N]VUaaLVm]awpUNconsequences in the event of a tsunami can be severe. Probability Considerations: x Low annual probability but high consequence if an event occurs !am _TN]Nm County has about a 2% annual chance.
x Distance source events from subduction zones across the ocean contribute most to the risk.
x Continuous monitoring and updated modeling are essential to reassess the risk over time.
x _mq^^AlypUNilaIAIV]VpyaSApmq_A^VlN^AV_m]awIqpLqNpapUNiapN_pVA]Sal high-V^iAJpaqpJa^NmVpwAllA_pmJa_pV_qaqmmpqLyA_LilNiAlNL_Nmm County of Los Angeles All-Hazards Mitigation Plan
6.9.6 Vulnerability aAmpA]vq]_NlAIV]VpyV_!am_TN]Nmaq_pyVmmVT_VœJA_p]yV_ŔqN_JNLIySAJpalmmqJUAm qlIA_ LN_mVpy ]aw-N]NvApVa_ pNllAV_ ATV_T V_SlAmplqJpqlN A_L maJVa-economic conditions. The updated tsunami zone map now better delineates areas where these vulnelAIV]VpVNmAlN^ampila_aq_JNLUVTU]VTUpV_TJa^^q_VpVNmpUAp^AyUAvN]V^VpNLevacuation routes and fewer resources to recover from rapid inundation. Iaqp iNai]N]VvNV_iAlpmaS!am_TN]Nmaq_pypUApJaq]LINŔaaLNLIyApmq_A^V"A_ypeople a]ma wal\ V_ pUNmN JaAmpA] AlNAm A_L Alaq_L q_UaqmNL V_LVvVLqA]m ]VvNpUNlN^A\V_TpUN^NmiNJVA]]yAplVm\INJAqmNpUNy^Ay_apUAvNNAmyAJJNmmpamUN]pNlor transportation. 3aqlVm^ALLmNvN_^alNiNai]N pa pUNmNAlNAmNmiNJVA]]yLqlV_TIqmywNN\N_LmalUa]VLAym-]AJNm]V\N1A_pA"a_VJA JA_mNNqi pavVmVpalmALAyLqlV_TiNA\times. This makes evacuating harder if a tsunami warning is issued. Roads near the coast ca_kqVJ\]yINJa^NJlawLNLA_LvVmVpalm^Ay_ap\_awpUNINmpwAypa]NAvN3lASœJJaq]Lm]awLaw_N^NlTN_Jyi]A_mmaVp¯mV^ialpA_p paUAvNJ]NAlmVT_mNAl]ywAl_V_TmA_LTaaLplASœJJa_pla]paUN]iiNai]NTNppamASNpykqVJ\]yFactors:x High population density in low-lying coastal areas. x lVpVJA] V_SlAmplqJpqlN NT UamiVpA]m qpV]VpVNm ialpm A_L mUViiV_T transportation networks) located within the inundation zones.
x Socio-economic and language barriers that may hinder effective emergency response.
x Limited natural barriers in some coastal segments. x Vulnerable communities include those with high population densities and critical infrastructure near the coast.
4]pV^ApN]ypUNvq]_NlAIV]VpyaSpUNlNTVa_VmJa^iaq_LNLIyIapUiUymVJA]NxiamqlNmA_LmaJVA]SAJpalmq_LNlmJalV_TpUN_NNLSalpAlTNpNL^VpVTApVa_NSSalpmContextual Overview aAmpA]Ja^^q_VpVNmV_!am_TN]Nmaq_pyV_J]qLV_TialpmA_LpaqlVmp|a_NmAlNAprisk from tsunamis. These rare but highly destructive events can inundate coastal infrastructure with little warning.
County of Los Angeles
All-Hazards Mitigation Plan
Extent of Exposure
x Total Area Exposed: 32.89 sq mi x Supervisorial Districts (SD) Impacted:
o SD4: 15.83 sq mi (7.43%) o SD3: 12.59 sq mi (2.92%) o SD2: 2.03 sq mi (0.56%) x Critical Facilities Affected:
o Fire Department: 16 (4.75%) o Public Works: 9 (3.91%) o Health Services: 3 (4.62%) o Public Health: 1 (2.50%) o Libraries: 5 (5.75%) o Parks: 13 (7.26%) o Education: 3 (3.66%) Problem Statement 3mq_A^Vm JA_ JAqmN lAiVL A_L JApAmplaiUVJ JaAmpA] ŔaaLV_T :VpU JlVpVJA] JaAmpA]V_SlAmplqJpqlNA_LlNmVLN_pVA]AlNAmNxiamNLNmiNJVA]]yV_1A_L1pUNlNVmA_NNLSallaIqmpNvAJqApVa_i]A__V_TvNlpVJA]NvAJqApVa_mUN]pNlmA_LJa^^q_VpyaqplNAJUto enhance preparedness and reduce vulnerability.
6.9.7 Impacts 1Uaq]L A pmq_A^V aJJql pUN iapN_pVA] V^iAJpm a_ !am _TN]Nm aq_py Jaq]L INextensive. Parts of Los Angeles County that could be impacted by a Tsunami are Marina N]0Ny-alpaS!am_TN]Nm-alpaS!a_T NAJUA_LapUNlbeach communities in low lying areas. 3UNqiLApNLV^iAJpAmmNmm^N_pmlNŔNJpiammVI]NmJN_AlVamlA_TV_TSla^mVT_VœJA_pilaiNlpyLA^ATNpa]ammaS]VSNA_L]a_T-term economic disruption. The new zone map aids in quantifying these impacts by providing detailed inundation depths and spatia]NxpN_pmpUNlNIyA]]awV_TSalINppNllVm\Ja^^q_VJApVa_A_Li]A__V_T County of Los Angeles All-Hazards Mitigation Plan
Potential Impacts:x 1NvNlNŔaaLV_TaSJaAmpA]V_SlAmplqJpqlNA_LlNmVLN_pVA]AlNAmx VmlqipVa_aSplA_mialpApVa_qpV]VpymNlvVJNmA_LN^NlTN_JylNmia_mNaiNlApVa_mx Ja_a^VJ]ammNmV_\NymNJpalmmqJUAmpaqlVm^mUViiV_TA_L]aJA]Ja^^NlJNx 1aJVA] V^iAJpm V_J]qLV_T LVmi]AJN^N_p ]amm aS ]VvN]VUaaLm A_L JUA]]N_TNm V_ emergency sheltering.
_ mUalp pUN iapN_pVA] V^iAJpm aS A pmq_A^V AlN SAl-lNAJUV_T _NJNmmVpApV_T laIqmp^VpVTApVa_NvAJqApVa_A_LlNJavNlyi]A__V_Tpa^V_V^V|NUAl^For a better visual representation of Tsunami Inundation zones within the LA County i]A__V_TAlNAi]NAmNlNSNlN_JNiiN_LVx for A¬3mq_A^V_q_LApVa_lNA^Ai.
6.9.8 Summary The updated tsunami section for the 2025 AHMP V_JalialApNm pUN ]ApNmp mJVN_pVœJœ_LV_TmA_L^AiiV_TpNJU_VkqNmpailavVLNA^alNilNJVmNq_LNlmpA_LV_TaSpmq_A^VlVm\m V_ !am _TN]Nm aq_py y V_pNTlApV_T A_ qiLApNL V_q_LApVa_ |a_N ^Ai pUNlNvVmVa_ J]AlVœNm pUN miApVA] NxpN_p aS iapN_pVA] ŔaaLVng and highlights the vulnerabilities in coastal communities. This comprehensive update is designed to guide decision-^A\NlmV_N_UA_JV_TilNiAlNL_NmmpAlTNpV_T^VpVTApVa_mplApNTVNmA_Lstrengthening community resilience. Ny3A\NAwAymx Nature: Tsunamis are infrequent but high-energy events capable of rapid coastal inundation.
x Location & Extent: 3UNqiLApNL|a_N^AiVLN_pVœNmvq]_NlAI]NJaAmpA]AlNAmwVpU lNvVmNLV_]A_LŔaaLNxpN_pm
x History & Probability: VmpalVJA]NvN_pmAlNlAlNUawNvNldistance events remain a realistic risk.
x 9q]_NlAIV]Vpy Ë ^iAJpm High population density and critical infrastructure in JaAmpA]|a_NmA^i]VSylVm\wVpUiapN_pVA]SalmNvNlNNJa_a^VJA_LmaJVA]LVmlqipVa_ 3UVmqiLApNLmNJpVa_VmV_pN_LNLpamNlvNAmAJlVpVJA]paa]Salia]VJy^A\NlmN^NlTN_Jy^A_ATNlmA_LJa^^q_VpympA\NUa]LNlmAmpUNywal\paTNpUNlpalNLqJNpUN]a_T-term risks associated with tsunamis and enhance overall regional resilience.
County of Los Angeles
All-Hazards Mitigation Plan
County of LosA ngelesAll-Hazards Mitigation Plan6.10 Severe Wind and Tornado6.10.1 NatureSevere wind and tornadoes pose mVT_VœJA_p pUlNApm pa ]VSN ilaiNlpy A_LV_SlAmplqJpqlN pUaqTU pUNy LVSSNl V_frequency and intensity within Los Angeles aq_py 1NvNlN wV_L NvN_pm iAlpVJq]Al]y1A_pA _A wV_Lm AlN A lNJqllV_T _ApqlA]hazard that can cause widespread LA^ATN V_J]qLV_T Law_NL iawNl ]V_NmplNN SA]]m A_L mplqJpqlA] damage. These winds originate from high-pressure mympN^mavNlpUNlNAp AmV_Sq__N]V_TLlyand warm air through mountain passes into the coastal and valley regions at high speNLm LLVpVa_A]]y mpal^-LlVvN_ wV_Lm^VJlaIqlmpm straight-line winds and gust fronts associated with severe weather can JlNApNUA|AlLaqmJa_LVpVa_maSpN_]NALV_Tpa plA_mialpApVa_LVmlqipVa_m œlN UA|AlLmand prolonged power outages.
County of Los AngelesAll-Hazards Mitigation Plan
3al_ALaNm wUV]N lN]ApVvN]y lAlN V_ pUN lNTVa_ UAvN INN_ lNJalLNL A_L JA_ JAqmNlocalized but intense damage. These violent windstorms form when unstable Ap^amiUNlVJ Ja_LVpVa_m ilaLqJN lapApV_T qiLlASpm lNmq]pV_T V_ A Sq__N] J]aqL pUApcontacts the ground. 6.10.2 Location Severe wind events affect the entire Los Angeles County planning area wVpU pUNmpla_TNmpaJJqllN_JNmV_ JA_ya_iAmmNmvA]]NymA_L JaAmpA] lNTVa_m The Santa Ana wV_LmAlN^ampV_pN_mNV_pUNSA]]A_LwV_pNl^a_pUmiAlpVJq]Al]yV^iAJpV_TAlNAmin the 9A]]NyA_L foothill communities of the County. Storm-LlVvN_wV_Lma_pUNapUNlUA_Lcan impact any part of the county and vary in intensity based on weather patterns. 3UNmN wV_Lm JA_ lNAJU miNNLm aS pa ^iU ma^NpV^Nm NxJNNLV_T pUamNpUlNmUa]Lm]NALV_TpamVT_VœJA_pLA^ATNTornadoes are more sporadic in occurrence and can develop in various parts of the Jaq_pyiAlpVJq]Al]yV_]aw]A_LAlNAmwUNlNmNvNlNpUq_LNlmpal^mUAvNpUNiapN_pVA]paform rotating systems. 6.10.3 ExtentWinds and breezes are common occurrences in LA County. As wind speeds increase so does the potential for a catastrophic event. Hot dry winds can reach high speeds as pUNyLNmJN_LSla^pUNV_]A_LLNmNlplNTVa_mJlNApV_T_apa_]yJlVpVJA]wV_LNvN_pmIqpalmaNxplN^N]yLA_TNlaqmœlNJa_LVpVa_mA_LJa_plVIqpV_T pa pUNmilNALaSwV]LœlNm3UNwV_LmAlNJ]AmmVœNLV_pUN NAqSalp:V_L1JA]NmNNFigure 6.10.1 below. Beaufort wind scale is an empirical scale that relates wind speed to observed conditions at sea or land. It uses numerical scale from 1-12 to describe wind force based on visual observations of the effects of the wind and gives quantitative measures of the wind. For NxA^i]NaVmLNmJlVINLAm®JA]^¯AmNA]V\NA^VllalwUV]NLNmJlVINLAmUqllVJAne force with devastating conditions. 3al_ALaNm AlN J]AmmVœNL qmV_T pUN _UA_JNL q[VpA Scale Figure 6.10.2. The _UA_JNLq[VpA 1JA]NVmmiNJVœJA]]yqmNLpalApNpUNV_pN_mVpyaSpal_ALamIAmNLa_ pUNLA^ATN pUNy JAqmN LA^ATNV_LVJApalm mqJU AmIqV]LV_T pyiNm A_L plNNmpranges from EF-0 to EF- wVpU V_JlNAmV_T _q^INlm V_LVJApN mpla_TNl pal_ALam A_d more severe damage. While tornadoes in the region typically do not exceed EF-1 County of Los Angeles
All-Hazards Mitigation Plan
V_pN_mVpy pUNyJA_mpV]]ilaLqJNLA^ATV_TwV_LmAIavN^iUJAiAI]NaS pNAlV_TlaaSmaSSIqV]LV_TmqilaapV_TplNNmA_LavNlpql_V_TvNUVJ]NmBeaufort Wind Scale:
Force
Wind
(Knots)
WMO
Classification
Appearance of Wind Effects
On the Water On Land
0 Less than 1 Calm Sea surface smooth and mirror-like A]^m^a\NlVmNm vertically 1 1-3 Light Air 1JA]ylVii]Nm_aSaA^JlNmpm Smoke drift indicates wV_LLVlNJpVa_mpV]]wV_Lvanes
2 4-6 Light Breeze 1^A]]wAvN]NpmJlNmpmT]Ammy no breaking :V_LSN]pa_SAJN]NAvNm lqmp]NvA_NmINTV_pa move 3 7-10 Gentle Breeze !AlTNwAvN]NpmJlNmpmINTV_ paIlNA\mJAppNlNLwUVpNJAim Leaves and small twigs Ja_mpA_p]y^avV_T]VTUp flags extended 4 11-16 Moderate Breeze Small waves 1-4 ft. becoming ]a_TNl_q^NlaqmwUVpNJAim qmp]NAvNmA_L]aamN iAiNl]VSpNLm^A]]plNN branches move 5 17-21 Fresh Breeze Moderate waves 4-8 ft taking ]a_TNlSal^^A_ywUVpNJAimsome spray Small trees in leaf begin to sway
6 22-27 Strong Breeze Larger waves 8-Sp wUVpNJAimJa^^a_^alN spray
Larger tree branches ^avV_Twhistling in wires
7 28-33 Near Gale
1NAUNAimqiwAvNm-Spwhite foam streaks off breakers :Ua]NplNNm^avV_Tresistance felt walking against wind County of Los Angeles All-Hazards Mitigation Plan
8 34-40 Gale
Moderately high (18-25 ft) wAvNmaSTlNApNl]N_TpUedges of crests begin to IlNA\V_pamiV_LlVSpSaA^blown in streaks 3wVTmIlNA\V_TaSSplNNmgenerally impedes progress
9 41-47 Strong Gale
High waves (23-Sp mNAINTV_mpala]]LN_mNmplNA\maSSaA^milAy^AylNLqJNvisibility Slight structural damage aJJqlmm]ApNblows off roofs
10 48-55 Storm
Very high waves (29-41 ft) wVpUavNlUA_TV_TJlNmpmmNAwhite with densely blown SaA^UNAvyla]]V_T]awNlNLvisibility Seldom experienced on ]A_LplNNmIla\N_alqilaapNL´Ja_mVLNlAI]NmplqJpqlA]LA^ATN´ 11 56-63 Violent Storm
Exceptionally high (37-52 ft) wAvNmSaA^iApJUNmJavNlmNAvVmVIV]Vpy^alNlNLqJNL 12 64+ Hurricane
VlSV]]NLwVpUSaA^wAvNmavNl
SpmNAJa^i]NpN]ywUVpNwVpULlVvV_TmilAyvisibility greatly reduced Figure 6.10.1 ĞĂƵĨŽƌƚtŝŶĚ^ĐĂůĞ
County of Los Angeles
All-Hazards Mitigation Plan
Enhanced Fujita Scale:
THE ENHANCED FUJITA SCALE (EF SCALE)
03# 1NJa_Lqmp"- "
EF 0 65-85 MPH !VTUp
lA_JUNmIla\N_ minor roof damage EF 1 86-110 MPH
Moderate: Roofs
LA^ATNLplNNmqilaapNL
EF 2 111-135 MPH
Considerable: Roofs torn
aSS]AlTNplNNmLaw_
EF 3 136-165 MPH 1NvNlNa^NmLNmplayNL cars lifted EF 4 166-200 MPH Devastating: Houses ]NvN]NLLNIlVmAVlIal_NEF 5 Over 200 MPH Incredible: Homes swept away total destruction
6.10.4 History Los Angeles County has experienced multiple severe wind events and occasional tornadoes in recent history wUVJUJAqmNLLNmplqJpVa_mA_LwV]LœlNm. There have been no federal declarations or state proclamations for Severe Wind & Tornadoes in the last œvNyNAlm Some notable incidents include:
x November-December 2011: wV_LNvN_p JAqmNL^alN pUA_¸ ^V]]Va_V_
damages and severely impacted several foothill communities and unincorporated areas. x December 2019: An EF-pal_ALapaqJUNLLaw_V_1aqpU!am_TN]NmJAqmV_T minor roof damage and downing power lines.
