March 2022
COUNTY OF MONTEREY
Carmel-by-the-Sea Del Rey Oaks
Gonzales Greenfield
King City Marina
Monterey Pacific Grove
Salinas Sand City
Seaside Soledad
Carmel Area Wastewater District
Monterey County Water Resources Agency
Monterey One Water
Monterey Regional Waste Management District
Moss Landing Harbor District
VOLUME 1
MULTI-JURISDICTIONAL HAZARD MITIGATION PLAN
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COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan
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MONTEREY COUNTY OFFICE OF EMERGENCY SERVICES
GERRY MALAIS, EMERGENCY MANAGER
TERESA MEISTER, SENIOR SECRETARY
KELSEY SCANLON, EMERGENCY SERVICES PLANNER
JUSTIN LIN, EMERGENCY SERVICES PLANNER
LAURA EMMONS, EMERGENCY SERVICES PLANNER
DANIEL GONZALEZ, EMERGENCY SERVICES PLANNER
LUBNA MOHAMMAD, COMMUNITY RESILIENCE PLANNER
TRACY MOLFINO, EMERGENCY SERVICES PLANNER
1322 NATIVIDAD RD, SALINAS, CA
[email protected]
831-796-1905
IT IS THE POLICY OF THE COUNTY OF MONTEREY THAT NO PERSON SHALL BE DENIED THE
BENEFITS OF OR BE SUBJECTED TO DISCRIMINATION IN ANY CITY PROGRAM , SERVICE, OR
ACTIVITY ON THE GROUNDS OF RACE , RELIGION, COLOR, NATIONAL ORIGIN , ENGLISH
PROFICIENCY, SEX, AGE, DISABILITY, SEXUAL ORIENTATION, GENDER IDENTITY, OR SOURCE OF INCOME. THE COUNTY OF MONTEREY ALSO REQUIRES ITS CONTRACTORS AND GRANTEES TO COMPLY WITH THIS POLICY.
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ACKNOWLEDGMENTS
The Monterey County Multi-Jurisdictional Hazard Mitigation Plan update was made possible through the dedicated efforts of each participating jurisdiction, stakeholders, members of the public, and the Monterey County Office of Emergency Services. The development of this plan would not have been possible without the dedication and commitment of the Hazard Mitigation Plan Steering Committee.
Participating jurisdictions include:
Monterey County
City of Carmel-by-the-Sea
City of Del Rey Oaks
City of Gonzales
City of Greenfield
City of King
City of Marina
City of Monterey
City of Pacific Grove
City of Salinas
City of Sand City
City of Seaside
City of Soledad
Monterey County Water Resources Agency
Carmel Area Wastewater District
Monterey One Water
Monterey Regional Waste Management District
Moss Landing Harbor District
Special thanks to the following partners who helped make this project possible:
Federal Emergency Management Agency (FEMA)
California Governor’s Office of Emergency Services (Cal OES) Monterey County Information Technology Department
The citizens of Monterey County are commended for their participation in the outreach strategy. This outreach success will set the course for the successful implementation of this plan during the next performance period.
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TABLE OF CONTENTS
Executive Summary ............................................................................................................ xxv Hazard Mitigation Overview .................................................................................................... xxv Updating the Monterey County Plan ....................................................................................... xxv Guiding Principle ..................................................................................................................... xxvi Scope and Authority ............................................................................................................... xxvi Plan Structure ........................................................................................................................ xxvii Risk Assessment ..................................................................................................................... xxvii Mitigation Goals ...................................................................................................................... xxix Hazard Problem Statements ................................................................................................... xxix Mitigation Action Plan ........................................................................................................... xxxii Implementation .................................................................................................................... xxxiii Part A: Planning and Community Profile ................................................................................ A
1. Introduction ................................................................................................................... 1-1
1.1 Hazard Mitigation Planning ............................................................................................... 1-2
1.1.1 Regulatory Framework ............................................................................................................. 1-2
1.1.2 Benefits of Mitigation Planning ................................................................................................ 1-3
1.2 Purpose of Planning and the Plan Update ......................................................................... 1-3
1.2.1 Objectives of the Plan Update .................................................................................................. 1-4
1.2.2 Participating Jurisdictions ......................................................................................................... 1-4
1.3 Contents of the Plan .......................................................................................................... 1-5
1.3.1 What’s New? ............................................................................................................................ 1-7
2. Planning Profile .............................................................................................................. 2-1
2.1 Planning Timeline ............................................................................................................... 2-2
2.1.1 The Steering Committee .......................................................................................................... 2-2
2.1.2 Stakeholder Engagement ......................................................................................................... 2-5
2.1.3 Jurisdiction Specific Planning Efforts ........................................................................................ 2-7
2.2 Public Engagement ............................................................................................................ 2-8
2.2.1 Website .................................................................................................................................... 2-8
2.2.2 Survey ....................................................................................................................................... 2-9 2 .2.3 Community Forums ................................................................................................................ 2-12
2.2.4 Public Presentations ............................................................................................................... 2-14
2.3 Assess the Risk ................................................................................................................. 2-15
2.4 Develop a Mitigation Strategy ......................................................................................... 2-15
2.5 Adopt and Implement the Plan ....................................................................................... 2-16
3. Community Profile .......................................................................................................... 3-1
3.1 Location, Geography, and Climate ..................................................................................... 3-1
3.2 History ................................................................................................................................ 3-3
3.3 Population and Demographics........................................................................................... 3-7 COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan
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3.3.1 Demographics ........................................................................................................................... 3-9
3.3.2 Income .................................................................................................................................... 3-10
3.3.3 Education ................................................................................................................................ 3-10
3.4 Housing ............................................................................................................................ 3-11
3.5 Local Economy ................................................................................................................. 3-12
3.6 Employment ..................................................................................................................... 3-14
3.7 Social Vulnerability .......................................................................................................... 3-16
3.7.1 Socioeconomic Status............................................................................................................. 3-18
3.7.2 Household Composition and Disability .................................................................................. 3-19
3.7.3 Minority Status and Language ................................................................................................ 3-20
3.7.4 Housing and Transportation ................................................................................................... 3-21
3.8 Land Use and Development Trends ................................................................................. 3-23 Part B: Hazard Profiles and Risk Assessment .......................................................................... B
4. Risk Assessment Methods ............................................................................................... 4-1
4.1 Hazard Identification ......................................................................................................... 4-1
4.1.1 Disaster Declaration History ..................................................................................................... 4-6
4.1.2 EOC Activations ...................................................................................................................... 4-10
4.2 Hazard Profiles ................................................................................................................. 4-11
4.3 Risk Assessment Methodology ........................................................................................ 4-12
4.3.1 Population and Asset Inventory ............................................................................................. 4-12
4.3.2 Hazard Exposure ..................................................................................................................... 4-16
4.3.3 Hazard Vulnerability ............................................................................................................... 4-18
4.3.4 Limitations .............................................................................................................................. 4-19
4.4 Hazard Prioritization and Risk Ranking ............................................................................ 4-19
4.4.1 Threat Hazard Risk Assessment Survey .................................................................................. 4-20
4.4.2 Ranking Methodology ............................................................................................................ 4-21
4.4.3 Results .................................................................................................................................... 4-22
5. Agricultural Emergencies ................................................................................................ 5-1
5.1 Overview ............................................................................................................................ 5-1
5.1.1 Natural Disasters & Severe Weather ........................................................................................ 5-1
5.1.2 Pests, Weeds, and Diseases ..................................................................................................... 5-2
5.2 Hazard Profile ..................................................................................................................... 5-3
5.2.1 History ...................................................................................................................................... 5-3
5.2.1 Location .................................................................................................................................... 5-6
5.2.2 Frequency ................................................................................................................................. 5-6
5.2.3 Severity ..................................................................................................................................... 5-7
5.2.4 Warning Time ........................................................................................................................... 5-7
5.3 Secondary Hazards ............................................................................................................. 5-7
5.4 Risk Assessment ................................................................................................................. 5-8
5.4.1 Population ................................................................................................................................ 5-8
5.4.2 Property .................................................................................................................................... 5-8
5.4.3 Critical Facilities and Infrastructure ....................................................................................... 5-12
5.4.4 Environment ........................................................................................................................... 5-12
5.4.5 Economic Impact .................................................................................................................... 5-13
5.5 Future Trends in Development ........................................................................................ 5-14 COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan
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5.6 Issues ................................................................................................................................ 5-14
6. Coastal Erosion ............................................................................................................... 6-1
6.1 Overview ............................................................................................................................ 6-1
6.1.1 Sand Mining in Monterey County ............................................................................................ 6-2
6.1.2 Types of Coastal Erosion .......................................................................................................... 6-2
6.2 Hazard Profile ..................................................................................................................... 6-3
6.2.1 History ...................................................................................................................................... 6-3
6.2.2 Location .................................................................................................................................... 6-5
6.2.3 Frequency ................................................................................................................................. 6-5
6.2.4 Severity ..................................................................................................................................... 6-6
6.2.5 Warning Time ........................................................................................................................... 6-6
6.3 Secondary Hazards ............................................................................................................. 6-6
6.4 Risk Assessment ................................................................................................................. 6-7
6.4.1 Population ................................................................................................................................ 6-7
6.4.2 Property .................................................................................................................................... 6-8
6.4.3 Critical Facilities and Infrastructure ......................................................................................... 6-9
6.4.4 Environment ........................................................................................................................... 6-10
6.4.5 Economic Impact .................................................................................................................... 6-10
6.5 Future Trends in Development ........................................................................................ 6-11
6.6 Issues ................................................................................................................................ 6-11
7. Dam and Levee Failure .................................................................................................... 7-1
7.1 Overview ............................................................................................................................ 7-1
7.1.1 Dam Failure .............................................................................................................................. 7-1
7.1.2 Levee Failure ............................................................................................................................ 7-2
7.1.3 Regulatory Oversight ................................................................................................................ 7-2
7.1.4 Dams in Monterey County ....................................................................................................... 7-5
7.1.5 Levees in Monterey County ................................ ..................................................................... 7-7
7.2 Hazard Profile ..................................................................................................................... 7-8
7.2.1 History ...................................................................................................................................... 7-8
7.2.2 Location .................................................................................................................................... 7-9
7.2.3 Frequency ............................................................................................................................... 7-13
7.2.4 Severity ................................................................................................................................... 7-14
7.2.5 Warning Time ......................................................................................................................... 7-15
7.3 Secondary Hazards ........................................................................................................... 7-16
7.4 Risk Assessment ............................................................................................................... 7-16
7.4.1 Population .............................................................................................................................. 7-16
7.4.2 Property .................................................................................................................................. 7-18
7.4.3 Critical Facilities and Infrastructure ....................................................................................... 7-21
7.4.4 Environment ........................................................................................................................... 7-22
7.4.5 Economic Impact .................................................................................................................... 7-22
7.5 Future Trends in Development ........................................................................................ 7-23
7.6 Issues ................................................................................................................................ 7-23
8. Drought .......................................................................................................................... 8-1
8.1 Overview ............................................................................................................................ 8-1
8.1.1 Drought in California ................................................................................................................ 8-2 COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan
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8.1.2 Drought Conditions .................................................................................................................. 8-2
8.1.3 Local Water Supply and Water Shortage ................................................................................. 8-4
8.2 Hazard Profile ..................................................................................................................... 8-5
8.2.1 History ...................................................................................................................................... 8-5
8.2.2 Location .................................................................................................................................... 8-8
8.2.3 Frequency ................................................................................................................................. 8-8
8.2.4 Severity ..................................................................................................................................... 8-9
8.2.5 Warning Time ......................................................................................................................... 8-10
8.3 Secondary Hazards ........................................................................................................... 8-10
8.3.1 Seawater Intrusion ................................................................................................................. 8-11
8.3.2 Wildfire ................................................................................................................................... 8-11
8.3.3 Debris Flows ........................................................................................................................... 8-11
8.4 Risk Assessment ............................................................................................................... 8-11
8.4.1 Population and Social Impacts ............................................................................................... 8-12
8.4.2 Economic Impact .................................................................................................................... 8-12
8.4.3 Environmental Impact ............................................................................................................ 8-13
8.5 Future Trends in Development ........................................................................................ 8-13
8.6 Issues ................................................................................................................................ 8-13
9. Earthquake ..................................................................................................................... 9-1
9.1 Overview ............................................................................................................................ 9-1
9.1.1 Earthquake Geology ................................................................................................................. 9-1
9.1.2 Earthquake Classifications ........................................................................................................ 9-3
9.1.3 Ground Motion ......................................................................................................................... 9-6
9.1.4 Liquefaction .............................................................................................................................. 9-7
9.2 Hazard Profile ..................................................................................................................... 9-8
9.2.1 History ...................................................................................................................................... 9-8
9.2.2 Location ................................ .................................................................................................... 9-9
9.2.3 Frequency ............................................................................................................................... 9-11
9.2.4 Severity ................................................................................................................................... 9-12
9.2.5 Warning Time ......................................................................................................................... 9-15
9.3 Secondary Hazards ........................................................................................................... 9-16
9.3.1 Dam and Levee Failure ........................................................................................................... 9-16
9.3.2 Landslides ............................................................................................................................... 9-16
9.3.3 Tsunamis ................................................................................................................................. 9-16
9.4 Risk Assessment ............................................................................................................... 9-16
9.4.1 Population .............................................................................................................................. 9-16
9.4.2 Property .................................................................................................................................. 9-17
9.4.3 Critical Facilities and Infrastructure ....................................................................................... 9-19
9.4.4 Environment ........................................................................................................................... 9-20
9.4.5 Economic Impact .................................................................................................................... 9-21
9.5 Future Trends in Development ........................................................................................ 9-21
9.6 Issues ................................................................................................................................ 9-21
10. Flooding ..................................................................................................................... 10-1
10.1 Overview ........................................................................................................................ 10-1
10.1.1 Floodplains ........................................................................................................................... 10-1
10.1.2 National Flood Insurance Program ....................................................................................... 10-2 COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan
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10.1.3 Types of Flooding ................................................................................................................. 10-5
10.1.4 Watersheds In Monterey County ......................................................................................... 10-7
10.2 Hazard Profile................................................................................................................. 10-8
10.2.1 History .................................................................................................................................. 10-8
10.2.2 Location .............................................................................................................................. 10-12
10.2.3 Frequency ........................................................................................................................... 10-15
10.2.4 Severity ............................................................................................................................... 10-16
10.2.5 Warning Time ..................................................................................................................... 10-16
10.3 Secondary Hazards ....................................................................................................... 10-17
10.4 Risk Assessment ........................................................................................................... 10-17
10.4.1 Population .......................................................................................................................... 10-17
10.4.2 Property .............................................................................................................................. 10-18
10.4.3 Critical Facilities and Infrastructure ................................................................................... 10-18
10.4.4 Environment ....................................................................................................................... 10-20
10.4.5 Economic Impact ................................................................................................................ 10-20
10.5 Future Trends in Development .................................................................................... 10-21
10.6 Issues ............................................................................................................................ 10-21
11. Hazardous Materials Incident ...................................................................................... 11-1
11.1 Overview ........................................................................................................................ 11-1
11.1.1 Types of Hazardous Materials Incidents .............................................................................. 11-2
11.1.2 Oversight .............................................................................................................................. 11-3
11.2 Hazard Profile................................................................................................................. 11-3
11.2.1 History .................................................................................................................................. 11-3
11.2.2 Location ................................................................................................................................ 11-5
11.2.3 Frequency ............................................................................................................................. 11-7
11.2.4 Severity ................................................................................................................................. 11-7
11.2.5 Warning Time ....................................................................................................................... 11-7
11.3 Secondary Hazards ......................................................................................................... 11-7
11.4 Risk Assessment ............................................................................................................. 11-8
11.4.1 Population ............................................................................................................................ 11-8
11.4.2 Property ................................................................................................................................ 11-9
11.4.3 Critical Facilities and Infrastructure ................................................................................... 11-10
11.4.4 Environment ....................................................................................................................... 11-11
11.4.5 Economic Impact ................................................................................................................ 11-11
11.5 Future Trends in Development .................................................................................... 11-11
11.6 Issues ............................................................................................................................ 11-11
12. Human-Caused Hazards .............................................................................................. 12-1
12.1 Overview ........................................................................................................................ 12-1
12.1.1 Cyber-Attack ......................................................................................................................... 12-2
12.1.2 Targeted Violence ................................................................................................................ 12-3
12.1.3 Terrorism .............................................................................................................................. 12-4
12.1.4 Mass Migration ..................................................................................................................... 12-7
12.2 Hazard Profile............................................................................................................... 12-10
12.2.1 History ................................................................................................................................ 12-10
12.2.2 Location .............................................................................................................................. 12-11
12.2.3 Frequency ........................................................................................................................... 12-14 COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan
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12.2.4 Severity ............................................................................................................................... 12-15
12.2.5 Warning Time ..................................................................................................................... 12-16
12.3 Secondary Hazards ....................................................................................................... 12-17
12.4 Risk Assessment ........................................................................................................... 12-17
12.4.1 Population .......................................................................................................................... 12-18
12.4.2 Property .............................................................................................................................. 12-18
12.4.3 Critical Facilities and Infrastructure ................................................................................... 12-19
12.4.4 Environment ....................................................................................................................... 12-21
12.4.5 Economic Impacts .............................................................................................................. 12-21
12.5 Future Trends in Development .................................................................................... 12-22
12.6 Issues ............................................................................................................................ 12-23
13. Public Health Hazards ................................................................................................. 13-1
13.1 Overview ........................................................................................................................ 13-1
13.1.1 Influenza ............................................................................................................................... 13-2
13.1.2 Coronaviruses ....................................................................................................................... 13-3
13.1.3 Viral Hemorrhagic Fevers ..................................................................................................... 13-5
13.1.4 Tick & Mosquito Borne Illness .............................................................................................. 13-6
13.1.5 Valley Fever .......................................................................................................................... 13-9
13.1.6 Policies, Plans, and Regulatory Environment ..................................................................... 13-10
13.2 Hazard Profile............................................................................................................... 13-11
13.2.1 History ................................................................................................................................ 13-11
13.2.2 Location .............................................................................................................................. 13-17
13.2.3 Frequency ........................................................................................................................... 13-17
13.2.4 Severity ............................................................................................................................... 13-18
13.2.5 Warning Time ..................................................................................................................... 13-18
13.3 Secondary Hazards ....................................................................................................... 13-18
13.4 Risk Assessment ........................................................................................................... 13-19
13.4.1 Population .......................................................................................................................... 13-19
13.4.2 Property .............................................................................................................................. 13-19
13.4.3 Critical Facilities and Infrastructure ................................................................................... 13-19
13.4.4 Environment ....................................................................................................................... 13-19
13.4.5 Economy ............................................................................................................................. 13-20
13.5 Future Trends in Development .................................................................................... 13-20
13.6 Issues ............................................................................................................................ 13-20
14. Severe Weather .......................................................................................................... 14-1
14.1 Overview ........................................................................................................................ 14-1
14.1.1 Severe Winter Storms .......................................................................................................... 14-2
14.1.2 Extreme Cold and Freeze...................................................................................................... 14-2
14.1.3 Windstorm ............................................................................................................................ 14-3
14.1.4 Extreme Heat ........................................................................................................................ 14-5
14.2 Hazard Profile................................................................................................................. 14-6
14.2.1 History .................................................................................................................................. 14-6
14.2.2 Location ................................................................................................................................ 14-8
14.2.3 Frequency ........................................................................................................................... 14-11
14.2.4 Severity ............................................................................................................................... 14-12
14.2.5 Warning Time ..................................................................................................................... 14-14 COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan
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14.3 Secondary Hazards ....................................................................................................... 14-14
14.4 Risk Assessment ........................................................................................................... 14-14
14.4.1 Population .......................................................................................................................... 14-14
14.4.2 Property .............................................................................................................................. 14-15
14.4.3 Critical Facilities and Infrastructure ................................................................................... 14-16
14.4.4 Environment ....................................................................................................................... 14-16
14.4.5 Economic Impact ................................................................................................................ 14-16
14.5 Future Trends in Development .................................................................................... 14-16
14.6 Issues ............................................................................................................................ 14-17
15. Slope Failure ............................................................................................................... 15-1
15.1 Overview ........................................................................................................................ 15-1
15.1.1 Types of Slope Failure .......................................................................................................... 15-1
15.1.2 Slope Failure Causes ............................................................................................................. 15-3
15.2 Hazard Profile................................................................................................................. 15-4
15.2.1 History .................................................................................................................................. 15-4
15.2.2 Location ................................................................................................................................ 15-7
15.2.3 Frequency ........................................................................................................................... 15-10
15.2.4 Severity ............................................................................................................................... 15-10
15.2.5 Warning Time ..................................................................................................................... 15-10
15.3 Secondary Hazards ....................................................................................................... 15-11
15.4 Risk Assessment ........................................................................................................... 15-12
15.4.1 Population .......................................................................................................................... 15-12
15.4.2 Property .............................................................................................................................. 15-12
15.4.3 Critical Facilities and Infrastructure ................................................................................... 15-13
15.4.4 Environment ....................................................................................................................... 15-14
15.4.5 Economic Impact ................................................................................................................ 15-15
15.5 Future Trends in Development .................................................................................... 15-15
15.6 Issues ............................................................................................................................ 15-15
16. Tsunami ...................................................................................................................... 16-1
16.1 Overview ........................................................................................................................ 16-1
16.1.1 Tsunami Types ...................................................................................................................... 16-3
16.2 Hazard Profile................................................................................................................. 16-3
16.2.1 History .................................................................................................................................. 16-3
16.2.2 Location ................................................................................................................................ 16-4
16.2.3 Frequency ............................................................................................................................. 16-7
16.2.4 Severity ................................................................................................................................. 16-7
16.2.5 Warning Time ....................................................................................................................... 16-9
16.3 Secondary Hazards ....................................................................................................... 16-10
16.4 Risk Assessment ........................................................................................................... 16-10
16.4.1 Population .......................................................................................................................... 16-10
16.4.2 Property .............................................................................................................................. 16-11
16.4.3 Critical Facilities and Infrastructure ................................................................................... 16-11
16.4.4 Environment ....................................................................................................................... 16-13
16.4.5 Economic Impact ................................................................................................................ 16-13
16.5 Future Trends in Development .................................................................................... 16-13 COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan
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16.6 Issues ............................................................................................................................ 16-13
17. Utility Interruption...................................................................................................... 17-1
17.1 Overview ........................................................................................................................ 17-1
17.1.1 Space Weather ..................................................................................................................... 17-3
17.2 Hazard Profile................................................................................................................. 17-6
17.2.1 History .................................................................................................................................. 17-6
17.2.2 Location ................................................................................................................................ 17-7
17.2.3 Frequency ............................................................................................................................. 17-7
17.2.4 Severity ................................................................................................................................. 17-7
17.2.5 Warning Time ....................................................................................................................... 17-8
17.3 Secondary Hazards ......................................................................................................... 17-8
17.4 Risk Assessment ............................................................................................................. 17-8
17.4.1 Population ............................................................................................................................ 17-8
17.4.2 Property ................................................................................................................................ 17-8
17.4.3 Critical Facilities and Infrastructure ..................................................................................... 17-9
17.4.4 Environment ......................................................................................................................... 17-9
17.4.5 Economic Impact .................................................................................................................. 17-9
17.5 Future Trends in Development .................................................................................... 17-10
17.6 Issues ............................................................................................................................ 17-10
18. Wildfire ...................................................................................................................... 18-1
18.1 Overview ........................................................................................................................ 18-1
18.1.1 Wildfire Protection Responsibility Areas .............................................................................. 18-1
18.1.2 Fire Protection Distircts and Agencies ................................................................................. 18-3
18.1.3 The Fire Equation ................................................................................................................. 18-7
18.1.4 Development Patterns and Wildfire Hazard ........................................................................ 18-9
18.2 Hazard Profile............................................................................................................... 18-10
18.2.1 History ................................................................................................................................ 18-10
18. 2.2 Location .............................................................................................................................. 18-13
18.2.3 Frequency ........................................................................................................................... 18-14
18.2.4 Severity ............................................................................................................................... 18-15
18.2.5 Warning Time ..................................................................................................................... 18-17
18.3 Secondary Hazards ....................................................................................................... 18-17
18.3.1 Wildfire Smoke ................................................................................................................... 18-17
18.3.2 Post-Fire Induced Debris Flows and Flood Flows ............................................................... 18-18
18.4 Risk Assessment ........................................................................................................... 18-18
18.4.1 Population .......................................................................................................................... 18-20
18.4.2 Property .............................................................................................................................. 18-21
18.4.3 Critical Facilities and Infrastructure ................................................................................... 18-21
18.4.4 Environment ....................................................................................................................... 18-23
18.4.5 Economic Impact ................................................................................................................ 18-23
18.5 Future Trends in Development .................................................................................... 18-24
18.6 Issues ............................................................................................................................ 18-24
19. Climate Change ........................................................................................................... 19-1
19.1 Overview ........................................................................................................................ 19-1
19.1.1 Sea Level Rise ....................................................................................................................... 19-2 COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan
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19.1.2 Climate Change and Hazard Mitigation................................................................................ 19-2
19.2 Hazard Profile................................................................................................................. 19-4
19.2.1 History .................................................................................................................................. 19-4
19.2.2 Location ................................................................................................................................ 19-5
19.2.3 Frequency ............................................................................................................................. 19-5
19.2.4 Severity ................................................................................................................................. 19-5
19.2.5 Warning Time ....................................................................................................................... 19-9
19.3 Responses to Climate Change ........................................................................................ 19-9
19.3.1 Community Resilience ........................................................................................................ 19-10
19.4 Risk Assessment- Sea Level Rise .................................................................................. 19-12
19.4.1 Population and Property .................................................................................................... 19-15
19.4.2 Critical Facilities and Infrastructure ................................................................................... 19-16
19.4.3 Environment ....................................................................................................................... 19-17
19.4.4 Economic Impact ................................................................................................................ 19-18
19.5 Risk Assessment- Hazards of Concern ......................................................................... 19-19
19.5.1 Agricultural Emergencies.................................................................................................... 19-19
19.5.2 Coastal Erosion ................................................................................................................... 19-20
19.5.3 Dam and Levee Failure ....................................................................................................... 19-21
19.5.4 Drought .............................................................................................................................. 19-21
19.5.5 Earthquake ......................................................................................................................... 19-22
19.5.6 Flooding .............................................................................................................................. 19-22
19.5.7 Human Caused Hazards ...................................................................................................... 19-23
19.5.8 Public Health Hazards ......................................................................................................... 19-23
19.5.9 Severe Weather .................................................................................................................. 19-25
19.5.10 Slope Failure ..................................................................................................................... 19-25
19.5.11 Tsunami ............................................................................................................................ 19-25
19.5.12 Wildfire ................................ ............................................................................................. 19-25
19.6 Issues ............................................................................................................................ 19-26 Part C: Mitigation Capability and Strategy .............................................................................. C
20. Capability Assessment ................................................................................................ 20-1
20.1 Incorporation of Existing Plans, Studies, Reports, and Technical Information ............. 20-2
20.1.1 Federal .................................................................................................................................. 20-2
20.1.2 State ..................................................................................................................................... 20-9
20.2 Local Capability Assessment ........................................................................................ 20-16
20.3 Safe Growth Survey ..................................................................................................... 20-17
20.4 NFIP Survey .................................................................................................................. 20-18
20.5 Capability Assessment Survey ..................................................................................... 20-20
21. Mitigation Strategy ..................................................................................................... 21-1
21.1 Guiding Principle ............................................................................................................ 21-1
21.2 Mitigation Goals ............................................................................................................. 21-2
21.3 Identification of Mitigation Actions ............................................................................... 21-3
21.4 Mitigation Action Prioritization ..................................................................................... 21-4
21.4.1 Mitigation Alternatives ......................................................................................................... 21-6
21.5 Hazard Prioritization ...................................................................................................... 21-6
21.5.1 Countywide Problem Statements ........................................................................................ 21-6 COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan
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21.6 Mitigation Action Plan ................................................................................................... 21-9
21.6.1 Countywide Mitigation Action Plan.................................................................................... 21-10
22. Plan Implementation and Maintenance ...................................................................... 22-1
22.1 Plan Adoption ................................................................................................................ 22-1
22.2 Plan Maintenance .......................................................................................................... 22-1
22.2.1 Plan Implementation ............................................................................................................ 22-2
22.2.2 Incorporation into Other Planning Mechanisms .................................................................. 22-3
22.2.3 Plan Monitoring and Evaluation ........................................................................................... 22-4
22.2.4 Plan Update .......................................................................................................................... 22-5
22.2.5 Continued Public Involvement ............................................................................................. 22-6
Appendix 1: Plan Adoption Resolutions from Planning Partners Appendix 2: Plan Progress Report Template
Appendix 3: Steering Committee Meeting Agendas
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TABLES AND FIGURES
Table 2-1: MJHMP Planning Timeline .......................................................................................... 2-2 Table 2-2: 2022 MJHMP Steering Committee Members ............................................................. 2-3 Table 2-3: Steering Committee Meeting Schedule ...................................................................... 2-4 Table 2-4: Jurisdiction-Specific Planning Meetings ..................................................................... 2-7 Table 2-5: Public Survey Respondents by Location ................................................................... 2-10 Table 2-6: Hazard Mitigation Community Forums on the 2022 MJHMP .................................. 2-12 Table 2-7: Community Forums Interactive Activity Results: Community Assets ...................... 2-13 Table 2-8: Community Forums Interactive Activity Results: Hazard Concern ........................... 2-14 Table 2-9: Public Presentations on the 2022 MJHMP Update .................................................. 2-14 Table 2-10: Jurisdiction Plan Adoption Dates ............................................................................ 2-17 Table 3-1: Total Land Area and Population in Monterey County ................................................ 3-8 Table 3-2: Home Ownership in Monterey County Compared to Other Jurisdictions ............... 3-12 Table 3-3: Projected Change in Occupation in Monterey County ............................................. 3-16 Table 3-4: Percent of Noninstitutionalized County Residents with a Disability by Age ............ 3-20 Table 3-5: Prevalence of Chronic Health Conditions of Adults Aged 18 and Over .................... 3-20 Table 3-6: Land Cover in Monterey County 2018 Statistics....................................................... 3-23 Table 4-1: Hazards of Concern ..................................................................................................... 4-2 Table 4-2: Excluded Hazards ........................................................................................................ 4-6 Table 4-3: Disaster Proclamations and Declarations (1990-2021) .............................................. 4-8 Table 4-4: Monterey County Parcel and Population Inventory ................................................. 4-15 Table 4-5: Critical Infrastructure and Assets Data Sources ....................................................... 4-16 Table 4-6: Hazard Exposure Data ............................................................................................... 4-17 Table 4-7: Degree of Risk Scores ................................................................................................ 4-22 Table 4-8: Number of Participating Jurisdictions Assigning A Given Ranking to a Hazard ........ 4-23 Table 4-9: Countywide Threat Hazard Identification and Risk Assessment .............................. 4-24 Table 4-10: Countywide Hazard Risk Ranking ........................................................................... 4-25 Table 5-1:USDA Agricultural Disaster Designations in Monterey County (2012-2021) .............. 5-4 Table 5-2: Gross Production Value of Crops in Monterey County .............................................. 5-8 Table 5-3: Value of Agricultural Land in Monterey County ......................................................... 5-9 Table 5-4: Prime Farmland Exposed to Wildfire Risk by Fire Hazard Severity Zone ................. 5-10 Table 5-5: Farmland of Statewide Importance Exposed to Wildfire Risk .................................. 5-10 Table 5-6: Unique Farmland Exposed to Wildfire Risk by Fire Hazard Severity Zone ............... 5-10 Table 5-7: Grazing Land Exposed to Wildfire Risk by Fire Hazard Severity Zone ...................... 5-11 Table 5-8: Prime Farmland Exposed to Flood Hazard Risk ........................................................ 5-11 Table 5-9: Farmland of Statewide Importance Exposed to Flood Hazard Risk ......................... 5-11 Table 5-10: Unique Farmland Exposed to Flood Hazard Risk .................................................... 5-12 Table 5-11: Grazing Land Exposed to Flood Hazard Risk ........................................................... 5-12 COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan
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Table 6-1: Estimated Historic Average Erosion Rates in Southern Monterey Bay ...................... 6-4 Table 6-2: Population Exposed to Coastal Cliff Erosion in Monterey County ............................. 6-7 Table 6-3: Population Exposed to Shoreline Erosion Risk in Monterey County .......................... 6-7 Table 6-4: Residential Property Exposed to Coastal Cliff Erosion Risk ........................................ 6-8 Table 6-5: Residential Property Exposed to Shoreline Erosion Risk ............................................ 6-8 Table 6-6: Non-Residential Property Exposed to Coastal Cliff Erosion Risk ................................ 6-8 Table 6-7: Non-Residential Property Exposed to Shoreline Erosion Risk .................................... 6-9 Table 6-8: Transportation Infrastructure Exposed to Cliff and Shoreline Erosion Risk ............... 6-9 Table 7-1: Dams in or Owned by Monterey County .................................................................... 7-5 Table 7-2: Miles of Levee in Monterey County by Waterbody .................................................... 7-7 Table 7-3: US Army Corps of Engineers Dam Hazard Potential Classification ........................... 7-14 Table 7-4: Population Exposed to Dam Failure- Nacimiento Dam ............................................ 7-16 Table 7-5: Population Exposed to Dam Failure- San Antonio Dam ........................................... 7-17 Table 7-6: Population Exposed to Dam Failure- Forest Lake Dam ............................................ 7-17 Table 7-7: Population Exposed to Levee Failure by Waterbody ................................................ 7-18 Table 7-8: Residential Property Exposed to Dam Failure- Nacimiento Dam ............................. 7-18 Table 7-9: Non-Residential Property Exposed to Dam Failure- Nacimiento Dam ..................... 7-19 Table 7-10: Residential Property Exposed to Dam Failure- San Antonio Dam .......................... 7-19 Table 7-11: Non-Residential Property Exposed to Dam Failure- San Antonio .......................... 7-19 Table 7-12: Residential Property Exposed to Dam Failure- Forest Lake Dam ........................... 7-20 Table 7-13: Non-Residential Property Exposed to Dam Failure- Forest Lake Dam ................... 7-20 Table 7-14: Property Exposed to Levee Failure by Waterbody ................................................. 7-20 Table 7-15: Critical Infrastructure Exposed to Dam Failure Risk ............................................... 7-21 Table 8-1: Drought Impacts by USDM Drought Category in California ....................................... 8-3 Table 8-2: State Drought Management Program ........................................................................ 8-4 Table 8-3: USDA Agricultural Disaster Designations in Monterey County (2012-2021) ............. 8-7 Table 9-1: Earthquake Magnitude Classes (Moment Magnitude Scale) ..................................... 9-4 Table 9-2: Modified Mercalli Intensity Level Descriptions .......................................................... 9-5 Table 9-3: Modified Mercalli Scale and Peak Ground Acceleration ............................................ 9-6 Table 9-4: NEHRP Soil Classification System ................................................................................ 9-7 Table 9-5: Monterey County Earthquakes, Magnitude 6.0+ (1838-Present) .............................. 9-8 Table 9-6: Population Exposed to Areas Susceptible to Liquefaction ....................................... 9-17 Table 9-7: Residential Property Exposed to Areas Susceptible to Liquefaction ........................ 9-18 Table 9-8: Non-Residential Property Exposed to Areas Susceptible to Liquefaction ................ 9-18 Table 9-9: Critical Infrastructure in High Liquefaction Susceptibility Areas .............................. 9-20 Table 10-1: NFIP Coverage ......................................................................................................... 10-3 Table 10-2: FEMA Flood Zones .................................................................................................. 10-4 Table 10-3: Community Ratings System (CRS) Participation ..................................................... 10-5 Table 10-4: NFIP Loss Statistics for Monterey County ............................................................. 10-15 Table 10-5: Residential Property Exposed to Flood Risk by Flood Zone ................................. 10-18 Table 10-6: Non-Residential Property Exposed to Flood Risk by Flood Zone ......................... 10-18 COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan
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Table 10-7: Critical Infrastructure in the 100-Year Floodplain ................................................ 10-19 Table 11-1: Hazardous Materials Spills by Spill Site and Substance Spilled (2016-2021) ......... 11-4 Table 11-2: Hazardous Materials Spills by Cause of Spill (2016-2021) ...................................... 11-4 Table 11-3: Population Exposed to Hazardous Materials Incident Risk .................................... 11-8 Table 11-4: Residential Property Exposed to Hazardous Materials Incident Risk ..................... 11-9 Table 11-5: Non-Residential Property Exposed to Hazardous Materials Incident Risk ............. 11-9 Table 11-6: Critical Infrastructure Exposed to Hazardous Materials Incident Risk ................. 11-10 Table 12-1: Event Profiles for Terrorism .................................................................................... 12-4 Table 13-1: Selected Communicable Disease Cases in Monterey County (2009-2019) .......... 13-12 Table 13-2: Severe Influenza Cases (Age 64 and Younger) By Flu Season............................... 13-12 Table 13-3: COVID-19 Cases Among County Residents by Age Group .................................... 13-15 Table 13-4: Severe COVID-19 Cases Among Residents by Age Group .................................... 13-16 Table 13-5: COVID-19 Fatalities Among Residents by Age Group ........................................... 13-17 Table 14-1: Severe Winter Storms and Extreme Freeze Events (2010-2020) ........................... 14-6 Table 14-2: Annualized Frequency of Severe Weather Events in Monterey County .............. 14-12 Table 14-3: NWS Experimental HeatRisk Forecast Risk Levels ................................................ 14-13 Table 14-4: Population Exposed to Severe Weather Hazards in Monterey County ............... 14-15 Table 14-5: Exposed and Expected Annual Loss of Building Value to Severe Weather .......... 14-15 Table 15-1: Historic Large Landslides Along Highway 1 on the Big Sur Coast ........................... 15-5 Table 15-2: Population Exposed to Earthquake Induced Landslide Risk ................................. 15-12 Table 15-3: Residential Property Exposed to Earthquake Induced Landslide Risk.................. 15-13 Table 15-4: Non-Residential Property Exposed to Earthquake Induced Landslide Risk ......... 15-13 Table 15-5: Critical Infrastructure Exposed to Earthquake Induced Landslide Risk ................ 15-14 Table 16-1: Historic Monterey County Tsunami Events ............................................................ 16-4 Table 16-2: Tsunami Source Scenario Model Results- North County ........................................ 16-5 Table 16-3: Tsunami Source Scenario Model Results- Monterey.............................................. 16-6 Table 16-4: Tsunami Source Scenario Model Results- South County ........................................ 16-6 Table 16-5: Population in Tsunami Inundation Zone .............................................................. 16-10 Table 16-6: Residential Property in Tsunami Inundation Zone ............................................... 16-11 Table 16-7: Non-Residential Property in Tsunami Inundation Zone ....................................... 16-11 Table 16-8: Critical Infrastructure in Tsunami Inundation Zone in Monterey County ............ 16-12 Table 17-1: FEMA Standard Values for Loss of Services for Utilities and Roads/Bridges ......... 17-9 Table 18-1: Fire Protection Districts in Monterey County ......................................................... 18-4 Table 18-2: Large Historical Wildfires in Monterey County (1977-2020) ................................ 18-11 Table 18-3: Residential Property Exposed to Wildfire Risk by Fire Hazard Threat Zone ......... 18-21 Table 18-4: Non-Residential Property Exposed to Wildfire Risk by Fire Hazard Threat Zone. 18-21 Table 18-5: Critical Infrastructure Exposed to Wildfire Risk by Fire Hazard Threat Zone ....... 18-22 Table 19-1: Predicted Change in Annual Average Temperatures in Monterey County ............ 19-7 Table 19-2: Monterey Tide Gauge Projected Sea Level Rise (in Feet) ..................................... 19-13 Table 19-3: Population and Property Exposed to Sea Level Rise Risk in District 2 .................. 19-15 Table 19-4: Population and Property Exposed to Sea Level Rise Risk in District 4 .................. 19-15 COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan
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Table 19-5: Population and Property Exposed to Sea Level Rise Risk in District 5 .................. 19-15 Table 19-6: Critical Infrastructure Exposed to Sea Level Rise Risk .......................................... 19-16 Table 19-7: Population and Property Exposed to Coastal Erosion Risk ................................... 19-20 Table 20-1: Countywide Safe Growth Survey Results ............................................................. 20-18 Table 20-2: NFIP Participation ................................................................................................. 20-20 Table 20-3: Capability Assessment Survey- Documents and Resources Assessed .................. 20-22 Table 20-4: Jurisdictions Participating in Various Community Mitigation Programs .............. 20-23 Table 20-5: Participating Jurisdictions Self-Assessment of Capability Ratings ........................ 20-24 Table 21-1: High and Substantial Hazards from Countywide Risk Prioritization ....................... 21-6 Table 21-2: Countywide Mitigation Action Plan ...................................................................... 21-10
Figure 2-1: Survey Responses to Date ....................................................................................... 2-10 Figure 2-2: Heat Map of Public Survey Respondents ................................................................ 2-11 Figure 3-1: Map of Monterey County .......................................................................................... 3-2 Figure 3-2: Monterey County Demographics .............................................................................. 3-9 Figure 3-3: Monterey County Labor Force Breakdown, By Industry ......................................... 3-14 Figure 3-4: Inflow/ Outflow Job Counts in 2018 for Monterey County ..................................... 3-15 Figure 3-5: Overall Social Vulnerability Index in Monterey County .......................................... 3-17 Figure 3-6: CDC Social Vulnerability Index: Socioeconomic Status ........................................... 3-18 Figure 3-7: CDC Social Vulnerability Index: Household Composition and Disability ................. 3-19 Figure 3-8: CDC Social Vulnerability Index: Minority Status and Language .............................. 3-21 Figure 3-9: CDC Social Vulnerability Index: Housing and Transportation ................................. 3-22 Figure 4-1: Historical Declared Hazard Events by Hazard Type (1990-2021) ............................ 4-10 Figure 4-2: 2010 Monterey County Supervisorial Districts ........................................................ 4-13 Figure 4-3: Risk Ranking Score Matrix by Variable .................................................................... 4-22 Figure 5-1: Important Farmland in Monterey County ................................................................. 5-6 Figure 7-1: Nacimiento Dam Failure Inundation Zone .............................................................. 7-10 Figure 7-2: San Antonio Dam Failure Inundation Zone ............................................................. 7-11 Figure 7-3: Los Padres and Forest Lake Dam Failure Inundation Zones .................................... 7-12 Figure 7-4: Levees in Monterey County ..................................................................................... 7-13 Figure 8-1: US Drought Monitor, Drought Conditions as of August 17, 2021 ............................. 8-6 Figure 8-2: Monterey County Percentage Area Drought Conditions .......................................... 8-9 Figure 9-1: Known Faults in Monterey County by Age ................................................................ 9-3 Figure 9-2: Known Faults in Monterey County by Slip Rate ...................................................... 9-10 Figure 9-3: NEHRP Soil Classes in Monterey County ................................................................. 9-11 Figure 9-4: Earthquake Shaking Potential ................................................................................. 9-13 Figure 9-5: Liquefaction Susceptibility in Monterey County ..................................................... 9-14 Figure 9-6: ShakeAlert Earthquake Early Warning Basics .......................................................... 9-15 Figure 10-1: Watersheds in Monterey County .......................................................................... 10-7 Figure 10-2: FEMA Flood Zones ............................................................................................... 10-13 Figure 10-3: DWR Flood Awareness Zones .............................................................................. 10-14 COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan
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Figure 10-4:Population Exposed to Flood Risk ........................................................................ 10-17 Figure 12-1: Monterey County Attractions Visited .................................................................. 12-13 Figure 12-2: Monterey County Areas Visited .......................................................................... 12-13 Figure 13-1: COVID-19 Cases Among Monterey County Residents by Date ........................... 13-15 Figure 13-2: COVID-19 Cases Among Monterey County Residents by Region of Residence .. 13-16 Figure 14-1: National Weather Service Heat Index ................................................................... 14-5 Figure 14-2: 30-Year Average Annual Precipitation in Monterey County ................................. 14-8 Figure 14-3: 30-Year Average Minimum Temperatures in Monterey County .......................... 14-9 Figure 14-4: Land-Based Wind Speed (Meters/Second).......................................................... 14-10 Figure 14-5: 30-Year Average Maximum Temperatures in Monterey County ........................ 14-11 Figure 15-1: Deep-Seated Landsilde Susceptibility in Monterey County .................................. 15-8 Figure 15-2: Earthquake Induced Landslide Susceptibility ........................................................ 15-9 Figure 16-1: Tsunami Hazard Areas in Monterey County .......................................................... 16-8 Figure 17-1: NOAA Space Weather Scales ................................................................................. 17-5 Figure 18-1: Fire Protection Responsibility Areas in Monterey County .................................... 18-3 Figure 18-2: Fire Protection Districts in Monterey County........................................................ 18-7 Figure 18-3: Historical Wildfires in Monterey County (1911-2020) ........................................ 18-10 Figure 18-4: Causes of Wildfires in Monterey County (2000-2020) ........................................ 18-12 Figure 18-5: Fire Hazard Severity Zones in Monterey County ................................................. 18-13 Figure 18-6: Fire Frequency in Monterey County .................................................................... 18-15 Figure 18-7: Wildland Fire Threat ............................................................................................ 18-19 Figure 18-8: Population Exposed to Wildfire Risk ................................................................... 18-20 Figure 19-1: Projected Increase in Average Temperature in Monterey County ....................... 19-7 Figure 19-2: Projected Increase in Extreme Heat Days in Monterey County ............................ 19-8 Figure 19-3: Sea Level Rise Risk ............................................................................................... 19-14 Figure 19-4: 1.6 Feet Sea Level Rise in Moss Landing with Various Storm Scenarios ............. 19-16
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JURISDICTIONAL ANNEXES
While this Volume, Volume 1, address the entire geographic area of Monterey County and all participating jurisdictions holistically, Volume 2 of the Monterey County Multi-Jurisdictional Hazard Mitigation Plan contains the Jurisdictional Annexes for each participating jurisdiction.
A Unincorporated County of Monterey (and Monterey County Water Resources Agency) B City of Carmel-by-the-Sea
C City of Del Rey Oaks
D City of Gonzales
E City of Greenfield
F City of King
G City of Marina
H City of Monterey
I City of Pacific Grove
J City of Salinas
K City of Sand City
L City of Seaside
M City of Soledad
N Carmel Area Wastewater District
O Monterey One Water
P Monterey Regional Waste Management District
Q Moss Landing Harbor District
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ACRONYMS AND ABBREVIATIONS
AB Assembly Bill
AMBAG Association of Monterey Bay Area Governments
APG Adaptation Planning Guide
APN Assessor Parcel Numbers
BFE Base Flood Elevation
BRIC Building Resilient Infrastructure and Communities
CAL FIRE California Department of Forestry and Fire Protection Cal OES California Governor’s Office of Emergency Services Cal-Am Water California-American Water Company
CalARP California Accidental Release Prevention Program Caltrans California Department of Transportation
CAWD Carmel Area Wastewater District
CCR California Code of Regulations
CDAA California Disaster Assistance Act
CDBG Community Development Block Grant
CDC Centers for Disease Control and Prevention
CDFW California Department of Fish and Wildlife
CDPH California Department of Public Health
CEQA California Environmental Quality Act
CERV Community Emergency Response Volunteers
CFR Code of Federal Regulations
CGS California Geological Survey
CHP California Highway Patrol
CIP Capital Improvement Plan
CoSMoS USGS Coastal Storm Modeling System
County Monterey County
COVID-19 Coronavirus Disease 2019
CRS Community Rating System
CSUMB California State University, Monterey Bay
DFIRM Digital Flood Insurance Rate Map
DHS Department of Homeland Security
DMA Disaster Mitigation Act of 2000
DSOD California Division of Safety of Dams
DTSC Department of Toxic Substances Control
DWR California Department of Water Resources
EEW Earthquake Early Warning
EOP Emergency Operations Plan
EPA US Environmental Protection Agency
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ACRONYMS AND ABBREVIATIONS
ESA Endangered Species Act
FEMA Federal Emergency Management Agency
FERC Federal Energy Regulatory Commission
FHSZ Fire Hazard Severity Zones
FIRM Flood Insurance Rate Map
FIS Flood Insurance Study
FMA Flood Mitigation Assistance Program
FMAG Fire Management Assistance Grant
FMMP Farmland Mapping and Monitoring Program
FPD Fire Protection District
FRA Federal Responsibility Area
FRAP Fire and Resource Assessment Program
GIS Geographic Information System
HHPD High Hazard Potential Dams
HMA Hazard Mitigation Assistance
HMGP Hazard Mitigation Grant Program
IBC International Building Code
JPA Joint Powers Authority
LHMP Local Hazard Mitigation Plan
LRA Local Responsibility Area
M1W Monterey One Water
MBARI Monterey Bay Aquarium Research Institute
MBNMS Monterey Bay National Marine Sanctuary
MCI Multiple Casualty Incident
MCOE Monterey County Office of Education
MCWRA Monterey County Water Resources Agency
MHHW Mean Higher High Water
MJHMP Multi-Jurisdictional Hazard Mitigation Plan
MM Modified Mercalli Scale
MPRPD Monterey Peninsula Regional Park District
MPWMD Monterey Peninsula Water Management District
MRWMD Monterey Regional Waste Management District
MST Monterey-Salinas Transit
NCRIC Northern California Regional Intelligence Center
NEHRP National Earthquake Hazards Reduction Program
NEPA National Environmental Policy Act
NFIP National Flood Insurance Program
NIMS National Incident Management System
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ACRONYMS AND ABBREVIATIONS
NOAA National Oceanic and Atmospheric Administration
NPS National Park Service
NRCS Natural Resources Conservation Service
NTWC National Tsunami Warning Center
NWS National Weather Service
OES Monterey County Office of Emergency Services
OPC Ocean Protection Council
OPR Governor's Office of Planning and Research
PBCSD Pebble Beach Community Services District
PG&E Pacific Gas and Electric
PGA Peak Ground Acceleration
PHMSA Pipeline and Hazardous Materials Safety Administration PSPS Public Safety Power Shut-off
RCDMC Resources Conservation District of Monterey County RCP Representative Concentration Pathways
RL Repetitive Loss
RWQCB Regional Water Quality Control Boards
SARS Severe Acute Respiratory Syndrome
SB Senate Bill
SBA Small Business Administration
SFHA Special Flood Hazard Area
SGMA Sustainable Groundwater Management Act
SHMP State Hazard Mitigation Plan
SRA State Responsibility Area
Stafford Act Robert T. Stafford Disaster Relief and Emergency Assistance Act Steering Committee Multi-Jurisdictional Hazard Mitigation Steering Committee UBC Uniform Building Code
URM Unreinforced Masonry
USACE US Army Corps of Engineers
USDA US Department of Agriculture
USFS US Forest Service
USGS US Geological Survey
WHO World Health Organization
WMD Weapons of Mass Destruction
WUI Wildland Urban Interface
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EXECUTIVE SUMMARY
HAZARD MITIGATION OVERVIEW
Monterey County is vulnerable to a wide range of natural and manmade hazards. These hazards can threaten the life and safety of residents and visitors and have the potential to damage or destroy both public and private property and disrupt the local economy and overall quality of life. While the threats from hazard events may never be fully eliminated, there is much we can do to lessen their potential impact on our communities. By minimizing the damaging impacts of hazards upon our built environment, we can prevent such events from resulting in disasters.
The concept and practice of reducing risks to people and property from known hazards is called hazard mitigation.
Hazard mitigation is the use of long-term and short-term policies, programs, projects, and other activities to alleviate the death, injury, and property damage that can result from a disaster.
Monterey County and a partnership of local governments within the County have developed a hazard mitigation plan to reduce risks from natural disasters in the Monterey County Operational Area—defined as the unincorporated county and incorporated jurisdictions within the geographical boundaries of the County. The plan complies with federal and state hazard mitigation planning requirements to establish eligibility for funding under Federal Emergency Management Agency (FEMA) grant programs.
UPDATING THE MONTEREY COUNTY PLAN
This plan is a comprehensive update of the 2016 Monterey County Multi-Jurisdictional Hazard Mitigation Plan, which covered the unincorporated county, 12 municipalities and 2 special purpose districts. FEMA approved the 2016 plan on March 7, 2016, and it expired on March 7, 2021, the current update meets federal requirements for updating hazard mitigation plans on a five-year cycle. It represents the third iteration of the Monterey County Multi-Jurisdictional Hazard Mitigation Plan, which was initially adopted in 2007.
This Plan was prepared in coordination with
FEMA and the California Office of Emergency
Services (Cal OES) to ensure that it meets all
applicable federal and state requirements.
This includes conformance with FEMA’s
latest Local Mitigation Planning Handbook
(released March 2013) and Local Mitigation
Plan Review Guide (released October 2011).
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GUIDING PRINCIPLE
The following guiding principle was created and agreed upon by the participants to represent the overall intended outcome of the Plan:
Reduce the risk to life and property in Monterey County in an efficient and effective manner by decreasing the long-term vulnerability from hazards through coordinated planning, partnerships, capacity building, and implementation of effective risk reduction measures.
SCOPE AND AUTHORITY
The Monterey County Multi-Jurisdictional Hazard Mitigation Plan geographically covers the entire area of Monterey County and has multiple participating jurisdictions. This includes Monterey County, 12 incorporated municipalities, and 5 special districts, hereinafter referred to as “participating jurisdictions.”
• Unincorporated Monterey County
• Monterey County Water Resources Agency (MCWRA) (Included with unincorporated Monterey County)
• City of Carmel-by-the-Sea
• City of Del Rey Oaks
• City of Gonzales
• City of Greenfield
• City of King
• City of Marina
• City of Monterey
• City of Pacific Grove
• City of Salinas
• City of Sand City
• City of Seaside
• City of Soledad
• Carmel Area Wastewater District (CAWD)
• Monterey Regional Waste Management District (MRWMD)
• Monterey One Water (M1W)
• Moss Landing Harbor District
Representatives from each participating jurisdiction formed a core planning team, referred to as the Steering Committee, in order to drive the development of the plan update. The Steering Committee was at the core of the MJHMP planning process and was integral to ensuring its success, its implementation, and its future maintenance. The Plan addresses those hazards determined to be of primary or secondary concern to each jurisdiction, as documented in the risk assessment portion of this Plan. Other hazards that pose a low risk or are otherwise COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan
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omitted from this Plan will continue to be evaluated during future plan updates, but they may not be fully addressed until they are determined to be of primary or secondary concern to Monterey County. Individual entities are still able to, and are encouraged to, continue to address, and plan for those other hazards as may be appropriate within their jurisdictions.
This Plan must be adopted by all participating jurisdictions in accordance with the authority and police powers granted to local governments under Article 11 of the California Constitution. This Plan was developed in accordance with current federal rules and regulations governing local hazard mitigation plans. The Plan shall be monitored and updated on a routine basis to maintain compliance with the following legislation: Section 322, Mitigation Planning, of the Robert T. Stafford Disaster Relief and Emergency Assistance Act, as enacted by Section 104 of the Disaster Mitigation Act of 2000 (Public Law 106-390) and by FEMA's Interim Final Rule published in the Federal Register on February 26, 2002, at 44 CFR Part 201.
PLAN STRUCTURE
This plan has been set up in two volumes so that elements that are jurisdiction-specific can easily be distinguished from those that apply to the whole County.
Volume 1 includes the federally required elements of a hazard mitigation plan for all participating jurisdictions. This includes the description of the planning process, public involvement strategy, hazard risk assessments, countywide mitigation actions, and a plan maintenance strategy. Since this is a multi-jurisdictional plan, Volume 1 addresses the entirety of Monterey County, which includes all participating jurisdictions and the entire geographic boundary of the County.
Volume 2 contains the Jurisdictional Annexes, which detail the hazard mitigation planning elements specific to each participating jurisdiction in the Monterey County MJHMP Update and includes all federally required jurisdiction-specific elements for each participating jurisdiction.
Each annex is not intended to be a standalone document, but annexes to, supplements, and incorporates by reference the information contained in Volume 1 of the Plan. As such, all information in Volume 1, including the planning process and other procedural requirements and planning elements apply to and were met by each participating jurisdiction. The Annexes provide additional information specific to each participating jurisdiction, with a focus on providing additional details on the risk assessment and mitigation strategy.
All participating jurisdictions will adopt Volume 1 in its entirety and their own jurisdiction- specific annex in Volume 2.
RISK ASSESSMENT
Risk assessment is the process of measuring the potential loss of life resulting from natural hazards, as well as personal injury, economic injury, and property damage, in order to COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan
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determine the vulnerability of people, buildings, infrastructure, and the environment to natural hazards. For this update, risk assessment models were enhanced with new data and technologies that have become available since 2016. The Steering Committee used the risk assessment to rank risk and to gauge the potential impacts of each hazard of concern in the Operational Area. The risk assessment included the following:
• Hazard identification and profiling
• Assessment of the impacts on physical, social, environmental, and economic assets • Identification of particular areas of vulnerability
• Estimates of the cost of potential damage.
