HomeMy WebLinkAbout2011-06-21; City Council; 20589 PART2; 2010 UPDATE SD COUNTY HAZARD MITIGATION PLANMULTI-JURISDICTIONAL
HAZARD MITIGATION
PLAN
Carlsbad
Chula Vista
Coronado
Del Mar
El Cajon
Encinitas
Escondido
Imperial Beach
La Mesa
Lemon Grove
Participating
Jurisdictions:
National City
Oceanside
Poway
San Diego
San Marcos
Santee
Solana Beach
Vista
County of San Diego
Rancho Santa Fe FPD
UDC
August 2010
SAN DIEGO COUNTY
MULTI-JURISDICTION HAZARD
MITIGATION PLAN
SAN DIEGO COUNTY, CALIFORNIA
AUGUST 2010
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TABU Or CONTENTS
Section 1 Introduction 1-1
1.1 Plan Description/Purpose of Plan 1-1
1.2 Plan Purpose and Authority 1-2
1.3 Community Description 1-3
1.3.1 The County of San Diego 1-3
1.3.2 Local Jurisdictions 1-6
Section 2 Multi-Jurisdictional Participation Information 2-1
2.1 List of Participating and Non-Participating Jurisdictions 2-1
2.2 Description of Each Jurisdiction's Participation in the Planning Process 2-1
Section 3 Planning Process Documentation 3-1
3.1 Description of Planning Committee Formation 3-1
3.1.1 Invitation to Participate 3-1
3.2 Name of Planning Committee and its Members 3-1
3.3 Hazard Mitigation Working Group Meetings 3-3
3.4 Planning Process Milestones 3-3
3.5 Public Involvement 3-4
3.6 Existing Plans or Studies Reviewed 3-5
Section 4 Risk Assessment 4-1
4.1 Overview of the Risk Assessment Process 4-1
4.1.1 Identifying Hazards 4-2
4.1.2 Profiling Hazards 4-2
4.1.3 Identifying Assets 4-2
4.1.4 Assessing Vulnerability 4-3
4.1.5 Repetitive Loss 4-3
4.1.6 Analyzing Development Trends 4-3
4.2 Hazard Identification and Screening 4-3
4.2.1 List of Hazards Prevalent in the Jurisdiction 4-3
4.2.2 Hazard Identification Process 4-4
4.2.3 Hazard Identification Sources 4-7
4.2.4 Non-Profiled Hazards 4-7
4.3 Hazard Profiles 4-8
4.3.1 Coastal Storms, Erosion and Tsunami 4-9
4.3.2 Dam Failure 4-19
4.3.3 Earthquake 4-23
4.3.4 Flood 4-29
4.3.5 Rain-Induced Landslide 4-35
4.3.6 Liquefaction 4-39
4.3.7 Structure/Wildfire Fire 4-43
4.3.8 Manmade Hazards 4-49
4.4 Vulnerability Assessment 4-54
4.4.1 Asset Inventory 4-54
4.4.2 Estimating Potential Exposure and Losses, and Future Development
Trends 4-55
TABLE OF CONTENTS
4.5 Multi-Jurisdictional Assessment 4-102
4.5.1 Analysis of Land Use 4-102
4.5.2 Analysis of Development Trends 4-105
Section 5 Goals, Objectives and Actions 5-1
5.1 Overview 5-1
5.2 Regional Considerations 5-4
5.3 City of Carlsbad 5-5
5.3.1 Capabilities Assessment 5-6
5.3.2 Goals, Objectives and Actions 5-9
5.4 City of Chula Vista 5-17
5.4.1 Capabilities Assessment 5-19
5.4.2 Goals, Objectives and Actions 5-25
5.5 CityofCoronado 5-43
5.5.1 Capabilities Assessment 5-44
5.5.2 Goals, Objectives and Actions 5-47
5.6 City of Del Mar....; 5-55
5.6.1 Capabilities Assessment 5-56
5.6.2 Goals, Objectives and Actions 5-59
5.7 CityofElCajon 5-67
5.7.1 Capabilities Assessment 5-68
5.7.2 Goals, Objectives and Actions 5-71
5.8 CityofEncinitas 5-81
5.8.1 Capabilities Assessment 5-83
5.8.2 Goals, Objectives and Actions 5-86
5.9 CityofEscondido 5-103
5.9.1 Capability Assessment 5-104
5.9.2 Goals, Objectives and Actions 5-109
5.10 City of Imperial Beach 5-123
5.10.1 Capabilities Assessment 5-124
5.10.2 Goals, Objectives and Actions 5-128
5.11 City of La Mesa..". 5-141
5.11.1 Capabilities Assessment 5-142
5.11.2 Goals, Objectives and Actions 5-145
5.12 City of Lemon Grove 5-153
5.12.1 Capabilities Assessment 5-154
5.12.2 Goals, Objectives and Actions 5-157
5.13 City of National City 5-163
5.13.1 Capabilities Assessment 5-164
5.13.2 Goals, Objectives and Actions 5-167
5.14 City of Oceanside 5-179
5.14.1 Capabilities Assessment 5-180
5.14.2 Goals, Objectives and Actions 5-184
5.15 CityofPoway 5-191
5.15.2 Goals, Objectives and Actions 5-195
5.16 City of San Diego 5-201
5.16.1 Capabilities Assessment 5-202
5.16.2 Goals, Objectives and Actions 5-211
11
TABLE OF CONTENTS
5.17 City of San Marcos 5-219
5.17.1 Capabilities Assessment 5-220
5.17.2 Goals, Objectives and Actions 5-225
5.18 City of Santee 5-237
5.18.1 Capabilities Assessment 5-238
5.18.2 Goals, Objectives and Actions 5-242
5.19 City of Solana Beach 259
5.19.1 Capabilities Assessment 260
5.19.2 Goals, Objectives and Actions 263
5.20 City of Vista 5-271
5.20.1 Capabilities Assessment 5-272
5.20.2 Goals, Objectives and Actions 5-276
5.21 County of San Diego 5-285
5.21.1 Capabilities Assessment 5-287
5.21.2 Goals, Objectives and Actions 5-292
5.22 Rancho Santa Fe Fire Protection District 5-309
5.22.1 Capabilities Assessment 5-311
5.22.2 Goals, Objectives and Actions 5-316
Section 6 Plan Maintenance 6-1
6.1 Monitoring, Evaluating and Updating the Plan 6-1
6.1.1 Plan Monitoring 6-1
6.1.2 Plan Evaluation 6-1
6.1.3 Plan Updates 6-1
6.1.4 Implementation Through Existing Programs 6-2
6.1.5 Continued Public Involvement 6-2
Section 7 References 7-1
STAPLEE Criteria 1
STAPLES Criteria 3
STAPLEE Criteria 4
ill
list of Tables, Figures, and Appendices
Tables
Table 4.2-1 Summary of Hazard Identification Results
Table 4.3-1 Modified Mercalli Intensity Scale
Table 4.3-2 Historical Records of Large Floods in San Diego County
Table 4.3-3 Major Wildfires in San Diego County
Table 4.3-4 Licensed Hazardous Material Sites by Jurisdiction
Table 4.3-5 Toxic Chemical Reported Releases in San Diego County, California 2001
Table 4.4-1 Abbreviations and Costs Used for Critical Facilities and Infrastructure
Table 4.4-2 Inventory of Critical Facilities and Infrastructure and Exposure Value by Jurisdiction
Table 4.4-3 Inventory of Exposure for Infrastructure
Table 4.4-4 Inventory of the Maximum Population and Building Exposure by Jurisdiction
Table 4.4-5 Potential Exposure from Coastal Storm/Erosion Hazard by Jurisdiction
Table 4.4-6 Potential Exposure from Tsunami Hazard by Jurisdiction
Table 4.4-7 Potential Exposure to Critical Facilities and Infrastructure from Tsunami Hazard by
Jurisdiction
Table 4.4.8 Potential Exposure from Dam Inundation Hazard by Jurisdiction
Table 4.4-9 Potential Exposure to Critical Facilities and Infrastructure from Dam Inundation Hazard
by Jurisdiction
Table 4.4-10 Potential Exposure and Losses from Annualized Earthquake Hazard by Jurisdiction
Table 4.4-11 Potential Exposure to Critical Facilities and Infrastructure from 100-Year Earthquake
Hazard by Jurisdiction
Table 4.4-12 Potential Exposure to Critical Facilities and Infrastructure from 500-Year Earthquake
Hazard by Jurisdiction
Table 4.4-13 Potential Exposure and Losses from 100-Year Flood Hazard by Jurisdiction
Table 4.4-14 Potential Exposure to Critical Facilities and Infrastructure from 100-Year Flood Hazard
by Jurisdiction
Table 4.4-15 Potential Exposure and Losses from 500-Year Flood Hazard by Jurisdiction
Table 4.4-16 Potential Exposure to Critical Facilities and Infrastructure from 500-Year Flood Hazard
by Jurisdiction
Table 4.4-17 Potential Exposure from High Rain-Induced Landslide Hazard by Jurisdiction
Table 4.4-18 Potential Exposure to Critical Facilities and Infrastructure from High Rain-Induced
Landslide Hazard by Jurisdiction
Table 4.4-19 Potential Exposure to Moderate Rain-Induced Landslide Hazard by Jurisdiction
Table 4.4-20 Potential Exposure to Critical Facilities and Infrastructure from Moderate Rain-Induced
Landslide Hazard by Jurisdiction
Table 4.4-21 Potential Exposure from Extreme Wildfire Hazard by Jurisdiction
Table 4.4-22 Potential Exposure from Very High Wildfire Hazard by Jurisdiction
Table 4.4-23 Potential Exposure from High Wildfire Hazard by Jurisdiction
Table 4.4-24 Potential Exposure from Moderate Wildfire Hazard by Jurisdiction
Table 4.4-25 Potential Exposure from Wildfire (Moderate, High, Very High, Extreme Combined)
Hazard by Jurisdiction
Table 4.4-26 Potential Exposure to Critical Facilities and Infrastructures from Extreme Wildfire
Hazard by Jurisdiction
Table 4.4-27 Potential Exposure to Critical Facilities and Infrastructures from Very High Wildfire
Hazard by Jurisdiction
Table 4.4-28 Potential Exposure to Critical Facilities and Infrastructures from High Wildfire Hazard
by Jurisdiction
IV
List of Tables, figures, and Appendices
Table 4.4-29 Potential Exposure to Critical Facilities and Infrastructures from Moderate Wildfire
Hazard by Jurisdiction
Table 4.4-30 Potential Exposure to Critical Facilities and Infrastructures from (Moderate, High, Very
High, Extreme Combined) Wildfire Hazard by Jurisdiction
Table 5.3-1 Summary of Potential Hazard-Related Exposure/Loss in Carlsbad
Table 5.3-2 City of Carlsbad: Administrative and Technical Capacity
Table 5.3-3 City of Carlsbad: Legal and Regulatory Capability
Table 5.3-4 City of Carlsbad: Fiscal Capability
Table 5.4-1 Summary of Potential Hazard-Related Exposure/Loss in Chula Vista
Table 5.4-2 City of Chula Vista: Administrative and Technical Capacity
Table 5.4-3 City of Chula Vista: Legal and Regulatory Capability
Table 5.4-4 City of Chula Vista: Fiscal Capability
Table 5.5-1 Summary of Potential Hazard-Related Exposure/Loss in Coronado
Table 5.5-2 City of Coronado: Administrative and Technical Capacity
Table 5.5-3 City of Coronado: Legal and Regulatory Capability
Table 5.5-4 City of Coronado: Fiscal Capability
Table 5.6-1 Summary of Potential Hazard-Related Exposure/Loss in Del Mar
Table 5.6-2 City of Del Mar: Administrative and Technical Capacity
Table 5.6-3 City of Del Mar: Legal and Regulatory Capability
Table 5.6-4 City of Del Mar: Fiscal Capability
Table 5.7-1 Summary of Potential Hazard-Related Exposure/Loss in El Cajon
Table 5.7-2 City of El Cajon: Administrative and Technical Capacity
Table 5.7-3 City of El Cajon: Legal and Regulatory Capability
Table 5.7-4 City of El Cajon: Fiscal Capability
Table 5.8-1 Summary of Potential Hazard-Related Exposure/Loss in Encinitas
Table 5.8-2 City of Encinitas: Administrative and Technical Capacity
Table 5.8-3 City of Encinitas: Legal and Regulatory Capability
Table 5.8-4 City of Encinitas: Fiscal Capability
Table 5.9-1 Summary of Potential Hazard-Related Exposure/Loss in Escondido
Table 5.9-2 City of Escondido: Administrative and Technical Capacity
Table 5.9-3 City of Escondido: Legal and Regulatory Capability
Table 5.9-4 City of Escondido: Fiscal Capability
Table 5.10-1 Summary of Potential Hazard-Related Exposure/Loss in Imperial Beach
Table 5.10-2 City of Imperial Beach: Administrative and Technical Capacity
Table 5.10-3 City of Imperial Beach: Legal and Regulatory Capability
Table 5.10-4 City of Imperial Beach: Fiscal Capability
Table 5-11-1 Summary of Potential Hazard-Related Exposure/Loss in La Mesa
Table 5.11-2 City of La Mesa: Administrative and Technical Capacity
Table 5.11-3 City of La Mesa: Legal and Regulatory Capability
Table 5.11-4 City of La Mesa: Fiscal Capability
Table 5.12-1 Summary of Potential Hazard-Related Exposure/Loss in Lemon Grove
Table 5.12-2 City of Lemon Grove: Administrative and Technical Capacity
Table 5.12-3 City of Lemon Grove: Legal and Regulatory Capability
Table 5.12-4 City of Lemon Grove: Fiscal Capability
Table 5.13-1 Summary of Potential Hazard-Related Exposure/Loss in National City
Table 5.13-2 City of National City: Administrative and Technical Capacity
Table 5.13-3 City of National City: Legal and Regulatory Capability
Table 5.13-4 City of National City: Fiscal Capability
Table 5.14-1 Summary of Potential Hazard-Related Exposure/Loss in Oceanside
List of Tables, Figures, and Appendices
Table 5. 14-2
Table 5. 14-3
Table 5. 14-4
Table 5.15-1
Table 5. 15-2
Table 5. 15-3
Table 5. 15-4
Table 5. 16-1
Table 5. 16-2
Table 5. 16-3
Table 5. 16-4
Table 5. 17-1
Table 5. 17-2
Table 5. 17-3
Table 5. 17-4
Table 5. 18-1
Table 5. 18-2
Table 5. 18-3
Table 5. 18-4
Table 5. 19-1
Table 5. 19-2
Table 5. 19-3
Table 5. 19-4
Table 5. 20-1
Table 5. 20-2
Table 5. 20-3
Table 5. 20-4
Table 5.21-la
Table 5.2 1-lb
Table 5. 2 1-2
Table 5. 2 1-3
Table 5. 2 1-4
Table 5. 22-1
Table. 5. 22-2
Table 5. 22-3
Table 5. 22-4
Figures
Figure 4.3.1
Figure 4.3 .2
Figure 4.3.3
Figure 4.3.4
Figure 4.3.5
Figure 4.3.6
Figure 4.3 .7
Figure 4.4.1
Figure 4.5.1
City of Oceanside: Administrative and Technical Capacity
City of Oceanside: Legal and Regulatory Capability
City of Oceanside: Fiscal Capability
Summary of Potential Hazard-Related Exposure/Loss in Poway
City of Poway: Administrative and Technical Capacity
City of Poway: Legal and Regulatory Capability
City of Poway: Fiscal Capability
Summary of Potential Hazard-Related Exposure/Loss in San Diego
City of San Diego: Administrative and Technical Capacity
City of San Diego: Legal and Regulatory Capability
City of San Diego: Fiscal Capability
Summary of Potential Hazard-Related Exposure/Loss in San Marcos
City of San Marcos: Administrative and Technical Capacity
City of San Marcos: Legal and Regulatory Capability
City of San Marcos: Fiscal Capability
Summary of Potential Hazard-Related Exposure/Loss in Santee
City of Santee: Administrative and Technical Capacity
City of Santee: Legal and Regulatory Capability
City of Santee: Fiscal Capability
Summary of Potential Hazard-Related Exposure/Loss in Solana Beach
City of Solana Beach: Administrative and Technical Capacity
City of Solana Beach: Legal and Regulatory Capability
City of Solana Beach: Fiscal Capability
Summary of Potential Hazard-Related Exposure/Loss in Vista
City of Vista: Administrative and Technical Capacity
City of Vista: Legal and Regulatory Capability
City of Vista: Fiscal Capability
Summary of Potential Hazard-Related Exposure/Loss in the County (Urban)
Summary of Potential Hazard-Related Exposure/Loss in the County (Rural)
County of San Diego: Administrative and Technical Capacity
County of San Diego: Legal and Regulatory Capability
County of San Diego: Fiscal Capability
Summary of Potential Hazard-Related Exposure/Loss in Rancho Santa
Rancho Santa Fe FPD: Administrative and Technical Capacity
Rancho Santa Fe FPD: Legal and Regulatory Capability
Rancho Santa Fe FPD: Fiscal Capability
Hazard Profile: Coastal Storms/Erosion/Tsunami
Hazard Profile: Dam Failure
Hazard Profile: Earthquake
Hazard Profile: Flood
Hazard Profile: Rain-Induced Landslide
Hazard Profile: Liquefaction
Hazard Profile: Structure
Critical Facilities in San Diego County
Land Use in San Diego County
FeFPD
VI
List of Tables, Figures, and Appendices
Figure 4.5.2 Population Growth
Appendices
Appendix A HMWG/Public Meeting Information
Appendix B Data Matrix
Appendix C Letters of Participation
Appendix D Implementation Status
Attachment
Attachment A Human Caused Hazards (Separately Bound)
vn
List of Tables, Figures, and Appendices