x January 2021: mNvNlNwV_Lmpal^V^iAJpNLpUNlNTVa_]NALV_TpaLA^ATN across multiple communities and emergency response efforts to clear roadways. x September 2021: An EF-0 tornado developed near the community Lake of Los _TN]NmÈ_aLA^ATNwAmlNialpNL
Figure 6.10.2 Enhanced Fujita Scale
County of Los Angeles All-Hazards Mitigation Plan
x April 2023: An EF-0 tornado recorded in Cerritos causing tree damage. x March 2023 (0 ): An EF- pal_ALa mplqJ\ "a_pNIN]]a a_N aS pUN mpla_TNmp pal_ALaNm lNJalLNL V_ pUN AlNA JAqmV_T mVT_VœJA_p LA^ATN pacommercial structures and vehicles. x May 2023: An EF-0 tornado occurred near the communities of Carson and Compton damaging buildings and vehicles.
x August 2023 (0
): Tropical Storm Hillary impacting Los Angeles
County.
x February 2024: Strong winds impacting across Eastern Santa Monica Mountain and Santa Clarita Valley.
x March 2024: Strong winds impacting areas around San Gabriel Valley. x January 2025 (0 ): A mNvNlNwV_Lmpal^V^iAJpNLpUNlNTVa_]NALV_T
to a -apN_pVA]]y A_TNlaqm 1VpqApVa_ -1 lNL ŔAT Ja_LVpVa_m 1NvNlA] œlNmIla\NaqpV_pUNAlNAwUVJUNxUVIVpNLNxplN^NœlNINUAvValJAqmV_TwVLNmilNALdestruction. x March 2025 (0
): miAlpaSAmpal^NvN_pA_ EF-0 tornado struck Pico 0VvNlAA]VSal_VAAp
A^with wind speeds reaching up to 85 mph.
6.10.5 Probability 1NvNlN wV_L NvN_pm AlN A lNTq]Al aJJqllN_JN V_ !am _TN]Nm aq_py wVpU A Uigh probabilityÈJUA_JN recurring annually. Santa Ana winds are particularly common LqlV_TpUNJaa]Nl^a_pUmA_LJ]V^ApNiAppNl_mmqTTNmppUApNxplN^NwV_LNvN_pm^Aybecome more frequent due to changing weather dynamics. Because wind events and pal_ALam AlN ]aJA]V|NL V_ _ApqlN ilaIAIV]Vpy vAly Sla^ a_N AlNA pa A_apUNl A_L VmLVSœJq]ppaLNpNl^V_NiNlJN_pATNaSUAiiN_V_TV_a_NAlNATornadoes remain a lowprobability hazard10% chance in the planning areaUawNvNlTVvN_iAmpaJJqllN_JNmthey cannot be ruled out entirely. Atmospheric conditions capable of producing pal_ALaNm^AyAlVmNLqlV_TmNvNlNpUq_LNlmpal^miAlpVJq]Al]yV_wV_pNlmpal^mympN^mthat generate strong wind shear. While the likelihood of an EF-2 or stronger tornado is ^V_V^A]pUNiapN_pVA]Sal]aJA]V|NLLA^ATNlN^AV_m The Santa Ana winds occur ten to twenty-œvN pV^Nm A__qA]]y A_L JA_]AmpSal mNvNlA]LAymiamV_T A lNJqllV_T pUlNApaS damage and disruption in Los Angeles County.
County of Los Angeles
All-Hazards Mitigation Plan
6.10.6 Vulnerability SNvNlNwV_LA_Lpal_ALaNmJA_INNxpN_mVvNASSNJpV_TIapUV_SlAmplqJpqlNA_LiqI]VJsafety. High-wV_LNvN_pmiamNAlVm\ paJlVpVJA]V_SlAmplqJpqlNiAlpVJq]Al]yiawNl]V_NmJa^^q_VJApVa_ mympN^m A_L plA_mialpApVa_ _Npwal\m qV]LV_Tm NmiNJVA]]y a]LNlstructures and ^aIV]NUa^NmAlNvq]_NlAI]NpawV_L-lN]ApNLLA^ATNV_J]qLV_TlaaSSAV]qlNmwV_LawIlNA\ATNA_LmplqJpqlA]Ja]]AimN_ ALLVpVa_ pa iUymVJA] LA^ATN mNvNlN wV_L NvN_pm JA_ JAqmN mVT_VœJA_p NJa_a^VJLVmlqipVa_m -la]a_TNL iawNl aqpATNm V^iAJp IqmV_NmmNm UNA]pUJAlN SAJV]VpVNm A_Lemergency response services. Road closures and debris blockages hinder mobility and commercNwUV]NwV_L-LlVvN_wV]LœlNm A mNJa_LAlyUA|AlLaS 1A_pA_AwV_Lm JA_lead to devastating losses. -qI]VJ mASNpy Vm A]ma A ^A[al Ja_JNl_ wVpU lVm\m aS ŔyV_T LNIlVm vNUVJ]N AJJVLN_pmavNlpql_NL vNUVJ]Nm and respiratory issues caused by airborne dust and pollutants stirred up by high winds. Severe wind and tornado events disproportionately impact certain populations and infrastructure in Los Angeles County due to both geographic exposure and maJVaNJa_a^VJvq]_NlAIV]VpVNm3UNmNUA|AlLmJA_LVmlqipJlVpVJA]mNlvVJNmNxAJNlIApNexisting inequa]VpVNmA_LmVT_VœJA_p]yLA^ATNmplqJpqlNm_apIqV]ppawVpUmpA_LNxplN^Nwind conditions. 9q]_NlAI]N-aiq]ApVa_m%qp aS pUN Jaq_py¯m NmpV^ApNL ^V]]Va_ lNmVLN_pm pUN Sa]]awV_T iaiq]ApVa_m AlNconsidered especially vulnerable:
x Older Adults (65+): Approx. 1.6 million residents (15.5%)—more likely to suffer injury or health complications during wind-related power outages and evacuation events. x Access and Functional Needs (AFN) Populations: Estimated 1.7 million V_LVvVLqA]m È V_J]qLV_T pUamN wVpU LVmAIV]VpVNm ]V^VpNL ^aIV]Vpy alcommunication barriers. x Low-Income Households: Over 13% of households fall below the poverty line and may lack the resources for structural mitigation or relocation during prolonged outages.
County of Los Angeles All-Hazards Mitigation Plan
x -Nai]N xiNlVN_JV_T a^N]Nmm_Nmm - %vNl
V_LVvVLqA]m
!1 Jaq_p Ap LVlNJp lVm\ Sla^ SA]]V_T LNIlVm A_L ]AJ\ aS mUN]pNl LqlV_Twindstorms. x "aIV]Na^N0NmVLN_pmiilaxV^ApN]yq_VpmJaq_pywVLNJa_JN_plApNL in inland valleys and foothill communities that are highly exposed to Santa Ana winds. x UV]LlN_4_LNlTN
laq_L Jaq_pywVLNvq]_NlAI]N palNmiVlApaly complications from airborne particulates and debris stirred by strong winds. x Ja_a^VJ ^iAJp
qmV_Nmm LVmlqipVa_m V_JlNAmNL V_mqlA_JN J]AV^m A_L pUN Jampm aS N^NlTN_Jy lNmia_mN A_L lNJavNly ALL œ_A_JVA] IqlLN_m pa ]aJA]communities. lVpVJA]_SlAmplqJpqlNAp0Vm\Severe wind and tornado events can cause widespread cascading failures in vital mympN^mV_J]qLV_T x -awNl _SlAmplqJpqlN !am _TN]Nm aq_py Ja_pAV_m avNl ^V]Nm aS overhead power lines vulnerable to high-wV_LLA^ATNA_LœlNVT_VpVa_ x "NLVJA]AJV]VpVNm%vNl
]VJN_mNLUamiVpA]mA_LUNA]pUJ]V_VJm^A_ylN]VA_p
on uninterrupted power and access for vulnerable patient populations. x Transportation Corridors: Major highways (I-
- 41- A_L avNl
IlVLTNmiAlpVJq]Al]yV_JA_ya_A_LSaapUV]]AlNAmAlNmqmJNipVI]NpaaImplqJpVa_by fallen trees and debris. x Communication Towers: Over 800 critical telecom sites serve the county’s emergency communications and can be disrupted by high wind gusts. x 1JUaa]miilaxV^ApN]yiqI]VJ –12 schools and 100+ college campuses face operational disruptions from power outages or infrastructure damage during events.
6.10.7 Impacts 1NvNlNwV_LA_Lpal_ALaNvN_pmiamNmVT_VœJA_ppUlNApmpaJlVpVJA]V_SlAmplqJpqlNiqI]VJmASNpyA_L Ja^^q_VpyaiNlApVa_mV_!am_TN]Nmaq_pyVTUwV_LmmqJUAm pUamNLqlV_T 1A_pA _A NvN_pm lNTq]Al]y LA^ATN iawNl ]V_Nm qilaap plNNm A_L LVmAI]N County of Los Angeles
All-Hazards Mitigation Plan
plA_mialpApVa_ JallVLalm _apAI]N NxA^i]N aJJqllNL V_ A_qAly wUN_
wVLNmilNAL wV_Lmpal^m JAqmNL iawNl aqpATNm Sal ^alN pUA_ Jqmpa^NlmV_J]qLV_T AiilaxV^ApN]y !am _TN]Nm NiAlp^N_p aS :ApNl A_L -awNl!:- Jqmpa^Nlm A_L avNl 00 Southern California Edison (SCE) customers. qlV_TpUVmmA^NiNlVaLwV]LœlNmNxAJNlIApNLIypUNmpla_TwV_LmV^iAJpNLmNvNlA]^NLVJA] SAJV]VpVNm LVmlqipV_T JlVpVJA] UNA]pU mNlvVJNm A_L lNkqVlV_T pUN N^NlTN_Jyrelocation of patients.3al_ALaNmwUV]NlAlNUAvNA]maLN^a_mplApNLLNmplqJpVvNJAiAJVpyV_]aJA]V|NLAlNAm_"AlJU A_-pal_ALapaqJUNLLaw_V_-VJa0VvNlALaw_V_TiawNl]V_NmA_LplNNm A_L aImplqJpV_T laALwAym UVTU]VTUpV_T pUN iapN_pVA] Sal pal_ALVJ AJpVvVpy paimpact urban communities. These hazards not only endanger life and property but also pUlNApN_NJa_a^VJJa_pV_qVpyA_LpUNSq_JpVa_V_TaSN^NlTN_JymNlvVJNmiAlpVJq]Al]yin vulnerable neighborhoods and areas with aging infrastructure.
6.10.8 Mitigation and Preparedness Efforts to mitigate the effects of severe wind and tornadoes should focus on improving mplqJpqlA] lNmV]VN_JN N_UA_JV_T NAl]y wAl_V_Ts and alerts A_L V_JlNAmV_T iqI]VJawareness of such events. Severe Wind and Tornado Mitigation x Strengthening building codes to require wind-resistant design features.