Based on the risk assessment, hazards were ranked for the risk they pose to the overall Operational Area.
Ranking Hazard Degree of Risk
1 Drought & Water Shortage High
2 Earthquake Substantial
3 Pandemic Substantial
4 Wildfire Substantial
5 Epidemic Substantial
6 Cyber-Attack Substantial
7 Utility Interruption/ PSPS Substantial
8 Localized Stormwater Flooding Substantial
9 Severe Winter Storms Substantial
10 Water Contamination Moderate
11 Windstorms Moderate
12 Hazardous Materials Incident Moderate
13 Agricultural Emergencies Moderate
14 Riverine Flooding Moderate
15 Sea Level Rise Moderate
16 Slope Failure Moderate
17 Flash Flood Moderate
18 Extreme Heat Moderate
19 Coastal Flooding Moderate
20 Coastal Erosion Moderate
21 Targeted Violence Possible
22 Invasive Species Possible
23 Terrorism Possible
24 Dam Failure Possible
25 Extreme Cold & Freeze Possible
26 Mass Migration Possible
27 Tsunami Possible
28 Levee Failure Possible
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MITIGATION GOALS
The Steering Committee reviewed and updated the goals from the 2016 Monterey County Multi-Jurisdictional Hazard Mitigation Plan and confirmed a set of goals. The Steering Committee and planning partners established the following goals for the plan update:
Goal #1 Minimize risk and vulnerability of Monterey County to hazards and protect lives and prevent losses to property, public health, economy, and the environment.
Goal #2
Increase the resilience of infrastructure and critical facilities and reduce long-term vulnerabilities of existing and future critical facilities, property, infrastructure, and high hazard potential dams due to natural hazards.
Goal #3 Build and support capacity to enable local government and the public to prepare for, respond to, and recover from the impact of natural hazards.
Goal #4 Encourage the development and implementation of long-term, cost-effective, and environmentally sound mitigation projects.
Goal #5 Promote and implement hazard mitigation policies and projects that are consistent with state, regional, and local climate action, and adaptation goals.
Goal #6 Inform the public on the risk from hazards of concern and increase awareness, preparation, mitigation, response, and recovery activities to promote public safety.
Goal #7
Enhance codes and their enforcement where feasible, so that new construction can withstand the impacts of known hazards and to lessen the impact of development on the environment’s ability to absorb the impact of natural hazards.
Goal #8 Consider the impacts of known hazards in all planning mechanisms that address current and future land uses within the County.
Goal #9 Establish a partnership among all levels of government and the business community to improve and implement methods to protect property.
Goal #10 Encourage hazard mitigation measures that promote and enhance natural processes and minimize adverse impacts on the ecosystem.
HAZARD PROBLEM STATEMENTS
As part of the planning process, the Steering Committee and planning partners identified key vulnerabilities and hazards of concerns applicable to the entire County. Hazard Problem Statements helped the Steering Committee identify common issues and weaknesses, determine appropriate mitigation strategies, and understand the realm of resources needed for mitigation. The update process resulted in the identification of unique hazard problem statements by individual planning partners, as presented in Volume 2 of this plan.
In addition, the Steering Committee and planning partners identified countywide problem statements. The Countywide Hazard Problem Statements were based on the risk assessments, COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan
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the risk prioritization process, the vulnerability analysis, and local knowledge, as well as the jurisdiction specific problem statements and community and stakeholder input.
Countywide Hazard Problem Statements are identified below:
Drought & Water Shortage
In Monterey County, water supply is extremely limited during non-drought years. As such, droughts are a serious threat in the County and could have devastating impacts on the agricultural industry, a major economic driver and job provider. Additionally, prolonged periods of drought can reduce water available for residential users and increase water prices.
Governing authorities have been established to limit water use and protect water supply.
Procurement of water credits/rights may limit new development necessary to meet increasing housing demands. Periods of drought also lead to increased pumping of groundwater wells, which can exacerbate sea water intrusion into the aquifer, increase land subsidence risks, and effect water quality. Contamination of drinking water, though unlikely, could be catastrophic.
Drought conditions are likely to increase in future climate change scenarios.
Earthquake
Monterey County has several fault systems, including three major active faults: The San Andreas Fault, the Palo Colorado-San Gregorio Fault, and the Monterey Bay-Tularcitos Fault.
Due to the location of population centers and building history in the County, any large earthquake will likely have significant impacts on people, property, and critical infrastructure including water systems, telecommunications infrastructure, roads, bridges, healthcare systems, and utilities. Damages and debris could isolate large populations from these critical lifelines. Older unreinforced-masonry structures in the County are particularly vulnerable to earthquake risk. An earthquake can also produce cascading impacts due to urban conflagration, wildfires, seiches, landslides, tsunamis, dam failure, and levee failure.
Pandemic/ Epidemic
The whole population of Monterey County is vulnerable to disease. The impacts of the COVID- 19 Pandemic on the County have demonstrated the catastrophic risks that can be associated with large-scale disease outbreaks. Critical healthcare systems can become overwhelmed, limiting access to life-saving medical services. Continuity of government due to impacted workforces can result in limitations to essential government services. Disease outbreaks can place a disproportionate burden on the County’s most vulnerable populations. Additionally, due to the large number of transient populations, such as tourists and migrant farmworkers, eradication of any new disease outbreak can be difficult without significant impacts to industry and the local economy.
Wildfire
California, and subsequently Monterey County, is in cycle of extreme heat, drought, and fire, all amplified by climate change. Wildfires are a natural part of the California environment; however, fire behavior has increased in frequency, size, and impact from longer wildfire COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan
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“seasons.” Deferred vegetation management and population sprawl in the wildland urban interface and intermix, have increased probability and impact of wildfires. Sudden oak death and invasive species have created unhealthy forests. Large wildfires, such as the 2020 Wildfires in Monterey County, can cause housing inventories to become significantly limited thus increasing the demand on the housing market; additionally, many property owners have been unable to obtain or retain fire insurance at an affordable price or at all. Pre-existing water supply challenges in the County can lead to limited water available for fire suppression.
Cyber-Attack
Nearly every aspect of life in Monterey County is dependent on systems and resources connected and managed through computer systems. Cyber-attacks can have catastrophic impacts on the ability of government, public and private entities to access banking, electricity, water, telecommunications, transportation, and other information systems necessary for survival. Due to the tightly coupled nature of technological system and critical lifelines, any failure of service continuity could cost lives.
Utility Interruption/ PSPS
Heat-related equipment failures and electrical infrastructure igniting wildfires has resulted in unintentional and intentional rolling blackouts and power shutoffs throughout the County.
Public Safety/ Utility Initiated Power Shut Offs to prevent wildfire ignition can have notably significant impacts due to the length of disruption time, limited efficacy of the strategy, and the effect on first responder capabilities. Extreme and prolonged heatwaves across the state increase the demand for use of the aging electrical grid, significantly depleting electricity reserves resulting in blackouts. Heatwaves are expected to increase in intensity and magnitude due to climate change, which will likely exacerbate this problem. Traditional energy sources increase climate change risk and are failing more consistently, but energy alternative technology cannot meet current nighttime demand.
Additionally, Monterey County has limited microgrids and reliance on the macro-grid makes the County vulnerable to rolling and prolonged power outages. Over the last decade Monterey County residents have begun adjusting to the increasing unreliability of macro utilities. Loss of power for more than a few hours can result in large economic losses, specifically related to food and agriculture. More vulnerable populations in isolated areas or who rely on medical devices are at increased risk during prolonged power outages.
Localized Stormwater Flooding
Localized flooding has the potential to significantly impact people, property, and critical infrastructure in the County. Undersized and aging drainage infrastructure, deferred maintenance, increased run-off due to drought conditions, the built environment, and trends in precipitation and weather can all increase the risk of localized stormwater flooding. Climate change is likely to exacerbate the intensity and magnitude of precipitation events, increasing the risk associated with localized stormwater flooding causing drainage infrastructure to be undersized in increasingly more common events.
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Additionally, unhoused residents living in stormwater drainage areas can lead to increasing flood risk due to accumulated debris and trash, which can complicate both flood response and mitigation activities.
Severe Winter Storms
Severe winter storms have been increasing in intensity, magnitude, and severity in Monterey County and are associated with a variety of hazards in this Plan. Severe winter storms and heavy rain can have significant impacts including flash flooding, localized stormwater flooding, mudslides, and landslides. Secondary hazards can cause immobility and loss of utilities. Roads may become impassable due to flooding, downed trees, or landslides. Power lines may be downed due to high winds, and services such as water or telecommunications infrastructure may not be able to operate without power.
Stormwater runoff from heavy rains can also impair water quality by washing pollutants into water bodies. Severe winter storms can also cause large storm surge and wave action along the coastline, flooding low lying areas and causing dramatic erosion. Coastal bluff and cliff failure due to erosion can create hazardous conditions due to roadway collapse, undermined home foundations and damage to utilities. Additionally, future sea level rise scenarios are likely to exacerbate coastal and inland flood risks during winter storms.
Road Infrastructure
The occurrence of any hazard profiled in this Plan in combination with aging and limited road infrastructure can result in limited egress of evacuees and minimal ingress of first responders.
Roadways can be compromised in severe weather incidents, further limiting road capacity.
Road infrastructure is not developing at a rate commensurate with the rate that population and housing is expanding. Further, the topography of the County limits where new roads can be built.
MITIGATION ACTION PLAN
The Steering Committee and planning partners selected a range of appropriate mitigation actions to work towards achieving the goals set forth in this plan update, in addition to reducing risks identified in the problem statements. Mitigation actions presented in this update are activities designed to reduce or eliminate losses resulting from hazards. The update process resulted in the identification of mitigation actions for implementation by individual planning partners, as presented in Volume 2 of this plan.
The Steering Committee reviewed the catalogs of hazard mitigation alternatives and selected area-wide actions to be included in a hazard mitigation action plan. The selection of area-wide actions was based on the risk assessment of identified hazards of concern and the defined hazard mitigation goals and objectives. The countywide hazard mitigation action plan was designed to benefit the whole partnership. The countywide Hazard Mitigation Action Plan includes the following mitigation actions:
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Hazard Mitigation Action
Drought Provide public information on water conservation and assess the potential for community-wide water conservation programs.
Earthquake
Provide information on earthquake risk and preparedness to the public. Continue to adopt and implement current earthquake building standards and upgrade, remove, or replace unreinforced masonry buildings, as feasible.
Pandemic/ Epidemic
Provide unified information to the public regarding personal protective measures and mitigating strategies in accordance with CDC guidelines. Implement public health measures in government facilities.
Wildfire
Continue to collaborate across the operational area with all jurisdictions with fire protection and suppression responsibility on wildfire mitigation efforts.
Cyber-Attack
Seek to increase redundancy in IT infrastructure, implement protective cyber-security measures, and train staff on common cyber-attack methods.
Utility Interruption
Encourage the development of and use of microgrids and the hardening of utility of infrastructure, where possible. Provide backup generators for critical infrastructure and facilities.
Localized Stormwater
Flooding
Maintain good standing in the National Flood Insurance Program and encourage coordination on drainage system maintenance.
Severe Winter Storms
Maintain StormReady and TsunamiReady certification, as
applicable.
Climate Change Support, encourage, and implement, when feasible, countywide climate action, adaptation, and resiliency initiatives.
All Hazards
Incorporate and make consistent other planning documents with appropriate goals, policies, and objectives to address hazards identified within the Multi-Jurisdictional Hazard Mitigation Plan.
IMPLEMENTATION
The Steering Committee developed a plan implementation and maintenance strategy that includes annual progress reporting, a strategy for continued public involvement, a commitment to plan integration with other relevant plans and programs, and a commitment to actively maintain the plan over the performance period. Full implementation of the recommendations of this plan will require time and resources. The measure of the plan’s success will be its ability to adapt to changing conditions. The planning partners will assume responsibility for adopting the recommendations of this plan and committing resources toward implementation. The framework established by this plan commits all planning partners to pursue actions when the benefits of a project exceed its costs. The planning partnership developed this plan with extensive public input and support to help ensure the plan’s success.
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PART | A
A
PART A: PLANNING AND
COMMUNITY PROFILE
THIS PART PROVIDES AN OVERVIEW OF THE MULTI-JURISDICTIONAL HAZARD
MITIGATION PLAN, THE PLANNING PROCESS, AND COMMUNITY OF MONTEREY COUNTY. IT CONSISTS OF THE FOLLOWING SECTIONS:
1. INTRODUCTION
2. PLANNING PROFILE
3. COMMUNITY PROFILE
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COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 1-1 INTRODUCTION
1. INTRODUCTION
Disasters can cause loss of life, damage buildings and infrastructure, and have devastating consequences for a community’s economic, social, and environmental well-being. Nationwide, federal, state, and local governments spend billions of dollars annually to help communities, organizations, businesses, and individuals recover from disasters. This only partially reflects the true cost of disasters because additional expenses are incurred by insurance companies, nongovernmental organizations, non-profits, and individuals, which are not reimbursed by tax dollars. Many natural disasters are predictable, and much of the damage caused by these events can be reduced or even eliminated.
Hazard mitigation reduces disaster losses and damages. The term “hazard mitigation” is defined as sustained action or strategy taken to reduce or eliminate the long-term risk to human life and property from hazards. After disasters, repairs and reconstruction often are completed in such a way as to simply restore damaged property to pre-disaster conditions. These efforts may return property and infrastructure to “the norm,” but the replication of pre-disaster conditions may result in a repetitive cycle of damage and reconstruction. Hazard mitigation planning can break this repetitive cycle by reducing vulnerability to hazards through smart construction and proper planning of future development and critical infrastructure.
Mitigation activities can be developed, planned, and implemented before or after a disaster occurs. Hazard mitigation activities involve long- and short-term actions and include planning efforts, policy changes, programs, studies, improvement projects, and other steps to reduce the impacts of hazards. Implementing fuel reduction around buildings within high wildfire risk areas, outreach programs that increase risk awareness, projects to protect critical facilities, and
COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 1-2 INTRODUCTION
the removal of structures from flood hazard areas are all examples of mitigation actions. Local mitigation actions and concepts can also be incorporated into land use plans and building codes. Proactive mitigation policies and actions help reduce risk and create safer, more disaster resilient communities. Mitigation is an investment in the future safety and sustainability of Monterey County.
Monterey County and participating jurisdictions have prepared this update to the Monterey County Multi-Jurisdictional Hazard Mitigation Plan (MJHMP), which was originally approved by the California Governor’s Office of Emergency Services (Cal OES) and the Federal Emergency Management Agency (FEMA) in 2007 and updated in 2016. The plan in its current form reflects a comprehensive update in 2021. The purpose of this plan is to guide hazard mitigation planning in Monterey County in order to better protect the people and property from the effects of hazard events.
This plan demonstrates the commitment of each participating jurisdiction to reducing risks from hazards through mitigation and serves as a tool to direct resources to achieve optimum results with available administrative, technical, and financial resources. The plan will help guide and coordinate mitigation activities throughout Monterey County. This plan was also developed to ensure Monterey County and participating jurisdictions’ continued eligibility for certain federal disaster assistance, specifically the FEMA Hazard Mitigation Assistance (HMA) grants, including the Hazard Mitigation Grant Program (HMGP), Building Resilient Infrastructure and Communities (BRIC), and Flood Mitigation Assistance Program (FMA).
1.1 HAZARD MITIGATION PLANNING
Mitigation is most effective when it is based on a comprehensive, long-term plan that is developed before a disaster occurs. The purpose of mitigation planning is to identify policies and actions that can be implemented over the long term to reduce risk and future losses from hazards. The hazard mitigation plan provides an assessment of hazards, vulnerabilities, and risks prevalent in Monterey County and how those hazards may affect participating jurisdictions differently based upon proximities to hazards.
Mitigation actions are identified based on that risk assessment and the participation of a wide range of stakeholders and the public in the planning process. The mitigation strategy presented in this plan responds to the identified vulnerabilities within each community and provides actions to achieve the greatest risk reduction based upon available resources.
1.1.1 REGULATORY FRAMEWORK
For many years, federal disaster funding focused on relief and recovery after disasters occurred, with limited funding for hazard mitigation planning. The purpose of the Robert T. Stafford Disaster Relief and Emergency Assistance Act (Public Law 100-707), as amended by the Disaster COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 1-3 INTRODUCTION
Mitigation Act of 2000 (Public Law 106-390), is to reduce the loss of life and property, human suffering, economic disruption, and disaster assistance costs resulting from natural disasters.
The Disaster Mitigation Act (DMA 2000) shifted the federal emphasis toward planning for disasters before they occur and requires proactive pre-disaster planning as a condition of receiving certain federal financial assistance under the Stafford Act. Regulations developed to fulfill the Disaster Mitigation Act’s requirements are included in Title 44 of the Code of Federal Regulations (44 CFR). The Disaster Mitigation Act encourages state and local authorities to work together on pre-disaster planning and to assist local governments in accurately assessing mitigation needs, resulting in faster allocation of funding and more cost-effective risk reduction projects under FEMA’s Hazard Mitigation Assistance program.
The Disaster Mitigation Act requires the plan be updated every five years to remain in compliance with federal mitigation grant conditions. Grant compliance is contingent on meeting the plan update requirements that are contained in 44 CFR. Jurisdictions that allow a plan to expire are not able to pursue funding under the Stafford Act for which a current hazard mitigation plan is a prerequisite.
Federal regulations require a plan for monitoring, evaluating, and updating hazard mitigation plans. The plan update process provides an opportunity to reevaluate recommendations, monitor the impacts of actions that have been accomplished, and determine if there is a need to change the focus of mitigation strategies over time.
1.1.2 BENEFITS OF MITIGATION PLANNING
All citizens and businesses of Monterey County are the ultimate beneficiaries of hazard mitigation planning. This Plan seeks to reduce risk for those who live in, work in, and visit the County and provides a viable planning framework for all foreseeable hazards that may impact the County. Benefits of mitigation planning include:
• Identifying actions for risk reduction that are agreed upon by stakeholders and the public.
• Focusing resources on the greatest risks and vulnerabilities. • Building partnerships by involving citizens, organizations, and businesses. • Increasing education and awareness of threats and hazards, as well as their risks. • Communicating priorities to State and Federal officials. • Aligning risk reduction with other community objectives.
1.2 PURPOSE OF PLANNING AND THE PLAN UPDATE
The Monterey County Multi-Jurisdictional Hazard Mitigation Plan identifies resources, information, and strategies for reducing risk from hazards. Monterey County and the local jurisdictions that participated as planning partners initiated this planning effort for several key reasons. Monterey County has significant exposure to numerous hazards that have led to COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 1-4 INTRODUCTION
injuries and loss of life, in addition to millions of dollars in past damages. The planning partners want to be proactive in preparing for the probable impacts of hazards. Finally, limited local resources make it difficult to implement proactive risk-reduction measures. Federal and state financial assistance is paramount to successful hazard mitigation in the County. Elements and strategies in the MJHMP were selected because they best meet the needs of the planning partners and their citizens. The resources and background information in the plan are applicable countywide, and the Plan’s goals and recommendations can lay the groundwork for the development and implementation of local mitigation activities and partnerships.
As a DMA 2000 requirement, the plan must be updated every five years to remain in compliance with federal mitigation grant conditions. Monterey County first prepared a hazard mitigation plan in compliance with the Disaster Mitigation Act in 2007. The 2016 update to the Monterey County Multi-Jurisdictional Hazard Mitigation Plan was prepared by Monterey County Office of Emergency Services (OES) and AECOM. This plan is the update to the previous iterations of the plan and was updated with funding support from a FEMA Hazard Mitigation Grant Program Planning Grant (DR-4382-PL0025).
1.2.1 OBJECTIVES OF THE PLAN UPDATE
The 2021 update to the Monterey County Multi-Jurisdictional Hazard Mitigation Plan will help guide and coordinate mitigation activities and was developed to meet the following objectives:
• Meet or exceed the requirements of the Disaster Mitigation Act the and the 2015 California legislation requiring the incorporation of climate adaptation strategies into hazard mitigation planning (SB 379).
• Meet the needs of each planning partner as well as state and federal requirements. • Enable all planning partners to continue using federal grant funding to reduce risk through mitigation.
• Create a risk and vulnerability assessment that focuses on local hazards of concern. • Identify a comprehensive and integrated mitigation strategy for long term risk reduction. • Meet the planning requirements of FEMA’s Community Rating System (CRS) program, allowing planning partners that participate in the CRS program to maintain or enhance their classifications.
• Coordinate existing plans and programs so that high-priority projects to mitigate possible disaster impacts are funded and implemented.
• Create a single planning document that integrates all planning partners into a framework that supports partnerships within the County.
1.2.2 PARTICIPATING JURISDICTIONS
The County prepared this update in partnership with local municipalities and special districts.
One of the benefits multi-jurisdictional planning is the ability to pool resources and eliminate redundant activities within a planning area that has uniform risk exposure and vulnerabilities.
COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 1-5 INTRODUCTION
Any local government or non-profit agency with the ability to regulate building or infrastructure development or maintenance may participate in the planning process. However, to obtain FEMA approval, each of the local jurisdictions must meet all FEMA planning requirements outlined in 44 CFR Section 201.6.
The Monterey County Multi-Jurisdictional Hazard Mitigation Plan geographically covers the entire area of Monterey County and has multiple participating jurisdictions. A planning partnership was formed to develop and steer the content in this plan. This partnership consists of participating jurisdictions and Monterey County stakeholders. Partners worked together to create the goals, objectives, mitigation strategies, and implementation methods to reduce risk.
The following municipal jurisdictions have elected to become annexes of this plan update:
• Unincorporated Monterey County (and Monterey County Water Resources Agency) • City of Carmel-by-the-Sea
• City of Del Rey Oaks
• City of Gonzales
• City of Greenfield
• City of King
• City of Marina
• City of Monterey
• City of Pacific Grove
• City of Salinas
• City of Sand City
• City of Seaside
• City of Soledad
Additionally, the following special districts have elected to become annexes of this plan update:
• Monterey County Water Resources Agency (MCWRA) (in unincorporated annex) • Carmel Area Wastewater District (CAWD)
• Monterey Regional Waste Management District (MRWMD)
• Monterey One Water (M1W)
• Moss Landing Harbor District
All jurisdictions listed above participated in and were annexes to the 2016 Monterey County MJHMP, with the exception of the Monterey Regional Waste Management District (MRWMD) and the Moss Landing Harbor District, which are new to the 2022 Plan.
1.3 CONTENTS OF THE PLAN
This plan has been set up in two volumes so that elements that are jurisdiction-specific can easily be distinguished from those that apply to the whole County.
COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 1-6 INTRODUCTION
Volume 1: Countywide Hazard Mitigation Plan
Volume 1 includes the federally required elements of a hazard mitigation plan for all participating jurisdictions. This includes the description of the planning process, public involvement strategy, hazard risk assessments, countywide mitigation actions, and a plan maintenance strategy. Since this is a multi-jurisdictional plan, Volume 1 addresses the entirety of Monterey County, which includes all participating jurisdictions and the entire geographic boundary of the County. Volume 1 includes the following appendices:
• Appendix 1: Plan Adoption Resolutions from Planning Partners • Appendix 2: Plan Progress Report Template
Volume 2: Jurisdictional Annexes
Volume 2 contains the Jurisdictional Annexes, which detail the hazard mitigation planning elements specific to each participating jurisdiction in the Monterey County MJHMP Update and includes all federally required jurisdiction-specific elements for each participating jurisdiction.
Each annex is not intended to be a standalone document, but annexes to, supplements, and incorporates by reference the information contained in Volume 1 of the Plan. As such, all information in Volume 1, including the planning process and other procedural requirements and planning elements apply to and were met by each participating jurisdiction. The Annexes provide additional information specific to each participating jurisdiction, with a focus on providing additional details on the risk assessment and mitigation strategy. Jurisdictional Annexes in Volume 2 are organized in the following order:
A Unincorporated County of Monterey (and Monterey County Water Resources Agency) B City of Carmel-by-the-Sea
C City of Del Rey Oaks
D City of Gonzales
E City of Greenfield
F City of King
G City of Marina
H City of Monterey
I City of Pacific Grove
J City of Salinas
K City of Sand City
L City of Seaside
M City of Soledad
N Carmel Area Wastewater District
O Monterey One Water
P Monterey Regional Waste Management District
Q Moss Landing Harbor District
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All participating jurisdictions will adopt Volume 1 in its entirety and their own jurisdiction- specific annex in Volume 2. It should also be noted that the Monterey County Water Resources Agency as a dependent special district is covered under the Unincorporated Monterey County Annex. The Agency participated extensively in both the Steering Committee and the unincorporated County Hazard Mitigation Planning Team. The Plan will also be adopted by the Monterey County Water Resources Agency Board, in addition to its adoption by the Monterey County Board of Supervisors.
1.3.1 WHAT’S NEW?
In 2016, the County met all approval requirements from the DMA and officially adopted an update to the 2007 MJHMP. The 2016 Monterey County MJHMP contained descriptions of their planning processes, risk assessments of identified hazards, and mitigation strategies for reducing the risk and vulnerability from these hazards. Since the approval of the 2016 MJHMP by Cal OES and FEMA, progress has been made by the County and the participating jurisdictions on implementation of the mitigation strategies. As part of the update process, a thorough review and update of the 2016 MJHMP was conducted to ensure that this update reflects current community conditions and priorities in order to realign the updated mitigation strategy for the next five-year planning period.
Also, to be noted, Section 8, Plan Maintenance of the 2016 MJHMP and Section 22, Plan Implementation and Maintenance, of this MJHMP update identify key questions to be considered as criteria for assessing the effectiveness and appropriateness of the Plan during future plan updates. Questions include:
• Do the goals address current and expected conditions? • Has the nature or magnitude of risks changed?
• Are the current resources appropriate for implementing the Plan? • Are there implementation problems, such as technical, political, legal, or coordination issues with other agencies?
• Have the outcomes occurred as expected?
• Did the jurisdictions, agencies, and other partners participate in the plan implementation process as proposed?
Plan Reorganization
For this Plan update, a new plan organization was used. The hazard section was reorganized, combining Hazard Analysis and Vulnerability Analysis sections from the previous plan by hazard.
This allowed for a simpler document flow, which allows the reader to gain a full picture of the risk of any given hazard profiled in this plan in one individual section.
Changes in Development
Hazard mitigation plan updates must be revised to reflect changes in development within the planning area during the previous performance period (44 CFR Section 201.6(d)(3)). The plan must describe changes in development in hazard-prone areas that increased or decreased COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 1-8 INTRODUCTION
vulnerability for each jurisdiction since the last plan was approved. The intent of this requirement is to ensure that the mitigation strategy continues to address the risk and vulnerability of existing and potential development and takes into consideration possible future conditions that could impact vulnerability.
Monterey County experienced a 5.8% increase in population between 2010 and 2020.
Participating jurisdictions have adopted general plans that govern land use decisions and policymaking, as well as building codes and specialty ordinances based on state and federal mandates. This plan update assumes that some new development triggered by the increase in population occurred in hazard areas. Because all such new development would have been regulated pursuant to local programs and codes, it is assumed that vulnerability did not increase even if exposure did. Specific land use and development trends for each participating jurisdiction are included in their respective Annex in Volume 2. Risk assessments included update information on development in order to assess current exposure accurately.
New Hazards and Risk Assessment Methodology
The risk assessments for each identified hazard were updated. This included reworking the hazard profile, adding new hazard event occurrences, redoing the entire vulnerability analysis to add additional items, and updating the vulnerability assessment based on more recent hazard data as well as using the most current parcel and assessor data for the existing built environment to develop loss estimates.
The County strengthened this plan by using new research methods and information systems.
Geographic Information Systems (GIS) mapping and updated critical infrastructure inventories provided the County the tools to develop more comprehensive data sets than those in the 2016 MJHMP. The FEMA National Risk Index was also used to enhance the risk assessment. The National Risk Index incorporates physical and social vulnerability data to identify communities more at-risk to the adverse impacts of natural hazards. The National Risk Index is a high quality, comprehensive data set that identifies a community’s risk to natural hazards.
The 2016 MJHMP addressed the following hazards: agricultural emergencies coastal erosion, dam failure, earthquake, flood (including coastal storm), a hazardous materials event, landslide, tsunami, wildfire, and windstorm. As part of the plan update process new hazards of concern were identified and included in this update. Some hazards were reorganized or expanded to include additional sub-hazards. New hazards and changes include:
• Levee Failure added to Dam Failure
• Land Subsidence added to Earthquake Section
• Flooding was expanded to also include Localized Stormwater Flooding and Flash Floods • Landslide was renamed to Slope Failure to encompass a broader range of slope-based hazards
• Severe Weather added as a new section which included Windstorm in addition to Severe Winter Storms, Extreme Cold & Freeze, and Extreme Heat COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 1-9 INTRODUCTION
• Public Health Hazards added and includes Pandemic and Epidemic • Human Caused Hazards added and includes Cyber-Attack, Targeted Violence, Terrorism, and Mass Migration
• Utility Interruption added, including PSPS and Space Weather • The 2016 MJHMP described the anticipated effects of climate change on all hazards, as applicable, and for this update Climate Change risk analysis was expanded and combined into its own Section
• Sea Level Rise was moved under the new Climate Change Section Mitigation Actions
The 2016 mitigation actions were reviewed and have been changed, updated, and revised to reflect new priorities in this MJHMP. During this MJHMP update process, each of the 2016 mitigation actions were examined for relevancy and the potential for future implementation and then evaluated for potential follow-up. Some mitigation actions developed during the 2016 MJHMP effort are an inherent part of the MJHMP update process or were not detailed enough for implementation at a local jurisdiction level, and thus were not included in this update. The County has made significant changes to other 2016 Mitigation Actions because of the updated risk assessment and implementation strategy, to include more detail, or to update based on current mitigation practices.
During this MJHMP update process, the Steering Committee also decided to add countywide mitigation actions. These countywide actions were based on the highest rated hazards of concern the identified problem statements across the operational area. They were included in order to provide a high-level countywide mitigation strategy.
Mitigation Success Stories
The 2016 Monterey County MJHMP guiding principle, goals, objectives, and mitigation actions have been implemented through various ongoing projects, plans, and programs. The planning partners have made improvements toward reducing natural hazard risks to life and property, with significant risk reduction efforts for floodplain management, flood damage prevention, and fire hazard reduction. Throughout the hazard sections of the Plan, mitigation success stories were added in order to reflect on risk reduction successes that have occurred over the previous planning period. Mitigation success stories discussed in the Plan include:
• Section 5: Mitigating the Impact of the COVID-19 Pandemic to Farmworkers • Section 7: San Clemente Dam Removal
• Section 10: Severe Repetitive Loss Property Elevation • Section 10: Salinas River Stream Maintenance Program
• Section 14: City of Salinas Free Tree Program
• Section 15: Rain Rocks Shed/ Pitkin's Curve Bridge
• Section 18: Monterey Fire Defensible Space Inspection Program • Section 19: City of Gonzales Growing Green
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COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 2-1 PLANNING PROFILE
2. PLANNING PROFILE
This section describes each stage of the
planning process used to develop the
Monterey County Multi-Jurisdictional Hazard
Mitigation Plan. The planning process provides
a framework for document development and
follows the FEMA recommended steps as
enumerated in federal regulation and outlined
below.
FEMA recommends 4 major planning steps:
• Step 1: Organize Resources
• Step 2: Assess Risk
• Step 3: Develop a Mitigation Strategy
• Step 4: Adopt and Implement the Plan
This MJHMP is a community-driven, living
document. The planning process itself is as
important as the resulting plan because it
encourages communities to integrate
mitigation with day-to-day decision making.
This section describes each stage of the
planning process.
Organize
Resources
Assess Risk
Devleop a
Mitigation
Strategy
Adopt
and
Implement
the Plan
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Multi-Jurisdictional Planning Process
Multi-jurisdiction hazard mitigation planning offers many benefits, such as increased coordination and efficiency in planning and implementation efforts. At the same time, each jurisdiction has specific hazards and specific mitigation actions that must be addressed individually. The MJHMP balances the benefits of a comprehensive, coordinated approach to hazard mitigation with the specific realities of individual participating jurisdictions.
Volume 2 of this MJHMP documents each jurisdiction’s hazard mitigation planning process and resources. Each participating jurisdiction individually followed the same planning process as the countywide plan for their respective annex. Volume 2 provides each participating jurisdiction’s stand-alone annex.
2.1 PLANNING TIM ELINE
The planning process began in April of 2019. The original intention was to start public outreach and the content update in January of 2020. Milestones and tasks affiliated with the FEMA planning steps set the original anticipated closeout date for March 2022. Planning efforts were suspended for approximately 12 months due to several moderate to catastrophic disasters in Monterey County in 2020 and 2021. These large events included the COVID-19 Pandemic, the 2020 River Fire, the 2020 Carmel Fire, the 2020 Dolan Fire, subsequent recovery efforts, and the 2021 Atmospheric River/Post-Fire Flood Flows.
After being suspended, the planning and update process resumed in March 2021, with an anticipated closeout date of July 2023. Table 2-1 outlines the key milestones in the process.
Table 2-1: MJHMP Planning Timeline
Table 2-1
MJHMP Planning Timeline
Planning Stage Start Date End Date
Public Outreach May 2019 February 2021
Planning Process May 2019 March 2020
Planning and Update Process Suspended March 2020 March 2021 Planning Process (Continued) March 2021 January 2022
Update Process March 2021 January 2022
Plan Review February 2022 June 2022
Plan Adoption and Approval July 2022 July 2023
2.1.1 THE STEERING COMMITTEE
In line with the first step of the recommended planning process, organizing resources, a Steering Committee was developed. Monterey County OES opened this planning effort to all eligible local governments and special districts within the County. Each jurisdiction wishing to join the planning partnership was asked to provide a designated a point of contact for the jurisdiction who would serve as the jurisdiction’s Steering Committee representative, as well as confirm the jurisdiction’s commitment to the process and understanding of expectations.
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The Steering Committee was comprised of representatives from all participating jurisdictions who worked together to develop the MJHMP. Each jurisdiction’s Steering Committee representative was also the lead for their respective Jurisdictional Hazard Mitigation Plan Stakeholder Team.
The Steering Committee was at the core of the MJHMP planning process and was integral to ensuring its success, its implementation, and its future maintenance. Members of the Steering Committee, listed in Table 2-2, represented jurisdictional leads from each planning partner.
Table 2-2: 2022 MJHMP Steering Committee Members
Table 2-2
2022 MJHMP Steering Committee Members
Name Agency/Jurisdiction Title
Barbara Buikema Carmel Area Wastewater District General Manager Paul Tomasi City of Carmel-by-the-Sea Police Chief
Chris Bourquin City of Del Rey Oaks Police Commander
Jeff Hoyne City of Del Rey Oaks Police Chief
Jason Muscio City of Gonzales Fire Chief
Jim Langborg City of Greenfield Fire Chief
Doreen Liberto City of King Community Development Director Steve Adams City of King City Manager
Doug McCoun City of Marina Fire Chief
Gaudenz Panholzer City of Monterey Fire Chief
Alyson Hunter City of Pacific Grove Senior Planner
Skylar Thompson City of Salinas Fire Chief
Brian Ferrante City of Sand City Police Chief
Dave Nava City of Seaside Division Chief
Mary Gutierrez City of Seaside Fire Chief
George Nunez City of Soledad Fire Chief
John Dugan Monterey County Housing and
Community Development
Deputy Director of Land Use and
Community Development
Kelsey Scanlon Monterey County Office of
Emergency Services Emergency Services Planner
Jennifer Bodensteiner Monterey County Water
Resources Agency Associate Hydrologist
Sarah Stevens Monterey One Water Compliance Analyst
David Ramirez Monterey Regional Waste
Management District Senior Engineer
Tommy Razzeca Moss Landing Harbor District General Manager/ Harbormaster
The Steering Committee met throughout the development of the MJHMP update to discuss the MJHMP, its progress, and key planning elements. Table 2-3 provides an overview of those meetings, including dates and topics discussed.
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Agendas for all Steering Committee Meetings are included in Appendix 3.
Table 2-3: Steering Committee Meeting Schedule
Table 2-3
Steering Committee Meeting Schedule
Meeting Date Topics Discussed
Kick-Off Meeting May 22, 2019
• Overview of Hazard Mitigation
• Solicit Planning Partners
• Plan Expectations and Timeline
Planning Meeting #1 January 22, 2020
• Hazard Mitigation Overview
• Overview of Planning Process
• Roles, Responsibilities, and Tasks
• Public Outreach Strategy
• Information Requirements
Planning Meeting #2 February 19, 2020
• Planning Process Schedule
• Public Outreach Strategy
• Community Profile Review
• Information Requirements
Planning Meeting #3 March 2020 • Cancelled Due to COVID-19 Planning Meeting #4 April 2020 • Cancelled Due to COVID-19 Planning Meeting #5 May 2020 • Cancelled Due to COVID-19 Planning Meeting #6 July 15, 2020
• Progress Update
• COVID-19 Restrictions
• Timeline Changes
Planning Meeting #7 August 2021 • Cancelled Due to COVID-19 Planning Meeting #8 April 15, 2021
• Planning Process Timeline Update
• Plan Reorganization and Hazard List
• Upcoming Public Meetings and Survey
• Jurisdiction Information Requirements
Planning Meeting #9 May 21, 2021
• Jurisdiction-Specific Planning Meetings
• Information on Jurisdiction Annexes
• Threat Hazard Risk Assessment
Planning Meeting #10 September 21, 2021
• Countywide Mitigation Strategy
• Threat Hazard Risk Assessment Results
• Countywide Mitigation Actions
• Plan Maintenance Strategy
• Jurisdiction Annexes Overview
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Review and Incorporation of Existing Documents
The Steering Committee and the Monterey County OES Team reviewed and incorporated existing plans, studies, reports, and technical information in the formation of this MJHMP.
Those documents are referenced throughout the hazard sections and are examined more closely in Section 20, Capability Assessment.
2.1.2 STAKEHOLDER ENGAGEMENT
Per 44 CFR Section 201.6(b)(2), the planning process included an opportunity for neighboring communities, local and regional agencies involved in hazard mitigation activities, and agencies that have the authority to regulate development, as well as businesses, academia, and other private and non-profit interests to be involved.
In order to gather input from stakeholders on the risks and hazards facing Monterey County, the Threat Hazard Identification and Risk Assessment (THIRA) Survey, described in more detail in Section 4, Risk Assessment Methods, was sent out to neighboring communities, local and regional agencies, agencies that regulate development, businesses, academia, and other private and non-profit interests. Results from the survey were included with the rest of the Steering Committee and Jurisdiction results in the Countywide THIRA.
The agencies from whom stakeholders were invited to participate includes:
• American Red Cross
• American Water Works
• Association of Monterey Bay Area Governments (AMBAG)
• Big Sur Fire Brigade
• Cachagua Fire
• California American Water Company
• California Department of Fish and Wildlife
• California Department of Forestry and Fire Protection (CAL FIRE) • California Department of Transportation (Caltrans)
• California Governor's Office of Emergency Services (Cal OES) • California Highway Patrol (CHP)
• California State Parks
• California State University, Monterey Bay (CSUMB)
• Carmel Valley Recreation and Park District
• Castroville Community Services District
• Center for Ocean Solutions
• Central Coast Community Energy
• Central Coast Wetlands Group
• Community Emergency Response Volunteers (CERV) of the Monterey Peninsula • Cypress Fire Protection District
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• Elkhorn Slough National Reserve
• Gonzales Rural Fire Protection District
• Hartnell Community College
• Marina Coast Water District
• Mid Coast Fire Brigade
• Monterey Bay Aquarium Research Institute (MBARI)
• Monterey Bay Sanctuary Foundation
• Monterey County Office of Education
• Monterey County Regional Fire Protection District
• Monterey Peninsula Regional Park District (MPRPD)
• Monterey Peninsula Unified School District
• Monterey Regional Fire
• Monterey-Salinas Transit (MST)
• National Weather Service (NWS)
• Natural Resources Conservation Service (NRCS)
• Naval Postgraduate School
• North County Fire Protection District
• North County Recreation and Park District
• Pacific Gas & Electric (PG&E)
• Pajaro/Sunny Mesa Community Services District
• Pebble Beach Community Services District
• Resources Conservation District of Monterey County (RCDMC) • Salinas Valley State Prison.
• San Ardo California Water District
• San Benito County
• San Lucas County Water District
• San Luis Obispo County
• Santa Cruz Country
• Santa Lucia Community Services District
• Soledad-Mission Recreation District
• SPCA for Monterey County
• Spreckels Community Services District
• The Nature Conservancy
• United Way Monterey County
• US Army Garrison- Presidio of Monterey
• US Army Garrison-Fort Hunter Liggett
• US Environmental Protection Agency (EPA)
• US Forest Service - Los Padres National Forest
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2.1.3 JURISDICTION SPECIFIC PLANNING EFFORTS
Each jurisdiction conducted internal planning efforts with their individual jurisdiction planning teams to update their specific Annexes. These efforts were led by the Local Jurisdiction Lead who served as that jurisdiction’s Steering Committee representatives. Each Jurisdictions respective Steering Committee representative established their own Jurisdiction Hazard Mitigation Plan Stakeholder Team. Jurisdiction-specific Stakeholder Teams included, as applicable, those deemed relevant for local hazard mitigation and disaster risk reduction efforts and often included representatives from the following departments: City Management, Economic Development, Fire Department, Floodplain Administration, IT, Parks & Recreation, Community Development, Police Department, and Public Works. Details on the members of each Jurisdiction Hazard Mitigation Plan Stakeholder Team is included in Volume 2.
Each participating jurisdiction held at least one Jurisdiction Hazard Mitigation Planning Meeting.
At these meetings, the respective Hazard Mitigation Plan Stakeholder Team discussed hazard vulnerabilities, reviewed previous problem statements and mitigation strategies, and discussed their action plan. Each jurisdiction went through a risk ranking process using the Threat Hazard Risk Assessment (THIRA) Survey. This process is described in more detail in Section 4.4, Hazard Prioritization and Risk Ranking. Jurisdiction specific planning meetings are listed in Table 2-4.
Table 2-4: Jurisdiction-Specific Planning Meetings
Table 2-4
Jurisdiction-Specific Planning Meetings
Jurisdiction Meeting Date Location
City of Pacific Grove May 5, 2021 Virtual
City of Carmel-by-the-Sea June 15, 2021 Virtual
City of King June 22, 2021 Virtual
City of Seaside June 28, 2021 Virtual
City of Salinas July 13, 2021 City of Salinas City Hall City of Monterey July 19, 2021 Virtual
Monterey One Water (MW1) July 28, 2021 Regional Treatment Plant Carmel Area Wastewater District
(CAWD) August 2, 2021 CAWD Offices
City of Soledad August 18, 2021 City of Soledad City Hall City of Sand City August 24, 2021 City of Sand City City Hall Unincorporated Monterey County August 30, 2021 Virtual
City of Marina August 31, 2021 Virtual
City of Gonzales September 15, 2021 City of Gonzales Police Station City of Del Rey Oaks September 21, 2021 City of Del Rey Oaks City Hall City of Greenfield September 23, 2021 Virtual
Monterey Regional Waste
Management District (MRWMD) September 23, 2021 MRWMD Offices Moss Landing Harbor District September 27, 2021 Moss Landing Harbor City of Salinas October 5, 2021 City of Salinas City Hall COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 2-8 PLANNING PROFILE
2.2 PUBLIC ENGAGEMENT
Broad public participation in the planning process helps ensure that diverse points of view are considered and addressed. The public must have opportunities to comment on disaster mitigation plans during the drafting stages and prior to plan approval (44 CFR, Section 201.6(b)(1)). The public involvement strategy used for this plan update introduced the concept of mitigation to the public and provided the Steering Committee with feedback to use in developing the plan.
Public outreach was a critical element of the plan update process, as Monterey County includes a broad range of communities with diverse citizenry, concerns, and needs. A plan that reflects the community’s values and priorities is likely to have greater legitimacy and “buy-in” and greater success in implementing mitigation actions and projects to reduce risk. The public outreach strategy maximized involvement throughout the planning process.
Public stakeholders were given many opportunities to provide comment during all phases of the update process. The strategy for involving the public in this plan was a multi-pronged approach utilizing a dedicated website, a Community Survey, 7 Public Forums, and Public Presentations. Presentations were provided in Spanish upon request. The website and Survey were translated in Spanish to accommodate Spanish speaking community members.
2.2.1 WEBSITE
At the beginning of the plan development process, a website was created to keep the public posted on plan development milestones and to solicit relevant input. The site’s address was publicized at all public meetings. Each planning partner established a link to this site on its own agency website. Information on the plan development process, the Steering Committee, the Survey, and drafts of the plan was made available to the public on the site throughout the
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process. Monterey County OES intends to keep the website active after the plan’s completion to keep the public informed about successful mitigation projects and future plan updates.
2.2.2 SURVEY
A hazard mitigation survey was developed, in both English and Spanish, by the planning team with guidance from the Steering Committee. The survey provided an opportunity for residents to share opinions regarding hazard mitigation and participate in the plan update process. The survey consisted of 30 questions and was made available on the hazard mitigation plan website and advertised throughout the course of the planning process. The survey was used to:
• Gauge the public’s perception of risk and identify what citizens are concerned about. • Identify the best ways to communicate with the public. • Determine the level of public support for different mitigation strategies. • Understand the public’s willingness to invest in hazard mitigation.
The survey was open for public participation from July 22, 2019, to August 28, 2021, and 100 completed surveys were submitted.
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Data suggests a direct correlation between public outreach efforts and survey participation as seen in Figure 2-1.
Figure 2-1
Survey Responses to Date
Figure 2-1: Survey Responses to Date
Survey respondents represented a broad range of geographical areas. Table 2-5 summarizes the geographic diversity of respondents and Figure 2-2 shows a heat map of respondents.
Table 2-5: Public Survey Respondents by Location
Table 2-5
Public Survey Respondents by Location
Jurisdiction # of Respondents
City of Carmel by The Sea 1
City of Del Rey Oaks 2
City of Gonzales 0
City of Greenfield 0
City of King City 1
City of Marina 5
City of Monterey 27
City of Pacific Grove 5
City of Salinas 12
City of Sand City 0
City of Seaside 0
City of Soledad 1
Incorporated Jurisdiction Respondents Subtotal 54
Unincorporated Area- Big Sur 8
Unincorporated Area-Carmel 5
Unincorporated Area- Carmel Valley 9
Unincorporated Area - Salinas/River Rd 2
Unincorporated Area - North County 4
Unincorporated Area - Other 1
Unincorporated Area Respondents Subtotal 29
Other* 17
Total Respondents 100
*Respondents identified locations outside of County or did not identify their locations.
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Figure 2-2
Heat Map of Public Survey Respondents Locations
Figure 2-2: Heat Map of Public Survey Respondents
Results of the survey were used to support the creation of the Countywide Hazard Mitigation Problem Statements and the Countywide Hazard Mitigation Action Matrix.
Approximately 74% of survey participants indicated they had experienced or been impacted by a natural hazard or disaster. The most common hazards respondents had experienced or been impacted by were flooding (25 respondents), earthquakes (24 respondents), wildfires (23 respondents), and windstorms (19 respondents). Survey participants were most concerned about agricultural emergencies, earthquakes, and climate change.
Participants also ranked which community assets were most vulnerable to natural hazards.
Community assets were ranked by vulnerability in the following order:
1. Infrastructure: Damage or loss of roads, bridges, utilities, schools, etc.
2. People: Loss of life and/or injuries
3. Environmental: Damage, contamination or loss of forests, wetlands, waterways, etc.
4. Governmental: Ability to maintain order and continue providing public services, etc.
5. Economic: Business interruptions or closures, job losses, agricultural losses, etc.
6. Cultural/Historic: Damage or loss of libraries, museums, historic properties, etc.
In terms of mitigation activities, 81% of respondents felt natural systems protection was very important to pursue, 77% felt educations and awareness programs were very important to
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pursue, 73% felt local plans and regulations were very important to pursue, and 71% felt structure and infrastructure projects were very important to pursue.
The highest priority mitigation actions included: Strengthen infrastructure such as roads, bridges, water/wastewater and electric power supply facilities (83 respondents); Develop climate adaptation plans, policies or projects to minimize potential negative impacts from climate change (68 respondents); Enhance or restore the capacity of natural features (dunes, floodplains, wetlands) to absorb impacts of natural hazards (61 respondents); Strengthen critical public facilities such as police, fire, schools and hospitals (60 respondents); and Provide better public information about hazard risks and available mitigation measures (59 respondents).
The lowest priority mitigation actions included: Protect cultural and/or historic resources such as monuments, museums, historic landmarks, etc. (18 respondents); Assist vulnerable property owners with securing funding for mitigation projects (35 respondents); and acquire vulnerable properties from willing sellers, remove or relocate existing structures and maintain as open space (23 respondents).
Full survey results are available upon request.
2.2.3 COMMUNITY FORUMS
Monterey County OES held 7 Community Forums, geographically dispersed by Supervisorial District, in order to capture a wide range of community input on the update to the MJHMP.
Table 2-6 lists the community forums that occurred.
Table 2-6: Hazard Mitigation Community Forums on the 2022 MJHMP Table 2-6
Hazard Mitigation Community Forums on the 2022 MJHMP
District Date Location
District 1 January 8, 2020 Ag Commissioner’s Office
District 2 January 6, 2020 Castroville Library
District 3 January 15, 2020 San Antonio Valley Community Center District 3 January 17, 2020 Arroyo Seco Fire District Station #32 District 4 January 9, 2020 Marina Library
District 5 January 16, 2020 Big Sur Lodge Conference Room District 5 January 22, 2020 Discovery Center at Palo Corona Regional Park In order to assess the community’s perception of hazard risk, during the community forums, an interactive activity was conducted. The activity was offered in both English and Spanish.
Community members voted with stickers to answers questions on the importance of various community assets and their level of concern on different hazards. First, in order to understand the importance of various community assets, community forum participants indicated how COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 2-13 PLANNING PROFILE
important various community assets were to them. Community assets was defined as features, characteristics, or resources that either make a community unique or allow it to function.
Table 2-7 summarizes the results from all community forums on the answer to the question:
How important are each of the following community assets to you? The results indicate that over 90% of community members that responded considered Electric Power and Gas Facilities, Emergency Operations Centers, Hospital and Medical Facilities, Major Roads and Bridges, and Water and Wastewater Utilities to be very important.
Table 2-7: Community Forums Interactive Activity Results: Community Assets Table 2-7
Community Forums Interactive Activity Results: Community Assets Community Asset
Percent of Respondents
Very
Important
Somewhat
Important Neutral Not Very
Important
Not
Important
Airports 13.3% 66.7% 13.3% 0.0% 6.7%
Colleges/Universities 50.0% 28.6% 7.1% 14.3% 0.0%
Day Care Facilities 30.0% 40.0% 30.0% 0.0% 0.0%
Elder Care Facilities 64.3% 14.3% 21.4% 0.0% 0.0%
Electric Power and Gas Facilities 95.7% 0.0% 4.3% 0.0% 0.0% Emergency Operations Centers 93.3% 6.7% 0.0% 0.0% 0.0%
Emergency Shelters 87.5% 12.5% 0.0% 0.0% 0.0%
Farms and Agricultural Facilities 38.5% 46.2% 7.7% 7.7% 0.0% Fire Stations and EMS Facilities 80.0% 20.0% 0.0% 0.0% 0.0% Government Buildings 25.0% 37.5% 37.5% 0.0% 0.0%
Historic Buildings 41.7% 25.0% 25.0% 8.3% 0.0%
Hospital and Medical Facilities 92.3% 7.7% 0.0% 0.0% 0.0% Major Roads and Bridges 92.6% 7.4% 0.0% 0.0% 0.0%
Major Employers 28.6% 42.9% 28.6% 0.0% 0.0%
Military Facilities 14.3% 57.1% 14.3% 14.3% 0.0%
Natural Resources 85.7% 14.3% 0.0% 0.0% 0.0%
Parks and Recreational Areas 78.6% 21.4% 0.0% 0.0% 0.0% Police Stations 84.6% 15.4% 0.0% 0.0% 0.0%
Port and Marine Facilities 62.5% 25.0% 0.0% 12.5% 0.0%
Schools (K-12) 68.8% 25.0% 6.3% 0.0% 0.0%
Small Businesses 54.5% 45.5% 0.0% 0.0% 0.0%
Water and Wastewater Utilities 92.3% 7.7% 0.0% 0.0% 0.0% Next, in order to understand the community’s perception of hazard risk, community forum participants indicated how concerned they were about various hazards.
Table 2-8 summarizes the results from all community meetings on the answer to the question:
How concerned are you about the possibility of your community being impacted by each of these hazards?
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Table 2-8: Community Forums Interactive Activity Results: Hazard Concern Table 2-8
Community Forums Interactive Activity Results: Hazard Concern Hazard Percent of Respondents
Very Concerned Somewhat Concerned Not Concerned
Agricultural Emergency 73.9% 26.1% 0.0%
Coastal Erosion 70.0% 30.0% 0.0%
Dam Failure 55.6% 27.8% 16.7%
Earthquake 78.6% 21.4% 0.0%
Flood 80.0% 20.0% 0.0%
Hazardous Materials Incident 62.5% 25.0% 12.5%
Landslide / Debris Flow 69.4% 22.2% 8.3%
Sea Level Rise 64.7% 29.4% 5.9%
Tsunami 61.1% 22.2% 16.7%
Wildland Fire 73.1% 23.1% 3.8%
Windstorm 37.5% 58.3% 4.2%
2.2.4 PUBLIC PRESENTATIONS
In order to inform the public about the plan, public presentations were held. Presentations helped educate the public about existing hazards and mitigation strategies and allowed the public to provide feedback on the MJHMP. Public presentations are listed in Table 2-9.
Table 2-9: Public Presentations on the 2022 MJHMP Update Table 2-9
Public Presentations of the 2022 MJHMP Update
Public Presentation Date
Monterey County Board of Supervisors Tuesday, April 2, 2019 Monterey County Disaster Council Wednesday, April 24, 2019 Monterey County Disaster Council Meeting Wednesday, October 30, 2019 City of Gonzales City Council Meeting Presentation Monday, November 18, 2019 City of Pacific Grove City Council Meeting Presentation Wednesday, February 19, 2020 City of Sand City City Council Meeting Presentation Tuesday, March 3, 2020 City of King City Council Meeting Presentation Tuesday, August 25, 2020 City of Greenfield City Council Meeting Presentation Tuesday, September 22, 2020 City of Monterey City Council Meeting Presentation Tuesday, October 6, 2020 Monterey County Disaster Council Meeting Wednesday, October 28, 2020 Carmel-by-the-Sea Climate Change Committee Meeting Thursday, November 19, 2020 City of Marina City Council Meeting Presentation Tuesday, May 18 2021 City of Carmel-by-the-Sea City Council Presentation Tuesday, June 1, 2021 City of Seaside City Council Meeting Presentation Thursday, June 3, 2021 Monterey Regional Waste Management District Board Friday, June 18, 2021 City of Soledad City Council Meeting Presentation Wednesday, July 21, 2021 City of Salinas City Council Meeting Presentation Tuesday, August 10, 2021 City of Del Rey Oaks City Council Meeting Presentation Tuesday, September 28, 2021 Moss Landing Harbor District Board Presentation Wednesday, September 29, 2021 COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 2-15 PLANNING PROFILE
2.3 ASSESS THE RISK
In accordance with FEMA requirements, the Steering Committee identified and prioritized the hazards affecting both the County as a whole and each participating jurisdiction individually. It also assessed the vulnerability to those hazards. Results from this risk assessment aided in the subsequent identification of appropriate mitigation actions. While the process is described below, the substance of this risk assessment is detailed in Section 4, Risk Assessment Methods.
Identify and Profile Hazards
Based on a review of past hazard events, existing plans, reports, and other technical studies, data, and information, the Steering Committee determined what regional hazards could affect the County. The Steering Committee completed a screening and prioritization processes to determine priority hazards to be assessed. A risk assessment finalized the prioritization process by ranking hazards according to the impact and threat to the whole County in Volume 1 and each participating jurisdiction in Volume 2.
Assess Vulnerabilities
Assessing vulnerabilities exposes the unique characteristics of individual hazards and begins the process of narrowing down which areas within the County are vulnerable to specific hazard events. The vulnerability assessment involved a subjective assessment, in addition to a GIS overlaying method for examining vulnerabilities in-depth. The identified hazards varied depending on the geographic make-up of, priorities of, and services provided by the participating jurisdictions. Using these methods, planning partners estimated vulnerable populations, infrastructure, and potential losses from hazards.