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Vlll
List of Acronyms and Abbreviations
AIR
AMSA
APN
ATAC
BRDG
BRS
BUS
Cal-ARP
CAMEO
Carlsbad
CAS
CCR
CCTV
CERT
CGC
Chula Vista
CEQA
COM
Coronado
CUPA
DEH
Del Mar
El Cajon
ELEC
EMER
Encinitas
EOC
Escondido
FPD
GOVT
HIRT
HMD
CIS
HMMU
HMWG
HOSP
HWY
IDLH
Imperial Beach
INFR
JPA
La Mesa
Lemon Grove
LOG
LPG
Airport facilities
Association of Metropolitan Sewerage Agencies
Assessor Parcel Number
Anti-Terrorism Advisory Council
Bridges
Base Release Scenario
Bus facilities
California Accidental Release Program
Computer-Aided Management of Emergency Operations
City of Carlsbad
California Code of Regulations
Closed Circuit Television
Community Emergency Response Team
California Government Code
City of Chula Vista
California Environmental Quality Act
Communication facilities and utilities
City of Coronado
Certified Unified Program Agency
Department of Environmental Health
City of Del Mar
City of El Cajon
Electric Power facility
Emergency Centers, Fire Stations and Police Stations
City of Encinitas
Emergency Operations Center
City of Escondido
Fire Protection District
Government Office/Civic Center
Hazardous Incident Response Team
Hazardous Materials Division
Geographic Information Systems
Hazardous Materials Management Unit
Hazard Mitigation Working Group
Hospitals/Care facilities
Highway
Immediately Dangerous to Life and Health
City of Imperial Beach
Kilometers of Infrastructure. Includes:
City of La Mesa
City of Lemon Grove
Level of Concern
Local Planning Group
IX
List of Acronyms and Abbreviations
MMST
National City
NOAA
OCA
Oceanside
og
PAG
Plan
PORT
POT
Poway
PSI
RAIL
RMP
RS
RSFFPD
RTR
SANDAG
San Diego
San Marcos
SCADA
SCH
SDUASS
SERP
Solana Beach
SONGS
TAG
TQ
UDC
Unincorporated County
USEPA
Vista
Metropolitan Medical Strike Team
City of National City
National Oceanic and Atmospheric Administration
Offsite Consequence Analysis
City of Oceanside
Oil/Gas Pipelines
Protective Action Guidelines
San Diego Multi-Jurisdictional Multi-Hazard Mitigation Plan
Port facilities
Potable and Waste Water facilities
City of Poway
pound per square inch
Rail facilities
Risk Management Program
Regulated Substance
Rancho Santa Fe Fire Protection District
Railroad Tracks
San Diego Association of Governments
City of San Diego
City of San Marcos
Supervisor}' Control and Data Acquisition
Schools
San Diego Urban Area Security Strategy
Site Emergency Response Plans
City of Solana Beach
San Onofre Nuclear Generating Station
Target Assessment Group
Threshold Quantity
Unified Disaster Council
County of San Diego
United States Environmental Protection Agency
City of Vista
SECTIONONE Introduction
SECTION 1 INTRODUCTION
Across the United States, natural and manmade disasters have led to increasing levels of death,
injury, property damage, and interruption of business and government services. The impact on
families and individuals can be immense and damages to businesses can result in regional
economic consequences. The time, money and effort to respond to and recover from these
disasters divert public resources and attention from other important programs and problems. With
four presidential disaster declarations, three gubernatorial proclamations and thirteen local
proclamations of emergency since 1999 San Diego County, California recognizes the
consequences of disasters and the need to reduce the impacts of natural and manmade hazards.
The elected and appointed officials of the County also know that with careful selection,
mitigation actions in the form of projects and programs can become long-term, cost effective
means for reducing the impact of natural and manmade hazards.
This Multi-Hazard Mitigation Plan for San Diego County, California (the PlanJ, was prepared
with input from county residents, responsible officials, the San Diego County Water Authority,
the Rancho Santa Fe Fire Protection District, the California Emergency Management Agency
(Cal EM A) and the Federal Emergency Management Agency (FEMA). The process to develop
the Plan included nearly a year of coordination with representatives from all of the jurisdictions in
the region. The Plan will guide the County toward greater disaster resistance in harmony with the
character and needs of the community.
This section of the Plan includes an overview of the Plan, a discussion of the Plan's purpose and
authority, and a description of the 18 incorporated cities and the unincorporated County within
the San Diego region.
1.1 PLAN DESCRIPTION/PURPOSE OF PLAN
Federal legislation has historically provided funding for disaster relief, recovery, and some hazard
mitigation planning. The Disaster Mitigation Act of 2000 (DMA 2000) is the latest legislation to
improve this planning process (Public Law 106-390). The new legislation reinforces the
importance of mitigation planning and emphasizes planning for disasters before they occur. As
such, DMA 2000 establishes a pre-disaster hazard mitigation program and new requirements for
the national post-disaster Hazard Mitigation Grant Program (HMGP).
Section 322 of DMA 2000 specifically addresses mitigation planning at the state and local levels.
It identifies new requirements that allow HMGP funds to be used for planning activities, and
increases the amount of HMGP funds available to states that have developed a comprehensive,
enhanced mitigation plan prior to a disaster. States and communities must have an approved
mitigation plan in place prior to receiving post-disaster HMGP funds. Local and tribal mitigation
plans must demonstrate that their proposed mitigation measures are based on a sound planning
process that accounts for the risk to and the capabilities of the individual communities.
State governments have certain responsibilities for implementing Section 322, including:
Preparing and submitting a standard or enhanced state mitigation plan;
1-1
SECTIONOM Introduction
Reviewing and updating the state mitigation plan every three years;
Providing technical assistance and training to local governments to assist them in applying for
HMGP grants and in developing local mitigation plans; and
Reviewing and approving local plans if the state is designated a managing state and has an
approved enhanced plan.
DMA 2000 is intended to facilitate cooperation between state and local authorities, prompting
them to work together. It encourages and rewards local and state pre-disaster planning and
promotes sustainability as a strategy for disaster resistance. This enhanced planning network is
intended to enable local and state governments to articulate accurate needs for mitigation,
resulting in faster allocation of funding and more effective risk reduction projects.
FEMA prepared an Interim Final Rule, published in the Federal Register on February 26, 2002
(44 CFR Parts 201 and 206), which establishes planning and funding criteria for states and local
communities.
The Plan has been prepared to meet FEMA and COESS requirements thus making the County
eligible for funding and technical assistance from state and federal hazard mitigation programs.
1.2 PLAN PURPOSE AND AUTHORITY
In the early 1960s, the incorporated cities and the County of San Diego formed a Joint Powers
Agreement which established the Unified San Diego County Emergency Services Organization
(USDCESO) and the Unified Disaster Council (UDC) as the policy making group. The UDC, the
San Diego County Board of Supervisors and City Councils from each participating municipality
are required to adopt the Plan prior to its submittal to COESS and FEMA for final approval.
The Plan is intended to serve many purposes, including:
Enhance Public Awareness and Understanding - to help residents of the County better
understand the natural and manmade hazards that threaten public health, safety, and
welfare; economic vitality; and the operational capability of important institutions;
Create a Decision Tool for Management - to provide information that managers and leaders
of local government, business and industry, community associations, and other key
institutions and organizations need to take action to address vulnerabilities to future
disasters;
Promote Compliance with State and Federal Program Requirements - to insure that San
Diego County and its incorporated cities can take full advantage of state and federal grant
programs, policies, and regulations that encourage or mandate that local governments
develop comprehensive hazard mitigation plans;
Enhance Local Policies for Hazard Mitigation Capability - to provide the policy basis for
mitigation actions that should be promulgated by participating jurisdictions to create a
more disaster-resistant future: and
1-2
SEBTIONONE introduction
Provide Inter-Jurisdictional Coordination of Mitigation-Related Programming — to ensure
that proposals for mitigation initiatives are reviewed and coordinated among the
participating jurisdictions within the County.
Achieve Regulatory Compliance - To qualify for certain forms of federal aid for pre- and
post-disaster funding, local jurisdictions must comply with the federal DMA 2000 and its
implementing regulations (44 CFR Section 201.6). DMA 2000 intends for hazard
mitigation plans to remain relevant and current. Therefore, it requires that State hazard
mitigation plans are updated every three years and local plans, including San Diego
County's, every five years. This means that the Hazard Mitigation Plan for San Diego
County uses a "five-year planning horizon". It is designed to carry the County through
the next five years, after which its assumptions, goals, and objectives will be revisited
and the plan resubmitted for approval.
1.3 COMMUNITY DESCRIPTION
1.3.1 The County of San Diego
San Diego County, one of 58 counties in the State of California, was established on February 18,
1850, just after California became the 31st state. The County stretches 65 miles from north to
south, and 86 miles from east to west, covering 4,261 square miles. Elevation ranges from sea
level to about 6,500 feet. Orange and Riverside Counties border it to the north, the agricultural
communities of Imperial County to the east, the Pacific Ocean to the west, and the State of Baja
California, Mexico to the south. Geographically, the County is on the same approximate latitude
as Dallas, Texas and Charleston, South Carolina.
San Diego County is comprised of 18 incorporated cities and 17 unincorporated communities.
The county's total population in 2009 was approximately 3.17 million with a median age of 35
years (California Department of Finance Report E-l: City/County Population Estimates). San
Diego is the third most populous county in the state.
The following subsections provide an overview of the Economy, Physical Features,
Infrastructure, and Jurisdictional Summaries for the County of San Diego.
1.3.1.1 Economy
San Diego offers a vibrant and diverse economy along with a strong and committed public/private
partnership of local government and businesses dedicated to the creation and retention of quality
jobs for its residents. Although slowed by the recession and defense cuts in the late 1980's and
early 1990's, the business climate continues to thrive due to the diversification of valuable assets
such as world class research institutions; proximity to Mexico and the Pacific Rim; a well
educated, highly productive work force; and an unmatched entrepreneurial spirit.
According to the San Diego Association of Governments (SanDAG), San Diego's Gross Regional
Product (GRP)-an estimate of the total output of goods and services in the county-was estimated
to reach $170.4 billion in 2008, and was forecast to increase 5.4% to $179.6 billion in 2009. The
forecast for the consumer price index showed inflation increasing slightly to 1.8% in 2009.
1-3
SEBTIOHONE Introduction
San Diego's abundant and diverse supply of labor at competitive rates is one of the area's greatest
assets. As of August 2009, the total civilian labor force was estimated at 1.58 million, which
includes self-employed individuals and wage and salary employment. Unemployment for 2008
was 10.3% or 162,400 persons. This is higher than the national rate of 10.0% but significantly
lower than the state's rate of 12.3% (Source: Bureau of Labor Statistics)
There are several reasons for the strong labor supply in San Diego. The area's appealing climate
and renowned quality of life are two main factors that attract a quality workforce. The excellent
quality of life continues to be an important advantage for San Diego companies in attracting and
retaining workers. In addition, local colleges and universities augment the region's steady influx
of qualified labor. Each year San Diego's educational institutions graduate approximately 1,500
students with bachelors, masters and PhD degrees in electrical engineering, computer science,
information systems, mechanical engineering and electronic technology. Over 2,500 students
annually receive advanced degrees in business administration. There is also a pool of qualified
workers from San Diego's business schools, which annually graduate over 1,000 students with
administrative and data processing skills.
1.3.1.2 Employment
San Diego's diverse and thriving high-tech industry has become the fastest growing sector of
employment and a large driving force behind the region's continued economic prosperity. San
Diego's high-tech industry comprises over a tenth of the region's total economic output.
San Diego boasts the third largest concentration of biotech companies in the country with an
estimated 400 firms. Currently there are over 32,000 people employed in San Diego's biotech
industry. San Diego boasts the highest dollar amount of National Institute for Health grants per
capita in the nation. Local biotech firms produce 9% of all drug sales and revenues in the United
States. San Diego-based companies currently have over 25 commercial products on the market
and approximately 75 products in late-phase clinical trials. The general services industry is the
second largest employment sector in the County, totaling nearly 30% of the county's industry
employment. This sector includes business services, San Diego's tourism industry, health services
and various business services, employing 421,900 workers. Government is the fourth largest
employer with 203,900 jobs accounting for about 15% of total industry employment. The state
and local government is the largest employer with over 160,000 employees.