Promoting the use of wind-resistant materials and construction techniques in new developments. x Conducting regular tree-trimming and vegetation management to reduce infrastructure damage risks.
x 0NplaœppV_TA_LlNV_SalJV_TJlVpVJA]V_SlAmplqJpqlNmqJUAmiawNl]V_NmA_LqpV]Vpy mympN^mpawVpUmpA_LUVTU-wind conditions.
x Implementing public education campaigns on windstorm preparedness and safety measures.
x Leveraging early warning alerting and ilNiAlNL_Nmm ^NmmATV_T Am wN]] Am integrating emergency messaging with local broadcast and mobile networks.
County of Los Angeles All-Hazards Mitigation Plan
6.10.9 Summary 1NvNlNwV_LA_Lpal_ALaNmpUaqTULVSSNlV_TV_SlNkqN_JylN^AV_iapN_pVA]UA|AlLmSalLos Angeles County. Santa Ana winds and storm-driven gusts regularly impact the lNTVa_JAqmV_TLA^ATNpaV_SlAmplqJpqlNA_LV_JlNAmV_TwV]LœlNlVm\m:UV]Npal_ALaNmalNlAlNpUNVlaJJAmVa_A]aJJqllN_JN_NJNmmVpApNmilNiAlNL_NmmA_L^VpVTApVa_NSSalpm y V^i]N^N_pV_T mpla_TNl IqV]LV_T JaLNm lNV_SalJV_T JlVpVJA] V_SlAmplqJpqlN A_Lenhancing preparedness and iqI]VJAwAlN_NmmpUNJaq_pyJA_lNLqJNVpmvq]_NlAIV]Vpyto these hazards helps to better protect its residents from potential hazards of severe winds and tornado and improve community resilience.
County of Los Angeles
All-Hazards Mitigation Plan
County of Los AngelesAll-Hazards Mitigation Plan6.11 Mass Violence6.11.1 Nature3UVm mNJpVa_ aqp]V_Nm pUN LNœ_V_TJUAlAJpNlVmpVJm aS ^Amm vVa]N_JNwUVJU V_J]qLNm V_pN_pVa_A] UVTUV^iAJp V_JVLN_pm mqJU Am pNllalVm^AJpVvN mUaapNl NvN_pm vNUVJ]NlA^^V_Tm A_L apUNl JaalLV_ApNLattacks. Understanding the nature of these events is critical for developing effective mitigation strategies. x Mass violence includes both
pAlTNpNL AppAJ\m NTideologically motivated terrorism) and opportunistic AJpm NT AJpVvN mUaapNlm alviolent assaults in public spaces). x 3UNmNV_JVLN_pmAlNJUAlAJpNlV|NLIypUNVl]awwAl_V_TpV^NUVTU]NpUA]VpyA_L potential to incite widespread fear and panic.
County of Los AngelesAll-Hazards Mitigation Plan
x Acts of mass violence
may be perpetrated by V_LVvVLqA]mm^A]]Tlaqimor well-organized _Npwal\m A_L JA_V_va]vN œlNAl^mNxi]amVvNm vNUVJ]Nm albiological agents. x These attacks often aim
to disrupt societal Sq_JpVa_m LA^ATNV_SlAmplqJpqlN al Nxi]aVpvulnerabilities in soft pAlTNpm mqJU Am mJUaa]mi]AJNm aS walmUVi alentertainment venues. _mq^^Aly pUN_ApqlNaS^Ammviolence lies in its deliberate V_pN_p paV_ŔVJpUAl^a_TlaqimA_L LVmlqip iqI]VJ alLNlmaking strong mitigation measures essential for protecting life and property of Los Angeles County.
6.11.2 ExtentThe potential extent of mass violence is characterized by its ability to cause widespread LVmlqipVa_A_LmVT_VœJA_p]ammaSlife and property.
County of Los Angeles
All-Hazards Mitigation Plan
x Events can result in many casualties and severe physical and psychological impacts.
x Mass violence can LVmlqip NmmN_pVA] mNlvVJNm mplAV_ N^NlTN_Jy lNmia_mN mympN^mA_LJlNApNJAmJALV_TmaJVaNJa_a^VJNSSNJpm
x 3UNavNlA]]LVmlqipVa_^AyNxpN_LSAlINya_L pUNV^^NLVApNmJN_N ASSNJpV_T broader community resilience.
_ NmmN_JN wUV]N pUNmN NvN_pm ^Ay IN lAlN pUNVl NxpN_mVvN V^iAJpm _NJNmmVpApNcomprehensive planning and resilient infrastructure.
6.11.3 History VmpalVJA]LApAV]]qmplApNmpUAp^AmmvVa]N_JNUAmNva]vNLavNlpV^NwVpUNAl]VNlNvN_pmshaping current mitigation strategies and more recent incidents underscoring emerging vulnerabilities. Previous mitigation and other plans referenced events such as large-scale terrorist attacks and active shooter incidents. x 0NJN_pNvN_pmV_pUN]AmpœvNyNAlmV_J]qLNUVTU-ilaœ]NAJpVvNmUaapNlV_JVLN_pm Ap mJUaa]m iqI]VJ plA_mialpApVa_ UqIm A_L Ja^^NlJVA] JN_pNlm Am wN]] Amvehicle-ramming attacks in urban areas. %vNlA]] pUN UVmpalVJA] plN_L mUawm pUAp wUV]NSlNkqN_Jy lN^AV_m ]aw pUN mNvNlVpy aSmass violence i_JVLN_pmUAmNmJA]ApNL_NJNmmVpApV_TJa_pV_qA]qiLApNm pa^VpVTApVa_ strategies.
6.11.4 Location "Amm vVa]N_JN V_JVLN_pm pN_L pa aJJql V_ AlNAm wUNlN iNai]N _ApqlA]]y Ja_TlNTApNV_J]qLV_T qlIA_ JN_pNlm plA_mialpApVa_ UqIm NLqJApVa_A] and religious V_mpVpqpVa_mmUaiiV_TJN_pNlmA_LiqI]VJevents and venues. x -qI]VJmiAJNmmqJUAmplA_mVpmpApVa_mmpALVq^m^A]]m and other locations where ]AlTN_q^INlaSiNai]NAmmN^I]N are considered higher-risk areas. x Critical infrastructure location like government buildings and commercial centerare often targeted.
x Certain events may also occur in areas lacking adequate physical security or surveillance.
County of Los Angeles All-Hazards Mitigation Plan
3UqmVLN_pVSyV_TA_LmNJqlV_TUVTU-density locations is a key focus for mitigating the effects of mass violence. 6.11.5 Probability 3UNilaIAIV]VpyaS^AmmvVa]N_JNV_JVLN_pmVmLVSœJq]ppailNLVJpilNJVmN]yUawNvNlpUNpotential for occurrence is recognized as a persistent low-SlNkqN_JyUVTU-impact risk that requires constant vigilance. x Such incidents are statistically rare yet present a disproportionate risk due to their catastrophic consequences.
x Threat assessments and intelligence reports indicate that evolving tactics may increase probability over time.
x a_pV_qaqm^a_VpalV_TA_LqiLApNLpUlNApA_A]ymNmNTvVA30ilaJNmmNm are essential in quantifying risk levels.
_ mq^^Aly wUV]N ^Amm vVa]N_JN NvN_pm AlN _ap Ja^^a_ pUNVl V_UNlN_punpredictability and high severity demand that communities prepare as if an incident could occur at any time. 6.11.6 Vulnerability Mass vVa]N_JNLNiN_Lma_AvAlVNpyaSSAJpalmV_J]qLV_TiUymVJA]V_SlAmplqJpqlNLNmVT_iqI]VJAwAlN_NmmmNJqlVpyilNiAlNL_NmmA_LV_pNlATN_JyJaalLV_ApVa_ x Critical vulnerabilities include open public spaces with minimal physical barriers or limited or ineffective safety / security protocols in place. x AimV_plAV_V_TA_LilNiAlNL_NmmA^a_TœlmplNmia_LNlmJA_NxAJNlIApNpUN situation during an active incident.
x Social vulnerabilities—such as communication gaps or lack of multilingual emergency information—may hinder rapid response and community resilience. 3Uqm lNLqJV_T vq]_NlAIV]Vpy V_va]vNm V_vNmpV_T V_ V_SlAmplqJpqlN UAlLN_V_T laIqmpmNJqlVpy ^NAmqlNm lNTq]Al plAV_V_T NxNlJVmNm A_L NSSNJpVvN iqI]VJ Ja^^q_VJApVa_strategies.
County of Los Angeles
All-Hazards Mitigation Plan
6.11.7 Impacts3UNV^iAJpmaS^AmmvVa]N_JNNvN_pmAlN^q]pVSAJNpNLlife safetyJa^^q_VpympAIV]Vpyand the local economy. x ^^NLVApN V^iAJpm V_J]qLN SApA]VpVNm V_[qlVNm A_L plAq^A A^a_T ASSNJpNL populations.
x 1NJa_LAly V^iAJpm ^Ay N_Ja^iAmm ila]a_TNL LVmlqipVa_ aS ]aJA] mNlvVJNm NJa_a^VJLaw_pql_mA_L]AmpV_TimyJUa]aTVJA]NSSNJpma_Ja^^q_VpVNm x Long-term consequences can involve extensive resource allocation for recovery A_L^VpVTApVa_SqlpUNlmplAV_V_TiqI]VJmympN^m
"AmmvVa]N_JNV_ŔVJpmV^^NLVApNUAl^A_LaSpN_plVTTNlmAJUAV_aSmNJa_LAlyV^iAJpmthat complicate community recovery and strain long-term resilience efforts.6.11.8 Summary_ Ja_J]qmVa_^VpVTApV_T pUNUA|AlLmaS^AmmvVa]N_JN lNkqVlNm A_V_pNTlApNL^q]pV-]AyNlNL AiilaAJU pUAp miA_m ilNvN_pVa_ ilNiAlNL_Nmm response and recovery. Communities must implement measures to secure high-lVm\ ]aJApVa_m qiTlALNiUymVJA] A_L LVTVpA] mNJqlVpy N_UA_JN V_pNlATN_Jy JaalLV_ApVa_ A_L Ja_pV_qaqm]yupdate training and threat assessments. x "VpVTApVa_mplApNTVNmV_J]qLNiUymVJA]mNJqlVpyN_UA_JN^N_pmNTIAllVNlmA_L mqlvNV]]A_JN lNTq]AlAJpVvNmUaapNlLlV]]mV^ilavNLN^NlTN_JyJa^^q_VJApVa_mympN^mA_LJaalLV_ApNL]AwN_SalJN^N_pA_LiqI]VJUNA]pUlNmia_mNm x Investment in resilience-building measures and community outreach helps to N_mqlN pUApV_ pUNNvN_paSA_V_JVLN_p Ja^^q_VpVNm JA_ lNJavNlkqVJ\]y A_Leffectively.
This section underscores that while mass violence NvN_pmAlN lAlN pUNVliapN_pVA]Salhigh impact demands rigorous preparedness and adaptive mitigation strategies to safeguard lives and maintain community functionality.
County of Los AngelesAll-Hazards Mitigation Plan
6.12 Cybersecurity Incidents
6.12.1 Nature
Cybersecurity incidents refer to disruptive events affecting digital networks and systems. These events involve the unauthorized electronic or physical access of information systems that jeopardizes or disrupts pUN V_pNTlVpy Ja_œLN_pVA]Vpy alavailability of information. Cyber incidents can range from minor targeted data breaches to largescale ransomware attacks and distributed denial-of-service (DDoS) events that compromise critical infrastructure. Common types of JyINlmNJqlVpy V_JVLN_pm V_J]qLN Iqpare not limited to:
x Data Breaches: 3UN Ja^ila^VmN q_AqpUalV|NL LVmJ]amqlN al q_AqpUalV|NL acquisition of information.
County of LosA ngelesAll-Hazards Mitigation Plan
County of Los Angeles
All-Hazards Mitigation Plan
x Malware: "A]VJVaqm UAlLwAlN œl^wAlN al maSpwAlN pUAp Vm V_pN_pVa_A]]y included or inserted in a system for a harmful purpose. x 0A_ma^wAlN A type of malicious software designed to lock access to a system until a ransom payment is received. Note that ransom payment is not a guarantee that system access will be restored by the threat actor. x Denial of Service (DoS): _AppAJ\^NA_ppamUqpLaw_A^AJUV_Nal_Npwal\ rendering it inaccessible to its intended users.
x Distributed Denial of Service (DDos): A DoS attack that uses numerous hosts to perform the attack.
x Insider Threats: :UN_ A_ V_mVLNl NT A_ N^i]ayNN al vN_Lal qmNm pUNVl AqpUalV|NLAJJNmmwVppV_T]yalq_wVppV_T]ypaLaUAl^paA_alTA_V|ApVa_ x -UVmUV_TppAJ\m The fraudulent practice of sending emails purporting to be from reputable senders in order to induce individuals to reveal information or download malware by clicking on a link.
Key characteristics of a cybersecurity incident include: 0AiVL%_mNp Impacts to operations can occur suddenly and evolve quickly. x Sophistication: Can be highly sophisticated with state or non-state actors involved.
x yIlVL ppAJ\m May involve both cyber and physical components due to interdependencies.
x Non-Malicious Incidents: Technological failures that cause similar impacts to cybersecurity incidents may also occur due to non-malicious reasons such as a software or hardware issue.
Understanding the inherent digital nature and complex characteristics of these incidents is critical to developing effective prevention and mitigation strategies.
6.12.2 Location 4_]V\N plALVpVa_A] UA|AlLm pUAp UAvN A iUymVJA] TNaTlAiUVJ SaapilV_p JyINlmNJqlVpyV_JVLN_pmAlNV_UNlN_p]yplA_mIaq_LAlyawNvNlpUNVlNSSNJpm^A_VSNmp]aJA]]ypUlaqTUthe disruption of critical services and systems and necessitate regionally coordinated preparedness and response efforts.
County of Los Angeles All-Hazards Mitigation Plan
qlVmLVJpVa_A]0N]NvA_JN
x Impact local government networks and county infrastructure. x Affect public and private sector systems within Los Angeles County. x Disrupt critical infrastructure such as utilities and cause cascading impacts. x _va]vN JyINl _aLNm pUAp wUV]N T]aIA]]y LVmplVIqpNL Ja_vNlTN a_ lNTVa_A] networks.
Critical Sectors Impacted:
x Hospitals and healthcare facilities. x FinancialIA_\V_TaliAyla]]systems. x Transportation providers and systems. x 4pV]VpVNmmqJUAmN]NJplVJVpyTAmA_LwApNlx Emergency response and public safety agencies.