2.4 DEVELOP A MITIGATION STRATEGY
This plan provides an explicit strategy and blueprint for reducing potential losses identified in the risk assessment based on existing authorities, policies, programs and resources, and participating jurisdictions’ abilities to expand on and improve these existing tools. MJHMP development included identifying goals, assessing existing capabilities, reviewing the 2016 MJHMP goals, and identifying new mitigation actions. The MJHMP was prepared in accordance with requirements from DMA 2000 and the California Governor’s Office of Planning and Research (OPR) and FEMA’s HMP guidance. The process is described below; the substance of the mitigation strategy is detailed in Section 21, Mitigation Strategy, for the whole County and within Volume 2 for each participating jurisdiction.
Identify Goals
The Steering Committee reviewed the 2016 MJHMP goals and determined their current validity, consistent with FEMA requirements. The goals were updated to meet the current hazard environments and to be consistent with the changing policies and goals of participating jurisdictions. The goals are presented in Section 21, Mitigation Strategy.
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Develop Capabilities Assessment
A capabilities assessment is a comprehensive review of participating jurisdictions’ capabilities and tools to implement the mitigation actions in the MJHMP. The Steering Committee and individual jurisdiction Planning Teams identified technical, financial, and administrative capabilities to implement mitigation actions, as detailed in Section 20, Capability Assessment, and in Volume 2 for each participating jurisdiction.
Identify Hazard Problem Statements
The Steering Committee and individual jurisdiction Planning Teams developed mitigation actions, as both planning activities and projects, to address problems that could originate from hazards identified in the risk assessment, in line with identified capability of each jurisdiction.
Mitigation actions were created first by developing problem statements for prioritized hazards.
Hazard Problem Statements are located at the conclusion of each hazard section, in Section 21, Mitigation Strategy, and in Volume 2 for each individual jurisdiction.
Identify Mitigation Actions
As part of the MJHMP planning process, the Steering Committee and individual jurisdiction Planning Teams reviewed and analyzed the status of the mitigation actions identified in the 2016 MJHMP. The status of mitigation actions included in the 2016 MJHMP that were either completed or deleted during the plan update process is included in Volume 2 in the respective annexes of each jurisdiction who were included in the prior plan. Once the 2016 actions were reviewed, the Steering Committee and individual jurisdiction Planning Teams then worked to identify and develop new mitigation actions with implementation elements. Additional detail on these mitigation actions is provided in Section 21, Mitigation Strategy, and in Volume 2 for each individual jurisdiction.
2.5 ADOPT AND IMPLEMENT THE PLAN
Once the risk assessment and mitigation strategy were completed, information, data, and associated narratives were compiled into the MJHMP. Section 1.3.1, What’s New?, provides detailed information on new and updated elements of the MJHMP.
Plan Review and Revision
Once the Draft MJHMP Update was completed, a public and government review period was established for official review and revision. Public comments were accepted, reviewed, and incorporated into this update. Applicable comments from the public have been received and addressed prior to submitting to FEMA and Cal OES. Steering Committee Members, Operational Area stakeholders, and partners were provided a 60-day review period prior to the public review and comment period. This was announced at the Monterey County Operational Area Disaster Council meeting on October 27, 2021.
A 30-day public comment period, from February 10 to March 10, 2022, gave the public an opportunity to comment on the draft plan update prior to its submittal to Cal OES. The principal COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 2-17 PLANNING PROFILE
avenue for public comment on the draft plan was the website established for this plan update.
C
omments received on the draft plan are available upon request. All comments were reviewed b
y the Steering Committee and incorporated into the draft plan as appropriate.
P
lan Approval and Submittal
On behalf of all participating jurisdictions, Mont erey C ounty Office of Emergency Services submitted the Plan for Cal OES and FEMA Review on March 11, 2022. The 2022 Monterey County MJHMP received Approval Pending Adoption from FEMA on June 14, 2022.
Plan Adoption
Upon receiving the notice of Approval Pending Adoption, all participating jurisdictions seeking plan approval are required to adopt the plan. The plan approval date re mains t he same regardless of the independent participating jurisdictions adoption dates.
Table 2-10: Jurisdiction Plan Adoption Dates
Table 2-10
Jurisdiction Plan Adoption Dates
Annex Letter Agency/Jurisdiction Adoption Date
A Unincorporated County of Monterey
A Monterey County Water Resources Agency
B City of Carmel-by-the-Sea
C City of Del Rey Oaks
D City of Gonzales
E City of Greenfield
F City of King
G City of Marina
H City of Monterey
I City of Pacific Grove
J City of Salinas
K City of Sand City
L City of Seaside
M City of Soledad
N Carmel Area Wastewater District
O Monterey One Water
P Monterey Regional Waste Management District
Q Moss Landing Harbor District
Upon receiving the record of adoption from the State, FEMA will issue an official approval letter stating which jurisdictions have adopted and are approved and eligible for FEMA Hazard Mitigation Assistance programs. The approval letter and date are generated with the first jurisdiction adopting the plan. The Monterey County MJHMP was approved on DATE and expires on DATE.
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Implement, Evaluate, and Revise the Plan
The true worth of any mitigation plan is its implementation and success under FEMA’s grant programs. This MJHMP has been assembled to reduce the risk of natural hazards, and also to meet the requirements of the DMA 2000 and maintain eligibility under FEMA’s Hazard Mitigation Assistance (HMA) grant programs. FEMA administers three programs that provide funding for local agencies with approved mitigation plans:
• Hazard Mitigation Grant Program (HMGP), which assists in implementing long-term hazard mitigation planning and projects following a Presidential major disaster declaration. • Building Resilient Infrastructure and Communities (BRIC), which provides funds for hazard mitigation planning and projects on an annual basis.
• Flood Mitigation Assistance (FMA), which provides funds for planning and projects to reduce or eliminate risk of flood damage to buildings that are insured under the National Flood Insurance Program (NFIP) on an annual basis.
Plan Maintenance
The County will update and monitor this plan in accordance with all FEMA requirements in order maintain eligibility for FEMA HMA. Evaluation and revision procedures for this plan are detailed in Section 22, Plan Implementation and Maintenance . S
ection 22 includes the
measures Monterey County and planning partners will take to ensure the MJHMP’s continuous long
-te
rm implementation, including MJHMP monitoring, reporting, evaluation, maintenance, and updating.
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3. COMMUNITY PROFILE
Monterey County is situated on California's central coast, south of San Francisco and north of Los Angeles. Monterey County is known to the world for its majestic coastlines including Big Sur, the Monterey Peninsula, and the Monterey Bay, as well as the agriculturally rich Salinas Valley, known as the “Salad Bowl of the World.” It is also home to Pinnacles National Park near the City of Soledad, the Monterey Bay Aquarium, and the site of a Monarch butterfly preserve in the City of Pacific Grove.
3.1 LOCATION, GEOGRAPHY, AND CLIMATE
Monterey County is located on the Pacific Ocean on the north-central coast of California. The County is bordered by Santa Cruz County to the North, San Benito, Fresno, and King Counties to the East, San Luis Obispo County to the South, and the Pacific Ocean to the West. The County is 110 miles south of San Francisco and 320 miles north of Los Angeles.
Monterey County, one of the largest in California, covers 3,771 square miles, of which 13% is water, and contains nearly 100 miles of coastline. Elevation within the County ranges from sea level to 5,862 feet at Junipero Serra Peak, which is located 12 miles inland in the Santa Lucia Range. Prominent land features in the County include two major northwest-southeast trending mountain ranges—the Santa Lucia Range along the coast, and the Gabilan Range along the eastern border of the County, both of which are part of the Pacific Coast Range. Between the Santa Lucia and Gabilan mountain ranges lies the Salinas Valley; and at the center of the Valley flows the Salinas River, the largest river on California’s Central Coast.
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Figure 3-1
Map of Monterey County
Figure 3-1: Map of Monterey County
The Santa Lucia Range stretches approximately 100 miles from just south of Carmel to a point north of the San Luis Obispo County line. The steepest slope in the contiguous United States occurs within the Coast Range at Cone Peak, ranging from sea level to 5,155 feet in a distance of just three miles. The Big Sur coastline is known for its steep slopes, jagged peaks, and narrow coastal canyons. Offshore the steep ridges of the Santa Lucia Mountains fall sharply beneath the Pacific Ocean. 50 miles offshore, the Pacific Ocean reaches a depth of 12,000 feet. Two deep submarine canyons, the Sur Submarine Canyon, and the Partington Submarine Canyon, cut into the continental shelf near the Big Sur coast, and eventually merge to become one of the deepest submarine canyons on earth.
On the eastern side of the Santa Lucia Range, the mountain slopes descend abruptly down to the Salinas Valley, which rises in altitude from sea level at the Monterey Bay to approximately 400 feet near Bradley. The Valley is 130 miles long and is famous for its productive soils.
The Gabilan Mountains, like the Santa Lucia Mountains, are composed of granite and metamorphic rocks and are similarly characterized by steep slopes and complex drainage patterns. The Gabilan Mountains, located further inland however, are drier than the Santa Lucia
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Mountains. At the northern end of the Monterey County lies the Pajaro River. Much of north County land is cultivated with agricultural crops. The coastal area of North County contains wide sandy beaches and the primary commercial fishing harbor for the entire County.
Monterey County includes 12 incorporated cities and 16 unincorporated areas; of which Salinas, the County seat, is the largest municipality. The cities can be generally grouped into two classifications (valley and coastal):
Valley Cities: Gonzales, Greenfield, King City, Salinas (Monterey County seat), and Soledad.
Coastal Cities: Carmel, Del Rey Oaks, Marina, Monterey, Pacific Grove, Sand City, and Seaside.
California Highway 101 bisects the County providing easy access to all Salinas Valley cities and the Monterey Peninsula, while Highway 1 offers scenic views of the California coast.
The climate in Monterey County is considered Mediterranean, with dry summers, rainy winters, and moderate temperatures year-round, with an average rainfall of about 19 inches per year.
Precipitation in the region falls mainly between November and April. Large variations exist in rainfall amounts between coastal and inland areas, as well as from year to year and from sea level to altitude along the coast.
3.2 HISTORY
Before the European colonization, the Monterey area had been inhabited for over 8,000 years.
Indigenous peoples lived in the valleys and near the seaside and the area was inhabited by three major native groups: the Costanoan (Ohlone), Esselen, and Salinan groups. The Salinan Indigenous Americans lived in southern region of the County and had about 3,500-4,000 members. The Esselen Indigenous Americans had several hundred members and resided on the northwest coast of the County. The Costanoan (Ohlone) group was the largest in the area with around 7,000 people, occupying Monterey Peninsula and northern region of the County.
Spanish explorers first sailed past the Monterey coast in the mid-1500s but did not land in the Monterey Bay until the early 1600s. In 1542, Juan Rodriguez Cabrillo discovered the bay he named “la Bahia de los Pinos,” the Bay of Pines, but not venture ashore. By the late 1500s, New Spain's concerns were focused on the Pacific, in particular, the threat of English piracy against Spain's Manila galleons. With a view toward finding a port to protect and supply the galleons, Sebastian Vizcaino laid claim to the bay in 1602, when he named it, the Bahia de Monte Rey, or Monterey Bay, in honor of Gaspar de Zuniga y Acevedo, Conde de Monterrey, the Viceroy of New Spain. The word itself is composed of the “monte” and “rey,” which literally means “king of the mountain” in Spanish. Spanish settlement in the region though did not occur for another 167 years. It would not be until 1769, when New Spain, fearing the advancement of the Russians, planned an expedition into California to establish a military foothold and a mission.
On June 3, 1770, Captain Gaspar de Portola, and Franciscan Father Junipero Serra founded the Presidio of Monterey and the Mission de San Carolos Borromeo de Monterey at Monterey Bay.
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In 1774, the small, rudimentary presidio was named the capital of the Californias, both Alta and Baja, upper and lower. And, in 1778 it was named the capital of Spanish Alta California.
Spanish settlers began developing catholic missions, or religious outposts, within the County and used the Salinas Valley for range lands. Franciscan missionaries also began constructing missions in the late 1700s, establishing missions in Monterey (1770, then moved to Carmel in 1771), in the San Antonio River Valley (1771) along the eastern side of the Santa Lucia Mountains, and in Soledad (1791). This began a period of forced conversions of Indigenous Americans to Catholicism and the disintegration of traditional Indigenous life. Natives were decimated by introduced European diseases, particularly whooping cough, and measles, and by violence in the missions and declining birth rates. In 1826, after Mexico’s secession from Spain, the governor of Alta California emancipated the remaining natives from the missions. A small number of their descendants still live in the region.
Monterey was an important port and military position, for Spain, becoming the political and cultural Capital of Alta California in 1775. Spain established a formal pueblo government in the region that went into effect in 1794. By 1800, most settlers in the area lived in the Presidio or at the mission in Carmel, while a few had moved out to ranches south of Salinas. Slowly, settlers began moving into the Salinas Valley and developing ranches centered around cattle. The region remained a military outpost for most of Spanish rule. Spanish occupation of the Monterey County region significantly expanded grasslands, especially in the Salinas Valley, to support an economy based primarily on cattle grazing. The Spanish also introduced a number of important crops to the region, including wine grapes, olives, apples, and pear trees.
In 1822, following the Mexican War of Independence, California became a province of Mexico.
Monterey remained the capital of Alta California during the 20-year period of Mexican rule.
Under Mexican rule, with the secularization of the missions, the Californios, the descendants of the original Spanish colonists, secured vast land grants and expanded the cattle and hide trade.
The boundaries of the original ranchos serve to a large extent as today’s property boundaries within the region, particularly on larger tracts of agricultural and ranching lands. Mexico lifted the strict trading regulations the Spanish had enforced, and Monterey became California’s main port of entry. British, American, and South American trading vessels flocked to the coastal port.
The official Custom House at Monterey opened to foreign ships, transforming the old Spanish provincial capital into an international port.
Tensions between the US and Mexico rapidly deteriorated in the 1840s as American expansionists eagerly eyed land to the west, including the lush northern Mexican province of California. Indeed, in 1842, a US naval fleet, incorrectly believing war had broken out, seized Monterey. Monterey was returned the next day, but the episode only added to the uneasiness between Mexico and the US. In the mid-1800s, during the Mexican American war, the Presidio of Monterey was taken over by the US military. In July 1846, Commodore John Drake Sloat’s troops officially raised the American flag over the Custom House, setting the stage for California to become part of the US. Sloat established the first American fort in California to protect the COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 3-5 COMMUNITY PROFILE
harbor. Following the Mexican American War, the Treaty of Guadalupe Hidalgo, signed in February 1848, formally ceded Alta California, which included Monterey County, to the United States. US Navy Captain Walter Colton was appointed Monterey’s first American Alcalde or Chief Magistrate of the Monterey district in 1846. He impaneled the first jury in California, co- founded the first newspaper in California, was one of the founders of the first public library in California, and raised funds to build Colton Hall, the first and largest public building in California, as a town hall and school. In 1849, the new building became the site of the convention to establish a constitution for American California.
Settlement of Monterey County following its entry into the US, was at first concentrated around the establishments of earlier settlers. As ranchos were subdivided and settlers applied for preemption to public lands, clustered farms appeared in the canyon mouths that opened on to the Salinas Valley. The discovery of gold in the Sierra Nevada foothills in 1849 brought droves of homesteaders to the County, and as the best parcels in Monterey and the Salinas Valley became occupied, homesteading spread to the rugged Big Sur coast. Many of the first American settlers were cattlemen like the Spanish before them, and sheep were raised in large numbers, both in the Salinas Valley and in the hills of the Big Sur coast. Grazing eventually gave way to irrigated agriculture. The gold rush sparked the development of the Southern Pacific railroad and, as the railroad system grew in late 1800s, so did the Salinas Valley population.
David Jacks, a controversial figure in Monterey history, involved himself in the settlement of Mexican land claims in Monterey. In 1853 the Pueblo of Monterey contracted Delos Ashley to help legalize its title to some 30,000 acres of land. Ashley billed the city $1,000 for his services and when they could not pay, he suggested the city auction some of its land. Ashley and Jacks were the only two bidders and purchased the entire tract for $1002.50, which included what is now the cities of Monterey, Pacific Grove, Seaside, and Del Rey Oaks along with the Del Monte Forest, and Fort Ord. The sale was controversial, and the city filed suit against Jack claiming the sale was illegitimate. The case eventually reached the US Supreme Court in 1903, which ruled in favor of Jack. Jack embarked on what appears to have been an almost obsessive taste for land acquisition. Piece by piece he added to his holdings through mortgage and tax sales and other shrewd practices. As a result, of Jack’s shrewd business practices, animosity toward him ran high. At his height Jack was said to own around 100,000 acres of Monterey County land.
The gold rush created a cattle boom, which ended with major flooding in 1862, shifting the use of land from ranching to dry farming of grains. By 1870, commercial agriculture was well underway in the Salinas Valley. A major drought in 1863 and 1864 essentially wiped out the cattle industry, and grain production became the County’s principal agricultural activity. Sugar beet cultivation and dairying began to replace grain farming by 1897. In 1874, the first railroad was established, the Monterey and Salinas Valley Railroad, shipping grain, fish, and other goods. Soon, the narrow gauge was overtaken by the Southern Pacific Railroad. The extension of the Southern Pacific Railroad from Pajaro to Salinas, along with improved irrigation systems, refrigerated freight cars, and other innovations in technology, encouraged increasingly COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 3-6 COMMUNITY PROFILE
intensive row crop cultivation and set the stage for the Salinas Valley to become one of the most productive agricultural regions in the world.
The wealth of sea life around the Monterey Peninsula, from migrating whales to abalone and squid, also attracted settlers to the region. By 1853, Chinese settlers had established a vibrant fishing village, making the Monterey villages unique in early Chinese immigration to California.
The Chinese would continue their livelihood, despite fire and hardships. They were joined on the Bay by Portuguese whalers from the Azores who found a lucrative and dangerous livelihood in shore whaling.
The sugar beet industry in Monterey County was the first type of intensive farming to bring changes that would profoundly affect land use, labor, and settlement. In 1897, Claus Spreckels began a sugar beet industry in Monterey County. The success of the industry was dependent on contracted growers and a large body of low-wage laborers. These needs had a tremendous effect on tenancy and colonization of agricultural lands in the County, and greatly influenced the ethnic makeup of the Salinas Valley. The operations in Monterey County did not experience gradual growth but were put in place in the form of a fully planned town and plant, with company owned farms scattered from Salinas to King City. Spreckels did most of the pioneer work in irrigation technology in the County, paving the way for more efficient use of the seasonally scarce water supply that had hindered intensive farming efforts up to this time.
Beets, however, were eventually replaced by row crops which had a higher value per acre.
David Jacks sold a large tract of land between Carmel and Pacific Grove to the Pacific Improvement Company, a company controlled by the so-called "Big Four" California railroad barons. Railroad pioneer Charles Crocker sought to create a destination for the railroad, the Hotel Del Monte with gardens, polo fields, a racetrack, and a seventeen-mile leisure road to the Del Monte’s Pebble Beach. The hotel opened in 1880 and was immediately dubbed the “The World's Most Elegant Seaside Resort.” Hotel Del Monte was the catalyst for Monterey's modern-day tourism industry and at its peak encompassed 20,000-acres spread across the Monterey Peninsula. The Hotel Del Monte was requisitioned by the Navy at the beginning of World War II and in 1947, the resort was sold to the federal government.
Following the Spanish-American War, the need for more bases on the West Coast prompted the Army to establish the Monterey Military Reservation on the same site as the, the old fort on Presidio Hill (the American Presidio in contrast to the Royal Presidio located east of Old Town).
In 1904, it was renamed the Presidio of Monterey in honor of the original Spanish and Mexican presidio. From 1902 onward the mission of the Presidio changed from 19th century coastal defense to instruction and training, which it continues today as the home of the Defense Language Institute. The 1900s were a time of military growth for Monterey County with Fort Ord’s creation in Seaside during World War I and Camp Roberts development in South County during World War II. However, in recent history, base closures have resulted in reductions of military presence in the County, and the reuse of major portions of the former Fort Ord.
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A phenomenal expansion in lettuce production took place starting in 1920, and by 1930 lettuce accounted for almost half the gross returns to the County from farm products. The resulting increase in total farm income was reflected in a substantial growth in population. The need for seasonal field labor was firmly established with the shift to intensive single crop production. By 1930, a permanent shift in agricultural production to corporate owners and large operators who packed and shipped as well as grew the crop had taken place in the County. During the late 1930s and 40s the Salinas Valley witnessed a significant boom in agricultural production due to the development of farming infrastructure in the region. This led to a higher demand for labor that was satisfied due to the influx of farmworkers from Mexico during World War II, through the “Bracero” program. During and after the Dust Bowl, the Salinas Valley received thousands of displaced workers from the South and Midwest. Displaced workers led to a vast increase in agricultural productivity. The commercial farming sector of the Dust Bowl era forms the backdrop for several John Steinbeck novels.
In the early 1900s, the Monterey Bay began to attract the interest of commercial fish processors. In 1900, the first sardine cannery opened, adjacent to the Monterey Wharf and in 1902, the first fish packing and canning operation on Cannery Row. In 1903, Frank Booth took over the sardine cannery and would hire a Norwegian fisheries expert, Knut Hovden, to mechanize the canning process. Hovden would go on to revolutionize the canning industry and successfully operated the largest and longest operating cannery. By the 1940s, nineteen fully operating canneries harvested over 250,000 tons per season on "Cannery Row,” making Monterey the “Sardine Capital of the World.” In the late 1940s the sardine harvests diminished year by year signaling the end of the industry. The Monterey Bay Aquarium opened in 1984 at the old Hovden cannery site. Designated in 1992 as the Monterey Bay National Marine Sanctuary, an enormous federally protected marine area of California's central coast was created, centered on Monterey Bay.
3.3 POPULATION AND DEMOGRAPHICS
According to the 2020 Census, Monterey County has a population of 439,035 people. About 80% of the countywide population resides in the 12 incorporated municipalities, which consist of only 2% of the County’s total land area.
Salinas represents the largest city in Monterey County with over 163,542 residents. The cities of Marina, Soledad, Monterey, and Seaside form the second largest group in population ranging from 22,359 to 33,366 residents each. The smallest cities include Sand City, Del Rey Oaks Carmel-by-the-Sea and Gonzales with populations ranging from 325 to 8,647. The population for the unincorporated areas of the County is 104,482. The largest communities in the unincorporated County are Prunedale (18,885 residents), Castroville (7,515 residents), Carmel Valley Village (4,524 residents), and the Del Monte Forest (4204 residents). Since the 2010 Census the population of Monterey County has increased 6%. The largest population growth occurred in Greenfield (16%), Marina (13%), Salinas (9%), and Monterey (9%).
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Table 3-1 lists the total land area, population, percentage change in population since 2010, and population density (in persons/per square mile) for each jurisdiction.
Table 3-1: Total Land Area and Population in Monterey County Table 3-1
Total Land Area and Population in Monterey County
Jurisdiction Land Area
(Square Miles)
Population
(2020)
Population
Density
Population
(2010)
Percent
Change
Incorporated Cities 67.06 334,553 4,988.9 314,844 6%
Carmel-by-the-Sea 1.08 3,220 2,981.5 3,722 -13%
Del Rey Oaks 0.48 1,592 3,316.7 1,624 -2%
Gonzales 1.92 8,647 4,503.6 8,187 6%
Greenfield 2.14 18,937 8,849.1 16,330 16%
King City 3.84 13,332 3,471.9 12,874 4%
Marina 8.88 22,359 2,517.9 19,718 13%
Monterey 8.47 30,218 3,567.7 27,810 9%
Pacific Grove 2.86 15,090 5,276.2 15,041 0%
Salinas 23.18 163,542 7,055.3 150,441 9%
Sand City 0.56 325 580.4 334 -3%
Seaside 9.24 32,366 3,502.8 33,025 -2%
Soledad 4.41 24,925 5,651.9 25,738 -3%
Unincorporated Areas 3,213 104,482 32.5 100,213 4%
Aromas 4.75 2,708 570.1 1,358 99%
Boronda 0.55 1,760 3,200 1,710 3%
Bradley 0.09 69 766.7 93 -26%
Carmel Valley Village 19.20 4,524 235.6 4,407 3%
Castroville 1.06 7,515 7,089.6 6,481 16%
Chualar 0.63 1,185 1,881.0 1,190 0%
Del Monte Forest 10.65 4,204 394.7 4,514 -7%
Elkhorn 4.83 1,588 328.8 1,565 1%
Las Lomas 1.04 3,046 2,928.8 3,024 1%
Lockwood 10.91 368 33.7 379 -3%
Moss Landing 0.60 237 395.0 204 16%
Pajaro 0.93 2,882 3,098.9 3,070 -6%
Pine Canyon 3.34 1,871 560.2 1,822 3%
Prunedale 46.20 18,885 408.8 17,560 8%
San Ardo 0.45 392 871.1 517 -24%
San Lucas 0.39 324 830.8 269 20%
Spreckels 0.12 692 5,766.7 673 3%
Other Unincorporated 3,107 52,232 16.8 51,377 2%
Total 3,280 439,035 133.9 415,057 6%
Source: US Census Bureau, 2020 Census & 2010 Census
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Monterey County’s population growth has been fairly constant for the past 30 years, increasing steadily since the 1980s. Population projections for Monterey County ranging from 2030 to 2060, according to the California Department of Finance, are: 464,124 (2030); 477,265 (2040); 481,305 (2050); and 476,734 (2060). 1
3.3.1 DEMOGRAPHICS
Note: Since full 2020 Census Data was not available at the time of this plan, the remainder of the section summarizes the most up-to-date information for Monterey County according to the 2015-2019 American Community Survey (ACS) performed by the US Census Bureau, except where noted.
The median age of Monterey County residents is 34.4 years. Monterey County’s population is relatively young with 50.8% of residents under the age of 34. The next largest age group consists of adults between the ages of 35-59 comprising 30.7% of the population. Older adults ages 60+ make up about 13% of the population.
The gender makeup of the county is 51% male and 49% female. The racial makeup is approximately 53.3% White, 5.6% Asian, 2.6% Black or African American, 0.7% American Indian or Alaskan Native, and 0.5% Native Hawaiian and other Pacific Islander, and 4.3% from two or more races. Hispanic or Latino of any race makes up 58.7% of the county population.
Figure 3-2 summarizes the demographics of the population of Monterey County.
Figure 3-2
Monterey County Demographics
Figure 3-2: Monterey County Demographics
1 California Department of Finance, Population Projections
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There are approximately 127,155 households in Monterey County with an average household size of 3.3 persons. Married couples make up 52.5% of households and cohabiting couple comprise 7.8% of households. 15.3% of households have a male householder and 24.4% have a female householder, with no spouse/partner present.
78% of Monterey County residents are US citizens, which is lower than the national average of 93% and the state average of 87%. In 2017, the percentage of US citizens in Monterey County was 77.4%, meaning that the rate of citizenship has been increasing. Immigrants comprise about 30% of the total population, and at 21%, Monterey County has the highest percentage of non-citizens of any county in California. The County’s immigrant population, including undocumented immigrants, is a critical component of the local labor force, especially for the agriculture, and hospitality industries.
3.3.2 INCOME
Per capita income in Monterey County continues to be at the low end of the spectrum in comparison to the statewide average and nearby counties. In 2019, the County had a per capita personal income of $30,073 and a median household income of $71,015 annually. 81.9% of households received earnings exclusive of social security and retirement income, with an average income amount of $91,308. 30% of households received Social Security with the average income amount of $19,147 and 17.6% of households received retirement income with the average income of $37,254. These income sources are not mutually exclusive; that is, some households received income from more than one source.
3.3.3 EDUCATION
The education system in Monterey County primarily consists of a public school system headed by the Monterey County Office of Education (MCOE). MCOE was established more than 150 years ago by California’s Constitution and supports 24 school districts, two community colleges, and a state university. Data from the California Department of Education 2 indicates that in
Monterey County, 2019-20 enrollment in K-12 Public Schools was 77,387. After experiencing continuous declines in enrollment growth, the County’s K-12 enrollment began growing steadily in 2009 and has grown by 6.7% since then. However, in 2020 enrollment declined by 0.7% from the previous year. Between 2019 and 2020, Monterey County's high school graduation rate increased from 83.5% to 84.5%. In 2017-18, the college going rate was 67.7% compared to the State’s rate of 65.2%.
Higher Education and Research Institutions
Approximately 71.5% of people 25 years and over in Monterey County have graduated from high school and 24.7% had a bachelor's degree or higher.
2 California Department of Education, DataQuest
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Monterey County is home to a range of institutions of higher learning, both public and private, large, and small, general, and highly focused institutions, particularly related to marine research. The higher education and research institutions located in the County contribute to the local economy, directly employing more than 15,000 faculty, staff, and researchers.
Institutions in the County include:
• Brandman University
• Cabrillo College
• California Department of Fish & Wildlife (CDFW) Marine Region • California State University, Monterey Bay
• Central Coast College
• Defense Language Institute, Foreign Language Center
• Defense Manpower Data Center
• Elkhorn Slough National Estuarine Research Reserve
• Fleet Numerical Meteorology and Oceanography Center, US Navy • Golden Gate University
• Hartnell College
• Hopkins Marine Station of Stanford University
• Middlebury Institute of International Studies at Monterey • Monterey Bay Aquarium
• Monterey Bay Aquarium Research Institute (MBARI)
• Monterey College of Law
• Monterey Bay National Marine Sanctuary
• Monterey Peninsula College
• Moss Landing Marine Lab, California State University (7 campuses) • Pacific Fisheries Environmental Laboratory (NOAA)
• Panetta Institute for Public Policy
• National Weather Service (NOAA)
• Naval Postgraduate School
• Naval Research Laboratory
• US Geological Survey (USGS), Pacific Science Center
• University of California, Santa Cruz (UCSC)
3.4 HOUSING
Of the approximately 141,820 housing units in Monterey County, an estimated 90% are occupied, and 10% are vacant. Of the total housing units, 69% are in single-unit structures, 27% are in multi-unit structures, and 5% are mobile homes. 23.5% of housing units were built since 1990, and 28% were built prior to 1960. Of all occupied housing units, about 50% were moved into since 2010. Of the 127,155 occupied housing units, 51%, 64,900 units are owner-occupied COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 3-12 COMMUNITY PROFILE
and 49%, 62,255 units are renter occupied. This percentage of owner-occupation is lower than the national average of 64%, but similar to the state average of 54.8%. Table 3-2 shows the ownership percentage in Monterey County compared its parent and neighboring geographies.
Table 3-2: Home Ownership in Monterey County Compared to Other Jurisdictions Table 3-2
Home Ownership in Monterey County Compared to Other Jurisdictions Jurisdiction Owner-Occupied Renter-Occupied
Monterey County, California 51% 49%
United States 64% 36%
California 54.8% 45.2%
Fresno County, California 53.3% 46.7%
Kings County, California 52.3% 47.7%
San Benito County, California 63.7% 36.3%
San Luis Obispo County, California 61.6% 38.4%
Santa Cruz County, California 60.1% 39.9%
Source: 2015-2019 American Community Survey 5-Year Date Profile The median housing value of owner-occupied units is $516,600 and 67% of owner-occupied units had a mortgage. The median monthly housing costs for mortgaged owners was $2,265 and $593 for non-mortgaged owners, 31% of owners with mortgages and 12% of owners without mortgages spent 35% or more of household income on housing costs. The median gross rent in the County was $1,495 and 44.5% of renters spent 35% or more of household income on rent. About 88.2% of County residents were living in the same residence one year earlier. 5.8% of people had moved during the past year from another residence in the County,
3.3% from another county in California, 1.9% from another state, and 0.8% from abroad.
Geographic Mobility
Monterey County is connected to the north and south by US Highway 101 and State Route 1 and is connected to the Central Valley by State Routes 156 and 198. State Route 68 connects Salinas with the Monterey Peninsula and State Route 145 provides access to the Pinnacles National Recreation Area. The Monterey Peninsula Airport provides regular flights to San Francisco, Los Angeles, Phoenix, Denver, and Las Vegas. Four carriers currently provide service from Monterey and provide 40 flights in and out daily. AMTRAK serves Monterey County daily north and south with a station in Salinas. The County is also served by Greyhound Bus Lines.
3.5 LOCAL ECONOMY
Monterey County’s economy is primarily based upon tourism in the coastal regions and agriculture in the Salinas Valley. In 2019, The total GDP in Monterey County was approximately $24.5 billion. Of the sectors in Monterey County, Agriculture, Forestry, Fishing and Hunting contributed the largest portion of GDP, almost $5 billion. The next-largest contributions came COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 3-13 COMMUNITY PROFILE
from Real Estate and Rental and Leasing, about $3 billion, Public Administration, about $2.1 billion, and Health Care and Social Assistance, about $2 billion.
Agriculture
Monterey County is one of the nation’s top agricultural producers. Agriculture is the County’s largest sector in terms of economic output and employment. As such, it represents a vital link to both the County’s cultural past and competitive future. Agriculture touches nearly every facet of life in Monterey County. From lettuce in the Salinas Valley, artichokes in Castroville, berries in north Monterey County, or vineyards in the Carmel Valley, agriculture shapes County life. Monterey County is known as “The Salad Bowl of the World” and crops grown in the County supply large percentages of total national pounds produced each year: 61% of leaf lettuce, 57% of celery, 56% of head lettuce, 48% of broccoli, 38% of spinach, 30% of cauliflower, 28% of strawberries, and 3.6% of wine grapes. Monterey County farmers are among the most productive and efficient in the world, growing more than 150 crops. 3 In 2019, Monterey County agriculture accounted for a production value of over $4.4 billion, which was 3.6% over the previous year. Agriculture contributes a total of $11.7 billion in economic output. The $11.7 billion in economic output consists of $7.4 billion in direct economic output and $4.3 billion in additional economic output in the form of multiplier effects, over $31 million per day. Local agriculture accounts for more than 63,921 jobs in Monterey County with 57,503 being direct employees and 6,417 additional jobs made possible through expenditures by agricultural companies and their employees. One in five jobs in Monterey County directly attributable to the agricultural industry. 4 Tourism & Hospitality
Monterey County has long been a tourist destination attracting nearly 4.6 million visitors annually. The County has a worldwide reputation with widely recognized destinations such as Big Sur, Pebble Beach, Carmel-by-the-Sea, and Monterey – and attractions such as Monterey Bay Aquarium, National Steinbeck Center, 17-Mile Drive, Cannery Row, Fisherman’s Wharf, Pinnacles National Park, and the Monterey Wine Country. Tourism spending accounts for approximately $3 billion annually, supporting 27,000 jobs and generating $153 million in local tax revenue.
5 Visitors enjoy a wide variety of recreational activities including golf, beaches, scuba diving, sailing, kayaking, whale watching, fishing, camping, horseback riding, skydiving, hiking, biking, art galleries, exhibits, music, and theatre. Nearly 300 special events take place in Monterey County annually, including AT&T Pebble Beach Pro-Am Golf Tournament, Monterey Jazz Festival, races at WeatherTech Raceway Laguna Seca, Concours d'Elegance, Big Sur Marathon and other food, wine, cultural and family festivals.
3 Facts, Figures & FAQs, Monterey County Farm Bureau
4 Economic Contributions of Monterey County Agriculture, Agricultural Commissioner’s Office (June 2020) 5 2020-2021 Annual Report, Monterey County Convention & Visitors Bureau COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 3-14 COMMUNITY PROFILE
3.6 EMPLOYMENT
Monterey County’s civilian labor force includes approximately 197,404 persons, or about 45% of the County’s total population. 76.4% of the civilian workforce is private wage and salary workers; 15.2% are government workers; and 8.1% are self-employed in their own businesses.
Monterey County’s annual unemployment rate in 2020 was 10.8%. The most common industries in Monterey County, by number of employees, are Agriculture, Forestry, Fishing, Mining & Hunting (55,033 workers), Health Care & Social Assistance (22,297 workers), and Accommodation & Food Services (21,287 workers). Compared to other counties, Monterey County, has an unusually high number of Agriculture, Forestry, Fishing & Hunting industry (20x higher than expected). Sectors with the highest average wages per worker are Utilities ($123,326), Mining, Quarrying, and Oil and Gas Extraction ($103,601), and Finance and Insurance ($87,368). 6 Figure 3-3 shows the breakdown of the labor force by industry.
Figure 3-3
Monterey County Labor Force Breakdown, By Industry
Figure 3-3: Monterey County Labor Force Breakdown, By Industry Source: Monterey County Workforce Development Board
Compared to the national average, Monterey County has an unusually high number of residents working in Farming, Fishing, & Forestry Occupations (32 times higher than expected), Building & Grounds Cleaning & Maintenance Occupations, and Food Preparation & Serving Related Occupations.
According to the State of California Employment Development Department’s Labor Market Division, Monterey County’s local economic strength lies in occupations that generally pay lower wages, explaining why the per capita income levels are relatively low compared to nearby counties. In Monterey County, 18% of the labor force consists of occupations in Farming,
6 Economic Overview: Monterey County, Monterey County Workforce Development Board (November 30, 2020)
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Fishing, and Forestry. In the first quarter of 2020, the mean hourly wage was $15.46 per hour.
The second highest occupational category is Office and Administrative Support, accounting for 10% of the workforce with a mean wage of $22.36 per hour. Food Preparation and Serving- Related occupations represent the third largest share of Monterey County’s employment, with 10% and a mean wage of $15.37 per hour. The top three occupations in Monterey County represent 38% of all employment.
Monterey County continues its efforts to attract more highly skilled jobs to the local economy by encouraging its residents to seek higher educational opportunities that will in turn create a more highly skilled labor force. Occupations in with the highest average wages per worker are Healthcare Practitioners and Technical Occupations ($121,200), Management Occupations ($119,400), and Legal Occupations ($116,500). Inflow/Outflow job data from 2018 indicates the majority of employees (113,458) live and work in Monterey County. Figure 3-4 summarizes inflow/outflow job data for Monterey County.
Figure 3-4
Inflow/Outflow Job Counts in 2018 for Monterey County
Figure 3-4: Inflow/ Outflow Job Counts in 2018 for Monterey County
Source: United States Census Bureau, Job-to-Job Flows (J2J) Recent forecasts suggest that agriculture will continue to provide the greatest number of new jobs, but post-secondary education and specialized business services, both key components of the expanding technology sector of the County, will show the highest percentage growth over the next several years. Table 3-3 summarizes projected change in number of jobs in 2026 based on occupation from a 2016 baseline.
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Table 3-3: Projected Change in Occupation in Monterey County Table 3-3
Projected Change in Occupation in Monterey County
Occupation 2016
Employment
2026
Employment
Percent
Change
Management Occupations 14,280 15,920 +11.5%
Business & Financial Operations Occupations 5,520 6,020 +9.1% Computer & Mathematical Occupations 2,080 2,310 +11.1%
Architecture & Engineering Occupations 1,150 1,270 +10.4% Life, Physical & Social Science Occupations 1,620 1,760 +8.6% Community & Social Service Occupations 2,230 2,590 +16.1% Legal Occupations 890 970 +9%
Education, Training & Library Occupations 13,240 15,130 +14.3% Arts, Design, Entertainment, Sports, & Media Occupations 2,350 2,570 +9.4% Healthcare Practitioners & Technical Occupations 6,990 8,310 +18.9% Healthcare Support Occupations 3,050 3,630 +19%
Protective Service Occupations 4,450 270 -4%
Food Preparation & Serving Related Occupations 17,200 19,340 +12.4% Building/Grounds Cleaning & Maintenance Occupations 7,970 8,970 +12.5% Personal Care & Service Occupations 8,260 10,520 +27.4% Sales & Related Occupations 16,080 16,840 +4.7%
Office & Administrative Support Occupations 20,990 21,710 +3.4% Farming, Fishing & Forestry Occupations 45,580 55,590 +22% Construction & Extraction Occupations 6,340 7,420 +17%
Installation, Maintenance & Repair Occupations 6,870 7,490 +9% Production Occupations 5,200 5,590 +7.5%
Transportation & Material Moving Occupations 11,120 12,560 +12.9% Total 203,460 226,780
Source: California Employment Development Department
3.7 SOCIAL VULNERABILITY
Social vulnerability refers to the resilience of communities when confronted by external stresses, including natural or human-caused disasters. Characteristics of a population can serve as an important gauge of everything from evacuation compliance to successful long-term recovery, therefore reducing social vulnerability can decrease both human suffering and economic loss. Geographic patterns of potential population vulnerability to disaster can be used to inform mitigation, preparedness, response, and recovery. Considering social vulnerability is an important step in establishing a Whole Community approach to emergency management and hazard mitigation.
Hazard exposure alone does not fully explain disaster resilience; characteristics including age, ethnicity, race, income, household structure, language, employment, home & car ownership, COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 3-17 COMMUNITY PROFILE
health, population density, insurance, and citizenship, can also impact how well a person manages hazard risks. For the purposes of this plan, the CDC’s Social Vulnerability Index (2016), was used to assess the vulnerability of the community. The Index uses US Census data to determine the social vulnerability of census tracts. The Index ranks each tract on 15 social factors, including poverty, lack of vehicle access, and crowded housing. Each tract receives an overall ranking. Figure 3-5 shows overall Social Vulnerability by census tract in the County.
Figure 3-5
Overall Social Vulnerability in Monterey County
Figure 3-5: Overall Social Vulnerability Index in Monterey County The index also groups tracts into four related themes and ranks them by theme. The four themes used by the CDC Social Vulnerability Index include:
• Socioeconomic Status • Minority Status and Language
• Household Composition and Disability • Housing Type and Transportation
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3.7.1 SOCIOECONOMIC STATUS
The Socioeconomic Status Theme consists of income, poverty, employment, and education variables. Economically disadvantaged populations are disproportionately affected by disasters and are less likely to have the income or assets needed to prepare for a possible disaster, respond to, or to recover after a disaster. Although the monetary value of their property may be less than that of other households, it likely represents a larger proportion of total household assets. For these households, lost property is proportionately more expensive to replace, especially without homeowner’s or renter’s insurance. Figure 3-6 shows overall ranking by census tract on the Social Vulnerability Index Socioeconomic Status Theme in Monterey County.
Figure 3-6
CDC Social Vulnerability Index: Socioeconomic Status in Monterey County
Figure 3-6: CDC Social Vulnerability Index: Socioeconomic Status Approximately 13.1% of people in the County are in poverty; about the same rate as California (13.4%) and the in US (13.1%). 9.6% of families are below the poverty line. 19.4% of children under 18 are below the poverty level, compared with 8% of people 65 years old and over. The largest demographic living in poverty is Females, with no spouse and a child under 18 (35%).
The most common racial or ethnic group living below the poverty line in the County is Hispanic, followed by White and Other.
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Approximately, 2% of residents received cash public assistance benefits, averaging $4,533 annually. Monterey County has the highest yearly enrollment when compared to its neighboring counties (1,915 participants in 2018-2019) in CalWORKS, which provides financial assistance to families. About 7% of residents received Supplemental Nutrition Assistance Program (SNAP) benefits. Monterey County has 18,961 housesholds participating, in CalFresh, which supplements the food budget of low-income households to meet their nutritional needs.
3.7.2 HOUSEHOLD COMPOSITION AND DISABILITY
The Household Composition and Disability Theme is composed of age, single parenting, and disability variables. Household composition is defined here to include dependent children less than 18 years of age, persons aged 65 years and older, and single-parent households. Also included are people with disabilities. People in any of these categories are likelier to require financial support, transportation, medical care, or assistance during disasters. Children and elders are the most vulnerable groups in disasters. Children, especially younger children, cannot protect themselves during a disaster because they lack the needed resources and knowledge to effectively cope with the situation. Figure 3-7 shows overall ranking by census tract on the CDC Social Vulnerability Index Household Composition and Disability Theme in Monterey County.
Figure 3-7
CDC Social Vulnerability Index: Household Composition and Disability in Monterey County
Figure 3-7: CDC Social Vulnerability Index: Household Composition and Disability
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An estimated 8.8% of residents in Monterey County has a disability. 30.6% of residents 65 years of age and older had a disability. Table 3-4 summarizes the percentage of the population in Monterey County who have a disability by age group and type of disability.
Table 3-4: Percent of Noninstitutionalized County Residents with a Disability by Age Table 3-4
Percent of Noninstitutionalized Monterey County Residents with a Disability by Age Group Type of Disability Under 18 18 to 64 Years 65+ Years Total With a hearing difficulty 0.5% 1.4% 13.1% 2.7%
With a vision difficulty 0.6% 1.4% 4.8% 1.6%
With a cognitive difficulty 3.0% 2.8% 8.2% 3.6%
With an ambulatory difficulty 0.6% 2.9% 18.7% 4.7%
With a self-care difficulty 1.0% 1.3% 8.2% 2.2%
With an independent living difficulty n/a 2.5% 13.2% 4.5% Total Persons with Disabilities 3.1% 6.6% 30.6% 8.8%
Additionally, many residents suffer from a chronic health condition. Table 3-5 summarize age- adjusted prevalence rates from chronic conditions in Monterey County.
Table 3-5: Prevalence of Chronic Health Conditions of Adults Aged 18 and Over Table 3-5
Prevalence of Chronic Health Conditions of Adults Aged 18 and Over 7 Health Condition Age-Adjusted Prevalence Rate
Arthritis 21.6%
High Blood Pressure 28.8%
Cancer1 5.7%
Asthma 9.2%
Coronary Heart Disease 6%
Chronic Obstructive Pulmonary Disease 6%
Diabetes 10.8%
High Cholesterol2 29.6%
Chronic Kidney Disease 3.1%
1Excludes skin cancer
2Among adults who have been screened in the past 5 years Source: Centers for Disease Control, PLACES: Local Data for Better Health, County Data, 2020
3.7.3 MINORITY STATUS AND LANGUAGE
The Minority Status and Language Theme is composed of race, ethnicity, and English language proficiency variables. The social and economic marginalization of certain racial and ethnic groups has rendered these populations more vulnerable at all stages of disaster. African Americans; Native Americans; and populations of Asian, Pacific Islander, or Hispanic origin are correlated with higher vulnerability rates. In recent decades, the numbers of persons immigrating to the United States from Latin America and Asia have substantially increased.
Many immigrants are not fluent in English, and literacy rates for some groups are lower. To the
7 Centers for Disease Control, PLACES: Local Data for Better Health, County Data, 2020 COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 3-21 COMMUNITY PROFILE
degree that immigrants have limited English proficiency, disaster communication is made increasingly difficult. Figure 3-8 shows overall ranking by census tract on the CDC Social Vulnerability Index Minority Status and Language Theme in Monterey County.
Figure 3-8
CDC Social Vulnerability Index: Minority Status and Language Theme in Monterey County
Figure 3-8: CDC Social Vulnerability Index: Minority Status and Language As of 2015, data from the Department of Justice indicates that 109,286 people, 28.2% of residents in Monterey County have limited English proficiency. 91% of the population with limited English proficiency speak Spanish. The next most common language spoken was Tagalog, account for 2.1% of the limited English proficiency population.
3.7.4 HOUSING AND TRANSPORTATION
The Housing and Transportation Theme is composed of housing structure, crowding, and vehicle access variables. Housing quality is an important factor in evaluating disaster vulnerability. It is closely tied to personal wealth; that is, poor people often live in more poorly constructed houses or mobile homes that are especially vulnerable to strong storms or
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earthquakes. Populations residing in group quarters such as college dormitories, farm workers’ dormitories, psychiatric institutions, and prisons also present special concerns during evacuation. Residents of nursing homes and long-term care facilities are especially vulnerable because of their need for specific and limited resources.
On average, farmworker incomes are less than half of the area median household income.
Some housing requirements can pose a particular challenge to farmworkers. For example, farmworkers may have difficulty establishing good credit or demonstrating long-term residency, both of which are often standard requirements in the private rental-housing market.
Substandard and structurally deficient conditions are common in farmworker housing; conditions that are often worsened by crowding or lack of affordability. The lack of an adequate, affordable housing supply forces farmworkers to live in overcrowded and unsafe housing or to seek housing in garages or other substandard structures that sometimes do not provide basic shelter or sanitation. Figure 3-9 shows overall ranking by census tract on the CDC Social Vulnerability Index Housing and Transportation Theme in Monterey County.
Figure 3-9
CDC Social Vulnerability Index: Housing and Transportation Theme in Monterey County
Figure 3-9: CDC Social Vulnerability Index: Housing and Transportation
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Homeless populations are also vulnerable during disasters. As of the last comprehensive count in 2019 8, there were 2,422 homeless people in Monterey County. As homeless populations can be difficult to count accurately this number is most likely underestimated. Most of the homeless population, 76% is unsheltered, spending their nights outdoors, primarily in the streets or parks (22%), in their vehicle (19%), or in a tent (18%). Men (65%) are disproportionately represented in the County’s homeless population, as are Black/African American residents (25% of the homeless population, 3% of the County population). Over half of homeless survey respondents, 58%, have at least one disabling condition. 44% suffer from depression, 45% abuse drugs or alcohol, 27% have physical disabilities, 25% suffer from chronic health problems, and 23% have post-traumatic stress disorder.
3.8 LAND USE AND DEVELOPMENT TRENDS
Monterey County has a total area of 3,771 square miles, of which 13% is water. As seen in Table 3-6, Land cover data indicates that the largest land use in Monterey County is shrubland, followed by grasslands and forest land. The majority of developed land consists of low-intensity development.
Table 3-6: Land Cover in Monterey County 2018 Statistics
The County and its municipal planning partners all adopt General Plans, which serve as blueprints for establishing long-range development policies, as directed with California’s General Planning Law. Decisions on land use will be governed by these plans. This hazard mitigation plan will work together with the General Plans to support wise land use in the future by providing vital information on the risk associated with natural hazards in the planning area. A
8 Monterey County Homeless Census & Survey Comprehensive Report (2019) Table 3-6
Land Cover Monterey County: 2018 Statistics
Land Cover Type1 Percent
Crops2 5.3%
Forest3 22.3%
Wetlands 1.5%
High Intensity Developed 0.6%
Low Intensity Developed 5.6%
Grassland 24.9%
Shrubland 35.4%
Fallow 2.7%
Barren 1.7%
Source: CalLands, UC Agriculture and Natural Resources (2018) 1 Percentages recalculated based on acreage to exclude water 2 All crop categories combined (Alfalfa & hay, corn, cotton, fruit trees, grain crops, grapes, other tree crops, rice, tomatoes, vegetables & fruits, walnuts, winter wheat) 3 Includes deciduous, evergreen, and mixed forest
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General Plan provides a basis for private development proposals and public projects to remain consistent with existing city, regional and state policies. The General Plan is designed to help the County and participating jurisdictions address issues related to land use, circulation(traffic), housing, open space, conservation, noise, and safety. The Land Use portion of the plan helps guide the County and participating jurisdictions in determining the location of future development(s), to include possible future annexations for municipal jurisdictions. The Safety Element of the General Plan serves to decrease risk of impact from natural hazards.
Past development that most led to the highest increases in hazard vulnerability in the County happened many decades and even more than a century ago. The County and other participating jurisdictions are well aware of areas of increased hazard risk related to older development. More recently, development in the last few decades has occurred with less hazard risk because of existing overlay of Federal, State, and local regulations.
The Association of Monterey Bay Area Governments (AMBAG) estimates that to house the region’s expected population growth by 2040, an increase of approximately 24,000 housing units is needed in Monterey County. A large amount of the growth is expected to occur in South County and in the Cities of Marina and Seaside. 9 Future development may become constrained due to limited water sources, poor water quality, and geologic (landslide), fire, flood, and seismic hazards. In addition to local challenges, infrastructure problems affect entire regions.
All planning partners reviewed their General Plans under the capability assessments undertaken for this hazard mitigation plan. Deficiencies revealed by these reviews are identified as mitigation actions to decrease risks to move beyond past trends. Moreover, while past development has occurred in hazard areas to some degree, increasing hazard risks, development standards and performance measures, often times incorporated into specific plans, policy plans, and master plans, are employed to reduce risk. These development standards are continually improving and will continue to strengthen into the future.
The Safe Growth Survey,
10 a technique recommended by organizations such as the American Planning Association (APA) and FEMA, 11 was used to evaluate the extent to which each local jurisdiction in Monterey County is positioned to grow safely relative to its natural hazards. The survey was used to gain an understanding of individual jurisdiction’s land use and devolvement trends and how various comprehensive plans, capital improvement plans, and zoning and subdivision ordinances may allow growth in hazardous areas. The Safe Growth Survey was used as part of the 2013-2014 MJHMP Plan update, which allowed the survey results to be compared over time, in order to measure progress. The results indicate that municipal jurisdictions in the County are continuing to maintain the level of safe growth established in 2016. More information on the Safe Growth Survey is included in Section 20.2, Safe Growth Survey. Specific
9 2018 Regional Growth Forecast, Association of Monterey Bay Area Governments (June 2018) 10 Safe Growth Audits, David R. Godschalk, FAICP (October 2009) 11 Local Mitigation Planning Handbook, Worksheet 4.2: Safe Growth Audit, FEMA (March 2013) COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 3-25 COMMUNITY PROFILE
land use and development trends, along with the Safe Growth Survey results for each participating municipal jurisdiction are included in their respective Annex in Volume 2.
Water Availability
In the coastal regions of California, access to water is a barrier to new development. Access to water is a primary constraint to development on the Monterey Peninsula. Water is supplied to most of the Monterey Peninsula through wells in Carmel Valley, dams, and a well drawing from the Seaside Aquifer. However, since 2020 a portion of the Monterey Peninsula's potable water supply has come from indirect potable reuse via the Pure Water Monterey Groundwater Replenishment Project, an effort lead by Monterey One Water. The Monterey Peninsula Water Management District has established water allocations for jurisdictions within its district and communities have distributed most of the available allocations. As a result, new development must either provide another water source such as a well or enter a waitlist for future allocations.
Fort Ord Reuse
Fort Ord was a major US Army base which closed in 1994. The former Fort Ord Military Base is located on the California coastline near the Monterey Peninsula consisting of 45 square miles and covering over 28,000 acres of land. The Fort Ord Reuse Authority (FORA), a large multi- governmental body composed of elected officials at the local, state, and federal levels, was created by the California State Legislature in 1994 with the legislatively mandated mission of overseeing replacement land use, removing physical barriers to reuse, financing and constructing major components of the required infrastructure and protecting identified environmental reserves.
The property was divided among the City of Seaside, City of Marina, and unincorporated Monterey County. This reuse has resulted in the expanding of the cities of Marina, Del Rey Oaks, and Seaside, and adding area to be developed by Monterey County. 69% of the total acreage has been dedicated to recreational/open space. About 1,000 acres were used to create the Fort Ord Dunes State Park and approximately 15,000 acres were dedicated by President Obama for the Fort Ord National Monument. The Fort Ord National Monument consists of nearly 23 square miles of undeveloped natural wildlands and is open to the public and managed by the US Department of the Interior, Bureau of Land Management.
Many other areas have been converted from military to civilian land uses under the direction of FORA. While many old military buildings and infrastructure remain abandoned, many others have been demolished. Notable developments include the cleanup of Army munitions from thousands of acres of land, the California State University Monterey Bay (CSUMB) campus, the UC-Santa Cruz Monterey Bay Education, Science and Technology Center (MBEST), the Veterans Transition Center, residential subdivisions, shopping centers, health clinics, new military facilities, and a nature preserve. FORA legislatively terminated on June 30, 2020. The responsibility for the area and undeveloped land now falls to the individual jurisdictions of Seaside, Marina, Del Rey Oaks, Marina Coast Water District, and the Monterey County.
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PART | B
B
PART B: HAZARD PROFILES AND
RISK ASSESSMENT
THIS PART IDENTIFIES, PROFILES, AND ASSESSES THE HAZARDS THAT COULD AFFECT MONTEREY COUNTY. IT CONSISTS OF THE FOLLOWING SECTIONS:
4. RISK ASSESSMENT METHODS 12. HUMAN CAUSED HAZARDS
5. AGRICULTURAL EMERGENCIES 13. PUBLIC HEALTH HAZARDS
6. COASTAL EROSION 14. SEVERE WEATHER
7. DAM & LEVEE FAILURE 15. SLOPE FAILURE
8. DROUGHT 16. TSUNAMI
9. EARTHQUAKE 17. UTILITY INTERRUPTION
10. FLOODING 18. WILDFIRE
11. HAZARDOUS MATERIALS INCIDENT 19. CLIMATE CHANGE
COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PART | B
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4. RISK ASSESSMENT METHODS
As defined by the Federal Emergency Management Agency (FEMA), risk is the potential for damage, loss, or other impacts created by the interaction of hazards with community assets.
The risk assessment process measures the potential loss to a community, including loss of life, personal injury, property damage, and economic injury resulting from a hazard event. This information provides a framework for a community to develop and prioritize mitigation strategies and plans to help reduce both the risk and vulnerability from future hazard events.
The FEMA Local Mitigation Planning Handbook identifies four steps for conducting a risk assessment:
1. Identify & Describe Hazards
2. Identify Community Assets
3. Analyze Risks
4. Summarize Vulnerability
The risk assessment for this hazard mitigation plan update evaluates the risk of hazards prevalent in Monterey County and meets requirements of the Disaster Mitigation Act and 44 CFR, Section 201.6(c)(2).
