Santa Clara County Multijurisdictional Hazard Mitigation Plan Table of Contents xxi
12.9 Scenario ............................................................................................................................... 254
12.10 Issues ................................................................................................................................... 254
12.11 Consequence Analysis....................................................................................................... 255 13 Flood............................................................................................................................................. 257
13.1 General Background........................................................................................................... 257
13.1.1 Measuring Floods and Floodplains ................................................................................... 258
13.1.2 Floodplain Ecosystems ..................................................................................................... 258
13.1.3 Effects of Human Activities ............................................................................................... 259
13.1.4 Federal Flood Programs ................................................................................................... 259
13.2 Hazard Profile ...................................................................................................................... 265
13.2.1 Types of Flood-Related Hazards ...................................................................................... 266
13.2.2 Principal Flooding Sources ............................................................................................... 268
13.2.3 Past Events ....................................................................................................................... 269
13.2.4 Location............................................................................................................................. 273
13.2.5 Frequency ......................................................................................................................... 274
13.2.6 Severity ............................................................................................................................. 275
13.2.7 Warning Time.................................................................................................................... 288
13.3 Cascading Impacts ............................................................................................................. 288
13.4 Exposure .............................................................................................................................. 289
13.4.1 Population ......................................................................................................................... 289
13.4.2 Property............................................................................................................................. 290
13.4.3 Critical Facilities and Infrastructure................................................................................... 292
13.4.4 Environment ...................................................................................................................... 296
13.5 Vulnerability......................................................................................................................... 297
13.5.1 Population ......................................................................................................................... 298
13.5.2 Property............................................................................................................................. 300
13.5.3 Critical Facilities and Infrastructure................................................................................... 307
13.5.4 Environment ...................................................................................................................... 309
13.5.5 Economic Impact............................................................................................................... 309
13.6 Future Trends in Development .......................................................................................... 310
13.7 Scenario ............................................................................................................................... 310
13.8 Issues ................................................................................................................................... 311 14 Landslide/Mass Movement......................................................................................................... 313
14.1 General Background........................................................................................................... 313
14.1.1 Landslide Types ................................................................................................................ 313
14.1.2 Landslide Modeling ........................................................................................................... 315
14.1.3 Landslide Causes.............................................................................................................. 316
14.1.4 Landslide Management..................................................................................................... 317
14.1.5 Land Subsidence Effects .................................................................................................. 317
14.2 Hazard Profile ...................................................................................................................... 318
14.2.1 Past Events ....................................................................................................................... 318
14.2.2 Location............................................................................................................................. 327
14.2.3 Frequency ......................................................................................................................... 330
14.2.4 Severity ............................................................................................................................. 330
14.2.5 Warning Time.................................................................................................................... 330
14.3 Cascading Impacts ............................................................................................................. 331
Santa Clara County Multijurisdictional Hazard Mitigation Plan Table of Contents xxii
14.4 Exposure .............................................................................................................................. 331
14.4.1 Population ......................................................................................................................... 331
14.4.2 Property............................................................................................................................. 332
14.4.3 Critical Facilities and Infrastructure................................................................................... 333
14.4.4 Environment ...................................................................................................................... 336
14.5 Vulnerability......................................................................................................................... 336
14.5.1 Population ......................................................................................................................... 336
14.5.2 Property............................................................................................................................. 337
14.5.3 Critical Facilities and Infrastructure................................................................................... 337
14.5.4 Environment ...................................................................................................................... 338
14.6 Future Trends in Development .......................................................................................... 338
14.7 Scenario ............................................................................................................................... 338
14.8 Issues ................................................................................................................................... 338 15 Tsunami........................................................................................................................................ 341
15.1 General Background........................................................................................................... 341
15.1.1 Tsunami............................................................................................................................. 341
15.1.2 Seiche ............................................................................................................................... 343
15.2 Hazard Profile ...................................................................................................................... 343
15.2.1 Past Events ....................................................................................................................... 343
15.2.2 Location............................................................................................................................. 343
15.2.3 Frequency ......................................................................................................................... 344
15.2.4 Severity ............................................................................................................................. 345
15.2.5 Warning Time.................................................................................................................... 345
15.2.6 Extent ................................................................................................................................ 346
15.3 Cascading Impact................................................................................................................ 348
15.4 Exposure and Vulnerability................................................................................................ 348
15.4.1 Population ......................................................................................................................... 348
15.4.2 Property............................................................................................................................. 349
15.4.3 Critical Facilities and Infrastructure.................................................................................... 349
15.4.4 Environment ...................................................................................................................... 349
15.5 Future Trends in Development .......................................................................................... 349
15.6 Scenario ............................................................................................................................... 350
15.7 Issues ................................................................................................................................... 350 16 Other Hazards of Interest ........................................................................................................... 353
16.1 General Background........................................................................................................... 353
16.1.1 EMAP Consequence Analysis .......................................................................................... 354
16.2 Intentional Hazards ............................................................................................................. 355
16.2.1 Terrorism and Weapons of Mass Destruction................................................................... 355
16.2.2 Active Threat ..................................................................................................................... 361
16.2.3 Hazard Profile.................................................................................................................... 363
16.2.4 Cyber Threats.................................................................................................................... 366
16.2.5 Hazard Profile.................................................................................................................... 369
16.3 Technological Incidents ..................................................................................................... 370
16.3.2 Hazard Profile.................................................................................................................... 378
16.3.3 Utility Failure, Power Outages, and Public Safety Power Shutoff..................................... 379
16.3.4 Hazard Profile.................................................................................................................... 382
Santa Clara County Multijurisdictional Hazard Mitigation Plan Table of Contents xxiii
16.4 Epidemic and Pandemic..................................................................................................... 384
16.4.2 Hazard Profile.................................................................................................................... 391
16.5 Fog........................................................................................................................................ 392
16.5.1 Hazard Profile.................................................................................................................... 393
16.6 Identified Needs................................................................................................................... 394
16.7 Related Plans....................................................................................................................... 396 17 Mitigation Strategy...................................................................................................................... 397
17.1 Goals and Objectives.......................................................................................................... 397
17.1.1 Guiding Principle ............................................................................................................... 397
17.1.2 Goals ................................................................................................................................. 397
17.1.3 Objectives.......................................................................................................................... 398
17.2 Mitigation Alternatives........................................................................................................ 398
17.3 Santa Clara County 2023 Mitigation Action Plan ............................................................. 411
17.4 Financial Capabilities ......................................................................................................... 430
17.4.1 Federal .............................................................................................................................. 430
17.4.2 State .................................................................................................................................. 437
17.4.3 Local.................................................................................................................................. 440
17.5 Action Plan Prioritization ................................................................................................... 440
17.5.1 Benefit-Cost Review.......................................................................................................... 441
17.6 Plan Adoption...................................................................................................................... 442
17.7 Plan Maintenance Strategy ................................................................................................ 442
17.8 Plan Implementation ........................................................................................................... 443
17.9 Plan Maintenance Element................................................................................................. 443
17.9.1 Plan Update....................................................................................................................... 444
17.9.2 Grant Monitoring and Coordination................................................................................... 445
17.9.3 Continuing Public Involvement.......................................................................................... 445
17.9.4 Incorporation into Other Planning Mechanisms ................................................................ 446 List of Tables
Table 1: Average Overall Hazard Risk Index Results..................................................................................xii Table 2: Summary of Changes in the 2023 MJHMP ....................................................................................7 Table 3: External Stakeholders Invited to Be Involved in Planning Process ..............................................13 Table 4: Planning Partner Main Points of Contact......................................................................................17 Table 5: One-on-One Meetings with Planning Partners .............................................................................18 Table 6: Summary of Public Outreach ........................................................................................................29 Table 7: Plan Development Chronology and Milestones............................................................................31 Table 8: Presidential Disaster Declarations8F ..............................................................................................35 Table 9: Normal Precipitation and Temperatures in the Operational Area, 1981–202210F...........................37 Table 10: Unincorporated County Land Use...............................................................................................38 Table 11: Critical Facilities and Infrastructure in the Operational Area ......................................................39 Table 12: Recent Population Data13F ............................................................................................................42 Table 13: Hourly Living Wage Calculation for Santa Clara County, California (2022)23F .............................49
Santa Clara County Multijurisdictional Hazard Mitigation Plan Table of Contents xxiv