6.12.3 Extent The extent of cybersecurity incidents is measured not only by the volume of Ja^ila^VmNL LApA al œ_A_JVA] ]amm Iqp A]ma Iy pUN iapN_pVA] LVmlqipVa_ pa NmmN_pVA]services and critical infrastructure. Scope of Impacts:
x Rapid spread across interconnected digital systems. x Potential for cascading failures that disrupt multiple sectors. x Economic losses that may run into millions of dollars.
Measurable Factors:
x Number of systems compromised. x Downtime of critical infrastructure and services. x Financial costs from remediation and lost productivity.
The extensive reach of cybersecurity incidents—both in terms of economic impact and service disruption—highlights the need for robust digital defenses Ja_pV_qVpy aSaiNlApVa_mi]A__V_TIAJ\qimympN^mA_LlNLq_LA_JVNmLVmAmpNllNJavNlymplApNTVNmand regional cyber response coordination.
County of Los Angeles
All-Hazards Mitigation Plan
6.12.4 History VmpalVJA]]y JyINlmNJqlVpy V_JVLN_pm UAvN Nva]vNL Sla^ Vma]ApNL IlNAJUNm pacoordinated attacks that leverage global networks. Early cybersecurity incidents focused on data theft and vandalism. More recent attacks have grown increasingly sophisticated and targeted critical infrastructure or use complex ransomware. Cyber threat actors include state-sponsored groups along with non-state groups such as criminal enterprises and terrorist organizations. Recent years have seen cybersecurity incidents affecting ]AlTNJalialApVa_miqI]VJN_pVpVNmV_J]qLV_T]aJA]TavNl_^N_pmA_Lcritical infrastructure sectors. Previous major cybersecurity incidents have included:
x !am_TN]Nmaq_py1qiNlValaqlp0A_ma^wAlNppAJ\Resulted in pUNmUqpLaw_aS_NAl]yNvNlyJaqlpmympN^A^q]pV-LAyJ]amqlNaSpUNJaqlpA_Lcascading impacts to operations. x amiVpA]laqippAJ\A major hospital company experienced an attack that caused IT and phone system outages and disrupted patient care at several Los Angeles County hospitals. x 3N]NJa^^q_VJApVa_ _Lqmply ppAJ\m: A series of attacks against telecommunications providers in the United States resulted in compromised customer data. x VpyppAJ\A cybersecurity incident at a city within Los Angeles County JAqmNLJVpy3mympN^mpaINpA\N_aSŔV_N
x vVApVa__LqmplyppAJ\m A series of cybersecurity incidents targeting the airports and airlines caused transportation system disruptions.
The historical progression from rudimentary attacks to highly coordinated cybersecurity incidents underscores the growing importance of proactive risk management in the digital realm.
6.12.5 Probability The probability of cybersecurity incidents occurring is increasing as digital interconnectivity expands and as attackers continue to innovate their methods.
County of Los Angeles All-Hazards Mitigation Plan
0Vm\Trends:
x Rapid expansion of the Internet of Things (IoT) pUN _Npwal\ aS V_pNl_Npconnected devices ranging from smart refrigerators to autonomous vNUVJ]Nm has added new attack vectors to the threat landscape.
x Increasing sophistication of cybercriminal methods including zero-LAyNxi]aVpm a previously unknown cybersecurity vulnerability.
x Growing frequency of reported incidents nationally and globally.
Contributing Factors:
x Inadequate cybersecurity measures in legacy systems still being used by organizations.
x Underinvestment in cyber defense infrastructure or cybersecurity expertise. x Greater digital reliance in everyday operations without proper continuity of operations planning.
VvN_JqllN_pplN_LmA_LpNJU_a]aTVJA]LNvN]ai^N_pmpUN]V\N]VUaaLaSJyINlmNJqlVpyV_JVLN_pmlN^AV_mUVTU_NJNmmVpApV_Ta_TaV_TvVTV]A_JNA_LN_UA_JNLilNiAlNL_Nmmmeasures. mJyINlmNJqlVpyV_JVLN_pmJa_pV_qNpaV_JlNAmNV_SlNkqN_JypUNiapN_pVA]for an incident to cause cascading and widespread impacts to critical infrastructure increases as well.
6.12.6 Vulnerability Vulnerability in the context of cybersecurity refers to the susceptibility of digital systems paAppAJ\3UVmVmV_ŔqN_JNLIyIapUpNJU_a]aTVJA]A_LalTA_V|ApVa_A]SAJpalmV_J]qLV_TIqp _ap ]V^VpNL pa aqpLApNL maSpwAlN al qmN aS ]NTAJy mympN^m V_mqSœJVN_p iApJU^A_ATN^N_pV_ALNkqApNmNT^N_pApVa_A_LLNSN_mN-in-LNipUmplApNTVNmA_L]AJ\aScybersecurity training among personnel. Organizational challenges also contribute to JyINlmNJqlVpy vq]_NlAIV]Vpy V_J]qLV_T Iqp _ap ]V^VpNL pa IqLTNp Ja_mplAV_pmgaps in JaalLV_ApVa_ A_L lAiVL pNJU_a]aTy ALaipVa_ wVpUaqp JallNmia_LV_T mNJqlVpyprotocols. JJalLV_TpapUN3UlNApA_LA|AlLLN_pVœJApVa_A_L0Vm\mmNmm^N_p30 avNl iNai]N ^Ay IN ASSNJpNL Iy A ]AlTN-scale cybersecurity incident with cascading impacts to utilities. Over of those impacted in the THIRA scenario are estimated to UAvN AJJNmm A_L Sq_JpVa_A] _NNLm A_L avNl iNai]N are County of Los Angeles
All-Hazards Mitigation Plan
estimated to have ]V^VpNL_T]VmUilaœJVN_JyNiN_LV_Ta_ pUNqpV]VpVNmASSNJpNLIythe V_JVLN_pAwVLNmilNALA^aq_paS pUNiaiq]ApVa_Jaq]LINwVpUaqpqpV]VpymNlvVJNfor an extended period. Addressing these vulnerabilities is essential to reduce the risk and potential disruption aSJyINlmNJqlVpyV_JVLN_pmJA]]V_TSalIapUpNJU_VJA]qiTlALNmand improved interagency coordination. 6.12.7 Impacts 3UNV^iAJpmaSJyINlmNJqlVpyV_JVLN_pmAlN^q]pVSAJNpNLASSNJpV_TNJa_a^VJmpAIV]VpyiqI]VJmASNpyA_LJlVpVJA]V_SlAmplqJpqlNaiNlApVa_mDirect Impacts:
x VmlqipVa_ aS JlVpVJA] mNlvVJNm NT UNA]pUJAlN N^NlTN_Jy lNmia_mN plA_mialpApVa_NpJ).
x Extended duration Continuity of Government or Continuity of Operations event. x Financial losses due to ransom payments remediation costsA_LiapN_pVA]]NTA] fees.
x Losscompromisealq_AqpUalV|NLlN]NAmN of sensitive data.
Indirect impacts:
x Erosion of public trust in digital services and affected institutions. x AmJALV_T NSSNJpm a_ iUymVJA] V_SlAmplqJpqlN NT iawNl TlVL wApNl mympN^m wAmpNwApNlNpJ
x Long-term economic repercussions from reduced competitiveness. x 3UN mVT_VœJA_p V^iAJpm—both direct and cascading—of cybersecurity incidents necessitate comprehensive mitigation and recovery strategies that address both technical and socioeconomic dimensions.
6.12.8 Summary _ mq^^Aly JyINlmNJqlVpy V_JVLN_pm lNilNmN_p A_ Nva]vV_T A_L JlVpVJA] pUlNAp pUApintersects with multiple aspects of community resilience and safety. Ny3A\NAwAym x yINlV_JVLN_pmAlNLy_A^VJmaiUVmpVJApNLA_LSAl-reaching in impact x They affect local systems despite their global nature County of Los Angeles All-Hazards Mitigation Plan
x Historical trends and increasing digital dependency heighten both probability and vulnerability
x ^iAJpmNxpN_LINya_Lœ_A_JVA]]ammpaV_J]qLNmNlvVJNLVmlqipVa_A_L cascading infrastructure failures
yINlmNJqlVpy V_JVLN_pm LN^A_L A ilaAJpVvN JaalLV_ApNL lNmia_mN pUAp V_pNTlApNmrobust technical defenses with cross-sector planning and recovery efforts. By q_LNlmpA_LV_T pUN _ApqlN mJaiN A_L iapN_pVA] Ja_mNkqN_JNm aS pUNmN V_JVLN_pmcommunities can build more resilient digital and physical infrastructures to safeguard against this growing threat.
County of Los Angeles
All-Hazards Mitigation Plan
6.13 Transportation Incidents6.13.1 NatureThis section describes the inherent characteristics of transportation incidents that can LVmlqip pUN Ja_pV_qaqm Ŕaw aS iNai]N TaaLm A_L N^NlTN_Jy mNlvVJNm AJlamm !amAngeles County. Transportation incidents can be triggered by a variety of factorsV_J]qLV_T _ApqlA] NvN_pm Uq^A_ Nllal A_L LN]VINlApN AJpm Other characteristics include:
x Affected Modes of Transportation: Incidents can involve any mode of transportation such as multi-vNUVJ]N Ja]]VmVa_m UA|AlLaqm ^ApNlVA] miV]]m lAV]LNlAV]^N_pmAvVApVa_incidentsA_L^AlVpV^NLVmlqipVa_m x Cascading Impacts: Disruptions to the transportation system often have the potential to trigger cascading failures due to the interconnected design of UVTUwAymlAV]_Npwal\mAVlialpmA_Lseaports. x Contributing Factors: Incidents may INV_ŔqN_JNLIyIapUilNLVJpAI]NSAJpalm NT rush-Uaql Ja_TNmpVa_ A_L q_ilNLVJpAI]N aJJqllN_JNm NT NxplN^Nweather or infrastructure failure).
6.13.2 Location3UNJaq_py¯m_Npwal\N_Ja^iAmmNmUVTUwAymlAV]AVlialpmialpmA_L]aJA]laALmpUApCouare critical to regional mobility and commerce. nty of Los Angeles
All-Hazards Mitigation Plan
County of Los AngelesAll-Hazards Mitigation Plan
x Freeways: Los Angeles County boasts an extensive freeway system with over ^V]NmaS UVTU-capacity roads including corridors such as I- -
-I-A_L-210.
x Major Transportation Hubs: The County is home to three commercial airports including Los Angeles International Airport (LAX) Long Beach Municipal Airport(LGB) and the Hollywood Burbank Airport (BUR) along with several general AvVApVa_ AVlialpm 3UN aq_py aw_m A_L aiNlApNm lAJ\Npp VN]L Vlialpa^ipa_:aaL]NyVlialp 1A_AIlVN]9A]]NyVlialpN_NlA]:V]]VA^ ax VlœN]LA_L:UVpN^A_Vlialp The -alpmaS!am_TN]NmA_L!a_T NAJUwUVJUare two of the busiest ports in the United States and vital for national and international trade AlN A]ma V_ !am_TN]Nm aq_pyLLVpVa_A]]y !am_TN]NmUnion Station serves as the largest passenger rail station on the west coast. x %pUNl 3lA_mialpApVa_ #Npwal\m The county includes robust passenger rail busA_LiAlAplA_mVp mympN^mA]a_TwVpUSlNVTUplAV]mympN^memerging mobility options such as taxis and rideshare services and enhanced bicycle networks. 3UVm Ja^ilNUN_mVvN _Npwal\ Vm pUN IAJ\Ia_N Sal LAV]y Ja^^qpV_T SlNVTUp^avN^N_pA_LN^NlTN_JylNmia_mNAJlammpUNlNTVa_
6.13.3 ExtentThe scope of transportation incidents spans multiple modes of travel and can have widespread consequences across the county’s integrated infrastructure. Road incidents may include multi-vNUVJ]N Ja]]VmVa_m UA|AlLaqm ^ApNlVA] miV]]m A_L laALwAy œlNmimpacting multiple vehicles with potential delays in emergency responses. x 0AV]LVmlqipVa_mJA_V^iNLNJa^^qpNlA_LSlNVTUpmNlvVJNmV^iAJpV_TIapU]aJA] transit and regional connectivity.
x Air and maritime incidents—such as delays at major airports or disruptions at port facilities—JA_mVT_VœJA_p]yASSNJpJa^^NlJNmqii]yJUAV_mA_LiqI]VJmASNpy x Cascading effects across interconnected transportation modes may exacerbate Ja_TNmpVa_ A_L mplAV_ ALLVpVa_A] V_SlAmplqJpqlN mympN^m mqJU Am iawNl wApNland emergency communications.
The extensive and interdependent nature of these networks means that an incident in a_NAlNAJA_kqVJ\]yV_ŔqN_JN^q]pVi]NplA_mialpApVa_mympN^m County of Los Angeles
All-Hazards Mitigation Plan
6.13.4 History Los Angeles County has a long record of transportation-related incidents that have disrupted mobility and commerce. x 9V_JN_p3Ua^Am
lVLTNVlN A semi-truck carrying lithium-ion batteries avNlpql_NLA_LJAqTUpœlNJAqmV_TpUNIlVLTNpaINJ]amNLSalmNvNlA]LAym x 2023 I-10 Freeway Fire: œlN V_ A iA]]Np yAlL IN]aw pUN -10 freeway in Downtown Los Angeles caused an eight-day closure for repairs and major cascading disruptions. x 2020 Delta Air Lines Flight 89 Fuel Drop: 1Ualp]y ASpNl pA\NaSSSla^ !; A Boeing 777 encountered engine problems and conducted a fuel dump over iaiq]ApNLAlNAmV_[qlV_TavNl iNai]Na_pUNTlaq_L
x UApmwalpU"Npla]V_\NlAV]^N_p A Metrolink passenger train collided wVpUA4_Va_-AJVœJSlNVTUpplAV_V_[qlV_TavNliNai]NA_LJAqmV_T LNApUm
x 2007 Newhall Pass Tunnel Fire: A multi-vehicle collision involving over 30 vNUVJ]NmJAqmNLAœlNwVpUV_pUNpq__N]V_[qlV_TiNai]NA_LJAqmV_TLNApUm The historical record reinforces the need to learn from previous events to enhance future preparedness and resilience. 6.13.5 Probability The likelihood of transportation incidents in Los Angeles County remains elevated due to several converging factors V_J]qLV_TIqp_ap]V^VpNLpa x VTULAV]y plASœJva]q^Nma_SlNNwAym A_L AlpNlVA]mV_JlNAmN pUN lVm\aS^q]pVvehicle accidents and congestion-related incidents. x Aging infrastructure—V_J]qLV_TIlVLTNmlaALmqlSAJNmA_LlAV]mympN^m—creates AiNlmVmpN_p lVm\aSSAV]qlNiAlpVJq]Al]y q_LNl NxplN^NwNApUNl Ja_LVpVa_m A_Lduring peak usage periods. x 3UNJaq_py¯mla]NAmA^A[alUqISalSlNVTUpA_LJa^^qpNlplASœJ^NA_mpUApNvN_ minor incidents can escalate rapidly into larger disruptions. x The frequent movement of hazardous materials and the increasing reliance on just-in-time delivery systems further elevate the risk of incidents with potentially severe consequences.