1.3.1.3 Physical Features
The physical, social and economic development of the region has been influenced by its unique
geography, which encompasses over 70 miles of coastline, broad valleys, lakes, forested
mountains and the desert. The county can be divided into three basic geographic areas, all
generally running in the north-south direction. The coastal plain extends from the ocean to inland
areas for 20 to 25 miles. The foothills and mountains, rising in elevation to 6,500 feet, comprise
the middle section of the county. The third area is the desert, extending from the mountains into
Imperial County, 80 miles east of the coast. San Diegans can live in the mountains, work near the
ocean, and take recreational day trips to the desert.
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One of San Diego's greatest assets is its climate. With an average yearly temperature of 70
degrees, the local climate has mild winters, pleasant summers, and an abundance of sunshine and
light rainfall.
San Diego County experiences climatic diversity due to its varied topography. Traveling inland,
temperatures tend to be warmer in the summer and cooler in the winter. In the local mountains,
the average daily highs are 77 degrees and lows are about 45 degrees. The mountains get a light
snowfall several times a year. East of the mountains is the Anza Borrego Desert, where rainfall is
minimal and the summers are hot. The dry, mild climate of San Diego County is conducive to
productivity. Outdoor work and recreational activities are possible almost all year-round. In
addition, storage and indoor work can be handled with minimum investment in heating and air
conditioning.
1.3.1.4 Infrastructure
San Diego has a well-developed highway system. There are about 600 miles of state highways
and 300 miles of freeways and expressways within the San Diego region. The county also
encompasses more than 7,185 miles of maintained city streets and county roads. Roughly 11.6
million vehicle trips are made on the region's roadways daily, accounting for more than 68
million vehicle miles traveled daily.
Since 1980, San Diego's licensed drivers have increased 46%; likewise, auto registrations have
increased 57%. Vehicle miles of travel (VMT) are up 86% since 1980. Unfortunately the increase
in drivers, vehicles and VMT has not been matched by corresponding increases in freeway
mileage (10%) or local street and road mileage (19%). Over the same time period, there has been
a decrease in both reported fatal accidents and injury accidents.
All urbanized areas in the region and some rural areas are served by public transit. The San Diego
Region is divided into two transit development boards: the San Diego Metropolitan Transit
Development Board (MTDB), and the North County Transit Development Board (NCTD). San
Diego Transit Corporation (SDTC), which operates transit service under MTDB, serves about
two million people annually with routes that cover the cities of San Diego, Chula Vista, El Cajon,
La Mesa and National City, as well as portions of San Diego County's unincorporated areas.
SDTC routes also connect with other regional operators' routes. San Diego Trolley operates the
light rail transit system under MTDB. The North County Transit District (NCTD) buses carry
passengers in north San Diego County, including Del Mar, east to Escondido, north to Orange
County and Riverside County, and north to Camp Pendleton. NCTD's bus fleet carries more than
11 million passengers every year. NCTD's bus system has 35 routes. In addition, NCTD runs
special Express Buses for certain sporting and special events in San Diego.
San Diego Gas & Electric is a public utility that provides natural gas and electric service to 3
million consumers through 1.2 million electric meters and 720,000 natural gas meters in San
Diego and southern Orange counties. SDG&E's service area encompasses 4,100 square miles,
covering two counties and 25 cities. SDG&E is a subsidiary of Sempra Energy, a Fortune 500
energy services holding company based in San Diego. Virtually all of the petroleum products in
the region are delivered via a pipeline system operated by Kinder Morgan Energy Partners.
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SECTIONONE Introduction
The San Diego County Water Authority is a public agency serving the San Diego region as a
wholesale supplier of water. The Water Authority works through its 24 member agencies to
provide a safe, reliable water supply to support the region's $171 billion economy and the quality
of life of 3 million residents or 90 percent of the county's population. The 24 member agencies
are comprised of six cities, five water districts, three irrigation districts, eight municipal water
districts, one public utility district and one federal agency (military base) and cover a service area
of 920,000 acres. In 2008, Metropolitan Water District of Southern California supplied 71% of
the water while 29% came from local and other supplies. Metropolitan imports the water from
two sources, the Colorado River and the state Water Project (Bay-Delta) in northern California.
Traveling hundreds of miles over aqueduct systems that include pump stations, treatment plants
and reservoirs, approximately 700,000 acre-feet of water is transported annually through the
Water Authority's five pipelines and then distributed to the member agencies for delivery to the
public. Residents place the highest demand on water, consuming roughly 59% of all water in San
Diego County. Industrial/commercial use is the second largest consumer of water at 17%,
followed by the public sector at 13% and agriculture at 12% of the total water demand.
1.3.2 Local Jurisdictions
1.3.2.1 Carlsbad (Population: 103 Jll)
Carlsbad is a coastal community located 35 miles north of downtown San Diego. It is bordered by
Encinitas to the south, Vista and San Marcos to the east and Oceanside to the north. Carlsbad is
home to world-class resorts such as the La Costa Resort and Spa and the Four Seasons Resort at
Aviara, offering championship-level golf and tennis facilities. The newest addition to Carlsbad's
commercial/recreational landscape is Legoland, which opened in Spring 1999. The city of
Carlsbad has a strong economy, much of which has come from industrial development. Callaway
Golf, Cobra Golf, ISIS Pharmaceuticals, Mallinckrodt Medical, NTN Communications and
Immune Response are just a few of the local companies located in Carlsbad. The area has nine
elementary schools, two junior high schools, and three high schools. The school district ranks
among the best in the county. Distinguished private and parochial schools also serve Carlsbad,
including the internationally renowned Army Navy Academy.
1.3.2.2 Chula Vista (Population: 231J05)
Chula Vista is home to an estimated 44% of all businesses in the South Bay Region of San Diego
County. Chula Vista is the second largest municipality in San Diego County, and the 21st largest
of 450 California cities. Today Chula Vista is attracting such companies as Solar Turbines and
Raytheon, a $20 billion global technology firm serving the defense industry. Chula Vista ranks
among the nation's top ten governments in terms of employee productivity and local debt levels.
1.3.2.3 Coronado (Population: 23J01)
Coronado is a 13.5 square mile ocean village. The military bases of the Naval Air Station North
Island and Naval Amphibious Base occupy 5.3 square miles. Coronado is connected to San Diego
by a 2.3-mile bridge and to Imperial Beach (its neighbor to the south), by a six-mile scenic
highway, the Silver Strand. It is primarily a bedroom community for San Diego executives, a
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SECTIONONE Introduction
haven for retired senior military officers and an internationally renowned tourist destination. This
vibrant community welcomes more than two million visitors annually to soak up the sun and the
sand while enjoying the lush surroundings and village appeal of Coronado. The city contains 14
hotels, amongst them are 3 world-class resorts including the Hotel Del Coronado and 67 highly
acclaimed restaurants.
1.3.2.4 Del Mar (Population: 4J80)
Del Mar is the smallest city in the County with only 4,580 residents in the year 2000. Located 27
miles north of downtown San Diego, this coastal community is known for its affluence and
comfortable standard of living. It is a beautiful wooded hillside area overlooking the ocean and
has a resort-like atmosphere. The Del Mar Racetrack and Thoroughbred Club serve as Del Mar's
most noted landmark. This racetrack is also the location for the annual San Diego County Fair.
The City of Del Mai- has 2.9 miles of shoreline that include the Del Mar City Beach and the
Torrey Pines State Beach. There are two elementary schools, one junior high school and one high
school in Del Mar, which is considered one of the regions best school districts.
13.2.5 El Cajon (Population: 97J34)
El Cajon is located 15 miles east of the City of San Diego. El Cajon is an inland valley
surrounded by rolling hills and mountains. El Cajon's current population of 97,934 makes it the
sixth most populated jurisdiction in the region. As one of the most eastern cities in the County, El
Cajon has a warm and dry climate. El Cajon is a diverse residential, commercial, and industrial
area, and serves as the main commerce center for several surrounding communities. Gillespie
Field, a general aviation airport, is a major contributing factor to the city's vibrant industrial
development. El Cajon includes a cross-section of housing types from lower cost mobile homes
and apartments to moderately priced condominiums to higher cost single-family residences.
There are 23 elementary schools, seven middle schools and four high schools.
1.3.2.6 Encinitas (Population: 64J45)
Encinitas is located along six miles of Pacific coastline in the northern half of San Diego County.
Approximately 21 square miles, Encinitas is characterized by coastal beaches, cliffs, flat topped
coastal areas, steep mesa bluffs and rolling hills. Incorporated in 1986, the City encompasses the
communities of Old Encinitas, New Encinitas, Olivenhain, Leucadia and Cardiff-By-The-Sea.
The Los Angeles/San Diego (LOSSAN) rail passes through the city, and other transit corridors
traversing the city include El Camino Real and Coast Highway 101. Encinitas is bordered by
Carlsbad to the north, Solana Beach to the south and the community of Rancho Santa Fe to the
east.
13.2.7 Escondido (Population: 143 J89)
Escondido has a reputation as a bedroom community due to the large percentage of residents who
work outside of the city. Escondido is located 30 miles north of San Diego and is approximately
18 miles inland from the coast. It is the region's fifth most populated city. More than a decade
ago, the people of Escondido conceived a vision of cultural excellence. Today, the $73.4 million
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SECTIONONE Introduction
California Center for the Arts stands as a product of this vision. Escondido has 18 elementary
schools, nine of which are parochial schools, three middle schools and six high schools, three of
which are parochial. There is a unique mix of agriculture, industrial firms, high-tech firms,
recreational centers and parks, as well as residential areas. The areas largest shopping mall, the
North County Fair, houses 6 major retail stores and approximately 175 smaller stores. California
State University, San Marcos and Palomar Community College are located within minutes of
Escondido.
1.3.2.8 Imperial Beach (Population: 28^00)
Imperial Beach claims the distinction of being the "Most Southwesterly City - in the continental
United States." The City is located in the Southwest corner of San Diego County, only five miles
from the Mexican Border and 15 miles from downtown San Diego. With a population of 28,200,
Imperial Beach occupies an area of 4.4 square miles. Imperial Beach offers some of the least
expensive housing to be found west of the 1-5. It is primarily a resort/recreation community with
a vast beach area as well as a 12,000-foot pier for fishing. Some describe Imperial Beach as
quaint, but mostly the town has a rare innocence and a relaxed atmosphere. Looking south just
across the International border, Tijuana's famous "Bullring by the Sea," the Plaza De Monumental
can be seen.
1.3.2.9 La Mesa (Population: 56,666)
La Mesa is centrally located 12 miles east of downtown San Diego. La Mesa is a suburban
residential community as well as a commercial and trade center. The area is characterized by
rolling hills and has a large number of hilltop home sites that take advantage of the beautiful
views. La Mesa offers affordable housing within a wide range of prices, as well as high-end
luxury homes atop Mt. Helix. La Mesa has an abundance of mixed-use condominiums for those
who prefer a downtown village atmosphere. There is a positive balance between single-family
housing and multi-family housing within La Mesa's city limits. One of the region's major retail
facilities, Grossmont Center is located in the heart of the city adjacent to another major activity
center, Grossmont Hospital. The La Mesa-Spring Valley Elementary School District provides 18
elementary schools and four junior high schools. There are two high schools in the area and
Grossmont College, a two-year community college, is also located in La Mesa.
1.3.2.10 Lemon Grove Population: (25,611)
Lemon Grove lies eight miles east of downtown San Diego. Lemon Grove is the third smallest
jurisdiction in the San Diego region based on population and geographic size. Initially the site of
expansive lemon orchards, the city still remains a small town with a rural ambiance. Currently
manufacturing and trade account for over one-third of the total employment in this area. A
substantial proportion of the homes in Lemon Grove are single-family dwellings with the addition
of several apartments and condominiums built over the last 20 years. There are five elementary
schools and two junior high schools.
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SEBTIONONE introduction
1.3.2.11 National City (Population: 61J94)
National City is one of the county's oldest incorporated areas. Just five miles south of San Diego,
National City is the South Bay's center of industrial activity. The economy is based on
manufacturing, shipbuilding and repair. The San Diego Naval Station, which overlaps San Diego
and National City is the largest naval facility in the country. There are a great number of
historical sites in National City and homes in the area are usually 50 years or older. Stately
Victorians reflect the early part of the century when shipping and import/export magnates lived
here. Served by National Elementary and Sweetwater High School districts, National City also
offers several private schools for all grade levels. National City is best known for its Mile of Cars;
the title describing its abundant auto dealerships. Two large shopping malls, Plaza Bonita and
South Bay Plaza, are located in National City.
1.3.2.12 Oceanside (Population: 178^06)
Oceanside is centrally located between San Diego and Los Angeles. Located just 36 miles north
of downtown San Diego, Oceanside is bordered by Camp Pendleton to the north, Carlsbad to the
south, Vista to the east and the ocean to the west. The current population of 178,806 makes
Oceanside the fourth largest jurisdiction in the County and the largest coastal community.
Industrial real estate rates tend to be lower than the County average. There is an abundant supply
of new housing and condominium developments, which tend to be more affordable than in other
areas of Southern California coastal cities. With a near-perfect year-round climate and
recognition as one of the most livable places in the nation, Oceanside offers both an incomparable
lifestyle and abundant economic opportunity. Its extensive recreational facilities include 3.5 miles
of sandy beaches, the Oceanside Harbor and the Oceanside Lagoon. There are 16 elementary
schools, two parochial and two private, three middle schools and three high schools, as well as
Mira Costa College and the United States International University.
1.3.2.13 Poway (Population: 51,013)
Poway is located 23 miles northeast of San Diego within the well-populated 1-15 corridor. Poway
is distinct because it is set into the foothills. Poway's main recreational facility is the 350-acre
Lake Poway Park; the Lake also serves as a reservoir for the water supplied to San Diego by the
Colorado River Aqueduct. The area has many recreational facilities, providing complete park
sites, trails and fishing opportunities. Poway is also home to the Blue Sky Ecological Reserve,
700 acres of natural habitat with hiking, horseback riding and interpretive trails. The Poway
Performing Arts Center is an 815 seat professional theater that began its eleventh season in 2001.
The Poway Unified School District is excellent and has been consistently rated in the top tier. The
district has four high schools, five middle schools and 19 elementary schools. There are eight
private and parochial schools offering instruction from K-8 grades.