Table 14: Probability of Hazards.................................................................................................................72 Table 15: Hazard Risk Ranking by Jurisdiction ..........................................................................................73 Table 16: Average Overall Hazard Risk Index Results...............................................................................74 Table 17: Hazus Model Data Documentation .............................................................................................79 Table 18: Mercalli Scale and Peak Ground Acceleration Comparison45F .....................................................87 Table 19: National Earthquake Hazard Reduction Program Soil Classification System46F ..........................87 Table 20: Recent Earthquakes Magnitude 5.0 or Larger Within a 100-Mile Radius of the Operational Area ....................................................................................................................................................................89 Table 21: Earthquake Probabilities for the San Francisco Bay Area Region, 2014–204368F .....................101 Table 22: Earthquake Exposure by Jurisdiction........................................................................................104 Table 23: Loss Estimates for 100-Year Probabilistic Earthquake.............................................................105 Table 24: Loss Estimates for 500-Year Probabilistic Earthquake.............................................................105 Table 25: Loss Estimates for San Andreas Fault Scenario Earthquake...................................................106 Table 26: Loss Estimates for Hayward Fault Scenario Earthquake .........................................................106 Table 27: Loss Estimates for Calaveras Fault Scenario Earthquake .......................................................107 Table 28: Estimated Earthquake-Caused Debris .....................................................................................108 Table 29: Number of Critical Facilities Exposed to Earthquakes..............................................................109 Table 30: Estimated Earthquake Impact on Persons ...............................................................................110 Table 31: Age of Structures in Operational Area ......................................................................................111 Table 32: Estimated Damage to Critical Facilities from 100-Year Earthquake.........................................112 Table 33: Essential Facility Functionality in 100-Year Probabilistic Earthquake ......................................113 Table 34: Estimated Damage to Critical Facilities from 500-Year Earthquake.........................................113 Table 35: Estimated Damage to Critical Facilities from Hayward Fault....................................................113 Table 36: Estimated Damage to Critical Facilities from San Andreas Fault .............................................114 Table 37: Estimated Damage to Critical Facilities from Calaveras...........................................................114 Table 38: Damage to Potable Water Systems by Hazus Scenario ..........................................................116 Table 39: Damage to Waste Water Systems by Hazus Scenario ............................................................116 Table 40: EMAP Consequence Analysis: Earthquake..............................................................................120 Table 41: Past Wildfire Events ..................................................................................................................123 Table 42: Record of Fire Affecting Operational Area................................................................................132 Table 43: Population Within Wildfire Hazard Areas ..................................................................................138 Table 44: Exposure and Value of Structures in Moderate to High Wildfire Hazard Areas .......................139 Table 45: Land Within the Wildfire Hazard Classification Areas...............................................................140 Table 46: Critical Facilities within Moderate to High Wildfire Hazard Areas .............................................141 Table 47: Critical Facilities Within 100 Meters of Moderate to High Wildfire Hazard Areas .....................141 Table 48: Loss Estimates for Wildfire within Moderate to High Wildfire Hazard Class.............................145 Table 49: EMAP Consequence Analysis: Wildfire ....................................................................................148 Table 50: NOAA Geomagnetic Storms Space Weather Scale and Potential Effects123F.............................160 Table 51: NOAA Solar Radiation Storms Space Weather Scale and Potential Effects124F..........................161 Table 52: NOAA Radio Blackouts Space Weather Scale and Potential Effects125F.....................................162 Table 53: 2001–2022 Heavy Rain and Hail Events ..................................................................................163 Table 54: 2001–2022 Extreme Temperature Events................................................................................166 Table 55:2002-2022 High Wind Events ....................................................................................................167 Table 56: 1951–2022 Tornado Events......................................................................................................168 Table 57: Population by Jurisdiction .........................................................................................................171 Table 58: EMAP Consequence Analysis Inclement Weather...................................................................174 Table 59: U.S. Department of Agriculture Disaster Declarations Including Santa Clara County, 2017– 2022 ..........................................................................................................................................................187 Table 60: Recent Federal and State Drought Responses ........................................................................191 Table 61: EMAP Consequence Analysis: Drought ...................................................................................199 Table 62: Average Maximum Temperature – Santa Clara County187F.........................................................205 Table 63: Number of Extreme Heat Days Per Year (Heat Is above 92.7 oF) Santa Clara County18F........206 Table 64: Average Annual Precipitation – Santa Clara County189F ..............................................................206 Table 65: Potential Direct and Related Climate Change Impacts in the Operational Area ......................208 Table 66: Climate Change Impacts on Natural and Other Hazards .........................................................209 Table 67: Wildfire – Projected Santa Clara County Acres Burned ...........................................................212
Santa Clara County Multijurisdictional Hazard Mitigation Plan Table of Contents xxv
Table 68: Population and Buildings at Risk – Santa Clara County...........................................................213 Table 69: Silicon Valley 2.0 Santa Clara County Sea Level Rise Projections and Inundation Layers .....222 Table 70: Estimated Population Residing in Sea Level Rise Inundation Areas .......................................223 Table 71: Structure Type in Sea Level Rise Inundation Areas .................................................................224 Table 72: Structure and Contents Value in Sea Level Rise Inundation Areas .........................................225 Table 73: Structure and Contents Value in Sea Level Rise Inundation Areas, Unincorporated Santa Clara County .......................................................................................................................................................225 Table 74: Critical Facilities in Sea Level Rise Inundation Areas...............................................................226 Table 75: EMAP Consequence Analysis: Climate Change ......................................................................227 Table 76: Dams Classified as a High Hazard or an Extremely High Hazard Risk 217F ,
218F ..............................231
Table 77: Levees in Santa Clara County 24F ...............................................................................................238 Table 78: Potential Downstream Hazard from Dams25F..............................................................................245 Table 79: Estimated Exposure and Value of Structures in the Dam Failure Inundation Area..................247 Table 80: Population in Dam Inundation Area ..........................................................................................248 Table 81: Value of Exposed Structures in the Dam Inundation Area by Jurisdiction ...............................250 Table 82: EMAP Consequence Analysis: Dam Failure ............................................................................255 Table 83: NFIP Status in the Operational Area ........................................................................................261 Table 84: CRS Community Status in the Operational Area246F....................................................................264 Table 85: History of Flood Events257F
,
258F........................................................................................................270 Table 86: Crop Insurance Claims Paid from Excessive Moisture and Flood, 2003-2022259F ......................272 Table 87: Summary of Peak Discharges Within the Operational Area260F ...................................................275 Table 88: Population Within the 10-Percent, 1-Percent, and 0.2-Percent Annual Chance Flood Hazard Areas .........................................................................................................................................................289 Table 89: Value of Structures in the 10-Percent Annual Chance Flood Hazard Area..............................290 Table 90: Value of Structures in the 1-Percent Annual Chance Flood Hazard Area................................291 Table 91: Value of Structures in the 0.2-Percent Annual Chance Flood Hazard Area.............................292 Table 92: Critical Facilities in the 10-Percent Annual Chance Flood Hazard Area ..................................293 Table 93: Critical Facilities in the 1-Percent Annual Chance Flood Hazard Area ....................................293 Table 94: Critical Facilities in the 0.2-Percent Annual Chance Flood Hazard Area .................................294 Table 95: Habitats Expected to Be Impacted by Riverine Flooding265F........................................................296 Table 96: Estimated Flood Impact on Persons .........................................................................................298 Table 97: Loss Estimates for 10-Percent-Annual-Chance Flood..............................................................300 Table 98: Loss Estimates for 1-Percent-Annual-Chance Flood................................................................301 Table 99: Loss Estimates for 0.2-Percent-Annual-Chance Flood.............................................................302 Table 100: Estimated Flood-Caused Debris .............................................................................................303 Table 101: Flood Insurance Statistics268F.....................................................................................................304 Table 102: Date of Floodplain Management Regulation Adoption ...........................................................305 Table 103: Repetitive Loss Properties ......................................................................................................306 Table 104: Substantial Damage/Substantial Improvement Implementation.............................................307 Table 105: Estimated Damage to Critical Facilities and Infrastructure from the 10% Annual Chance Flood ..................................................................................................................................................................307 Table 106: Estimated Damage to Critical Facilities and Infrastructure from the 1% Annual Chance Flood ..................................................................................................................................................................308 Table 107: Estimated Damage to Critical Facilities and Infrastructure from the 0.2% Annual Chance Flood ..................................................................................................................................................................308 Table 108: EMAP Consequence Analysis: Flood .....................................................................................312 Table 109: Landslide Events in Santa Clara County27F
,
278F
,
279F
,
280F
,
281F..................................................................319 Table 110: Population Exposed to Landslide Hazard...............................................................................331 Table 111: Exposure and Value of Structures in Moderate to High Landslide Risk Areas ......................332 Table 112: Acreage in Moderate to High Landslide Hazard Areas ..........................................................333 Table 113: Critical Facilities and Infrastructure in Moderate to Very High Landslide Risk Areas.............335 Table 114: Loss Potential Based on All Building Stock in Aggregated Landslide Areas..........................337 Table 115: EMAP Consequence Analysis: Landslide/Mass Movement ...................................................339 Table 116: Tsunami Intensity Scale297F ........................................................................................................346 Table 117: EMAP Consequence Analysis: Tsunami ................................................................................351 Table 118: EMAP Consequence Analysis: Other Hazards of Interest .....................................................354
Santa Clara County Multijurisdictional Hazard Mitigation Plan Table of Contents xxvi
Table 119: Event Profiles for Terrorism301F ..................................................................................................357 Table 120: Santa Clara County Hazardous Materials Spills 2019–202232F................................................372 Table 121: Corrosion Type........................................................................................................................375 Table 122: Leak Classifications ................................................................................................................377 Table 123: Electric Providers in Santa Clara County30F..............................................................................381 Table 124: Power Shutoffs Statewide31F .....................................................................................................382 Table 125: COVID-19 Cases Countywide and by City of Residence36F .....................................................386 Table 126: Disease Outbreaks Identified in Santa Clara County, 2018–202234F .......................................387 Table 127: Alternatives to Mitigate the Dam and Levee Failure Hazard ..................................................399 Table 128: Alternatives to Mitigate the Drought Hazard ...........................................................................400 Table 129: Alternatives to Mitigate the Earthquake Hazard .....................................................................401 Table 130: Alternatives to Mitigate the Flooding Hazard ..........................................................................403 Table 131: Alternatives to Mitigate the Landslide/Mass Movement Hazard.............................................406 Table 132: Alternatives to Mitigate the Inclement Weather Hazard..........................................................407 Table 133: Alternatives to Mitigate the Tsunami Hazard ..........................................................................408 Table 134: Alternatives to Mitigate the Wildfire Hazard............................................................................410 Table 135: County of Santa Clara 2023 Action Items...................................Error! Bookmark not defined.
Table 136: FEMA Mitigation Funding Sources .........................................................................................431 Table 137: Additional Federal Funding Sources.......................................................................................434 Table 138: State Mitigation Funding Sources ...........................................................................................437 Table 139: Plan Maintenance Matrix ........................................................................................................443 Table 140: Survey Results Level of Hazard Concern............................................................................... A-2 Table 141: Level of Concern for Climate Change Impacts ....................................................................... A-2 Table 142: Types of Stakeholders Represented....................................................................................... A-3 Table 143: Public Comments .................................................................................................................... A-3 Table 144: General Feedback Received ................................................................................................ A-16 List of Figures
Figure 1: Planning Partners Meeting ..........................................................................................................20 Figure 2: Planning Partners Mitigation Strategy Meeting ...........................................................................21 Figure 3: Picture of Public Survey Announcement .....................................................................................23 Figure 4: Public Survey Media Announcement...........................................................................................24 Figure 5: City of Campbell Social Media Outreach.....................................................................................25 Figure 6: Hazard Exposure and Social Vulnerability Map for Santa Clara Valley ......................................27 Figure 7: Public and Stakeholder Meeting with 99 Participants..................................................................28 Figure 8: Public and Stakeholder Meeting with 104 Participants................................................................29 Figure 9: Samples of Public Comment Period Advertisements ..................................................................30 Figure 10: Santa Clara County Operational Area (Planning Area).............................................................34 Figure 11: Critical Facilities in the Operational Area...................................................................................40 Figure 12: Critical Infrastructure in the Operational Area ...........................................................................41 Figure 13: Overall Age Distribution in the Operational Area17F.....................................................................44 Figure 14: Race Distribution in the Operational Area19F ...............................................................................45 Figure 15: Santa Clara County Social Vulnerability Index ..........................................................................47 Figure 16: Social Vulnerability Index Themes.............................................................................................48 Figure 17: Industry in Santa Clara County..................................................................................................50 Figure 18: Occupations in Santa Clara County...........................................................................................51 Figure 19: California and Santa Clara County Unemployment Rate27F ........................................................52 Figure 20: Modified Mercalli Intensity Scale42F..............................................................................................85 Figure 21: Peak Acceleration (%g) with 10% Probability of Exceedance in 50 Years4F .............................86 Figure 22: Historic Earthquakes in the Operational Area ...........................................................................90