4.1 HAZARD IDENTIFICATION
The first step in the planning process was to identify the threats and hazards of concern in Monterey County, based on a combination of experience, forecasting, subject matter expertise,
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and other available resources. This supported the development of a list of threats and hazards that could affect the community. Hazards were categorized as follows:
• Natural hazards are naturally occurring physical phenomena caused either by rapid or slow onset events which can be geophysical (earthquakes, landslides, tsunamis, and volcanic activity), hydrological (avalanches and floods), climatological (extreme temperatures, drought, and wildfires), meteorological (cyclones and storms/wave surges), or biological (disease epidemics and insect/animal plagues). • Technological hazards are generally accidental or result from events with unintended consequences (for example, an accidental hazardous materials release). • Human Caused Hazards result from the intentional actions of an adversary, such as a threatened or actual terrorism, chemical attack, biological attack, or cyber incident.
The Steering Committee considered the full range of hazards that could affect the County and then listed hazards that present the greatest concern. The process incorporated a review of state and local hazard planning documents, as well as information on the frequency of, magnitude of, and costs associated with hazards that have struck or could strike the County.
Anecdotal information regarding natural hazards and the perceived vulnerability of the County’s assets to them was also used. Table 4-1 summarizes the hazards of concern this plan will address.
Table 4-1: Hazards of Concern
Table 4-1
Hazards of Concern
Hazard Reason for Inclusion
Agricultural
Emergencies
Agriculture is an economic driver in the County and is at risk to many hazards such as insects, weeds, wildfire, and severe weather.
Coastal Erosion
Parts of the County are located on the Ocean and are subject to erosion risk. Coastal erosion can create hazardous conditions, threatens dune habitat, and poses a threat to the agriculture and tourism industries. Sea level rise is likely to exacerbate erosion risk.
Dam & Levee Failure
Several large and aging dams are in the County, in addition to many miles of levees. Dam failure can be catastrophic to all life and property downstream.
Drought
Droughts are a serious threat and could have devastating impacts on agriculture. Previous droughts have caused major economic damage to the agricultural industry and prolonged periods of drought can reduce water availability and increase water prices.
Earthquake
Several active faults, including the San Andreas Fault, run through the County. Due to the location of population centers and building history, any earthquake will likely have significant impacts on people, property, and critical infrastructure. An earthquake could also trigger other natural hazard events such as dam failures and landslides, which could severely impact the County.
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Table 4-1
Hazards of Concern
Hazard Reason for Inclusion
Flooding
Flooding is a major hazard and is associated with many of the largest and most damaging historical hazard events. The history of flooding is associated with coastal storms, heavy rainfall, flash flooding, and run-off. Increased impervious surfaces, the channelization of streams, and increased development in floodplains has resulted in intensified flood flows and more property and lives at risk.
Coastal Flooding Coastal flooding is generally associated with winter storms, high tides, and strong winds and is a significant hazard on the coastline.
Riverine Flooding Riverine flooding, notably along the Salinas, Carmel, and Pajaro Rivers, has caused damage in the County.
Flash Flooding Flash flooding occurs quickly with little to no warning and can cause serious damage in the County.
Localized Stormwater
Flooding
Drainage systems in the County have a finite capacity and prolonged heavy rainfall has contributed to flooding in more urbanized areas.
Hazardous Materials
Incidents
The County contains large industrial facilities, major transportation routes, agricultural operations, harbors, pipelines, and oil fields, all of which have the potential to cause a hazardous materials release.
Human Caused-Hazards
Although not required, human-caused hazards were included since preparation for them involves many of the same resources as a natural hazard. The likelihood of these hazard is greater than that of several of the natural hazards identified in this Plan.
Cyber-Attack
The spectrum of cyber-risks is limitless, with threats having a wide range of effects. Cyber-attacks can originate from any computer in the world and effect any system that is connected to the Internet.
Targeted Violence Mass-casualty incidents (MCIs) and active shooters can cause loss of life serious injuries, and associated property damage.
Terrorism
Terrorism can cause loss of life, widespread illness and injury, the destruction of property, the displacement of large numbers of people, and devastating economic losses.
Mass Migration Population migration of large scales can lead to resource pressures and can exacerbate existing instability.
Public Health Hazards
All of the County is susceptible to public health hazards. A large disease outbreak could have devastating effects on the population.
Health hazards can also have large economic effects and complicate response efforts to other natural hazard events.
Epidemic Due to increased air travel and growing population, the probability and threat of a communicable disease outbreak is growing.
Pandemic
While the probability of a major infectious disease pandemic is relatively low, it can have catastrophic social and economic consequences, as seen during the COVID-19 pandemic.
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Table 4-1
Hazards of Concern
Hazard Reason for Inclusion
Severe Weather
Severe weather has previously caused damage in Monterey County.
Due to the size of the County and changes in elevation and climate, weather conditions and their impacts can vary greatly. Severe weather events are also associated with a variety of secondary hazards, which have the potential to greatly impact the County.
Severe Winter Storms
Severe winter storms have caused damage in the County and can lead to immobility and loss of utilities. Heavy rain can have significant impacts, including flash flooding and mudslides.
Extreme Cold & Freeze
Extreme cold and freeze events have impacted the County. Freeze can have a devastating effect on agriculture. Prolonged exposure to cold can cause frostbite or hypothermia and can be life-threatening.
Windstorms
Windstorms are a frequent problem in the County and have been associated with injuries and fatalities. Windstorms can topple trees and cause damage to utilities and critical facilities.
Extreme Heat Extreme heat has caused fatalities in the County and is associated with a variety of health-related issues.
Sea Level Rise
Rising sea levels will increase the likelihood and intensity of floods., as well as lead to increased coastal and fluvial flooding, increased tidal inundation, coastal erosion, tsunami inundation, seawater intrusion, and worsened storm surge. (Profiled in Climate Change) Slope Failure
The County is vulnerable to slope instability, especially after prolonged rainfalls and in areas recently burned by wildfires. Slope failure is a common occurrence and has caused damage to homes, public facilities, and roads. In Big Sur, landslides have caused millions of dollars in damage and have led to lengthy closures of Highway 1.
Tsunami Several areas of the County are located in mapped tsunami inundation zones. Tsunamis are a threat to life and property.
Utility Interruption
Equipment failures and electrical infrastructure igniting wildfires has resulted in blackouts and power shutoffs throughout the County.
Loss of power for more than a few hours can result in large economic losses and have large effects on vulnerable populations.
Space Weather
Space weather can cause damage to critical infrastructure, especially the electric grid. The effects can be far-reaching, as virtually all infrastructure and services depend on the electric power grid.
Wildfire
The geography, terrain, weather patterns and vegetation in the County provide ideal conditions for recurring wildfires and rapid spread. Past wildfires have caused damage to critical infrastructure, property, and the environment, and have led to injuries and loss of life. The County is likely to face a wildfire threat each and every year and can expect a large fire to occur every few years.
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In addition to the hazards listed above, climate change was assessed as both a hazard and as exacerbating other hazards profiled in this Plan. Sea level rise risk is profiled within the climate change section, in addition to the increased risk of the following hazards:
• Agricultural Emergencies- The Salinas Valley is one of the most vulnerable agricultural regions to climate change. The amounts, forms, and distribution of precipitation, as well as the increased frequency and intensity of climate extremes, will affect water availability as well as pests, crop yields, and the length of the growing season. • Dam & Levee Failure- Dams and levees are designed partly based on assumptions about a river’s flow behavior. Changes in weather patterns can have significant effects on the behavior of rivers and these changes could conceivably cause a dam or levee to lose some or all of its designed margin of safety.
• Drought- With a warmer climate, droughts could become more frequent, more severe, and longer lasting, thereby increasing their impact on the County. • Earthquake- The impacts of global climate change on earthquake probability are unknown, but secondary impacts of earthquakes could be magnified by climate change. • Flooding- Climate change is likely to exacerbate the intensity and magnitude of precipitation events, increasing the risk associated with flooding. High frequency flood events in particular will likely increase with a changing climate. • Human-Caused Hazards- Climate change could lead to increases in violence and cause increases in climate induced migration.
• Public Health Hazards- Rising temperatures and more extreme drought events could lead to increases in heat-related illness, as well as vector-borne and infectious diseases. • Severe Weather- Extreme heat waves are likely to increase in probability due to climate change. Atmospheric river events, the dominant driver of locally extreme rainfall events and associated flooding, are expected to increase under projected climate change. • Slope Failure- Climate change will likely affect storm patterns, the occurrence and duration of droughts, and the probability of wildfire, which are all factors that would increase the probability of landslide occurrence.
• Tsunami- It is unclear if climate change would increase the frequency of tsunamis, but when a tsunami occurs the effects of climate change could lead to more destructive waves and inundation areas would likely reach further than current mapping indicates. • Wildfire- Climate change has the potential to affect multiple elements of the wildfire system: fire behavior, ignitions, fire management, and vegetation fuels.
Excluded Hazards
Other hazards were noted by the Steering Committee and the public to potentially consider in the MJHMP update. Some of these hazards have the potential to do damage or harm but were determined to not have a significant enough effect, so they are not profiled further; in some cases, they are currently addressed in other planning mechanisms or have had limited historic impacts. Table 4-2 lists the hazards excluded from this Plan.
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Table 4-2: Excluded Hazards
Table 4-2
Excluded Hazards
Hazard Type Explanation
Avalanche Monterey County is not located in area prone to frequent or significant snowfall.
Blizzard Monterey County is not located in area prone to frequent or significant snowfall.
Cyclone No historic events have occurred in Monterey County.
Ice Storm The County does not reach temperatures low enough with enough frequency for an ice storm to pose a major threat.
Limnic Eruption No historic events have occurred in Monterey County.
Civil Unrest This is a risk in Monterey County but is more appropriately dealt with in other planning mechanisms.
Expansive Soils No historic events have occurred in Monterey County.
Glacier Movement/ Collapse There are no glaciers in Monterey County.
Human-Wildlife Conflicts This is a risk in Monterey County but is more appropriately dealt with in other planning mechanisms.
Hurricane No significant historic events have occurred in the County.
Maritime Incidents This is a risk in Monterey County but is more appropriately dealt with in other planning mechanisms.
Plane Crash This is a risk in Monterey County but is more appropriately dealt with in other planning mechanisms.
Sinkholes No significant historic events have occurred in the County.
Supply Chain Interruptions This is a risk in Monterey County but is more appropriately dealt with in other planning mechanisms.
Volcano Due to distance from volcanoes and the limited chance of an eruption, this hazard was not identified as a priority.
4.1.1 DISASTER DECLARATION HISTORY
One important consideration in identifying and prioritizing hazards is past major hazard events, especially those that triggered federal, state, or local disaster declarations. Most available information on major past hazard events comes from past disaster declarations. If a local government determines effects of an emergency are beyond the capability of local resources to mitigate effectively, the local government may proclaim a local emergency. Pursuant to California Government Code Section 8680.9, a local emergency is a condition of extreme peril to persons or property proclaimed as such by the governing body of the local agency affected by a natural or manmade disaster. The purpose of a local emergency proclamation is to provide extraordinary police powers, immunity for emergency actions, authorize issuance of orders and regulations, activate pre-established emergency provisions, and is a prerequisite for requesting state or federal assistance.
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Pursuant to California Government Code Section 8625, the Governor may proclaim a State of Emergency in an area affected by a disaster, when he is requested to do so by the governing body of the local agency affected, or he finds the local authority is inadequate to cope with the emergency. The California Disaster Assistance Act (CDAA) provides state financial assistance for recovery efforts to local governments after a state disaster has been declared.
If the severity and magnitude of an event surpasses the ability of the local and state government to respond and recover, the Governor can request federal assistance. Based on the Governor’s request, the President may declare that a major disaster or emergency exists, thus activating an array of Federal programs to assist in the response and recovery effort. There are two types of disaster declarations provided for in the Stafford Act: Emergency Declarations and Major Disaster Declarations. Both declaration types authorize the President to provide supplemental federal disaster assistance. However, the event related to the disaster declaration and type and amount of assistance differ.
• Emergency Declarations: An Emergency Declaration can be declared for any occasion or instance when the President determines federal assistance is needed. Emergency Declarations supplement State and local efforts in providing emergency services, or to lessen or avert the threat of a catastrophe in any part of the US. The total amount of assistance provided for a single emergency may not exceed $5 million. • Major Declaration: The President can declare a Major Disaster Declaration for any natural event, including any hurricane, tornado, storm, high water, wind-driven water, tidal wave, tsunami, earthquake, volcanic eruption, landslide, mudslide, snowstorm, or drought, or, regardless of cause, fire, flood, or explosion, that the President believes has caused damage of such severity that it is beyond the combined capabilities of state and local governments to respond. A major disaster declaration provides a wide range of federal assistance programs for individuals and public infrastructure, including funds for both emergency and permanent work.
Not all programs, however, are activated for every disaster. The determination of which programs are authorized is based the types of assistance specified and, on the needs, identified during Preliminary Damage Assessments. FEMA disaster assistance programs are as follows:
• Individual Assistance: Assistance to individuals and households • Public Assistance: Assistance to state and local governments for emergency work and the repair or replacement of disaster damaged facilities • Hazard Mitigation Assistance: Assistance to state and local governments for actions taken to prevent or reduce long term risk to life and property from natural hazards.
Additionally, the Disaster Mitigation Act of 2000 authorized the Fire Management Assistance Grant (FMAG) program, which provides for the mitigation, management, and control of fires that threaten such destruction as would constitute a major disaster. The purpose of FMAG is to provide supplemental federal assistance to states and local government to fight fires burning COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 4-8 RISK ASSESSMENT
on public (non-federal) or privately owned forest or grassland. A Local or State fire agency must request an FMAG through the Cal OES Fire and Rescue Branch or the California State Warning Center while the fire is burning uncontrolled. The federal government may also issue a disaster declaration through the US Department of Agriculture (USDA), and the Small Business Administration (SBA). The SBA can make federally subsidized loans to repair or replace homes, personal property or businesses that sustained damages not covered by insurance. The Secretary of Agriculture is authorized can declare a disaster to make emergency loans available to producers suffering losses in declared counties and in counties that are contiguous to a designated county.
As summarized in Table 4-3, since 1990, Monterey County has experienced a total of 55 emergencies, resulting in a local, state, or federal disaster declaration, 14 of which were major federally declared disasters. This information, coupled with local historical and anecdotal information, helped inform the hazard identification process.
Table 4-3: Disaster Proclamations and Declarations (1990- 2021) Table 4-3
Disaster Proclamations and Declarations (1990-2021)
Year Declaration Type Incident Type Description FEMA # CDAA # Local # 2021 State and Local
Emergency Drought Drought 2021 21-189
2021 State and Local
Emergency Severe Storms Severe Winter Storms, Flooding, Mudslides, and Erosion
2021 21-033
2020 Major Disaster Wildfire August 2020 Wildfires DR-4558 2020-06 2020 Local Emergency Wildfire Dolan Fire 20-283
2020 Fire Management Wildfire Carmel Fire FM-5333 2020-06 2020 Fire Management Wildfire River Fire FM-5329 2020-06 20-277 2020 Local Emergency Flood Salinas River Lagoon Flooding 20-309 2020 Major Disaster Public Health COVID-19 Pandemic DR-4482 2020-01 20-060 2019 Local Emergency Flood Carmel River & Lagoon Flooding 19-016 2019 State and Local
Emergency Flood Atmospheric River, Chualar Flash
Flood, and Carmel River Flooding
2020-05 19-943
2019 Local Emergency Utility
Interruption Public Safety Power Shutoff 19-383
2019 Major Disaster Severe Storms Late February 2019 Storms DR-4434 2019-03 2019 State and Local
Emergency Severe Storms Mid-February 2019 Atmospheric
River
2019-02 19-077
2019 Local Emergency Flood Salinas River Lagoon Flooding 19-022 2017 Major Disaster Severe Storms February 2017 Winter Storms DR-4308 2017-03 17-045 2017 Major Disaster Severe Storms January 2017 Winter Storms DR-4301 2017-01 17-008 2017 Local Emergency Flood Salinas River Lagoon Flooding 16-005 2016 Local Emergency Erosion Emergency Infrastructure Repair 16-089 2016 Local Emergency Flood Emergency Infrastructure Repair 16-324 2016 Fire Management Wildfire Soberanes Fire FM-5137
16-206
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Table 4-3
Disaster Proclamations and Declarations (1990-2021)
Year Declaration Type Incident Type Description FEMA # CDAA # Local # 2016 Local Emergency Severe Storms Severe Winter Storms 16-084 2015 Local Emergency Saltwater
Intrusion
Saltwater Intrusion and Inundation
at Moro Cojo Slough
15-122
2015 Local Emergency Wildfire Tassajara Fire 15-253
2014 Local Emergency Saltwater
Intrusion
Saltwater Intrusion and Inundation
at Moro Cojo Slough
14-299
2014 Local Emergency Wildfire Pfeiffer Fire 14-003
2012 Local Emergency Flood Salinas River Lagoon Flooding 12-386 2012 Local Emergency Flood Carmel River & Lagoon Flooding 12-027 2011 Major Disaster Tsunami March 2011 California Tsunami DR-1968 2011-02 2011 Local Emergency Debris Flow Highway 1 Failure and Closure 11-075 2010 Local Emergency Flood Carmel River & Lagoon Flooding 10-083 2010 Local Emergency Flood Carmel River & Lagoon Flooding 10-006 2009 Local Emergency Public Health Influenza A (H1N1) Virus Infection 09-319 2009 State and Local
Emergency Wildfire Gloria Fire 2009-06 09-376
2009 Local Emergency Hazmat Dayton Fire Explosion and
Hazardous Material Incident
09-741
2009 Local Emergency Flood Salinas River Lagoon Flooding 09-172 2009 Local Emergency Debris Flow Basin Complex Burn Scar Debris Flow
09-147
2009 Local Emergency Flood Carmel River & Lagoon Flooding 09-148 2009 Local Emergency Public Health Human Immunodeficiency Virus 09-129 2008 Fire Management Wildfire Indians and Basin Complex Fires FM-2781 2008-02 08-244 2008 Local Emergency Hazmat Emergency Asbestos Remediation 08-234 2007 Major Disaster Freeze Severe Freeze DR-1689 2007-02 2007 Local Emergency Flood Carmel River & Lagoon Flooding 07-309 2006 Local Emergency Hazmat Emergency Asbestos Remediation 06-267 2006 Local Emergency Flood Severe Winter Storms 06-006 2005 Local Emergency Erosion Road Erosion on Scenic Road 05-118 2005 Local Emergency Flood Carmel River & Lagoon Flooding 05-085 2004 Local Emergency Severe Storms Severe Winter Storms 04-058 2003 Local Emergency Public Health Human Immunodeficiency Virus 03-034 1999 Major Disaster Freeze Severe Freeze DR-1267 98-02
1998 Major Disaster Severe Storms El Nino '98 Winter Storms DR-1203 98-01 1997 Major Disaster Severe Storms Severe Winter Storms, DR-1155 97-01 1995 Major Disaster Severe Storms 1995 Late Winter Storms DR-1046 95-03 1995 Major Disaster Severe Storms 1995 Winter Storms DR-1044 95-01 1993 Major Disaster Flood 1993 Winter Storms DR-979 93-01 1991 Major Disaster Freeze Severe Freeze DR-894
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As seen in Figure 4-1, the top three hazards resulting in a declaration of any kind are Flooding (29%), Severe Storms (20%), and Wildfires (16%).
Figure 4-1
Historical Declared Hazard Events in Monterey County by Hazard Type (1990-2021)
Figure 4-1: Historical Declared Hazard Events by Hazard Type (1990- 2021)
4.1.2 EOC ACTIVATIONS
The County maintains a list of Emergency Operations Center (EOC) activations. As seen from the list of EOC Activations, winter storms, wildfires, flooding, and utility outages were the most common hazards requiring activation of the EOC. EOC activations from 2006 to present include:
• 2022 Tsunami • 2021 Car Week • 2021 Winter Storms
• 2021 Willow Fire • 2020 Wildfires • 2020 COVID-19
• 2019 PSPS Event • 2019 Chualar Flood • 2017 Winter Storms • 2017 Pajaro Sewage Spill • 2016 Winter Storms • 2016 Chimney Fire • 2016 Soberanes Fire • 2016 Phone Outage • 2015 Power Outage • 2015 Tassajara Fire • 2014 Winter Storms • 2014 Natividad Water Issue • 2014 Drought • 2014 Debris Flows • 2013 Pfeffer Fire
• 2009 Mudslide • 2009 H1N1 Influenza • 2009 Dayton Hazmat Incident • 2008 Basin Complex Fire • 2006 Soledad MCI • 2008 Winter Storms Debris Flow
4%
Drought
2%
Erosion
4%
Flood
29%
Freeze
5%
Hazardous
Materials
5%
Public
Health
7%
Saltwater
Intrusion
4%
Severe Storms
20% Tsunami
2%
Utility
Interruption
2%
Wildfire
16%
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4.2 HAZARD PROFILES
The hazards identified in Table 4-1 Hazards of Concern, were profiled individually in identified sections. These profiles set the stage for the risk assessment, where exposure and vulnerability are quantified for each of the identified hazards. Each hazard is profiled in the following format:
Hazard Overview: This section gives a description of the hazard and includes definitions and background, scientific, and regulatory information, as applicable.
Hazard History: This section contains information on previous occurrences of the hazard in the County. Historical hazard information is helpful in estimating the likelihood of future events and predicting potential impacts. When data was available, the extent of the impacts, such as fatalities, injuries, building and infrastructure damages, and loss of services, were included.
Location: This section includes information on the geographic location of areas affected by the hazard in Monterey County. Generally, maps were used to illustrate location for many of the hazards. National, state, and County databases were reviewed to locate available spatially based data relevant to this planning effort.
Maps were produced using Geographic Information System (GIS) to show the spatial extent and location of hazards when such datasets were available. These maps are included in the hazard chapters of this plan. When mapping was not available or deemed not the most appropriate way to identify the location, narrative description was used. Some hazards affect the entire County uniformly, in which case specific location or extent was not identified.
Frequency: This section describes the frequency and likelihood of future occurrences of the hazard. The frequency and likelihood of the hazard occurring in the future and can be described in a variety of ways. Where possible, frequency was calculated based on existing data. Hazard likelihood was compared using the following general descriptions:
• Unlikely: Less than 1% chance of occurrence in next 100 years or has a recurrence interval of greater than every 100 years.
• Occasional: Between 1 and 10% chance of occurrence in the next year or has a recurrence interval of 11 to 100 years.
• Likely: Between 10 and 100% chance of occurrence in next year or has a recurrence interval of 10 years or less.
• Highly Likely: Near 100% chance of occurrence in next year or happens every year.
Severity: Severity, or extent, is defined as the strength or magnitude of a hazard. Depending on the hazard, the severity was described in a combination of ways including:
• The value on an established scientific scale or measurement system • Other measures of magnitude, such as water depth or wind speed • The duration of hazard events
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Warning Time: This section describes the warning time and speed of onset for the hazard.
Secondary Hazards: This section seeks to examine the vulnerabilities of hazard events beyond the individual hazard. Often another hazard occurs as a secondary hazard, such as an earthquake causing a landslide or tsunami or a wildfire. Other events are compounded by outside factors, such as wildfire evacuations occurring during Public Safety Power Shutoff (PSPS) events. This section was included to highlight compounding hazard risks by highlighting secondary hazards and local conditions that accelerate impacts.
4.3 RISK ASSESSMENT METHODOLOGY
The Risk Assessment measures the potential impact on life, property, critical infrastructure, the environment, and the economy resulting from the hazards profiled. The intent of the Risk Assessment is to identify the qualitative and quantitative vulnerabilities of the community to the greatest extent possible given available data. The Risk Assessment increases understanding of hazard impacts to the community and provides a foundation to develop and prioritize mitigation actions. In turn, mitigation actions reduce damage from natural disasters through increased preparedness and focus resources to areas of greatest vulnerability.
This section provides an overview of the methods used for the risk assessments for each hazard identified. Vulnerabilities to each hazard were assessed in a two-step process. First, population, critical facilities, county parcels, and structures were inventoried to develop a “lay of the land.” Then, those inventories were utilized in calculating estimated exposure and damage from hazards at various levels of severity.
The Risk Assessment utilized geospatial data along with local knowledge of past events.
Geospatial data was essential in determining population and assets exposed to hazards and was conducted if a natural hazard has a spatial footprint that could be analyzed against the locations of people and assets.
4.3.1 POPULATION AND ASSET INVENTORY
In order to describe the risk posed by each hazard, it was important to first understand the total population and assets at risk. The population and asset inventories provided a baseline to measure the significance of hazard events and vulnerability to those events.
Supervisorial Districts and Political Subdivisions
For the purposes of Countywide analysis, the 2010 Supervisorial Districts were used to conceptualize the geographic distribution of population and property. Figure 4-2 shows the geographic location of each Supervisorial Districts in Monterey County.
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Figure 4-2
2010 Monterey County Supervisorial Districts
Figure 4-2: 2010 Monterey County Supervisorial Districts
Supervisorial Districts in Monterey County include the following geographic areas:
District 1 is geographically the smallest supervisorial district in Monterey County and is entirely within the city limits of the city of Salinas.
District 2 is the northernmost supervisorial district in Monterey County, the 2nd District includes the communities of Boronda, Castroville, Las Lomas, Moss Landing, Pajaro, Prunedale, Royal Oaks, the northern neighborhoods of the city of Salinas, and those portions of the community of Aromas that are located within Monterey County.
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District 3 covers the majority of the Salinas Valley and southern Monterey County, extending to its border with San Luis Obispo County. The district includes the unincorporated communities of Spreckels, Chualar, Jolon, the eastern portion of the city of Salinas, and the cities of Gonzales, Greenfield, Soledad, and King City. Additionally, it includes the military installations at Fort Hunter Liggett and Camp Roberts, as well as portions of the Los Padres National Forest.
District 4 includes the southwest portion of the city of Salinas, the cities of Del Rey Oaks, Marina, Seaside, Sand City, and the former military installation at Fort Ord.
District 5 is geographically the largest of the five districts and covers most of the Monterey Peninsula and southern coastline of the County down to the southern border with San Luis Obispo County. The 5th District includes the cities of Carmel-by-the-Sea, Monterey, and Pacific Grove, the unincorporated communities of Carmel Valley Village, Big Sur, Pebble Beach, San Benancio, Corral de Tierra, and Jamesburg. Additionally, it includes the military installations at the Presidio of Monterey, the Defense Language Institute, and the Naval Postgraduate School, as well as the Ventana Wilderness area of the Los Padres National Forest.
Population
Each natural hazard affects County residents differently depending on the location of the hazard and the population density where the hazard event could occur. Risk assessments presented in this section summarize the population exposure for each natural hazard if available.
To produce the hazard-specific risk assessments, first the population near each hazard was determined. Population estimates were derived from 2010 Census information. Census blocks were used to determine the population exposed to the hazards.
Parcel Value Inventory
Monterey County Assessor’s data was used to develop both residential and non-residential values exposed to hazards. Residential and nonresidential parcels were identified using Assessor's Land Use Codes.
The Parcel Value Inventory includes total assessed value of the land and of any structures on the land. These elements are combined because, in the event of a disaster, the value of the infrastructure or improvements to the land is usually the focus and the land itself is not a total loss. Each hazard profile outlines predicted impacts to this Inventory based on each hazard’s geographic extent.
The Monterey County Parcel and Population Inventory is summarized in Table 4-4.
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Table 4-4: Monterey County Parcel and Population Inventory Table 4-4
Monterey County Parcel and Population Inventory
Jurisdiction Population Residential Non-Residential
Count Value ($) Count Value ($)
Carmel-by-the-Sea 3,460 2,489 $4,071,156,577 888 $691,544,498 Del Rey Oaks 1,000 584 $276,553,256 144 $55,959,358
Gonzales 6,758 1,303 $437,053,854 479 $193,034,179
Greenfield 13,299 2,574 $749,316,532 585 $176,076,227
King City 10,970 1,874 $552,522,904 898 $284,138,790
Marina 18,939 3,603 $2,163,216,447 1,388 $582,115,264
Monterey 26,998 6,533 $4,016,887,152 5,671 $2,661,097,840 Pacific Grove 15,030 4,798 $3,545,159,214 1,763 $441,654,454 Salinas 133,018 23,032 $9,261,979,929 9,025 $3,159,440,145 Sand City 324 157 $32,386,952 644 $320,490,499
Seaside 28,456 5,461 $2,345,735,210 2,159 $481,073,182
Soledad 22,713 2769 $1,049,529,544 703 $147,123,893
Supervisorial District
District 1 74,822 9,872 $3,434,995,377 4,619 $1,674,390,014 District 2 73,812 16,226 $7,225,922,676 8,558 $2,369,919,832 District 3 76,581 12,949 $4,353,858,958 10,695 $5,609,556,661 District 4 71,735 15,072 $7,553,619,336 7,009 $2,506,288,306 District 5 81,657 29,599 $32,363,271,436 14,367 $6,397,430,508
Critical Facilities and Infrastructure
Critical facilities and Infrastructure were of particular concern when conducting the Risk Assessment. A critical facility is a structure or other improvement that, because of its function, size, service area, or uniqueness, has the potential to cause disruption of vital socioeconomic activities if it is destroyed, damaged, or functionally impaired. Critical facility points include police stations, fire stations, hospitals, elder care facilities, day care facilities, buildings containing hazardous materials, schools, transportation infrastructure, utilities, and government buildings. Critical lifelines include communication, electric power, liquid fuel, natural gas, and transportation routes.
A critical infrastructure spatial database was developed to translate critical facilities information into georeferenced points and lines. The critical facilities inventory was developed from a variety of sources, including County, City, State, Federal, and industry datasets.
Table 4-5 lists critical infrastructure data sources. All data sources have a level of accuracy acceptable for planning purposes. Due to the sensitivity of this information, a detailed list of facilities is not provided. The risk assessment for each hazard qualitatively discusses critical facilities with regard to that hazard.
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Table 4-5: Critical Infrastructure and Assets Data Sources Table 4-5
Critical Infrastructure and Assets Data Sources
Critical Facilities and Assets Source
Emergency Operation Centers, Fire Stations, Police
Stations, Schools, Airports, Electric Power Facilities, Landfills, Military Facilities, Large Public Facilities 2015 Monterey County Local Hazard
Mitigation Plan, data reviewed and
updated by County OES, PG&E
Hospitals and Medical Care Facilities Monterey County GIS, PG&E Dams US Army Corps of Engineers National
Inventory of Dams
Harbors Monterey County GIS
Hazardous Material Facilities Monterey County GIS: Underground Tanks, Cal ARP Facility
Transportation Infrastructure- Roads, Highways,
Bridges, and Railroads Monterey County GIS
Communications Facilities Monterey County GIS, PG&E
Water and Wastewater Infrastructure
Monterey County GIS, M1W provided
GIS layer of collection system including
conveyance pipelines and pump
stations
Rain Gauges Monterey Water Resources Agency
Stormwater Infrastructure Monterey County GIS
Oil Wells
California Department of
Conservation, Geologic Energy
Management Division's (CalGEM) Well
Finder (WellSTAR)
4.3.2 HAZARD EXPOSURE
The asset and population inventory information were then used to generate specific exposure and damage estimations based on the severity of specific hazard events. “Exposure” of assets and population refers to the total counts of parcels, people, facilities, and assets within the County in which a hazard event may occur.
A natural hazards overlay was developed to reflect the combination of many known natural hazard spatial footprints. The spatial overlay method enables summarization of building values, parcel counts, population exposure, and critical facility exposure within a hazard’s geographic extents.
In Monterey County, coastal erosion, dam failure, levee failure, hazardous materials incidents, earthquake liquefaction, flooding, slope failure, sea level rise, tsunami, and wildfire have identifiable geographic extents and corresponding spatial information about each hazard.
Table 4-6 summarizes the data sources used for each of these hazards.
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Table 4-6: Hazard Exposure Data
Table 4-6
Hazard Exposure Data
Hazard Data Source Severity and Exposure
Coastal
Erosion
USGS Coastal Storm Modeling System
(CoSMoS), Central California Projections
of Coastal Cliff Retreat and Shoreline
Change due to 21
st Century Sea Level
Rise
To determine exposure, the Hold the Line
Management Scenario was used for both
coastal cliff retreat and shoreline change.
For shoreline change, Continued
Nourishment Management Scenario, in
addition to modeling which forced Sea Level
Rise in 2100 at 200 cm. Based on OPC High
Risk Aversion Guidance, the following sea
level rise levels were chosen: 25 cm Sea
Level Rise (2030, near future risk; 75 cm Sea
Level Rise (2060); and 200 cm Sea Level Rise
(2100).
Dam Failure
• Nacimiento- Monterey County GIS
• San Antonio- Monterey County GIS
• Forest Lake Dam- Pebble Beach
Community Services District
• Los Padres Dam- CA DOSD
Exposure risk was based on the following:
• Nacimiento- Spillway Failure, Dam
Failure
• San Antonio- Spillway Failure, Dam
Failure
• Forest Lake Dam- 4 Failure Scenarios
• Los Padres Dam- Inundation area
Levee Failure Army Corp of Engineers National Levee
Database
Leveed Areas was used to determine
exposure risk.
Hazardous
Materials
Incident
Mobile- US Dept of Transportation,
National Transportation Atlas Database
Fixed-Monterey County Hazardous
Materials Plan (2019)
Based on guidelines in the US Department of
Transportation’s Emergency Response, the
recommended buffer distance or
“protective action distance” of one mile was
used, around mobile and fixed facilities to
determine exposure risk.
Earthquake
Liquefaction Monterey County GIS High and moderate liquefaction potential areas used to determine exposure risk.
Flooding FEMA FIRM (2018) 100-year and 500-year floodplain used to determine exposure risk.
Slope Failure Earthquake Induced Landslide Risk,
Monterey County 2010 General Plan
High and moderate earthquake induced
landslide potential areas used to determine
exposure risk, in addition to data from the
FEMA National Risk Index.
Sea Level
Rise
National Oceanic and Atmospheric
Administration (NOAA), Sea Level Rise
Data
Based on OPC High Risk Aversion Guidance,
the following sea level rise levels were
chosen: 1 ft Sea Level Rise (2030); 3 ft Sea
Level Rise (2060); and 7 ft Sea Level Rise
(2100) to determine exposure.
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Table 4-6
Hazard Exposure Data
Hazard Data Source Severity and Exposure
Tsunami
California Geological Survey, Tsunami
Inundation Maps, Monterey County
Tsunami Hazard Areas (2021)
Tsunami Inundation Zone used to determine
exposure risk.
Wildfire CALFIRE Fire Threat
Statewide GIS layer in raster format of fire
threat, which combines expected fire
frequency with potential fire behavior to
create 4 threat classes. Very High, High, and
Moderate Threat Zones were considered
areas exposed to wildfire risk.
FEMA National Risk Index
The FEMA National Risk Index was also used to enhance the risk assessment. The National Risk Index incorporates physical and social vulnerability data to identify communities more at-risk to the adverse impacts of natural hazards. The National Risk Index is a high quality, comprehensive data set that identifies a community’s risk to natural hazards.
Community risk in the National Risk Index is a combination of several factors, including the expected annual dollar loss related to building value, crop, or population, due to a natural hazard; social vulnerability, which measures how social groups respond to the adverse impacts of natural hazards; and community resilience, which is the community’s ability to recover from a natural disaster.
4.3.3 HAZARD VULNERABILITY
Included in the risk assessment was a consideration of hazard vulnerability. Vulnerability is the characteristics of community assets that make them susceptible to damage from a given hazard. The vulnerability of people, property, critical infrastructure, the environment, and the economy is discussed within each respective risk assessment section for each hazard.
Vulnerability was evaluated by interpreting the probability of occurrence of each event and assessing structures, facilities, and systems that are exposed to each hazard. Additionally, vulnerability was assessed qualitatively using local knowledge.
Environmental Impacts
Monterey County has many important environmental assets and natural resources. These resources are critical to community identity and quality of life and support the economy through agriculture, tourism and recreation, and a variety of other ecosystem services, such as clean air and water. Hazards profiled in this Plan can have impacts on the natural environment and are discussed qualitatively in this section.
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The natural environment also provides protective functions that reduce hazard impacts and increase resiliency. For instance, wetlands and riparian areas help absorb flood waters, soils and landscaping contribute to stormwater management, and vegetation provides erosion control and reduces runoff. Conservation of environmental assets may present opportunities to meet mitigation and other community objectives, such as protecting sensitive habitat, developing parks and trails, or contributing to the economy.
Economic Impacts
After a disaster, economic resiliency drives recovery. Monterey County has a variety of specific economic drivers that are important to understand when planning to reduce the impacts of hazards and disasters to the local economy. Depending on the hazard, economic impacts in this section were described in terms of indirect losses, such as functional downtime and loss of employment wages, and in terms of the impact to primary economic sectors
4.3.4 LIMITATIONS
Loss estimates, exposure assessments, and hazard-specific vulnerability evaluations rely on the best available data and methodologies. Uncertainties are inherent in any loss estimation methodology and arise in part from incomplete scientific knowledge concerning natural hazards and their effects on the built environment. Uncertainties also result from the following:
• Approximations and simplifications necessary to conduct a study • Incomplete or outdated inventory, demographic, or economic parameter data • Missing data on value of structure or land
• Population assessed based on census blocks, which differs from physical residents in a hazard area
• The unique nature, geographic extent, and severity of each hazard • Mitigation measures already employed
• The amount of advance notice residents has to prepare for a specific hazard event • The uncertain spatial accuracy of a variety of the data used to assess hazard exposure • Lack of a standardized model for assessing sea level rise impacts. Multiple models provide multiple results. Not all models were run in the development of the sea level rise analysis.
These factors can affect loss estimates by a factor of two or more. Therefore, potential exposure and loss estimates are approximate and should be used only to understand relative risk. Over the long term, Monterey County will collect additional data to assist in estimating potential losses associated with other hazards.
4.4 HAZARD PRIORITIZATION AND RISK RANKING
FEMA requires all hazard mitigation planning partners to have jurisdiction-specific mitigation actions based on local risk, vulnerability, and community priorities. This plan included a risk COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 4-20 RISK ASSESSMENT
ranking protocol for each planning partner, in which “risk” was calculated by adding the extent of hazard, the likelihood of future occurrence, the severity, and the impact on people, property and the economy.
The risk ranking was used to identify mitigation actions for hazards. The risk ranking at the planning partner scale was used to inform the action plan development process for each partner. Planning partners were directed to identify mitigation actions addressing hazards that, at a minimum, had a “high” risk ranking. Actions that address hazards with a substantial, moderate, possible, slight, negligible hazard ranking are considered optional by this planning process. The following Countywide risk ranking was prepared by the planning team. The results are used in establishing mitigation priorities.
Each participating jurisdiction also completed the hazard prioritization process specifically for the hazards applicable to their jurisdiction, and this important initial stage informed the rest of the planning process for each jurisdiction. Individual hazard prioritization matrices are available in Volume 2 of this MJHMP.
4.4.1 THREAT HAZARD RISK ASSESSMENT SURVEY
The risk ranking process was conducted using the Threat Hazard Risk Assessment Survey. All stakeholders took the Threat Hazard Risk Assessment Survey. The purpose was both the gauge perceived risk and to rank and prioritize the hazards. The survey assisted in the creation of a risk matrix, in order to compare hazards and rank which pose the greatest risk. Based on the survey each identified hazard was given a rank based on geographic extent, likelihood of future occurrences, magnitude, and impacts
The score for each variable by hazard was calculated using a weighted average of all survey responses. Variables were then summed to create results for each Individual jurisdiction (summarized in Volume 2). For the Countywide THIRA overall jurisdiction risk ranking scores by hazard for likelihood, magnitude, and impact were used and weighted by population in the jurisdiction (as a percentage of the total County population).
Municipal jurisdictions scores comprised 75% of the total score per variable, participating special district scores compromised 15% of the total score (weighted by population served), and stakeholder scores (collected as described in Stakeholder Engagement) comprised 10% of the total score. Geographic extent which was weighted by land area (as a percentage of the total County land area). The risk index was helpful tool to compare multiple hazards, but it is not a complete risk assessment and is supplementary to the more detailed risk analysis provided in each hazard chapter.
Variables
Variables were based on the hazard profiles as described above and, on the FEMA, Local Mitigation Planning Handbook. The following variables, questions, and guidance shaped the ranking on the matrices:
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Geographic Extent: What geographic area is affected by this hazard?
1. Negligible: No known or negligible geographic extent
2. Limited: Less than 10% of Planning Area
3. Significant: 10-50% of Planning Area
4. Extensive: 50-100% of Planning Area
Likelihood of Future Occurrences: What is the likelihood of a hazard event occurring in a given year?
1. Unlikely: Less than 1% chance of occurrence in next 100 years or has a recurrence interval of greater than every 100 years.
2. Occasional: Between 1 and 10% chance of occurrence in the next year or has a recurrence interval of 11 to 100 years.
3. Likely: Between 10 and 100% chance of occurrence in next year or has a recurrence interval of 10 years or less.
4. Highly Likely: Near 100% chance of occurrence in next year or happens every year.
Magnitude/ Severity: What is the expected magnitude and severity of the hazard event based on historic events or future probability?
1. Negligible: Less than 10% of property severely damaged, shutdown of facilities and services for less than 24 hours; and/or injuries treatable with first aid
2. Limited:10-25% of property severely damaged; shutdown of facilities for more than a week; and/or injuries treatable do not result in permanent disability
3. Critical: 25-50% of property severely damaged; shutdown of facilities for at least two weeks; and/or injuries and/or illnesses result in permanent disability
4. Catastrophic: More than 50% of property severely damaged; shutdown of facilities for more than 30 days; and/or multiple deaths
Impact: In terms of injuries, damage, or death, would you anticipate impacts to be negligible, limited, critical, or catastrophic when a significant hazard event occurs?
1. Negligible: no meaningful impact
2. Limited: minimal potential impact
3. Critical: moderate potential impact
4. Catastrophic: widespread potential impact
4.4.2 RANKING METHODOLOGY
To determine the rank, each variable was weighted on a scale from 1-4, or negligible/ unlikely to extensive/ highly likely/ catastrophic. The score for each variable by hazard was calculated using a weighted average of all survey responses. Scores on each variable were added together to determine a score between 1 and 16.
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Figure 4-3 demonstrates how individual variable scores were added together to create a total score, associated with a relative degree of risk.
Figure 4-3
Risk Ranking Score Matrix by Variable
Geographic Extent
1 2 3 4
Likelihood
1 4 6 8 10 1
Magnitude/ Severity 2 6 8 10 12 2
3 8 10 12 14 3
4 10 12 14 16 4
1 2 3 4
Impact
Figure 4-3: Risk Ranking Score Matrix by Variable
Each score was associated with a qualitative degree of risk ranking from Negligible (a score between 1 and 4) to Very High (a score between 14.1 and 16). As described below in Table 4-7 Table 4-7: Degree of Risk Scores
Table 4-7
Degree of Risk Scores
Degree of Risk Values
Very High 14.1-16
High 12.1-14
Substantial 10.1-12
Moderate 8.1-10
Possible 6.1-8
Slight 4.1-6
Negligible 1-4
4.4.3 RESULTS
As discussed above, each participating also ranked hazards for its own area. Table 4-8 summarizes the number of times a ranking of very high, high, substantial, moderate, possible, and slight was assigned by a participating jurisdiction based on the numerical ratings that each jurisdiction assigned each hazard. The results indicate the following general patterns:
• The only hazards to receive any very high-risk rankings were drought and water shortage, earthquake, epidemic, pandemic, sea level rise, and severe winter storms. • Drought and water shortage followed by wildfire were the most commonly ranked as high risk. 50% of participating jurisdictions ranked drought as high risk. • Earthquake, followed by utility interruption, and localized stormwater flooding were the most commonly ranked as substantial risk hazards. 67% of participating jurisdictions ranked earthquake as a substantial risk.
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• Flash flood was the most commonly ranked moderate risk hazard, followed by terrorism and then, cyber-attack, hazardous materials incident, and riverine flooding. • Extreme cold and freeze, extreme heat, and mass migration were the most commonly ranked as a possible risk.
• Extreme cold and freeze, mass migration, and slope failure were the most commonly ranked as slight risks. Levee failure was the most commonly unranked hazard.
Table 4-8: Number of Participating Jurisdictions Assigning A Given Ranking to a Hazard Table 4-8
Number of Participating Jurisdiction Assigning a Given Ranking to a Hazard Hazard
Number of Jurisdictions Assigning Ranking to Hazard
Very
High High Substantial Moderate Possible Slight Unranked/ Negligible
Agricultural Emergencies 0 2 5 2 0 3 6
Coastal Erosion 0 3 4 4 0 1 6
Coastal Flooding 0 2 4 2 4 0 6
Cyber-Attack 0 5 4 7 2 0 0
Dam Failure 0 0 1 4 5 2 6
Drought & Water Shortage 1 9 5 0 1 1 1
Earthquake 1 3 12 2 0 0 0
Epidemic 1 4 6 5 1 1 0
Extreme Cold & Freeze 0 0 1 3 7 4 3
Extreme Heat 0 0 2 6 7 0 3
Flash Flood 0 0 3 9 3 1 2
Hazardous Materials Incident 0 1 4 7 5 1 0
Invasive Species 0 0 2 6 3 3 4
Levee Failure 0 0 2 1 3 4 8
Localized Stormwater Flooding 0 0 7 6 4 1 0
Mass Migration 0 0 1 0 7 4 6
Pandemic 1 5 7 1 3 1 0
Riverine Flooding 0 0 3 7 5 2 1
Sea Level Rise 1 4 4 1 1 1 6
Severe Winter Storms 1 2 4 6 3 1 1
Slope Failure 0 0 4 5 4 4 0
Targeted Violence 0 0 3 6 5 2 0
Terrorism 0 1 2 8 3 3 0
Tsunami 0 3 2 4 2 0 0
Utility Interruption/ PSPS 0 3 8 6 1 0 0
Water Contamination 0 2 5 6 3 1 0
Wildfire 0 7 2 3 2 2 0
Windstorms 0 2 6 4 4 1 0
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Specific jurisdictional results are included in Volume 2 of this Plan. Based on the jurisdictional results and the methodology described above, a countywide Threat Hazard Identification Risk Assessment matrix was created. Table 4-9 summarizes the results of the countywide THIRA.
Table 4-9: Countywide Threat Hazard Identification and Risk Assessment Table 4-9
Countywide Threat Hazard Identification Risk Assessment (THIRA) Hazard Geographic
Extent
Likelihood of
Occurrence
Magnitude/
Severity Impact Total
Out of 16
Degree of Risk
Agricultural Emergencies 2.6 2.1 2.2 2.3 9.1 Moderate
Coastal Erosion 2.5 1.9 1.8 1.8 8.0 Moderate
Coastal Flooding 2.6 1.8 1.9 1.9 8.2 Moderate
Cyber-Attack 2.3 2.6 2.7 2.9 10.5 Substantial
Dam Failure 2.7 1.2 1.2 1.8 6.9 Possible
Drought & Water Shortage 3.1 3.0 3.0 3.1 12.3 High
Earthquake 2.9 2.9 3.1 3.1 11.9 Substantial
Epidemic 2.6 2.5 2.8 2.7 10.7 Substantial
Extreme Cold & Freeze 2.0 1.6 1.6 1.6 6.7 Possible
Extreme Heat 2.8 2.0 1.7 1.8 8.2 Moderate
Flash Flood 2.4 1.9 2.0 2.1 8.4 Moderate
Hazardous Materials Incident 1.8 2.4 2.5 2.5 9.2 Moderate Invasive Species 2.5 1.7 1.7 1.7 7.7 Possible
Levee Failure 2.4 1.2 1.0 1.4 6.1 Possible
Localized Stormwater Flooding 2.8 2.6 2.4 2.4 10.2 Substantial Mass Migration 2.0 1.4 1.4 1.4 6.3 Possible
Pandemic 2.9 2.5 2.9 2.9 11.2 Substantial
Riverine Flooding 2.3 2.1 2.1 2.1 8.6 Moderate
Sea Level Rise 2.6 1.9 2.1 2.0 8.6 Moderate
Severe Winter Storms 2.7 2.5 2.5 2.5 10.1 Substantial
Slope Failure 2.5 1.9 2.0 2.0 8.5 Moderate
Targeted Violence 1.8 1.9 2.1 2.2 7.9 Possible
Terrorism 1.8 1.6 2.1 2.1 7.5 Possible
Tsunami 2.1 1.2 1.4 1.4 6.1 Possible
Utility Interruption/ PSPS 2.4 2.7 2.5 2.6 10.2 Substantial Water Contamination 2.6 2.0 2.5 2.5 9.6 Moderate
Wildfire 3.2 2.4 2.6 2.6 10.8 Substantial
Windstorms 2.3 2.4 2.3 2.3 9.3 Moderate
Based on the THIRA results, Table 4-10 shows the hazard ranking for all hazard considered in the plan update.
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Table 4-10: Countywide Hazard Risk Ranking
Table 4-10
Countywide Hazard Risk Ranking
Ranking Hazard Total Degree of Risk
1 Drought & Water Shortage 12.3 High
2 Earthquake 11.9 Substantial
3 Pandemic 11.2 Substantial
4 Wildfire 10.8 Substantial
5 Epidemic 10.7 Substantial
6 Cyber-Attack 10.5 Substantial
7 Utility Interruption/ PSPS 10.2 Substantial
8 Localized Stormwater Flooding 10.2 Substantial
9 Severe Winter Storms 10.1 Substantial
10 Water Contamination 9.6 Moderate
11 Windstorms 9.3 Moderate
12 Hazardous Materials Incident 9.2 Moderate
13 Agricultural Emergencies 9.1 Moderate
14 Riverine Flooding 8.6 Moderate
15 Sea Level Rise 8.6 Moderate
16 Slope Failure 8.5 Moderate
17 Flash Flood 8.4 Moderate
18 Extreme Heat 8.2 Moderate
19 Coastal Flooding 8.2 Moderate
20 Coastal Erosion 8.0 Moderate
21 Targeted Violence 7.9 Possible
22 Invasive Species 7.7 Possible
23 Terrorism 7.5 Possible
24 Dam Failure 6.9 Possible
25 Extreme Cold & Freeze 6.7 Possible
26 Mass Migration 6.3 Possible
27 Tsunami 6.1 Possible
28 Levee Failure 6.1 Possible
COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan
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COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 5-1 AGRICULTURAL EMERGENCIES
5. AGRICULTURAL EMERGENCIES
5.1 OVERVIEW
Agriculture is the backbone of Monterey County’s economy. Agriculture has always been an integral part of the County and has continually grown and changed along with the County. The soils and climate in the region make the County an ideal area to sustain a wide variety of agricultural endeavors. Agriculture in Monterey County is a mosaic of farmland intermingled with other uses in a rural setting. This land provides marketable products, open space, wildlife habitat, watershed benefits, and an aesthetic environment.
For purposes of this plan, an agricultural emergency is any type of unintentional event that threatens human health and the economic stability of the agricultural industry in Monterey County. This primarily includes any event or threat that has the ability to cause widespread losses of crops, livestock, and farm property. Agricultural losses occur on an annual basis and are usually associated with severe weather events, heavy rains, floods, heat, freeze, drought, fires, crop and livestock disease, insects, and noxious weeds.
5.1.1 NATURAL DISASTERS & SEVERE WEATHER
According to the US Department of Agriculture (USDA), every year natural disasters, such as droughts, earthquakes, extreme heat and cold, floods, fires, earthquakes, hail, landslides, and tornadoes, challenge agricultural production. Because agriculture relies on the weather, climate, and water availability to thrive, it is easily impacted by natural events and disasters.
Agricultural impacts from natural events and disasters most commonly include contamination of water bodies, loss of harvest or livestock, increased susceptibility to disease, and destruction
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of irrigation systems and other agricultural infrastructure. These impacts can have long lasting effects on agricultural production including crops, forest growth, and arable lands, which require time to mature. These types of events may also include accidental threats related to the release of hazardous materials and/or explosive hazards, which can not only cause agricultural losses but also directly affect human health.
More in-depth risk assessments for Drought (Section 8), Flooding (Section 10), Hazardous (Section 11), Severe Weather(Section 14), and Wildfire(Section 18) are included in this plan. As they all pose a potential agricultural hazard they are discussed briefly in this section.
5.1.2 PESTS, WEEDS, AND DISEASES
Pest and diseases are a critical threat due to their potential to cause economic and human health disasters. The Monterey County Office of the Agricultural Commissioner has active programs in place to monitor, detect, quarantine, eradicate, and manage pest and disease threats to Monterey County’s agricultural sector.
Insect pest hazards can have a major economic impact on farmers, farm workers, packers, and shippers of agricultural products. They can also cause significant increases in food prices for consumers due to shortages. The primary pests of concern include:
• Mediterranean Fruit Fly • Melon Fruit Fly
• Glassy-Winged Sharpshooter • Japanese Beetle
• Gypsy Moth • Mexican Fruit Fly
• Asian Citrus Psyllid • Light Brown Apple Moth
• Oriental Fruit Fly • European Grapevine Moth
These pests have a wide host range and are difficult and costly to manage once established.
Noxious weeds, defined as any plant that is liable to be troublesome, aggressive, intrusive, detrimental, or destructive to agriculture, silviculture, or important native species, and difficult to control or eradicate, are also of concern. Weeds of concern in Monterey County include:
• Fertile Capeweed • Yellowstar-thistle
• French Broom • Veldt Grass
• Cape Ivy • Taurian Thistle
• Arundo • Puna Grass
• Pampas Grass • Skeletonweed
• Purple Pampas Grass • Scotch Thistle
• Sticky Eupatorium
The rich soils and moderate climate of Monterey County make it an ideal place for invasive weed species to colonize. Invasive weeds are generally able to out-compete local native plant species for water and space because they are more prolific, have more vigorous growth, and COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 5-3 AGRICULTURAL EMERGENCIES
lack predators that would otherwise help to keep them in check. They degrade habitat for other wildlife, domestic animals, recreation, and other land use activities. The agricultural industry is particularly affected by weeds.
Noxious weeds have been introduced in Monterey County by a variety of means. An absence of natural controls, combined with the aggressive growth characteristics and unpalatability of many of these weeds, allows these weeds to dominate and replace more desirable native vegetation. Negative effects of weeds include the following:
• Loss of wildlife habitat and reduced wildlife numbers • Loss of native plant species
• Reduced livestock grazing capacity
• Increased soil erosion and topsoil loss
• Diminished water quality and fish habitat
• Reduced cropland and farmland production
• Reduced land value and sale potential
The consequences of agricultural disasters to the County include ruined plant crops, dead livestock, ruined feed and agricultural equipment, monetary loss, job loss, and possible multi- year effects (i.e., trees might not produce if damaged, loss of markets, food shortages, increased prices, possible spread of disease to people, and loss or contamination of animal products). When these hazards cause a mass die-off of livestock, other issues occur that include the disposal of animals, depopulation of affected herds, decontamination, and resource problems. In addition, insect pests and diseases such as bark beetles, Sudden Oak Death, and Pitch Canker in trees can destroy large expanses of forest and woodland, increasing the fuel load and contributing to greater fire risk. Overall, any type of severe agricultural disaster can have significant economic impacts on both the agricultural community and the entire County.
5.2 HAZARD PROFILE
5.2.1 HISTORY
Monterey County has experienced numerous agricultural-related disasters of varying magnitudes. The County received Presidential Major Disaster Declarations for severe freezing and crop damages in 2007, 1999, and 1991, and for a severe drought emergency in 1977. Major agricultural losses have also occurred following many of the other presidentially declared major disasters for Monterey County. For instance, it is estimated that the 1995 flood disaster resulted in $240 million in losses to crop production in the Salinas Valley.
Over the past 10 years, the US Department of Agriculture has declared 27 agricultural disasters in Monterey County, which are listed in Table 5-1. USDA Disaster Declarations make emergency loan assistance available to eligible family farmers to cover physical and production losses.
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Table 5-1:USDA Agricultural Disaster Designations in Monterey County (2012 -2021) The most common cause of these disasters over the past several years have been, in order of frequency: drought, high winds, excessive heat, wildland fire, insects, excessive rain, and freezing temperatures. There has been an estimated $15.3 million in crop damages for Monterey County since 1996. Approximately $7 million is associated with severe freezing temperatures in 2007, about $7 million was attributed to wildfire events, and nearly $2 million to flood events.