1.3.2.14 San Diego (Population 1J36£65)
The City of San Diego is the largest city in San Diego County, containing roughly half of the
County's total population. With its current population of 1,336,865, the City of San Diego is the
second largest city in the state. It is the region's economic hub, with well over half of the region's
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SECTIONONE Introduction
jobs and nearly three-quarters of the region's large employers. Thirteen of the region's 20 major
colleges and universities are in the City of San Diego, as are six of the region's major retail
centers. The City's visitor attractions are world-class and include Balboa Park, San Diego Zoo,
Wild Animal Park, Sea World, Cabrillo National Monument and Old Town State Historic Park.
The City of San Diego spans approximately 40 miles from its northern tip to the southern border.
Including the shoreline around the bays and lagoons, the City of San Diego borders a majority of
the region's shoreline, encompassing 93 of the region's 182 shoreline miles.
1.3.2.15 San Marcos (Population: 82,743)
San Marcos is located between Vista and Escondido, approximately 30 miles north of downtown
San Diego. San Marcos is known for its resort climate, rural setting, central location and
affordable housing prices. San Marcos has been the fasted growing jurisdiction in the region since
1956. It is home to two of the region's major educational facilities, Palomar Community College
and California State University, San Marcos. The K-12 School District is an award winning
district with over seven Schools of Distinction Awards to their credit.
13.2.16 Santee (Population: 56,068)
Santee lies 18 miles northeast of downtown San Diego and is bordered on the east and west by
slopes and rugged mountains. The San Diego River runs through this community, which was
once a dairy farming area. It is now a residential area that has experienced phenomenal growth
since the 1970's. Since the expansion of the San Diego Trolley, Santee residents can ride the
Trolley to Mission Valley, Downtown San Diego and as far as the U.S./Mexico Border.
Elementary students attend one of 11 elementary schools, while high school students attend
Santana or West Hills High School.
1.3.2.17 Solana Beach (Population: 14350)
As one of the county's most attractive coastal communities, Solana Beach is known for its small-
town atmosphere and pristine beaches. Incorporated in 1986, it has one of the highest median
income levels in the County as well as an outstanding school system recognized with state and
national awards of excellence. Lomas Santa Fe, located east of the freeway, is a master planned
community, which features shopping, homes, and condominiums, two golf courses and the family
oriented Lomas Santa Fe Country Club.
13.2.18 Vista (Population: 95,770)
Vista has been growing at twice the rate of the State of California and 50% faster than the rest of
the San Diego area in the last decade. There are 10 elementary schools, four middle schools, and
five high schools. More than 400 companies have located their businesses in the city since 1986.
13.2.19 Unincorporated County of San Diego (Population: 491,764)
The unincorporated County consists of approximately 34 Community Planning and Sub-regional
Areas. Many of the communities in the Unincorporated County jurisdiction are located in the
mountains, desert, North County, or on the border of Mexico. Rancho Santa Fe, an affluent
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SECTIBNONE Introduction
residential and resort community, is one of the exceptions, located within the urban core area.
The community of Julian is located in the central mountains along a principle travel route
between the desert and Metropolitan San Diego, and is a common tourist destination. Alpine is
located east of El Cajon on Interstate 8 and is considered a gateway to San Diego County's
wilderness areas of mountains, forests, and deserts.
The Sub-regional Planning Areas are Central Mountain, County Islands, Mountain Empire, North
County Metro, and North Mountain. Communities within the Central Mountain Sub-region are
Cuyamaca, Descanso, Guatay, Pine Valley, and Mount Laguna. The County Islands Community
Plan area consists of Mira Mesa, Greenwood, and Lincoln Acres. The North Mountain Sub-
region is mostly rural and includes Santa Ysabel, Warner Springs, Palomar Mountain, Mesa
Grande, Sunshine Summit, Ranchita and Oak Grove. The Mountain Empire Sub-region contains
Tecate, Potrero, Boulevard, Campo, Jacumba, and the remainder of the plan area. The
Community Planning Areas are Alpine, Bonsall, Borrego Springs, Boulevard,
Crest/Dehesa/Granite Hills/Harbison Canyon, Cuyamaca, Descanso, Desert, Fallbrook, Hidden
Meadows, Jacumba, Jamul/Dulzura, Julian, Lake Morena/Campo, Lakeside/Pepper Drive-
Bostonia, Otay, Pala-Pauma, Palomar/North Mountain, Pendleton/Deluz, Pine Valley, Portrero,
Rainbow, Ramona, San Dieguito (Rancho Santa Fe), Spring Valley, Sweetwater, Tecate, Twin
Oaks, Valle De Oro, and Valley Center.
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SECTIBNTWO Multi-jurisdictional Participation information
SECTION 2 MULTI-JURISDICTIONAL PARTICIPATION
INFORMATION
2.1 LIST OF PARTICIPATING AND NON-PARTICIPATING JURISDICTIONS
The incorporated cities that participated in the planning process are Carlsbad, Chula Vista,
Coronado, Del Mar, El Cajon, Encinitas, Escondido, Imperial Beach, La Mesa, Lemon Grove,
National City, Oceanside, Poway, San Diego (City), San Marcos, Santee, Solana Beach,
Unincorporated (County), and Vista. There were no non-participating cities. The one Fire
Protection District that participated in the revision of the plan was the Rancho Santa Fe Fire
Protection District. Representatives from all participating jurisdictions, local businesses,
educational facilities, various public, private and non-profit agencies, media representatives and
the general public provided input into the preparation of the Plan. Local jurisdictional
representatives included but were not limited to fire chiefs/officials, police chiefs/officials,
planners and other jurisdictional officials/staff.
2.2 DESCRIPTION OF EACH JURISDICTION'S PARTICIPATION IN THE
PLANNING PROCESS
A Hazard Mitigation Working Group (HMWG) was established to facilitate the development of
the Plan. Representatives from each incorporated city, special district and the unincorporated
county were designated by their jurisdiction as the HMWG member. Each HMWG member
identified a Local Mitigation Planning Team for their jurisdiction that included decision-makers
from police, fire, emergency services, community development/planning, transportation,
economic development, public works and emergency response/services personnel. The
jurisdiction-level Local Mitigation Planning Team assisted in identifying the specific
hazards/risks that are of concern to each jurisdiction and to prioritize hazard mitigation measures.
The HMWG members brought this information to HMWG meetings held regularly to provide
jurisdiction-specific input to the multi-jurisdictional planning effort and to assure that all aspects
of each jurisdiction's concerns were addressed. A list of the lead contacts for each participating
jurisdiction is included in Section 3.2.
All HMWG members were provided an overview of hazard mitigation planning elements at the
HMWG meetings. This training was designed after the FEMA State and Local Mitigation
Planning How-to Guide worksheets, which led the HMWG members through the process of
defining the jurisdiction's assets, vulnerabilities, capabilities, goals and objectives, and action
items. The HMWG members were also given additional action items at each meeting to be
completed by their Local Mitigation Planning Team. HMWG members also participated in the
public workshops held to present the risk assessment, preliminary goals, objectives and actions.
In addition, several HMWG members met with OES staff specifically to discuss hazard-related
goals, objectives and actions. Preliminary goals, objectives and actions developed by jurisdiction
staff were then reviewed with their respective City Council, City Manager and/or representatives
for approval.
Throughout the planning process, the HMWG members were given maps of the profiled hazards
as well as detailed jurisdiction-level maps that illustrated the profiled hazards and critical. These
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SECTIONTWO Multi-jurisdjctional Participation information
maps were created using the data sources listed in Appendix B. These data sources contain the
most recent data available for the San Diego region. A very large portion of this data was
supplied by the regional GIS agency, SanGIS. The SanGIS data is updated periodically with the
new data being provided by the local agencies and jurisdictions. This ensured that the data used
was the most recent available for each participating jurisdiction. The HMWG members reviewed
these maps and provided updates or changes to the critical facility or hazard layers. Data received
from HMWG members were added to the hazard database and used in the modeling process
described in the Risk Assessment portion of the Plan (Section 4). The data used in this revision of
the plan is considered to be more accurate that that utilized in the original plan. Several
jurisdictions provided last-minute updates, for data not yet available in the SanGIS data. They
are:
City of Chula Vista - provided additional GIS/infrastructure data.
City of Encinitas - provided critical infrastructure data.
City of Escondido - provided updated local fire threat and geo-hazard data
All 18 incorporated cities, the Water Authority and the Rancho Santa Fe Fire Protection District
provided OES with edits to critical facilities within their jurisdictions.
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SECTIBNTHREE Planning Process Documentation
SECTION 3 PLANNING PROCESS DOCUMENTATION
3.1 DESCRIPTION OF PLANNING COMMITTEE FORMATION
The San Diego County Operational Area consists of the County of San Diego and the eighteen
incorporated cities located within the county's borders. Planning for emergencies, training and
exercises are all conducted on a regional basis. In 1961 the County and the cities formed a Joint
Powers Agency (JPA) to facilitate regional planning, training, exercises and responses. This JPA
is known as the Unified San Diego County Emergency Services Organization (USDCESO). Its'
governing body is the Unified Disaster Council (UDC). The membership of the UDC is defined
in the JPA. Each city and the County have one representative. Representatives from the cities
can be an elected official, the City Manager or from the municipal law enforcement or fire
agency. The County is represented by the Chairperson of the County Board of Supervisors, who
also serves as Chair of the UDC.
3.1.1 Invitation to Participate
The original development of the Hazard Mitigation Plan, as well as this current revision, was
conducted under the auspices of the UDC. At the direction of the UDC, the San Diego County
Office of Emergency Services (OES) acted as the lead agency in the revision of this plan.
Thomas Amabile, the representative for the San Diego County OES, requested input from each
jurisdiction in the county. Each municipality and special district was formally invited to attend a
meeting to develop an approach to the planning process and to form the HMWG Committee (See
Appendix A). These invitations were in the form of an email to each member jurisdiction.
Invitations were also emailed to each Water District and Fire Protection District within the
County. At the June 18,2009 UDC meeting, it was again announced that the plan was reaching
the five year mark and required updating. Each jurisdiction also confirmed their participation on
the HMWG. In addition to the eighteen incorporated cities, OES provided an opportunity for
neighboring communities, local and regional agencies involved in hazard mitigation activities,
agencies that have the authority to regulate development, as well as business, academia and other
private and non-profit interested to be involved in the planning process. Some of those parties are
listed in Section 3.2 below. The committee was formed as a working group to undertake the
planning process and meeting dates were set for all members of the committee and interested
parties to attend. Local jurisdictional representatives included but were not limited to fire
chiefs/officials, police chiefs/officials, planners and other jurisdictional officials/staff.
3.2 NAME OF PLANNING COMMITTEE AND ITS MEMBERS
The HMWG is comprised of representatives from San Diego County (County), each of the 18
incorporated cities in the County and interested public agencies and citizens, as listed above in
Section 2.1. The HMWG met regularly, and served as a forum for the public to voice their
opinions and concerns about the mitigation plan. Although several jurisdictions sent several
representatives to the HMWG meetings, each jurisdiction selected a lead representative who
acted as the liaison between their jurisdictional Local Mitigation Planning Team and the HMWG.
Each local team, made up of other jurisdictional staff/officials met separately and provided
additional local-level input to the leads for inclusion into the Plan. These lead representatives are:
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SECTIONTHREE Planning Process Documentation
Lead HMWG Representatives for Participating Jurisdictions:
City of Carlsbad, David Harrison, Fire Department
City of Chula Vista, Justin Gipson, Fire Department
City of Coronado, Ed Hadfield, Fire Department
City of Del Mar, David Scherer, Public Works Director
City of El Cajon, Rick Sitta, Fire Department.
City of Encinitas, Tom Gallup, Fire Department.
City of Escondido, Don Rawson, Fire Department
City of Imperial Beach, Leticia Hernandez, Fire Department
City of La Mesa, Greg McAlpine, Fire Dept.
City of Lemon Grove, Tim Smith, Fire Department
City of National City, Walter Amadee, Fire Department
City of Oceanside, Ken Matsumoto, Fire Department
City of Poway, Jon Canavan, Fire Department
City of San Diego, Eugene Ruzzini, Office of Homeland Security
City of San Marcos, Scott McClintock, Fire Department
City of Santee, Dave Miller, Fire Department
City of Solana Beach, Dismas Abelman, Fire Department
City of Vista, Jeff Berg, Fire Department
County of San Diego, Thomas Amabile, OES
County of San Diego, Cynthia Lerma, OES GIS
Rancho Santa Fe FPD, Mike Scott
In addition to members of the public, representatives of the following agencies/organizations
provided input to and feedback on the plan:
California Emergency Management Agency (Cal E.M.A.)
Emergency Preparedness and Disaster Medical Response Personnel
San Diego County Hazardous Materials Division
San Diego Data Processing Center
San Diego Resource Conservation District
San Diego County Department of Planning and Land Use
Finally, the Unified Disaster Council's (UDC) Operations Section members were kept updated on
the plan. The UDC Operations Section is an advisory group whose members represent:
American Red Cross
Chambers of Commerce
Federal Agencies (USN, USMC, USCG, DHS)
Hospitals
Port of San Diego
State Agencies (CalEMA, DMV, CalTrans)
School Districts
Universities and colleges
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SEBTIBNTHREE Planning Process Documentation
Utilities (Power- SDG&E, Water - San Diego County Water Authority and Water
Districts, Cable, telephone and internet - Cox Communications)
3.3 HAZARD MITIGATION WORKING GROUP MEETINGS
The Hazard Mitigation Working Group met regularly. The following is a list of meeting dates and
results of meetings (see Appendix A for sign-in sheets, meeting agendas, and meeting minutes).
HMWG Meeting Dates/Results of Meeting:
HMWG Meeting 1: 4/1/09 - Kickoff and Formation of HMWG
HMWG Meeting 2: 5/28/09 - Overview of Planning Process/Assessing Risks
HMWG Meeting 3: 6/25/09 - Overview of Planning Process/Profiling Hazards
HMWG Meeting 4: 7/30/09 - Review Risk Assessment/Development of Mitigation Plan
HMWG Meeting 5: 11/04/09 - Capabilities Assessment/Goals, Objectives, and Actions
The distribution of the draft and final plans was accomplished electronically. Other meetings
included individual meeting with jurisdictions and meetings with GIS staff.
3.4 PLANNING PROCESS MILESTONES
The approach taken by San Diego County relied on sound planning concepts and a methodical
process to identify County vulnerabilities and to propose the mitigation actions necessary to avoid
or reduce those vulnerabilities. Each step in the planning process was built upon the previous,
providing a high level of assurance that the mitigation actions proposed by the participants and
the priorities of implementation are valid. Specific milestones in the process included:
Risk Assessment (April, 2009 - August. 2009) - The HMWG used the list of hazards from the
current Multi-jurisdictional Hazard Mitigation Plan determine if they were still applicable to the
region and if there were any new threats identified that should be added to the plan. Specific
geographic areas subject to the impacts of the identified hazards were mapped using a Geographic
Information System (GIS). The HMWG had access to updated information and resources
regarding hazard identification and risk estimation. This included hazard specific maps, such as
floodplain delineation maps, earthquake shake potential maps, and wildfire threat maps; GIS-
based analyses of hazard areas; the locations of infrastructure, critical facilities, and other
properties located within each jurisdiction and participating special district; and an estimate of
potential losses or exposure to losses from each hazard.