Santa Clara County Multijurisdictional Hazard Mitigation Plan Table of Contents xxvii
Figure 23: Significant Known Faults in the Bay Area56F................................................................................92 Figure 24: 500-Year Probabilistic Earthquake Scenario Peak Ground Acceleration..................................94 Figure 25: Hayward Magnitude 7.0 Fault Scenario Peak Ground Acceleration .........................................96 Figure 26: Calaveras Magnitude 7.0 Fault Scenario Peak Ground Acceleration .......................................97 Figure 27: San Andreas Magnitude 7.8 Fault Scenario Peak Ground Acceleration...................................98 Figure 28: Liquefaction Susceptibility .........................................................................................................99 Figure 29: Peak Ground Acceleration with 10-percent Probability of Exceedance in 50 Years...............102 Figure 30: Highway Bridge Percentage Damage Exceeds Moderate: Calaveras Scenario.....................115 Figure 31: Hayward Fault Earthquake Scenario80F .....................................................................................119 Figure 32: Air Tanker Dropping Fire Retardant on Lick Fire in Santa Clara County86F ..............................126 Figure 33: Fire Hazard Severity Zones (FSHZ) ........................................................................................128 Figure 34: Classified Wildfire Hazard........................................................................................................130 Figure 35: Wildfire Risk to Structures .......................................................................................................131 Figure 36: Burned Hillslopes above Pulse Canyon near San Antonio Valley, SCU Lightning Complex, Santa Clara County94F.................................................................................................................................133 Figure 37: Post Fire Soil Erosion Potential ...............................................................................................135 Figure 38: NOAA Atlas Intensity - Santa Clara, California........................................................................151 Figure 39: Thunderstorm Life Cycle13F........................................................................................................153 Figure 40: National Weather Service Wind Chill Chart.............................................................................154 Figure 41: Winter Storm Severity Index ....................................................................................................155 Figure 42: National Weather Service Heat Index Chart17F..........................................................................156 Figure 43: National Weather Service Heat Index Classifications and Corresponding Effects on the Body18F ..................................................................................................................................................................156 Figure 44: The Beaufort Wind Scale12F .......................................................................................................158 Figure 45: Palmer Drought Index from January 1, 2005, to May 20, 2023129F.............................................177 Figure 46: Palmer Hydrological Drought Index from January 1, 2005, to May 20, 2023130F........................177 Figure 47: Santa Clara Valley Water District System Water Supply14F.......................................................182 Figure 48: Hetch Hetchy Water System146F..................................................................................................183 Figure 49: U.S. Drought Monitor Time Series California 2000-2023 ........................................................188 Figure 50: U.S. Drought Monitory Map of California.................................................................................189 Figure 51: Reported Number of Drought Impacts by Category156F ..............................................................190 Figure 52: CMRA Drought Hazard: Days without Precipitation Indicator for Santa Clara County ...........194 Figure 53: Tier 1 Tree Mortality High Hazard Zones162F...............................................................................197 Figure 54: Tier 2 Tree Mortality High Hazard Zones163F...............................................................................197 Figure 55: Global Temperature 1880-202217F.............................................................................................202 Figure 56: Global Carbon Dioxide Concentrations Over Time174F................................................................203 Figure 57: Impacts of Climate Change on Human Health190F ......................................................................207 Figure 58: Location of Dams Impacting Santa Clara County21F..................................................................235 Figure 59: Dam Inundation Depth Grids ...................................................................................................236 Figure 60: Levees in Santa Clara County23F ...............................................................................................237 Figure 61: Risk Rating 2.0: Project Premium Changes for Santa Clara County24F.....................................263 Figure 62: CRS Communities by Class Nationwide as of October 2022245F................................................264 Figure 63: Watersheds in the Operational Area256F......................................................................................269 Figure 64: Mapped Flood Hazard Areas in the Operational Area.............................................................274 Figure 65: 100-Year Floodplain Area Land Cover26F ..................................................................................297 Figure 66: Common Types of Landslides .................................................................................................314 Figure 67: Typical Debris Avalanche Scar and Track27F.............................................................................315 Figure 68: A Santa Clara County Debris Flow Triggered by Winter Storms Following the Loma Fire, 201728F ..................................................................................................................................................................326 Figure 69: SCVWD Historic Groundwater Conditions284F.............................................................................327 Figure 70: Deep-Seated Landslide Susceptibility in Santa Clara County.................................................329 Figure 71: Potential Tsunami Travel Times in the Pacific Ocean, In Hours291F ...........................................342 Figure 72: Tsunami Hazard Area..............................................................................................................344 Figure 73: Weapon Types Used in Terrorist Events in California310F...........................................................364 Figure 74: Targets of Terrorist Attacks in California31F ...............................................................................365 Figure 75: Highly Populated Areas with Hazardous Material Incidents Within Santa Clara County32F .....371
Santa Clara County Multijurisdictional Hazard Mitigation Plan Table of Contents xxviii
Figure 76: Gas and Hazardous Liquids Pipelines in Santa Clara County325F ..............................................374 Figure 77: Santa Clara COVID Cases 2020–202335F .................................................................................385 Figure 78: Weekly Percentage of Emergency Department Visits for Influenza-Like Illness in Santa Clara County, 2019, to February 22, 202334F .......................................................................................................388 Figure 79: Sample of Public Survey Advertisement ................................................................................. A-1 Figure 80: Sample Public Feedback on Hazard Impacts - Gilroy Meeting ............................................. A-14 Figure 81: Sample Public Feedback on Hazard Impacts - Campbell Meeting ....................................... A-15 Figure 82: Sample In-Person Feedback Option - Gilroy Meeting........................................................... A-16
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 1: Introduction to Hazard Mitigation Planning 1 1 Introduction to Hazard Mitigation Planning
1.1 Why Prepare This Plan?
1.1.1 The Big Picture
Hazard mitigation is a key component of community resilience. There is no one definition of resilience; however, the Urban Sustainability Directors Network defines resilience as the ability of people and their communities to anticipate, accommodate and positively adapt to or thrive amidst changing climate conditions and hazard events.0F0F
1 The Federal Emergency Management Agency (FEMA) defines hazard mitigation as any sustainable action that reduces or eliminates long-term risk to people and property from future disasters.1F1F
2 It involves long- and short-term actions implemented before, during, and after disasters.
Hazard mitigation activities include planning and regulations, structure and infrastructure projects, natural system protection, and education and awareness programs as well as other steps to reduce the impact of hazards.
For many years, federal disaster funding focused on relief and recovery after disasters occurred, with limited funding for hazard mitigation planning in advance. The Disaster Mitigation Act (DMA; Public Law 106-390), passed in 2000, shifted the federal emphasis toward planning for disasters before they occur.2F2F 3 The DMA requires state and local governments to develop hazard mitigation plans as a condition for federal disaster grant assistance. Regulations developed to fulfill the DMA’s requirements are included in Title 44 of the Code of Federal Regulations (44 CFR).
FEMA advocates for a “whole community” approach to hazard mitigation. This approach calls for everyone, from private property owners to commercial interests to nonprofits and local, state, and federal governments to be involved in preparing the nation for the next disaster event. By going through the local planning process outlined in the DMA, communities are able to articulate their needs for mitigation more easily. based on their understanding of their capabilities and risk. This can enhance their ability to develop projects and take mitigation actions, resulting in faster allocation of funding and more costeffective risk-reduction projects.
The DMA also promotes sustainability in hazard mitigation. To be sustainable, hazard mitigation needs to incorporate sound management of natural resources and consider the wider social and economic implications.
1 Urban Sustainability Directors Network. (n.d.). Resilience Hubs.
USDN%20Resilience%20Hubs%20Guidance%20Document
2 Federal Emergency Management Agency. (n.d.). Hazard Mitigation Assistance Grants. https://www.fema.gov/grants/mitigation#:~:text=FEMA%27s%20hazard%20mitigation%20assistance%20provides%2 0funding%20for%20eligible,cycle%20of%20disaster%20damage%2C%20reconstruction%20and%20repeated%20da mage.
3 Federal Emergency Management Agency. (2020, October 19). The Disaster Mitigation Act of 2000. https://www.fema.gov/blog/disaster-mitigation-act-2000-20-years-mitigation-planning
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 1: Introduction to Hazard Mitigation Planning 2 To further enhance the planning process and the guidelines set by DMA, the Santa Clara County Office of Emergency Management follows a specific emergency management planning process. This locally developed process incorporates various nationally recognized best practices and concepts, like the whole community planning approach, with standard program management principles that can be easily integrated into the County’s existing governmental structure. This process brings together stakeholders, builds lasting community relationships, and results in a stronger and more comprehensive mitigation plan.
This process is key to building community resilience and was followed in the 2023 MJHMP update.
1.1.2 Purposes for Planning
Hazard mitigation planning is the foundation for mitigation investments. Hazard mitigation plans are required to be updated, approved, and adopted every five years in order to maintain eligibility for multiple federal mitigation grant programs. Through the update process, mitigation actions are developed as a part of a community-based, risk-informed decision-making process.3F3F 4 Fourteen jurisdictions and three special districts within the Santa Clara County Operational Area (OA)— defined as the unincorporated county, incorporated jurisdictions, and special districts within the geographical boundaries of Santa Clara County—participated in the Multijurisdictional Hazard Mitigation Plan (MJHMP) prepared in 2023 by the Santa Clara County Office of Emergency Management with support from the consulting firm IEM. Participating jurisdictions and districts are referred to in this plan as planning partners. Elements and strategies in the MJHMP were selected because they meet a program requirement and because they meet the needs of the planning partners and their residents. One of the benefits of multijurisdictional planning is the ability to pool resources and support partnerships to reduce redundant activities within the OA that have similar risk exposure and vulnerabilities. FEMA encourages multijurisdictional planning under its guidance for the DMA. This MJHMP will help guide and coordinate mitigation activities throughout the OA. Additionally, it was developed to meet the following objectives:
Meet or exceed requirements of the DMA.
Comply with the requirements outlined in FEMA’s Local Mitigation Policy Planning Guide (April 2022), the requirements of which apply to all plans seeking agency approval on or after April 19, 2023.
Enable all planning partners to continue using federal grant funding to reduce risk through mitigation.
Meet the planning requirements of FEMA’s Community Rating System (CRS), allowing planning partners that participate in the CRS program to maintain or enhance their CRS classifications. Utilize EMAP standards for strategic planning.
Coordinate existing plans and programs so high priority projects to mitigate possible disaster impacts have an increased opportunity to be funded and implemented.
The planning partners discussed using this plan to meet Community Rating System (CRS) requirements as well. Ultimately, it was decided that Santa Clara Valley Water will lead the development of a separate Floodplain Management Plan specifically dedicated towards this goal, allowing planning partners that participate in the CRS program to maintain or enhance their CRS classifications. Relevant information from this MJHMP will be incorporated into the Floodplain Management Plan. 4 Federal Emergency Management Agency. (2022, April 19). Local Mitigation Planning Policy Guide. https://www.fema.gov/sites/default/files/documents/fema_local-mitigation-planning-policy-guide_042022.pdf
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 1: Introduction to Hazard Mitigation Planning 3
1.2 Who Will Benefit from This Plan?
The whole community of the Santa Clara County OA—including individual and families, businesses, community and nonprofit organizations, schools and academia, and all levels of government—is the ultimate beneficiary of this MJHMP. Implementing the plan will reduce risk for those who live in, work in, and visit the OA. The plan provides a viable planning framework for natural hazards of concern for the area. Participation in development of the plan by key stakeholders helped ensure outcomes will be mutually beneficial. The resources and background information in the plan are applicable across the OA, and the plan’s goals and recommendations can lay the groundwork for the development and implementation of local mitigation activities and partnerships for years to come. Mitigation projects, particularly large projects with cascading impacts, will also benefit neighboring jurisdictions.
1.3 Contents of This Plan
This plan has been set up in two volumes so that elements that are planning partner-specific can easily be distinguished from those that apply to the overall Santa Clara County OA:
Volume 1: Volume 1 includes all federally required elements of a disaster mitigation plan that apply to the OA and the unincorporated areas of the County. This includes the description of the planning process, public involvement strategy, goals and objectives, hazard risk assessment, mitigation actions, and a plan maintenance strategy.
Volume 2: Volume 2 includes all federally required participant-specific elements, in annexes for each participating entity. It includes a description of the participation requirements established for participants in this plan.
Both volumes include elements required under federal guidelines. DMA compliance requirements are cited at the beginning of subsections as appropriate to illustrate compliance.
The following appendices provided at the end of Volume 1 include information or explanations to support the main content of the plan:
Appendix A: Public outreach information used in preparation of this update. Appendix B: Plan adoption resolutions from planning partners.
All planning partners will adopt the MJHMP once it has been reviewed by FEMA and reaches Approvable-Pending-Adoption (APA) status.
1.3.1 Emergency Management Accreditation Program (EMAP) This plan incorporates elements of the Emergency Management Standard set by the Emergency Management Accreditation Program (EMAP). A consequence analysis of the potential for detrimental impacts of hazards is included in this 2023 plan update for the EMAP. Each hazard identified in this plan is followed by the Consequence Analysis result. The methodology of this analysis and the results can be found in the Risk Assessment portion in Volume 1 of this plan.