Table 5-1
USDA Agricultural Disaster Designations in Monterey County (2012-2021) Designation
Number Disaster Type Crop Disaster
Year
S4916 Drought 2021
S4467 Drought 2019
S4656 Excessive Rain 2019
S4657 Excessive Rain and Hail 2019
S4350 Freeze 2018
S4460 Drought 2018
S4144 Drought 2017
S4163 Drought 2017
S3952 Drought, High Winds, Wildfire, Excessive Heat, and Insects 2016 S4003 Rain and Wind 2016
S4164 Severe Weather, Excessive Rainfall and High Winds 2016 S3784 Drought, High Winds, Wildfire, Excessive Heat, and Insects 2015 S3943 Drought 2015
S3626 Drought, High Winds, Wildfire, Excessive Heat, and Insects 2014 S3637 Drought, High Winds, Wildfire, Excessive Heat, and Insects 2014 S3626 Drought, High Winds, Wildfire, Excessive Heat, and Insects 2014 S3637 Drought, High Winds, Wildfire, Excessive Heat, and Insects 2014 S3743 Drought 2014
S3491 Drought, High Winds, Wildfire, Excessive Heat, and Insects 2013 S3497 Drought, High Winds, Wildfire, Excessive Heat, and Insects 2013 S3504 Drought, High Winds, Wildfire, Excessive Heat, and Insects 2013 S3547 Drought, High Winds, Wildfire, Excessive Heat, and Insects 2013 S3569 Drought, High Winds, Wildfire, Excessive Heat, and Insects 2013 S3268 Drought, High Winds, Wildfire, Excessive Heat, and Insects 2012 S3320 Hailstorm, Rain, and Cold Temperatures 2012
S3379 Drought 2012
S3452 Drought 2012
Source: United States Department of Agriculture (USDA), Disaster Designation Information COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 5-5 AGRICULTURAL EMERGENCIES
The impact of the COVID-19 pandemic on
California agricultural businesses was severe,
unprecedented, and will continue to affect the
industry for the coming years. Impacts occurred
across four main sectors: consumer demand
(retail, export, and food service), agricultural
supply chain (transportation, packing, storage),
producers (crops, dairy, nursery, and meat), and
input suppliers (workers, crop protection,
materials).
The Monterey County Agricultural Commissioner’s
Office conducted a survey of agricultural
producers, which indicated significant losses
particularly among growers providing fresh
produce to the foodservice sector. The closing of
schools and the cancellation of most conferences
and travel resulted in the cancellation of contracts
for fresh produce. Approximately 20% of County
growers responded to the survey and of those
responding to the survey, 38% reported losses. A
total of 2,093 acres were reported as a loss or not
planted.
12 Additionally, Agriculture work sites,
shared worker housing, congested housing, and
shared worker transportation vehicles presented
unique challenges for preventing the spread of
COVID-19.
The wildfires of 2020 presented yet another set of
emergencies for Monterey County agriculture. The
wildfire smoke created a hazard for farmworkers.
Prior to the wildfires, the Agricultural
Commissioner’s Office had started distributing N95
respirators to pesticide applicators. When the first
wildfire struck, the N95 respirators were
redirected to protect farmworkers from the
wildfire smoke. The losses from the 2020 wildfires
occurred primarily to wine grapes and strawberries
and were estimated at $74,586,292.
1 12 Monterey County Ag Community Shows Resilience, Henry S. Gonzales, Monterey County Agricultural Commissioner, April 24, 2021
Mitigation Success Story
Mitigating the Impact of the COVID-19
Pandemic to Farmworkers
Staff from the Agricultural Commissioner’s
Office worked to distribute surgical masks
face coverings, and other protective
equipment directly to farmworkers and
through community-based organizations,
growers, and farm labor contractors. The
Ag Commissioner’s Office distributed
thousands of COVID-19 informational cards
to farmworkers. The Spanish language
wallet-sized cards listed symptoms of
COVID-19, along with information about
where farmworkers could receive free
medical attention, food, and childcare. They
also partnered with several community
groups to create a public service
announcement in Spanish and Mixtec,
speaking directly to farmworkers about the
actions they could take to protect
themselves, their families, and the
community from COVID-19. Isolation
housing was provided to those farmworkers
either diagnosed or exposed to COVID-19
through a unique grower-led program
which ultimately became the model for the
state’s program implemented much later in
the pandemic, called Housing for Harvest.
COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 5-6 AGRICULTURAL EMERGENCIES
5.2.1 LOCATION
Agricultural hazards occur throughout the County where lands are used for farming and grazing.
The County has large swaths of agricultural lands. According to the California Department of Conservation’s Farmland Mapping and Monitoring Program (FMPP), the County has about 165,000 acres of prime farmland, 44,500 acres of farmland of statewide importance, 26,500 acres of unique farmland, and over 1 million acres of grazing land. The map below shows the locations of valuable farmland in the County.
Figure 5-1
Important Farmland in Monterey County
Figure 5-1: Important Farmland in Monterey County
While most agricultural land is located in the unincorporated County and cities may not be directly affected, they are indirectly affected economically when agricultural losses occur.
5.2.2 FREQUENCY
Agriculture in the County is at risk to many hazards: insects, weeds, wildfire, severe weather, as well as downturns in commodity prices. Each of these has a different likelihood, duration, and speed of onset. Some, such as freeze, can have a short onset and a short duration. Drought can have a long onset and long duration. Insects and weeds can have short or long onset, and short or long durations.
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All agricultural losses can have a significant impact on affected communities. As long as severe weather events, insects, and weeds continue to be an ongoing concern, the potential for annual agricultural losses remains.
5.2.3 SEVERITY
The potential severity of agricultural emergencies in Monterey County can perhaps best be quantified by the exposure of production value. Crop values vary from year to year based on production, market, and weather conditions, but according to the Economic Contributions of Monterey County Agriculture Report the economic contribution of Monterey County agriculture is about $11.7 billion annually. This consists of $7.4 billion in combined, direct output from production and processing, plus $4.3 billion in multiplier effects. Nearly one out of every five jobs in the County are related to agriculture which supports 57,503 jobs directly and an additional 6,417 jobs indirectly. 13
Crops grown in Monterey County supply large percentages of total national pounds produced each year: 61% of leaf lettuce, 57% of celery, 56% of head lettuce, 48% of broccoli, 38% of spinach, 30% of cauliflower, 28% of strawberries, and 3.6% of wine grapes. 14 Therefore, a significant agricultural hazard has the potential to severely affect the economy of the entire County and could have widespread effects on food availability in the rest of the Country.
5.2.4 WARNING TIME
Identifying the presence of insects and pests in agricultural lands is the most important step in warning for an agriculture disaster. Once identified, preventing the insects and pests from establishing a population is critical. Communication between farmers to warn each other of the presence of invasive pests and insects so that appropriate measures can be taken to prevent them from establishing a population and negatively impacting crops.
5.3 SECONDARY HAZARDS
The most significant secondary hazard associated with an agriculture disaster is wildfire. Severe infestation of pests and disease in agricultural lands can cause crops to die, creating increased fuel for wildfire. Agricultural lands are open areas with a mix of grasses, shrubs, trees, and crops that, if dried out or dead, could easily ignite and either start or contribute to a wildfire.
Additionally, Ample scientific evidence shows that crops, orchards, grasslands, and other agricultural areas can help protect people and property from wildfires. Agricultural belts around urban areas are especially helpful, where they reduce the fuel load, disrupt advancing fires, and facilitate firefighting efforts. For more information on wildfire risk in Monterey County, refer to Section 18, Wildfire.
13 Monterey County Agricultural Commissioner, 2020, Economic Contributions of Monterey County Agriculture 14 Monterey County Farm Bureau
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5.4 RISK ASSESSMENT
5.4.1 POPULATION
Agricultural disasters pose a serious threat to the local economy and populations directly employed by the agriculture industry. An agricultural disaster has the potential to greatly impact the Monterey County economy, people employed in the agriculture industry, and their families. As noted previously, nearly one out of every five jobs in the County are related to agriculture which supports 57,503 jobs directly and an additional 6,417 jobs indirectly, 15 therefore agricultural emergencies can have a deep impact on the population of Monterey County if it leads to a reduction in jobs.
An agriculture disaster can also pose a threat to human health. Mosquitos carry harmful disease and can transmit diseases to the population. The Africanized honeybee also presents a threat to the population, not because of their sting but because of their aggressive response to a disturbance. The Africanized honeybee will swarm and attach for long periods in the event of a disturbance to their nests.
5.4.2 PROPERTY
All agricultural crops are threatened by and exposed to severe weather events, heavy rains, floods, heat, freeze, drought, fires, crop and livestock disease, insects, and noxious weeds.
Table 5-2 summarizes gross production value of key crop types in Monterey County in 2020 and 2019 as a proxy for crop value threatened by hazards in the County.
Table 5-2: Gross Production Value of Crops in Monterey County Table 5-2
Gross Production Value of Crops in Monterey County
Category 2020 2019
Vegetable Crops $2,524,608,000 $3,099,088,000
Fruits & Nuts $1,124,737,000 $1,028,146,000
Livestock & Poultry $110,891,000 $110,580,000
Nursery Crops $119,836,000 $143,979,000
Field Crops $25,481,000 $24,554,000
Seed Crops & Apiary $4,582,000 $3,645,000
Total $3,910,135,000 $4,409,992,000
Source: Monterey County Agricultural Commissioner
Table 5-2 also demonstrates the impact of the COVID-19 pandemic and 2020 wildfires on crop production. Major increases and decreases in crop production for 2020 include:
15 Monterey County Agricultural Commissioner, 2020, Economic Contributions of Monterey County Agriculture COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 5-9 AGRICULTURAL EMERGENCIES
• Vegetable Crops saw a decrease in value of $574,480,000 to $2,524,608,000. • Fruit and Nut Crops saw an increase of $96,591,000 to $1,124,737,000. (The Fruits and Nuts category without including Wine Grapes values, saw an increase of $176,696,000 or nearly 21%, to $1,018,746,000 due in part to the increase in value of strawberries.) • Wine Grapes saw a significant decrease of 43% or $80,105,000 to reach a total for red and white varietals of $105,991,000 partly due to effects of wildfires, the COVID-19 pandemic, a decrease in production and average price per ton. • Nursery Crops suffered a decrease of 16.8% or $24,143,000 due to reduced acreage, production, and prices once again favoring an increase in imports and demand for cannabis greenhouse production
All agricultural land is threatened by and exposed to severe weather events, heavy rains, floods, heat, freeze, drought, fires, crop and livestock disease, insects, and noxious weeds.
Table 5-3 summarizes the number of acres and value of important agricultural land by type.
Table 5-3: Value of Agricultural Land in Monterey County Table 5-3
Value of Agricultural Land in Monterey County
Supervisorial
District
Prime Farmland Farmland of Statewide Importance
Acres Value Acres Value
District 1 491 $70,953,097 5 $1,768,087
District 2 19,181 $804,422,513 8,741 $635,499,149
District 3 127,881 $3,516,483,171 33,727 $1,876,893,765 District 4 13,635 $381,699,801 1,382 $189,266,984
District 5 4,297 $230,007,594 649 $86,547,025
Total 165,485 $5,003,566,176 44,505 $2,789,975,010
Supervisorial
District
Unique Farmland Grazing Land
Acres Value Acres Value
District 1 24 $51,485,685 0 $0
District 2 8,163 $714,501,131 21,829 $463,542,869
District 3 16,995 $2,212,880,829 937,186 $3,319,092,070 District 4 244 $170,856,593 8,417 $169,830,424
District 5 927 $162,943,833 96,117 $2,630,183,802
Total 26,353 $3,312,668,071 1,063,549 $6,582,649,165
Agricultural land value exposed to wildfire and flood risk was assessed for this plan. Agricultural land exposed wildfire risk was assessed using CAL FIRE Fire Hazard Severity Zones.
Table 5-4 summarizes acres and values of Prime Farmland in Fire Hazard Severity Zones.
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Table 5-4: Prime Farmland Exposed to Wildfire Risk by Fire Hazard Severity Zone Table 5-4
Prime Farmland Exposed to Wildfire Risk by Fire Hazard Severity Zone Supervisorial
District
Very High High Moderate
Acres Value Acres Value Acres Value
District 1 0 $0 0 $0 0 $0
District 2 14 $12,577,575 191 $43,685,766 481 $66,884,478 District 3 315 $91,087,807 3455 $337,096,616 15,763 $903,926,268 District 4 2 $1,120,394 0 $0 0 $0
District 5 43 $47,386,924 250 $35,805,582 741 $33,058,223 Total 375 $152,172,700 3,896 $416,587,964 16,985 $1,003,868,969
Table 5-5 summarizes acres and values of Farmland of Statewide Importance in Fire Hazard Severity Zones.
Table 5-5: Farmland of Statewide Importance Exposed to Wildfire Risk Table 5-5
Farmland of Statewide Importance Exposed to Wildfire Risk by Fire Hazard Severity Zone Supervisorial
District
Very High High Moderate
Acres Value Acres Value Acres Value
District 1 0 $0 0 $0 0 $0
District 2 16 $2,781,112 459 $70,633,137 304 $79,151,933 District 3 3 $9,242,779 1,285 $234,072,137 9,340 $384,329,143 District 4 0 $1,210,897 0 $0 0 $0
District 5 17 $25,691,776 218 $6,278,334 8 $6,278,334 Total 37 $38,926,564 1,963 $310,983,608 9,652 $469,759,410
Table 5-6 summarizes acres and values of Unique Farmland in Fire Hazard Severity Zones.
Table 5-6: Unique Farmland Exposed to Wildfire Risk by Fire Hazard Severity Zone Table 5-6
Unique Farmland Exposed to Wildfire Risk by Fire Hazard Severity Zone Supervisorial
District
Very High High Moderate
Acres Value Acres Value Acres Value
District 1 0 $0 0 $0 0 $0
District 2 53 $13,722,249 1,267 $152,429,770 787 $83,181,508 District 3 203 $89,991,097 3,571 $432,711,859 6,003 $617,457,668 District 4 2 $2,511,838 0 $0 0 $0
District 5 100 $26,134,030 174 $58,265,936 444 $27,945,919 Total 358 $132,359,214 5,012 $643,407,565 7,234 $728,585,095
Table 5-7 summarizes acres and values of Grazing Land in Fire Hazard Severity Zones.
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Table 5-7: Grazing Land Exposed to Wildfire Risk by Fire Hazard Severity Zone Table 5-7
Grazing Land Exposed to Wildfire Risk by Fire Hazard Severity Zone Supervisorial
District
Very High High Moderate
Acres Value Acres Value Acres Value
District 1 0 $0 0 $0 0 $0
District 2 9,760 $51,763,441 7,053 $146,479,709 2,488 $69,632,969 District 3 103,883 $354,760,669 547,587 $1,444,195,814 131,137 $1,258,200,102 District 4 182 $5,416,285 0 $0 0 $0
District 5 35,477 $1,777,052,329 57,070 $1,172,818,716 2,652 $50,503,125 Total 149,301 $2,188,992,724 611,710 $2,763,494,239 136,277 $1,378,336,196
Agricultural land exposed flood risk was assessed using the FEMA 100-year floodplain. Table 5-8 summarizes acres and values of Prime Farmland in the 100-year floodplain.
Table 5-8: Prime Farmland Exposed to Flood Hazard Risk
Table 5-8
Prime Farmland Exposed to Flood Hazard Risk
Supervisorial
District
100-Year Floodplain
Acres Value
District 1 421 $9,816,487
District 2 7,102 $408,922,260
District 3 20,507 $1,317,258,937
District 4 7,121 $269,820,865
District 5 2,290 $104,670,375
Total 37,441 $2,110,488,924
Table 5-9 summarizes acres and values of Farmland of Statewide Importance in the 100-year floodplain.
Table 5-9: Farmland of Statewide Importance Exposed to Flood Hazard Risk Table 5-9
Farmland of Statewide Importance Exposed to Flood Hazard Risk Supervisorial
District
100-Year Floodplain
Acres Value
District 1 0 $0
District 2 320 $158,964,554
District 3 28,707 $811,603,587
District 4 2,457 $141,858,306
District 5 669 $49,773,190
Total 32,152 $1,162,199,637
Table 5-10 summarizes acres and values of Unique Farmland in the 100-year floodplain.
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Table 5-10: Unique Farmland Exposed to Flood Hazard Risk Table-10
Unique Farmland Exposed to Flood Hazard Risk
Supervisorial
District
100-Year Floodplain
Acres Value
District 1 4 $6,466,951
District 2 1,514 $294,890,372
District 3 2,467 $729,573,350
District 4 181 $106,480,197
District 5 195 $62,998,558
Total 4,362 $1,200,409,428
Table 5-11 summarizes acres and values of Grazing Land in the 100-year floodplain.
Table 5-11: Grazing Land Exposed to Flood Hazard Risk
Table 5-11
Grazing Land Exposed to Flood Hazard Risk
Supervisorial
District
100-Year Floodplain
Acres Value
District 1 0 $0
District 2 1,126 $161,714,843
District 3 39,624 $1,145,728,172
District 4 229 $40,332,494
District 5 1,215 $190,067,361
Total 42,193 $1,537,842,870
5.4.3 CRITICAL FACILITIES AND INFRASTRUCTURE
Critical facilities, as defined in this plan, will not be affected by an agriculture disaster.
5.4.4 ENVIRONMENT
Agricultural lands in Monterey County provide a wide variety of ecosystem services that could be threatened by an agricultural hazard including:
• Wildlife Habitat: Providing food, water, shelter, and space to support resident and transient wildlife, especially through riparian areas and perennial vegetation. • Soil Structure, Formation and Fertility: Sustaining healthy soils, the foundation of all life, by managing them in ways that not only support plant growth, but also reduce erosion, prevent landslides, suppress pathogens, sequester carbon, and purify water. • Water Cycling: Maintaining or improving soil moisture and water storage, while minimizing runoff, through cover crops, tillage, residue management, and dozens of related practices.
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• Pest Control: Controlling pests and weeds through many management practices that support their natural enemies, such as raptors, beneficial insects, and other wildlife. • Pollination Services: Supporting agricultural production and healthy ecosystems by providing nesting habitat and floral resources for wild pollinators. • Nutrient Cycling: Managing plant nutrients and soil in ways that help store, transform, and cycle important nutrients in the soil, such as carbon, nitrogen, and phosphorus. • Biodiversity Conservation: Promoting ecosystem productivity, beauty, pest control, and other benefits by managing on-farm streams, trees, shrubs, wetlands, and cropped areas in ways that support diverse plants and animals.
• Atmospheric Gas & Climate Regulation: Reducing greenhouse gas levels through practices that make farm operations more energy efficient, and by building capacity to store carbon.
• Water Quality: Improving and protecting water quality through vegetative buffers, stream bank protection, prescribed grazing, grassed waterways, and other management practices.
• Wildfire Protection: Crops, orchards, grasslands, and other agricultural areas can help protect people and property from wildfires.
While calculating the true value of ecosystem services is quite difficult, there are some methods to try to capture this value. The 2020 Economic Contributions of Monterey County Agriculture Report estimated the value of ecosystem services provided by agricultural lands ranges from $4.7 billion to $10.9 billion, with rangelands delivering the highest value.
5.4.5 ECONOMIC IMPACT
As noted above, agriculture is an important pillar of the Monterey County economy with an economic contribution of about $11.7 billion annually. The agricultural industry also contributions significantly to local tax revenue. Including production and local processing, and after subtracting significant subsidies, estimate indicate agriculture’s net tax contribution in the County in 2018 at $61.9 million to $122.7 million. This included excise, sales, and property taxes, as well as fees, licenses, and permits (but not income taxes). 16 Therefore, the potential
economic impact associated with agricultural hazards is quite high.
Any of the hazards discussed in this chapter can deal a damaging blow to the agricultural industry. When combined, they can undermine not just an individual operation, but the entire industry. One way to reduce the economic risk to the agricultural industry is emphasize product diversification. To assess crop diversification in the County, the Monterey County Agricultural Commissioner used the Shannon-Weaver Index. Created in 1949 for military code breaking, the Shannon Weaver index is widely used by economists, ecologists, and others interested in quantifying diversity.
16 Monterey County Agricultural Commissioner, 2020, Economic Contributions of Monterey County Agriculture COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 5-14 AGRICULTURAL EMERGENCIES
Over the past decade, Monterey County has consistently produced thirty-five major commodities. The relative contribution of individual commodities varied during the period analyzed from 0.25% of the county’s total farm gate value (the minimum threshold in the analysis) to 35.4% of the county total. At first glance, Monterey County’s resulting index of 0.61 seems near the middle of the 0.00 to 1.00 range. But the Shannon-Weaver formula includes a logarithmic function, which complicates interpretation. The 0.61 index is quite high compared to the twenty other California counties analyzed in the study. The index likely suggests exceptional protection from economic shocks. Validating the extent of this protection would require more detailed analysis, but these preliminary results indicate that Monterey County agricultural production is both diverse and well distributed across types.5
5.5 FUTURE TRENDS IN DEVELOPMENT
Possible future strategies to address influences on insect pests and diseases might include:
• Inventory and monitor invasive species that threaten crops • Downscale climate change data to allow informed decisions on biodiversity planning by farmers and rural communities
• Strengthen the dissemination of knowledge, appropriate technologies, and tools to improve management practices related to agricultural biodiversity and ecosystem services
5.6 ISSUES
Key issues related to agricultural emergencies in Monterey County include:
• Large amounts of agricultural land in the Salinas Valley are below sea level and could become at risk due to future sea level rise.
• In Monterey County, water supply is extremely limited during non-drought years. As such, droughts are a serious threat in the County and could have devastating impacts on the agricultural industry, a major economic driver and job provider. • The agricultural industry is a major driver of the local economy and any major impacts to it, could have a major effect on the community.
• Much of the agricultural water supply in Monterey County is susceptible to seawater intrusion.
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6. COASTAL EROSION
6.1 OVERVIEW
Coastal erosion refers to the natural geological process resulting in loss of sand, sediment, vegetation, or soil on beaches, dunes, bluffs, or cliffs along the coast. It is a natural process, caused by waves, winds, tides, storms, and the movement of tectonic plates, but its effects can be exacerbated by human activity. Coastal erosion takes place both gradually over decades, caused by multiyear impacts and long-term climatic change such as sea level rise, lack of sediment supply, subsidence, or long-term human factors such as the construction of shore protection structures and dams, and rapidly, as with landslides or severe storms. Coastal erosion processes are complex and depend on a number of factors such as geologic formation, groundwater seepage, and exposure to wave energy. The Monterey County coastline is variable in terms of geologic composition and exposure to high tides, wave energy and related erosion.
Sections of the coast exhibit a variety of backshore landforms including wide sand and cobble beaches backed by cliffs, sandy beaches backed by sand dunes, secluded and undeveloped pocket beaches, rocky intertidal areas, rocky bluffs, loosely consolidated bluffs, and large sea cliffs. Due to these various backshore types along the shoreline, erosion characteristics also vary significantly.
Chronic Versus Episodic Erosion
Coastal erosion is measured as the rate of change in the position or horizontal displacement of a shoreline over a period of time. Coastal erosion is classified as either episodic or chronic.
Episodic erosion consists of the shore and backshore adjustment that results from short duration, high intensity meteorological and oceanic storm events. This type of event response
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results in shore adjustment and happens during a single storm or during a series of closely spaced storm events within a storm season. Chronic erosion is associated with slow, gradual shoreline adjustment associated with sea-level rise, land subsidence, changes in sediment supply which result from watershed modifications or dam building, and decadal adjustments in rainfall and runoff associated with climate change.
Human alteration of the shoreline can influence long and short-term erosion rates. One of the major causes of beach erosion is the construction of dams and other structures along creeks and rivers that trap sediment and prevent it from reaching the ocean. This deprives the shoreline of the material that would replenish beach sand supplies. Coastal structures such as groins, jetties, seawalls, and breakwaters can also cause increased erosion. Shoreline structures eliminate the natural wave run-up and sand deposition processes and can increase reflected wave action and currents at the waterline. The increased wave action can cause localized scour both in front of and behind structures and prevent the settlement of suspended sediment. This can result in a rapid loss of beach sand in down-current beaches. Seawalls are often used to protect sea cliffs from eroding wave action. These structures, however, can reflect wave energy to strip protective beach sand at an accelerated rate. This may ultimately result in increased sea cliff erosion rates, particularly at sections of coastline adjacent to the seawall.
6.1.1 SAND MINING IN MONTEREY COUNTY
On average, the coastline of southern Monterey Bay is the most erosive shore in California due to a long history of sand mining.
17 Southern Monterey Bay has a long history of sand mining operations and from 1906 to 1990, was the most intensively mined shoreline in the US. 18 As many as six sand mines, which includes the current CEMEX Lapis Plant, were active at various times over the past century in the City of Marina and City of Sand City. The CEMEX Lapis sand mine located in Marina, was the last coastal sand mine in the US, until its closure at the end of 2020. The plant produced an estimated 200,000 to 300,000 cubic yards of sand a year, enough to fill up to 30,000 dump trucks. The sand mine operated for years without permits from the state, claiming that its operations pre-date state laws such as the 1976 Coastal Act. The mine officially stopped operations on Dec. 31, 2020.
6.1.2 TYPES OF COASTAL EROSION
Beach and Dune Erosion
Beach and dune erosion occur through high wave run-up during high tides and increased wave energy that carry sand away from the shoreline. Beach and dune erosion may occur gradually over time as beaches naturally accrete and erode, resulting in mild changes in the shoreline and volume of sand present on the beach. Energetic coastal storms and particularly strong El Niño
17 USGS, 2006, National Assessment of Shoreline Change, Part 3. 18 Sand mining impacts on long-term dune erosion in southern Monterey Bay COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 6-3 COASTAL EROSION
events potentially result in the abrupt loss of large quantities of sediment and increased landward retreat of the shoreline.
Cliffs and Bluff Erosion
Bluff and cliff recession is the most visible aspect of coastal erosion because of the dramatic change it causes to the landscape. As a result, this aspect of coastal erosion usually receives the most attention. Coastal bluff erosion occurs in the form of irreversible landward retreat of coastal bluffs and cliffs. Historical bluff erosion has been episodic in nature with rates that vary throughout Monterey County due to the composition of coastline bluff rock formations and vulnerability to wave interaction with the cliffs.
Rising tides, currents, and waves directed at the base of the bluff cause the erosion of relatively non-resistant rock. As a bluff erodes, the top edge moves landward. This is a natural process that becomes a hazard as it threatens structures or other developed property, infrastructure, as well as recreational trails and public coastal access. The retreat of the bluffs threatens waterfront residences, businesses, and public facilities, eventually rendering them uninhabitable or unusable.
6.2 HAZARD PROFILE
6.2.1 HISTORY
Coastal erosion within Monterey County has primarily occurred during periods of intense wave action coinciding with high tides and coastal storms. El Niño events have produced large waves that have stripped volumes of sand from Monterey Bay, leaving the beaches, dunes, and cliffs exposed to high tides and wave attack.
As a result of the 1982–1983 El Niño events, approximately 20 to 40 feet of the marine terraces by Scenic Drive in Carmel fell into the sea. The 1997–1998 El Niño winter storm event, led to large amounts of dune erosion in the vicinity of Fort Ord (43-foot retreat) and the city of Marina (50-foot retreat). During both El Niño events, several extremely steep cliffs (100% slope) near Big Sur failed because of increased wave attack.
The 2017 Winter Storms resulted in a significant erosion in the Big Sur area, ultimately resulting in major infrastructure failures in Palo Colorado, Mud Creek, Paul’s Slide, and Pfeiffer Canyon Bridge. Coastal erosion coupled with extreme wave action during the 2016-17 El Nino led to the exposure of M1W's land/ocean outfall junction structure. Earthquakes have also caused the Monterey cliffs to erode. The October 17, 1989, Loma Prieta Earthquake produced several isolated cliff failures throughout the County.
Some areas have seen particularly dramatic shoreline retreat. For example, At Fort Ord, a football field existed on the dune between Stillwell Hall and the ocean in 1944. After the field eroded into the ocean, rock rubble was placed in front of Stillwell Hall in 1978 and again in 1985 to stop erosion, but even after sand mining ceased, extreme recession continued to occur at COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 6-4 COASTAL EROSION
the flanks of the rubble. Up to 46 feet of recession occurred during the 1997–98 El Niño winter just to the north of Stillwell Hall. Close to 380 feet of retreat occurred over a 70-year period.
The area still experiences erosion close to 6 feet per year. 19 Historic Erosion Rates
Historic average beach and dune erosion in Southern Monterey Bay (from Moss Landing to Pacific Grove) is approximately 2.6 feet a year and higher than any other region in the state.
Historically, the highest dune erosion rates have occurred in the Fort Ord area (7 feet annually) and Marina (4.5 feet annually) because of wave refraction patterns that produce larger waves.
Long-term historic erosion rates in this area have been variable.
Historic average erosion rates for Southern Monterey Bay are summarized in Table 6-1.
Table 6-1: Estimated Historic Average Erosion Rates in Southern Monterey Bay Table 6-1
Estimated Historic Long-term Average Erosion Rates (ft/year) in Southern Monterey Bay Location Thornton et al. (2006) Hapke et al. (2006)
1940-1984 1985-2005 1910-2002 1970-2002
Moss Landing +1.2 -1.7
Salinas River +3.7 0
Marina State Beach -1.0 -4.7 -1.4 to -2.0 -3.1 to -5.2 Stilwell Hall (Fort Ord) -5.2 to -6.2 -2.5 to -3.7 -3.7 to -6.6 Sand City -3.9 to -6.4 -2.7 -1.4 -3.7 to -6.2
Monterey Beach Resort -2.4 -0.9 -1.4 -3.0
Del Monte Beach -2.0 -0.4
Rocky cliffs and marine terraces located along Monterey Peninsula from Pacific Grove to Carmel have shown very little erosion over the past several years, with some locations which consist of
granite showing virtually no change over a 50-year time span. 20 The granite cliffs around the entire Monterey Peninsula erode at rates of about 3.3 inches per year. 21 While long-term average erosion in this area is quite low, some years have seen a severe winter storm or series of storms result in 3 to 8 ft of erosion.
22 Steep cliffs within Monterey County are located along the Big Sur coast, where the rugged Santa Lucia Mountains descend abruptly into the Pacific Ocean. Cliff retreat within this area average about 7 inches per year; however, failure rates can be much greater in weakened, fractured, or faulted areas.
23 19 USGS, 2006, National Assessment of Shoreline Change, Part 3. 20 Living with the California Coast, 1985
21 USGS, 2007, National Assessment of Shoreline Change, Part 4. 22 Haro, Kasunich & Associates, 2016, Coastal Bluff Protection Analysis and Geotechnical Investigation for City of Pacific Grove Public Works Department.
23 USGS, 2004, Map Showing Coastal Cliff Retreat Rates Along the Big Sur Coast .
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6.2.2 LOCATION
Coastal erosion is an ongoing process that is difficult to measure but can be seen in various areas along the coastline. Dune and cliff erosion rates vary significantly throughout the County due to geological composition and the physical forces acting on the coastline; therefore, actual erosion and shoreline retreat distance will not be uniform throughout the county.
Coastal erosion is likely across the entire coastline of Monterey County at varying rates. Based on historic erosion rates, Southern Monterey Bay, from Moss Landing to Pacific Grove, is likely to experience the highest rates and largest impacts due to future erosion. While the granite cliffs of the Monterey Peninsula and Big Sur Coast are eroding at a slower rate, they are still vulnerable to erosion during large storm events.
6.2.3 FREQUENCY
Average rates of historic beach and cliff erosion and shoreline retreat and are expected to continue and accelerate, but future erosion rates are difficult to project due to variable coastal processes and uncertainty in sea level rise projections. Increased frequency of coastal storms and wave run-up due to sea level rise increases the irreversible bluff erosion and cliff collapse that may occur.
The entirety of the Monterey County coastline has shown a shift towards increased erosion in the more recent time period. In the Southern Monterey Bay region, the net average retreat rate more than doubles from the long-term (7.8 inches per year) to short-term net retreat of 24 inches per year. In addition, the percent of the coast experiencing erosion increased by 36%. 24 Similar trends have been noticed in the Carmel and Big Sur regions, with net long-term average shoreline change rate being close to undetectable, with a maximum rate of 31 inches per year measured at the southern end of Carmel River State Beach. Short-term erosion occurred along 65% of the coast, with the maximum of 67 inches per year measured at Carmel River State Beach and Carmel City Beach. This indicates that this region is becoming became more erosional from the long-term to the short-term.
25 Actual future rates of erosion are relative to future coastal processes and difficult to project with certainty. Projected rates of erosion are naturally varied and will likely accelerate by 2100; thus, most erosion will occur towards the end of the century. Over the next 50 years, sea level rise in Monterey Bay is predicted to increase coastal erosion 20-25% over historic erosion rates.
In the 50-100-year timeframe, erosion rates are projected to increase 40-50% over historic rates.
26 In the Big Sur region, 5 feet of sea-level rise will expose 2.5 square miles of cliffs and 1.9
24 USGS, 2007, National Assessment of Shoreline Change, Part 4. 25 USGS, 2006, National Assessment of Shoreline Change, Part 3. 26 Association of Monterey Bay Area Governments (AMBAG), 2008, Coastal Regional Sediment Management Plan for Southern Monterey Bay.
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square miles of dunes to erosion, leading to average cliff retreats rates of 121 feet and average dune erosion rates of 590 feet. 27
6.2.4 SEVERITY
Coastal erosion can range from gradual wearing a way of coastal land at inches per year to more significant, catastrophic events that can result in bluff failures involving several hundred cubic yards of material.
The most dramatic erosion often occurs during storms, particularly because the highest energy waves are generated under storm conditions. Although coastal erosion can occur with any annual winter storm, damage is more likely to occur during El Niño events. Ocean storms that have some amount of coastal impact can be expected every year. El Niño events occur about every 2 to 7 years and typically last 16 to 18 months.
Cliff erosion can result in permanent and significant alterations of coastal geology that can expose landward development and resources to additional coastal threats. Large sections of the county coastline, especially those with rocky headlands or sea cliffs, are not vulnerable to flooding, but are highly susceptible to erosion.
6.2.5 WARNING TIME
As discussed previously, coastal erosion can be classified as either episodic or chronic. Episodic erosion consists of the shore and backshore adjustment that results from short duration, high intensity meteorological and oceanic storm events. Meteorologists can often predict the likelihood of a severe weather event. This can give several days of warning time. However, meteorologists cannot predict the exact time of onset or severity of the storm. Some storms may come on more quickly and have only a few hours of warning time. Chronic erosion is associated with slow, gradual shoreline adjustment. Chronic erosion hazards occur slowly but can have significant property or health consequences. The identification of this hazard generally takes site-specific analysis to determine the erosion rates, site soil, geologic properties, and what mitigation is most relevant and prudent for the site. For this type of hazard, warning time is long.
6.3 SECONDARY HAZARDS
Coastal erosion can cause several types of secondary effects. Erosion can destabilize roads, the foundations of structures, and utility lines. It can also cause damage rivers or streams, potentially harming water quality, fisheries, and spawning habitat. Erosion can exacerbate landslide risk, as relentless erosion by ocean waves, creates extreme topography, making areas highly susceptible to landslides. Erosion also exacerbates flood risk, destroying important coastal dunes and cliffs, which provide key flood control benefits.
27 Pacific Institute, California Climate Change Center, 2009, The impacts of sea-level rise on the California coast.
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6.4 RISK ASSESSMENT
USGS Coastal Storm Modeling System (CoSMoS), Central California Projections of Coastal Cliff Retreat and Shoreline Change due to 21st Century Sea Level Rise data was used for this risk assessment. For cliff retreat modeling an end of century (2100) forced sea level rise amount of 200 cm was used based on Ocean Protection Council (OPC) High Risk Aversion Guidance. For shoreline change, winter erosion uncertainty modeling was used to capture the degree of uncertainty associated with future shoreline erosion. Hold the Line scenario modeling was chosen for both types of erosion. Three sea level rise levels (25 cm, 75 cm, and 200 cm) were used to represent planning horizons based on OPC Sea Level Rise Projections for the Monterey Tide Gauge. 25 cm of sea level rise represents near term (2030) risk, 75 cm represent mid-term (2060) risk, and 200 cm represent long-term (2100) risk.
6.4.1 POPULATION
Table 6-2 and Table 6-3 indicates the population in the County exposed to coastal cliff and shoreline erosion risk, respectively.
Table 6-2: Population Exposed to Coastal Cliff Erosion in Monterey County Table 6-2
Population Exposed to Coastal Cliff Erosion Risk in Monterey County Supervisorial
District
Sea Level Rise Scenario
25 CM 75 CM 200 CM
District 1 0 0 0
District 2 0 0 0
District 3 0 0 0
District 4 0 0 0
District 5 1,027 1,642 1,932
Total 1,027 1,642 1,932
Table 6-3: Population Exposed to Shoreline Erosion Risk in Monterey County Table 6-3
Population Exposed to Shoreline Erosion Risk in Monterey County Supervisorial
District
Sea Level Rise Scenario
25 CM 75 CM 200 CM
District 1 0 0 0
District 2 32 32 32
District 3 0 0 0
District 4 34 34 34
District 5 423 147 147
Total 489 213 213
Bluff and cliff failure due to erosion can create hazardous conditions due to roadway collapse, undermined foundations, and damage to utilities. Isolated communities are vulnerable to the impacts, where roadway failure can limit access to basic services for months at a time.
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6.4.2 PROPERTY
Table 6-3 and Table 6-4 indicates the residential property in the County exposed to coastal cliff and shoreline erosion risk, respectively.
Table 6-4: Residential Property Exposed to Coastal Cliff Erosion Risk Table 6-4
Residential Property Exposed to Coastal Cliff Erosion Risk Supervisorial
District
Sea Level Rise Scenario
25 CM 75 CM 200 CM
# Value # Value # Value
District 1 0 0 0 0 0 0
District 2 0 $0 0 $0 0 $0
District 3 0 $0 0 $0 0 $0
District 4 0 $0 0 $0 0 $0
District 5 206 $1,183,367,352 226 $1,244,106,508 253 $1,323,971,611 Total 206 $1,183,367,352 226 $1,244,106,508 253 $1,323,971,611 Table 6-5: Residential Property Exposed to Shoreline Erosion Risk Table 6-5
Residential Property Exposed to Shoreline Erosion Risk
Supervisorial
District
Sea Level Rise Scenario
25 CM 75 CM 200 CM
# Value # Value # Value
District 1 0 0 0 0 0 0
District 2 0 $0 0 $0 0 $0
District 3 0 $0 0 $0 0 $0
District 4 0 $0 0 $0 0 $0
District 5 4 $3,099,857 4 $3,099,857 4 $3,099,857
Total 4 $3,099,857 4 $3,099,857 4 $3,099,857
Table 6-6 and Table 6-7 indicates the non-residential property in the County exposed to coastal cliff and shoreline erosion risk, respectively.
Table 6-6: Non-Residential Property Exposed to Coastal Cliff Erosion Risk Table 6-6
Non-Residential Property Exposed to Coastal Cliff Erosion Risk Supervisorial
District
Sea Level Rise Scenario
25 CM 75 CM 200 CM
# Value # Value # Value
District 1 0 0 0 0 0 0
District 2 0 $0 0 $0 0 $0
District 3 0 $0 0 $0 0 $0
District 4 0 $0 0 $0 0 $0
District 5 226 $221,988,454 227 $223,536,860 248 $240,099,182 Total 226 $221,988,454 227 $223,536,860 248 $240,099,182 COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 6-9 COASTAL EROSION
Table 6-7: Non-Residential Property Exposed to Shoreline Erosion Risk Table 6-7
Non-Residential Property Exposed to Shoreline Erosion Risk Supervisorial
District
Sea Level Rise Scenario
25 CM 75 CM 200 CM
# Value # Value # Value
District 1 0 0 0 0 0 0
District 2 3 $0 2 $0 1 $0
District 3 0 $0 0 $0 0 $0
District 4 0 $122,851,855 32 $122,851,855 27 $116,279,109 District 5 21 $73,218,711 20 $73,218,711 21 $73,729,302 Total 24 $196,070,566 54 $196,070,566 49 $190,008,411
Property vulnerable to coastal erosion, generally includes low-lying coastal structures and those built close to the edge of eroding bluffs. Coastal erosion impacts on coastal property are dependent on several factors including the elevation and composition of the shoreline (i.e., wide sandy beach versus a rocky intertidal beach fronting coastal bluffs).
6.4.3 CRITICAL FACILITIES AND INFRASTRUCTURE
Critical facilities that are vulnerable to coastal erosion may include transportation and wastewater treatment and water supply infrastructure. Regional and local-serving public and utility infrastructure vulnerable to coastal erosion include roads, bridges, railroad lines and crossings, wastewater treatment plants, culverts, water lines, communication line and towers, stormwater outlets, bike lanes, bike facilities, and fiber optic lines. The Seaside Pump Station, the Monterey Interceptor Pipeline between the Seaside Pump Station and Wharf II, and M1W's land/ocean outfall junction structure are all critical facilities identified at high to moderate risk from coastal erosion.
Coastal erosion will have long-lasting impacts on the Monterey Bay region’s transportation infrastructure, threatening over 50 miles of highway, roads, and rail throughout the region including Highway 1. 28 Table 6-8 summarizes transportation infrastructure exposed to both costal cliff and shoreline erosion risk in the County.
Table 6-8: Transportation Infrastructure Exposed to Cliff and Shoreline Erosion Risk Table 6-8
Transportation Infrastructure Exposed to Coastal Cliff and Shoreline Erosion Risk Transportation Infrastructure 1 ft Sea Level Rise
(2030)
3 ft Sea Level Rise
(2060)
7 ft Sea Level Rise
(2100)
Highway/Freeway (Miles) 0 0 0
Major Road (Miles) 71 88 89
Local (Miles) 1 3 8
Railroad (Miles) 0 0 0
28 Pacific Institute, California Climate Change Center, 2009, The impacts of sea-level rise on the California coast.
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6.4.4 ENVIRONMENT
Natural features such as dune fields and coastal cliffs exist over much of the County coastline that are subject to irreversible beach and bluff erosion. A transition between the land and the sea, the shoreline is a critical habitat for nutrient cycling and supports a diversity of invertebrate fauna, surf zone fishes, shorebirds, marine mammals, and plant species, including a Federally Threatened species, such as the Western Snowy Plover.
Sandy beaches and dunes also provide important services to human communities, such as flood protection, serving as barriers to landward shoreline retreat and providing a natural protective buffer against coastal flooding. Normal erosion of coastal dunes provides a significant sediment source for beaches. Sandy beaches also are a significant source of aesthetic, recreational, and economic value to human communities. For example, the Marina sand dunes are breathtaking examples of old dunes covered in coastal scrub and native dune vegetation. Loss of sandy beach and dune habitats would have large environmental effects on Monterey County.
6.4.5 ECONOMIC IMPACT
Tourism is a major economic driver in Monterey County, and future coastal erosion could threaten popular beaches and recreational facilities. Coastal erosion could affect vertical and lateral beach access points, which would prevent residents and visitors from accessing the beach and may increase the risk of injuries. Beach tourism is important to the County’ economy and generates significant revenue as many visitors rent hotels or other accommodations, dine out or shop at area stores. Visitor-serving areas such as those on the Monterey Peninsula and in Big Sur include local businesses and hotels that benefit the local economy. These businesses depend on tourism, and cities and communities within the County benefit from sales tax revenues. Disruption of these areas due to impacts of coastal erosion could decrease economic activity and affect the local economy. Future coastal beach and bluff erosion in the County may also negatively impact coastal businesses and households and decrease coastal real estate opportunities.
Coastal bluff and cliff failure due to coastal erosion can create hazardous conditions due to roadway collapse, undermined home foundations, and damage to utilities. Natural resources with recreational and economic value may also be adversely affected. This risk is notable in the Big Sur area, where roadway failure can limit access to recreational areas for months at a time.
The County supports some of the largest dune habitats in the State, which are vulnerable to damages from erosion. As this vulnerability increases over time, damages may impact the economy of the area and impact viable coastal land uses. Dune erosion along the Monterey Bay is likely to exacerbate the risk of flooding in the lower Salinas Valley. This could increase the risk of flooding on agricultural land and threaten a major economic driver. Coastal storms can also lead to erosion impacts and severe flooding and inundation of economically important infrastructure such as harbors and buildings related to commercial and recreational fisheries.
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6.5 FUTURE TRENDS IN DEVELOPMENT
Land use and development along the County’s shoreline is governed by the California Coastal Act. Regulations under the Coastal Act are typically administered by the County and local cities through adopted Local Coastal Plans (LCP), overseen by the California Coastal Commission. The County and each incorporated city’s certified Local Coastal Plans govern land use planning and development permitting. Monterey County has four LCP segments: North County, Del Monte Forest, Carmel Area, and Big Sur Coast, which guides development in unincorporated areas.
There are also three areas of deferred certification in the County, at Fort Ord Dunes State Park, Mal Paso Beach, and Yankee Point. Each city along the Coast also as a certified Local Coastal Plan which governs land use and permitting with the coastal areas of the cities.
6.6 ISSUES
Key issues associated with coastal erosion in Monterey County include:
• The risk of costal erosion to critically important dune habitat. • The economic risk of coastal erosion on the two largest economic drivers in the County:
agriculture and tourism.
• The cumulative and compounding risk of coastal erosion along with severe winter storms, large storm surge, and wave action along the coastline is likely to lead to more dramatic erosion and exacerbate flooding in low lying areas. • Coastal bluff and cliff failure due to erosion can create hazardous conditions due to roadway collapse, bridge failure, undermined home foundations, and damage to utilities. This can lead to immobility and loss of utilities. • Future sea level rise scenarios are likely to exacerbate coastal erosion risks, but a high degree of uncertainty exists on the future risk.
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7. DAM AND LEVEE FAILURE
7.1 OVERVIEW
7.1.1 DAM FAILURE
A dam is an artificial barrier that stops or restricts the flow of water. Dams are built for a variety of uses including flood protection, power generation, agriculture, water supply, and recreation.
A dam failure is usually the result of the age of the structure, inadequate spillway capacity, or structural damage caused by an earthquake or flood. Dam failures typically occur when spillway capacity is inadequate and excess flow overtops the dam, or when internal erosion (piping) through the dam or foundation occurs. Complete failure occurs if internal erosion or overtopping results in a complete structural breach, releasing a high-velocity wall of debris- filled water that rushes downstream, damaging anything in its path. Improper design, improper maintenance, negligent operation, and/or failure of upstream dams on the same waterway can also cause or contribute to dam failure.
Water released by a failed dam generates tremendous energy and can cause a flood that is catastrophic to life and property. A catastrophic dam failure could challenge local response capabilities and require evacuations to save lives. Impacts to life safety will depend on the warning time and the resources available to notify and evacuate the public. Major loss of life could result as well as potentially catastrophic effects to roads, bridges, and homes. Electric generating facilities and transmission lines could also be damaged and affect life support systems in communities outside the immediate hazard area. Associated water supply, water quality and health concerns could also be an issue. Factors that influence the potential severity
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of a full or partial dam failure are the amount of water impounded; the density, type, and value of development and infrastructure located downstream; and the speed of failure.
7.1.2 LEVEE FAILURE
Levees are man-made structures, usually earthen embankments, designed and constructed to contain, control, or divert a flow of water in order to protect land from peak flood levels or to protect land that is below sea level. Levees reinforce the banks of streams and help prevent flooding by containing higher flow events to the channel. By confining the flow to a narrower steam channel, levees can also increase the speed of the water. Levees provide strong flood protection, but they are not failsafe. Levees are designed to protect against a specific flood level and could be overtopped during severe weather events or dam failure. Levees reduce, not eliminate, the risk to individuals and structures located behind them.
A levee breach occurs when part of a levee gives way, creating an opening through which floodwaters may pass. A breach may occur gradually or suddenly. The most dangerous breaches happen quickly during periods of high water. The resulting torrent can quickly swamp a large area behind the failed levee with little or no warning. When a levee system fails or is overtopped, severe flood damage can occur due to increased water surface elevation associated with levees and the resulting increase in water velocity.
Earthen levees can be damaged in several ways. For instance, strong river currents and waves can erode the surface. Trees growing on a levee can blow over, leaving a hole where the root wad and soil used to be. Burrowing animals, such as the California ground squirrel, the salt marsh harvest mouse, or the western burrowing owl can create holes that enable water to pass through a levee. If severe enough, any of these situations can lead to a zone of weakness that could cause a levee breach. In seismically active areas, earthquakes and ground shaking can cause a loss of soil strength, weakening a levee and possibly resulting in failure. Seismic activity can also cause levees to slide or slump, both of which can lead to failure. No levee provides protection from events for which it was not designed, and levees require maintenance to continue to provide the level of protection they were designed and built to offer.
7.1.3 REGULATORY OVERSIGHT
National Dam Safety Act
Potential for catastrophic flooding due to dam failures led to passage of the National Dam Safety Act (Public Law 92-367). The National Dam Safety Program requires a periodic engineering analysis of most dams in the country. The goal of this FEMA-monitored effort is to identify and mitigate the risk of dam failure in order to protect lives and property of the public.
The National Dam Safety Program is a partnership among the states, federal agencies, and other stakeholders that encourages individual and community responsibility for dam safety.
Under FEMA’s leadership, state assistance funds have allowed all participating states to improve their programs through increased inspections, emergency action planning, and COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 7-3 DAM AND LEVEE FAILURE
purchases of needed equipment. FEMA has also expanded existing and initiated new training programs. Grant assistance from FEMA provides support for improvement of dam safety programs that regulate most of the dams in the United States.
California Division of Safety of Dams
California’s Division of Safety of Dams (DSOD), a division of the Department of Water Resources (DWR), monitors dam safety at the state level. Dams regulated by the DSOD are more than 25 feet in height and hold back more than 15 acre-feet of water or are more than 6 feet in height and hold more than 50 acre-feet of water. DSOD assigns hazard ratings to large dams within the State. Dams are classified in four categories based on the potential hazard to life and property:
• Extremely High Hazard – Expected to cause considerable loss of human life or would result in an inundation area with a population of 1,000 or more. • High Hazard – Expected to cause loss of at least one human life. • Significant Hazard – No probable loss of human life but can cause economic loss, environmental damage, impacts to critical facilities, or other significant impacts. • Low Hazard – No probable loss of human life and low economic and environmental losses. Losses are expected to be principally limited to the owner’s property.
Federal Energy Regulatory Commission Dam Safety Program The Federal Energy Regulatory Commission (FERC) cooperates with many federal and state agencies to ensure and promote dam safety. More than 3,000 dams are part of regulated hydroelectric projects in the FERC program. Two-thirds of these are more than 50 years old. As dams age, concern about their safety and integrity grows, so oversight and regular inspection are important. FERC inspects hydroelectric projects on an unscheduled basis to investigate potential dam safety problems, complaints about constructing and operating a project, safety concerns related to natural disasters, and issues concerning compliance with the terms and conditions of a license.
Every five years, an independent engineer approved by the FERC must inspect and evaluate projects with dams higher than 32.8 feet (10 meters), or with a total storage capacity of more than 2,000 acre-feet. FERC monitors seismic research and applies it in performing structural analyses of hydroelectric projects. FERC also evaluates the effects of potential and actual large floods on the safety of dams. During and following floods, FERC visits dams and licensed projects, determines the extent of damage, if any, and directs any necessary studies or remedial measures the licensee must undertake.
FERC requires licensees to prepare emergency action plans and conducts training sessions on how to develop and test these plans. The plans outline an early warning system if there is an actual or potential sudden release of water from a dam due to failure. The plans include operational procedures that may be used, such as reducing reservoir levels and reducing downstream flows, as well as procedures for notifying affected residents and agencies responsible for emergency management.
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US Army Corps of Engineers Dam Safety Program
The US Army Corps of Engineers is responsible for safety inspections of some federal and nonfederal dams in the US that meet the size and storage limitations specified in the National Dam Safety Act. They have inventoried such dams and surveyed each state and federal agency’s capabilities, practices, and regulations regarding design, construction, operation, and maintenance of the dams.
US Army Corps of Engineers and FEMA Levee Oversight
The Army Corp and FEMA have differing roles and responsibilities related to levees. The Corps addresses operation and maintenance, risk communication, risk management, and risk reduction issues as part of its responsibilities under the Levee Safety Program. FEMA addresses mapping and floodplain management issues related to levees, and it accredits levees as meeting requirements set forth by the National Flood Insurance Program.
Depending on the levee system, the Corps and FEMA may be involved with a levee sponsor and community independently or jointly. The two agencies’ long-term goals are similar: to reduce risk and lessen the devastating consequences of flooding. Army Corps and FEMA partnering activities related to levees include the following:
• Joint meetings with levee sponsors and other stakeholders • Integration of levee information into the National Levee Database • State Silver Jackets teams
• Sharing of levee information
• Targeted task forces to improve program alignment.
Coordination between the Corps and FEMA on levees is now standard within many of each agency’s policies and practices. Over the past several years, both agencies coordinated policies where appropriate; jointly participated in meetings with stakeholders; and participated in many multiagency efforts, such as the National Committee on Levee Safety, the Federal Interagency Floodplain Management Task Force, and the Silver Jackets Program, which brings together state, federal, tribal, and local agencies to learn from each other and apply their knowledge to reduce risk from hazards.
National Committee on Levee Safety
Congress created the National Committee on Levee Safety to develop recommendations for a national levee safety program. The Committee notes that when combined, aging levees, increased development in the floodplain, and increasing frequency of flooding due to climate change, point to an overall increase in the risk of flooding due to levee overtopping or failure.
The Committee seeks to use an integrated approach to creating reliable levee systems and protecting people and property from floods. The Committee is made up of representatives from the Army Corps, FEMA, state, regional, and local agencies, and the private sector and has been working toward this goal since October 2008.
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7.1.4 DAMS IN MONTEREY COUNTY
The following dams are located in or have inundation zones in Monterey County:
Table 7-1: Dams in or Owned by Monterey County
Table 7-1
Dams in or Owned by Monterey County*
Facility
Name
Water
Course Owner Dam Type Downstream
Hazard Condition
San Antonio San Antonio
River
Monterey County
Water Resources
Agency
Earthen
Embankment
Extremely
High Fair
Los Padres Carmel
River
California
American Water
Earthen
Embankment
Extremely
High Satisfactory
Pacific Grove Pacific
Ocean
California
American Water
Earthen
Embankment Low Satisfactory
Forest Lake Off stream
Pebble Beach
Community
Services District
Earthen
Embankment
Extremely
High Satisfactory
Black Rock
Creek
Black Rock
Creek Private Earth and
Rock Low Satisfactory
Silacci Unnamed Private Earthen
Embankment Significant Fair
Nacimiento1 Nacimiento
River
Monterey County
Water Resources
Agency
Earthen
Embankment
Extremely
High Satisfactory
*Excludes Federally owned Dams
1Located in San Luis Obispo County
Source: Division of Safety of Dams, Dams Within Jurisdiction of the State of California For the purposes of this Plan, the Nacimiento, San Antonio, Forest Lake, and Los Padres dams will be discussed in more detail as they pose an Extremely High downstream hazard and are considered by FEMA as High Hazard Potential Dams (HHPD).
Nacimiento Dam
Nacimiento Dam and its reservoir, the Nacimiento Reservoir, are located in northern San Luis Obispo County, about 20 miles from the coast, in central California. This earth-filled dam was completed in 1957.When the reservoir is full (elevation 800 feet), it has a maximum storage capacity of 377,900 acre-feet, is 18 miles long, and has about 165 miles of shoreline. The maximum elevation during flood stage is 825 feet, with a maximum temporary capacity of 538,000 acre-feet and a temporary surface area of 7,149 acres. Nacimiento Dam is under the jurisdiction of the DWR DSOD and the FERC. The FERC has jurisdiction over the project due to the existence of the hydroelectric plant. Nacimiento Dam was constructed and is owned by the COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 7-6 DAM AND LEVEE FAILURE
Monterey County Water Resources Agency (MCWRA). It serves as a flood control, water conservation, and recreation facility.
For the purposes of this plan, the following relevant plans, and studies specific to the Nacimiento Dam were reviewed:
• Nacimiento Dam EAP; WRA Rev #3 12/17/2021
• Nacimiento Dam Spillway Condition Assessment Report; GEI 2018 • Nacimiento Dam construction documentation
• Nacimiento Dam periodic inspection reports
• Nacimiento Dam FERC Part 12D Potential Failure Mode Analysis Reports • Nacimiento Dam FERC Part 12D Safety Inspection Reports • Nacimiento Dam Seismic Stability Review Report; GEI 2005 • Nacimiento Dam Safety Surveillance and Monitoring Reports • Probable Maximum Flood Hydrology Report for Nacimiento Reservoir and Supplements; GEI 2001, 2003, and 2004
San Antonio Dam
San Antonio Dam and its reservoir, the San Antonio Reservoir, are located in southern Monterey County, about 16 miles northwest of Paso Robles, in central California. This earth- filled dam was completed in 1967. When the reservoir is full (elevation 780 feet), it has a maximum storage capacity of 335,000 acre-feet, is 16 miles long, and has about 100 miles of shoreline. The maximum elevation during flood stage is 802 feet, with a maximum temporary capacity of about 477,000 acre-feet and a temporary surface area of about 7,500 acres. San Antonio Dam is under the jurisdiction of the DSOD. Like Nacimiento Dam, San Antonio Dam was constructed and is owned by the MCWRA. It serves as a flood control, water conservation, and recreation facility.