The HMWG also conducted a methodical, qualitative examination of the vulnerability of
important facilities, systems, and neighborhoods to the impacts of future disasters. GIS data and
modeling results were used to identify specific vulnerabilities that could be addressed by specific
mitigation actions. The HMWG also reviewed the history of disasters in the County and assessed
the need for specific mitigation actions based on the type and location of damage caused by past
events. The process used during the completion of the initial plan was utilized for the update.
Finally, the assessment of community vulnerabilities included a review of current codes, plans,
policies, programs, and regulations used by local jurisdictions to determine whether existing
provisions and requirements adequately address the hazards that pose the greatest risk to the
community. Again, this was a similar process to that used in the original plan.
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Goals, Objectives and Alternative Mitigation Actions (August, 2009- November, 2009) - Based
on this understanding of the hazards faced by the County, the goals and objectives identified in
the current plan were reviewed to see what had been completed and could be removed and which
were not able to be completed due to funding or other roadblocks. Members then added those
goals, objectives or actions as required for the completion of the update. This was done by the
members working with their local planning groups and in a series of one-on-one meetings with
OES staff.
Mitigation Plan and Implementation Strategy (October-December, 2009) - each jurisdiction
reviewed their priorities for action from among their goals, objectives and actions, developing a
specific implementation strategy including details about the organizations responsible for
carrying out the actions, their estimated cost, possible funding sources, and timelines for
implementation.
Work Group Meetings April, 2009 - November, 2009) - As listed in Section 3.3 a series of
HMWG meetings were held in which the HMWG considered the probability of a hazard
occurring in an area and its impact on public health and safety, property, the economy, and the
environment, and the mitigation actions that would be necessary to minimize impacts from the
identified hazards. These meetings were held every month or two (depending on the progress
made) starting May 28th and continued through November 2009. The meetings evolved as the
planning process progressed, and were designed to aid the jurisdictions in completing worksheets
that helped define hazards within their jurisdictions, their existing capabilities and mitigation
goals and action items for the Mitigation Plan.
3.5 PUBLIC INVOLVEMENT
The San Diego County HMWG posted the draft plan online. The public was invited to review
and comment on the plan. Press releases from the County of San Diego as well as links from
various emergency management as well as the websites for the individual cities/agencies, pointed
the public the plan. .
Public Response Questions where provided on the website in order to develop lists of potential
mitigation actions by soliciting community input regarding vulnerabilities and potential
solutions. Citizens participated by answering the questions and emailing their input to the
County of San Diego (see Appendix A for a copy of the questions).
Press Releases were prepared and released to solicit public review and comment (see Appendix
A for copies of press releases and public notices).
A Hazard Mitigation Plan Web Site was developed to provide the public with information.
Items posed on the web site included the current plan, and draft updates, by jurisdiction or
agency.
Public involvement was valuable in the development of the Plan. One recommendation was
received from Mr. Brian Holland, form the City of Chula Vista, requesting we include Climate
Change into the updated plan. Details of this comment are provided in Appendix A. While the
HMWG agrees that Climate Change could alter the impact of some of the hazards identified (by
changing their severity, area of impact etc.), the HMWG determined that there is not enough data
on Climate Change to include it in the current revision of the plan. It was determined that that
this issue would be examined and addressed in the next revision in 2015. Feedback given during
the public meetings led to the addition of a topic for discussion during the next update process.
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3.6 EXISTING PLANS OR STUDIES REVIEWED
HMWG team members and their corresponding Local Mitigation Planning Teams prior to and
during the planning process reviewed several plans, studies, and guides. These plans included
FEMA documents, emergency services documents as well as county and local general plans,
community plans, local codes and ordinances, and other similar documents. These included:
San Diego County/Cities General Plans
Various Local Community Plans
Various Local Codes and Ordinances
Local Mitigation Planning Guidance, FEMA July 1, 2008
State and Local Mitigation Planning How to Guide FEMA 386-1 September 2002
State and Local Mitigation Planning How to Guide FEMA 386-2 August 2001
State and Local Mitigation Planning How to Guide FEMA 386-3 April 2003
State and Local Mitigation Planning How to Guide FEMA 386-4 August 2003
State and Local Mitigation Planning How to Guide FEMA 386-6 May 2005
State and Local Mitigation Planning How to Guide FEMA 386-7 September 2003
Interim Hazard Mitigation Planning Guidance for California Local Governments
FEMA CRS-DMA2K Mitigation Planning Requirements
Crosswalk Reference Document for Review and Submission of Local Mitigation Plans to the
State Hazard Mitigation Officer and FEMA Regional Office
Unified San Diego County Emergency Services Organization Operational Area Emergency
Plan dated September 2006
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SECTION 4 RISK ASSESSMENT
4.1 OVERVIEW OF THE RISK ASSESSMENT PROCESS
Risk Assessment requires the collection and analysis of hazard-related data in order to enable
local jurisdictions to identify and prioritize appropriate mitigation actions that will reduce losses
from potential hazards. The FEMA State and Local Mitigation Planning How-to Guide (How-to
Guide) identifies five Risk Assessment steps as part of the hazard mitigation planning process,
including: 1) identifying hazards, which involves determining those hazards posing a threat to a
study area, 2) profiling hazards, which involves mapping identified hazards and their geographic
extent, 3) identifying assets, which assigns value to structures and landmarks in the identified
hazard areas, 4) assessing vulnerability, which involves predicting the extent of damage to assets,
and 5) analyzing development trends, which assesses future development and population growth
to determine potential future threat from hazards. These steps are described in detail in the
following sections, first with an overall summary of hazard identification and data collection in
Section 4.2, then with a jurisdictional summary of hazards, assets and vulnerability in Section 4.3.
This is the same process followed in the development of the original plan in 2004. When the
revision process began in 2009 a complete review of the hazards identified in the original plan
was conducted to determine if they were still valid and should be kept as a target for mitigation
measures or removed from the list. We also reassessed those hazards that were not considered for
mitigation actions in 2005 to determine if that decision was still applicable or if they should be
move to the active list. Finally, we examined potential or emerging hazards to see if any should
be included on the active list.
The data used was the most recent data available from SanGIS and the participating jurisdictions.
This data changed the model results in some cases raising the risks and reducing it in others. The
overall result was a more accurate picture of the risks facing the region. An example of this is the
data for dam failure. The 2005 plan shows an exposed population of 368,240 and a potential
exposure for residential buildings of $22,408,095. The revised figures for the 2010 plan show the
exposed population has been reduced to 241.767, but the exposure for residential buildings has
increased slightly to $23,054,569.
Because there was only four years between approval of the plan and the start of the revision
process, we saw very little, if any, change in the active hazards and in their prioritization. We
believe that the events of the past five years demonstrate the accuracy of the 2005 plan. While
many of the mitigation measures listed in the original plan were accomplished, the risk of the
hazard did not significantly diminish. This is easily seen in both the wildfire and earthquake
hazards. While mitigation measures have been put in place (such as the update of the fire code
and vegetation management measures) wildfire remains, and will continue to be, the greatest risk
to the San Diego region. The HMG reviewed all events since 2004 (wildfires, etc.) and all were
profiled accurately in the original plan. The 2005 plan actually detailed the path of the 2007
firestorm. The review of the other hazards showed that the updated data was consistent with
previous growth in the region. The changes noted in the hazards and populations at risk (as
detailed in the HAZUS profiles and the analysis completed by our GIS experts) were not
significant enough to alter the impacts of the hazards. Consequently, there were no changes to
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the hazard profile required. Tables list new events that have occurred since 2005. Where no new
events are listed, not new events have occurred.
4.1.1 Identifying Hazards
Hazard identification is the process of identifying hazards that threaten an area including both
natural and man-made events. A natural event causes a hazard when it harms people or property.
Such events would include floods, earthquakes, tornadoes, tsunami, coastal storms, landslides,
and wildfires that strike populated areas. Man-made hazard events are caused by human activity
and include technological hazards and terrorism. Technological hazards are generally accidental
and/or have unintended consequences (for example, an accidental hazardous materials release).
Terrorism is defined by the Code of Federal Regulations as "...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." Natural hazards that have
harmed the County in the past are likely to happen in the future; consequently, the process of
identifying hazards includes determining whether or not the hazard has occurred previously.
Approaches to collecting historical hazard data include researching newspapers and other records,
conducting a planning document and report literature review in all relevant hazards subject areas,
gathering hazard-related GIS data, and engaging in conversation with relevant experts from the
community. In addition, a variety of sources were used to determine the full range of all potential
hazards within San Diego County. Even though a particular hazard may not have occurred in
recent history in San Diego County, it is important during the hazard identification stage to
consider all hazards that may potentially affect the study area.
4.1.2 Profiling Hazards
Hazard profiling entails describing the physical characteristics of past hazards such as their
magnitude, duration, frequency, and probability. This stage of the hazard mitigation planning
process involves creating base maps of the study area and then collecting and mapping hazard
event profile information obtained from various Federal, State, and local government agencies.
Building upon the original hazard profiles OES used the existing hazard data tables (created for
the original Hazard Mitigation Plan) and updated them using current data. The revised hazard
data was mapped to determine the geographic extent of the hazards in each jurisdiction in the
County. The level of risk associated with each hazard in each jurisdiction was also estimated and
assigned a risk level of high, medium or low depending on several factors unique to that
particular hazard. .
4.1.3 Identifying Assets
The third step of the risk assessment process entails identifying which assets in each jurisdiction
will be affected by each hazard type. Assets include any type of structure or critical facility such
as hospitals, schools, museums, apartment buildings, and public infrastructure. The inventory of
existing and proposed assets within the County was updated. The assets were then mapped to
show their locations and to determine their vulnerability to each hazard type. The HMWG also
considered proposed structures, including planned and approved developments, based upon a
review of the County's General Plan Land Use Element.
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4.1.4 Assessing Vulnerability
Vulnerability describes the degree to which an asset is susceptible to damage from a hazard.
Vulnerability depends on an asset's construction, contents and the economic value of its
functions. Like indirect damages, the vulnerability of one element of the community is often
related to the vulnerability of another. Often, indirect effects can be much more widespread and
damaging than direct effects. A vulnerability analysis predicts the extent of injury and damage
that may result from a hazard event of a given intensity in a given area. The vulnerability
assessment identifies the effects of natural and man-made hazard events by estimating the relative
exposure of existing and future population, land development, and infrastructure to hazardous
conditions. The assessment helps set mitigation priorities by allowing local jurisdictions to focus
attention on areas most likely to be damaged or most likely to require early emergency response
during a hazard event.
4.1.5 Repetitive Loss
Disaster records were reviewed for repetitive losses. No repetitive losses were found for Coastal
storms, erosion and Tsunamis, Dam Failures, Earthquakes, landslides, wildfire or liquefaction.
Review of the flooding hazard identified nine addresses suffering damage in two or more flood
events. The City of Lemon Grove had one address involved in a series of repetitive structure fires
caused by arson. A list of repetitive losses by jurisdiction is below:
Carlsbad 1 Structure Fire National City 0
Chula Vista 0 Oceanside 0
Coronado 0 Poway 0
Del Mar 3 Storm /Erosion San Diego 0
El Cajon 0 San Marcos 0
Encinitas 0 Santee 0
Escondido 0 Solana Beach 0
Imperial Beach 1 Flood Vista 0
La Mesa 0 County of San Diego 9 Flood
Lemon Grove 1 Structure Fire Rancho Santa Fe FPD 0
4.1.6 Analyzing Development Trends
This stage of the risk assessment process provides a general overview of land uses and
development planned to occur within the County. This overview is utilized to determine the type
and intensities of future development proposed for identified hazard areas. This information
provides the groundwork for decisions about mitigation strategies and locations in which these
strategies should be applied.
4.2 HAZARD IDENTIFICATION AND SCREENING
4.2.1 List of Hazards Prevalent in the Jurisdiction
The HMWG reviewed the hazards identified in the original Hazard Mitigation Plan and evaluated
each to see if they still posed a risk to the region. In addition, the hazards listed in the How-to
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Guide were also reviewed to determine if they should be added to the list of hazards to include in
the plan revision. All hazards identified by FEMA in the How-To-Guides were reviewed. They
include: avalanche, coastal storm, coastal erosion, dam failure, drought/water supply, earthquake,
expansive soils, extreme heat, flooding, hailstorm, house/building fire, land subsidence, landslide,
liquefaction, severe winter storm, tornado, tsunami, wildfire, windstorm, and volcano. Although
not required by the FEMA Disaster Mitigation Act of 2000, manmade hazards such as hazardous
materials release, nuclear materials release, and terrorism were also reviewed by the HMWG.
As part of the public input portion of the plan's development the HMWG was requested to
incorporate global warming as a hazard. It was the consensus of the group that global warming in
and of itself was not a hazard, but that the results of the ensuing climate change could be. It was
determined that the impacts of global warming would be considered during the next update cycle,
when additional data on the impacts of climate change is available.
4.2.2 Hazard Identification Process
As summarized above, hazard identification is the process of identifying all hazards that threaten
an area, including both natural and man-made events. In the hazard identification stage, The
HMWG determined hazards that potentially threaten San Diego County. The hazard screening
process involved narrowing the all-inclusive list of hazards to those most threatening to the San
Diego region. The screening effort required extensive input from a variety of HMWG members,
including representatives from City governments, County agencies, special districts, fire agencies
and law enforcement agencies, Red Cross, the California Emergency Management Agency, local
businesses, community groups, the 2006 Unified San Diego County Emergency Services
Organization Operational Area Emergency Plan, and the general public.
OES, with assistance of GIS experts from the County of San Diego's Department of Planning and
Land Use used information from FEMA and other nationally and locally available databases to
map the County's hazards, infrastructure, critical facilities, and land uses. This mapping effort
was utilized in the hazard screening process to determine which hazards would present the
greatest risk to the County of San Diego and to each jurisdiction within the County.
It was also determined that the coastal storm, erosion, and tsunami hazards should be profiled
together because the same communities in the County have the potential to be affected by all
three hazards. In the development of the initial plan,, the HMWG indicated that based on the fact
that the majority of the development in San Diego is relatively recent (within the last 60 years),
an urban type of fire that destroys multiple city blocks is not likely to occur alone, without a
wildfire in the urban/wild-land interface occurring first. Therefore, it was determined that
house/building fire and wildfire should be addressed as one hazard category in the plan. This
revised plan continues to discuss structure fire and wildfire together. Similarly, the original
addressed earthquake and liquefaction as one category because liquefaction does not occur unless
an adequate level of ground shaking from an earthquake occurs first.