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 2: Plan Update: What Has Changed 4
2 Plan Update: What Has Changed
2.1 The Previous Plan
Santa Clara County, 15 jurisdictions, and the Santa Clara County Fire Department were covered under the 2017 Santa Clara County Operational Area (OA)Hazard Mitigation Plan. The planning process used to develop the 2017 plan was as follows:
Definition of the planning area and establishment of a working group of participating stakeholders which oversaw all phases of the plan update.
Promotion of focused outreach to individuals identified for the working group as well as other individuals, agencies, and jurisdictions that had a vested interest in the recommendations in the hazard mitigation plan.
Development of a strategy for public involvement in the plan update which included inviting members of the public to serve on the working group, conducting a public survey, utilizing multiple media avenues, and actively identifying and involving OA stakeholders. Assessment of existing programs including plans, studies, reports and technical information and all planning and regulatory, administrative, and technical, public outreach and education, and financial capabilities of planning partners to implement hazard mitigation actions. Reevaluation of the 2010 plan update to ensure planning partners had the opportunity to provide comment.
Santa Clara Valley Water District had a 2017 Local Hazard Mitigation Plan independent of the 2017 Santa Clara County Operational Area Hazard Mitigation Plan. The district joined the OA Mitigation Plan as part of the 2023 Multijurisdictional Hazard Mitigation Plan (MJHMP) update. The Midpeninsula Regional Open Space and Santa Clara County Fire Department also joined the 2023 plan update.
2.2 Why Update?
2.2.1 Federal Eligibility
Hazard mitigation plans are updated on a five-year cycle. A jurisdiction or special district covered by a plan that has expired is not able to pursue elements of federal funding under the Robert T. Stafford Act for which a current hazard mitigation plan is a prerequisite. Title 44 of the Code of Federal Regulations (44 CFR) stipulates that hazard mitigation plans must present a schedule for monitoring, evaluating, and updating the plan. This provides an opportunity to reevaluate recommendations, monitor the impacts of actions that have been completed, and determine if there is a need to change the focus of mitigation strategies. This update meets the requirements for hazard mitigation plans in order to maintain the eligibility for federal grant funding for Planning Participants.
Additionally, on April 19, 2022, FEMA updated the Local Mitigation Planning Policy Guide. This means that all plans updated and approved after April 19, 2023, must adhere to the new mitigation planning policy requirements. The 2023 update of the Santa Clara MJHMP has incorporated all changes and is in compliance with all elements of the updated Local Mitigation Planning Policy Guide. The Santa Clara County Multijurisdictional Hazard Mitigation Plan is proud to be one of the only MJHMPs in the state to incorporate the updated guidance. Some of these elements include:
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 2: Plan Update: What Has Changed 5
Incorporating a broad range of representatives in the planning process, including organizations that support underserved communities.
Incorporating the effects of climate change and future conditions in the risk assessment. Emphasizing the importance of building codes, land use ordinances, and developmental regulations in local capabilities.
Emphasizing the alignment of FEMA related mitigation programs, such as the NFIP.
2.2.2 Plan Integration
Since the last plan update, the Santa Clara County Office of Emergency Management has worked diligently to incorporate the 2023 MJHMP into other county wide planning initiatives.
Santa Clara County Safety Element (the Safety Element): The County is undergoing the 2023 Safety Plan update, which is part of the Santa Clara County General Plan. The purpose of the Santa Clara County Safety Element is to identify and include safety considerations during the decision-making and planning process by establishing goals and policies as they relate to future developments within the County. These goals and policies aim to reduce personal injury and loss of life, prevent property destruction, and reduce environmental damage throughout the community. The Safety Element focuses on addressing potential hazards such as earthquakes, flooding, wildfire, and more. The Safety Element, which will be completed in the Fall of 2023, incorporates risk and hazard data developed during the 2017 MJHMP update. It also strategically aligns with the mitigation goals and actions from the MJHMP.
Integration between the Safety Element and the MJHMP+
ensures the County is maximizing their future funding opportunities to reduce risk in the County and comply with Assembly Bill 2140 (2006), which affords the county additional benefits under the California Disaster Assistance Act.
Santa Clara County Community Wildfire Protection Plan (CWPP): In addition, the Santa Clara County Office of Emergency Management collaborated with the Santa Clara Fire Safe Council to integrate the MJHMP and the Santa Clara County Community Wildfire Protection Plan (CWPP). The CWPP identifies potential priority areas where mitigation measures are needed to protect from wildfire the irreplaceable life, property, and critical infrastructure within the County. The CWPP directly aligns with the MJHMP mitigation strategy and provides an even more in depth look at the County’s wildfire risk.
2.2.3 Changes in Development
Hazard mitigation plan updates must reflect changes in development within the OA since the previous plan (44 CFR Section 201.6(d)(3)). The plan must describe development changes in hazard-prone areas that increased or decreased vulnerability for each planning partner since the last plan was approved. If no changes in development impacted the partner’s overall vulnerability, plan updates may validate the information in the previously approved plan. The intent of this requirement is to ensure the plan’s mitigation strategy continues to accurately address the risk and vulnerability of existing and potential development and takes into consideration possible future conditions that could impact vulnerability.
According to data from the California Department of Finance, the OA decreased in population by .5 percent between 2015 and 2022.4F4F
5 The COVIID-19 pandemic, relocation of remote workers, and rising cost of housing likely contributed to some of this change. Other large urban centers around the nation experienced similar trends during the pandemic.
5 California Department of Finance. (n.d.). Demographic Reports. https://dof.ca.gov/reports/demographic-reports/
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 2: Plan Update: What Has Changed 6
Participating planning partners have adopted General Plans that govern land-use decisions and policymaking, as well as building codes and specialty ordinances based on state and federal mandates.5F5F 6 Information on planning partner-specific changes in development is included in the participant annexes in Volume 2.
2.3 Why Update? — What is Different?
This update seeks to capitalize on some of the successes of the prior plan update, including the good participation rates and format changes. The Santa Clara County OA’s 2010 Hazard Mitigation Plan Update was prepared under the ABAG process however, the County OEM determined that the new format established in the 2017 multijurisdictional hazard mitigation plan update would be best to use moving forward as it better suits the needs and capabilities of the planning partners.
The plan update process included a greater focus on public involvement that concentrated on targeted public engagement instead of simply opening technical workshops to the public. A renewed effort was made to establish a plan maintenance and implementation protocol that clearly defines ongoing commitment to the plan’s success. Some of the major differences between the current and previous plans are as follows:
• The plan has been totally restructured as an Operational Area plan, focusing only on the geographic area of Santa Clara County. The risk assessment is not a subset of a larger regional effort. Instead, it is isolated to the Santa Clara County OA and focuses on the hazards of concern for the OA.
• The risk assessment has been prepared to best support future grant applications by providing information on risk and vulnerability that will directly support the measurement of “costeffectiveness” required under FEMA mitigation grant programs. • Newly available data and tools provide for a more detailed and accurate risk assessment using means such as FEMA’s Hazards U.S. (Hazus) Multi-Hazard computer model or new data such as FEMA’s countywide Digital Flood Insurance Rate Maps. • The planning process creates the opportunity for all municipal planning partners to prepare to meet the requirements of California Senate Bill 379 during the next plan update. That bill will require integration of quantitative climate change risk assessment in the development of climate change related initiatives as part of the safety element of general plans. • The plan is more user-friendly because it is confined to one package. • The update created an opportunity for the County of Santa Clara, local cities and towns, and other planning partners to engage citizens directly in a coordinated approach to gauge their perception of risk and support of the concept of risk reduction through mitigation. 6 San José Spotlight. (2022, April 2). Silicon Valley Residents Left in Droves During Pandemic. https://sanjosespotlight.com/silicon-valley-san-jose-santa-clara-sunnyvale-residents-left-in-droves-exodus-duringcovid-19-pandemic/
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 2: Plan Update: What Has Changed 7
• While priorities have remained the same, the plan’s goals objectives and actions are more clearly defined. The plan identifies actions rather than strategies as was the case with the prior plans. Strategies provide direction, but actions are fundable under grant programs. This plan replaces strategies with a guiding principle, goals, and objectives. The actions identified meet multiple objectives that are measurable, so that each planning partner can measure the effectiveness of its mitigation actions, which was difficult prior to this plan update.
Below is a table comparing the 2017 MHJMP and 2023 MHJMP. Changes to the plan’s format and contents involved a multistep process that included best practices research and an assessment of jurisdiction and special district planning needs.
Table 2: Summary of Changes in the 2023 MJHMP
Changes Throughout the Plan
• Comprehensive review and update of hazard history, risk and vulnerability data and information • New hazards of climate change, sea-level rise, wildfire smoke, and air quality added • Expanded outreach to vulnerable and historically underserved populations • Lens of planning for climate change and equitable outcomes used to create a comprehensive and inclusive plan
• Integrated MJHMP planning process with the planning processes of the Community Wildfire Protection Plan and Safety Element of the General Plan update • It was determined that all CRS requirements will be met in a forthcoming floodplain management plan created by Santa Clara Valley Water District
• City of Monte Sereno was not an active participant in this plan update, but is referenced in the plan as applicable
• Santa Clara Valley Water District and Midpeninsula Regional Open Space District joined as Planning Partners
• Plan was updated to meet 2023 FEMA hazard mitigation plan guidance and requirements Volume I: Base Plan
Section Changes
Section 1: Introduction to Hazard
Mitigation Planning
• Updated explanation of importance and purpose of hazard mitigation planning
Section 2: Plan Update: What Has
Changed
• Summary list of plan changes and updates included
Section 3: Planning for Climate
Change and Equitable Outcomes
• Section added to highlight Santa Clara County’s goal of continuing to integrate equity into all aspects of emergency management Section 4: Plan Update Approach • Information added to highlight the concentrated effort to ensure plan integration between the County Community Wildfire
Protection Plan and County Safety Element of the County General Plan updates as well as other approved plans
• Explanation of the ways planning partners engaged residents, particularly those who are underserved and/or socially vulnerable,
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 2: Plan Update: What Has Changed 8
Volume I: Base Plan
Section Changes
and gauged their perception of risk and support for risk reduction through mitigation
• Explanation of the ways planning partners engaged community stakeholders, particularly those that assist underserved and/or socially vulnerable, and gauged their perception of risk and support for risk reduction through mitigation
• Updated plan development chronology and milestones
Section 5: Santa Clara County
Operational Area Profile
• All information updated using the most recent data available Sections 6-16: Identified Hazards
of Concern and Risk Assessment
• The risk assessment includes further considerations of emerging hazards, like the impact of climate change, wildfire smoke, and air quality, which have recently impacted the OA with increasing frequency since the 2017 plan
• Hazard risk ranking updated and is now hazard risk index criteria • Wildfire, drought, and climate change are now considered to have higher average overall hazard risk by Planning Partners when compared to their hazard risk ranking scores in the 2017 plan • Updated and expanded information on hazard history, location, extent, frequency, and severity; exposure, vulnerability, cascading hazards, and how climate change may impact the frequency, extent, and severity of each hazard
• The risk assessment has been formatted to provide information on risk and vulnerability that will allow a measurement of costeffectiveness • Severe weather terminology updated to inclement weather • Updated maps and graphics
• Hazus data and findings updated
• The plan was developed in accordance with the most recent EMAP standards
• Latest disaster declaration data added
• High Hazard Potential Dam Grant Program (HHPD) requirements were considered and referenced
Section 17: Mitigation Strategy • Mitigation goals and objectives and criteria for mitigation action item prioritization have been updated to include climate change, resiliency, and benefits to populations that are underserved and/or socially vulnerable.