County of Los Angeles All-Hazards Mitigation Plan
3aTNpUNl pUNmNSAJpalmJa_plVIqpN paAJa_mVmpN_p]yUVTUilaIAIV]VpyaSplA_mialpApVa_incidents impacting the region. 6.13.6 Vulnerability The vulnerability of Los Angeles County’s transportation system is compounded by its interdependent design and its critical role in the regional economy. x Limited redundancy in key corridors means that a disruption on one freeway or rail line can quickly overload alternate routes.
x TV_T A_L avNlIqlLN_NL V_SlAmplqJpqlN Vm ]Nmm lNmV]VN_p pa NxplN^N NvN_pm leading to longer recovery times after incidents.
x The county’s economic dependence on uninterrupted transportation for daily Ja^^qpV_T A_L Ja^^NlJVA] SlNVTUp V_JlNAmNm NxiamqlN pa mVT_VœJA_p ]ammNmduring disruptions. x a^i]Nx V_pNlLNiN_LN_JVNm INpwNN_ plA_mialpApVa_ mympN^m N^NlTN_Jy mNlvVJNm A_L apUNl JlVpVJA] mNJpalm ^A\N pUN _Npwal\ UVTU]y mN_mVpVvN pacascading failures. 3UVm mympN^VJ vq]_NlAIV]Vpy JA]]m Sal JaalLV_ApNL ^q]pV-agency efforts to bolster resilience and implement proactive mitigation measures. 6.13.7 Impacts Transportation incidents can produce both immediate and long-lasting effects on iqI]VJmASNpyJa^^NlJNA_LavNlA]]kqA]VpyaS]VSN
1. 3lASœJ A_L "aIV]Vpy Disruptions can lead to severe congestion affecting Uq_LlNLmaSpUaqmA_LmaSJa^^qpNlmA_LSlNVTUpvNUVJ]NmLN]AyV_TN^NlTN_Jy services and disrupting daily operations.
2. Economic Loss: Interruptions in the movement of goods and people can result V_ mqImpA_pVA] œ_A_JVA] ]ammNm V^iAJpV_T ]aJA] IqmV_NmmNm A_L pUN IlaALNl regional economy.
3. Public Safety: Extended delays in emergency response and Emergency Medical Services (EMS) transport times.
4. Cascading Disruptions: _ V_JVLN_p V_ a_N ^aLN NT A ^A[al UVTUwAy J]amqlN JA_ lVii]N pUlaqTU pUN plA_mialpApVa_ _Npwal\ ASSNJpV_T lAV] AVl A_Lmaritime operations simultaneously and complicating recovery efforts.
These impacts highlight the critical need for robust mitigation strategies to manage both direct and indirect consequences of transportation incidents.
County of Los Angeles
All-Hazards Mitigation Plan
6.13.8 SummaryLos Angeles County’s transportation network is among the most extensive and complex V_ pUN _ApVa_ mNlvV_T ^V]]Va_m aS lNmVLN_pm A_L q_LNliV__V_T A vVpA] NJa_a^VJNJamympN^ 3UN LVvNlmN plA_mialpApVa_ ^aLNm wUV]N SAJV]VpApV_T ^aIV]Vpy A_LJa^^NlJNA]maJlNApNvq]_NlAIV]VpVNmLqNpaavNl]AiiV_TV_SlAmplqJpqlNA_LUVTUplASœJvolumes. x TV_T V_SlAmplqJpqlN Jaqi]NL wVpU pUN Ja_pV_qaqm ^avN^N_p aS UA|AlLaqm ^ApNlVA]m A_L pUN V_JlNAmV_T ilNmmqlNm aS LAV]y qmATN Ja_plVIqpNm pa A UVTU probability of incidents.
x Historical data demonstrate that even localized incidents can have far-reaching V^iAJpm V_J]qLV_T ila]a_TNL plASœJ Ja_TNmpVa_ NJa_a^VJ LVmlqipVa_m A_Lpublic safety challenges. _Ja_J]qmVa_^VpVTApV_TplA_mialpApVa_V_JVLN_plVm\mV_!am_TN]Nmaq_pylNkqVlNmA_V_pNTlApNLJaq_pywVLNAiilaAJUpUApJa^IV_NmV_SlAmplqJpqlNqiTlALNmN_UA_JNLN^NlTN_Jy lNmia_mN A_L ilaAJpVvN ^AV_pN_A_JN mplApNTVNm LLlNmmV_T pUNmNchallenges Vm NmmN_pVA] pa mASNTqAlL iqI]VJ mASNpy N_mqlN NJa_a^VJ mpAIV]Vpy A_Lmaintain the region’s critical mobility infrastructure.
County of Los AngelesAll-Hazards Mitigation Plan
6.14 Public Health Emergencies6.14.1 NaturePublic health emergencies in Los Angeles County encompass a broad miNJplq^ aS iapN_pVA] UA|AlLmincluding infectious disease aqpIlNA\m N_vVla_^N_pA] UNA]pUUA|AlLm A_L UN^VJA] Va]aTVJA]0ALVa]aTVJA] #qJ]NAl xi]amVvNm(CBRNE) hazards. Given the county's LVvNlmN iaiq]ApVa_ qlIA_ LN_mVpyA_L NJa_a^VJ mVT_VœJA_JN iqI]VJhealth hazards require a coordinated response among government ATN_JVNmUNA]pUJAlNV_mpVpqpVa_mA_Lcommunity partners.Public health emergencies refer to V_JVLN_pm pUAp iamN A mVT_VœJA_pthreat to the health of a population. These includeIqpAlN_ap]V^VpNLpa:
x -A_LN^VJmNT%9-_ŔqN_|A x
VapNllalVm^NT_pUlAx1^A]]iaxIapq]Vm^)
County of LosAngelesAll-Hazards Mitigation Plan
County of Los Angeles
All-Hazards Mitigation Plan
x Vector-Ial_NLVmNAmNmNT:Nmp#V]N9Vlqm?V\A x Foodborne and waterborne illnesses x Chemical and radiological exposure x Climate-lN]ApNLUNA]pUpUlNApmNTNxplN^NUNApiaalAVlkqA]VpywV]LœlNm The County of Los Angeles Department of Public Health (DPH) and the Emergency "NLVJA]1NlvVJNmTN_Jy"1 Ja]]AIalApNpa^a_VpalpUlNApmilNvN_paqpIlNA\mA_Lmitigate impacts when emergencies arise.
6.14.2 Location and Extent Los Angeles CountyUa^NpaavNl9.7 ^V]]Va_lNmVLN_pmVmpUN^ampiaiq]aqmJaq_py in the United States. Its diverse geography VNqlIA_JaAmpA]^aq_pAV_aqmA_LlqlA]) and demography lead to a range of public health vulnerabilities. -qI]VJ UNA]pU N^NlTN_JVNm JA_ alVTV_ApN Sla^ ]aJA] lNTVa_A] _ApVa_A] al T]aIA]maqlJNmV^iAJpV_TmiNJVœJ_NVTUIalUaaLmalpUNN_pVlNJaq_py3UNNxpN_paSiqI]VJhealth threats varies based on:
x 3UN_ApqlNaSpUNpUlNApmqJUAmplA_m^VmmVa_Ly_A^VJmalAvAV]AIV]VpyaS^NLVJA] countermeasures.
x Population density (higher risks in urban centers for communicable diseases) x Access to healthcare infrastructure x _vVla_^N_pA]Ja_LVpVa_mAVlia]]qpVa_NxplN^NUNApNvN_pm
6.14.3 History Public health emergencies in Los Angeles County have included:
x 2022 Monkeypox Outbreak
o iilaxV^ApN]y
JAmNmwNlNlNialpNLV_!am_TN]Nmaq_py
x COVID-19 Pandemic (2020–Present)
o %vNl ^V]]Va_ JAmNm
UamiVpA]V|ApVa_m A_L
LNApUm
reported in the county alone.
x 2018 Hepatitis A Outbreak
o -lV^AlV]y ASSNJpV_T q_UaqmNL iaiq]ApVa_m lNkqVlV_T ^Amm vAJJV_ApVa_ efforts.
x 2016-2017 West Nile Virus Outbreaks
o Multiple cases of mosquito-borne infections leading to severe illness and fatalities.
County of Los Angeles All-Hazards Mitigation Plan
x 2015-2016 Zika Virus Outbreak
o No cases of local mosquito-Ial_NplA_m^VmmVa_IqppUNlNwNlNJAmNm lNialpNLV_pUNaq_pywVpUINV_TplAvN]-related.
x 2015 Meningococcal Disease Cluster
o An outbreak among men who have sex with men (MSM) led to a targeted vaccination campaign.
x #_ŔqN_|A-A_LN^VJ
o 3UaqmA_LmaSUamiVpA]V|ApVa_mmJUaa]mA_LIqmV_NmmNmASSNJpNL
6.14.4 Probability and Emerging Risks 3UN3UlNApA_LA|AlLLN_pVœJApVa_A_L0Vm\mmNmm^N_p30 VLN_pVœNm that pandemics and bioterrorism remain high-probability threats. Future public health risks also include:
x Emergence of infectious diseases driven by global travel and climate change. x Increased incidence of heat-related illnesses amid rising temperatures. x Increased prevalence of respiratory diseases due to declining air quality. x Rise of antimicrobial-resistant infections due to overuse of antibiotics.
The County of Los Angeles DPH continually assesses health threats and updates preparedness plans to address evolving concerns. 6.14.5 Vulnerability and Systemic Impacts Certain populations in Los Angeles County may be disproportionately affected by public health emergencies:
x At-lVm\ iaiq]ApVa_m^Ay IN LVSSNlN_pSal LVSSNlN_p UA|AlLm INSalN LqlV_T A_L after an emergency. It is important to assess each hazard in turn to identify those who may be disproportionately affected to improve preparedness and response efforts. -qI]VJUNA]pUN^NlTN_JVNmmplAV_pUNUNA]pUJAlNmympN^LVmlqipNJa_a^VJAJpVvVpyA_Lcreate mental health burdens. The 2024 THIRA report noted that:
x Healthcare infrastructure overload is a major concern during pandemics. x Potential economic loss from business closures during a prolonged public health crisis could exceed billions of dollars.
County of Los Angeles
All-Hazards Mitigation Plan
6.14.6 Mitigation Strategies and Preparedness Efforts Los Angeles County employs several mitigation and preparedness strategies:
x Mass Vaccination Campaigns
o __qA] Ŕq mUapm %9- vAJJV_ApVa_m A_L aqpIlNA\-miNJVœJ immunization efforts.
x Points-of-Dispensing (POD) sites
o Disease Surveillance & Early Warning Systems
x Syndromic surveillance for emerging threats.
o Targeted sampling surveillance.
x Healthcare Infrastructure Strengthening
o Expanding hospital capacity Sal^NLVJA]mqlTN and emergency medical resources.
x Community Outreach & Public Health Education
o Disseminating critical information in multiple languages. x Emergency Stockpiles (Strategic National Stockpile(SNS)) o Ni]ay^N_paSA_pVIVapVJmA_pVvVlA]mA_LiNlma_A]ilapNJpVvNNkqVi^N_p (PPE) in crisis situations.
x Coordination with Federal & State Agencies
o Collaboration wVpU"A_LpUNA]VSal_VANiAlp^N_paS-qI]VJ Health to enhance response capabilities.
x Anthrax Threat Simulations
o The County of Los Angeles Metro system assessed as a high-risk area for bioterrorism response.
6.14.7 Summary -qI]VJ UNA]pU N^NlTN_JVNm iamN mVT_VœJA_p JUA]]N_TNm pa Los Angeles County V^iAJpV_TUNA]pUJAlNmympN^mvq]_NlAI]Niaiq]ApVa_mA_LNJa_a^VJmpAIV]Vpy:UV]Nthe COVID- iA_LN^VJ ilavVLNL A^A[al mplNmm pNmpSal lNmia_mN NSSalpma_TaV_TilNiAlNL_Nmm mqlvNV]]A_JN A_L ^VpVTApVa_ mplApNTVNm AV^ pa ilapNJp lNmVLN_pm Sla^ future threats. Ny3A\NAwAym
x Los Angeles County SAJNm LVvNlmN UNA]pU pUlNApm V_J]qLV_T iA_LN^VJm IVapNllalVm^A_LJ]V^ApN-related illnesses.
County of Los Angeles All-Hazards Mitigation Plan
x Vulnerable populations may suffer disproportionate impacts during public health crises.
x -lNiAlNL_Nmm NSSalpmSaJqm a_ mqlvNV]]A_JN vAJJV_ApVa_ N^NlTN_Jy lNmia_mN and coordination with federal and state partners.
x qpqlNpUlNApmV_J]qLNN^NlTV_TV_SNJpVaqmLVmNAmNmUNAp-lN]ApNLV]]_NmmNmA_L antimicrobial resistance.
yJa_pV_qV_TV_vNmp^N_pmV_iqI]VJUNA]pUilNiAlNL_NmmLos Angeles County aims to reduce risks and strengthen resilience against future health emergencies.
County of Los Angeles
All-Hazards Mitigation Plan
7 Mitigation Strategy
County of Los Angeles All-Hazards Mitigation Plan
7.1 Mitigation Strategy Overview The Mitigation Strategy section of the All-Hazard Mitigation Plan (AHMP) presents Los Angeles County’s strategic blueprint for reducing risks and vulnerabilities posed over pUN]a_T pNl^AmmaJVApNLwVpU pUNUA|AlLmVLN_pVœNLV_ pUNA|AlLLN_pVœJApVa_And 0Vm\ mmNmm^N_p mNJpVa_ 3UN mplApNTVNm VLN_pVœNL V_ pUVm mNJpVa_ LlVvN ^VpVTApVa_activities based on existing capabilities while also identifying areas of potential future V_vNmp^N_p pa IqV]L lNmV]VN_JN AJlamm Ja^^q_VpVNm JlVpVJA] SAJV]VpVNm A_L apher infrastructure within Los Angeles County.