The final list of hazards to be profiled for San Diego County was determined as
Wildfire/Structure Fire, Flood, Coastal Storms/Erosion/Tsunami, Earthquake/Liquefaction, Rain-
Induced Landslide, Dam Failure, Hazardous Materials Incidents, Nuclear Materials Release, and
Terrorism.
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Table 4.2-1 shows a summary of the hazard identification results for San Diego County.
Table 4.2-1 Summary of Hazard Identification Results
Hazard Data Collected for Hazard Identification Justification for Inclusion
Coastal Storms,
Erosion and
Tsunami
Historical Coastlines (NOAA)
Shoreline Erosion Assessment
(SANDAG)
Maximum Tsunami Run up Projections
(USCA OES)
FEMA FIRM Maps
FEMA Hazards website
Coastal Zone Boundary (CALTRANS)
Tsunamis and their Occurrence along
the San Diego County Coast (report,
Westinghouse Ocean Research
Laboratory)
Tsunami (article, Scientific American)
Storms in San Diego County (publication
of San Diego County Dept. of Sanitation
and Flood Control)
Coastal storms prompted 8 Proclaimed States of
Emergency from 1950-1997
Coastline stabilization measures have been
implemented at various times in the past
(erosion)
Extensive development along the coast
Dam Failure FEMA-HAZUS
Dam Inundation Data (SanGIS)
(SDCWA) (Oiivenhain Dam)
FEMA FIRM maps
Topography (SANDAG)
FEMA Hazards website
• Dam failure
• Several dams exist throughout San Diego
County
• Many dams over 30 years old
• Increased downstream development
Earthquake • USGS
• CGS
• URS
• CISN
• SanGIS
• SANDAG
• FEMA-HAZUS
• FEMA Hazards website
• Several active fault zones pass through San
Diego County
Floods FEMA FIRM Maps
Topography
Base flood elevations (FEMA)
Historical flood records
San Diego County Water Authority
San Diego County Dept. of Sanitation
and Flood Control
FEMA Hazards website
Much of San Diego County is located within the
100-year floodplain
Flash floods and other flood events occur
regularly during rainstorms due to terrain and
hydrology of San Diego County
There were 10 Proclaimed States of Emergency
between 1950-2009 for floods in San Diego
County
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Hazard Data Collected for Hazard Identification Justification for Inclusion
Hazardous
Materials Release
County of San Diego Dept. of
Environmental Health, Hazardous
Materials Division
• San Diego County has several facilities that
handle or process hazardous materials
• Heightened security concerns since September
2001
Landslide USGS
CGS
Tan Map Series
Steep slope data (SAN DAG)
Soil Series Data (SANDAG)
FEMA-HAZUS
FEMA Hazards website
NEH
Steep slopes within earthquake zones
characterize San Diego County, which creates
landslide risk.
There have been 2 Proclaimed States of
Emergency for landslides in San Diego County
Liquefaction • Soil-Slip Susceptibility (USGS)
• FEMA-HAZUS MH
• FEMA Hazards website
Steep slopes or alluvial deposit soils in low-lying
areas are susceptible to liquefaction during
earthquakes or heavy rains. San Diego County
terrain has both of these characteristics and lies
within several active earthquake zones
Nuclear Materials
Release
• San Onofre Nuclear Generating Station
(SONGS) and Department of Defense
The potential exists for an accidental release to
occur at San Onofre or from nuclear ships in
San Diego Bay
Heightened security concerns since September
2001
Terrorism • County of San Diego Environmental
Health Department Hazardous Materials
Division
The federal and state governments have
advised every jurisdiction to consider the
terrorism hazard
Heightened security concerns since September
2001
Wildfire/
Structure Fire
CDF-FRAP
USFS
CDFG
Topography
Local Fire Agencies
Historical fire records
FEMA Hazards website
San Diego County experiences wildfires on a
regular basis
8 States of Emergency were declared for
wildfires between 1950-2009
Terrain and climate of San Diego
Santa Ana Winds
Data in GIS format was projected into the State Plane, NAD 1983, California Zone VI Coordinate
System (US Survey Units Feet), and clipped to the San Diego County and Jurisdictional
boundaries. Data that was not available in GIS format was either digitized into GIS or kept in its
original format and used as a reference. A matrix of all data collected, including source, original
projection, scale and data limitations is included in Attachment B. Maps were generated depicting
the potential hazards throughout the county and distributed to the jurisdictions. Data and methods
that were ultimately used to determine risk levels and probability of occurrence for each hazard
are described in detail in the hazard profiling sections.
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4.2.3 Hazard Identification Sources
Once the hazards of concern for San Diego County were determined, the available data was
collected, using sources including the Internet, direct communication with various agencies,
discussions with in-house experts, and historical records. Specific sources included the United
States Geological Survey (USGS), California Geological Survey (CGS), Federal Emergency
Management Agency (FEMA) HAZUS, FEMA Flood Insurance Rate Maps (FIRM), United
States Forest Service (USFS), California Department of Forestry - Fire and Resource Assessment
Program (CDF-FRAP), National Oceanographic and Atmospheric Administration (NOAA), San
Diego Geographic Information Source (SanGIS), San Diego Association of Governments
(SANDAG), San Diego County Flood Control District, Southern California Earthquake Data
Center (SCEDC), California Seismic Safety Commission (CSSC), California Integrated Seismic
Network (CISN), California Department of Fish and Game (CDFG), Drought Outlook websites,
and input gathered from local jurisdictions districts and agencies. When necessary, agencies were
contacted to ensure the most updated data was obtained and used. Historical landmark locations
throughout the County were obtained from the National Register and from the San Diego
Historical Resources Board.
Table 4.2-1 also depicts data sources researched and utilized by hazard, as well as brief
justifications for inclusion of each hazard of concern in the San Diego region. See Appendix B
for a Data Matrix of all sources used to gather initial hazard information.
4.2.4 Non-Profiled Hazards
During the initial evaluation the HMWG determined that those hazards that were not included in
the original plan's profiling step because they were not prevalent hazards within the County, were
found to pose only minor or very minor threats to the County compared to the other hazards had
not changed and would not be included in the revision. The following table gives a brief
description of those hazards and the reason for their exclusion from the list.
Table 4.2-2
Summary of Hazards Excluded from Hazard Profiling
Hazard
Avalanche
Drought/water supply
Expansive soils
Description
A mass of snow moving down a slope.
There are two basic elements to a slide; a
steep, snow-covered slope and a trigger
Long periods without substantial rainfall.
Expansive soils shrink when dry and swell
when wet. This movement can exert
enough pressure to crack sidewalks,
driveways, basement floors, pipelines and
Reason for Exclusion
Snowfall in County mountains not significant; poses
very minor threat compared to other hazards
The San Diego region relies extensively on imported
water. Long periods without substantial rainfall in
Northern California and in the Colorado River watershed
would affect San Diego's water supply more than a local
rainfall deficit. Additionally, regional water conservation
and water management programs already in place
Presents a minor threat to limited portions of the County
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Hazard
Extreme heat
Hailstorm
Land subsidence
Severe winter storm
Tornado
Volcano
Windstorm
Description
even foundations
Temperatures that hover 10 degrees or
more above the average high temperature
for the region and last for several weeks
Can occur during thunderstorms that bring
heavy rains, strong winds, hail, lightning
and tornadoes
Occurs when large amounts of ground
water have been withdrawn from certain
types of rocks, such as fine-grained
sediments. The rock compacts because the
water is partly responsible for holding the
ground up. When the water is withdrawn,
the rocks fall in on themselves.
Large amounts of falling or blowing snow
and sustained winds of at least 35 miles per
hour occurring for several hours
A tornado is a violent windstorm
characterized by a twisting, funnel-shaped
cloud. It is spawned by a thunderstorm (or
sometimes as a result of a hurricane) and
produced when cool air overrides a layer of
warm air, forcing the warm air to rise
rapidly. The damage from a tornado is a
result of the high wind velocity and wind-
blown debris.
A volcano is a mountain that is built up by
an accumulation of lava, ash flows, and
airborne ash and dust. When pressure from
gases and the molten rock within the
volcano becomes strong enough to cause
an explosion, eruptions occur
A storm with winds that have reached a
constant speed of 74 miles per hour or
more
Reason for Exclusion
Prolonged heat waves are not a historically documented
hazard in the region
Occurs during severe thunderstorms; most likely to
occur in the central and southern states; no historical
record of this hazard in the region.
Soils in the County are mostly granitic. Presents a minor
threat to limited parts of the county. No historical record
of this hazard in the region.
Minor threat in mountains of the County. No historical
record of this hazard in the region.
Less than one tornado event occurs in the entire State
of California in any given year; poses very minor threat
compared to other hazards. No historical record of this
hazard in the region.
No active volcanoes in San Diego County. No historical
record of this hazard in the region.
Maximum wind speed in the region is less than 60 miles
per hour and would not be expected to cause major
damage or injury (see Figure 4.3.1)
4.3 HAZARD PROFILES
A hazard profile is a description of the physical characteristics of a hazard and a determination of
various hazard descriptors, including magnitude, duration, frequency, probability, and extent. The
hazard data that were collected in the hazard identification process were mapped to determine the
geographic extent of the hazards in each jurisdiction in the County and the level of risk associated
with each hazard. Most hazards were given a risk level of high, medium or low depending on
several factors unique to the hazard. The hazards identified and profiled for San Diego County, as
well as the data used to profile each hazard are presented in this section. The hazards are
presented in alphabetical order; and this does not signify level of importance to the HMWG.
Because Nuclear Materials Release, Hazardous Materials Release and Terrorism hazards are
sensitive issues and release of information could pose further unnecessary threat, the HMWG
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decided that each of these hazards would be discussed separately in a "For Official Use Only"
Appendix and would be exempt from public distribution and disclosure by Section 6254 (99) of
the California Government Code (See separately bound Attachment A).
4.3.1 Coastal Storms, Erosion and Tsunami
4.3.1.1 Nature of Hazard
These three hazards were mapped and profiled as a group because many of the factors and risks
involved are similar and limited to the coastal areas. Coastal storms can cause increases in tidal
elevations (called storm surge), wind speed, and erosion. The most dangerous and damaging
feature of a coastal storm is storm surge. Storm surges are large waves of ocean water that sweep
across coastlines where a storm makes landfall. Storm surges can inundate coastal areas, wash out
dunes, and cause backwater flooding. If a storm surge occurs at the same time as high tide, the
water height will be even greater.
Coastal erosion is the wearing away of coastal land. It is commonly used to describe the
horizontal retreat of the shoreline along the ocean, and is considered a function of larger
processes of shoreline change, which include erosion and accretion. Erosion results when more
sediment is lost along a particular shoreline than is re-deposited by the water body, and is
measured as a rate with respect to either a linear retreat or volumetric loss. Erosion rates are not
uniform and vary over time at any single location. Various locations along the Coast of San
Diego County are highly susceptible to erosion. Erosion prevention and repair measures such as
installation of seawalls and reinforcement of cliffs have been required in different locations along
the San Diego coast in the past.
A tsunami is a series of long waves generated in the ocean by a sudden displacement of a large
volume of water. Underwater earthquakes, landslides, volcanic eruptions, meteoric impacts, or
onshore slope failures can cause this displacement. Tsunami waves can travel at speeds averaging
450 to 600 miles per hour. As a tsunami nears the coastline, its speed diminishes, its wavelength
decreases, and its height increases greatly. After a major earthquake or other tsunami-inducing
activity occurs, a tsunami could reach the shore within a few minutes. One coastal community
may experience no damaging waves while another may experience very destructive waves. Some
low-lying areas could experience severe inland inundation of water and deposition of debris more
than 3.000 feet inland.
4.3.1.2 Disaster History
There were eight (10) Proclaimed States of Emergency for Weather/Storms in San Diego County
between 1950 and 2005. In January and February 1983, the strongest-ever El Nino-driven coastal
storms caused over 116 million dollars in beach and coastal damage. Thirty-three homes were
destroyed and 3900 homes and businesses were damaged. Other coastal storms that caused
notable damage were during the El Nino winters of 1977-1978 and 1997-1998 and 2003-2004.
Coastal erosion is an ongoing process that is difficult to measure, but can be seen in various areas
along the coastline of San Diego County. Unstable cliffs at Beacon's Beach in Encinitas caused a
landslide that killed a woman sitting on the beach in January 2000. In 1942, the Self-Realization
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Fellowship building fell into the ocean because of erosion and slope failure caused by
ground water oversaturated the cliffs it was built on.
Wave heights and run-up elevations from tsunami along the San Diego Coast have historically
fallen within the normal range of the tides (Joy 1968). The largest tsunami effect recorded in San
Diego since 1950 was May 22,1960, which had a maximum wave height 2.1 feet (NOAA, 1993).
In this event, 80 meters of dock were destroyed and a barge sunk in Quivera Basin. Other
tsunamis felt in San Diego County occurred on November 5, 1952, with a wave height of 2.3 feet
and caused by an earthquake in Kamchatka; March 9, 1957, with a wave height of 1.5 feet; May
22,1960, at 2.1 feet; March 27,1964 with a wave height of 3.7 feet and September 29, 2009 with
a wave height of 0.5 feet.. It should be noted that damage does not necessarily occur in direct
relationship to wave height, illustrated by the fact that the damages caused by the 2.1-foot wave
height in 1960 were worse than damages caused by several other tsunamis with higher wave
heights.
4.3.1.3 Location and Extent/Probability of Occurrence and Magnitude
Figure 4.3.1 displays the location and extent of coastal storm/coastal erosion/tsunami hazard areas
for the County of San Diego. As shown in this figure, the highest risk zones in San Diego County
are located within the coastal zone of San Diego County. Coastal storm hazards are most likely
during El Nino events. As shown on Figure 4.3.1, maximum wind speeds along the coast are not
expected to exceed 60 miles per hour, resulting in only minor wind-speed related damage. Coastal
erosion risk is highest where geologically unstable cliffs become over-saturated by irrigation or
rainwater. The greatest type of tsunami risk is material damage to small watercraft, harbors, and
some waterfront structures (Joy 1968), with flooding along the coast as shown in the run-up
projections on Figure 4.3.1.
Data used to profile this group of hazards included the digitized flood zones from the FEMA
FIRM Flood maps, NOAA historical shoreline data, and Caltrans' coastal zone boundary for the
coastal storm/erosion hazard (refer to Appendix B for complete data matrix). Maximum tsunami
run up projections modeled by the University of Southern California and distributed by the
California Office of Emergency Services were used for identifying tsunami hazard. The tsunami
model was the result of a combination of inundation modeling and onsite surveys and shows
maximum projected inundation levels from tsunamis along the entire coast of San Diego County.
NOAA historical tsunami effects data were also used, which showed locations where tsunami
effects have been felt, and when available, details describing size and location of earthquakes that
caused the tsunamis. The Shoreline Erosion Assessment and Atlas of the San Diego Region
Volumes I and II (SANDAG, 1992) were reviewed for the shoreline erosion category. This
publication shows erosion risk levels of high, moderate and low for the entire coastline of San
Diego County.