• Expanded detail on plan monitoring, evaluating, and updating to include roles and responsibilities and description of specific methods and schedules
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 2: Plan Update: What Has Changed 9
Volume 2: Planning Partner Annexes
• Each Planning Partner has a minimum of one mitigation action per a hazard that can impact them • Actions and project identified in the Santa Clara County Community Wildfire Protection Plan included in annexes, as applicable
• Expanded information about Planning Partner participation and compliance in the National Flood Insurance Program
• All data and information updated, including Local Planning Team members, jurisdiction or special district profile, capability assessment, opportunities to integrate the mitigation plan into other local planning initiatives, hazard event history, jurisdiction- or special district-specific vulnerabilities, future development trends, hazard risk index, future needs to better understand risk and vulnerability, status of previous action items, and maps.
• Mitigation successes highlighted, as applicable
• Risk and vulnerability assessment expanded to include climate change, wildfire smoke, and air quality • Local floodplain managers identified by name in each annex, as applicable • Development trends since the 2017 plan identified
• Sea-level rise map added to the City of Palo Alto’s annex Appendices
• Appendix B updated from progress report template to adoption resolutions from all participating jurisdictions.
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 3: Planning for Climate Change and Equitable Outcomes 10 3 Planning for Climate Change and Equitable
Outcomes
Local jurisdictions have a responsibility to ensure that the plan’s mitigation strategy complies with all applicable legal requirements related to civil rights, to ensure nondiscrimination. Such compliance can help achieve equitable outcomes through the mitigation planning process for all communities, including underserved communities and socially vulnerable populations.
To ensure that the planning process and outcomes of the local mitigation plan benefit the whole community, equity must be central in its development. Climate change increases the frequency, duration, and intensity of natural hazards, such as wildfires, extreme heat, drought, storms, heavy precipitation, and sea level rise. Communities are feeling the impacts of a changing climate now.
Respecting and leveraging the diversity of cultures in Santa Clara County ensures that mitigation planning is fair and equitable by applying a race and social justice framework to analyzing situations, evaluating options, and implementing solutions.
The Santa Clara County Office of Emergency Management (SCCOEM) has adopted the FEMA’s equity definition of “the consistent and systematic fair, just and impartial treatment of all individuals.” In addition, SCCOEM acknowledges that historically underserved communities and individuals are often overburdened by systemic injustices/disparities, and these are amplified during the disaster cycle including mitigation.
Therefore, the County of Santa Clara’s goal is to continue integrating equity into all aspects of emergency management by:
Leveraging the Access and Functional Needs (AFN) and Cultural Competency Working Group that regularly meets with members of the entire Operational Area, including the community. Involving members from a variety of groups represent the diverse community living in the County, as well as representatives from historically marginalized groups in the planning process. Conducting outreach events that focus on the county’s diverse population and most vulnerable community members like people with access and functional needs. Providing multilingual outreach and communication to residents of the County. Adopting Communication, Maintaining Health, Independence, Safety, Support Services, and SelfDetermination, and Transportation (C-MIST) Framework. C-MIST is a function-based perspective composed of the five (5) functions that delineate areas where preparedness intervention can reduce disaster vulnerability and risk to the whole community. Building, engaging, and sustaining partnerships with groups that have experienced inequities. For example, individuals experiencing communication, health, independence, safety, support services, self-determination, and transportation barriers during disasters. Developing assessments and plans that prioritize assistance to those with the greatest needs and include vulnerable populations in the planning process. Identifying needs and assets, as well as pre-existing vulnerability and resilience. All community members can exercise their agency through free and informed choice(s).
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 3: Planning for Climate Change and Equitable Outcomes 11 Through these strategies, SCCOEM will continue to lay the foundation for closing gaps identified through lessons learned from previous EOC activations such as COVID-19, Wildfires, and Inclement Weather Episodes, and Active Shooter events that have impacted Santa Clara County.
Mitigation decisions and actions strive to provide benefit for all residents equally. SCCOEM Mitigation Program is designed to identify and remove social and institutional barriers that hinder or preclude people with disabilities and all those in the community historically subjected to unequal treatment from full and equal enjoyment of the programs, goods, services, activities, facilities, privileges, advantages, and accommodations provided. Additionally, during mitigation planning and applying for mitigation funding, the County will identify opportunities to increase equity and create new opportunities for the post-disaster state of the County.
An equitable community mitigation rests on the foundation of a “complete community” that applies equitable and fair practices in all the County’s planning and implementation. The concept demonstrates local government’s commitment to inclusion and fairness while managing a recovery process that links regional, state, and federal practices.
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 4: Plan Update Approach 12
4 Plan Update Approach
This plan update process had the following primary objectives:
Secure grant funding.
Form a planning group.
Identify stakeholders.
Establish a planning partnership.
Define the Santa Clara County OA.
Identify and coordinate with other agencies involved in hazard mitigation activities. Review and integrate existing plans, policies, and programs. Engage the public.
These objectives are discussed in the following sections.
4.1 Grant Funding
This planning effort was supplemented by a FEMA Hazard Mitigation Grant Program (HMGP) grant under DR-4569 California Wildfires. The County of Santa Clara Office of Emergency Management (OEM) was the sub-applicant for the grant. OEM applied in 2021 and was awarded the grant in 2022. It covered 75 percent of the cost for the development of this plan.
4.2 Formation of the Core Planning Team
Santa Clara County OEM hired IEM to assist with the development and implementation of the plan. The lead IEM planner reported directly to the Santa Clara County Operational Area Mitigation Program Manager and the project manager for the plan update. Meetings were held on a weekly and biweekly basis to discuss the plan update status, outreach and engagement strategies, and planning milestones. A Core Planning Team was formed to lead the planning effort, made up of the following members:
Santa Clara County Office of Emergency Management
Santa Clara County Office of Sustainability
Santa Clara County Department of Planning and Development IEM
This planning team—designated the Santa Clara County Operational Area Multijurisdictional Hazard Mitigation Plan (MJHMP) Core Planning Team (or the Core Planning Team)—coordinated regularly over the course of this project to track plan development milestones, brainstorm outreach and engagement strategies, and identify meeting content to help with development of the update. The Core Planning Team also consisted of members of the County Safety Element update, ensuring visibility between plans.
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 4: Plan Update Approach 13
4.3 Defining Stakeholders
For this planning process, “stakeholder” was defined as: any person or public or private entity that owns or operates facilities that would benefit from the mitigation actions of this plan, and/or has an authority or capability to support mitigation actions identified by this plan. This includes, but is not limited to, local and regional agencies involved in hazard mitigation activities, agencies that have the authority to regulate development, neighboring communities, representatives of businesses, academic, and other private organizations such as those that sustain community lifelines, and representatives of nonprofit organizations including community-based organizations that work directly with and/or provide support to underserved communities and socially vulnerable populations.
For the sake of clarity, when developing outreach materials, stakeholders were separated into two categories:
Internal Stakeholders: Stakeholders identified and engaged by participants to enhance the planning process and the update of the MJHMP. These stakeholders are subject matter experts within the participating jurisdictions or special districts who impact or may be impacted by a mitigation action or policy. This included people in positions who had the authority to regulate development of the plan. These stakeholders informed the planning teams about specific topics and offered different points of view while providing data, reviewing the MJMP draft, attending planning workshops, and advocating for mitigation measures. Internal stakeholders for each planning partner are identified in the participant annexes in Volume 2. External Stakeholders: Planning partners identified stakeholders outside their jurisdiction or special district who impact or can be impacted by a mitigation action or policy. These stakeholders were not necessarily involved in all stages of the planning process, but as subject matter experts, they informed the planning teams on specific topics and offered different points of view while providing data, reviewing the MJHMP draft, and advocating for mitigation measures.
At the beginning of the planning process, planning partners identified a list of stakeholders to engage during the development of the Santa Clara County Operational Area Hazard Mitigation Plan. The following stakeholders were invited to play a role in the planning process via email:
Table 3: External Stakeholders Invited to Be Involved in Planning Process Agency or Organization Point of Contact
American Red Cross Ann Herosy, Disaster Services
American Red Cross – Silicon Valley Chapter Ginny Ortiz, Disaster Program Manager Amateur Radio Emergency Service (ARES) Barton Smith, Coordinator Avenidas John Sink, Vice President
CADRE - Collaborating Agencies’ Disaster Relief
Effort
Marsha Hovey, Executive Director
California Office of Emergency Services (Cal
OES)
Victoria LaMar-Haas, Chief, Mitigation Planning
Division
Cal OES Brian Buckhout, Emergency Services Coordinator
California Department of Forestry and Fire
Protection
Edgar Orre, Division Chief
California Department of Transportation Shawn Casteel, Acting Senior Environmental Supervisor
Campbell Community Emergency Response
Team
Mark Dunkle, President
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 4: Plan Update Approach 14
Agency or Organization Point of Contact
Campbell Union School District Rosana Palomo, Director, Student Services Cattlemen’s Association Brent Kirk, President
City of East Palo Alto Melvin Gaines, City Manager
City of Menlo Park Justin Murphy, City Manager
Cooper-Garrod Estate Vineyards Bill Cooper, Vintner
Cupertino Sanitation District Benjamin Porter, District Manager Department of Homeland Security Staff, Transportation Security Administration Coordination Center
Department of Toxic Substances Claude Jemison, Regulator for Los Lagos Golf Course and SAP Center (former landfill and
cleanup site)
Department of Toxic Substances Sagar Bhatt, Regulator for Watson Park (former landfill)
Department of Toxic Substances Jovanne Villamater, Regulator for Vista Montana Parks
Department of Toxic Substances Julie Pettijohn, Manager for all regulatory sites except Watson Park
Downtown Streets Team Jim Rettew, Interim Executive Director Emergency Medical Services Michael Cubano, Duty Chief
Emergency Services Volunteer Representative Annette Glanckopft, Volunteer Emergency Services Volunteer Representative Esther Nigenda, Volunteer Federal Aviation Administration David Zakaski, Airport Tower Manager Fellowship Plaza Shreya Shah, Senior Project Manager
Foothill - De Anza Community College District Simon Pennington, Associate Vice President, College and Community Relations, Marketing, and
Communications
Foothill - De Anza Community College District Joel Cadiz, Executive Director, Facilities Foothill - De Anza Community College District
Police Department
Daniel Acosta, Police Chief
Gavilan College Jaime Mata, Interim Vice President,
Administrative Services
Gilroy Unified School District Aurelio Rodriguez Coordinator, Safety and Emergency Preparedness
Gilroy/Hollister California Highway Patrol Phil Cooper, Captain Google Katherine Williams, Corporate Communications
Hidden Villa farm Lukas Wiborg, Assistant Property Manager Intel Corporation Stacy Sher, Crisis Manager
Kaiser Permanente—Santa Clara Brendan Gadd, Safety Specialist Kaiser Permanente—Santa Clara Charles L. Smith, Support Services Administrator Life Moves Philip Dah, Opportunity Center Manager
Loma Prieta Volunteer Fire Department Alex Leman, Chief Los Altos Hills County Fire District J. Logan, General Manager
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 4: Plan Update Approach 15
Agency or Organization Point of Contact
Los Altos Hills County Fire District Captain (Ret.) Denise Gluhan Los Altos Hills County Fire District Eugenia Woods, Programs, Planning and Grants Manager
Los Altos School District Erik Walukiewicz, Assistant Superintendent, Business Services
Loma Prieta Resource Conservation District Dina Iden, Executive Director Morgan Hill Unified School District Carmen Garcia, Superintendent Moffett Field Ames Research Center, National
Aeronautics and Space Administration (NASA)
Anastasiya Maynich, Emergency Management
Specialist
National Weather Service, National Oceanic and
Atmospheric Administration (NOAA)
Brian Garcia, Meteorologist
Pacheco Pass Water District Neelima Palacherla, Executive Officer Palo Alto Chamber of Commerce Charlie Weidanz, Executive Director Palo Alto Medical Foundation Richard Stilleke, Director, Environmental Health and Safety
Palo Alto Planning and Transportation
Commission
Doria Summa, Vice Chair
Palo Alto Unified School District Mike Jacobs, Emergency Manager Pacific Gas and Electric (PG&E) Kevin Conant, Senior Public Safety Specialist Purissima Water District Phil Witt, General Manager
Purissima Water District Anthony Stoloski, Operations Manager Ravenswood Family Health Center Daisy Garcia, Associate, Disaster Preparedness and Project Management
Regional Water Quality Control Board Ava Castanha, Regulator, Environmental Innovation Center
Regional Water Quality Control Board Celina Hernandez, Regulator, Fire Training Regional Water Quality Control Board Alyx Karpowicz, Regulator, Roberts and Story Road Landfills
Regional Water Quality Control Board Vic Pal, Regulator, Singleton Landfill Rotating Safe Car Park Norman Puck, Program Director
San Francisquito Creek Joint Powers Authority Margaret Bruce, Executive Director San José Water John Tang, Vice President, Regulatory Affairs and Government Relations
Santa Clara County CERT President
Santa Clara County FireSafe Council Seth Schalet, Chief Executive Officer Santa Clara County FireSafe Council Amanda Brenner, Program Director, Hazardous Fuel Reduction
Santa Clara County FireSafe Council Dede Smullen, 2nd Vice President Santa Clara County Local Oversight Program Gerald O’Regan, Regulator for Fire Training Santa Clara County Local Oversight Program Joe Muzzio, Regulator for Fire Station at 1138 Olinder Road
Santa Clara County Local Oversight Program Shalom Marquardt, Regulator for Fire Station 8
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 4: Plan Update Approach 16
Agency or Organization Point of Contact
Santa Clara County Parks Don Rocha, Director
Santa Clara County Planning & Development Samuel Gutierrez, Principal Planner Santa Clara County Planning & Development Michael Alvarez, Deputy Director Santa Clara County Sheriff’s Office Neil Valenzuela, Commander, West Valley Patrol Division
Santa Clara University Tyler Masamori, Emergency Planning Manager Santa Clara Valley Open Space Authority Derek Newman, Manager, Field Operations Santa Clara Valley Open Space Authority Megan Robinson, Supervising Open Space Technician
Santa Cruz County David Reid, Director, Office of Emergency Management
Saratoga Amateur Radio Association Jack Griswold, President Saratoga Area Senior Coordinating Council Tylor Taylor, Executive Director Saratoga CERT Charles Rader, Volunteer Lead
Saratoga Fire Protection District Commissioner Joseph Long Jr.