7.2 Mitigation Goals and Objectives Mitigation goals are the long-term vision that the County hopes to achieve by V^i]N^N_pV_TpUNvAlVaqm^VpVTApVa_mplApNTVNmLNmJlVINLV_pUVm"-AmwN]]AmpUNbroad guidelines that have shaped mitigation strategy development. x aA] Protect life, property, infrastructure, the environment, and the economy pUlaqTUNkqVpAI]N^VpVTApVa_mplApNTVNmAV^NLAplNLqJV_TlVm\mof natural and human-caused hazards. o Objective 1- _pNTlApN vq]_NlAI]N iaiq]ApVa_m V_J]qLV_T iNai]N wVpU JJNmm A_L q_JpVa_A] #NNLm # V_pa pUN V^i]N^N_pApVa_ aS A_ypotential mitigation actions. o Objective 1-2: Implement mitigation strategies that enhance resilience to LVmAmpNlV^iAJpmAJlammlNmVLN_pVA]AlNAmJa^^NlJVA]AlNAmV_SlAmplqJpqlNhigh-UA|AlLiapN_pVA]LA^mA_LapUNlJlVpVJA]SAJV]VpVNm o Objective 1- _Sal^ mplApNTVJ V_vNmp^N_pm V_ J]V^ApN ALAipApVa_ LNvN]ai^N_p A_L lNLNvN]ai^N_p pUAp AlN JN_pNlNL V_ NkqVpy A_Lresilience. x aA]_UA_JNJa^^q_Vpy-wide partnerships in hazard mitigation across all levels of government, the private sector, and the public. o Objective 2-1: Build a culture of disaster resilience and awareness of local UA|AlLmpUlaqTUiqI]VJN_TATN^N_pNLqJApVa_A_LaqplNAJU o Objective 2-2: Strengthen direct coordination among Los Angeles County Operational Area partners to unify efforts for mitigation activities. o Objective 2-3: Utilize a whole community approach to address disparities V_aqpJa^NmiamNLIypUNUA|AlLmVLN_pVœNLV_pUVm"- x aA] Enhance planning, response, and recovery through hazard VLN_pVœJApVa_AmmNmm^N_p^VpVTApVa_A_LlNmV]VN_JNAJpVvVpVNm County of Los Angeles
All-Hazards Mitigation Plan
o Objective 3-1: Establish and maintain coordination between hazard mitigation activities and other emergency management functions. o Objective 3-2: Integrate hazard mitigation activities into preparedness for future large-scale planned events within Los Angeles County. x aA] _mqlN N]VTVIV]Vpy Sal "TlA_p Sq_LV_T pa^AxV^V|N NkqVpAI]N investment in hazard mitigation actions.
o Objective 4-1: Continue to meet all requirements for existing hazard mitigation grant programs used by the County.
o Objective 4-2: Expand the County’s ability to participate in grant programs not currently utilized by the County.
7.2.1 Changes in Mitigation Goals The AHMP Advisory Committee reviewed the 2020 AHMP goals and updated them to lNŔNJppUN^ampJqllN_pCaq_pyJa_JNl_mA_LilValVpVNm3UNlNSalNpUN "-has
introduced new goals and objectives to build a more resilient community. Table 7-1 IN]aw Ja^iAlNm pUN "- TaA]m wVpU ilNvVaqm "- TaA]m A]] apUNlgoals above are new goals and objectives developed by the AHMP Advisory Committee. Mitigation priorities change through time depending on the type of disaster impacting !am_TN]Nmaq_pyvq]_NlAIV]VpypUNmplApNTVNmV^i]N^N_pNLAmwN]]AmapUNl_NNLmof the community. Priorities are also made based on current countywide Threat and Ha|AlL LN_pVœJApVa_ A_L 0Vm\ mmNmm^N_p 30 mpqLVNm #ApVa_A] 0Vm\ _LNxmmNmm^N_p1pApNA|AlL"VpVTApVa_-]A_1"- A_L other local plans and guides. The previous 2020 AHMP integrated hazard data into several operational plans including but not li^VpNL pa pUN N_NlA] -]A_ %iNlApVa_A] lNA ^NlTN_Jy %iNlApVa_m -]A_ %%- amongst others. Addressing these changes will help to address Los Angeles County hazard priorities and to have mitigation strategies focused on the hazards that impact the region at most. The plan also added additional hazards and addressed a larger vulnerable population.
Table 7-"VpVTApVa_aA]4iLApNm
aA]mLLlNmmNLV_
2020 AHMP
aA]mSal
-2030
Planning Period
Changes
Build a culture and practice disaster resilience
Goal 2 (see above). aA]NxiA_LNL
previous goal integrated as an
County of Los Angeles All-Hazards Mitigation Plan
aA]mLLlNmmNLV_
2020 AHMP
aA]mSal
-2030
Planning Period
Changes
objective under Goal 2 in the current AHMP.
NppNli]A_SallNmia_LpaA_LlNJavNlSla^hazards and disasters V_J]qLV_TJ]V^ApNJUA_TNLlaqTUpNAlpUkqA\NLA^SAV]qlNŔaaL]A_Lm]VLNpmq_A^VA_LwV]LœlNpUApASSNJp!amAngeles County.
Goal 3 (see above). Previous goal replaced
with new goal.
More successfully adapt to hazards and disasters V_J]qLV_TJ]V^ApNJUA_TNLlaqTUpNAlpUkqA\NLA^SAV]qlNŔaaL]A_Lm]VLNpmq_A^VA_LwV]LœlNpUApASSNJp!amAngeles County.
Goal 1 (see above). Previous goal replaced
with new goal.
7.3 Existing Mitigation Capabilities The mitigation strategies developed as part of this AHMP seek to maximize existing ^VpVTApVa_JAiAIV]VpVNmVLN_pVœNLAmJqllN_p]yAvAV]AI]NwVpUV_pUN!am_TN]Nmaq_py%iNlApVa_A]lNA3UNmNNxVmpV_TJAiAIV]VpVNmUAvNINN_qiLApNLpalNŔNJpJUA_TNmV_humA_pNJU_VJA]œ_A_JVA]]NTA]lNTq]ApalyNLqJApVa_A_LaqplNAJUlNmaqlJNmmV_JNthe 2020 AHMP.
County of Los Angeles
All-Hazards Mitigation Plan
7.3.1 qpUalVpVNm-a]VJVNmA_L!NTA]0NTq]Apaly0NmaqlJNmThere are several NxVmpV_TAqpUalVpVNmia]VJVNmA_LapUNl]NTA]allNTq]ApalylNmaqlJNmapplicable to hazard mitigation efforts in Los Angeles County. From the County Code aS%lLV_A_JNm pa Ja^i]NpNLi]A_m pUNmNSal^ pUN Jal_Nlmpa_NaSUA|AlL^VpVTApVa_activities by provVLV_T A Saq_LApVa_ laapNL V_ LApA lNmNAlJU i]A__V_T 3NJU_VJA]Ecological Knowledge (TEK) provided by our state and locally recognized indigenous Ja^^q_VpVNmA_LN]NJpNLaSœJVA]m¯AqpUalVpyThe County aims to expand and improve upon pUNmN VLN_pVœNL JAiAIV]VpVNm Iy ALaipV_T pUVm "- a_JN AiilavNL V_pa pUN Safety Element of the Los Angeles County General Plan. This action will contribute to the County’s ability to be considered for an additional cost-share on Public Assistance projects through the California Disaster Assistance Act. Table 7-2 provides an overview aSNxVmpV_TJAiAIV]VpVNmlN]ApNLpaAqpUalVpVNmia]VJVNmA_L]NTA]lNTq]ApalylNmaqlJNm Table 7-2 qpUalVpVNm-a]VJVNmA_L!NTA]0NTq]Apaly0NmaqlJNm Authority, Policy, or 0NmaqlJN
Description Hazards Addressed Potential to Affect Development Los Angeles County Operational Area Emergency Operations Plan (2023) Establishes the coordinated emergency management system within the Los Angeles County %iNlApVa_A]lNApailNiAlNSallNmia_LpaA_LlNJavNlSla^pUNeffects of large-scale emergencies lNTAlL]NmmaSJAqmN]aJApVa_alcomplexity.
All-Hazard No
Los Angeles County General Plan (2024)
Provides the policy framework for how and where the unincorporated County will grow through the year 2035.
All-Hazard Yes
Los Angeles County Comprehensive Floodplain
0NvVNwmNxVmpV_TŔaaLi]AV_management programs in the County and recommends enhancements to them through 35 Flood Land Movement
Yes
County of Los Angeles All-Hazards Mitigation Plan
Authority, Policy, or 0NmaqlJN
Description Hazards Addressed Potential to Affect Development Management Plan (2021)
mitigation actions. This plan is currently being reviewed and updated with completion targeted for early 2026.
Los Angeles County Comprehensive Floodplain Management Plan Repetitive Loss Area Analysis (2021) Analyzes Repetitive Los Areas within Los Angeles County and Sq]œ]]ma^^q_Vpy0ApV_T1ympN^requirements.
Flood Land Movement
Yes
County of Los Angeles Floodplain Management Plan Progress Report (2024) Provides an annual update on the implementation of the action plan VLN_pVœNLV_pUNa^ilNUN_mVvNFloodplain Management Plan and on the implementation and evaluation of outreach projects.
Flood Land Movement
Yes
County of Los Angeles Repetitive Loss Area Analysis Progress Report (2023) Provide an annual update on the implementation of the action plan VLN_pVœNLV_pUNRepetitive Loss Area Analysis to ensure there is a continuing and responsive planning process.
Flood Yes
Los Angeles County Fire Plan (2023)
NmJlVINmpUNwV]LœlNN_vVla_^N_pUVmpalyA_LilN-œlNmanagement strategies to N_UA_JNpUNilapNJpVa_aS]VvNmilaiNlpyA_L_ApqlA]lNmaqlJNmSla^wV]L]A_LœlN :V]LœlN Yes
County of Los Angeles
All-Hazards Mitigation Plan
Authority, Policy, or 0NmaqlJN
Description Hazards Addressed Potential to Affect Development Los Angeles County 2045 Climate Action Plan (2024)
Delineates the County’s path toward meeting the goals of the Paris Agreement and achieving carbon neutrality for unincorporated Los Angeles County. :V]LœlNExtreme Heat Drought Flooding
Yes
Our County: Los Angeles Countywide Sustainability Plan (2019) Outlines how local governments and stakeholders can enhance the well-being of all County communities while adapting to climate change and reducing damage to the natural N_vVla_^N_piAlpVJq]Al]ySaJqmV_Ton communities disproportionately burdened by pollution. :V]LœlNExtreme Heat Drought Flooding
Yes
Los Angeles County Floodplain Management Ordinance
Aims to minimize public and ilVvApN]ammNmlNmq]pV_TSla^ŔaaLconditions via uniformly applied lNTq]ApVa_mV_ŔaaLila_N^qLŔawalŔaaLlN]ApNLNlamVa_areas.
Flood Land Movement
Yes
Los Angeles County Code – Title 32: Fire Code
To build a new structure (or an addition equal to or greater than ÈaSNxVmpV_TmkqAlNSaapATN the Los Angeles County Fire Code lNkqVlNmlNvVNwaSVpm]aJApVa_pyiNaSJa_mplqJpVa_paiaTlAiUym]aiNamount and arrangement of vNTNpApVa_A_LavNlA]]site :V]LœlN Yes
County of Los Angeles All-Hazards Mitigation Plan
Authority, Policy, or 0NmaqlJN
Description Hazards Addressed Potential to Affect Development settings—in order to create defensible space necessary for NSSNJpVvNœlNilapNJpVa_aSUa^Nmin High Fire Severity Zones.
Los Angeles County Code – Title 22: Planning and Zoning Establishes the regulations governing land use and LNvN]ai^N_pA_LLNœ_Nm|a_V_Tfor unincorporated Los Angeles County. Includes the Hillside Management Area Ordinance UAipNl pUN0NmVLN_pVA]NmVT_1pA_LAlLm%lLV_A_JNA_Lthe Hillside Design Guidelines. These include requirements for development in Hillside "A_ATN^N_plNAmwUVJUAlNLNœ_NLAmAlNAmwVpU Èalgreater natural slopes. The TqVLN]V_NmV_J]qLNmiNJVœJA_Lmeasurable design techniques that JA_INAii]VNLpalNmVLN_pVA]commerciA]V_LqmplVA]A_LapUNltypes of projects. :V]LœlNEarthquake Land Movement
Yes
Los Angeles County Code – Title 31: Green Building Standards Code Enhances the design and construction of buildings via building concepts with positive (or reduced negative) environmental V^iAJpmA_LN_JaqlATNmsustainable construction practices Extreme Heat Drought
Yes
County of Los Angeles
All-Hazards Mitigation Plan
Authority, Policy, or 0NmaqlJN
Description Hazards Addressed Potential to Affect Development AJlammi]A__V_TA_LLNmVT_N_NlTyNSœJVN_JywApNlJa_mNlvApVa_^ApNlVA]A_LlNmaqlJNNSœJVN_JyA_Lenvironmental air quality.
Los Angeles County Brush Clearance Program
Legally declares both improved and unimproved properties a iqI]VJ_qVmA_JNA_LwUNlN_NJNmmAlylNkqVlNmpUNJ]NAlA_JNof hazardous vegetation thereby creating defensible space for NSSNJpVvNœlNilapNJpVa_aSilaiNlpy]VSNA_LpUNN_vVla_^N_pThe Brush Clearance Program is a joint effort between the County of Los Angeles Fire Department and the County of Los Angeles Department of Agricultural Commissioner/Weights and Measurem:NNLA|AlLA_L-NmpAbatement Bureau (Weed Abatement Division). :V]LœlN Yes
Los Angeles County Code – Title 26: Building Code
Provides minimum standards to regulate pUNLNmVT_Ja_mplqJpVa_V_mpA]]ApVa_kqA]VpyaS^ApNlVA]mqmNaJJqiA_Jy]aJApVa_A_L^AV_pN_A_JNaSA]]IqV]LV_TmmplqJpqlNmTlALV_TA_LJNlpAV_equipment. Regulates construction Earthquake :V]LœlN
Yes
County of Los Angeles All-Hazards Mitigation Plan
Authority, Policy, or 0NmaqlJN
Description Hazards Addressed Potential to Affect Development near a known active earthquake SAq]pUAipNl1NJpVa_ pUNmaterials and construction methods for construction in a Wildland-Urban Interface (WUI) VlNlNAUAipNl mplqJpqlA]design as it relates to earthquake UA|AlLmUAipNl1NJpVa_16 lNiAVlaSJNlpAV_IqV]LV_TmV_High Earthquake Damage Areas UAipNl NAlpUkqA\NUA|AlLreduction for concrete tilt-up buildings (Chapter 95) and unreinforced masonry buildings UAipNl A^a_TapUNlm3UNBuilding Code also includes provisions for emergency housing during a proclaimed emergency.