For the purposes of this plan, the following relevant plans, and studies specific to the San Antonio Dam were reviewed:
• San Antonio Dam Spillway Condition Assessment Report; GEI 2018 • San Antonio Dam construction documentation
• San Antonio Dam periodic inspection reports
• San Antonio Dam Performance Evaluation Reports
• San Antonio Dam Seismic Analysis Report; Bechtel 1970 • Probable Maximum Flood Hydrology Report for San Antonio Reservoir; GEI 1999 Forest Lake Dam
The Forest Lake Dam, and its reservoir, the Forest Lake Reservoir, is in the Pebble Beach area in the Del Monte Forest. In December 1998, the Pebble Beach Community Services District (PBCSD) purchased the Forest Lake Reservoir from California-American Water Company (Cal- Am). Following the purchase, the reservoir was rehabilitated, including new improvements to COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 7-7 DAM AND LEVEE FAILURE
meet the DSOD requirements. During winter months, when there is excess production at the Carmel Area Wastewater District’s treatment plant, the reservoir is filled with recycled water.
Stored recycled water is then used during summer months when the irrigation demands exceed the production, thereby further reducing the use of potable water. The rehabilitation of the reservoir started in 2005 and completed in 2006. In 2009, outlet structure of the reservoir was modified to increase the storage capacity from 105 million gallons to 115 million gallons.
Los Padres Dam
The Los Padres Dam, built in 1949 along the Carmel River, is located 25 miles upstream from the ocean. The dam is a rock and earth-filled dam which is as high as a thirteen-story building; its base is as thick as a football field and has an overall crest measurement of 680 feet. The dam is owned and operated by California-American Water Company (Cal-Am) and serves as a flood control and water conservation facility. The reservoir has a 3,200-acre feet of storage capacity.
The Los Padres Reservoir is steadily filling with sediment, as the pervasively fractured granitic and metamorphic rock underlying the Carmel River watershed is easily eroded.
Sediment loads may greatly increase when fires reduce vegetation cover and are followed by large rainfall events, as occurred after the 1977 Marble Cone Fire that produced catastrophic debris flows. The Monterey Peninsula Water Management District (MPWMD) has undertaken several studies that fully evaluate the various options available for Los Padres Dam. The studies include consideration of dam removal and the development of new location for water storage "off-mainstem" of the Carmel River. This alternative was determined to best meet the long- term needs of water supply, instream flows, and fish passage within the watershed and represented the most effective means of maximizing beneficial use of the basin's available hydrology.
7.1.5 LEVEES IN MONTEREY COUNTY
Monterey County contains about 52 linear miles of levees. Most levees in the County are privately owned agricultural levees. Table 7-2 summarizes levee miles by waterway.
Table 7-2: Miles of Levee in Monterey County by Waterbody Table 7-2
Miles of Levee in Monterey County by Waterbody
Waterbody Miles of Levee
Bennett Slough 0.9
Carmel River 2.1
Elkhorn Slough 5.6
Moro Cojo Slough 4.3
Pajaro River 9.2
Salinas River 29.6
Total 51.7
Source: US Army Corp of Engineers, National Levee Database
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Pajaro River Levee
The Pajaro River is located in Santa Cruz and Monterey County with the River being the approximate County line. The Pajaro River Levee System was built as a federal flood control project, authorized by Section 10 of the Flood Control Act of December 1944. The Army Corps of Engineers designed and constructed the levees and associated system components within the Pajaro River Basin in the late 1940s. The project was built to reduce flood risk to the City of Watsonville, the town of Pajaro and surrounding areas by reducing flooding over the channel banks. The project primarily consists of earthen levees, with a low flow channel. The low flow channel varies in elevation but is typically about 25 feet below the levee crest elevation.
The left (southern) bank of the Pajaro Levee system is located in Monterey County and extends from the Pacific Ocean to Murphy Road. The town of Pajaro is located behind the left bank levee. The levee maintenance agency for the left bank is the MCWRA. MCWRA has an emergency plan that identifies critical stages of the river and the related actions that the Office of Emergency Services takes such as declaring an emergency and mobilizing emergency responders. The MCWRA also has an ALERT system that monitors river levels whenever significant storms approach the area.
The right (northern) bank of the Pajaro River Levee system is owned/operated by the Santa Cruz County Flood Control and Water Conservation District – Zone 7. Santa Cruz County, Zone 7, and the City of Watsonville have an Emergency Action Plan. The County can monitor stream gages and when a critical water level is reached, alert the public through a reverse 911 system.
The County also has an evacuation plan that covers a range of disasters and an ALERT Storm System.
Carmel River Levees
Levees have been constructed by private interests on the Carmel River from State Highway 1 upstream approximately 4,000 feet on the north bank, and from 3,000 feet upstream of the mouth to 10,000 feet upstream of the mouth on the south bank. These levees are not adequate to hold the 100-year flood.
7.2 HAZARD PROFILE
7.2.1 HISTORY
Dam Failure
There is no record of any damages, fatalities, or injuries associated with dam failure in the Monterey County. However, water has been released over the Nacimiento Dam spillway crest five times (1958, 1969, 1983, 2011, and 2017) over the last 63 years, and the San Antonio Dam spillway crest three times (1982, 1983, and 2006) over the past 55 years.
The state’s most recent dam emergency occurred in February 2017 when the Oroville Dam in Butte County was on the verge of overflow. The dam’s concrete spillway was damaged by erosion and a massive hole developed. The auxiliary spillway was used to prevent overtopping COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 7-9 DAM AND LEVEE FAILURE
of the dam, and it experienced erosion problems
also. Evacuation orders were issued in advance of a
potential large uncontrolled release of water from
Lake Oroville, but such a release did not occur.
After this incident, state officials ordered that the
flood-control spillways of 93 dams be re-inspected
for potential geologic, structural, or performance
issues that could jeopardize their ability to safely
pass a flood event.
Levee Failure
In March 1995, a 10–20-year storm event, caused a
breach in the Pajaro levee approximately 3 miles
upstream of the town of Pajaro. The drainage
system in the flat town could not adequately
discharge the stormwater runoff in the streets. This
resulted in mass evacuations and damage to private
property. All residences (600+) and businesses in
Pajaro were damaged and 2,500 people were
evacuated.
Several locations along the Pajaro Levee were
damaged and had to be repaired after the 1989
Loma Prieta earthquake causing damage to roads
and property. An atmospheric river event in
January of 2017 caused a levee breach along the
Carmel River near Paso Hondo in Carmel Valley
Village, impacting 20 to 30 homes.
7.2.2 LOCATION
Dam Failure
A dam failure is possible at any dam in Monterey
County. The most likely location of a damaging
levee failure would be at dams classified as having
extremely high downstream hazard, which as
previously mentioned includes the Nacimiento, San
Antonio, Forest Lake, and Los Padres Dams.
The Nacimiento, San Antonio, and Los Padres Dams
are older and are the most likely locations of a dam
failure.
Mitigation Success Story
San Clemente Dam Removal
The San Clemente Dam was a large concrete
dam located about 18 miles from the Ocean
on the Carmel River. Over time the reservoir
became increasingly sedimented and no
longer served as a water source. The dam
posed a safety concern and could have failed
in the event of a large earthquake or flood.
Due to safety a nd environmental concerns,
the CA Coastal Conservancy, NOAA , and
California American Water decided to re -
route the river and remove the d am. As of
2019, the Carmel River is returning to its wild
state and the fish population is rebounding.
At the time, this was the largest dam removal
project in California history.
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All three dams and reservoirs are inspected annually by the DSOD to ensure that they are in good operating condition. Nacimiento receives an additional annual inspection from FERC. Both Nacimiento and San Antonio receive periodic inspections by Water Resource Agency staff.
These dam safety programs reduce risk associated with the dams but do not eliminate the possibility of a dam failure. During the winter, temporary flood storage is provided in flood pools in Nacimiento and San Antonio reservoirs.
Along the Los Padres Dams, excess water can be released through transmission pipes, valves, and spillway systems. However, use of the dam spillways for flood control releases would most likely occur during severe winter storms, when the dams and reservoirs are receiving increased inflow. Damage from a dam failure is most likely to occur in mapped dam failure inundation zones. Shown in Figure 7-1 is the dam failure inundation zones for a spillway or full dam failure at the Nacimiento Dam.
Figure 7-1
Nacimiento Dam Failure Inundation Zone
Figure 7-1: Nacimiento Dam Failure Inundation Zone
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As of April 2019, the San Antonio Dam spillway has been identified to have significant foundation and structural deficiencies such that the spillway is in poor condition and unsafe for use under high flow conditions. Major rehabilitation or full replacement of the spillway will be needed to ensure the safe performance of the spillway under significant flows up to the maximum design outflow. The California Department of Water Resources, Division of Safety of Dams requires the San Antonio dam spillway be restored to full function by November 1, 2024.
Shown in Figure 7-2 is the dam failure inundation zones for a spillway or full dam failure at the San Antonio Dam.
Figure 7-2
San Antonio Dam Failure Inundation Zone
Figure 7-2: San Antonio Dam Failure Inundation Zone
The inundation zones for both the Los Padres Dam and the Forest Lake Dam are mapped in Figure 7-3.
COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 7-12 DAM AND LEVEE FAILURE
Figure 7-3
Los Padres and Forest Lake Dam Failure Inundation Zones
Figure 7-3: Los Padres and Forest Lake Dam Failure Inundation Zones Levee Failure
A levee failure is possible along any levee in Monterey County. The most likely location of a damaging levee failure would be at the Carmel River Levees, the Pajaro River Levee, or at one of the many levees along the Salinas River.
For the NFIP, FEMA only recognizes levee systems that meet minimum design, operation, and maintenance standards. Therefore, there is a possibility that unaccredited levees exist in Monterey County, which do not meet FEMA standards and that could be a location of a levee failure. Since information is not available on the locations of such levees, risk associated with unaccredited levees is beyond the scope of this plan.
Levee miles and leveed area in Monterey County is shown in Figure 7-4.
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Figure 7-4
Levees in Monterey County
Figure 7-4: Levees in Monterey County
7.2.3 FREQUENCY
Dam Failure
Dam failure events are infrequent and usually coincide with events that cause them, such as earthquakes, landslides, and excessive rainfall and snowmelt. Although the recent Oroville event raised public concern about dam failure, the probability of such failures remains low in today’s regulatory environment.
All dams face a “residual risk” of failure, which represents the risk that conditions may exceed those for which the dam was designed. For example, dams may be designed to withstand a probable maximum precipitation, defined as the theoretically, greatest depth of precipitation for a given duration that is physically possible over a given storm area at a particular geographical location at a certain time of the year. The chance of occurrence of a precipitation event of a greater magnitude than that represents residual risk for such dams. This in turn represents a theoretical probability of future occurrence for a dam failure event, though the
COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 7-14 DAM AND LEVEE FAILURE
probability of an event exceeding the assumed maximum is not generally calculated as part of dam design.
Levee Failure
Levee failure probabilities are considered to be higher than dam failure probabilities because levees are often exposed to more adverse conditions associated with high velocity flood flows, such as erosion and scour. Many levees are designed to overtop in high flow conditions; such overtopping is referred to as design failure.
7.2.4 SEVERITY
Dam Failure
Dam failure can be catastrophic to all life and property downstream. The US Army Corps of Engineers developed the classification system shown in Table 7-3 for the hazard potential of dam failures.
Table 7-3: US Army Corps of Engineers Dam Hazard Potential Classification Table 7-3
US Army Corps of Engineers Dam Hazard Potential Classification Hazard
Category Direct Loss of Life Lifeline & Property Losses Environmental Losses Low None expected
No disruption of services; Loss of
isolated buildings, agricultural
lands, and equipment
Minimal incremental
damage
Significant None expected
Disruption of essential facilities and
access; major loss of public and
private facilities
Major mitigation
required
High Probable. One or
more expected
Disruption of essential facilities and
access; Extensive loss of public and
private facilities
Extensive or
impossible to mitigate
The Army Corps has classified the Forest Lake, Los Padres, San Antonio, and Nacimiento Dams as High Hazard
29 Dam inundation maps show that the greatest risk from dam failure is in Carmel Valley, where failure of the Los Padres would cause inundation of urbanized areas and alter the riparian corridor. Dam failure in Salinas Valley would also be significant, whether caused by the failure of San Antonio or Nacimiento Reservoir. Studies reveal that either failure would overflow the 100-year floodplain in Salinas Valley. However, the risk would predominately be to agricultural land.
Levee Failure
In the event of a levee failure, floodwaters may ultimately inundate the protected area landward of the levee. The extent of inundation is dependent on the flooding intensity. Failure of a levee during a 1% annual chance flood will inundate the 100-year floodplain previously
29 US Army Corp of Engineers, National Inventory of Dams COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 7-15 DAM AND LEVEE FAILURE
protected by the levee. Residential and commercial buildings nearest the levee overtopping or breach location will suffer the most damage from the initial embankment failure flood wave.
Landward buildings will be damaged by inundation.
One major risk for the Pajaro River levee is of a breach before water flows over the levee (overtopping). This breach is associated with seepage (water leaking through the levee) and resulting erosion of the levee slope. The other major risk is from overtopping (water flowing over the levee) which also results in levee erosion and the potential for a breach. If a breach occurs, water could flood the town of Pajaro and surrounding agricultural lands rapidly, leading to significant economic damage and potential loss of life. While these conditions are possible, they are not certain to take place during a flood event. The past evacuations and flood events have increased community awareness and reduced the likelihood for life loss through the implementation of the notification and evacuation plans.
7.2.5 WARNING TIME
Dam Failure
Warning time for dam failure varies depending on the cause of the failure, the size of the dam and volume of water retained, and the location of the dam. In events of extreme precipitation or massive snowmelt, evacuations can be planned with sufficient time. In the event of a structural failure due to earthquake, there may be no warning time. A dam’s structural type also affects warning time. All dams of concern in Monterey County are earthen dams, which do not tend to fail completely or instantaneously. Once a breach is initiated, discharging water erodes the breach until either the reservoir water is depleted, or the breach resists further erosion. The time of breach formation ranges from a few minutes to a few hours.
The number of people to be alerted and evacuated in the event of impending dam failure can vary widely. A major factor to consider is the initial flow in the river when the failure occurs.
The initial flow is normally very low on all the rivers between May and October. During the winter, the initial flow is much higher. This wide variation in initial flow has a significant impact on the areas that must be evacuated.
Levee Failure
Warning time for levee failures depends on the cause of the failure. A levee failure caused by structural failure can be sudden and occur with little to no warning. If heavy rains are impacting a levee system, communities located in the immediate danger zone can be evacuated before a failure occurs. If the levee failure is caused by overtopping, the community may or may not be able to recognize the impending failure and evacuate. If a levee failure occurs suddenly, evacuation may not be possible.
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7.3 SECONDARY HAZARDS
Dam and levee failure can cause severe downstream flooding, depending on the magnitude of the failure. Other potential secondary hazards are landslides, bank erosion, and destruction of downstream habitat. Levee failures can also cause environmental incidents due to hazardous materials releases when floodwaters infiltrate facilities that store these types of materials.
Additionally, dam failure may worsen the severity of a drought by releasing water that might have been used as a potable water source. A failure of the Nacimiento or San Antonio dam could affect water availability for downstream agricultural users. If the dams were to fail or otherwise be unable to provide regular water releases, it would affect the ability of growers to exercise their right to those surface waters for supplementing recycled water and could cause a corresponding increase in groundwater usage.
7.4 RISK ASSESSMENT
For the purposes of this risk assessment, dam failure risk was assessed for the dams that are classified as High Hazard by the Army Corps of Engineers, which includes the Nacimiento, San Antonio, Forest Lake, and Los Padres Dams. Inundation zone data for the Nacimiento and San Antonio dams were provided by MCWRA. Inundation data for the Forest Lake Dam were provided by the Pebble Beach Community Services District. Inundation data for the Los Padres Dam were from the DWR DSOD California Dam Inundation Map data.
Data on levee location, leveed area, and population and property exposed to levee failure risk were from the US Army Corp of Engineers, National Levee Database. Leveed Area, which is defined as the estimated area of a floodplain from which flood water is excluded by the levee system, was used to determine the population and property exposed to levee failure.
7.4.1 POPULATION
Dam Failure
All residents in a dam failure inundation zone would be exposed to the risk of a dam failure.
Population exposed to a failure of the Nacimiento Dam is summarized in Table 7-4.
Table 7-4: Population Exposed to Dam Failure - Nacimiento Dam Table 7-4
Population Exposed to Dam Failure in Monterey County- Nacimiento Dam Supervisorial District Spillway Failure Dam Failure
District 1 0 0
District 2 4,391 6,876
District 3 3,779 7,427
District 4 1,493 11,372
District 5 2,690 3,091
Total 12,353 28,766
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Population exposed to a failure of the San Antonio Dam is summarized in Table 7-5.
Table 7-5: Population Exposed to Dam Failure - San Antonio Dam Table 7-5
Population Exposed to Dam Failure in Monterey County- San Antonio Dam Supervisorial District Spillway Failure Dam Failure
District 1 0 0
District 2 2,509 5,757
District 3 1,024 7,742
District 4 174 9,318
District 5 66 3,090
Total 3,773 25,907
A failure of the Los Padres Dam would impact a population of 5,784, all located in Monterey County Supervisorial District 5, in the Carmel Valley area.
Population exposed to a failure of the Forest Lake Dam is summarized in Table 7-6. Impacts are not summarized by Supervisorial District, as all impacts would occur in Monterey County Supervisorial District 5 in the Pebble Beach community.
Table 7-6: Population Exposed to Dam Failure - Forest Lake Dam Table 7-6
Population Exposed to Dam Failure in Monterey County- Forest Lake Dam Scenario Population
Scenario 1- North Embankment Failure 302
Scenario 2- South Embankment Failure 403
Scenario 3- Outlet Structure Failure 23
Scenario 4- NW End of South Embankment Failure 834
The potential for loss of life is affected by the capacity and number of evacuation routes available to those living in potential inundation areas. Vulnerable populations are all populations downstream from dam failures that are incapable of escaping the area within the allowable time frame. This population includes the elderly and young who may be unable to get themselves out of the inundation area.
The vulnerable population also includes those who would not have adequate warning from a television or radio emergency warning system.
Levee Failure
Those living in an area protected by a levee would be exposed to levee failure risk in the event of a levee failure event.
Table 7-7 summarizes population exposed to levee failure risk by water body in Monterey County.
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Table 7-7: Population Exposed to Levee Failure by Waterbody Table 7-7
Population Exposed to Levee Failure in Monterey County by Waterbody Waterbody Miles of Levee Population
Bennett Slough 0.9 6
Carmel River 2.1 633
Elkhorn Slough 5.6 0
Moro Cojo Slough 4.3 0
Pajaro River 9.2 3,597
Salinas River 29.6 23
Total 51.7 4,259
Source: US Army Corp of Engineers, National Levee Database A failure of the left (southern) bank of the Pajaro levee would threaten the population of the town of Pajaro, which includes a population of 2,700 to 3,600 people who are located within the floodplain with the higher number of populations at night. There is also potential for loss of life from levee breaching.
Similar to dam failure, vulnerable populations are all populations in a leveed area that are incapable of escaping the area within the allowable time frame. This population includes the elderly and young who may be unable to get themselves out of the inundation area. The vulnerable population also includes those who would not have adequate warning from a television or radio emergency warning system. Homeless encampments are sometimes located along levees and those populations would be immediately vulnerable if a levee were to fail.
7.4.2 PROPERTY
Dam Failure
All property in a dam failure inundation zone would be exposed to the risk of a dam failure.
Residential property exposed to a failure of the Nacimiento Dam is summarized by failure type in Table 7-8. Non-residential property exposed to a failure of the Nacimiento Dam is summarized by failure type in Table 7-9.
Table 7-8: Residential Property Exposed to Dam Failure - Nacimiento Dam Table 7-8
Residential Property Exposed to Dam Failure in Monterey County- Nacimiento Dam Supervisorial
District
Spillway Failure Dam Failure
# Value # Value
District 1 0 $0 0 $0
District 2 102 $64,518,030 547 $215,959,574
District 3 350 $111,015,165 930 $296,389,365
District 4 18 $7,953,691 2,449 $1,085,984,861
District 5 18 $6,264,905 201 $119,647,543
Total 488 $189,751,791 4,127 $1,717,981,343
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Table 7-9: Non-Residential Property Exposed to Dam Failure - Nacimiento Dam Table 7-9
Non-Residential Property Exposed to Dam Failure in Monterey County- Nacimiento Dam Supervisorial
District
Spillway Failure Dam Failure
# Value # Value
District 1 0 $0 0 $0
District 2 1,573 $284,272,763 1,739 $359,562,190
District 3 601 $1,046,736,191 1,237 $1,913,669,147
District 4 212 $318,310,350 1,081 $652,433,746
District 5 81 $75,470,973 149 $97,208,521
Total 2,467 $1,724,790,277 4,206 $3,022,873,604
Residential and non-residential property exposed to a failure of the San Antonio Dam is summarized by failure type in Table 7-10 and Table 7-11, respectively.
Table 7-10: Residential Property Exposed to Dam Failure- San Antonio Dam Table 7-10
Residential Property Exposed to Dam Failure in Monterey County- San Antonio Dam Supervisorial
District
Spillway Failure Dam Failure
# Value # Value
District 1 0 $0 0 $0
District 2 25 $14,955,579 356 $160,541,542
District 3 27 $3,896,226 862 $290,548,892
District 4 6 $1,878,279 1,829 $817,783,466
District 5 5 $1,925,278 270 $158,562,338
Total 63 $22,655,362 3,317 $1,427,436,238
Table 7-11: Non-Residential Property Exposed to Dam Failure- San Antonio Table 7-11
Non-Residential Property Exposed to Dam Failure in Monterey County- San Antonio Dam Supervisorial
District
Spillway Failure Dam Failure
# Value # Value
District 1 0 $0 121 $81,861,626
District 2 1,365 $163,566,067 1,709 $344,429,789
District 3 458 $708,840,660 1,226 $1,603,644,752
District 4 84 $156,648,583 883 $570,421,330
District 5 47 $60,066,878 164 $99,018,359
Total 1,954 $1,089,122,188 4,103 $2,699,375,856
A failure of the Los Padres Dam would impact 943 residential properties, valued at $779,795,548 and 419 non-residential properties, valued at $196,382,343. All impacted property would be in Monterey County Supervisorial District 5, in the Carmel Valley area.
Residential property exposed to a failure of the Forest Lake Dam by failure type is summarized in Table 7-12. Non-residential property exposed to a failure of the Forest Lake Dam by failure COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 7-20 DAM AND LEVEE FAILURE
type is summarized in Table 7-13. Impacts are not summarized by Supervisorial District, as all impacts would occur in Supervisorial District 5 in the Pebble Beach community.
Table 7-12: Residential Property Exposed to Dam Failure - Forest Lake Dam Table 7-12
Residential Property Exposed to Dam Failure in Monterey County- Forest Lake Dam Scenario Number Value
Scenario 1- North Embankment Failure 38 $47,663,347
Scenario 2- South Embankment Failure 48 $54,833,015
Scenario 3- Outlet Structure Failure 0 $0
Scenario 4- NW End of South Embankment Failure 266 $356,389,582 Table 7-13: Non-Residential Property Exposed to Dam Failure - Forest Lake Dam Table 7-13
Non-Residential Property Exposed to Dam Failure in Monterey County- Forest Lake Dam Scenario Number Value
Scenario 1- North Embankment Failure 12 $97,873,581
Scenario 2- South Embankment Failure 16 $62,584,773
Scenario 3- Outlet Structure Failure 0 $0
Scenario 4- NW End of South Embankment Failure 52 $77,207,153 Vulnerable properties are those closest to the dam inundation area. These properties would experience the largest, most destructive surge of water. Low-lying areas are also vulnerable since they are near where the dam waters would collect. Properties in the dam inundation zone that are built to NFIP minimum construction standards may have some level of protection against dam inundation, depending on the velocity and elevation of the inundation waters.
These properties also are more likely to have flood insurance.
Levee Failure
Any property in an area protected by a levee would be exposed to levee failure risk in the event of a levee failure event. Table 7-14 summarizes land area behind levees, as well as structures and property value exposed to levee failure risk by water body in Monterey County.
Table 7-14: Property Exposed to Levee Failure by Waterbody Table 7-14
Property Exposed to Levee Failure in Monterey County by Waterbody Waterbody Miles of Levee Leveed Area in
Square Miles Structures Property Value
Bennett Slough 0.9 0.35 1 $544,000
Carmel River 2.1 0.17 111 $258,000,000
Elkhorn Slough 5.6 0.62 0 $0
Moro Cojo Slough 4.3 0.87 0 $0
Pajaro River 9.2 5.97 811 $481,000,000
Salinas River 29.6 8.51 8 $55,501,000
Total 51.7 16.49 931 $795,045,000
Source: US Army Corp of Engineers, National Levee Database COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 7-21 DAM AND LEVEE FAILURE
The southern bank of the Pajaro levee reduces flood risk for agricultural areas and the town of Pajaro which sits within the floodplain. There is potential for high economic damages if a levee breach occurs and 800 structures at risk of flooding. While not all land protected by levee is agricultural, much of the 16.49 square miles of the land protected by levees in Monterey County is likely agricultural. Therefore, a levee failure could threaten important agricultural value.
7.4.3 CRITICAL FACILITIES AND INFRASTRUCTURE
Dam Failure
Transportation routes have the potential to be destroyed due to dam failure. This includes all roads, railroads, and bridges in the path of the dam inundation. Notably, Highway 101 would be at risk if the Nacimiento or San Antonio Dam were to fail. Carmel Valley Road would be at risk due to a failure of the Los Padres Dam.
Transportation routes vulnerable to dam inundation have the potential to be wiped out and could create isolation issues. Those that are most vulnerable are those that are already in poor condition and would not be able to withstand a large water surge.
Utilities such as overhead power lines, cable and phone lines could also be at risk if any dam were to fail. Loss of these utilities could create additional isolation issues for the inundation areas. Table 7-15 summarizes critical infrastructure identified as vulnerable to dam failure risk.
Table 7-15: Critical Infrastructure Exposed to Dam Failure Risk Table 7-15
Critical Infrastructure Exposed to Dam Failure Risk in Monterey County Critical Infrastructure
Type
Nacimiento San Antonio Forest Lake
(Scenarios) Los
Padres Dam
Failure
Spillway
Failure
Dam
Failure
Spillway
Failure 1 2 3 4
Facilities
Emergency Response 4 0 1 0 0 0 0 0 0
Fire Station 3 0 1 0 0 0 0 0 1
Police Station 2 0 2 0 0 0 0 0 0
Medical Facilities 4 0 4 0 0 0 0 0 2
Military Facility 0 0 0 0 0 0 0 0 0
Large Public Facility 0 0 0 0 0 0 0 0 0
Educational Facilities 12 0 6 0 0 0 0 0 1
Power Plant 1 0 1 0 0 0 0 0 0
Water & Wastewater 32 14 28 2 0 0 0 0 21
Stormwater Facilities 9 5 7 0 0 0 0 0 0
Government Facilities 14 2 12 0 0 0 0 0 1
Communication Facilities 80 24 64 9 2 2 2 2 6
Rain Gauges 9 3 7 3 0 0 0 0 1
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Table 7-15
Critical Infrastructure Exposed to Dam Failure Risk in Monterey County Critical Infrastructure
Type
Nacimiento San Antonio Forest Lake
(Scenarios) Los
Padres Dam
Failure
Spillway
Failure
Dam
Failure
Spillway
Failure 1 2 3 4
Hazardous Materials
Active or Idle Oil Well 1,050 811 955 100 0 0 0 0 0
Landfill 0 0 0 0 0 0 0 0 0
Underground Tank 6 1 3 0 0 0 0 0 0
Cal ARP Facility 8 3 7 0 0 0 0 0 1
Transportation
Airport 1 0 0 0 0 0 0 0 0
Bridge 28 21 26 11 0 0 0 0 7
Harbor 1 1 1 1 0 0 0 0 0
Highway (Miles) 96 42 63 8 0 0 0 0 0
Major Road (Miles) 109 38 111 15 0 0 0 0 0.7
Local Road (Miles) 159 57 133 10 3 2 0 4 25
Railroad (Miles) 45 11 46 2 0 0 0 0 0
Levee Failure
A failure of the left bank of the Pajaro levee could threaten critical infrastructure in the town of Pajaro, which includes a middle school, PG&E distribution lines, and industrial sites.
7.4.4 ENVIRONMENT
The environment would be exposed to a number of risks in the event of dam failure or levee failure event. The inundation could introduce many foreign elements into local waterways. This could result in destruction of downstream habitat and could have detrimental effects on many species of animals, especially endangered species such as steelhead.
7.4.5 ECONOMIC IMPACT
Dam and levee failure would likely impact Monterey County’s agricultural economy. When a dam fails or a levee is breached, soil and crop damages in the flooded bottomland areas that impact agricultural management capacities and crop productivity. Breached levees appreciably impact freshwater resources, damage crops and livestock, destroy homes, schools, businesses, and wild species habitat, among other vital, sensitive areas. Levee failure often leads to oil and petroleum contamination of freshwater resources, particularly in dense residential, agricultural, and commercial areas protected by levee systems that depend upon such water resources for drinking, irrigation, and industrial uses.
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7.5 FUTURE TRENDS IN DEVELOPMENT
Most of the areas vulnerable to the more severe impacts from dam and levee failure intersect the mapped flood hazard areas. Flood-related policies in the general plans of participating jurisdictions will help to reduce the risk associated with dam and levee failure for all future development. Flooding due to a dam or levee failure could exceed the special flood hazard areas regulated through local floodplain ordinances, and therefore the County and participating jurisdictions should still consider this hazard when permitting development in mapped dam inundation zones and downstream of high hazard and significant hazard dams. Low hazard dams could become significant or high hazard dams if development occurs below them.
7.6 ISSUES
The most significant issue associated with dam and levee failure involves the properties and populations in the inundation zones. Flooding as a result of a dam or levee failure would significantly impact these areas. There is often limited warning time for dam or levee failures.
These events are frequently associated with other natural hazard events such as earthquakes, landslides, or severe weather, which limits their predictability and compounds the hazard.
Important issues associated with dam and levee failure hazards include the following:
• Dam and levee infrastructure may require repair and improvement to withstand climate change impacts.
• Federally regulated dams have an adequate level of oversight and sophistication in the development of emergency action plans for public notification in the unlikely event of failure. However, the protocol for notification of downstream citizens of imminent failure needs to be tied to local emergency response planning. • Mapping for federally regulated dams is already required and available; however, mapping for nonfederal-regulated dams that estimates inundation depths is needed to better assess the risk associated with dam failure from these facilities. • Most dam failure mapping required at federal levels requires determination of the probable maximum flood. While the probable maximum flood represents a worst-case scenario, it is generally the event with the lowest probability of occurrence. For non- federal-regulated dams, mapping of dam failure scenarios that are less extreme than the probable maximum flood but have a higher probability of occurrence can be valuable to emergency managers and community officials downstream of these facilities. This type of mapping can illustrate areas potentially impacted by more frequent events to support emergency response and preparedness. • The concept of residual risk associated with structural flood control projects should be considered in the design of capital projects and the application of land use regulations. • Addressing security concerns and the need to inform the public of the risk associated with dam failure is a challenge for public officials.
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COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 8-1 DROUGHT
8. DROUGHT
8.1 OVERVIEW
Drought is a significant decrease in water supply relative to what is typical in a given location. It is a normal phase in the climate cycle of most regions, originating from a deficiency of precipitation over an extended period of time, usually a season or more. This leads to a water shortage for some activity, group, or environmental sector. High temperatures, high winds, and low humidity can worsen drought conditions, and can make areas more susceptible to wildfire.
Human demands and actions can also hasten drought-related impacts.
Droughts are frequently classified as one of the four types: meteorological, agricultural, hydrological, or socioeconomic. Meteorological droughts are typically defined by the level of “dryness” when compared to an average, or normal amount of precipitation over a given period of time. Agricultural droughts relate common characteristics of drought to their specific agricultural-related impacts (when the amount of moisture in soil does not meet the needs of a particular crop). Hydrological drought is directly related to the effect of precipitation shortfalls on surface and groundwater supplies. Human factors, particularly changes in land use, can alter the hydrologic characteristics of a basin. Socioeconomic drought is the result of water shortages that affect people and limit the ability to supply water-dependent products in the marketplace.
Droughts cause public health and safety impacts, as well as economic and environmental impacts. Public health and safety impacts are primarily associated with catastrophic wildfire risks and drinking water shortage risks for small water systems in rural areas and private residential wells. Drought impacts are felt first by people most dependent on annual rainfall –
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such as ranchers using dryland range or rural residents relying on wells in low-yield rock formations.
Drought impacts increase with the length of a drought, as carry-over supplies in reservoirs are depleted and water levels in groundwater basins decline. At times, drought may also cause community-wide impacts because of acute water shortages (regulatory use restrictions, drinking water supply, and seawater intrusion). The magnitude of such impact’s correlates directly with local groundwater supplies, reservoir storage, and development densities. Drought conditions can also contribute to or exacerbate extreme heat concerns, particularly with regard to elderly populations.
8.1.1 DROUGHT IN CALIFORNIA
Most of California’s precipitation comes from storms moving across the Pacific Ocean. The path followed by the storms is determined by the position of an atmospheric high-pressure belt that normally shifts southward during the winter, allowing low pressure systems to move into the State. On average, 75% of California’s annual precipitation occurs between November and March, with 50% occurring between December and February. A persistent Pacific high-pressure zone over California in mid-winter signals a tendency for a dry water year.
A typical water year produces about 100 inches of rainfall over the North Coast, 50 inches of precipitation (combination of rain and snow) over the Northern Sierra, 18 inches in the Sacramento area, and 13 inches to 23 inches in the planning area. In extremely dry years, these annual totals can fall to as little as one half, or even one third of these amounts. The Sierra Nevada snowpack serves as the primary agent for replenishing water in the San Francisco Bay area, including Monterey County, and for much of the State of California. A reduction in spring snowpack runoff, whether due to drier winters or to increasing temperatures leading to more rain than snow, can increase risk of summer or fall water shortages throughout the region.
8.1.2 DROUGHT CONDITIONS
The US Drought Monitor (USDM) uses a five-category system to label the severity of droughts.
Drought categories show experts’ assessments of conditions related to dryness and drought including observations of how much water is available in streams, lakes, and soils compared to usual for the same time of year. Drought is classified into five categories:
Since no two states experience the same set of impacts
during a drought. USDM has developed tables of impacts
reported during past droughts in each state for each level of drought on the US Drought Monitor. Impacts by drought
category for California are listed in Table 8-1.
D0 - Abnormally Dry
D1 - Moderate Drought
D2 - Severe Drought
D3 - Extreme Drought
D4 - Exceptional Drought
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Table 8-1: Drought Impacts by USDM Drought Category in California Table 8-1
Drought Impacts by USDM Drought Category in California
D0
Soil is dry; irrigation delivery begins early; Dryland crop germination is stunted Active fire season begins
Winter resort visitation is low; snowpack is minimal
D1
Dryland pasture growth is stunted; producers give supplemental feed to cattle Landscaping and gardens need irrigation earlier; wildlife patterns begin to change Stock ponds and creeks are lower than usual
D2
Grazing land is inadequate; Trees are stressed; plants increase reproductive mechanisms; wildlife diseases increase
Producers increase water efficiency methods and drought-resistant crops Fire season is longer, with high burn intensity, dry fuels, and large fire spatial extent; more fire crews are on staff
Wine country tourism increases; lake- and river-based tourism declines Water temperature increases, programs to divert water to protect fish begin River flows decrease; reservoir levels are low, and banks are exposed D3
Livestock need expensive supplemental feed, cattle and horses are sold; little pasture remains; Orchard removal and well drilling company business increase Fruit trees bud early; producers begin irrigating in the winter Federal water is not adequate to meet irrigation contracts; extracting supplemental groundwater is expensive
Fire season lasts year-round; fires occur in wet parts of state; burn bans implemented Low river levels impede fish migration and cause lower survival rates Wildlife encroaches on developed areas; little native food and water is available for bears, which hibernate less
Water sanitation is a concern, reservoir levels drop significantly, surface water is nearly dry, flows are exceptionally low; water theft occurs Wells and aquifer levels decrease; homeowners drill new wells Water conservation rebate programs increase; water use restrictions are implemented; water transfers increase
Water is inadequate for agriculture, wildlife, and urban needs; reservoirs are extremely low; hydropower is restricted
D4
Fields are left fallow; orchards are removed; vegetable yields are low Fire season is very costly; number of fires and area burned are extensive Fish rescue begins; forest mortality is high; wetlands dry up; survival of native plants and animals is low; wildlife death is widespread; algae blooms appear Policy change, agriculture unemployment is high, food aid is needed Poor air quality affects health, greenhouse gas emissions increase as hydropower production decreases; West Nile Virus outbreaks rise
Water shortages are widespread; surface water is depleted; federal irrigation water deliveries are extremely low; junior water rights are curtailed; water quality is poor Water prices are extremely high; wells are dry, more, and deeper wells are drilled COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 8-4 DROUGHT
8.1.3 LOCAL WATER SUPPLY AND WATER SHORTAGE
Monterey County is isolated from State and Federal water supplies and must rely solely on its local water resources, historically, groundwater and surface water from watersheds with negligible influence from snowpack. The Monterey County Water Resources Agency manages two large reservoirs: San Antonio and Nacimiento. The Monterey Peninsula depends on two water sources: the Carmel River, which drains a 255-square-mile watershed and runs 36 miles from its source in the Santa Lucia mountains to the sea; and the Seaside Basin, which is recharged by local rain, and which underlies the City of Seaside as well as parts of the former Fort Ord and Highway 68 corridor.
Groundwater is the major source of water for many water users in more rural areas of Monterey County with the exception of residents along the Big Sur coast, who depend entirely on surface water and shallow wells for their water supply, and of residents in an area near Greenfield in the Salinas Valley, who have a diversion from the Arroyo Seco River.
High demands on water resources during severe drought can limit water supply. During critically dry years, the California State Water Resources Control Board can mandate water conservation by water users and agencies to address statewide water shortages. Table 8-2 lists State Drought Management Program stages mandated to water right holders.
Table 8-2: State Drought Management Program
Table 8-2
State Drought Management Program
Drought
Stage
State Mandated Customer
Demand Reduction Rate Impacts
Stage 0 or 1 <10% Normal rates
Stage 2 10 to 15% Normal rates; Drought surcharge
Stage 3 15 to 20% Normal rates; Drought surcharge
Stage 4 >20% Normal rates, Drought surcharge
Several efforts are also underway to provide recycled water and reduce the risk seawater intrusion. The Pure Water Monterey Groundwater Replenishment Project (PWM/GWR) replenishes the Seaside Basin with an average of 3500 acre-feet/year of advanced purified recycled water which is injected to the Basin via a series of shallow and deep injection wells.
The recycled water mixes with native groundwater and is stored for later potable water supply.
The Salinas Valley Reclamation Project (SVRP) provides recycled water to growers in the Salinas Valley. The distribution portion of the system, known as the Castroville Seawater Intrusion Project (CISP), delivers water through 45 miles of pipeline to 12,000 acres of farmland in the northern Salinas Valley nearly year-round. While SVRP does not produce potable water, it does help agricultural users in the CSIP area reduce their reliance on the 180- and 400-foot aquifers, which are the source of potable water supply for several communities including Castroville and the City of Salinas.
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8.2 HAZARD PROFILE
8.2.1 HISTORY
The California Department of Water Resources has state hydrologic data back to the early 1900s. The hydrologic data show multi-year droughts from 1912 to 1913, 1918 to 1920, 1922 to 1924, and 1928 to 1934. Since then, a number of prolonged periods of drought occurred in California, all of which impacted Monterey County to some degree. 1976 to 1977 Drought: California had one of its most severe droughts due to lack of rainfall during the winters of 1976 and 1977. 1977 was the driest period on record in California, with the previous winter recorded as the fourth driest in California’s hydrological history. The cumulative impact led to widespread water shortages and severe water conservation measures throughout the state. Only 37% of the average Sacramento Valley runoff was received, with just
6.6 million acre-feet recorded. Over $2.6 billion in crop damage was recorded in 31 counties.
FEMA declared a drought emergency (Declaration 3023-EM) on January 20, 1977, for 58 California counties.
1987 to 1992 Drought: California received precipitation well below average levels for four consecutive years. While the Central Coast was most affected, the Sierra Nevadas in Northern California and the Central Valley counties were also affected. During this drought, only 56% of average runoff for the Sacramento Valley was received, totaling just 10 million acre-feet. In 1991, the State Water Project sharply decreased deliveries to water suppliers. By February 1991, all 58 counties in California were experiencing drought conditions. Urban areas as well as agricultural areas were impacted.
2007 to 2009 Drought: The governor issued an executive order that proclaimed a statewide drought emergency on June 4, 2008, after spring 2008 was the driest spring on record, with low snowmelt runoff. On February 27, 2009, the governor proclaimed a state of emergency for the entire state as severe drought conditions continued. The largest court-ordered water restriction in state history (at the time) was imposed.
2012 to 2016 Drought: The most recent major drought in California set several records for the state and was one of the most severe droughts on record. On January 17, 2014, Governor Jerry Brown declared a statewide drought emergency in response to California’s driest year on record, with nearly 99% of the state considered abnormally dry or worse, and almost two-thirds of the state (including Monterey County) in extreme drought conditions. In the State of Emergency declaration, Governor Brown directed state officials to assist farmers and communities that are economically impacted by dry conditions. The Governor also directed state agencies to use less water and hire more firefighters and initiated a greatly expanded water conservation public awareness campaign. On April 2, 2017, Governor Brown lifted the drought emergency, but declared that California must continue water conservation efforts.
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2021 Drought: On July 8, 2021, Governor Gavin Newsom declared a drought emergency in Monterey County along with 8 other Counties. This declaration was an expansion of the May 10, 2021, drought declaration, with 50 of California's 58 counties now included in the drought emergency declaration. Drought conditions in California as of August 17, 2021, are shown in Figure 8-1.
Figure 8-1
US Drought Monitor, Drought Conditions as of August 17, 2021
Figure 8-1: US Drought Monitor, Drought Conditions as of August 17, 2021 Source: The U.S. Drought Monitor is jointly produced by the National Drought Mitigation Center at the University of Nebraska-Lincoln, the United States Department of Agriculture, and the National Oceanic and Atmospheric Administration. Map courtesy of NDMC.
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The US Department of Agriculture (USDA) declares agriculture-related disasters for losses resulting from drought, flood, fire, freeze, tornadoes, pest infestation, and other natural disasters. Between 2012 and 2021, the period for which data was available, Monterey County was included in 21 USDA disaster declaration in relation to drought, listed in Table 8-3.
Table 8-3: USDA Agricultural Disaster Designations in Monterey County (2012-2021) Table 8-3
USDA Agricultural Disaster Designations in Monterey County (2012-2021) Designation
Number Disaster Type Crop Disaster
Year
S4958 Drought 2021
S4969 Drought 2021
S4916 Drought 2021
S4467 Drought 2019
S4460 Drought 2018
S4144 Drought 2017
S4163 Drought 2017
S3952 Drought, High Winds, Wildfire, Excessive Heat, and Insects 2016 S3784 Drought, High Winds, Wildfire, Excessive Heat, and Insects 2015 S3943 Drought 2015
S3626 Drought, High Winds, Wildfire, Excessive Heat, and Insects 2014 S3637 Drought, High Winds, Wildfire, Excessive Heat, and Insects 2014 S3626 Drought, High Winds, Wildfire, Excessive Heat, and Insects 2014 S3637 Drought, High Winds, Wildfire, Excessive Heat, and Insects 2014 S3743 Drought 2014
S3491 Drought, High Winds, Wildfire, Excessive Heat, and Insects 2013 S3497 Drought, High Winds, Wildfire, Excessive Heat, and Insects 2013 S3504 Drought, High Winds, Wildfire, Excessive Heat, and Insects 2013 S3547 Drought, High Winds, Wildfire, Excessive Heat, and Insects 2013 S3569 Drought, High Winds, Wildfire, Excessive Heat, and Insects 2013 S3268 Drought, High Winds, Wildfire, Excessive Heat, and Insects 2012 S3379 Drought 2012
S3452 Drought 2012
Source: United States Department of Agriculture (USDA), Disaster Designation Information, Last updated August 20, 2021
The National Drought Mitigation Center developed the Drought Impact Reporter in response to the need for a national drought impact database for the US. Information comes from a variety of sources: on-line, drought-related news stories and scientific publications, members of the public, members of the media, and staff of government agencies.
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The Drought Impact Reporter found that Monterey County was affected by 111 impacts from droughts from January 2012 through November 2021 in the following categories (note that some impacts have been assigned to more than one category). 30
8.2.2 LOCATION
Drought is a regional phenomenon with the potential to impact the entire population of Monterey County directly or indirectly, be it from water restrictions, higher water and food prices, reduced air or water quality, or restricted access to recreational areas. No portion of the County is immune from drought conditions. However, the most significant financial losses are likely to occur in areas that are primarily agricultural.
Lack of winter snowfall in the mountains can eventually lead to agricultural impacts due to decreased stream flows. Droughts of just a few weeks during critical periods of plant development can have disastrous effects on agriculture production. Reduced reservoir storage from decreased runoff in the mountains can lead to water shortages. Droughts that occur in populated areas may not have direct effects to the residents but may increase the threat of wildfire in the wildland urban interface areas.
8.2.3 FREQUENCY
Droughts originate from a deficiency of precipitation resulting from an unusual weather pattern. If the weather pattern lasts a short time (a few weeks or a couple of months), the drought is considered short-term. If the weather pattern becomes entrenched and the
30 Drought Impact Reporter, National Drought Mitigation Center 59 Relief, Response & Restrictions Impacts
57 Water Supply & Quality Impacts
35 Agriculture Impacts
31 Society & Public Health Impacts
22 Plants & Wildlife Impacts
19 Fire Impacts
7 Tourism & Recreation Impacts
6 Business & Industry Impacts
5 Energy Impacts
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precipitation deficits last for several months or years, the drought is considered to be long- term. It is possible for a region to experience a long-term circulation pattern that produces drought, and to have short-term changes in this long-term pattern that result in short-term wet spells. Likewise, it is possible for a long-term wet circulation pattern to be interrupted by short- term weather spells that result in short-term drought.
According to historical data prepared by the National Drought Mitigation Center, Monterey County, has experienced some level of drought almost every year during the past 20 years.
Time series data by percentage area in drought conditions in Monterey County from the US Drought Monitor 31 is shown in Figure 8-2. Therefore, droughts likely are likely to occur frequently in Monterey County at varied severities in the future.
Figure 8-2
Monterey County Percentage Area Drought Conditions
Figure 8-2: Monterey County Percentage Area Drought Conditions
8.2.4 SEVERITY
Drought can have a widespread impact on the environment and the economy, although it typically does not result in loss of life or damage to property. The severity of a drought depends on the degree of moisture deficiency, the duration, and the size and location of the affected area. The longer the duration of the drought and the larger the area impacted, the more severe the potential impacts. Unlike most disasters, droughts normally occur slowly but last a long time. Drought can have severe impacts in Monterey County’s water resources, which are already over-stretched by the demands of a growing agriculture economy and population.
The agricultural sector clearly demonstrates the site-specific nature of drought impacts.
Agricultural drought impacts are normally felt earliest by those relying on unmanaged water supplies: entities carrying out dryland grazing and non-irrigated crop production, usually grain crops. Impacts to irrigated agriculture depend on the source and nature of the irrigation water supply, whether it be local groundwater, local surface water, or imported surface water, and
31 Time Series Data, US Drought Monitor
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any water rights or contractual provisions that may be associated with the source. The extent to which producers may mitigate water shortage impacts depends on multiple factors but is heavily influenced by economic considerations. Factors involved in making decisions about mitigating irrigation water shortages include availability and costs of pumping groundwater, price of alternative surface water sources, capital investments associated with maintaining permanent plantings, and status of international crop markets.
Drought generally does not affect groundwater sources as quickly as surface water supplies, but groundwater supplies generally take longer to recover. Reduced precipitation during a drought means that groundwater supplies are not replenished at a normal rate, and in many cases, groundwater is more heavily relied upon during periods of drought due to a reduction in surface water availability. This can lead to a reduction in groundwater levels, decreases in water quality, and problems such as reduced pumping capacity or wells going dry. Long term drought conditions in the County could lead to increased groundwater mining in the Deep Aquifers.
Reduced replenishment of groundwater also affects streams. Much of the flow in streams comes from groundwater, especially during the summer when there is less precipitation and after snowmelt ends. Reduced groundwater levels mean that even less water will enter streams when steam flows are lowest.
8.2.5 WARNING TIME
Droughts are climatic patterns that occur over long periods of time. Only generalized warning can take place due to the numerous variables that scientists have not pieced together well enough to make accurate and precise predictions. Empirical studies conducted over the past century have shown that meteorological drought is never the result of a single cause. It is the result of many causes, often synergistic in nature; these include global weather patterns that produce persistent, upper-level high-pressure systems along the West Coast with warm, dry air resulting in less precipitation.
Scientists currently do not know how to predict drought more than a month in advance for most locations. Predicting drought depends on the ability to forecast precipitation and temperature. Anomalies of precipitation and temperature may last from several months to several decades. How long a drought will last depends on interactions between the atmosphere and the oceans, soil moisture and land surface processes, topography, internal dynamics, and the accumulated influence of weather systems on the global scale.
8.3 SECONDARY HAZARDS
Drought is often accompanied by extreme heat, exposing people to the risk of sunstroke, heat cramps and heat exhaustion. Pets and livestock are also vulnerable to heat-related injuries.
Crops can be vulnerable as well. For more information on heat risk in Monterey County, refer to Severe Weather in Section 14.
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8.3.1 SEAWATER INTRUSION
Droughts can cause and exacerbate seawater intrusion in Monterey Bay area. Drought conditions can lead to increases in groundwater pumping, including potential pumping from deep aquifers, and this loss of groundwater increases seawater intrusion. According to the 2015 Urban Water Management Plan for the Salinas District, the annual non-drought overdraft of the Salinas Valley Groundwater Basin is estimated to be approximately 45,300 AF per year. During droughts, the annual overdraft can escalate to between 150,000 to 300,000 AF per year. As a result of this consistent overdraft, groundwater levels in the Salinas Valley Groundwater Basin have dropped below sea level, allowing seawater to intrude from Monterey Bay into aquifers located 180 and 400 feet below ground surface. While basin overdraft conditions are expected to improve by the year 2030 due to water reclamation efforts, recent groundwater modeling from the Salinas Valley Integrated Ground and Surface Water Model (SVIGSM) predicted seawater intrusion to continue to worsen, though at a decreased rate.
8.3.2 WILDFIRE
A prolonged lack of precipitation dries out vegetation, which becomes increasingly susceptible to wildfire ignition as the duration of the drought extends. For more information on wildfire risk in Monterey County, refer to Wildfire in Section 18.
8.3.3 DEBRIS FLOWS
Post-fire vegetation recovery on burn scars is necessary for winter-storm slope stability.
Drought conditions may slow the vegetation recovery rates on burn scars causing a higher debris flow likelihood for a longer period following a wildfire. For more information on debris flow risk in Monterey County, refer to Slope Failure in Section 15.
8.4 RISK ASSESSMENT
The National Drought Mitigation Center uses three categories to describe likely drought impacts:
• Population/Social Impacts: These impacts affect people’s health and safety. Social impacts include public safety, health, conflicts between people when there is not enough water to go around, and changes in lifestyle.
• Economic Impacts: These impacts of drought cost people (or businesses) money, farmers’ crops are destroyed; low water supply necessitates spending on irrigation or to drill new wells; businesses that sell boats and fishing equipment may not be able to sell their goods.
• Environmental Impacts: Plants and animals depend on water. When a drought occurs, their food supply can shrink, and their habitat can be damaged.
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8.4.1 POPULATION AND SOCIAL IMPACTS
The entire population of Monterey County is vulnerable to drought events. Drought can affect people’s health and safety, including health problems related to low water flows, poor water quality, or dust. Drought also is often accompanied by extreme heat, exposing people to the risk of sunstroke, heat cramps and heat exhaustion. Other possible impacts include recreational risks; effects on air quality; diminished living conditions related to energy, air quality, and hygiene; compromised food and nutrition; and increased incidence of illness and disease.
Water shortages can affect access to safe, affordable water, with substantial impacts on low- income families and communities burdened with environmental pollution. Disadvantaged communities in areas in the Central Coast region, such as the City of Salinas, were highly affected by water shortages during the 2011-2016 drought and another extend period of drought would likely disproportionality affect low-income communities. Drought changes also exacerbated affordability concerns for low-income households
8.4.2 ECONOMIC IMPACT
Drought causes the most significant economic impacts on industries that use water or depend on water for their business, most notably, agriculture and related sectors (forestry, fisheries, and waterborne activities), power plants and oil refineries. In addition to losses in yields in crop and livestock production, drought is associated with increased insect infestations, plant diseases, and wind erosion. Drought can lead to other losses because so many sectors are affected- losses that include reduced income for farmers and reduced business for retailers and others who provide goods and services to farmers. This leads to unemployment, increased credit risk for financial institutions, capital shortfalls, and loss of tax revenue. Prices for food, energy, and other products may also increase as supplies decrease. Although most businesses will still be operational, they may be affected aesthetically—especially the recreation and tourism industry. Moreover, droughts within another area could affect food supply/price of food for residents within the County.
Monterey County’s agricultural sector is particularly vulnerable to drought conditions, with consequences that directly relate to the water available for irrigation purposes. Heat conditions associated with drought exacerbate agricultural irrigation demands when water levels are at their lowest. Reduction in precipitation coupled with heat stress can adversely impact crop production. In the Salinas Valley, agricultural water is made available from groundwater sources that are recharged by the Salinas River, which relies on water releases from the Nacimiento, and San Antonio reservoirs as controlled by MCWRA. Since 1990, growers in the Castroville Seawater Intrusion Project (CSIP) distribution system area have utilized tertiary-treated recycled water produced by M1W in partnership with MCWRA to irrigate their crops. In 2006, M1W and MCWRA added the Salinas River Diversion Facility (SRDF), which supplies recycled water to 12,000 acres of productive farmland. The SRDF relies upon water from the upstream Reservoirs to operate, providing Salinas River flows to supplement recycled water and further COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 8-13 DROUGHT
reduce groundwater pumping in the 180- and 400-foot aquifers of the Salinas Valley Groundwater Basin. During years when the SRDF is non-operational due to drought, a corresponding increase in groundwater pumping in CSIP region has been observed.
8.4.3 ENVIRONMENTAL IMPACT
Environmental losses from drought are associated with damage to plants, animals, wildlife habitat, and air and water quality; forest and range fires; degradation of landscape quality; loss of biodiversity; and soil erosion. Some of the effects are short-term and conditions quickly return to normal following the end of the drought. Other environmental effects linger for some time or may even become permanent. Wildlife habitat, for example, may be degraded through the loss of wetlands, lakes, and vegetation. However, many species will eventually recover from this temporary aberration. The degradation of landscape quality, including increased soil erosion, may lead to a more permanent loss of biological productivity. Although environmental losses are difficult to quantify, growing public awareness and concern for environmental quality has forced public officials to focus greater attention and resources on these effects.
8.5 FUTURE TRENDS IN DEVELOPMENT
Land use planning is directed by general plans adopted under California’s General Planning Law.
Municipal planning partners are encouraged to establish general plans with policies to deal with issues of water supply and protection of water resources. These plans increase capability at the local municipal level to protect future development from impacts of drought. All planning partners reviewed their general plans under the capability assessments undertaken for this hazard mitigation plan. Deficiencies revealed by these reviews are identified as mitigation actions to increase capability to deal with future trends in development.
8.6 ISSUES
• The probability of increased drought frequencies and durations due to climate change. • The promotion of active water conservation even during non-drought periods. • Application of alternative techniques (groundwater recharge, continued/expanded water reclamation, local capture and reuse, desalination, and transfer) to stabilize and offset water supply shortfalls.
• Regular occurrence of drought or multiyear droughts that may limit the County’s ability to successfully recover from or prepare for more occurrences. • The impact of prolonged drought conditions on Monterey County’s agricultural industry, a key economic driver in the County.
• Severe drought could have serious impacts on water quality. • Increased groundwater pumping during drought years exacerbating seawater intrusion. • A severe drought would result in drier fuels which could create increased wildfire risk.
Lack of water due to drought could also impede firefighting capabilities.
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9. EARTHQUAKE
9.1 OVERVIEW
An earthquake is a sudden motion or trembling caused by an abrupt shift of rock along a fracture in the earth or a contact zone between tectonic plates. Most destructive quakes are caused by dislocations of the crust. The crust may first bend and then, when the stress exceeds the strength of the rocks, break, and snap to a new position. In the process of breaking, vibrations called “seismic waves” are generated. These waves travel outward from the source of the earthquake at varying speeds. Earthquakes usually occur without warning and, after just a few seconds, can cause massive structural damage, injury, and loss of life, as well as damage to infrastructure networks, such as water, power, gas, communication, and transportation. The effects of an earthquake can be felt far beyond the site of its occurrence. The degree of damage depends on many interrelated factors. Among these are: the magnitude, focal depth, distance from the causative fault, source mechanism, duration of shaking, high rock accelerations, type of surface deposits or bedrock, degree of consolidation of surface deposits, presence of high groundwater, topography, and the design, type, and quality of building construction.