Saratoga Fire Protection District Commissioner Ernest Kraule Saratoga Fire Protection District Commissioner Eugene Zambetti Saratoga Fire Protection District Trina Whitley, Business Manager Saratoga Retirement Community Sarah Stel, Executive Director Silicon Valley Animal Control Authority (SVACA) Heidi Springer, Executive Assistant Silicon Valley Clean Energy Girish Balachandran, Executive Director San José Fire Department, San José Mineta
International Airport
Brendan Buller, Battalion Chief
San José Police Department, San José Mineta
International Airport
Jason Pierce, Lieutenant
Spring Valley Volunteer Fire Department Mike Hacke, Chief St. Louise Hospital (Santa Clara County Hospital
System)
Geoff Tull, Emergency Management Coordinator
Stanford Healthcare Kathy Harris, Emergency Manager
Stanford Healthcare Laura Jackson, Senior Manager, Office of Emergency Management
Stanford Healthcare Monica Plumb, Project Coordinator, Office of Emergency Management
Stanford Healthcare Taylor Wyatt, Project Coordinator, Office of Emergency Management
Stanford University Cody Hill, Associate Director, Stanford Resiliency and Emergency Response
Stanford University Board of Trustees Staff, Board of Trustees Office Stanford University Office of Emergency
Management
Keith Perry, Assistant Director and Emergency
Manager
Stanford University, IT Facilities, Infrastructure,
and Resilience
Matthew Ricks, Senior Director
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 4: Plan Update Approach 17
Agency or Organization Point of Contact
Stanford University, Water Resources and Civil
Infrastructure
Tom Zigterman, Senior Director
Stanford University/Real Estate Mark Smith, Manager
Stanford University/Real Estate Ramsey Shuayto, Director, Asset Management The Villas Scott Clawson, Manager
Valley Water Flood Information Team Greg Meamber, Senior Engineer Vista Center for the Blind and Visually Impaired Karae Lisle, Chief Executive Officer West Valley Clean Water Program Authority Sheila Tucker, Executive Director West Valley College Stephanie Kashima, President
West Valley Sanitation District Jon Newby, District Manager Westwind Barn Tori Dye, Barn Manager
4.4 Establishment of the Planning Partnership
Santa Clara County OEM opened this planning effort to all eligible local governments and special districts within the OA. Each jurisdiction or special district wishing to join the planning partnership was asked to provide a “letter of intent to participate” that designated a point of contact and confirmed the organization’s commitment to the process and understanding of expectations. All planning partners provided this letter of intent. The planning partners covered under this plan are listed below.
Table 4: Planning Partner Main Points of Contact
Planning Partner Main Point of Contact
County of Santa Clara Dr. Parastou Najaf, Senior Emergency Manager – Mitigation/Recovery, Santa Clara County Office of Emergency Management
City of Campbell Dan Livingston, Captain of Support Services Division, Police Department
City of Cupertino Meredith Gerhardt, Emergency Management Analyst, Office of Emergency Management
City of Gilroy Andrew Young, Emergency Services and Volunteer Coordinator, Office of Emergency Services
City of Los Altos Kathryn Krauss, Captain of Operations, Police Department Town of Los Altos Hills Ann Hepenstal, Emergency Preparedness Consultant, Town of Los Altos Hills
Town of Los Gatos Nicolle Burnham, Director, Parks and Public Works Department
City of Milpitas Toni-Lynn Charlop, Manager, Office of Emergency Services City of Morgan Hill Jennifer Ponce, Coordinator, Office of Emergency Services City of Mountain View Robert Maitland, Emergency Services Coordinator, Office of Emergency Services
City of Palo Alto Nathaniel Rainey, Emergency Services Coordinator, Office of Emergency Services
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 4: Plan Update Approach 18
Planning Partner Main Point of Contact
City of San José Jay McAmis, Deputy Director, Office of Emergency Management
City of Santa Clara Jennifer Guzman, Emergency Management Analyst, Office of Emergency Services
City of Saratoga Crystal Bothelio, Assistant City Manager, City Manager’s Department
City of Sunnyvale Daniel Moskowitz, Lieutenant, Office of Emergency Services, Department of Public Safety
Midpeninsula Regional Open Space
District
Brandon Stewart, Land and Facilities Department Manager, Midpeninsula Regional Open Space District
Santa Clara County Fire Department Louay Toma, Senior Emergency Manager, Santa Clara County Fire Department
Santa Clara Valley Water District Juan Ledesma, Program Administrator Supervisor, Office of Emergency Services
One-on-one planning meetings were held with planning partners throughout the planning process. A total of 43 individual meetings were held with plan participants to gather information and to provide guidance for the jurisdictions and special districts throughout the planning stages. Each meeting is described in Table 5.
Table 5: One-on-One Meetings with Planning Partners
Planning Partner Date Discussion Topic(s)
City of Campbell February 13, 2023 Planning process contacts Capabilities assessment
May 15, 2023 Planning documentation review
City of Cupertino February 6, 2023 Planning process contacts Capabilities assessment
April 20, 2023 Mitigation strategy
City of Gilroy February 14, 2023 Planning process contacts Capabilities assessment
City of Los Altos February 14, 2023 Planning process contacts Capabilities assessment
April 27, 2023 Capabilities assessment
Mitigation strategy
May 9, 2023 Planning documentation review
City of Milpitas March 17, 2023 Planning process contacts Capabilities assessment
Risk assessment
May 1, 2023 Risk assessment
Mitigation strategy
City of Morgan Hill February 14, 2023 Planning process contacts Capabilities assessment
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 4: Plan Update Approach 19
Planning Partner Date Discussion Topic(s)
City of Mountain View January 31, 2023 Planning process contacts Capabilities assessment
March 15, 2023 Risk assessment
April 13, 2023 Mitigation action items
May 1, 2023 Mitigation strategy
City of Palo Alto February 7, 2023 Planning process contacts Capabilities assessment
Planning process timeline
City of Santa Clara February 8, 2023 Planning process contacts Capabilities assessment
Planning process timeline
March 16, 2023 Risk assessment with local planning team March 17, 2023 Risk assessment with water and sewer team March 26, 2023 Mitigation strategy
May 10, 2023 Planning documentation review
City of San José February 13, 2023 Planning process contacts Capabilities assessment
April 27, 2023 Capabilities assessment
Mitigation strategy
May 16, 2023 Planning documentation review
City of Saratoga February 9, 2023 Planning process contacts Capabilities assessment
March 14, 2023 Risk assessment
City of Sunnyvale January 26, 2023 Planning process contacts Capabilities assessment
March 3, 2023 Risk assessment
April 7, 2023 Risk assessment
Mitigation strategy
Midpeninsula
Regional Open
Space District
March 6, 2023 Planning process contacts
Capabilities assessment
Risk assessment
Planning process timeline
Santa Clara County
and Santa Clara
County Fire
Department*
February 10, 2023 Planning process contacts
Capabilities assessment
March 2, 2023 Planning process contacts
Capabilities assessment
March 8, 2023 Capabilities assessment
Risk assessment
March 28, 2023 Capabilities assessment
Risk assessment
Mitigation strategy
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 4: Plan Update Approach 20
Planning Partner Date Discussion Topic(s)
Santa Clara Valley
Water District
January 23, 2023 Annex layout and contents
Community Rating System
February 21, 2023 Community Rating System
March 13, 2023 Community Rating System
April 21, 2023 Mitigation strategy
GIS and mapping
Town of Los Altos
Hills
March 17, 2023 Risk assessment
April 25, 2023 Risk assessment
Mitigation strategy
June 20, 2023 Annex draft review
Town of Los Gatos February 13, 2023 Planning process contacts Capabilities assessment
April 27, 2023 Capabilities assessment
Mitigation strategy
*Santa Clara County and Santa Clara County Fire Department held meeting together due to shared staff and resources.
Figure 1: Planning Partners Meeting
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 4: Plan Update Approach 21
Figure 2: Planning Partners Mitigation Strategy Meeting
4.5 Defining the Planning Area
The defined planning area for this update has been defined as the Santa Clara County Operational Area (OA). The OA is defined as the unincorporated county and incorporated cities within the geographical boundary of Santa Clara County. Relevant OA characteristics are described in Section 5. The City of Monte Sereno did not actively participate in this MJHMP and does not have a planning partner annex; however, information and data related to the city are included throughout the plan as appropriate and relevant.