For modeling purposes, the VE Zone of the FEMA FIRM map series was used as the high hazard
value for coastal storms and coastal erosion. The VE Zone is defined by FEMA as the coastal
area subject to a velocity hazard (wave action). Coastal storm and erosion risk were determined to
be high if areas were found within the VE zone of the FEMA FIRM maps. Tsunami hazard risk
levels were determined to be high if an area was within the maximum projected tsunami run-up
and inundation area.
4-10
COASTAL
STORM/EROSION/TSUNAMI
COUNTY OF SAN DIEGO (1 of 4)
HAZARD MITIGATION PLANNING
Profiling Hazards
Tsunami Layers
0 Historic Tsunami Effect Felt
Maximum Tsunami Projected Runup
Erosion/Coastal Storm Layers:
011 FEMAVE Zone (High Risk)
Base Layers:
Incorporated City Boundary
Freeways
Major Roads
Streams
Lakes
FIGURE NO. 4.3.1
DPLU GIS ^
COASTAL
STORM/EROSION/TSUNAMI
COUNTY OF SAN DIEGO (2 of 4)
HAZARD MITIGATION PLANNING
Profiling Hazards
Tsunami Layers
0 Historic Tsunami Effect Felt
Maximum Tsunami Projected Runup
Erosion/Coastal Storm Layers:
m FEMAVE Zone (High Risk)
Base Layers:
J Incorporated City Boundary
Freeways
Major Roads
Streams
Lakes
SOURCES SANGIS (Roatte, Incorporated City Boundaries Rivers. La
County of San Diego (OES Tsunami Inundation Areas, LUEG. FEMAVE Zoi
THIS MAP/DATAIS PROVIDED WITHOUT WARRANTY OF ANY KIND. EITHER EXPRESS OR IMPLIED,INCLUDING BUT NOT LIMITED TO. THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
FOR A PARTICULAR PURPOSE
be reproduced without the written permission of SANDAG This product may contain information repri
with permission granted by RAND MCNALLY & COMPANY® to SanGIS This map is copyrighted by
RAND MCNALLY & COMPANY® II is unlawful to copy or reproduce all or any part thereof, whether forpersonal use or resale, without the prior, written permission ol RAND MCNALLY « COMPANY®.Copyighf SanGIS 2009 -All Rights Reseived Full lex! of this legal
K J=ire Ser
COASTAL
STORM/EROSION/TSUNAMI
COUNTY OF SAN DIEGO (3 of 4)
HAZARD MITIGATION PLANNING
Profiling Hazards
Tsunami Layers
0 Historic Tsunami Effect Felt
Maximum Tsunami Projected Runup
Erosion/Coastal Storm Layers:
Jjfj^ FEMAVE Zone (High Risk)
Base Layers:
Incorporated City Boundary
Freeways
Major Roads
Streams
^] Lakes
UNINCORPORATED
S.D. COUNTY
SOLANA BEACH
VBNTUR*6A« BERNARDINO
Pacific Ocean VBAJA
FIGURE NO. 4.3.1
DPLU CIS
THIS MAP/DATA IS PROVIDED WITHOUT WARRANTY OF ANY KIND EITHER EXPRESS OR IMPLIED.
INCLUDING BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
FOR A PARTICULAR PURPOSENote This product may contain information from the SANDAG Regional Information Sysbe reproduced without the written permission of SANDAG This product may contain information reproduced
i granted by RAND MCNALLY & COMPANY® to SanGIS This map is copyrighted by
RAND MCNALLY S COMPANY® It is unlawful to copy or reproduce all 01 any part the
personal use or resale, without the prior written permission of RAND MCNALLY & COMPANY.-
Copyright SanGIS 2009 • All Rights Reserved Full text of this legalnotice can be found at http //www sangis org/Legal_Notice htm
CITY OF
SAN DIEGO
OCEANSIDE
:CARLSBAD
COASTAL
STORM/EROSION/TSUNAMI
COUNTY OF SAN DIEGO (4 of 4)
HAZARD MITIGATION PLANNING
Profiling Hazards
LEGEND:
Tsunami Layers
0 Historic Tsunami Effect Felt
Maximum Tsunami Projected Runup
Erosion/Coastal Storm Layers:
m FEMA VE Zone (High Risk)
Base Layers:
J Incorporated City Boundary
Freeways
Major Roads
Streams
~1 Lakes
,VISTA
\
*
Approximate Maximum Wind Zones:
BERNARDO
Pacific Ocean
OVERVIEW MAP:
RIVERSIDE
SAN DIEGO IMPERIAL
'acific Oceanf
FIGURE NO. 4.3.1
0.3 0.6 1.2
{•Miles
SOURCES SANGIS (Roads. Incorporated City Boundanes. Rivers. Lakes)County of San Diego IOES Tsunami Inundation Areas. LUEG FEMAVEZone)WOAA (Historic Tsuraimi Effect Felt)
THIS MAPfDATA IS PROVIDED WITHOUT WARRANTY OF ANY KIND. EITHER EXPRESS OR IMPLIED.
INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
FOR A PARTICULAR PURPOSE
Note This product may contain information from the SANDAG Regional Information System which cannot
with permission granted by RAND MCNALLY 1 COMPANY® to SanGIS Tfirs map is copyrighted byRAND MCNALLY & COMPANYfD It is unlawful to copy or reproduce all or any part thereof, whether for
personal use or resale, without the prior, written permission of RAND MCNALLY & COMPANY®
Copyright SanGIS 2009 - All Rights Reserved Full tent of this legal
notice can be found at httpy/www sangis oro;Legal_Notke htm
al Storm Erosion Tsunami
•
0
ENCINITAS
SOLANA BEA&H
SECTIONFOUR Bisk Assessment
4.3.2 Dam Failure
4.3.2.1 Nature of Hazard
Dam failures can result in severe flood events. When a dam fails, a large quantity of water is
suddenly released with a great potential to cause human casualties, economic loss, lifeline
disruption, and environmental damage. A dam failure is usually the result of age, poor design, or
structural damage caused by a major event such as an earthquake or flood.
4.3.2.2 Disaster History
Two major dam failures have been recorded in San Diego County. The Hatfield Flood of 1916
caused the failure of the Sweetwater and Lower Otay Dams, resulting in 22 deaths. Most of those
deaths were attributed to the failure of Lower Otay Dam (County of San Diego Sanitation and
Flood Control, 2002).
4.3.2.3 Location and Extent/Probability of Occurrence and Magnitude
Figure 4.3.2 displays the location and extent of dam failure hazard areas for the County of San
Diego. Dam failures are rated as one of the major "low-probability, high-loss" events.
Dam inundation map data were used to profile dam failure risk levels (refer to Appendix B for
complete data matrix). These maps were created by agencies that own and operate dams. OES
obtained this data from SanGIS, a local GIS data repository. The dam inundation map layers
show areas that would be flooded in the event of a dam failure.. If an area lies within a dam
inundation zone, it was considered at high risk. A dam is characterized as high hazard if it stores
more than 1,000 acre-feet of water, is higher than 150 feet tall, has potential for downstream
property damage, and potential for downstream evacuation. Ratings are set by FEMA and
confirmed with site visits by engineers. A simple way to define high risk of dam failure is if
failure of the dam is likely to result in loss of human life. Most dams in the County are greater
than 50 years old and are characterized by increased hazard potential due to downstream
development and increased risk due to structural deterioration in inadequate spillway capacity
(Unified San Diego County Emergency Services Organization Operational Area Emergency Plan,
2006).
4-19
SECTIONFOUR Risk Assessment
This page intentionally left blank
4-20
RED MOUNTAIN RES
PULGAS LAKE DAM
LAKE ONEILL DAM
LOWER STEHLE*UPPER|JHLY
PILGRIM CREEK DAM
USSILICAFWP.ONDS
DIXON^,
WOHLFORD LAKE
MELROSpAVENUE
4) SAN M'ARCOS ssa
SAN MARCOS 848
,
AKEHODGENCINITAS ^'>~SAN DIEGUITO
I RAMONA
MT WOODSON>O.C®UNTY 4S RANCH
FAIRBANKS) (UPPER /4S SAN VICENTE STORAGE POND 1 UNINCORPORATED
(/\ S.D.COUNTYIBERNARDRES
POWAoiAMOND VALLEY LAKE FB^AN VICENTE STORAGE POND 3
BLOSSOM VALLY RES
PALO VERDE
}
LAKE LOVELAND Thing Valley 856 Dam
CORTE MADERA
Mary Jo 841-002 Dam,HENRY JR
ISWEETWATER MAIN
EASTLAKE
CUPPER OTAY
BONITA LONG1 CANYONNOTE:
Some "insignfficant" dams are excluded from this analysis as they are not
officially recognized by FEMA. or do not have inundation analysis study areas
These dams include:
Alvarado Regulating 8-013 Dam
Black Mountain Reservoir
Campo Lake 850 Dam
Cottonwood 861 Dam
Guajome Lake
Pechstein Dam & Tank
Santee Lakes
Whalen Lake
Willow Tree
IMPERIAL
BEACH
DAM FAILURE
COUNTY OF SAN DIEGO
HAZARD MITIGATION PLANNING
Profiling Hazards
LEGEND:
Dam Inundation Areas:
^% Dam Inundation Areas (High Risk)
Rodriquez Dam not shown, located in Tijuana. Mexico
Dam Location/Relative Hazard Rating
A High
A Significant
A Low
A Unknown
Emergency Action Plan:
O Yes
• No
w Not Required
) Unknown
Base Layers:
Lakes
I I Incorporated City Boundary
Freeways
Major Roads
Streams
FIGURE NO. 4.3.2
A
16
I Miles
SOURCES SANGIS (Roads. I 5. Lakes, Dams. Dam Inundation Dalai
THIS MAP/DATA IS PROVIDED WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED,
INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESSFORAPARTICULAR PURPOSE.
Note This product may contain information from the SANDAG Regional Information System which cannot
be reproduced without the witten permission of SANDAG This product may contain information reproducedwith permission granted by RAND MCNALLY & COMPANY® to SanGIS This map is copyrighted by
RAND MCNALLY & COMPANY® It is unlawful to copy or reproduce all or any part thereof, whether forpersonal use or resale, without the prior, written permission of RAND MCNALLY & COMPANY®
Copyright SanGIS 2009 -All Rights Reserved Full text of this legal
notice can be found at http.//wv/w sangis org/Legal_Notice htm
K \Fire ServicesUasttsVOES Hazmit Mitigation Plan\Dam Failure\CQSD_DamFailure mxd
SECTIONFOUR Bisk Assessment
4.3.3 Earthquake
4.3.3.1 Nature of Hazard
An earthquake is a sudden motion or trembling that is caused by a release of strain accumulated
within or along the edge of the Earth's tectonic plates. The effects of an earthquake can be felt far
beyond the site of its occurrence. They usually occur without warning and, after just a few
seconds, can cause massive damage and extensive casualties. Common effects of earthquakes are
ground motion and shaking, surface fault ruptures, and ground failure. Ground motion is the
vibration or shaking of the ground during an earthquake. When a fault ruptures, seismic waves
radiate, causing the ground to vibrate. The severity of the vibration increases with the amount of
energy released and decreases with distance from the causative fault or epicenter. Soft soils can
further amplify ground motions. The severity of these effects is dependent on the amount of
energy released from the fault or epicenter. One way to express an earthquake's severity is to
compare its acceleration to the normal acceleration due to gravity. The acceleration due to gravity
is often called "g". A 100% g earthquake is very severe. More damage tends to occur from
earthquakes when ground acceleration is rapid. Peak ground acceleration (PGA) is a measure of
the strength of ground movement. PGA measures the rate in change of motion relative to the
established rate of acceleration due to gravity (980 cm/sec/sec). PGA is used to project the risk of
damage from future earthquakes by showing earthquake ground motions that have a specified
probability (10%, 5%, or 2%) of being exceeded in 50 years. These ground motion values are
used for reference in construction design for earthquake resistance. The ground motion values can
also be used to assess relative hazard between sites, when making economic and safety decisions.
Another tool used to describe earthquake intensity is the Richter scale. The Richter scale was
devised as a means of rating earthquake strength and is an indirect measure of seismic energy
released. The scale is logarithmic with each one-point increase corresponding to a 10-fold
increase in the amplitude of the seismic shock waves generated by the earthquake. In terms of
actual energy released, however, each one-point increase on the Richter scale corresponds to
about a 32-fold increase in energy released. Therefore, a magnitude (M) 7 earthquake is 100
times (10 X 10) more powerful than a M5 earthquake and releases 1,024 times (32 X 32) the
energy. An earthquake generates different types of seismic shock waves that travel outward from
the focus or point of rupture on a fault. Seismic waves that travel through the earth's crust are
called body waves and are divided into primary (P) and secondary (S) waves. Because P waves
move faster (1.7 times) than S waves they arrive at the seismograph first. By measuring the time
delay between arrival of the P and S waves and knowing the distance to the epicenter,
seismologists can compute the Richter scale magnitude for the earthquake.
The Modified Mercalli Scale (MMI) is another means for rating earthquakes, but one that
attempts to quantify intensity of ground shaking. Intensity under this scale is a function of
distance from the epicenter (the closer to the epicenter the greater the intensity), ground
acceleration, duration of ground shaking, and degree of structural damage. This rates the level of
severity of an earthquake by the amount of damage and perceived shaking (Table 4.3-1).
4-23
SECTIONFOUR Risk Assessment
Table 43-1
Modified Mercalli Intensity Scale
MMI
Value
i.
II.
III.
IV.
V.
VI.
VII.
VIII.
IX.
X.
XI.
Description of
Shaking Severity
Light
Moderate
Strong
Very Strong
Very Violent
Summary Damage
Description
Pictures Move
Objects Fall
Nonstructurai
Damage
Moderate Damage
Extreme Damage
Full Description
Not felt
Felt by persons at rest, on upper floors, or favorably placed.
Felt indoors. Hanging objects swing. Vibration like passing of
light trucks. Duration estimated. May not be recognized as an
earthquake.
Hanging objects swing. Vibration like passing of heavy trucks;
or sensation of a jolt like a heavy ball striking the walls.
Standing motorcars rock. Windows, dishes, doors rattle. In
the upper range of IV, wooden walls and frame creak.
Felt outdoors; direction estimated. Sleepers wakened. Liquids
disturbed, some spilled. Small unstable objects displaced or
upset. Doors swing, close, open. Shutters, pictures move.
Pendulum clock stop, start, change rate.
Felt by all. Many frightened and run outdoors. Persons walk
unsteadily. Windows, dishes, glassware broken. Knickknacks,
books, etc., off shelves. Pictures off walls. Furniture moved or
overturned. Weak plaster and masonry D cracked.