7.3.2 Human and Technical Resources Existing human and technical resources across County Departments enable the aq_pypai]A_^A_ATNJa_LqJpA_LNxNJqpNVpmwVLNlA_TNaSUA|AlL^VpVTApVa_activities. The resources below represent a high degree of expertise in all facets of hazard mitigation available to support mitigation activities. The County aims to NxiA_LA_LV^ilavNqia_pUNmNVLN_pVœNLJAiAIV]VpVNmIyNxiA_LV_Tpotential hazard training opportunities available to the Los Angeles County Operational Area. LLVpVa_A]]yAmvAlVaqmmpecial events are scheduled in Los Angeles County over the _NxpœvNyNAlmpUNaq_pyshould seek to expand coordination and technical resources lN]ApNLpa^AmmvVa]N_JNJyINlA_LapUNlmiNJVA]NvN_p-related hazards.
County of Los Angeles
All-Hazards Mitigation Plan
Table 7-3 provides an overview of existing capabilities related to human and technical resources.
Table 7-3 q^A_A_L3NJU_VJA]0NmaqlJNm
0NmaqlJN Department/Agency -lV_JViA]JpVvVpVNm0N]ApNLpaA|AlL Mitigation
Emergency Management Coordinator(s)
Los Angeles County %SœJNaS^NlTN_JyManagement
x Maintains and updates the Los
Angeles County Operational Area Emergency Operations Plan and Los Angeles County All-Hazard Mitigation Plan. x Coordinates local response and
recovery activities in the Emergency Operation Center A_LV_pUNœN]L x Wal\mJ]amN]ywVpU]aJA] mpApNA_L
federal partners to support planningtrainingNxNlJVmNiqI]VJV_Sal^ApVa_and resource coordination. _TV_NNlm Building _miNJpalm Code Enforcement %SœJNlm VlN"AlmUA]]mA_LOther Technical Staff Los Angeles County Public Works and Fire Department
x %vNlmNNmpUNNSSNJpVvNNSœJVN_pSAVl
and safe enforcement of County of Los Angeles Building and Fire Codes. _TV_NNlm Construction Project "A_ATNlmA_LOther Technical Staff Los Angeles County Public Works
x Provides direct (or contract) JVvV]
mplqJpqlA]A_L^NJUA_VJA]N_TV_NNlV_TmNlvVJNm including Ja_plAJpila[NJpA_LJa_mplqJpVa_management. _TV_NNlm Project
Los Angeles County Public Works
x Maintains and operates a wide range
of local equipment and facilities and assists members of the public by County of Los Angeles All-Hazards Mitigation Plan
0NmaqlJN Department/Agency -lV_JViA]JpVvVpVNm0N]ApNLpaA|AlL Mitigation
"A_ATNlm Equipment OiNlApalmMaintenance and Construction StaffA_L%pUNlTechnical Staff ilavVLV_TmqSœJVN_pJ]NA_SlNmUwApNlreliable mNwNlmNlvVJNmmplNNp^AV_pN_A_JNmpal^LlAV_ATNmympN^mmplNNpJ]NA_V_TmplNNp]VTUpmA_LplASœJmVT_A]m Floodplain Administrator
Los Angeles County Public Works
x _SalJNmpUNŔaaLi]AV_^A_ATN^N_p
ordinance ensuring that development proposals do not V_JlNAmNŔaaLlVm\A_LpUAp_Nwdevelopments are not located below the 100-yNAlŔaaL]NvN]_ALLVpVa_pUNŔaaLi]AV_AL^V_VmplApalVmresponsible for planning and ^A_ATV_TŔaaLlVm\lNLqJpVa_projects throughout Los Angeles County. -]A__Nlm _TV_NNlm A_LTechnical Staff
Los Angeles County Department of Regional Planning
x Develops and maintains the Los
_TN]Nmaq_pyN_NlA]-]A_including the Safety Element. x Develops area plans based on the
Los Angeles County General Plan to ilavVLN^alNmiNJVœJTqVLA_JNSalpUNLNvN]ai^N_paS^alNmiNJVœJareas. x 0NvVNwmilaiamNLLNvN]ai^N_p
JAiVpA]V^ilavN^N_pmA_LapUNlphysical projects involving property for consistency and conformity with the Los Angeles County General Plan. x Anticipates and acts on the need for
Aii]VJAI]N_Nwi]A_mia]VJVNmA_Lcode changes.
County of Los Angeles
All-Hazards Mitigation Plan
0NmaqlJN Department/Agency -lV_JViA]JpVvVpVNm0N]ApNLpaA|AlL Mitigation x ii]VNmpUNAiilavNLi]A_mia]VJVNm
JaLNilavVmVa_mA_LapUNlregulations to proposed land uses.
Procurement Services Manager
Los Angeles County Internal Services Department
x Provides a full range of municipal
œ_A_JVA]mNlvVJNmand administers several licensing measures.
Comptroller Personnel
Los Angeles County Auditor – Controller
x -lavVLNmœ_A_JVA]and grant services.
County Counsel Personnel
Los Angeles County Counsel
x Provides legal services for the
County.
Fire Department Personnel
Los Angeles County Fire Department
x -lavVLNmœlNilapNJpVa_mNlvVJNm
V_J]qLV_TlNmia_mNœlNilNvN_pVa_and mitigation activities for the County.
Sheriff’s Department Personnel
Los Angeles County Sheriff’s Department
x Provides law enforcement services in
the County.
7.3.3 Financial Resources and Programs 3UNlN AlN ^A_y NxVmpV_T œ_A_JVA] lNmaqlJNm TlA_p ilaTlA^m A_L apUNl Sq_LV_Tmechanisms that enable current and future hazard mitigation activities. Sources for these resources and programs vary widely from local funding out of the County’s General Fund to state and federal programs that aim to help local jurisdictions accomplish their hazard mitigation goals. The amount of funding available is variable and project-miNJVœJSal^A_yaSpUNmNilaTlA^m1V^V]Al]yTlA_pAwAlLmAlNIAmNLa_pUNmiNJVœJila[NJpmpUApAlNVLN_pVœNLAmpUNIAmVmSalpUNTlA_pAii]VJApVa_3AI]N-4 ilavVLNm A_ avNlvVNw aS NxVmpV_T JAiAIV]VpVNm lN]ApNL pa œ_A_JVA] lNmaqlJNm A_Lprograms.
County of Los Angeles All-Hazards Mitigation Plan
Table 7-4 V_A_JVA]0NmaqlJNmA_L-laTlA^m
0NmaqlJNal
Program Administrator Purpose
General Fund
Chief Executive %SœJN
-laTlA^aiNlApVa_mA_LmiNJVœJila[NJpm
General Obligation Bonds
Auditor - Controller
General obligation bonds are appropriately used for the construction and/or acquisition of improvements to real property broadly available to residents and visitors. Such facilities include but are not limited to: ]VIlAlVNmUamiVpA]m iAl\miqI]VJmASNpySAJV]VpVNmA_Lcultural and educational facilities.
Special Tax and Revenue Bonds Controller
0NvN_qNIa_LmAlNqmNLpaœ_A_JNJAiVpA]projects that: 1. HAvNA_VLN_pVœNLIqLTNpAlymplNA^Sal lNiAy^N_pNTmiNJVœNLSNNmpAxlNJNVipm
2. Generate project revenue but rely on a
broader pledge of general fund revenues to lNLqJNIallawV_TJampmal
3. Finance the acquisition and installation of
equipment for the local jurisdiction’s general governmental purposes.
Vegetation Management Program
Cal FIRE
Cost-sharing program between Cal FIRE and private landowners which focuses on the use of ilNmJlVINLœlNA_L/or ^NJUA_VJA]^NA_mSalALLlNmmV_TwV]L]A_LœlNSqN]UA|AlLmA_LapUNlresource management issues on State Responsibility Area (SRA) lands. :V]LœlNEmergency and Mitigation Funds
Cal FIRE Administers funding from FEMA Bureau of Land "A_ATN^N_p and U.S. Forest Service for County of Los Angeles
All-Hazards Mitigation Plan
0NmaqlJNal
Program Administrator Purpose
certain types of wV]LœlN emergency and mitigation funding.
California Residential Mitigation Program
California Earthquake Authority
Created by the California Earthquake Authority A_LpUNavNl_al¯m%SœJNaS^NlTN_Jy1NlvVJNm¬Earthquake Brace + Bolt: Funds to Strengthen Your Foundation” is the œlmpincentive program offered by the California Residential Mitigation Program.
Public Health Emergency Preparedness Cooperative Agreement Center for Disease Control and Prevention
Funds are intended to upgrade state and local public health jurisdictions’ preparedness and response to IVapNllalVm^ outbreaks of infectious LVmNAmNm and other public health threats and emergencies.
Hazard Mitigation Grant Program (HMGP)
FEMA
Administered by the California Governor’s %SœJNaS^NlTN_Jy1NlvVJNmA]%1 "-supports pre- and post-disaster mitigation plans and projects available to California communities after a presidentially declared disaster has occurred in California.
Pre-Disaster Mitigation (PDM) Grant Program
FEMA
Available annually as a nationally competitive A]%1TlA_ppUN-"lA_p-laTlA^supports pre-disaster mitigation plans and projects.
Flood Mitigation Assistance (FMA) Grant Program
FEMA
Available annually as a nationally competitive A]%1TlA_ppUN-"lA_p-laTlA^supports pre-disaster mitigation plans and projects.
Homeland Security
FEMA Builds and sustains preparedness technical assistance activities in support of the four County of Los Angeles All-Hazards Mitigation Plan
0NmaqlJNal
Program Administrator Purpose
Preparedness Technical Assistance Program
Ua^N]A_LmNJqlVpy^VmmVa_AlNAmVNilNvN_pVa_ilapNJpVa_lNmia_mNlNJavNly A_Lhomeland security program management.
Assistance to VlNœTUpNlm Grant Program
FEMA/U.S. Fire Administration
-lavVLNmNkqVi^N_pilapNJpVvNTNAlN^NlTN_JyvNUVJ]NmplAV_V_TA_LapUNlresources needed to protect the public and emergency personnel from œlN and related UA|AlLmvAV]AI]NpaœlNLNiAlp^N_pmA_L_a_ASœ]VApNLN^NlTN_Jy^NLVJA]mNlvVJNmproviders.
Land and Water Conservation Funds
U.S. Department of the Interior
Supports the protection of federal public lands and waters and voluntary conservation on private land.
Community Action for a Renewed Environment
U.S. Environmental Protection Agency (EPA)
Offers means by which communities may organize/take action to reduce toxic pollution NTV_mpal^wApNlNpJ pUlaqTUœ_A_JVA]A_Ltechnical assistance. Communities create partnerships that implement solutions to reduce releases of toxic pollutants and that minimize toxic exposures.
Clean Water State Revolving Fund
EPA
A loan program that provides low-cost œ_A_JV_T to eligible entities on state and tribal lands for water quality ila[NJpmV_J]qLV_TA]]types of non-iaV_pmaqlJNwApNlmUNLilapNJpVa_allNmpalApVa_NmpqAly^A_ATN^N_pila[NJpmA_L^alNplALVpVa_A]^q_VJViA]wastewater treatment projects.
County of Los Angeles
All-Hazards Mitigation Plan
0NmaqlJNal
Program Administrator Purpose
Community Block Grant Program Entitlement Communities Grants U.S. Department of Housing and Urban Development
JkqVmVpVa_aSlNA]ilaiNlpylN]aJApVa_A_LLN^a]VpVa_lNUAIV]VpApVa_aSlNmVLN_pVA]A_Lnon-lNmVLN_pVA]mplqJpqlNmJa_mplqJpVa_aSiqI]VJSAJV]VpVNmA_LV^ilavN^N_pmNTwApNlmNwNlSAJV]VpVNmmplNNpmneighborhood JN_pNlmNpJ and the conversion of school buildings for eligible purposes.
High Hazard Potential Dams (HHPD) Grant Program
FEMA
PlavVLNm pNJU_VJA] i]A__V_T LNmVT_ A_Lconstruction assistance in the form of grants for the rehabilitation of eligible high hazard potential dams.
State and Local Cybersecurity Grant Program
FEMA
Provides funding to eligible entities to address cybersecurity risks and threats to information mympN^maw_NLalaiNlApNLIyala_INUA]SaSmpApN]aJA]alplVIA]TavNl_^N_pm.
7.3.4 Education and Outreach Resources Engagement with the communities of Los Angeles County is an important component aS^VpVTApVa_NSSalpm3UNaq_pyaS!am_TN]NmUAm^q]pVi]N^NpUaLmSal^ApmA_Lvenues to conduct outreach with community members and provide education on the hazard landscape in Los Angeles County. These activities ensure mitigation efforts align with community goals and include community input. Table 7-5 shows a list of existing resources for education and outreach.
Table 7-5 LqJApVa_A_L%qplNAJU0NmaqlJNm
0NmaqlJNalProgram
Agencies Potentially Involved Purpose
Preparedness Fairs
%SœJNaS^NlTN_Jy"A_ATN^N_pVlN
Engage with community members to provide education
County of Los Angeles All-Hazards Mitigation Plan
0NmaqlJNalProgram
Agencies Potentially Involved Purpose NiAlp^N_p1UNlVSS¯mNiAlp^N_p-qI]VJ:al\mBoard of Supervisors on hazards found in Los Angeles County and emergency preparedness for homes and businesses.
Personal Disaster Impact Surveys
%SœJNaS^NlTN_JyManagement
Receive input and feedback on the hazard landscape from community members in Los Angeles County to inform the 2025 AHMP.
AHMP Draft Review Surveys
%SœJNaS^NlTN_JyManagement
Receive input and feedback on sections of the AHMP from community members in Los Angeles County.
Homeless Outreach Services Team (HOST)
1UNlVSS¯mNiAlp^N_pHomelessness Services Organizations Conduct outreach to People Experiencing Homelessness in AlNAmila_NpawV]LœlNmalŔaaLV_TIAmNLa_wNApUNlconditions.