4.6 Review of Existing Programs
Hazard mitigation planning must include review and incorporation, if appropriate, of existing plans, studies, reports, and technical information (44 CFR, Section 201.6(b)(3)). Section 5.9 of this plan provides a review of laws and ordinances in effect within the OA that can affect hazard mitigation actions. In addition, the following programs can affect mitigation within the OA:
California Fire Code.
2016 California Building Code.
California State Hazard Mitigation Forum.
Local Capital Improvement Programs.
Local Emergency Operations Plan.
Local General Plans.
Housing Element.
Safety Element (prior and 2023 draft components).
Community Wildfire Protection Plan (2016 version and components of the 2023 draft). Local Zoning Ordinances.
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 4: Plan Update Approach 22
Local Coastal Program Policies.
An assessment of all planning partners’ regulatory, technical, and financial capabilities to implement hazard mitigation actions is presented in the individual planning partner-specific annexes in Volume 2.
Many of these relevant plans, studies and regulations are cited in the capability assessment.
4.7 Public Involvement
Broad public participation in the planning process helps ensure that diverse points of view about the OA’s needs are considered and addressed. Additionally, the plan must document how the public had an opportunity to be involved in the planning process, including underserved communities and vulnerable populations within the planning area were provided an opportunity to be involved. The public must have opportunities to comment on disaster mitigation plans during the drafting stages and prior to plan approval (44 CFR, Section 201.6(b)(1)).
4.7.1 Strategy
The planning team developed a robust public outreach process within the very short project timeline, attempting to reach as many Santa Clara County community members and stakeholders as possible through the following activities:
Development of a public outreach plan approved by the Core Planning Team. Partner with planners updating the Safety Element and Community Wildfire Protection Plan planning processes to expand public outreach efforts.
Attendance at advertised public outreach events and virtual meetings with live interaction. Development and advertisement of a public survey posted on the SCCOEM’s webpage to collect pertinent information from residents and the business community. Publication of the survey in Santa Clara County’s most spoken languages: English, Spanish, Chinese, Tagalog, and Vietnamese.
Use of social media, such as Nextdoor, Facebook, and Twitter to publicize the survey.
Stakeholder Outreach
Stakeholders are the individuals, departments, agencies, and jurisdictions that have a vested interest in the recommendations of the hazard mitigation plan. The effort to include stakeholders in this process included stakeholder participation on the Steering Committee. The following federal, state, regional, and local stakeholders also played a role in the planning process:
FEMA Region IX provided planning guidance throughout the planning process. The California Office of Emergency Services (Cal OES) provided planning guidance throughout the planning process. Cal OES also reviewed the draft and final version of the MJHMP as part of the hazard mitigation planning process required by DMA. Many local external stakeholders, including state agencies, local agencies, universities, and nonprofit organizations, were given the opportunity to review the draft plan and provide input. A list of these stakeholders is included in Table 3.
The strategy to involve the public and external stakeholders in this plan include the following:
Utilize a survey to determine if the public’s perception of risk and support of hazard mitigation has changed since the initial planning process.
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 4: Plan Update Approach 23
Utilize social media and local media to share information about the MJHMP process and inform OA citizens about opportunities to participate.
Identify and involve a comprehensive range of OA stakeholders. Partner with planners updating both the Safety Element and the Community Wildfire Protection Plan to expand public outreach efforts.
Public Survey
The planning team relied on the community survey (available in English, Spanish, Tagalog, Chinese, and Vietnamese) as the primary method for gathering information and feedback from the public. The secondary method was multiple in-person combined planning meetings which participants were introduced to hazard mitigation and invited to take the survey. The survey was approved by the Core Planning Team and was available to complete via the Santa Clara County Office of Emergency Management’s website. Flyers were also posted around the County and on participating jurisdiction’s official websites and social media pages.
Figure 3: Picture of Public Survey Announcement
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 4: Plan Update Approach 24
Figure 4: Public Survey Media Announcement
The survey included 35 questions to:
Gauge the public’s perception of risk and identify what citizens are concerned about; Identify the best ways to communicate with the public; Determine the level of public support for the different mitigation strategies; and Understand the public’s willingness to invest in hazard mitigation.
Social Media
At the beginning of the plan development process, a website hosted on the Santa Clara County OEM main website was utilized to keep the public posted on plan development milestones and to solicit relevant input. The website was publicized in all press releases and public meetings. Information on the plan development process, the survey, and phased drafts of the plan was made available to the public on the site throughout the process. Santa Clara County OEM intends to keep a website active after the plan’s completion to keep the public informed about successful mitigation projects and future plan updates.
The website can be accessed at this link: https://emergencymanagement.sccgov.org/multijurisdictional-hazard-mitigation-plan-mjhmp.
Many of the participating local jurisdictions also promoted the website on social media and used social media platforms to share public meeting information, notice of the public survey, and notice of the public comment period. Valley Water, for example, posted to Twitter five times and Facebook 4 times as part of a multi-prong strategy. An example of the social media outreach is provided below.
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 4: Plan Update Approach 25
Figure 5: City of Campbell Social Media Outreach
Local Media and Press Releases
The Planning Team conducted a wide range of outreach activities in local media. The County developed three key messages to highlight the significance of the Public Survey Period:
1. Announcement of the Public Survey Period: Informing the community about the survey’s availability.
2. Planning for the Future: Emphasizing the importance of proactive hazard mitigation planning.
3. Your Participation Matters: Encouraging community members to participate and contribute to the planning process by taking the survey.
During the Public Survey Period for the MJHMP, Santa Clara County disseminated one press release to the various media outlets and utilized a specific media monitoring service to report media coverage for the MJHMP. Unfortunately, despite the County’s best efforts, no major media outlets covered the event.
However, Sing Tao Dailey, a prominent Chinese media outlet, published the information on their website on April 17, 2023. This media outlet boasts a wide-reaching presence across the United States, maintaining offices in major markets which includes New York, Los Angeles, and San Francisco. The press release was also published to the Office of Emergency Management’s website as part of the Newsroom page.
Valley Water also reached out to communities via local media, including Chinese News, El Observador, Murcury News, Metro, Nextdoor, and Vietnam Daily.
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 4: Plan Update Approach 26
Information was posted to the County’s social media sites including Facebook, Instagram, Twitter, as well as the Department of Planning and Development’s website and the County’s main website during the public survey period. To amplify public messaging, the County encouraged key stakeholders, including the Operational Area Joint Information System, the Access and Functional Needs & Cultural Competency Work Group, and the Operational Area Emergency Managers to amplify messaging with their served community members.
To simplify access to the survey and increase participation, the County established a user-friendly vanity URL. This URL received significant traction, directing 74% of community members to the Hazard Mitigation Webpage, resulting in 880-page views and 767 visits. Additionally, 81% of users who accessed the Hazard Mitigation Page were successfully redirected to the actual survey page. The Hazard Mitigation page was the second most popular site for the period.
The strategic use of local communication channels successfully enhanced community engagement, ensuring a more robust Multi-Jurisdictional Hazard Mitigation Plan.
Joint MJHMP Outreach
Plan integration was considered throughout the development of a public outreach approach for this plan update. As the Safety Element was being updated at the same time as the Santa Clara County Operational Area HMP, the Core Planning Team members coordinated to include hazard mitigation planning components during outreach for the Safety Element. At this meeting, members of the public were presented with interactive boards and polling questions to gauge their hazard concerns, personal preparedness measures, public outreach and education needs, and support for common infrastructure enhancements. The Hazard Mitigation Plan update was discussed, and the public was provided with information on hazard mitigation and hazard mitigation planning including a link to the public survey. This meeting was conducted at the Campbell Community Center, targeting vulnerable populations in the City of San Jose and central Santa Clara valley. The county geographically designed this approach to ensure that those residence who could not travel to the South County community outreach event in Gilroy (mentioned below) still had an opportunity to have their voices heard. Valley Water had staff representation in the audience to respond to and capture inquiries pertaining to Valley Water’s jurisdictions. More than 40 residents from across the county, including vulnerable pockets in the City of San Jose and the Santa Cruz mountain range, interacted and worked with the MJHMP to voice their concerns.
In determining which vulnerable communities to target for outreach, planning partners referenced the California Hazard Exposure and Social Vulnerability map, Figure 6 below. Two underserved or socially vulnerable communities were identified according to their estimated hazard exposure and social vulnerability. The largest area in San Jose is east of Highway 87 and a much smaller area is in South Santa Clara County, specifically the City of Gilroy. In addition, by using the CalEMA GIS dashboard, these two areas are also recognized for having a median household income of less than 80% of the statewide average and for having significant earthquake ground shaking potential.
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 4: Plan Update Approach 27
Figure 6: Hazard Exposure and Social Vulnerability Map for Santa Clara Valley The County also actively facilitated meetings and coordinated outreach between the team working on the HMP and the Community Wildfire Protection Plan (CWPP). Like the HMP, the CWPP includes recommendations for mitigation measures across the OA. It also includes annexes for the many of the same planning partners which highlight their unique wildfire history and considerations. These similarities presented a valuable opportunity for the two teams to solicit input from the public together. Four joint inperson Public Outreach meetings were conducted in remote, access and functional needs (AFN) areas of the incorporated County as well as an in-person meeting in the Gilroy/South County area where there are pre-identified vulnerable populations. All were welcome to attend. For those that could not make it in person, an additional online outreach meeting was held.
Draft Plan Final Public Comment Period
A public comment period was conducted to allow the public to provide feedback on the proposed draft of the plan prior to submittal to Cal OES for pre-adoption review and approval. This public comment period ran for 14 days from July 14 to July 28, 2023. The draft plan was shared by participating jurisdictions via their social media sites and emails to external stakeholders. The posted plan was accompanied by a narrative explaining to the public the purpose and content of the plan and was available to view on the County’s website.
The Planning Team received 17 comments from the public during the comment period. These comments were reviewed by the Planning Team and incorporated in the plan as appropriate.
4.7.2 Public Involvement Results
Survey Results
The survey received 588 responses. There were 576 responses to the English survey, 10 responses to the Chinese survey, and 2 responses to the Spanish survey. The use of multi-lingual outreach material proved to be valuable in providing the opportunity for more participation and in receiving a
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 4: Plan Update Approach 28
broader range of feedback. The results of the survey were presented to the planning partners and will be used in all future decisions making regarding mitigation, risks, and hazards. The survey results regarding respondent’s concern for hazards are summarized in Appendix A of this volume.
Public Outreach Events
As mentioned, many joint planning efforts occurred between the Santa Clara County MJHMP, Safety Element, and Community Wildfire Protection Plan. This is the first time in Santa Clara County history that this kind of planning effort and coordination has occurred. There were several public meetings for each planning initiative, and each meeting included presentations about the Multijurisdictional Hazard Mitigation Plan.
By engaging the public both virtually and in person, the concept of mitigation was widely shared, and the public was provided the opportunity to review the draft plan. Participants at each meeting were encouraged to participate via the public survey. Table 6 summarizes each public outreach meeting that occurred across the OA.