9.1.1 EARTHQUAKE GEOLOGY
The Earth’s crust, which is the rigid outermost shell of the planet, is broken into seven or eight major tectonic plates and many minor plates. Where the plates meet, they move in one of three ways: convergent (two plates moving together), divergent (two plates moving apart), or transform (two plates moving parallel to one another). Earthquakes, volcanic activity, mountain building, and oceanic trench formation occur along plate boundaries.
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Subduction is a geological process that takes place at convergent boundaries of tectonic plate, in which one plate moves under another. Regions where this process occurs are known as subduction zones, and they have the potential to generate highly damaging earthquakes. The transform (parallel) movement of tectonic plates against one another creates stresses that build as the rocks are gradually deformed. The rock deformation, or strain, is stored in the rocks as elastic strain energy. When the strength of the rock is exceeded, rupture occurs along a fault.
The rocks on opposite sides of the fault slide past each other as they spring back into a more relaxed position. The strain energy is released partly as heat and partly as elastic waves called seismic waves. The passage of seismic waves produces the ground shaking in earthquakes.
Monterey County lies within the California Coast Ranges, a region dominated by active tectonic movement of the North American Plate, east of the San Andreas Fault, and the Pacific Plate to the west. Regional tectonic forces generate an estimated relative motion between the North American and Pacific plates of approximately 2 inches per year. Over time, these forces have created the varied mountainous, valley, and fault-bound blocks seen in the County today.
Geologists have found that earthquakes tend to reoccur along faults, which are zones of weakness in the earth’s crust. Even if a fault zone has recently experienced an earthquake, there is no guarantee that all stress has been relieved. Another earthquake could still occur. In fact, relieving stress along one part of a fault may increase it in another part. Therefore, faults are mapped to determine earthquake hazards. In California, a system has been developed by the California Geological Survey (CGS) and US Geological Survey (USGS) to assess the activity of faults. CGS categorizes faults based on the age of last displacement, as defined below:
• Historic faults have ruptured during historic time (approximately the last 200 years) and are associated with either a recorded earthquake with surface rupture, measurable surface displacement along a fault in the absence of notable earthquakes (e.g., aseismic creep), or displaced survey lines.
• Holocene age faults have ruptured within the past 11,000 years, as demonstrated by geomorphic or stratigraphic evidence of displacement of Holocene deposits or geomorphic features.
• Late Quaternary age faults have ruptured within approximately the last 700,000 years, as demonstrated by geologic and geomorphic evidence of displacement of Late Quaternary deposits or geomorphic features. This category may include younger faults that lack deposits by which to differentiate younger displacements. • Quaternary age faults show evidence of surface rupture younger than approximately 1.6 million years ago.
• Pre-Quaternary age faults lack recognized evidence of Quaternary displacement or show evidence of no displacement during Quaternary time. Also included in this category are known faults for which detailed studies have not determined fault activity, and those faults identified only in preliminary mapping.
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The classification of “active” is applied to historic and Holocene age faults; “potentially active” is applied to Quaternary and late Quaternary age faults; and “inactive” is applied to pre- Quaternary age faults. These classifications are not meant to imply that inactive faults will not rupture, only that they have not been shown to have ruptured for some time and the probability of fault rupture is low. Known faults in the County by age are shown in Figure 9-1.
Figure 9-1
Known Faults in Monterey County by Age
Figure 9-1: Known Faults in Monterey County by Age
9.1.2 EARTHQUAKE CLASSIFICATIONS
Earthquakes are typically classified in one of two ways: By the amount of energy released, measured as magnitude; or by the impact on people and structures, measured as intensity.
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Magnitude
The most common method for measuring earthquakes is magnitude, which measures the strength of earthquakes. An earthquake’s magnitude is a measure of the energy released at the source of the earthquake and is related to the total area of the fault that ruptured, the amount of displacement across the fault, and the actual location of the energy release inside the earth.
The Richter scale measures magnitude of earthquakes based on the amplitude of the largest energy wave released by the earthquake. Richter scale readings are suitable for smaller earthquakes; however, because it is a logarithmic scale, the scale does not clearly distinguish the magnitude of large earthquakes above a certain level.
Therefore, while the Richter scale is the most well-known measurement for earthquake magnitude, the majority of scientists currently use the Moment Magnitude (Mw) Scale to measure magnitude. As shown in Table 9-1, there are seven earthquake magnitude classes, ranging from great to micro. A magnitude class of great can cause tremendous damage to infrastructure, compared to a micro class, which results in minor damage to infrastructure.
Table 9-1: Earthquake Magnitude Classes (Moment Magnitude Scale) Table 9-1
Earthquake Magnitude Classes (Moment Magnitude Scale)
Magnitude Class Magnitude Range Description
Great Magnitude > 8 Tremendous Damage
Major 7 ≤ Magnitude < 7.9 Widespread Heavy Damage
Strong 6 ≤ Magnitude < 6.9 Severe Damage
Moderate 5 ≤ Magnitude < 5.9 Considerable Damage
Light 4 ≤ Magnitude < 4.9 Moderate Damage
Minor 3 ≤ Magnitude < 3.9 Rarely Causes Damage
Micro Magnitude < 3 Minor Damage
Intensity
Although an earthquake has only one magnitude, it can have many intensities. The effects of an earthquake in a particular location are measured by intensity. Intensity at a given site is a function of earthquake magnitude, increasing as magnitude increases; distance from the causative fault, decreasing as distance increases; and underlying site geology, generally increasing in areas with weak, unconsolidated materials. Earthquake intensity decreases with increasing distance from the epicenter of the earthquake.
The Modified Mercalli Intensity value assigned to a specific site after an earthquake is a more meaningful measure of severity to the nonscientist than magnitude because intensity refers to the effects experienced at that place. The lower numbers on the intensity scale generally deal with the how the earthquake is felt by people, while the higher numbers are based on observed structural damage.
Table 9-2 provides an overview of the Modified Mercalli Intensity scale.
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Table 9-2: Modified Mercalli Intensity Level Descriptions Table 9-2
Modified Mercalli Intensity Level Descriptions
Intensity Shaking Description/ Damage
I Not Felt Not felt except by a very few under especially favorable conditions.
II Weak Felt by only a few persons at rest, especially on upper floors of building. Delicately suspended objects may swing.
III Weak
Felt quite noticeably by persons indoors, especially on upper floors of buildings. Many people do not recognize it as an earthquake.
Standing motor cars may rock slightly. Vibrations similar to the passing of a truck. Duration estimated.
IV Light
Felt indoors by many, outdoors by few during the day. At night, some awakened. Dishes, windows, doors disturbed; walls make cracking sound. Sensation like heavy truck striking building. Standing motor cars rocked noticeably.
V Moderate
Felt by nearly everyone; many awakened. Some dishes, windows broken. Unstable objects overturned. Pendulum clocks may stop.
Disturbances of trees, poles, and other tall objects sometimes noticed.
VI Strong
Felt by all, many frightened. Many objects fall from shelves. Some heavy furniture moved; a few instances of fallen plaster, broken windows, and damaged chimneys. Damage slight. Some fall of tree limbs, isolated rockfalls and landslides, and isolated liquefaction.
VII Very
Strong
Damage negligible in buildings of good design and construction; slight to moderate in well-built ordinary structures; considerable damage in poorly built or badly designed structures; some chimneys broken. Tree damage, rockfalls, landslides, and liquefaction are more severe and widespread with increasing intensity.
VIII Severe
Many find it difficult to stand. Damage slight in specially designed structures; considerable in ordinary substantial buildings with partial collapse; great in poorly built structures. Panel walls thrown out of frame structures. Fall of chimneys, factory stacks, columns, monument walls, and heavy furniture overturned. Sand and mud ejected in small amounts. Changes in well water. Persons driving in cars disturbed.
IX Violent
Some forcibly thrown to the ground. Damage considerable in specially designed structures; well-designed frame structures thrown out of plumb. Damage great in substantial buildings, with partial collapse. Buildings shifted off foundations. Ground cracked conspicuously. Underground pipes broken.
X Extreme
Some well-built structures destroyed; most masonry and frame structures destroyed with foundations; ground badly cracked.
Railway lines bent. Landslides considerable from riverbanks and steep slopes. Shifted sand and mud.
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9.1.3 GROUND MOTION
Earthquake hazard assessment is also based on expected ground motion. The ground experiences acceleration as it shakes during an earthquake. The peak ground acceleration (PGA) is the largest acceleration recorded by a monitoring station during an earthquake. PGA is a measure of how hard the earth shakes in a given geographic area and is expressed as a percentage of the acceleration due to gravity. Horizontal and vertical PGA varies with soil or rock type. Instruments called accelerographs record levels of ground motion due to earthquakes at stations throughout a region. These readings are recorded by state and federal agencies that monitor and predict seismic activity. Earthquake hazard assessment involves estimating the annual probability that certain ground motion accelerations will be exceeded, and then summing the annual probabilities over a time period of interest.
Maps of earthquake shaking hazards provide information for creating and updating seismic design requirements for building codes, insurance rate structures, earthquake loss studies, retrofit priorities and land use planning. After thorough review of the studies, professional organizations of engineers update the seismic-risk maps and seismic design requirements contained in building codes.
Building codes that include seismic provisions specify the horizontal force due to lateral acceleration that a building should be able to withstand during an earthquake. Buildings, bridges, highways, and utilities built to meet modern seismic design requirements are typically able to withstand earthquakes better, with less damage and disruption. PGA values are directly related to these lateral forces that could damage “short period structures” such as single-family dwellings. Longer-period response components determine the lateral forces that damage larger structures with longer natural periods such as apartment buildings, factories, high-rises, and bridges. Table 9-3 lists damage potential and perceived shaking by PGA factors, compared to the Mercalli scale.
Table 9-3: Modified Mercalli Scale and Peak Ground Acceleration Table 9-3
Modified Mercalli Scale and Peak Ground Acceleration
Modified
Mercalli Scale
Perceived
Shaking
Potential Structural Damage Estimated PGA
(%g) Resistant Buildings Vulnerable Buildings
I Not Felt None None < 0.17%
II-III Weak None None 0.17% - 1.4%
IV Light None None 1.4% - 3.9%
V Moderate Very Light Light 3.9% - 9.2%
VI Strong Light Moderate 9.2% - 18%
VII Very Strong Moderate Moderate/Heavy 18% - 34%
VIII Severe Moderate/Heavy Heavy 34% - 65%
IX Violent Heavy Very Heavy 65% - 124%
X - XII Extreme Very Heavy Very Heavy > 124%
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9.1.4 LIQUEFACTION
The impact of an earthquake on structures is a function of ground shaking, distance from the source of the quake, and liquefaction, an effect of an earthquake in which soils lose their shear strength and behave as liquid, damaging structures that derive their support from the soil.
Liquefaction involves loose sandy soil with a high-water content that undermines the ground’s ability to solidly support building structures during an earthquake. Liquefaction occurs when ground shaking causes the mechanical properties of some fine grained, saturated soils to liquefy and act as a fluid (liquefaction). It is the result of a sudden loss of soil strength due to a rapid increase in soil pore water pressures caused by ground shaking. In order for liquefaction to occur, three general geotechnical characteristics should be present:
• Ground water should be present within the potentially liquefiable zone • The potentially liquefiable zone should be granular and meet a specific range in grain- size distribution
• The potentially liquefiable zone should be of low relative density. If those criteria are present and strong ground motion occurs, then those soils could liquefy, depending upon the intensity and duration of the strong ground motion.
Liquefaction that produces surface effects generally occurs in the upper 40 to 50 feet of the soil column, although the phenomenon can occur deeper than 100 feet. The duration of ground shaking is also an important factor in causing liquefaction to occur. The larger the earthquake magnitude, and the longer the duration of strong ground shaking, the greater the potential there is for liquefaction to occur.
A program called the National Earthquake Hazard Reduction Program (NEHRP) creates maps based on soil characteristics to help identify locations subject to liquefaction. Table 9-4 summarizes NEHRP soil classifications. NEHRP Soils B and C typically can sustain ground shaking without much effect, dependent on the earthquake magnitude. The areas that are commonly most affected by ground shaking have NEHRP Soils D, E and F. In general, these areas are also most susceptible to liquefaction.
Table 9-4: NEHRP Soil Classification System
Table 9-4
NEHRP Soil Classification System
NEHRP
Soil Type Description Mean Shear Velocity
to 30 m (m/s)
A Hard Rock 1,500
B Firm to Hard Rock 760-1,500
C Dense Soil/ Soft Rock 360-760
D Stiff Soil 180-360
E Soft Clays <180
F Special Study Soils- liquefiable soils, sensitive clays, organic soils, soft clays >36 m thick
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9.2 HAZARD PROFILE
9.2.1 HISTORY
Earthquakes tend to reoccur where they have struck before. The central California coast has a history of damaging earthquakes, primarily associated with the San Andreas fault, which runs through the southeastern portion of the County for about 30 miles. There have also been a number of 5.0 to 6.5 earthquakes on other faults which have affected large portions of the region. The County has experienced 429 earthquakes since 1900 and 67 earthquakes since 2000 of 4.0 magnitude or higher. Table 9-5 summarizes the year, epicenter, and magnitude of major earthquakes (6.0 magnitude or more) that have affected the County since 1850.
Table 9-5: Monterey County Earthquakes, Magnitude 6.0+ (1838- Present) Table 9-5
Monterey County Earthquakes, Magnitude 6.0+ (1838-Present) Date Magnitude Location
2004 6.0 Parkfield
2003 6.5 San Simenon
1989 6.9 Loma Prieta
1984 6.1 Morgan Hill
1983 6.5 Coalinga
1952 6.2 Monterey Bay
1966 6.6 Parkfield
1934 6.0 Parkfield
1926 6.3 Monterey Bay
1922 6.5 Parkfield
1906 7.8 San Francisco
1901 6.4 Parkfield
1857 7.9 Parkfield
The approximate 7.9 Fort Tejon earthquake of 1857 was one of the largest earthquakes ever recorded in the US and the largest in California history. It originated in Parkfield in Monterey County and caused a surface rupture scar of about 225 miles in length along the San Andreas Fault to the Cajon Pass northwest of San Bernardino. Yet, despite the immense scale of this quake, only two people were reported killed by the effects of the shock. The fact that only two lives were lost was primarily due to the fact that in 1857 California was sparsely populated, especially in the regions of strongest shaking. Were the Fort Tejon shock to happen today, the damage would easily run into the billions of dollars, and the loss of life would likely be substantial.
In 1906, the 7.8. magnitude San Francisco Earthquake caused severe damage. The Salinas River bottom lands were severely ruptured, fissured, and otherwise deformed. The Spreckels Sugar Mill, situated on the banks of the river, suffered more severely probably than any other steel COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 9-9 EARTHQUAKE
structure in the State. Other damage from the 1906 earthquake included destruction of the wharf at Moss Landing and destruction of the Hotel Del Monte in Monterey.
On October 17, 1989, the Loma Prieta earthquake occurred in neighboring Santa Cruz County.
The earthquake lasted only 10 to 15 seconds but was a 6.9 magnitude. In Moss Landing, liquefaction destroyed a causeway, damaged the bridge linking the Moss Landing spit to the mainland and cracked the paved road on Paul's Island. 32 A section of Highway 1 through Monterey, a bridge carrying Highway 1 over the Salinas River, and the Salinas River rail bridge suffered damage. In the Old Town Salinas historical district, unreinforced masonry buildings were partially destroyed. The 2004 6.0 magnitude Parkfield earthquake caused only minor damage but was long-anticipated event on the San Andreas fault and is the world’s best recorded earthquake to date.
9.2.2 LOCATION
Monterey County is located in a region of high seismicity with numerous local faults, as shown below. The primary seismic hazard for the County is potential ground shaking from these faults.
Major faults in Monterey County are described below and mapped by slip rate in Figure 9-2.
San Andreas Fault
The San Andreas Fault runs through the southeastern portion of the County for approximately 30 miles and poses the single greatest seismic hazard to the County. To the north and south of the County, the fault appears to be currently locked with no detectable movement. Between these locked sections, within the County, the San Andreas Fault creeps (slips aseismically).
From San Juan Bautista to Parkfield, the creeping section produces numerous small to moderate (mostly magnitude 6.0 and smaller) earthquakes but no large ones. The stretch of the fault between Parkfield and Gold Hill defines a transition zone between the creeping and locked behavior of the fault. The slip rate of the San Andreas fault is Greater than 5.0 mm/year.
Palo Colorado-San Gregorio Fault
The Palo Colorado-San Gregorio Fault zone connects the Palo Colorado Fault near Point Sur, south of Monterey, with the San Gregorio Fault near Point Ano Nuevo in Santa Cruz County. It is a right-lateral strike-slip fault zone oriented generally north-south consisting of two or more parallel and fairly continuous fault segments that extend at least 60 miles. The slip rate of the San Gregorio–Palo Colorado fault is between 1.0 and 5.0 mm/year.
Monterey Bay-Tularcitos Fault
The Monterey Bay-Tularcitos Fault zone lies seaward of the city of Seaside, extending northwesterly to the Pacific Ocean. It is composed of short, discontinuous parallel fault segments ranging from 3 to 9 miles in length.
32 USGS
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The Monterey Bay Fault–Tularcitos zone is either truncated or merges with the San Gregorio fault segment of the Palo Colorado–San Gregorio Fault zone. The slip rate of the Monterey Bay- Tularcitos fault is between 0.2 and 1.0 mm/year.
Figure 9-2
Known Faults in Monterey County by Slip Rate
Figure 9-2: Known Faults in Monterey County by Slip Rate NEHRP Soil Maps
NEHRP soil types define the locations that will be significantly impacted by an earthquake.
Table 9-4 summarizes NEHRP soil classifications. NEHRP Soils B and C typically can sustain low- magnitude ground shaking without much effect. The areas that are most commonly affected by ground shaking have NEHRP Soils D, E and F.
As shown in Figure 9-3, based on soil type, the location of the most extreme earthquake damage in Monterey County would likely be in some areas of the Monterey Peninsula, areas along the Monterey Bay, and in the Salinas Valley. These areas generally include the largest population centers in the County, and therefore are areas of high concern for earthquake risk reduction.
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Figure 9-3
NEHRP Soil Classes in Monterey County
Figure 9-3: NEHRP Soil Classes in Monterey County
9.2.3 FREQUENCY
California experiences hundreds of earthquakes each year, most with minimal damage and magnitudes below 3.0 on the Richter Scale. Earthquakes that cause moderate damage to structures occur several times a year. According to the California State Hazard Mitigation Plan, earthquakes large enough to cause moderate damage to structures—those of Magnitude 5.5 or larger—occur three to four times a year statewide. Strong earthquakes of Magnitude 6 to 6.9 strike on an average of once every two to three years. Major earthquakes of Magnitude 7 to 7.9 occur in California about once every 10 years. According to the USGS, in the next 30 years, California has a 99.7% chance of a magnitude 6.7 or larger earthquake Geologic studies show that over the past 1,400 to 1,500 years large earthquakes have occurred at about 150-year intervals on the southern segment of the San Andreas Fault (south of Parkfield). As the last large earthquake on the southern San Andreas Fault segment occurred in 1857, that section of the fault is considered a likely location for an earthquake within the next few decades. The northern segment of the fault (north of San Juan Baustista) has a slightly
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lower potential for a great earthquake, as only about 100 years have passed since the 1906 earthquake. The USGS estimates there is a 72% probability (or likelihood) of at least one earthquake of magnitude 6.7 or greater striking somewhere in the greater San Francisco Bay region before 2043. 33 The 30-year probability of an M ≥ 6.7 earthquake on the northern segment of the San Andreas Fault is 21%.
The San Gregorio–Palo Colorado Fault zone has a 10% probability of a magnitude 6.7 or greater earthquake by 2032. The Calaveras-Paicines Fault, which does not run directly through Monterey County, could also be the location of a major earthquake, which would affect the County. The probability of experiencing a Magnitude 6.7 or greater earthquake along the Calaveras Fault in the next 30 years is 26%.
However, as noted above, Monterey County experiences several small detectable earthquakes every year. Also, moderate-sized, potentially damaging earthquakes could occur in this area at any time.
9.2.4 SEVERITY
The severity of an earthquake can be expressed in terms of intensity or magnitude. Intensity represents the observed effects of ground shaking at any specified location. The intensity of earthquake shaking lessens with distance from the earthquake epicenter. Magnitude represents the amount of seismic energy released at the hypocenter of the earthquake. It is based on the amplitude of the earthquake waves recorded on instrument.
The impact of an earthquake is largely a function of the following components:
• Ground shaking (ground motion accelerations)
• Liquefaction (soil instability)
• Distance from the source (both horizontally and vertically) USGS ground motion maps, based on current information about fault zones, show the PGA that has a certain probability of being exceeded in a 50-year period. Mapping of ground shaking potential was used to assess the risk of earthquakes. the hazard from ground shaking is most severe in areas near the San Andreas Fault and in the unconsolidated alluvial areas of the County such as the Salinas and Carmel Valleys.
Earthquake shaking potential in Monterey County is shown in Figure 9-4.
33 USGS, Earthquake Outlook for the San Francisco Bay Region 2014–2043 COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 9-13 EARTHQUAKE
Figure 9-4: Earthquake Shaking Potential
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Liquefaction Susceptibility
Soil liquefaction maps are also useful tools to assess potential damage from earthquakes. When the ground liquefies, sandy or silty materials saturated with water behave like a liquid, causing pipes to leak, roads and airport runways to buckle, and building foundations to be damaged.
Areas in Monterey County most susceptible to liquefaction include the Salinas River and floodplain, the Moss Landing and Elkhorn Slough areas, the Carmel River and floodplain, the San Antonio and Lockwood Valleys, and the Peachtree and Cholame Valleys.
Liquefaction susceptibility in Monterey County is shown in Figure 9-5.
Figure 9-5
Liquefaction Susceptibility in Monterey County
Figure 9-5: Liquefaction Susceptibility in Monterey County
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9.2.5 WARNING TIME
There is no current reliable way to predict the day or month that an earthquake will occur at any given location. Research is being done with warning systems that use the low energy waves that precede major earthquakes. These potential warning systems give approximately 40 seconds notice that a major earthquake is about to occur. The warning time is very short, but it could allow for someone to get under a desk, step away from a hazardous material they are working with, or shut down a computer system.
In 2019, the USGS released ShakeAlert, an earthquake early warning (EEW) system that detects significant earthquakes quickly so that alerts can reach many people before shaking arrives.
ShakeAlert is not earthquake prediction, rather a ShakeAlert Message indicates that an earthquake has begun, and shaking is imminent. The USGS has estimated the warning time would range from seconds to tens of seconds. ShakeAlert can give enough time to take preventative actions before the shaking starts to reduce damage and casualties during an earthquake. Figure 9-6 provides more information on how the ShakeAlert system works.
Figure 9-6
ShakeAlert Earthquake Early Warning Basics
Figure 9-6: ShakeAlert Earthquake Early Warning Basics
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9.3 SECONDARY HAZARDS
Earthquakes can cause collateral emergencies including dam and levee failures, seiches, hazmat incidents, urban conflagration, avalanches, and landslides. In addition to ground motion, several secondary natural hazards can occur from earthquakes. Additionally, urban conflagration can result from gas lines or power lines that are broken or downed during the earthquake. It may be difficult to control a fire, particularly if the water lines feeding fire hydrants are also broken.
9.3.1 DAM AND LEVEE FAILURE
Earthen dams and levees are highly susceptible to seismic events, and the impacts of their eventual failures can be considered secondary risk exposure to earthquakes.
For more information on dam and levee failure risk in Monterey County, refer to Section 7, Dam and Levee Failure.
9.3.2 LANDSLIDES
Earthquakes can cause disastrous landslides. Landslides occur because of horizontal seismic inertia forces induced in the slopes by the ground shaking. The most common earthquake- induced landslides include shallow, disrupted landslides such as rock falls, rockslides, and soil slides. Debris flows are created when surface soil on steep slopes becomes totally saturated with water. Once the soil liquefies, it loses the ability to hold together and can flow downhill at extremely high speeds, taking vegetation and/or structures with it. Slide risks increase after an earthquake during a wet winter.
For more information on landslide risk in Monterey County, refer to Section 15, Slope Failure.
9.3.3 TSUNAMIS
Depending on the location, earthquakes can trigger tsunamis. Tsunamis significantly damage many locations beyond what the earthquake struck; however, coastal communities near the earthquake epicenter that are also vulnerable to tsunamis could experience devastating impacts. As an Oceanic Plate is subducted beneath a Continental Plate, it sometimes brings down the lip of the Continental Plate with it. Eventually, too much stress is put on the lip, and it snaps back, sending shockwaves through the earth’s crust, causing a tremor under the sea, known as an Undersea Earthquake. Factors that affect tsunami generation from an earthquake event include magnitude (generally, a 7.5 magnitude and above), depth of event (a shallow marine event that displaces seafloor), and type of earthquake (thrust as opposed to strike-slip).
For more information on tsunami risk in Monterey County, refer to Section 16, Tsunami.
9.4 RISK ASSESSMENT
9.4.1 POPULATION
According to the FEMA National Risk Index, 415,057 people, or the entire population is exposed to earthquake risk. Whether directly impacted or indirectly impact, the entire population will COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 9-17 EARTHQUAKE
have to deal with the consequences of earthquakes to some degree. Business interruption could keep people from working, road closures could isolate populations, and loss of functions of utilities could impact populations that suffered no direct damage from an event itself.
As seen in Table 9-6, close to 200,000 people, almost half of the population of Monterey County, live in areas with high or moderate liquefaction susceptibility.
Table 9-6: Population Exposed to Areas Susceptible to Liquefaction Table 9-6
Population Exposed to Areas Susceptible to Liquefaction in Monterey County Supervisorial District High Moderate
District 1 23,680 3,256
District 2 45,825 9,223
District 3 14,729 24,549
District 4 7,622 19,936
District 5 35,764 14,625
Total 127,620 71,589
Residents in high-risk areas are more vulnerable to the impact of earthquakes. The degree of vulnerability is dependent on many factors, including the age and construction type of the structures people live in, the soil their homes are constructed on, and their proximity to the fault location, etc.
Two groups are particularly vulnerable to earthquake hazards: the population below the poverty level and those with access and functional needs. Those below the poverty level may lack the financial resources to improve their homes to prevent or mitigate earthquake damage.
Economically disadvantaged residents are also less likely to have insurance to compensate for losses in earthquakes. Those with access and functional needs are vulnerable because they are more likely to need special medical attention, which may not be available due to isolation caused by earthquakes. Some residents may also have more difficulty leaving their homes during earthquake events and could be stranded in dangerous situations.
9.4.2 PROPERTY
All structures in the County are susceptible to earthquake impacts to varying degrees. The most common type of damage from ground shaking is structural damage to buildings, which can range from cosmetic stucco cracks to total collapse. The overall level of structural damage from a nearby large earthquake would likely be moderate to heavy, depending on the characteristics of the earthquake, the type of ground, and the condition of the building. Besides damage to buildings, strong ground shaking can cause severe damage by falling objects such as bookcases or water heaters, or broken water or gas pipes. Fire and explosions resulting from ruptured gas pipes are also major hazards associated with strong ground shaking.
According to Monterey County Assessor records, there are 128,966 residential and non- residential buildings in the County, with a total value of $73,489,253,104. Since all structures in COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 9-18 EARTHQUAKE
the County are susceptible to earthquake impacts to varying degrees, this represents the property exposure to seismic events.
Assessor’s data value total includes land value. Since following an earthquake, the land is likely to still have value even if the structure is destroyed, the exposed value is likely an overestimate.
Therefore, FEMA data was also included in this analysis in addition to the Assessor’s data.
According to the FEMA National Risk Index, in Monterey County, $41,169,506,000 in total building value is exposed to earthquake risk.
A large amount of property in the County is also exposed to liquefaction risk., As seen in Table 9-7, close to 20,000 residential properties, about $12 billion in property value is in areas with high or moderate liquefaction susceptibility. As seen in Table 9-8, close to 22,000 non- residential properties, about $11 billion in property value is in areas with high or moderate liquefaction susceptibility.
Table 9-7: Residential Property Exposed to Areas Susceptible to Liquefaction Table 9-7
Residential Property Exposed to Areas Susceptible to Liquefaction in Monterey County Supervisorial
District
High Moderate
# Value # Value
District 1 673 $372,310,680 253 $133,011,281
District 2 3,547 $1,591,632,718 472 $282,454,095
District 3 1,838 $621,850,036 3,287 $948,153,442
District 4 837 $398,868,120 4,514 $1,933,056,731
District 5 3,729 $3,772,532,646 2,268 $1,882,248,356
Total 10,624 $6,757,194,200 10,794 $5,178,923,905
Table 9-8: Non-Residential Property Exposed to Areas Susceptible to Liquefaction Table 9-8
Non-Residential Property Exposed to Areas Susceptible to Liquefaction in Monterey County Supervisorial
District
High Moderate
# Value # Value
District 1 1,270 $827,677,352 922 $421,513,584
District 2 4,000 $1,109,321,385 1,638 $397,837,469
District 3 3,041 $1,851,569,790 3,273 $2,914,179,282
District 4 745 $744,052,338 2,608 $1,124,210,594
District 5 3,013 $1,754,854,558 1,147 $539,666,562
Total 12,069 $6,287,475,423 9,588 $5,397,407,491
Poorly constructed buildings and manufactured housing units are more vulnerable to structural failure during an earthquake, as well as secondary hazards such as utility disruption and urban conflagration. Older buildings are also more vulnerable to structural failure, as they may have been built before building and seismic code requirements that directly affect the structural integrity of development.
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Of particular concern in Monterey County is unreinforced masonry buildings, which are constructed from materials such as adobe, brick, hollow clay tiles, or other masonry materials and do not contain an internal reinforcing structure, such as rebar in concrete or steel bracing for brick. Unreinforced masonry poses a significant danger during an earthquake because the mortar holding masonry together is typically not strong enough to withstand significant earthquakes. The brittle composition of these buildings can break apart and fall away or buckle, potentially causing a complete collapse of the building.
9.4.3 CRITICAL FACILITIES AND INFRASTRUCTURE
All critical facilities in the County are exposed to the earthquake hazard. Earthquakes pose numerous risks to critical facilities and infrastructure. Hazardous materials releases can occur during an earthquake from fixed facilities or transportation-related incidents. Facilities holding hazardous materials are of particular concern because of possible isolation of neighborhoods surrounding them. During an earthquake, structures storing these materials could rupture and leak into the surrounding area or an adjacent waterway, having a disastrous effect on the environment. Depending on the year of build and construction of each facility containing hazardous materials, the earthquake-initiated hazardous material release potential will vary.
Hazardous materials contained within masonry or concrete structures built before certain benchmark years may be particularly vulnerable.
Transportation corridors can be disrupted during an earthquake, leading to the release of materials to the surrounding environment. Linear utilities and transportation routes are vulnerable to rupture and damage during and after a significant earthquake event. The cascading impact of a single failure can have affects across multiple systems and utility sectors.
Degrading infrastructure systems and future large earthquakes with epicenters near critical regional infrastructure could result in system outages that last weeks for the most reliable systems, and multiple months for others.
Telecommunication systems can be affected by system failure, overloads, loss of electrical power and possible failure of some alternate power systems. Immediately following an event, numerous failures will occur, compounded by system use overload.
Large ground motions resulting from liquefaction, especially lateral spreading, can cause damage to buried pipelines. Most pipe breaks during the Loma Prieta earthquake were in areas with significant liquefiable soil. Broken pipelines represent a serious public safety issue as demonstrated by burning natural gas lines in the 1994 Northridge earthquake and broken water mains in San Francisco in the 1906 earthquake.
Critical facilities exposed to liquefaction risk are summarized in Table 9-9.
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Table 9-9: Critical Infrastructure in High Liquefaction Susceptibility Areas Table 9-9
Critical Infrastructure in High Liquefaction Susceptibility Areas in Monterey County Critical Infrastructure Type High Liquefaction Susceptibility Facilities
Emergency Response 5
Fire Station 7
Police Station 0
Medical Facilities 14
Military Facility 1
Large Public Facilities 0
Educational Facilities 17
Power Plant 1
Water & Wastewater Facilities 87
Stormwater Facilities 7
Government Facilities 53
Communication Facilities 175
Rain Gauges 17
Lighthouses 1
Dams 1
Hazardous Materials
Active or Idle Oil Well 250
Landfill 0
Underground Tank 39
Cal ARP Facility 11
Transportation
Airport 4
Bridge 111
Harbor 1
Highway/Freeway (Miles) 100
Driveway (Miles) 2
Major Road (Miles) 443
Local (Miles) 899
Railroad (Miles) 29
9.4.4 ENVIRONMENT
Environmental problems as a result of an earthquake can be numerous. Secondary hazards will likely have some of the most damaging effects on the environment. Earthquake-induced landslides can significantly damage surrounding habitat. It is also possible for streams to be rerouted after an earthquake. Rerouting can change the water quality, possibly damaging habitat and feeding areas. Streams fed by groundwater wells can dry up because of changes in underlying geology.
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9.4.5 ECONOMIC IMPACT
A large earthquake could have a massive economic impact on Monterey County. The number of economic damages will likely vary greatly due to a variety of factors including magnitude and location of the epicenter. Other than direct economic losses due to an earthquake, indirect economic consequences can occur due to business interruption and loss of functions of utilities.
9.5 FUTURE TRENDS IN DEVEL OPMENT
Land use in the County will be directed by general plans adopted under California’s General Planning Law. The safety elements of the general plans establish standards and plans for the protection of the community from hazards. The information in this plan provides a tool to ensure that there is no increase in exposure in areas of high seismic risk. The geologic hazard portions of the County are heavily regulated under California’s General Planning Law.
Development in the County is also be regulated through building standards and performance measures so that the degree of risk will be reduced. The International Building Code establishes provisions to address seismic risk.
9.6 ISSUES
Important issues associated with earthquakes in Monterey County include the following:
• Unreinforced masonry buildings and building stock built prior to 1975, when seismic provisions became uniformly applied through building code applications, are a major concern in the event of a large earthquake.
• An earthquake could trigger other natural hazard events such as dam failures and landslides, which could severely impact the County.
• A worst-case scenario would be the occurrence of a large seismic event during a flood or high-water event. Levee failures could happen at multiple locations, increasing the impacts of the individual events.
• Citizens would be expected to be self-sufficient up to 3 days after a major earthquake without government response agencies, utilities, private-sector services, and infrastructure components.
• After a major seismic event, Monterey County is likely to experience disruptions in the flow of goods and services resulting from the destruction of major transportation infrastructure across the broader region.
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10. FLOODING
10.1 OVERVIEW
Flooding is the accumulation of water where usually none occurs or the overflow of excess water from a stream, river, lake, reservoir, or coastal body of water onto adjacent floodplains.
Floodplains are lowlands adjacent to water bodies that are subject to recurring floods. Floods are natural events that are considered hazards only when people and property are affected.
Nationwide, floods result in more deaths than any other natural hazard. Physical damage associated with floods includes the following:
• Inundation of structures, causing water damage to structural elements and contents. • Erosion or scouring of stream banks, roadway embankments, foundations, footings for bridge piers, and other features.
• Impact damage to structures, roads, bridges, culverts, and other features from high- velocity flow and from debris carried by floodwaters. Debris may also accumulate on bridge piers and in culverts, increasing loads on these features or causing overtopping. • Destruction of crops, erosion of soil, and deposition of debris and sediment on croplands.
• Release of sewage and hazardous or toxic materials as wastewater treatment plants are inundated, storage tanks are damaged, and pipelines are severed.
10.1.1 FLOODPLAINS
A floodplain is the area adjacent to a river, creek or lake that becomes inundated during a flood. Floodplains may be broad, as when a river crosses an extensive flat landscape, or narrow,
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as when a river is confined in a canyon. Floodplains generally contain unconsolidated sediments (accumulations of sand, gravel, loam, silt, and/or clay), often extending below the bed of the stream. These sediments provide a natural filtering system, with water percolating back into the ground and replenishing groundwater. These are often important aquifers, the water drawn from them being filtered compared to the water in the stream.
Connections between a river and its floodplain are most apparent during and after major flood events. These areas form a complex physical and biological system that not only supports a variety of natural resources but also provides natural flood and erosion control. When a river is separated from its floodplain with levees and other flood control facilities, natural, built-in benefits can be lost, altered, or significantly reduced.
Because they border water bodies, floodplains have historically been popular sites to establish settlements. Human activities tend to concentrate in floodplains for a number of reasons:
water is readily available; land is fertile and suitable for farming; transportation by water is easily accessible; and land is flatter and easier to develop. But human activity in floodplains frequently interferes with the natural function of floodplains. It can affect the distribution and timing of drainage, thereby increasing flood problems. Human development can create local flooding problems by altering or confining drainage channels. This increases flood potential in two ways: it reduces the stream’s capacity to contain flows, and it increases flow rates or velocities downstream during all stages of a flood event. Human activities can interface effectively with a floodplain as long as steps are taken to mitigate the activities’ adverse impacts on floodplain functions.
10.1.2 NATIONAL FLOOD INSURANCE PROGRAM
The NFIP makes federally backed flood insurance available to homeowners, renters, and business owners in participating communities. FEMA has prepared a detailed Flood Insurance Study for Monterey County and all incorporated areas, which was last revised in June of 2017. 34 The study presents water surface elevations for floods of various magnitudes, including the 1% annual chance flood (100-year flood) and the 0.2% annual chance flood (500-year flood).
Base flood elevations and the boundaries of the 100- and 500-year floodplains are shown on Flood Insurance Rate Maps (FIRMs), which are the principal tool for identifying the extent and location of the flood hazard. Participants in the NFIP must, at a minimum, regulate development in floodplain areas in accordance with NFIP criteria. Before issuing a permit to build in a floodplain, participating jurisdictions must ensure that three criteria are met:
• New buildings and those undergoing substantial improvements must, at a minimum, be elevated to protect against damage by the 100-year flood. • New floodplain development must not aggravate existing flood problems or increase damage to other properties.
34 Federal Emergency Management Agency, Flood Insurance Study, Monterey County COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 10-3 FLOODING
• New floodplain development must exercise a reasonable and prudent effort to reduce its adverse impacts on threatened salmonid species.
As listed in Table 10-1, Monterey County and all incorporated cities participate in the NFIP.
Table 10-1: NFIP Coverage
Table 10-1
NFIP Coverage
Jurisdiction Community
Number
Policies
in Force Total Coverage Total Written Premium +
Federal Policy Fee
Carmel-By-The-Sea 060196 29 $9,940,000 $13,888
Del Rey Oaks 060197 19 $6,577,500 $50,436
Gonzales 060198 14 $5,474,500 $18,502
Greenfield 060446 3 $1,050,000 $1,260
King City 060199 17 $4,318,600 $28,721
Marina 060727 45 $13,664,400 $61,833
Monterey 060200 58 $19,847,400 $49,129
Monterey County 060195 1,277 $362,723,300 $1,732,791
Pacific Grove 060201 35 $11,144,000 $14,846
Salinas 060202 317 $95,459,500 $320,007
Sand City 060435 3 $1,400,000 $3,109
Seaside 060203 10 $2,789,000 $3,748
Soledad 060204 1 $350,000 $467
FEMA Regulatory Flood Zones
FEMA defines flood hazard areas as areas expected to be inundated by a flood of a given magnitude. These areas are determined via statistical analyses of records of river flow, storm tides, and rainfall; information obtained through consultation with the community; floodplain topographic surveys; and hydrologic and hydraulic analyses. Flood hazard areas are delineated on FIRMs, which provide the following information:
• Locations of specific properties in relation to Special Flood Hazard Area (SFHAs) • Base flood elevations (1% annual chance) at specific sites • Magnitudes of flood in specific areas
• Undeveloped coastal barriers where flood insurance is not available • Regulatory floodways and floodplain boundaries (1% and 0.2% annual chance floodplain boundaries)
Land area covered by floodwaters of the base flood is the SFHA on a FIRM—an area where NFIP floodplain management regulations must be enforced, and where mandatory purchase of flood insurance applies. This regulatory boundary is a convenient tool for assessing vulnerability and COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 10-4 FLOODING
risk in flood-prone communities because many communities have maps showing the extent of the base flood and likely depths that would occur.
The base flood elevation (the water elevation of a flood that has a 1% chance of occurring in any given year) is one of the most important factors in estimating potential damage from flooding. A structure within a 1% annual chance floodplain has a 26% chance of undergoing flood damage during the term of a 30-year mortgage. The 1% annual chance flood is used by the NFIP as the basis for insurance requirements nationwide. FIRMs also depict 0.2% annual chance flood designations (500-year events). FIRMs, and other flood hazard information can be used to identify the expected extent of flooding from a 1% and 0.2% annual chance event. FIRM maps depict flood zones, defined in Table 10-2.
Table 10-2: FEMA Flood Zones
Table 10-2
FEMA Flood Zones
Flood Zone Definition
Special Flood Hazard Areas (SFHA) Subject to Inundation by 100-Year Flood Zone A No base flood elevations determined
Zone AE Base flood elevations determined
Zone AH Flood depths of 1-3 feet (usually areas of ponding); base flood elevations determined
Zone AO
Flood depths of 1-3 feet (usually sheet flow on sloping terrain); average depths determined; for areas of alluvial fan flooding, velocities also determined
Zone AR
SFHA formerly protected from the 1% annual chance flood by a flood control system that was subsequently decertified; zone AR indicates that the former flood control system is being restored to provide protection from the 1% annual chance or greater flood
Zone A99
Area to be protected from 1% annual chance flood by a federal flood protection system under construction; no base flood elevations determined
Zone VE
Area where waves and fast-moving water can cause extensive damage during the base flood event. Wave heights are larger than 3 feet. A detailed study has been done and BFEs have been calculated.
Other Flood Areas
Zone X (shaded)
Areas of 0.2% annual chance flood (i.e., 500-year flood); areas of 1% annual chance flood with average depths of less than 1 foot or with drainage areas less than 1 square mile; and areas protected by levees from 1% annual chance flood
Other Areas
Zone X (unshaded) Areas determined to be outside the 0.2% annual chance floodplain Zone D Areas in which flood hazards are undetermined, but possible
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Community Rating System (CRS)
The Community Rating System (CRS) is a voluntary program within the NFIP that encourages floodplain management activities that exceed the minimum NFIP requirements. Flood insurance premiums are discounted to reflect the reduced flood risk resulting from community actions that meet the three goals of the CRS: 1) reduce flood losses, 2) facilitate accurate insurance rating, and 3) promote awareness of flood insurance.
Flood insurance premium rates in Community Rating System communities are discounted in increments of 5%. A Class 10 community is not participating in the CRS and receives no discount. A Class 9 community receives a 5% discount for all policies in its Special Flood Hazard Areas, a Class 8 community receives a 10% discount, all the way to a Class 1 community, which receives a 45% premium discount. The CRS classes for local communities are based on 18 creditable activities related to public information, mapping and regulations, flood damage reduction, and flood preparedness. As noted in Table 10-3, Monterey County and the City of Salinas are currently participating in the CRS program.
Table 10-3: Community Ratings System (CRS) Participation Table 10-3
Community Ratings System (CRS) Participation
Community
Name
CRS Entry
Date
Current
Effective Date
Current
Class
Discount for
SFHA
Discount for
Non- SFHA
Monterey County 10/1/1991 10/1/2020 5 25% 10%
Salinas 10/1/1991 10/1/2013 7 15% 5%
10.1.3 TYPES OF FLOODING
In Monterey County four types of flooding occur: riverine flooding, coastal flooding, flash flooding, and stormwater runoff flooding.
Coastal Flooding
Coastal or tidal floods are characterized by inundation of normally dry lands by bay waters, often caused by extreme high tide events that result in shallow flooding of low-lying coastal areas. Colloquially known as “king tides,” extreme high-level tide events are the highest predicted high tide events of the year at a coastal location. These tides exceed the highest water level reached at high tide on an average day and normally occur once or twice per year.
King tide events are the leading cause of flooding near bay waters.
Coastal flooding in Monterey County is generally associated with Pacific Ocean storms in the months of November through February. Coastal flooding in conjunction with high tides and strong winds is a significant hazard.
Riverine Flooding
Riverine flooding is overbank flooding of rivers and streams. Flooding in large river systems typically results from large-scale weather systems that generate prolonged rainfall over a wide geographic area, causing flooding in hundreds of smaller streams, which then drain into the COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 10-6 FLOODING
major rivers. Riverine floodplains range from narrow, confined channels in the steep valleys of mountainous and hilly regions to wide, flat areas in plains and coastal regions. The amount of water in the floodplain is a function of the size and topography of the contributing watershed, the regional and local climate, and land use characteristics. Flooding in steep, mountainous areas is usually confined, strikes with less warning time, and has a short duration. Larger rivers typically have longer, more predictable flooding sequences and broad floodplains.
Flash Flooding
The National Weather Service defines a flash flood as a rapid and extreme flow of high water into a normally dry area, or a rapid water level rise in a stream or creek above a predetermined flood level. Such floods generally begin within 6 hours of the rain event that causes them.
Ongoing flooding can intensify to flash flooding in cases where intense rainfall results in a rapid surge of rising floodwaters.
Flash floods can tear out trees, undermine buildings and bridges, and scour new channels. In urban areas, flash flooding is an increasingly serious problem due to removal of vegetation and replacement of ground cover with impermeable surfaces such as roads, driveways, and parking lots. The greatest risk from flash floods is occurrence with little to no warning. Major factors in predicting potential damage are intensity and duration of rainfall, and steepness of watershed and streams.
Localized Stormwater Flooding
Urban storm drainpipes and pump stations have a finite capacity, and prolonged heavy rainfall contributes to a large volume of runoff resulting in high peak flows of moderate duration.
When rainfall exceeds this capacity, or the system is clogged, water accumulates in the street until it reaches a level of overland release.
Urban drainage systems can play a role in flooding in two ways:
• Drainage systems reduce the amount of time surface water takes to reach surrounding streams, flooding in those streams can occur more quickly and reach greater depths than prior to development in the area
• If stormwater runoff exceeds the capacity of the drainage system, then stormwater runoff flooding can result throughout the system’s service area. This is especially likely when groundwater levels are high and during high tides.
Stormwater flooding may occur outside of recognized drainage channels or delineated floodplains due to a combination of locally heavy precipitation, increased surface runoff, and inadequate facilities for drainage and stormwater conveyance. Such events frequently occur in flat areas and in urbanized areas with large impermeable surfaces. Local drainage may result in “nuisance flooding,” in which streets or parking lots are temporarily closed, and minor property damage occurs.
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10.1.4 WATERSHEDS IN MONTEREY COUNTY
Monterey County consists of four predominant watersheds draining to the Salinas River, the Pajaro River, the Carmel River, and the Big Sur River. These watersheds vary in patterns of land use from rural open space and permanent grazing to farmland and agricultural industrial, to low, medium, and high-density residential use. Increased development over the past 100 years has resulted in increased runoff that poses a flood threat. To accommodate the increasing runoff, many cities and communities in these watersheds have developed an extensive system of channels and storm drain facilities. The overall drainage pattern in the county is from south to north; this is the direction of flow for the Salinas River which is the largest river on the central coast of California. Watersheds in Monterey County are mapped in Figure 10-1.
Figure 10-1
Watersheds in Monterey County
Figure 10-1: Watersheds in Monterey County
Source: Monterey County Water Resources Agency (MCWRA)
The four predominant watersheds are described and listed in order of magnitude, from largest to smallest.
COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 10-8 FLOODING
Salinas River Watershed
The Salinas River Watershed originates 4,000 feet above sea level in the La Panza Range near Santa Margarita in San Luis Obispo County and drains a 4,200 square mile area. The Gabilan and Santa Lucia Ranges are the sources of the principal watercourses in the area. The Salinas River has three main tributaries, namely, the Nacimiento, San Antonio, and Arroyo Seco Rivers. It flows for over 110 miles within Monterey County and empties into the Monterey Bay.
Pajaro River Watershed
The Pajaro River Watershed originates from 4,700 feet above sea level in the Diablo and Gabilan Ranges in San Benito County and drains a 1,300 square mile area. The watershed is bound by the Santa Cruz Mountains in the north, and the Gabilan Range in the south. The watershed area spans four counties, namely, Santa Cruz, Santa Clara, San Benito, and Monterey. The Pajaro River has numerous tributaries, which include Corralitos, Uvas, Llagas, San Benito, Pacheco, and Santa Ana Creeks, and flows for approximately 30 miles where it empties into Monterey Bay.
Carmel River Watershed
The Carmel River Watershed originates 4,000 feet above sea level in the Santa Lucia Range and drains a 256 square mile area. The Carmel River has two main tributaries, Cachagua and Tularcitos Creeks, and flows for approximately 26 miles where it empties into the Pacific Ocean.
Big Sur River Watershed
The Big Sur River Watershed originates from 3,000 feet above sea level along Pine Ridge in the Santa Lucia Mountains and drains a 60 square mile area. The Big Sur River has numerous tributaries which include Redwood Creek, Ventana Creek, Post Creek, and Pfeiffer-Redwood Creek, and flows for approximately 15 miles where it empties into the Pacific Ocean.
10.2 HAZARD PROFILE
10.2.1 HISTORY
Historic records show flooding and flood damage have occurred on a fairly regular basis (every few years) within Monterey County. The County experienced severe damages in:
January 1966: Flood conditions along the length of the Salinas River caused extensive damage during the storm of January 1966. Most of this damage was to agricultural crops; over 32,000 acres were inundated, at an estimated loss of $6,572,000. The cities in the county experienced some flooding and damage, although the rural areas and agricultural production were the most affected, with Salinas Valley agriculture sustaining a $3,755,000 loss. 1969: There were two distinct floods in 1969, one at the end of January and one at the end of February. In each flood, both the Salinas and Carmel Rivers flooded. Damage from the storms was extremely costly, causing an estimated $16 million in damages.
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1978: A series of storms emanating from a southerly direction, caused extensive beachfront and coastal damage. Persistent rains in the Salinas Valley, caused an estimated $20,000,000 in flood damages, flooding more than 20,000 acres of irrigated farmland, with as much as 1,000 acres of the prime farmlands flooded beyond agricultural use for the year.
March 1983: “El Niño” storms brought an extremely unusual series of high tides, storm surges, and storm waves along the coast, and heavy rains causing extensive flooding and erosion in the Salinas Valley. Farmland and roadways were damaged, and Monterey County was declared a disaster area.
January 1995: In January 1995, a 10- to 20-year event caused prolonged and sustained precipitation resulting in extensive flooding throughout the region. Most river valleys were affected, with major damage experienced in the Pajaro Valley and Carmel Valley. Five localized areas within the Carmel Valley area were significantly affected by downstream flooding of the Carmel River. The January 1995 flood damaged 125 residences resulting in an estimated damage cost of approximately $2.5 million. In addition, an estimated $927,000 in damage to public facilities and utilities occurred.
March 1995: From March 10-13, 1995, Monterey County experienced a second significant winter storm which resulted in sustained precipitation falling on already-saturated watersheds.
Devastating flooding occurred throughout the County, particularly along the Carmel, Arroyo Seco, Salinas, and Pajaro Rivers. Damage was extensive throughout the County with virtually every community affected. Pajaro, Castroville, Mission Fields, Carmel Valley, Cachagua, Carmel Highlands, Spreckels, and Big Sur sustained devastating damage. Over 1,500 residences were damaged, including 60 homes which were declared uninhabitable. In addition, an estimated 100 businesses were affected, and the tourism industry sustained substantial losses for a period of several months.
In all, over 11,000 people were directly affected, and major portions of the County's agricultural lands subjected to widespread destruction. At the height of the flood, 63 roads and 15 bridges were closed, including the Highway 1 bridge over the Carmel River. The closure of the Highway 1 bridge over the Carmel River resulted in the complete elimination of access to portions of Carmel Valley, Carmel Highlands, and Big Sur for a period of several days, requiring evacuations to take place with helicopters.
62 roads and three bridges sustained damage. Public and private water systems were damaged, affecting approximately 3,500 homes and businesses. Eight large water systems and over fifty small systems were affected. Many residents were without domestic water service for extended periods. A number of areas were required to boil domestic water prior to use.
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Sewage treatment facilities and private septic systems along all three major rivers (Carmel, Salinas, and Pajaro) were flooded and untreated sewage was released into the rivers. The amount of untreated sewage released could not be confirmed, but it may have been many thousands of gallons. Major treatment plants affected included Carmel Ranch, Watsonville, King City, Soledad, and Gonzales. Gas and electric service provided by Pacific Gas and Electric were affected by the storm, resulting in serious
disruptions in service to widespread areas.
Many public facilities and services were closed
or interrupted, including public schools in
affected communities. Zmudowski State
Beach was closed as a result of the discovery
of 27 barrels of potentially hazardous
materials on the beach.
February 1998: A series of "El Niño" winter
storms hit Monterey County and the close
timing of the rainfall events contributed to
intense flooding and saturated ground. An
estimated 50 roads and highways were closed
or restricted, in most cases due to washouts,
landslides, and mudslides. Several
communities were evacuated, including
Pajaro’s entire population of 3,500 people,
after the levee along the Pajaro River was
breached in several places.
Drinking water quality warnings remained in
effect for certain areas for some time
afterward. By the end of the first week of
February, at least 6,600 homes and businesses
had been without power for varying periods
of time. Countywide losses from that storm
were estimated at over $38 million, with
agriculture-related losses totaling over $7
million and involving approximately 29,000
damaged acres.
In the 1998 storm event, the Las Lomas area
experienced severe damage of eight
residential parcels. Monterey County acquired
the parcels through the Federal Hazard
Mitigation Success Story
Severe Repetitive Loss Property Elevation
In 2015, Monterey County completed the
elevation of a Severe Repetitive Loss (SRL)
structure located along the Carmel River.
Based on historical data and FEMA flood
mapping it can be assumed this structure
would have sustained damages during the
major flood events in 2017 and 2019.
In 2017 damages would have been minimal,
with estimated flooding at 1.5 feet above
the finished floor elevation. This would have
resulted in about $83,652 in damages with
no mitigation. With mitigation, it is
estimated that no damage would have
occurred, a savings of $83,652.
In 2019, significant flooding of up to 6 feet
above the finished floor elevation would
have resulted in approximately $255,718 in
damages with no mitigation. With mitigation
it is estimated that $88,946 in damages
would have resulted from flood depths of 6
feet, a savings of $166,772.
Taking in to account each event, this project
has a combined estimated savings of
$250,424 since its completion in 2015.
COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 10-11 FLOODING
Mitigation Grant Program and all structures were removed. Each parcel was subsequently rezoned to “open space” in perpetuity.
January 2008: A strong coastal storm in January 2008 brought flooding rains, high winds, record high surf, and coastal flooding to Monterey County and resulted in nearly $1 million in property damages. Approximately 30 homes in the Carmel Lagoon area were affected by some degree of flooding.
October 2010: In October 2010, a strong low-
pressure system made its way through
Central California and led to record breaking
heavy rains across the area, causing an
estimated $200,000 in damages. In Salinas,
the Pacific Coast Christian Academy and Little
Lamb Preschool were flooded after Little Bear
Creek breached its banks.
March 2011: A series of systems affected
Monterey County with heavy rain and strong
winds causing an estimated $1 million in
property damages. Nearly 1,300 acres of
crops or croplands were impacted by flooding
from the Salinas River and its tributaries
causing an estimated $1.5 million in losses.
December 2014: An atmospheric river
brought heavy rain, gusty winds, and a strong
winter storm that impacted the region for
several days in mid-December. The Moro Cojo
Slough backed up and flooded homes and
roadway along its banks. Sandbagging
operations were needed to protect the homes
from significant damage. The slough flap
gates were damaged and could not properly
drain the slough into Moss Landing Harbor.
The unincorporated community of Bolsa
Knolls along Santa Rita Creek was flooded
when a nearby levee broke open. Emergency
crews reported that homes on Paul Avenue
and Russell Road where evacuated and more
than 18 inches of water flooded homes in a
short amount of time. Fifteen homes were
Mitigation Success Story
Salinas River Stream Maintenance Program
Monterey County is subject to major flood
events along the Salinas River. In 2016,
programmatic permits were approved for the
Salinas River Stream Maintenance Program
(SMP). The Salinas River SMP was developed
as a collaboration between the Monterey
County Water Resources Agency, the
Resource Conservation District of Monterey
County (RCDMC), the Salinas River Channel
Coalition, the Grower Shipper Association of
Central California, The Nature Conservancy,
and the Conservation Collaborative.