Community Emergency Response Teams (CERT)
Fire Department
Educate community members about disaster preparedness and response in their communities.
Explorer Programs
VlNNiAlp^N_p1UNlVSS¯mDepartment
Educate youth about disaster preparedness and response in their communities.
Youth Climate Commission UVNS1qmpAV_AIV]Vpy%SœJN
Educate and obtain input from youth on climate change impacts and mitigation efforts.
County of Los Angeles
All-Hazards Mitigation Plan
7.3.5 National Flood Insurance Program Participation The National Flood Insurance Program (NFIP) is administered by FEMA and provides ASSalLAI]N ŔaaL V_mqlA_JN pa iAlpVJViApV_T Ja^^q_VpVNm pUlaqTU A _Npwal\ aSinsurance providers. NFIP regulations must be enforced in Special Flood Hazard Areas (SFHAs). Flood insurance is required for structures in SFHAs with federally backed loans NT^amp^alpTATNm1^A]] qmV_NmmL^V_VmplApVa_ 1
]aA_m A_L"TlA_pmA]a_TwVpUA_ymplqJpqlNmwVpU1 ]aA_mlNTAlL]NmmaSŔaaL|a_N]aaLV_mqlA_JNVmrequired to IN^AV_pAV_NLSalpUN]VSNaSpUNSNLNlA]]yIAJ\NL]aA_A_LV_iNliNpqVpylNTAlL]NmmaSJUA_TNV_aw_NlmUViV_pUNJAmNaS"TlA_pmThe Los Angeles County Board of Supervisors adopted the County Floodway %lLV_A_JN !am _TN]Nm aq_py aLN 3Vp]N UAipNl V_ "AlJU 3UVmalLV_A_JNV_J]qLNLpUNœlmpaq_py]aaLwAy"AimA_LiAvNLpUNwAySalpUNaq_pyto begin participation in NFIP on behalf of unincorporated residents. The County’s participation means that residents (owners and renters) in the unincorporated Ja^^q_VpVNm wVpUV_ !am _TN]Nm aq_py AlN N]VTVI]N Sal #- ŔaaL V_mqlA_JN A_LNLNlA]ŔaaLLVmAmpNlAmmVmpA_JN3UNœlmp"]aaL_mqlA_JN0ApN"Aim 0"m INJA^NNSSNJpVvNa_NJN^INl1V_JNpUNaq_pyUAmJa_pV_qNLlaIqmpparticipation in NFIP. The FEMA FIRMs were digitized in September 2008 and have been revised over the years by numerous Letters of Map Change and by large-scale Physical Map Revisions for the Ballona Creek watershed and several watersheds in the 1A_pA"a_VJA"aq_pAV_m 3lVq_Sa lNN\3aiA_TA A_ya_ A_L apUNlm V_ NJN^INl pUN !am _TN]Nm aq_py JaAmp]V_N V_ ilV] A_L the Santa Clara River watershed in June 2021. These maps are available to the public on the Los Angeles County Public Works (PW) website at dpw]AJaq_pyTavŔaaL|a_NLos Angeles County also participates in the NFIP’s Community Rating System (CRS) program. The CRS program is a voluntary program for communities that engage in Ja^^q_Vpy ŔaaLi]AV_ ^A_ATN^N_p AJpVvVpVNm wUVJU NxJNNL pUN ^V_V^q^ #- standards. CRS communipVNm IN_Nœp Sla^ A LVmJaq_p a_ ŔaaL V_mqlA_JN lApNm A_LV^ilavNLŔaaLi]AV_^A_ATN^N_pilaTlA^m01qmNmAJ]AmmlApV_TmympN^INpwNN_A_LpaLNpNl^V_NŔaaLV_mqlA_JNilN^Vq^lNLqJpVa_mSallNmVLN_pmmaSilV] !am_TN]Nm aq_pyVm A ]Amm 01 Ja^^q_Vpy pUNlNSalNUa^Naw_Nlm A_L County of Los Angeles All-Hazards Mitigation Plan
lN_pNlmwUa]VvNV_A1JA_lNJNVvNqipaAÈLVmJaq_pa_pUNVlŔaaLV_mqlA_JNpolicies. 3UN aq_py¯m V^i]N^N_pApVa_ A_L N_SalJN^N_p aS ]aJA] ŔaaLi]AV_ ^A_ATN^N_pregulations for development in SFHAs are covered in Los Angeles County Building aLNmwVpU pUN^amplNJN_pqiLApNJa^i]NpNLV_3Vp]NUAipNlV_J]qLNmrequirements for dNvN]ai^N_pwVpUV_ ŔaaLUA|AlL AlNAm%pUNl lN]NvA_palLV_A_JNmV_J]qLNapUNlJUAipNlmV_3Vp]N qV]LV_TaLN A]a_TwVpU3Vp]Nm]NJplVJA]aLN 3Vp]N-]q^IV_TaLN 3Vp]N"NJUA_VJA]aLN 3Vp]N0NmVLN_pVA]aLN A_LTitle 33 (Existing Building Code). Implementation and enforcement are also covered in the Los Angeles County Subdivision Code (Title 21) and Planning and Zoning Code (Title 22). The NFIP for unincorporated communities is administered by the Department of Public Works (L-: 1pal^wApNl _TV_NNlV_T VvVmVa_ wUVJU mNlvNm Am pUNaq_py¯mŔaaLi]AV_^A_ATNlJaalLV_ApNmwVpU!-:¯m qV]LV_TA_L1ASNpyA_L!A_LDevelopment Divisions and with the Los Angeles County Department of Regional Planning in their enforcement of the aq_py¯mŔaaLi]AV_^A_ATN^N_plNTq]ApVa_mA_LiAlpVJViApNmV_ "¯ma^^q_VpymmVmpNL9VmVpmwUVJU pyiVJA]]y aJJqla_ A -year cycle. LACPW continues to enforce NFIP regulations for building permit applications LNpNl^V_NLIy qV]LV_TA_L1ASNpyaSœJVA]mpaINmqImpA_pVA]V^ilavN^N_pallNiAVlaSsubstantial damage. Los Angeles County also requires all residential buildings undertaking sqImpA_pVA]V^ilavN^N_ppaUAvNpUNVl]awNmpŔaalN]NvApNLSaapAIavN the 100-yNAlŔaaLN]NvApVa_LLVpVa_A]]y!am_TN]Nmaq_pyJa_LqJpNLA0NiNpVpVvN!ammlNA_A]ymVmV_wUVJUmNlvNmAmAmiNJVœJi]A_SallNLqJV_TLA^ATNSla^ŔaaLV_TV_lepetitive loss areas. SpNlA_NvN_p-qI]VJ:al\mmpASSAmmNmmpUNq_V_JalialApNLAlNAIqV]LV_TmwVpUV_pUNextent of the event. The assessment will identify the buildings that appear to have damages affecting 50 percent or greater of the building. SmqJUAIqV]LV_TVmV_Ŕoodila_NAlNAmVLN_pVœNLIy"¯m]aaL_mqlA_JN0ApN"Aimaq_py^Aim]aaLwAy"AimalmmNmmal¯m"Aim alVLN_pVœNLIy-qI]VJ:al\mpaINV_A0NiNpVpVvN!ammlNAwill undergo further evaluation by Public Works staff on whether the building meets "¯mLNœ_VpVa_aSmqImpA_pVA]V^ilavN^N_pmqImpA_pVA]LA^ATN11 A building pUAp ^NNpm "¯m 11 LNœ_VpVa_ wV]] IN lNkqVlNL pa UAvN pUN N_pVlN IqV]LV_Tupgraded to meet National Flood Insurance Program (NFIP) standards ( Title 44aLN County of Los Angeles
All-Hazards Mitigation Plan
aSNLNlA]0NTq]ApVa_m1NJpVa_ . !am_TN]Nmaq_pyaLN3Vp]N1NJpVa_ requires the County to enforce as a minimum the current Federal Flood Plain "A_ATN^N_p 0NTq]ApVa_m LNœ_NL V_ Title 44 aLN aS NLNlA] 0NTq]ApVa_m 1NJpVa_ SalIqV]LV_TmmplqJpqlNmA_LTlALV_T]aJApNLV_wUa]NalV_iAlpV_ŔaaLUA|AlLareas. (Ord. 2013-Í%lL- Í%lL
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ÍiAlp 1995.) 7.4 LN_pVœJApVa_A_L_A]ymVmaS"VpVTApVa_Strategies -apN_pVA]^VpVTApVa_AJpVa_mwNlNVLN_pVœNLSalNAJUUA|AlLVLN_pVœNLV_1NJpVa_6 in an effort to ensure as comprehensive a mitigation strategy as possible. Multiple mitigation options were then analyzed against the goals and objectives delineated in this section with a focus on new and existing buildings. A combination of new and ongoing ^VpVTApVa_ AJpVa_m AV^NL Ap lNLqJV_T pUN NSSNJpm aS pUN VLN_pVœNL UA|AlLm wNlNcompiled into the list of mitigation actions in the following subsection. This list includes AwVLNlA_TNaSiapN_pVA]pyiNmaS^VpVTApVa_AJpVa_mV_J]qLV_T x Local Plans and Regulations. x Structure and Infrastructure Projects. x Natural Systems Protection. x Education and Awareness Programs.
A notable update to the 2025 AHMP was the integration of human-caused threats and corresponding potential mitigation actions. The AHMP Planning Team also reviewed FEMA’s Mitigation Ideas document to incorporate national best practices in the list of potential mitigation actions.
County of Los Angeles All-Hazards Mitigation Plan
7.4.1 Mitigation Strategies
01 Title: 1qiialpA_LxiA_Laq_pywVLN9NTNpApVa_"A_ATN^N_pA_LVlN Prevention Efforts
1aqlJN Los Angeles County Fire DepartmentType: Natural Systems Protection Description: Conduct passive protection measures such as creating defensible space buffers around residential and non-residential structures through the removal of ŔA^^AI]N vNTNpApVa_ ^A_ATV_T A_Lal lNLqJV_TUA|AlLaqm SqN]m JlNApV_T œlNIlNA\m œlN-resistive landmJAiV_T A_L Ja_mplqJpVa_ A_L J]NAlV_T LNALvNTNpApVa_ A^a_T apUNlm _TATN V_LVTN_aqmJa^^q_VpVNm pa V_Sal^ vNTNpApVa_ ^A_ATN^N_p A_L œlNprevention practices aligned with Traditional Ecological Knowledge (TEK).
Hazard: :V]LœlNHazard: Severe Wind/Tornado
02 Title: _UA_JN a^^q_Vpy _TATN^N_p V_ :V]LœlN -lapNJpVa_ A_L Prevention
1aqlJN Los Angeles County Department of Regional PlanningType: Education and Awareness Programs Description: _TATNlNmVLN_pmA_LIqmV_NmmNmV_UVTUœlNrisk communities to educate them on community-focused ^VpVTApVa_ A_L lVm\ lNLqJpVa_ mplApNTVNm N^NlTN_JyilNiAlNL_NmmA_LNvAJqApVa_lNALV_NmmA_Laiialpq_VpVNmpaTNpV_va]vNLV_œlNmASNpy-related community initiatives. Engage indigenous communities to inform protection and prevention practices aligned with Traditional Ecological Knowledge (TEK).
Hazard: :V]LœlNHazard: Severe Wind/Tornado
County of Los Angeles
All-Hazards Mitigation Plan
03 Title: Perform Post-Fire Flooding, Debris Flow, and Mud ]aw 0Vm\ Assessments and Mitigation Activities
1aqlJN Los Angeles County Department of Public WorksType: Structure and Infrastructure Projects Description: a]]awV_T A wV]LœlN AmmNmm Iql_ mJAl SalmVT_VœJA_p^qLA_LLNIlVmŔawlVm\mpailaLqJN^qLA_LLNIlVm Ŕaw iUAmN ^Aim Sal œlmp lNmia_LV_T ATN_JVNm paprepare for potential evacuations. Recommend mitigation mplApNTVNmpailNvN_p^qLA_LLNIlVmŔawVmpacts.
Hazard: :V]LœlNHazard: Flooding
04 Title: Strengthen Operational Continuity Capabilities for Critical Facilities 1aqlJN Los Angeles County NiAlp^N_p-qI]VJNA]pUA^a_TapUNlmType: Structure and Infrastructure Projects Description: Conduct robust continuity planning to ensure the continued performance of essential functions in the event critical facilities are impacted by various hazards. Build capabilities that support operational continuity such as alternate or uninterrupted power mqii]y wal\SalJN development and cross-plAV_V_T N^NlTN_JyJa^^q_VJApVa_mA_LLApAIAJ\qialSAV]avNlUAlLwAlN Hazard: :V]LœlNHazard: Extreme HeatHazard: Severe Wind/TornadoHazard: Cyber Incidents County of Los Angeles All-Hazards Mitigation Plan
05 Title: Incorporate Hazards in Local Planning, Land Use, and Development Codes
1aqlJN Los Angeles County Department of Public Works and Regional PlanningType: Local Planning and Regulations Description: NvN]ai ^AV_pAV_ A_L ]NvNlATNopportunities to strengthen relevant ordinances that TavNl_ ]A_L qmN IqV]LV_T JaLNm A_L LNvN]ai^N_p V_high-risk hazard areas. Incorporate mitigation actions in Ja^^q_Vpy i]A__V_T mqJU Am a^^q_Vpy :V]LœlN -]A_mFlood MA_ATN^N_p-]A_m A_L pUNaq_pyN_NlA]-]A_among many others.
Hazard: :V]LœlNHazard: AlpUkqA\NHazard: Land MovementHazard: Severe Wind/TornadoHazard: Flooding 06 Title: Increase Public Awareness of Climate Change Effects on Local Hazards
1aqlJN Los Angeles County UVNS1qmpAV_AIV]Vpy%SœJNType: Education and Awareness Programs Description: Engage with communities on ways climate change impacts various natural hazards along with mitigation actions and available resources for climate adaptation and resilience. Efforts should focus on how communities can take action or support existing County programs including funding available to the public. Public N_TATN^N_pNSSalpmmUaq]LINAJJNmmVI]NN_mqlNiNai]Nwith Access and Functional Needs are included in aqplNAJU A_L qmN ^ApNlVA]m wVpU ^q]pVi]N ]A_TqATNoptions.
Hazard: :V]LœlNHazard: Extreme HeatHazard: DroughtHazard: Land MovementHazard: Severe Wind/TornadoHazard: Flooding County of Los Angeles
All-Hazards Mitigation Plan