Difficult to stand. Noticed by drivers of motorcars. Hanging
objects quiver. Furniture broken. Damage to masonry D,
including cracks. Weak chimneys broken at roofline. Fall of
plaster, loose bricks, stones, tiles, cornices. Some cracks in
masonry C. Small slides and caving in along sand or gravel
banks. Concrete irrigation ditches damaged.
Steering of motorcars affected. Damage to masonry C, partial
collapse. Some damage to masonry B; none to masonry A.
Fall of stucco and some masonry walls. Twisting, fall of
chimneys, factory stacks, monuments, towers, and elevated
tanks. Frame houses moved on foundations if not bolted
down; loose panel walls thrown out. Cracks in wet ground
and on steep slopes.
Most masonry and frame structures destroyed with their
foundations. Some well-built wooden structures and bridges
destroyed. Serious damage to dams, dikes, embankments.
Large landslides. Water thrown on banks of canals, rivers,
lakes, etc. Sand and mud shifted horizontally on beaches and
flat land.
Rails bent greatly. Underground pipelines completely out of
services.
Damage nearly total. Large rock masses displaced. Lines of
sight and level distorted. Objects thrown into air.
Several major active faults exist in San Diego County, including the Rose Canyon, La Nacion,
Elsinore, San Jacinto, Coronado Bank and San Clemente Fault Zones. The Rose Canyon Fault
Zone is part of the Newport-Inglewood fault zone, which originates to the north in Los Angeles,
and the Vallecitos and San Miguel Fault Systems to the south in Baja California (see Figure
4.3.3). The Rose Canyon Fault extends inland from La Jolla Cove, south through Rose Canyon,
along the east side of Mission Bay, and out into San Diego Bay. The Rose Canyon Fault is
considered to be the greatest potential threat to San Diego as a region, due to its proximity to
4-24
SECTIONFOUR Risk Assessment
areas of high population. The La Nacion Fault Zone is located near National City and Chula
Vista. The Elsinore Fault Zone is a branch of the San Andreas Fault System. It originates near
downtown Los Angeles, and enters San Diego County through the communities of Rainbow and
Pala; it then travels in a southeasterly direction through Lake Henshaw, Santa Ysabel, Julian; then
down into Anza-Borrego Desert State Park at Agua Caliente Springs, ending at Ocotillo,
approximately 40 miles east of downtown. The San Jacinto Fault is also a branch of the San
Andreas Fault System. This fault branches off from the major fault as it passes through the San
Bernardino Mountains. Traveling southeasterly, the fault passes through Clark Valley, Borrego
Springs, Ocotillo Wells, and then east toward El Centre in Imperial County. This fault is the most
active large fault within County of San Diego. The Coronado Bank fault is located about 10 miles
offshore. The San Clemente Fault lies about 40 miles off La Jolla and is the largest offshore fault
at 110 miles or more in length (Unified San Diego County Emergency Services Organization
Operational Area Emergency Plan, 2000).
4.3.3.2 Disaster History
Historic documents record that a very strong earthquake struck San Diego on May 27, 1862,
damaging buildings in Old Town and opening up cracks in the earth near the San Diego River
mouth. This destructive earthquake was centered on either the Rose Canyon or Coronado Bank
faults and descriptions of damage suggest that it had a magnitude of about 6.0 (M6). The
strongest recently recorded earthquake in San Diego County was a M5.3 earthquake that occurred
on July 13, 1986 on the Coronado Bank Fault, 25 miles west of Solana Beach. In recent years
there have been several moderate earthquakes recorded within the Rose Canyon Fault Zone as it
passes beneath the City of San Diego. Three temblors shook the city on 17 June 1985 (M3.9,4.0,
3.9) and a stronger quake occurred on 28 October 1986 (M4.7) (Demere, SDNHM website 2003).
The most recent significant earthquake activity occurred on June 15, 2004 with a M5.3 on the San
Diego Trough Fault Zone approximately 50 miles SW of San Diego. It was reported as a IV on
the MMI (Southern California Seismic Network).
4.3.3.3 Location and Extent/Probability of Occurrence and Magnitude
Figure 4.3.3 displays the location and extent of the profiled earthquake hazard areas for San
Diego County. This is based on a USGS earthquake model that shows probabilistic peak ground
acceleration for every location in San Diego County. Since 1984, earthquake activity in San
Diego County has increased twofold over the preceding 50 years (Demere, SDNHM website
2003). All buildings that have been built in recent decades must adhere to building codes that
require them to be able to withstand earthquake magnitudes that create a PGA of 0.4 or greater.
Ongoing field and laboratory studies suggest the following maximum likely magnitudes for local
faults: San Jacinto (M6.4 to 7.3), Elsinore (M6.5 to 7.3), Rose Canyon (M6.2 to 7.0), La Nacion
(M6.2 to 6.6), Coronado Bank (M6.0 to 7.7), San Clemente (M6.6 to 7.7) (Demere, SDNHM
website 2003).
4-25
SECTIONFOUR Risk Assessment
This page intentionally left blank
4-26
UNINCORPORATED
-S'D.COUNTY
EARTHQUAKE
COUNTY OF SAN DIEGO
HAZARD MITIGATION PLANNING
Profiling Hazards
LEGEND:
— Earthquake Faults
Probabilistic Peak Ground Acceleration:
| 0-0.15 peak Horizontal Acceleration (%g)
n is 02 wittl 10% Probabil'ty of Exceedance"
0.21 -0.25
0.26-0.3
0.31 -0.4
0.41 - 0.6
in 50 years
I >0.81
_] Incorporated City Boundary
s*\/ Rivers
Freeways
Major Roads
Lakes
OVERVIEW MAP:
FIGURE NO. 4.3.3
A
3.75 7.5 15
I Miles
SOURCES SANGIS (Roads, Incorporated City Boundaries. RiverState of California (Earthquake Faults!
USGS (PGA, 2009]
THIS MAP/DATA IS PROVIDED WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED
INCLUDING BUT NOT LIMITED TO. THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
FOR A PARTICULAR PURPOSE
Note This product may contain information from the SANDAG Regional Information System which cannot
be reproduced without the written permission of SANDAG This product may contain information reproduced
with permission granted By RAND MCNALLY & COMPANY® to SanGIS This map is copyrighted by
RAND MCNALLY & COMPANY® It is unlawful to copy or reproduce all or any part thereof, whether forpersonal use or resale, without the prior, written permission of RAND MCNALLY & COMPANY®
Copyright SanGIS 2009 - All Rights Reserved Full text of this legal
notice can be found at http //www sangis org/Legal_Notice htm
Data Source California Department of Forestry and Fire Protection
K /Fire Services/lasks/OES HazMit Mitigation Plan/Earthquake/COSD_Earthquake mxd
SECTIONFOUR RisK Assessment
Data used to profile earthquake hazard included probabilistic PGA data from the United States
Geological Survey (USGS) and a Scenario Earthquake Shake map for Rose Canyon from the
California Integrated Seismic Network (CISN) (refer to Appendix B for complete data matrix).
From these data, the HMWG determined that risk level for earthquake is determined to be high if
an area lies within a 0.3 or greater PGA designation. Earthquakes were modeled using HAZUS-
MH, which uses base information to derive probabilistic peak ground accelerations much like the
PGA map from USGS that was used for the profiling process.
4.3.4 Flood
4.3.4.1 Nature of Hazard
A flood occurs when excess water from snowmelt, rainfall, or storm surge accumulates and
overflows onto a river's bank or to adjacent floodplains. Floodplains are lowlands adjacent to
rivers, lakes, and oceans that are subject to recurring floods. Most injury and death from flood
occurs when people are swept away by flood currents, and property damage typically occurs as a
result of inundation by sediment-filled water. Average annual precipitation in San Diego County
ranges from 10 inches on the coast to approximately 45 inches on the highest point of the
Peninsular Mountain Range that transects the county, and 3 inches in the desert east of the
mountains.
Several factors determine the severity of floods, including rainfall intensity and duration. A large
amount of rainfall over a short time span can result in flash flood conditions. A sudden
thunderstorm or heavy rain, dam failure, or sudden spills can cause flash flooding. The National
Weather Service's definition of a flash flood is a flood occurring in a watershed where the time of
travel of the peak of flow from one end of the watershed to the other is less than six hours. There
are no watersheds in San Diego County that have a longer response time than six hours. Flash
floods in this county range from the stereotypical wall of water to a gradually rising stream. The
central and eastern portions of San Diego County are most susceptible to flash floods where
mountain canyons, dry creek beds, and high deserts are the prevailing terrain.
4.3.4.2 Disaster History
From 1770 until 1952, 29 floods were recorded in San Diego County. Between 1950 and 1997,
flooding prompted 10 Proclaimed States of Emergency in the County of San Diego. Several very large
floods have caused significant damage in the County of San Diego in the past. The Hatfield Flood of
1916 destroyed the Sweetwater and Lower Otay Dams, and caused 22 deaths and $4.5 million in
damages. The flood of 1927 caused $117,000 in damages, and washed out the Old Town railroad
bridge (Bainbridge, 1997). The floods of 1937 and 1938 caused approximately $600,000 in damages.
(County of San Diego Sanitation and Flood Control, 1996). In the 1980 floods, the San Diego River at
Mission Valley peaked at 27,000 cubic feet per second (cfs) and caused $120 million in damage
(Bainbridge, 1997).
Table 4.3-2 displays a history of flooding in San Diego County, as well as loss associated with
each flood event.
4-29
SECTIONFOUR Risk Assessment
Table 43-2
Historical Records of Large Floods in San Diego County
Date
1862
1891
1916
1927
1937&
1938
1965
1969
1979
1980
Oct-87
1995
2003
Sept 2004
Oct 2004
Jan-Mar
2005
Loss Estimation
Not available
Not available
$4.5 million
$117,000
$600,000
Not available
Not available
$2,766,268
$120 million
$640,500
$Tens of Millions
Not Available
Not Available
Not Available
Not Available
Source of Estimate
County of San Diego Sanitation and Flood
Control
County of San Diego Sanitation and Flood
Control
County of San Diego Sanitation and Flood
Control
County of San Diego Sanitation and Flood
Control
County of San Diego Sanitation and Flood
Control
San Diego Union
San Diego Union
County OES
County of San Diego Sanitation
and Flood Control; Earth Times
State OES
County OES
County OES
San Diego Union-Tribune
San Diego Union-Tribune
Cal EMA (formerly State OES) '
Comments
6 weeks of rain
33 inches in 60 hours
Destroyed
2 dams, 22 deaths
Washed out railroad bridge Old
Town
N/A
6 killed
All of State declared disaster
area
Cities of La Mesa, Lemon
Grove, National City, San
Marcos, San Diego and
unincorporated areas
San Diego river topped out in
Mission Valley
N/A
San Diego County Declared
Disaster Area
Storm floods areas impacted
by the 2003 firestorm.
Series of storms caused
localized flooding
Flash-flood in Borrego Springs
San Diego County Declared
Disaster Area
43.43 Location and Extent!Probability of Occurrence and Magnitude
In regions such as San Diego, without extended periods of below-freezing temperatures, floods
usually occur during the season of highest precipitations or during heavy rainfalls after long dry
spells. The areas surrounding the river valleys in all of San Diego County are susceptible to
flooding because of the wide, flat floodplains surrounding the riverbeds, and the numerous
structures that are built in the floodplains. One unusual characteristic of San Diego's hydrology is
that it has a high level of variability in its runoff. The western watershed of the County of San
Diego extends about 80 miles north from the Mexican border and approximately 45 miles east of
4-30
SECTIONFOUR Bisk Assessment
the Pacific Ocean. From west to east, there are about 10 miles of rolling, broken coastal plain, 10
to 15 miles of foothill ranges with elevations of 600 to 1,700 feet; and approximately 20 miles of
mountain country where elevations range from 3,000 to 6,000 feet. This western watershed
constitutes about 75% of the County, with the remaining 25% mainly desert country. There are
over 3,600 miles of rivers and streams which threaten residents and over 200,000 acres of flood-
prone property. Seven principle streams originate or traverse through the unincorporated area.
From north to south they are the Santa Margarita, San Luis Rey, San Dieguito, San Diego,
Sweetwater, Otay, and Tijuana Rivers (Unified San Diego County Emergency Services
Organization Operational Area Emergency Plan, 2006).
FEMA FIRM data was used to determine hazard risk for floods in the County of San Diego.
FEMA defines flood risk primarily by a 100-year flood zone, which is applied to those areas with
a 1% chance, on average, of flooding in any given year. Any area that lies within the FEMA-
designated 100-year floodplain is designated as high risk. Any area found in the 500-year
floodplain is designated at low risk. Base flood elevations (BFE) were also used in the HAZUS-
MH modeling process. A BFE is the elevation of the water surface resulting from a flood that has
a 1 % chance of occurring in any given year (i.e. the height of the base flood).
Figure 4.3.4 displays the location and extent of flood hazard areas for the County of San Diego.
As shown in this figure, high hazard (100-year floodway) zones in San Diego County are
generally concentrated within the coastal areas, including bays, coastal inlets and estuaries. Major
watershed areas connecting the local mountain range to the coastal region, where flash floods are
more common, show several 100-year flood hazard areas.
4-31
SECTION R) I R Risk Assessment
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4-32
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UNINCORPORATED
S.D.COUNTY
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NOTE:
Some "insignificant" dams are excluded from this analysis as they are not
officially recognized by FEMA, or do not have inundation analysis study areas
These darns include:
Alvarado Regulating 8-013 Dam
Black Mountain Reservoir
Campo Lake 850 Dam
Cottonwood 861 Dam
Guajome Lake
Pechstein Dam & Tank
Santee Lakes
Whalen Lake
Willow Tree
IMPERIAL
BEACH
FLOOD
COUNTY OF SAN DIEGO
HAZARD MITIGATION PLANNING
Profiling Hazards
LEGEND:•^ m^^^^^mm
Flood Layers
^ Dam Location
m 100 year Floodplain
500 year Floodplain
Base Layers:
| | Incorporated City Boundary
Freeways
Major Roads
Streams
Lakes
OVERVIEW MAP:
FIGURE NO. 4.3.4
t of Mjimirii; awJ I jrul f V
A
12
I Miles
SOURCES SANGIS (Roads. Incorporated City
County of San Diego (Floodplainsi
City of Carlsbad (Floodplains)
oundaries. Rivers, Lakes. Dam
THIS MAP/DATA IS PROVIDED WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED
INCLUDING BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
FOR A PARTICULAR PURPOSE
Note This product may contain information from the SANDAG Regional Information System which cannot
Be reproduced witrwut the written permission of SANDAG This product may contain information reproduced
With permission granted by RAND MCNALLY & COMPANY® to SanGIS This map is copyrighted by
RAND MCNALLY & COMPANY® It is unlawful to copy or reproduce all or any part thereof, whether forpersonal use or resale, without the prior written permission of RAND MCNALLY & COMPANY®
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K \Fire Services«asks\OES Hazmit Mitigation Plan\Flood\COSD_Flood.mxd