The SMP employs a multi-benefit approach
for stream maintenance that enhances
conveyance capacity of the river corridor by
mimicking the sandy-bottomed river’s
natural, braided form in a manner that
protects habitat, while reducing flood risk.
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flooded and damaged due to flooding along Santa Rita Creek. The heavy rain also overwhelmed the sewage plant in Castroville resulting in a sewage spill. 2016: Monterey County was hit with several significant storm events during the 2016 El Niño winter. The first one took place on January 19, 2016, the second from March 5 and 6, 2016, and the third on March 11, 2016. These storms caused severe roadway damage totaling $7,318,000 in repair costs.
2017: A series of atmospheric river events in January and February of 2017 caused widespread roadway flooding and damage in Monterey County. Combined, the January and February storms caused an estimated $52 million to County roads. 2019: An atmospheric river caused widespread heavy rainfall, roadway flooding, and strong winds. This caused flash flooding in Chualar where homes were flooded, and cars were stranded on a flooded highway. This event caused an estimated $2 million in damages.
10.2.2 LOCATION
Principal Flooding Sources
FEMA’s Flood Insurance Study for Monterey County assessed several creeks, channels, and water bodies, including the following flooding sources:
• Arroyo Seco • El Toro Creek • Salinas River
• Big Sur River • Elkhorn Slough • San Benancio Gulch
• Bixby Creek • Gabilan Creek • San Jose Creek
• Calera Creek • Gonzales Slough • San Lorenzo Creek
• Canyon Del Rey • Harper Creek • San Miguel Canyon Creek • Carmel River • Josselyn Canyon Creek • Santa Rita Creek • Castroville Boulevard Wash • Little Sur River • Seal Rock Creek • Corncob Canyon Creek • Natividad Creek • Tembladero Slough • Del Monte Lake • Pajaro River • Tomasello Creek
• East Branch Gonzales Slough • Pine Canyon Creek • Watson Creek • El Estero Lake
Shallow (1- to 3-foot) and sheet flooding conditions generally occur in the Salinas, Carmel, Pajaro, and Big and Little Sur Valleys. In addition, flooding can occur along the beach, where it is not uncommon to see winter storms produce 15-foot breakers. Flooding in these areas generally occurs during the rainy season, from October to April.
Figure 10-2 shows the extent of the 100-year and 500-year floodplains, as well as the known localized flooding within the entire County according to current effective FIRMs (2017).
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Figure 10-2: FEMA Flood Zones
COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 10-14 FLOODING
Flood Awareness Zones
Flood Awareness Zones have been developed by California DWR to map areas of additional flood threat throughout the state. The intent of the Awareness Floodplain Mapping project is to identify all pertinent flood hazards for areas that are not mapped under the NFIP and to provide the community and residents an additional tool in understanding potential flood hazards currently not mapped as a regulated floodplain. The awareness maps identify the 100-YR flood hazard areas using approximate assessment procedures. These floodplains are shown simply as flood prone areas without specific depths and other flood hazard data.
Figure 10-3
DWR Flood Awareness Zones
Figure 10-3: DWR Flood Awareness Zones
Flood Insurance Claims
A repetitive loss (RL) area is an area where multiple properties in close proximity to each other have experienced repetitive losses from flooding. RL property is a FEMA designation, defined as an insured property that has made two or more claims of more than $1,000 in any rolling 10- year period. RL properties may be classified as a Severe Repetitive Loss (SRL) property under certain conditions. A SRL property has had four or more claims of at least $5,000, or at least two claims that cumulatively exceed the building’s value. A property that sustains repetitive flooding may or may not be on the County’s RL property list for a number of reasons:
COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 10-15 FLOODING
• Not everyone is required to carry flood insurance.
• Owners who have completed the terms of their mortgage or who purchased their property outright may choose not to carry flood insurance and instead bear the costs of recovery on their own.
• The owner of a flooded property that does carry flood insurance may choose not to file a claim. Even insured properties that are flooded regularly with filed claims may not meet the $1,000 minimum threshold to be recognized as an RL property. • The owner adopted mitigation measures that reduce the impact of flooding on the structure, removing it from the RL threat and the RL list.
Many jurisdictions are required to address only the properties on the RL list. These properties are representative of the community’s overall repetitive flooding problem, but do not include all damage. The Privacy Act of 1974 restricts the release of certain types of data to the public.
Flood insurance policy and claims data are included in the list of restricted information. FEMA can only release such data to state and local governments, and only if the data are used for floodplain management, mitigation, or research. Therefore, this plan does not identify RL properties or include claim data for any individual property. Flood insurance statistics on loss can still help identify locations vulnerable to flooding, therefore Table 10-4 summarizes loss statistics by jurisdiction.
Table 10-4: NFIP Loss Statistics for Monterey County
Table 10-4
NFIP Loss Statistics for Monterey County
Jurisdiction Community Number Total Losses Claims Total Net Dollars Paid Carmel-By-The-Sea 060196 3 $127,113
Del Rey Oaks 060197 1 $750
Gonzales 060198 10 $187,853
Greenfield 060446 1 $0
King City 060199 12 $715,518
Marina 060727 0 $0
Monterey 060200 37 $2,654,717
Monterey County 060195 1,163 $23,735,682
Pacific Grove 060201 1 $6,784
Salinas 060202 31 $160,884
Sand City 060435 0 $0
Seaside 060203 2 $125,032
Soledad 060204 0 $0
Total 1,261 $27,714,334
10.2.3 FREQUENCY
Monterey County has experienced 10 significant flood events since 1995. This indicates an approximate 38% chance of a significant and damaging flood event in any given year, with a recurrence interval of 2.6 years. Smaller floods may occur more frequently and are an annual COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 10-16 FLOODING
hazard. The FEMA National Risk Index calculates an annualized frequency value for riverine and coastal flood hazards in Monterey County. For flooding, annualized frequency was based on the number of distinct hazard events that have occurred. Flooding in Monterey County has an annualized frequency of 2.7 distinct coastal flood events per year and 0.95 distinct riverine flood events per year.
10.2.4 SEVERITY
The principal factors affecting flood damage are flood depth and velocity. The deeper and faster flood flows become, the more damage they can cause. Shallow flooding with high velocities can cause as much damage as deep flooding with slow velocity. This is especially true when a channel migrates over a broad floodplain, redirecting high velocity flows and transporting debris and sediment. Although jurisdictions can implement mitigation and take preventative actions to significantly reduce the severity and threat of flood events, some type of residual risk will always exist (i.e., risk of a hazard event occurring despite technical and scientific measures applied to prevent it). Threats associated with residual risk include failure of a reservoir, a dam, levee, or other infrastructure, or a severe flood event that exceeds flood design standards or drainage capacity.
Flood risk has increased with population and urbanization. Increased impervious surfaces and channelization of streams has resulted in increased runoff and intensified flood flows. Increased development in floodplains has put more property and lives at risk for flooding. The damages caused by flooding in the Salinas Valley today, even with the construction of major flood control infrastructure, are far more substantial than they were a century ago. Along the Big Sur coast, streams and rivers draining the steep coastal mountains are subject to short, intense floods, capable of producing significant damage to property. Wildfires also exacerbate flood risk in Big Sur, denuding areas of vegetation, which can lead to increased sheet flow and greater velocities during subsequent rainstorms and causing water quality problems in coastal waters. The impact and severity of coastal flooding is additionally affected by tides, storm surge (the rise in water from wind stress and low atmospheric pressure), waves, and peak still-water elevation.
10.2.5 WARNING TIME
Due to the sequential pattern of meteorological conditions needed to cause serious flooding, it is unusual for a flood to occur without warning. Warning times for floods can be between 24 and 48 hours. Flash flooding can be less predictable, but potential hazard areas can be warned in advanced of potential flash flooding danger. The Monterey County Water Resources Agency (MCWRA) provides flood warning services to Monterey County. MCWRA staff monitors county wide hydrologic conditions during every significant storm event. A real time flood warning system allows MCWRA staff to provide hydrologic data as well as expertise to emergency managers and local law enforcement any hour of the day or night as needed for the protection of life and property in Monterey County.
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10.3 SECONDARY HAZARDS
The most problematic secondary hazard for flooding is erosion, which in some cases can be more harmful than actual flooding. Flooding is also responsible for landslides when high flows over-saturate soils on steep slopes and cause them to fail. Hazardous materials spills are a secondary hazard of flooding if storage tanks rupture and spill into streams or storm sewers. It is also recognized that wildland fires within a watershed can exacerbate the flood hazard by virtue of increased rate and volume of runoff and attendant erosion and sediment discharge.
10.4 RISK ASSESSMENT
10.4.1 POPULATION
As seen in Figure 10-4, in Monterey County, 80,461 people are located in the 1% annual chance flood zone.
Figure 10-4
Population Exposed to Flood Risk
Figure 10-4:Population Exposed to Flood Risk
Floods can be extremely dangerous, and even six inches of moving water can knock over a person given a strong current. A car will float in less than two feet of moving water and can be swept downstream into deeper waters. This is one reason floods kill more people trapped in vehicles than anywhere else. During a flood, people can also suffer heart attacks or electrocution due to electrical equipment short outs.
Certain health hazards are also common to flood events. Standing water and wet materials in structures can become breeding grounds for microorganisms such as bacteria, mold, and viruses. This can cause disease, trigger allergic reactions, and damage materials long after the 10,103
26,848
13,259 12,532
17,719
73,833
43,213
23,274
47,109
14,568
0 10,000
20,000
30,000
40,000
50,000
60,000
70,000
80,000
District 1 District 2 District 3 District 4 District 5
Monterey County Supervisorial District
1% Chance Annual 0.2% Chance Annual
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flood. When floodwaters contain sewage or decaying animal carcasses, infectious disease becomes a concern. Direct impacts, such as drowning, can be limited with adequate warning and public education about what to do during floods. Where flooding occurs in populated areas, warning and evacuation will be of critical importance to reduce life and safety impacts.
10.4.2 PROPERTY
As noted in Table 10-5, about 35,000 residential properties, almost $16 billion in property value, in Monterey County is in a mapped FEMA Flood Zone.
Table 10-5: Residential Property Exposed to Flood Risk by Flood Zone Table 10-5
Residential Property Exposed to Flood Hazard Risk by Flood Zone Supervisorial
District
1% Annual Chance 0.2% Annual Chance
# Value # Value
District 1 340 $215,814,543 9,716 $3,363,261,908
District 2 1,094 $496,002,748 7,941 $3,458,129,047
District 3 656 $183,474,624 3,550 $1,032,959,384
District 4 118 $67,526,512 10,974 $4,751,738,760
District 5 1,992 $2,729,269,901 1,298 $1,043,994,419
Total 4,200 $3,692,088,328 33,479 $13,650,083,518
As noted in Table 10-6, over 20,000 non-residential properties, about $10 billion in property value, in Monterey County is in a mapped FEMA Flood Zone.
Table 10-6: Non-Residential Property Exposed to Flood Risk by Flood Zone Table 10-6
Non-Residential Property Exposed to Flood Hazard Risk by Flood Zone Supervisorial
District
1% Annual Chance 0.2% Annual Chance
# Value # Value
District 1 423 $218,575,592 4,405 $1,607,035,317
District 2 2,697 $854,792,968 3,207 $739,146,623
District 3 2,133 $2,351,465,862 2,193 $724,778,875
District 4 388 $570,972,637 4,513 $1,479,403,355
District 5 1,734 $1,173,086,410 1,022 $508,954,540
Total 7,375 $5,168,893,469 15,340 $5,059,318,710
10.4.3 CRITICAL FACILITIES AND INFRASTRUCTURE
Flood events can significantly impact road bridges. These are important because often they provide the only ingress and egress to some neighborhoods. Roads or railroads that are blocked or damaged can isolate residents and can prevent access throughout the County, including for emergency service providers needing to get to vulnerable populations or to make repairs.
Additionally, underground utilities can be damaged. Water and sewer systems can be affected by flooding. Floodwaters can back up drainage systems, causing localized flooding. Culverts can be blocked by debris from flood events, also causing localized urban flooding. Floodwaters can COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 10-19 FLOODING
get into drinking water supplies, causing contamination. Sewer systems can be backed up or overwhelmed by inflow and infiltration, causing sanitary sewer overflows.
Facilities that are known to manufacture, process, store, or otherwise use hazardous materials could be damaged in a flood. If damaged by a flood, these facilities could release chemicals that cause cancer or other significant adverse acute human health effects, or significant adverse environmental effects. During a flood, containers holding these materials can rupture and leak into the surrounding area, disastrously affecting the environment and residents. Table 10-7 summaries critical infrastructure in the 100-year floodplain in Monterey County.
Table 10-7: Critical Infrastructure in the 100-Year Floodplain Table 10-7
Critical Infrastructure in the 100-Year Floodplain in Monterey County Critical Infrastructure Type 1% Annual Chance
Facilities
Emergency Response 0
Fire Station 2
Police Station 0
Medical Facilities 3
Military Facility 0
Large Public Facilities 0
Educational Facilities 6
Power Plant 0
Water & Wastewater Facilities 61
Stormwater Facilities 8
Government Facilities 20
Communication Facilities 78
Rain Gauges 19
Lighthouses 0
Dams 0
Hazardous Materials
Active or Idle Oil Well 853
Landfill 0
Underground Tank 15
Cal ARP Facility 9
Transportation
Airport 1
Bridge 93
Harbor 3
Highway/Freeway (Miles) 89
Driveway (Miles) 1
Major Road (Miles) 310
Local (Miles) 527
Railroad (Miles) 23
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10.4.4 ENVIRONMENT
Flooding is a natural event, and floodplains provide many natural and beneficial functions.
Nonetheless, flooding can impact the environment in negative ways. Migrating fish can wash into roads or over dikes into flooded fields, with no possibility of escape. Pollution from roads, such as oil, and hazardous materials can wash into rivers and streams. During floods, these can settle onto normally dry soils, polluting them for agricultural uses. Human development such as bridge abutments and levees, and logjams from timber harvesting can increase stream bank erosion, causing rivers and streams to migrate into non-natural courses.
While the vulnerability assessment focuses on human vulnerability to flood events, the impact of human activities on flooding is also worth noting. Due to negative impacts of floods, many structural and other measures have been devised to limit how far a floodplain can extend.
However, floodplains have many natural and beneficial functions, and disruption of natural systems can have long-term consequences for entire regions.
Some well-known, water-related functions of floodplains (noted by FEMA) include:
• Natural flood and erosion control • Filter nutrients and impurities from runoff • Provide flood storage and conveyance • Process organic wastes • Reduce flood velocities • Moderate temperatures of water • Reduce flood peaks • Surface water quality maintenance • Reduce sedimentation • Promote infiltration and aquifer recharge
Areas in the floodplain that typically provide these natural functions are wetlands, riparian areas, sensitive areas, and habitats for rare and endangered species.
10.4.5 ECONOMIC IMPACT
Flooding can result in economic losses through closure of businesses and government facilities, disrupt communications, disrupt the provision of utilities such as water and sewer service, result in excessive expenditures for emergency response, and generally disrupt the normal function of a community.
Locations that are directly flooded experience the greatest economic impact. In these areas, renovations of commercial buildings may be necessary, disrupting associated services.
Significant damage may occur in agricultural areas, with destruction of crops and agricultural products. The tourism industry may be affected by major flood events, as popular vacation areas tend to overlap flood hazard zones. Finally, flooding can cause extensive damage to public utilities and disruptions to delivery of services. Loss of power and communications may occur and drinking water and wastewater treatment facilities may be temporarily out of operation or running on backup generator power.
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10.5 FUTURE TRENDS IN DEVELOPMENT
The planning partners are equipped to handle future growth within flood hazard areas. All municipal planning partners have general plans that address frequently flooded areas in the safety elements of their General Plans. Additionally, all municipal planning partners are participants in the NFIP and have adopted flood damage prevention ordinances in response to its requirements. All municipal planning partners have committed to maintaining their good standing under the NFIP through actions identified in this plan.
10.6 ISSUES
Important issues associated with flooding in Monterey County include the following:
• The accuracy of the existing flood hazard mapping produced by FEMA in reflecting the true flood risk within the County is questionable.
• The effect of climate change on flood risk is uncertain. • More information is needed on flood risk to support the concept of risk-based analysis of capital projects.
• Ongoing flood hazard mitigation will require funding from multiple sources. • Floodplain residents need to continue to be educated about flood preparedness and the resources available during and after floods.
• The concept of residual risk should be considered in the design of future capital flood control projects and should be communicated with residents living in the floodplain. • The promotion of flood insurance as a means of protecting private property owners from the economic impacts of frequent flood events should continue. • The economy affects a jurisdiction’s ability to manage its floodplains. Budget cuts and personnel losses can strain resources needed to support floodplain management.
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11. HAZARDOUS MATERIALS
INCIDENT
11.1 OVERVIEW
According to the Environmental Protection Agency (EPA), a hazardous material is any item or agent (biological, chemical, physical) which has the potential to cause harm to humans, animals, or the environment, either by itself or through interaction with other factors. These substances may be highly toxic, reactive, corrosive, flammable, radioactive, or infectious.
Hazardous materials can be present in any form, gas, solid, or liquid. Environmental or atmospheric conditions can influence hazardous materials if they are uncontained. Hazardous materials include hundreds of substances that pose a significant risk to humans.
Title 49 of the Code of Federal Regulations (CFR) lists thousands of hazardous materials, including gasoline, insecticides, household cleaning products, and radioactive materials. State- regulated substances that have the greatest probability of adversely impacting the community are listed in the CCR, Title 19. Numerous federal, state, and local agencies, including the US Environmental Protection Agency (EPA), US Department of Transportation (DOT), National Fire Protection Association, FEMA, the US Army, and the International Maritime Organization regulate hazardous materials.
Hazardous material releases can pose a risk to life, public health, air quality, water quality and the environment. A release or spill of bulk hazardous materials could result in fire, explosion, toxic cloud or direct contamination of water, people, and property. The effects may involve a
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local area or many square miles. They may result in the evacuation of a facility or an entire neighborhood. In addition to the immediate risk, long-term public health and environmental impacts may result from sustained exposure to certain substances. Damage to property could range from immediate destruction by explosion to permanent contamination by a persistent hazardous material.
Natural hazards may cause the release of hazardous materials and complicate response activities. The impact of earthquakes on fixed facilities may be particularly serious due to the impairment or failure of the physical integrity of containment facilities. The threat of any hazardous material event may be magnified due to restricted access, reduced fire suppression and spill containment, and even complete cut-off of response personnel and equipment.
11.1.1 TYPES OF HAZARDOUS MATERIALS INCIDENTS
The following are the most common types of hazardous material incidents:
• Fixed Facility Hazardous Materials Incident: This is the uncontrolled release from a fixed site of materials that pose a risk to health, safety, and property. Fixed site facilities include refineries, chemical plants, storage facilities, manufacturing facilities, warehouses, wastewater treatment plants, swimming pools, dry cleaners, automotive sales/repair, and gas stations. It is possible to identify and prepare for fixed-site incidents because federal and state laws require those facilities to notify state and local authorities about materials being used or produced at the site. • Hazardous Materials Transportation Incident: A hazardous materials transportation incident is any event during transport resulting in uncontrolled release of materials that can pose a risk to health, safety, and property. Transportation incidents are difficult to prepare for because there is little if any notice about what materials could be involved should an accident happen. Transported hazardous wastes include thousands of shipments of radiological materials moved across the United States by ground transportation, mostly medical materials, and low-level radioactive waste. Hazardous materials transportation incidents can occur on any transportation corridor, although most occur on interstate highways, other major federal or state highways, or major rail lines. Accidents may involve bulk petroleum products, reactive materials, chemical wastes, explosives, and other toxic substances that are being transported or temporarily stored while in transit.
• Interstate Pipeline Hazardous Materials Incident: There are a significant number of interstate natural gas, heating oil, and petroleum pipelines running through the State of California. These are used to provide natural gas to utilities and to transport these materials from production facilities to end-users.
Hazard Materials Classifications
The US Department of Transportation (USDOT) divides hazardous materials into nine major hazard classes. A hazard class is a group of materials that share a common major hazardous property, i.e., radioactivity, flammability, etc. These hazard classes include:
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• Class 1: Explosives
• Class 2: Compressed Gases
• Class 3: Flammable Liquids
• Class 4: Flammable Solids; Spontaneously Combustible Materials; Dangers When Wet Materials/Water-Reactive Substances
• Class 5: Oxidizing Substances and Organic Peroxides
• Class 6: Toxic Substances and Infectious Substances
• Class 7: Radioactive Materials
• Class 8: Corrosives
• Class 9: Miscellaneous Hazardous Materials/Products, Substances, or Organisms
11.1.2 OVERSIGHT
Hazardous materials management is regulated by federal and state codes. The state fire marshal and the Pipeline and Hazardous Materials Safety Administration enforce oil and gas pipeline safety regulations. The federal government enforces hazardous material transport pursuant to its interstate commerce regulation authority. The Department of Toxic Substances Control (DTSC), a Division of the California Environmental Protection Agency, acts to protect California from exposure to hazardous waste by cleaning up existing contamination and looking for ways to reduce the amount of hazardous waste produced. DTSC regulates hazardous waste primarily under the authority of the Federal Resource Conservation and Recovery Act and the California Health and Safety Code. Other laws that affect hazardous waste are specific to handling, storage, transportation, disposal, treatment, cleanup, and emergency planning. DTSC has the authority to implement permitting, inspection, compliance, and corrective action programs to ensure that people who manage hazardous waste follow requirements.
Businesses are required to disclose all hazardous materials and waste above certain designated quantities that they use, store, or handle at their facility. They must prepare chemical inventory and business emergency plans, review the plans regularly, and conduct training. Any release or possible release of hazardous materials must be reported to the Cal OES Warning Center.
Businesses using certain regulated substances (about 260 specific flammable or toxic chemicals) must develop a risk management plan. The plan must include an analysis of operations on-site, and projection of off-site consequences with accompanying mitigation plans.
11.2 HAZARD PROFILE
11.2.1 HISTORY
According to data from Cal OES Warning Center from 2016 through June 2, 2021. The records show 667 hazardous materials spills in Monterey County over the 5-year timeframe. Table 11-1 lists the number of hazardous material incidents by spill site and type of substance spilled in Monterey County reported to the Cal OES Warning Center.
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Table 11-1: Hazardous Materials Spills by Spill Site and Substance Spilled (2016- 2021) Table 11-1
Hazardous Materials Spills in Monterey County by Spill Site and Substance Spilled (2016-2021) Spill Site
Type of Substance Spilled
Chemical Petroleum Radiological Sewage Vapor Unnamed
/ Other
Railroad
Derailment Total
Airport 1 1 2
Industrial 2 4 5 2 13
Business 10 21 29 15 14 89
Military Base 6 3 1 10
Oil Field 17 1 18
Other 7 24 29 7 10 77
Pipeline 1 1
Railroad 1 2 1 1 44 49
Residence 3 8 83 4 3 101
Road 4 51 2 53 2 2 114
School 1 5 1 7
Gas Station 13 1 14
Ship/ Harbor 1 18 1 2 22
Sewage
Facility 1 1 8 2 12
Utilities/
Substation
3 1 4
Waterways 2 106 13 13 134
Total 31 277 2 228 34 51 44 667
Source: Cal OES Spill Release Reporting Data (2016 through June 2, 2021)
As seen in Table 11-2, the most common causes of hazardous materials incidents were unknown (26%), followed by blockages (18%) and mechanical (18%).
Table 11-2: Hazardous Materials Spills by Cause of Spill (2016 -2021) Table 11-2
Hazardous Materials Spills in Monterey County by Cause of Spill (2016-2021) Cause Number
Blockage 121
Broken Pipe 20
Collision 57
Human Error 96
Mechanical 117
Other 67
Overflow 15
Rail 1
Unknown 173
Total 667
Source: Cal OES Spill Release Reporting Data (2016 through June 2, 2021) COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 11-5 HAZARDOUS MATERIALS INCIDENT
Of the 667 reported incidents, 175 (26%) occurred in unincorporated Monterey County, including 49 in the vicinity of Moss Landing (7%). 157 reported incidents (24%) occurred in the City of Monterey and 135 incidents (30%) occurred in the City of Salinas. Additionally, over this 5-year timeframe hazardous material releases have been related to 40 injuries, 16 fatalities, and 23 evacuations. Further historical hazardous material spill report data is available on the Cal OES website.
11.2.2 LOCATION
The following locations have the potential of hazardous materials releases:
• Business and Industrial Facilities: Retail, manufacturing and light industrial firms are areas of concern. These facilities have the highest concentration of hazardous materials at fixed facilities in the planning area due to their manufacturing operations. Anhydrous ammonia and chlorine gas are the two most common extremely hazardous substances used in Monterey County. These materials are used primarily for cold storage by the produce industry, drinking water and wastewater treatment, and water treatment and cooling for pre-cut salad processing. It is anticipated that a release occurring at these businesses would present the greatest likelihood of having an off-site consequence and could have a major impact on the surrounding areas. In addition to these types of businesses, there are several large agricultural chemical wholesalers and applicators that handle large quantities of various pesticides. Another business that may present significant hazards because of the types and quantities of chemicals handled and the proximity to populated areas would include electric power generating facilities.
Approximately 90 businesses have been identified under the California Accidental Release Prevention (CalARP) program as handling and storing a regulated hazardous substance in quantities above the California recognized threshold quantities. • Agricultural Areas: Accidental releases of pesticides, fertilizers, and other agricultural chemicals may be harmful to both humans and the environment. Monterey’s agricultural industry is a heavy user of pesticides and fertilizers, and the incorrect production and storage of these chemicals can only contaminate the soil, air, and water, and can cause a fire or an explosion. Agricultural pesticides are transported daily in and around the County.
• Harbors: Harbors are a potential location for hazardous materials spills. Marine tank vessels and refined petroleum products such as gasoline, diesel and bunker fuel used by ships are sources of potential oil spills. The Monterey and Moss Landing Harbors are potential locations for hazardous materials incidents.
• Illegal Drug Operations: Illegal operations such as laboratories for methamphetamine can pose a threat. Laboratory residues are often dumped along roadways or left in rented hotel rooms, creating a serious health threat to unsuspecting individuals and to the environment.
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• Illegal Dumping Sites: Hazardous wastes such as used motor oil, solvents, or paint are occasionally dumped in remote areas or along roadways, creating a potential health threat to unsuspecting individuals and to the environment. • Transportation Routes: The County’s transportation system consists of a network of federal, state, and county roads, airports, and rail service that all have the potential for hazardous material incidents. The trucks and trains that use these transportation corridors commonly carry a variety of hazardous materials, including gasoline, other crude oil derivatives, and other chemicals known to cause human health problems.
Major transportation routes in the County include:
o US 101, State Route 1 (Highway 1), State Route 156, State Route 183, State Route 68, State Route 198, and County Routes G14, G15, and G18 o Amtrak long distance and intercity trains through the County o Railroad lines
o General Aviation Airports
• Pipelines: This information is provided by the National Pipeline Mapping System and is available to general public. Information does indicate that several pipelines conveying gas or hazardous liquids cross the County.
• Oil Fields: The County’s active oil fields are subject to fire or explosion. The San Ardo Oil Fields are a possible location of a hazardous materials incident.
DTSC Hazardous Waste and Substances Site List (as of May 13, 2021), lists 110 sites in Monterey County with potential to release hazardous materials. Additionally, two sites in Monterey County are currently listed by the EPA on the Federal Superfund National Priorities List (NPL):
Crazy Horse Sanitary Landfill
The Crazy Horse Sanitary Landfill site is a 125-acre sanitary landfill in Salinas, California. A landfill has operated on site since 1950. The landfill is owned by the City of Salinas and operated by Salinas Disposal Services. The facility receives about 162,000 tons of refuse a year.
Landfill operations contaminated groundwater with hazardous chemicals. Following initial actions to protect human health and the environment, EPA is evaluating whether additional cleanup measures are needed.
Fort Ord
The 27,827-acre Fort Ord site was established in 1917 by the US Army as a maneuver area and field artillery target range. In 1991, Fort Ord was selected for decommissioning, but the post did not formally close until 1994. Prior to closing in September 1994, the base's primary mission was training infantry military personnel. The EPA placed the site on the Superfund program’s National Priorities List (NPL) in 1990. The site contained leaking petroleum underground storage tanks, a 150-acre landfill used to dispose of residential waste and small amounts of commercial waste generated by the base, a former fire drill area, motor pool maintenance areas, small dumpsites, small arms target ranges, an 8,000-acre firing range and other limited areas that pose threats from unexploded ordnance.
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On November 20, 2020, the EPA published a Federal Register notice announcing its proposal to remove 11,934 acres of the 27,827-acre Fort Ord Superfund site from the NPL. This deletion is a “partial deletion” (meaning it includes only a part of the cleanup at a portion of the site where cleanup is finished); and only covers cleanup work for military munitions and soil pollution. EPA and the State of California will continue to oversee the US Army’s cleanup at the rest of the site.
The Army is the lead federal agency for the cleanup. The Army will continue to clean up the groundwater and soil gas on the 11,934 acres. It will also cleanup all pollution at the remaining 15,893 acres of the site. Both the groundwater and soil cleanup for the 11,934 acres and the entirety of the 15,893 acres are still in the Superfund program.
11.2.3 FREQUENCY
Hazardous material incidents may occur at any time in the County, given the presence of transportation routes dividing the County, the location of businesses and industry that use hazardous materials, the presence of scattered illegitimate businesses such as clandestine drug laboratories, and the improper disposal of hazardous waste. Based on previous occurrences (as noted above 667 incidents occurred over a 5-year period), Monterey County can expect small hazardous material incidents to occur many times a year. The likelihood of a significant hazardous materials release within the County is more limited and difficult to predict but is assumed to be highly likely.
11.2.4 SEVERITY
Hazardous materials come in the form of explosives, flammable and combustible substances, poisons, and radioactive materials. Hazards can occur during production, storage, transportation, use or disposal. The release or spill of hazardous materials requires a different response depending on factors such as the amount, type, and location of the spill. Each location should have its own specific cleanup procedure, and all personnel handling such material should have received instruction on that procedure. The speed of onset of a hazardous materials spill is generally short. The duration is typically short as well, though certain chemicals can pollute earth and groundwater for long periods of time. Comprehensive information on the probability and magnitude of a hazardous material event is not available. Wide variations among the characteristics of hazardous material sources and among the materials themselves make such an evaluation difficult.
11.2.5 WARNING TIME
Hazardous material incidents occur without predictability under circumstances that give responders little time to prepare.
11.3 SECONDARY HAZARDS
Roadway or railroad closures due to a transportation-related hazardous material spill would have serious effects on the local economy and ability to provide services. Loss of major travel COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 11-8 HAZARDOUS MATERIALS INCIDENT
routes would result in loss of commerce and could impact the ability to provide emergency services to citizens. The ability to receive fuel deliveries could be impacted. It is also common to see hazardous materials releases as escalating incidents resulting from other hazards such as floods, wildfires, and earthquakes. The release of hazardous materials can greatly complicate or even eclipse the response to the natural hazards disaster that caused the spill.
11.4 RISK ASSESSMENT
To assess hazardous materials incident risk, buffer distances were used. The chosen buffer distance was based on guidelines in the US Department of Transportation’s Emergency Response Guidebook that suggests distances useful to protect people from vapors resulting from spills involving dangerous and toxic substances. The recommended buffer distance, or “protective action distance” is the area surrounding the incident in which people are at risk of harmful exposure. For this plan, a buffer distance of one mile was used, but actual buffer distances will vary depending on the nature and quantity of the release, whether the release occurred during the night or daytime, and prevailing weather conditions.
To analyze the risk in the County to a transportation-related hazardous materials release, a one-mile buffer was applied to highways in the US Dept of Transportation, National Transportation Atlas Database. The result is a two-mile buffer zone around each transportation corridor that is used for this analysis. Risk from a fixed facility hazardous materials release was analyzed using a one-mile buffer applied to facilities identified in the Monterey County 2019 Hazardous Materials Plan.
11.4.1 POPULATION
As seen in Table 11-3, close to 250,000 people could be exposed to mobile source hazardous materials incidents, and a little over 100,000 people could be exposed to a fixed source hazardous materials incident.
Table 11-3: Population Exposed to Hazardous Materials Incident Risk Table 11-3
Population Exposed to Hazardous Materials Incident Risk in Monterey County Supervisorial District Mobile Source Fixed Source
District 1 43,569 46,909
District 2 41,632 15,718
District 3 64,443 35,240
District 4 58,962 16,439
District 5 40,379 2,956
Total 248,985 117,262
Variables affecting exposure in the event of a hazardous materials incident include the type of product, the physical and chemical properties of the substance, the physical state of the product, the ambient temperature, wind speed, wind direction, barometric pressure, and COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 11-9 HAZARDOUS MATERIALS INCIDENT
humidity. With so many variables, true population exposure numbers are difficult to determine.
In general, those who live near transportation corridors or businesses with hazardous materials are more at risk; but each chemical incident is different, and the scenarios are numerous.
Hazardous materials pose a significant risk to emergency response personnel. All potential first responders and follow-on emergency personnel in the County currently are and will be properly trained to the level of emergency response actions required of their individual position at the response scene. Hazardous materials incidents can also pose a serious long-term threat to public health, and those who already are at high risk of health complications, the young, and the elderly, may be more vulnerable to health impacts.
11.4.2 PROPERTY
During a hazardous materials transportation spill, it is generally people that are at risk to the effects of the spill. During a spill, buildings, property, and their values are at a lesser risk; however, given the location of hazardous materials in the County, an analysis is performed here.
Table 11-4 and Table 11-5 summarizes property that is exposed to hazardous material incident risk from fixed and mobile source.
Table 11-4: Residential Property Exposed to Hazardous Materials Incident Risk Table 11-4
Residential Property Exposed to Hazardous Materials Incident Risk in Monterey County Supervisorial
District
Mobile Source Fixed Source
# Value # Value
District 1 5,374 $2,014,276,564 5,348 $1,709,901,633
District 2 7,762 $3,094,087,641 1,400 $529,147,582
District 3 8,823 $2,722,732,839 5,114 $1,607,471,282
District 4 11,156 $5,267,765,844 3,512 $1,511,657,663
District 5 12,968 $14,243,375,574 526 $327,493,551
Total 46,083 $27,342,238,462 15,900 $5,685,671,711
Table 11-5: Non-Residential Property Exposed to Hazardous Materials Incident Risk Table 11-5
Non-Residential Property Exposed to Hazardous Materials Incident Risk in Monterey County Supervisorial
District
Mobile Source Fixed Source
# Value # Value
District 1 3,969 $1,574,141,766 3,170 $1,315,727,602
District 2 5,299 $1,581,922,328 1,218 $575,693,618
District 3 5,047 $3,361,071,791 2,978 $1,866,871,670
District 4 5,799 $2,233,416,936 1,878 $675,704,517
District 5 7,444 $3,435,240,541 180 $36,676,356
Total 27,558 $12,185,793,362 9,424 $4,470,673,763
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11.4.3 CRITICAL FACILITIES AND INFRASTRUCTURE
Hazardous materials may be stored at or transported along critical facilities. These facilities are susceptible to accidents and are visible targets for terrorism. The impact of a hazardous material spill or transportation incident will likely be localized to the particular facility, hospital, port, airport, railroad, road, highway, or interstate. The potential losses vary because of the variable nature of the hazardous material spill, but costs from product loss, property damage and decontamination and other costs can add up to millions of dollars. Critical infrastructure exposed to hazardous materials risk is summarized in Table 11-6.
Table 11-6: Critical Infrastructure Exposed to Hazardous Mat erials Incident Risk Table 11-6
Critical Infrastructure Exposed to Hazardous Materials Incident Risk in Monterey County Critical Infrastructure Type Mobile Source Fixed Source Facilities
Emergency Response 36 11
Fire Station 32 9
Police Station 0 5
Medical Facilities 0 22
Military Facility 3 0
Large Public Facilities 3 1
Educational Facilities 119 48
Power Plant 1 0
Water & Wastewater Facilities 233 61
Stormwater Facilities 4 6
Government Facilities 151 103
Communication Facilities 890 335
Rain Gauges 12 2
Lighthouses 1 0
Dams 0 0
Hazardous Materials
Active or Idle Oil Well 1522 20
Landfill 0 1
Underground Tank 121 -
Cal ARP Facility 72 -
Transportation
Airport 5 2
Bridge 52 12
Harbor 1 0
Highway/Freeway (Miles) - 73
Driveway (Miles) - 0
Major Road (Miles) - 133
Local (Miles) - 283
Railroad (Miles) - 23
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11.4.4 ENVIRONMENT
The risk of hazardous material spills to the environment is considerable. Hazardous materials spilled along roads or railways can pollute rivers, streams, wetlands, riparian areas, and adjoining fields. Other hazardous materials released into the air can severely impact plant and animal species. Reducing risk exposure to the built environment will also mitigate potential losses to the natural environment.
Depending on the characteristic of the hazardous material or the volume of product involved, the affected area can be as small as a room in a building or as large as many square miles that require soil remediation. More widespread effects occur when a product contaminates the municipal water supply or water system such as a port, river, lake, or aquifer. Such environmental damage can linger for decades.
11.4.5 ECONOMIC IMPACT
Hazardous materials incidents in Monterey County have the potential to impact many important economic sectors. Large hazardous material spills can drive away tourists. Hazardous materials incidents could impact the agricultural industry, which could have large economic implications.
11.5 FUTURE TRENDS IN DEVELOPMENT
The number and types of hazardous chemicals stored in and transported through the County will likely continue to increase. As population grows, the number of people vulnerable to the impacts of hazardous materials spills will increase. Development will continue to happen within hazardous materials incident risk zones.
Population and business growth along major transportation corridors increases the vulnerability to transportation-related hazardous material spills. Those who choose to develop in these areas should be made aware of the risks associated with living within close proximity to hazardous materials risk.
11.6 ISSUES
Key issues associated with hazardous materials incidents in Monterey County include:
• Train first responders and all appropriate local government staff to implement protocols contained in the Monterey County Hazardous Materials Plan. • Anhydrous ammonia and chlorine gas, two chemicals commonly used in industrial processing in Monterey County are anticipated to present the greatest likelihood of having an off-site consequence and could have a major impact on the surrounding areas. The County should continue to monitor and regulate the use of these chemicals. • Power generating facilities present a hazardous materials release risk.
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• Accidental releases of pesticides, fertilizers, and other agricultural chemicals are a concern due to their potential to have harmful effects on both humans and the environment. • Work proactively with hazardous materials facilities to follow best management practices:
o Placards and labeling of containers
o Emergency plans and coordination
o Standardized response procedures
o Notification of the types of materials being transported through the County at least annually
o Random inspections of transporters as allowed by each company o Installation of mitigating techniques along critical locations o Routine hazard communication initiatives
o Consideration of using alternative products that are safer COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 12-1 HUMAN-CAUSED HAZARDS
12. HUMAN-CAUSED HAZARDS
12.1 OVERVIEW
Although the Disaster Mitigation Act does not require an assessment of human-caused hazards, the Monterey County Steering Committee decided to include human-caused hazards in this hazard mitigation plan for the following reasons:
• Monterey County takes a proactive approach to disaster preparedness in order to protect the public safety of all citizens.
• Preparation for and response to a human-caused disaster involves much of the same staff, training, critical decision making, and commitment of resources as a natural hazard.
• The multi-hazard mitigation planning effort is an opportunity to inform the public about all hazards, including human-caused hazards.
• The likelihood of a human-caused hazard event in the County is greater than that of several of the natural hazards identified in this Plan. • During public outreach events, many community members expressed concern for increasing amounts of human-caused hazards.
The following human-caused hazards discussed in this plan: Cyber-Attack, Targeted Violence, Terrorism, and Mass Migration.
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12.1.1 CYBER- ATTACK
A cyber-attack is an intentional and malicious crime that compromises the digital infrastructure of a person or organization, often for financial or terror-related reasons. Such attacks vary in nature and are perpetrated using digital mediums or sometimes social engineering to target human operators. Generally, attacks last minutes to days, but large-scale events and their impacts can last much longer. As information technology continues to grow in capability and interconnectivity, cyber-attacks become increasingly frequent and destructive.
Types of Cyber-Attacks
Cyber-threats differ by motive, attack type and perpetrator profile. Motives range from the pursuit of financial gain to political or social aims. Cyber-threats are difficult to identify and combat. Types of threats include using viruses to erase entire systems, breaking into systems, and altering files, using someone’s personal computer to attack others, or stealing proprietary, protected, or confidential information. The spectrum of cyber-risks is limitless, with threats having a wide range of effects on the individual, community, and all private and public organizations. This risk assessment includes cyber-attacks and cyber-terrorism under the inclusive hazard of cyber-threats. The terms often are used interchangeably, though they are not the same. While all cyber-terrorism is a form of cyber-attack, not all cyber-attacks are cyber-terrorism.
Public and private computer systems can experience a variety of cyber-attacks, from blanket malware infection to targeted attacks on system capabilities. Cyber-attacks specifically seek to breach Information Technology (IT) security measures designed to protect an individual or organization. The initial attack is followed by more severe attacks for the purpose of causing harm, stealing data, or financial gain. Organizations are prone to different types of attacks that can be automated or targeted.
Ransomware Attacks
Ransomware attacks, a type of cyber-attack, is becoming increasingly common against individuals, small- and medium-sized organizations, utilities, and local governments. Cyber ransom occurs when an individual downloads ransom malware, or ransomware, often through phishing, and the subsequent execution of code results in encryption of all data and personal files stored on the system. The victim then receives a message that demands a fee in the form of electronic currency or cryptocurrency, such as Bitcoin, for the decryption code. Cyber-attacks often target government networks to gain access to sensitive personal information of citizens and employees, as well as proprietary software, strategic plans, and other information.
Prior to the COVID-19 pandemic, state and local governments were already plagued by cybersecurity threats. Ransomware attacks, in which the attacker encrypts a system and demands money to unlock it, have increasingly impacted government entities across the nation over the past two years.
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Cyber-Terrorism
Cyber-terrorism is the use of computers and information, particularly over the Internet, to recruit others to an organization’s cause, cause physical or financial harm, or cause a severe disruption of infrastructure service. Such disruptions can be driven by religious, political, or other motives. Like traditional terrorism tactics, cyber-terrorism seeks to evoke strong emotional reactions, but it does so through information technology rather than a physically violent or disruptive action. Cyber-terrorism has three main types of objectives:
• Organizational: Cyber-terrorism with an organizational objective includes specific functions outside of or in addition to a typical cyber-attack. Terrorist groups today use the internet on a daily basis. This daily use may include recruitment, training, fundraising, communication, or planning. Organizational cyber-terrorism can use platforms such as social media as a tool to spread a message beyond country borders and instigate physical forms of terrorism. Additionally, organizational goals may use systematic attacks as a tool for training new members of a faction in cyber-warfare. • Undermining: Cyber-terrorism with undermining as an objective seeks to hinder the normal functioning of computer systems, services, or websites. Such methods include defacing, denying, and exposing information. While undermining tactics are typically used due to high dependence on online structures to support vital operational functions, they typically do not result in grave consequences unless undertaken as part of a larger attack.
• Destructive: The destructive objective for cyber-terrorism is what organizations fear most. Through the use of computer technology and the Internet, terrorists seek to inflict destruction or damage on tangible property or assets, and death or injury to individuals.
12.1.2 TARGETED VIOLENCE
Targeted violence refers to any incident of violence in which an attacker selects a particular target prior to the violent attack. Unlike terrorism, targeted violence includes attacks otherwise lacking a clearly discernible political, ideological, or religious motivation, but that are of such severity and magnitude as to suggest an intent to inflict a degree of mass injury, destruction, or death commensurate with known terrorist tactics. Targeted violence has a significant impact on the safety and security of communities, schools, places of worship, and other public gatherings.
The threats of terrorism and targeted violence increasingly intersect with one another.
Active shooter attacks are typically motivated by the desire to maximize human casualties. They are differentiated from other attack types by the indiscriminate nature of the victim’s targets of opportunity rather than actions directed toward a specific target. Active shooter attacks have evolved over the last decade ranging from “lone wolf” shooters who act alone and without any organizational affiliation to organized groups acting in concert to achieve a specific objective.
An active shooter is an individual actively engaged in killing or attempting to kill people in a confined and populated area; in most cases, active shooters use firearms and there is no COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 12-4 HUMAN-CAUSED HAZARDS
pattern or method to their selection of victims. Active shooter situations are unpredictable and evolve quickly. Typically, the immediate deployment of law enforcement is required to stop the shooting and mitigate harm to victims. Active shooter situations are often over within 10 to 15 minutes, before law enforcement arrives on the scene.
12.1.3 TERRORISM
Terrorism is defined in the Code of Federal Regulations as “the unlawful use of force and violence against persons or property to intimidate or coerce a government, the civilian population, or any segment thereof, in furtherance of political or social objectives” (28 CFR, Section 0.85). The FBI categorizes two types of terrorism in the US:
• Domestic terrorism involves groups or individuals without foreign direction whose terrorist activities, including the use of WMDs, are directed at the government or population. The FBI, the primary response agency for domestic terrorism, coordinates domestic preparedness programs and activities to limit domestic terrorism. • International terrorism involves groups or individuals whose terrorist activities are foreign-based and/or directed by countries or groups outside the United States, or whose activities transcend national boundaries.
Terrorism can be perpetrated through several methods including Weapons of Mass Destruction (WMD), which includes biological, chemical, nuclear, and radiological weapons; arson, incendiary, explosive, and armed attacks; industrial sabotage and intentional hazardous materials releases; agriterrorism; and “cyber-terrorism.” Within these general categories, however, there are many variations. Particularly in the area of biological and chemical weapons, there are a wide variety of agents and ways for them to be disseminated. Table 12-1 provides a hazard profile summary for terrorism-related hazards.
Table 12-1: Event Profiles for Terrorism
Table 12-1
Event Profiles for Terrorism
Hazard Application
Mode
Hazard Duration/ Extent Mitigating and Exacerbating
Conditions
Conventional
Bomb/
Improvised
Explosive
Device
Detonation of
explosive device
on or near target;
delivery via
person, vehicle,
or projectile.
Instantaneous; additional
"secondary devices" may be
used, lengthening the time
duration of the hazard.
Extent of damage is
determined by type and
quantity of explosive. Effects
generally static other than
cascading consequences,
incremental structural
failure.
Overpressure at a given standoff is
inversely proportional to the cube of
the distance from the blast; thus,
each additional increment of standoff
provides progressively more
protection. Terrain, structures, etc.
can provide shielding by absorbing
and/or deflecting energy/debris.
Exacerbating conditions: ease of
access to target; lack of shielding;
poor construction; ease of device
concealment.
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Table 12-1
Event Profiles for Terrorism
Hazard Application
Mode
Hazard Duration/ Extent Mitigating and Exacerbating
Conditions
Chemical
Agent
Liquid/aerosol
contaminants
dispersed using
sprayers or other
aerosol
generators;
liquids vaporizing
from puddles/
containers; or
munitions.
Chemical agents may pose
viable threats for hours to
weeks depending on the
agent and the conditions in
which it exists.
Contamination can be
carried out of the initial
target area by persons,
vehicles, water, and wind.
Chemicals may be corrosive
or otherwise damaging over
time if not remediated.
Air temperature affects evaporation
of aerosols. Ground temperature
affects evaporation of liquids.
Humidity can enlarge aerosol
particles, reducing inhalation hazard.
Precipitation can dilute but also
spread agent. Wind can disperse
vapors but cause target area to be
dynamic. Micro-meteorological
effects of buildings/terrain can alter
travel and duration of agents.
Sheltering in place can protect people
from harmful effects.
Arson/
Incendiary
Attack
Initiation of fire
or explosion on
or near target via
direct contact or
remotely via
projectile.
Generally, minutes to hours.
Extent of damage
determined by type and
quantity of device,
accelerant, and materials
present at or near target.
Mitigation factors include built-in fire
detection and protection systems and
fire-resistive construction. Inadequate
security can allow easy access to
target and easy concealment of
incendiary device. Noncompliance
with fire and building codes, as well as
failure to maintain existing fire
protection systems, can increase the
effectiveness of a fire weapon.
Armed Attack Tactical assault or
random attack.
Generally, minutes to days.
Extent varies based on
perpetrators’ intent and
capabilities.
Inadequate security can allow easy
access to target, easy weapons
concealment, and undetected
initiation of attack.
Biological
Agent
Liquid or solid
contaminants
dispersed using
aerosols or by
point or line
sources such as
munitions, covert
deposits, moving
sprayers.
Hours to years, depending
on the agent and the
conditions in which it exists.
Depending on the agent
used and the effectiveness
of deployment, agent can
spread via wind and water.
Infection can spread via
humans or animals.
Altitude of release above ground can
affect dispersion; sunlight is
destructive to many bacteria and
viruses; light to moderate wind will
disperse agents but higher winds can
break up aerosol clouds; the micro-
meteorological effects of buildings
and terrain can influence
aerosolization and travel of agents.
Cyber-
Terrorism
Electronic attack,
one computer
against another.
Minutes to days. Generally,
no direct effects on built
environment.
Inadequate security can allow access
to critical computer systems, letting
them to be used to conduct attacks.
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Table 12-1
Event Profiles for Terrorism
Hazard Application
Mode
Hazard Duration/ Extent Mitigating and Exacerbating
Conditions
Agriterrorism
Direct, covert
contamination of
food supplies or
introduction of
pests or disease
agents to crops
and livestock.
Days to months. Extent
varies by type of incident.
Food contamination may be
limited to specific sites,
while pests and diseases
may spread widely.
Inadequate security can facilitate
adulteration of food and introduction
of pests and disease agents to crops
and livestock.
Radiological
Agent
Radioactive
contaminants
dispersed using
sprayers/ aerosol
generators, or by
point or line
sources.
Seconds to years, depending
on material used. Initial
effects will be localized to
site of attack; based on
climatic conditions,
successive behavior of
material may be dynamic.
Duration of exposure, distance from
source of radiation, and the amount
of shielding between source and
target determine exposure to
radiation
Nuclear
Bomb
Detonation of
nuclear device
underground, at
the surface, in
the air, or at high
altitude.
Light/heat flash and
blast/shock wave last
seconds; nuclear radiation
and fallout can persist for
years. Initial blast effects of a
subsurface, ground or air
burst are static, determined
by device’s characteristics/
employment; fallout of
radioactive contaminants
may be dynamic.
Harmful effects of radiation can be
reduced by minimizing the time of
exposure. Light, heat, and blast
energy decrease logarithmically as a
function of distance from seat of
blast. Terrain, forestation, structures,
etc. can provide shielding by
absorbing and/or deflecting radiation
and radioactive contaminants.
Intentional
Hazardous
Material
Release
Solid, liquid,
and/or gaseous
contaminants
released from
fixed or mobile
containers
Hours to days. Chemicals
may be corrosive or
otherwise damaging over
time. Explosion and/or fire
may be subsequent.
Contamination may be
carried out of the incident
area by persons, vehicles,
water, and wind.
Weather conditions directly affect
how the hazard develops. The micro-
meteorological effects of buildings
and terrain can alter travel and
duration of agents. Sheltering in place
can protect people and property from
harmful effects. Non-compliance with
fire and building codes, as well as
failure to maintain existing fire
protection and containment features,
can substantially increase the damage
from a hazardous materials release.
Source: FEMA 386-7, State and Local Mitigation Planning How-To Guide: Integrating Manmade Hazards
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The effects of terrorism can include injuries, loss of life, property damage, or disruption of services such as electricity, water supplies, transportation, or communications. Effects may be immediate or delayed. Terrorists often choose targets that offer limited danger to themselves and areas with relatively easy public access. Foreign terrorists look for visible targets where they can avoid detection before and after an attack, such as international airports, large cities, major special events, and high-profile landmarks.
In dealing with terrorism, the unpredictability of human beings must be considered. People with a desire to perform such acts may seek out targets of opportunity that may not fall into established lists of critical areas or facilities. First responders train to respond not only to organized terrorism events, but also to random acts by individuals who, for a variety of reasons ranging from fear to emotional trauma to mental instability, may choose to harm others and destroy property. While education, heightened awareness, and early warning of unusual circumstances may deter terrorism, intentional acts that harm people and property are possible at any time. Public safety entities must react to the threat, locating, isolating, and neutralizing further damage and investigating potential scenes and suspects to bring criminals to justice.
12.1.4 MASS MIGRATION
Population migration of large scales can lead to resource pressure - such resources include water, gasoline, housing, transportation, first responders, medical care, government services - on communities receiving the migrants and can exacerbate existing instability. In communities lacking the capacity to manage a rapid influx or exodus or already managing underlying threats, migration of this scale greatly increases the potential to destabilize communities. Types of mass migration include large gatherings, planned events, tourism, migrant agriculture, and permanent retreats from hazard impacted areas.
Large Gatherings/ Special Events
Large gatherings refer to a planned or spontaneous event, indoors or outdoors, with a significant number of people participating or in attendance such as a community event or gathering, concert, festival, conference, parade, wedding, protests, or sporting event.
Special events result in concentrations of large numbers of people in limited geographic areas.
Such concentrations exacerbate the effects of any other hazard that may result from or be coincidental to the event. Special events may increase the likelihood of human-caused hazards such as terrorism, civil unrest or high-occupancy building fires. Injuries and/or loss of life may be much greater if naturally occurring hazards such as earthquakes or adverse weather occur during a special event. Simply having a massive concentration of people requires additional planning and caution, regardless of the special risks associated with any particular event. Large- scale special events require the deployment of police, fire, and emergency medical personnel, rendering these resources unavailable for response to emergencies in other locations in the community. Many large-scale special events result in street closures and increased traffic congestion, slowing response time for emergency personnel and equipment.
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Transient and Non-Resident Populations
The physical location and the geographic terrain of Monterey County has created a nexus for several economic drivers which attract transient, non-resident populations. In Monterey County, the Agriculture and Tourism sectors experience seasonal fluctuations, and subsequently an ongoing high rate of population influx and outflow.
A migrant farmworker is defined as an individual who is required to be absent from a permanent place of residence for the purpose of seeking employment in agricultural work. Due to the seasonal nature of agriculture, workers travel and work throughout the US, serving as the backbone for this major industry. The National Agricultural Workers Survey (NAWS) defines a migrant farmworker as a person who reported jobs that were at least 75 miles apart or who reported moving more than 75 miles to obtain a farm job during a 12-month period. While the vast majority of farmworkers in the US are settled (81%), around 19% are migratory. 35 California growers employ one out of three of the nation’s farmworkers. Annual influxes of agricultural workers can place a strain on local resources.
Over the past decades, global tourism industry has been growing exponentially, more than doubling between 1992 and 2012. By 2030, annual international tourism is estimated to grow to up to 1.8 billion.36 Therefore, tourism is becoming globally one of the most important economic activities, at the same time, the sector is regularly challenged by crises caused by natural, man-made or other often subjective risks. Risks associated with the tourism industry include:
• Tourism infrastructure is often located in areas exposed to sudden-onset natural disasters, in particular beach and coastal areas, river valleys and mountain regions. • Many natural disasters, crime incidents, epidemics, acts of terrorism and civil strife are either deliberately targeted at places where tourists gather or coincidentally occur in areas with high concentrations of tourists.
• Tourists often lack familiarity with a destination region, local customs, language, or a lack of awareness of local security risks and threats often result in the tourists having a higher propensity to find themselves in dangerous situations than many local residents. • As seen during the COVID-19 Pandemic, tourism has also been a significant contributing factor in the rapid spread of infectious diseases.
• A large-scale disaster is likely to stretch the capacity of emergency services in any jurisdiction, but large tourist populations can further strain the capabilities of medical, emergency rescue, police, ambulance, and hospital services to cope with a disaster. • While residents are normally easy to locate and identify by local emergency agencies, tourists by virtue of their transient presence are not.
35 Findings from the National Agricultural Workers Survey (NAWS) 2015-2016: A Demographic and Employment Profile of United States Farmworkers. JBS International (January 2018). 36 Tourism and Disaster Risk. UN World Conference on Disaster Risk Reduction (2015) COUNTY OF MONTEREY Multi-Jurisdictional Hazard Mitigation Plan PAGE | 12-9 HUMAN-CAUSED HAZARDS
Retreat from Hazard Impacted Areas
One of the most pressing concerns relates to the growth in climate-induced migration. In 2017,
68.5 million people were forcibly displaced, more than at any point in human history. While it is difficult to estimate, approximately one-third of these (22.5 million to 24 million people) were forced to move by “sudden onset” weather events, such as flooding, wildfires, and intensified storms.37 While the remaining two-thirds of displacements are the results of other crises, it is becoming apparent that climate change is contributing to so-called slow onset events such as desertification, sea-level rise, ocean acidification, air pollution, rain pattern shifts and loss of biodiversity. Put simply, climate change will cause population movements by making certain parts of the world much less viable places to live; by causing food and water supplies to become more unreliable and increasing the frequency and severity of floods and storms. Migration is possibly the most direct adaptation strategy to climate change. As climate change continues with tremendous changes in local living conditions, populations in communities with worsening conditions consider moving to better places, provided the costs of migration are affordable.