Recordings of each meeting can be found at https://sccfiresafe.org/cwpp/ Figure 7: Public and Stakeholder Meeting with 99 Participants
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 4: Plan Update Approach 29
Figure 8: Public and Stakeholder Meeting with 104 Participants Table 6: Summary of Public Outreach
Date Summary of Outreach
November 10,
2022
MJHMP presentation and invitation for public comment and feedback at the joint Safety Element Virtual Town Hall (virtual)
December 6,
2022
MJHMP presentation and invitation for public comment and feedback at the joint CWPP Community Outreach Meeting Campbell (in-person)
59 fliers distributed, 24 individual risk assessments conducted, 75+ contacts made regarding the plan
December 7,
2022
MJHMP presentation and invitation for public comment and feedback at the joint CWPP Community Outreach Meeting San Jose (in-person)
December 13,
2022
MJHMP presentation and invitation for public comment and feedback at the joint CWPP Community Outreach Meeting Milpitas (in-person)
December 15,
2022
MJHMP presentation and invitation for public comment and feedback at the joint CWPP Community Outreach Meeting Morgan Hill (in-person) December 15,
2022
MJHMP presentation and invitation for public comment and feedback at the joint Safety Element CARAS South County Community Listening Meeting (in-person) March 15,
2023
MJHMP presentation and invitation for public comment and feedback at the joint Safety Element Listening Session
June 14-28, 2023 Draft MJHMP published online and a public comment period was in place for two weeks. Comments were considered and implemented where applicable.
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 4: Plan Update Approach 30
Draft MJHMP Public Comment Period
During the development of the MJHMP, the public had the opportunity to review the Draft and make final comments. Every participating jurisdiction advertised this public comment period by using multiple online resources, including official social media accounts, websites, and online newsletters. These comments were taken into consideration and implemented where applicable.
Figure 9: Samples of Public Comment Period Advertisements Public Representation
In addition to directly providing the public the opportunity to comment on the plan, the Santa Clara County Access and Functional Needs and Cultural Competency Working Group which represents tens of community and faith-based organizations within the SCC operational area were consulted on the plan and were able to provide feedback based on the populations they serve. Approximately 100 non-profits and VOAD members participate in the AFN and Cultural Competency Working Group. SCC also has representation from community centers and two consulate generals. In addition, there are also advocates who do not have an affiliation but are Santa Clara County residents and provide input on LGBTQ+ and Disability topics. Some of the organizations include but are not limited to San Andreas Regional Center, Immigrant Info Services, Vista Center for the Blind, American Red Cross, Parents Helping Parents, Lighthouse. In general, the direct interaction and represented voices shared similar sentiments in concern for specifically the extreme heat and wildfire hazard, community preparedness, and education and outreach activities. Therefore, prioritization of the wildfire hazard, and the corresponding mitigation actions, along with high attention to public outreach and education efforts informed the many such related mitigation actions in the plan.
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 4: Plan Update Approach 31
4.8 Plan Development Chronology and Milestones
Table 7 summarizes important milestones in the plan update process.
Table 7: Plan Development Chronology and Milestones
Date Event Description
December
8, 2022
Initial meeting with Core Planning
Team
Planning groups
IEM project staff
Project phases
Proposed workshop schedule
Administration and logistics
December
14, 2022
Kick off meeting with planning
partners
Introductions
IEM project staff
Planning groups
Mitigation overview
Mitigation planning benefits
Intent of plan update
Plan participants
Hazards covered
Updated FEMA requirements
Planning expectations
Project phases
County planning efforts underway
Plan integration opportunities
Stakeholder identification
Use of SharePoint
January 18,
2023
Community Capabilities Review
Workshop with planning partners
Planning groups
Planning process contacts
▪ Local planning teams
▪ Internal stakeholders
▪ External stakeholders
Capabilities assessment
National Flood Insurance Program (NFIP)
Use of SharePoint
February
15, 2023
Risk Assessment Workshop with
planning partners
Project phases
Public outreach and documentation
Hazus
GIS
Community Rating System (CRS)
Risk assessment
Planning documents
Risk ranking
March 15,
2023
Stakeholder Engagement
Workshop #1
Workshop goals
Hazard mitigation planning
▪ Overview
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 4: Plan Update Approach 32
Date Event Description
▪ Planning process
Project phases
Mitigation action items
Feedback on data sources
April 3,
2023
Stakeholder Engagement
Workshop #2
Workshop goals
Multijurisdictional hazard mitigation plan recap
Mitigation strategy
Mitigation action items
Funding sources
Mitigation integration
April 3,
2023
Mitigation Strategy Workshop with
planning partners
Mitigation strategy
Mitigation projects working group
2017 mitigation strategy
Review of 2017 actions
New action items
Mitigation incorporation
April 4,
2023
Public survey published on County
of Santa Clara Office of
Emergency Management website
Thirty-five question survey published at
https://emergencymanagement.sccgov.org/pa
rtners/hazard-mitigation-program
April 18,
2023
Mitigation Strategy Working Group
Meeting
Working group expectations
Review of 2017 MHMP goals and objectives
Review of 2017 MHMP projects
Discussion of the current gaps in identifying
projects and accessing funding
May 19,
2023
Public survey closed Total of 588 responses received: 576 in English, 10 in Chinese, and 2 in Spanish.
June 2,
2023
Planning process wrap up meeting
with planning partners
Public survey results summary
Implementation
Monitoring and evaluation
Maintenance
Adoption
Draft review
Draft plan publicity for public and stakeholders
July 13,
2023
Draft plan published on County of
Santa Clara Office of Emergency
Management website for public
and stakeholder review
Public comment period was open for two weeks
to give the public a chance to review the Draft
and make comments.
September
25, 2023
Plan submittal to Cal OES Final draft plan submitted to Cal OES for review and approval.
January 16,
2024
Plan submittal to FEMA Final draft plan submitted to FEMA for review and approval.
Plan Approvable Pending
Adoption (APA) by FEMA.
FEMA to provide APA Letter once they approve
the final draft plan.
February 8,
2024
First planning partner adopts
approved plan.
All participants must formally adopt the plan. The
five-year lifecycle begins with the first adoption.
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 33 5 Santa Clara County Operational Area Profile
5.1 Geographic Overview
The Santa Clara County Operational Area is in north-central California in the southern portion of the San Francisco Bay area (see Figure 9). With its numerous natural amenities and one of the highest standards of living in the country, the OA has long been considered one of the best areas in the United States in which to live and work. The county is also referred to as “Silicon Valley.” The Santa Clara County OA has a total area of 1,312 square miles. With a diverse population of more than 1.9 million residents,6F6F
7 it is one of the largest counties in the state and encompasses 15 incorporated cities.
San José is the largest city, with just over 1 million people,7F7F 8 followed by Sunnyvale and Santa Clara; the
west valley bedroom communities of Los Altos, Los Altos Hills, Los Gatos, Monte Sereno, and Saratoga; the high-tech communities of Campbell, Cupertino, Mountain View, and Palo Alto; industrial Milpitas, and the south county suburban expansion/rural interface areas of Gilroy, Morgan Hill, and their surrounding unincorporated areas. A significant portion of the county’s land area is unincorporated ranch and farmland.
The OA has a rich culture of ethnic diversity, artistic endeavors, sports venues, and academic institutions.
Numerous public and private golf courses are located throughout the OA and Santa Clara County operates 28 parks covering more than 50,000 acres, including lakes, streams, and miles of hiking and biking trails. The OA is home to three major universities—Stanford University, Santa Clara University, and San José State University—as well as several community colleges.
5.2 Historical Overview
The early inhabitants of the area now known as Santa Clara County were the indigenous Ohlone people, thought to occupy the area at least 1,000 years before Spain began to colonize California in the 18th century.
Spanish settlers established the Santa Clara Valley’s first mission and pueblo in Santa Clara and San José, respectively, and governed “El Llano de Los Robles” (Plain of the Oaks), until the Mexican Revolution led to Mexican control from the 1820s through 1840s. In 1850, California was admitted into the United States, and Santa Clara County was incorporated as one of the state’s original 27 counties.
Deriving its name from Mission Santa Clara, the county originally included much of what was Washington Township (part of Union City and Fremont) in what is now Alameda County. The current county boundaries were set in 1853 when Alameda County was established.
From 1850 to 1870, ranchers made a transition from raising cattle and sheep to cultivating hay and grain.
French immigrants planted the first vineyards. Mercury mining flourished. California’s first colleges were founded in Santa Clara County and the coming of the railroad produced a small boom in real estate. 7 United States Census Bureau. (2020). Quick Facts: Santa Clara County. https://www.census.gov/quickfacts/santaclaracountycalifornia 8 United States Census Bureau. (2020). Quick Facts: San José City. https://www.census.gov/quickfacts/fact/table/sanjosecitycalifornia,santaclaracountycalifornia/PST045222
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 34 Figure 10: Santa Clara County Operational Area (Planning Area) After 1870, orchards began displacing grain fields and vineyards. The Santa Clara Valley became the world’s leading producer of canned fruit and processed dried fruit. By the end of the 19th century, wealthy San Franciscans, such as Leland Stanford and James Lick, established farms and summer homes in the county.
Santa Clara County remained pastoral until World War II, when many people gravitated to California to work in war-related industries. To accommodate the growing population, mass-produced housing spread across the Santa Clara Valley, and agricultural land was subdivided and developed for housing. Like much of the rest of the United States in the decades immediately following the war, development in the county shifted from largely agricultural to largely suburban.
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 35 At the same time, technology companies began to flourish in Santa Clara County, with significant support and encouragement from Stanford University. The Stanford Industrial Park, established in 1951, later became the Stanford Research Park and provided space for companies such as Hewlett-Packard, Eastman Kodak, General Electric, and Lockheed. Related companies began to form around the region, and by the 1970s Santa Clara County and surrounding areas became known as a center of hightechnology development. The term Silicon Valley was coined in 1971, referring to the high concentration of companies in the area that are involved in making silicon semiconductors and the computers that rely on them. Technology industries remain central to the area’s economy to this day.
5.3 Major Past Hazard Events
Presidential disaster declarations are typically issued for hazard events that cause more damage than state and local governments can handle without assistance from the federal government. A presidential disaster declaration puts federal recovery programs into motion to help disaster victims, businesses, and public entities. Some of the programs are matched by state programs. Santa Clara County has experienced 20 events (14 major disaster declarations, three emergency declarations, two fire management assistance declarations, and one fire suppression declaration) since 1950 for which presidential disaster declarations were issued. These events are listed in Table 8.
Table 8: Presidential Disaster Declarations8F8F
9 Type of Event FEMA Disaster
Number* Date
Severe Winter Storm DR-3592 03/10/2023
Severe Winter Storms, Flooding, Landslides, and Mudslides DR-4683 January 14, 2023 Severe Winter Storms, Flooding, and Mudslides EM-3591 January 9, 2023 Wildfires DR-4558 August 22, 2020
SCU Lightning Complex Fire DR-5338 August 21, 2020
COVID-19 Pandemic DR-4482 March 22, 2020
COVID-19 EM-3428 March 13, 2020
Severe Winter Storms, Flooding, and Mudslides DR-4308 April 1, 2017 Severe Winter Storms, Flooding, and Mudslides DR-4301 February 14, 2017 Summit Fire DR-2766 May 22, 2008
Wildfires DR-3287 06/28/2008
Croy Fire FS-2465 September 25, 2002
Severe Winter Storms and Flooding DR-1203 February 9, 1998 Severe Storms, Flooding, Mudslides, and Landslides DR-1155 January 4, 1997 Severe Winter Storms, Flooding Landslides, and Mud Flow DR-1046 March 12, 1995 Severe Winter Storms, Flooding, Landslides, and Mud Flows DR-1044 January 10, 1995 Severe Freeze DR-894 February 11, 1991
Loma Prieta Earthquake DR-845 October 18, 1989
Severe Storms and Flooding DR-758 February 21, 1986
Grass, Wildlands, and Forest Fires DR-739 July 18, 1985 9 Federal Emergency Management Agency. (2023). Declared Disasters. https://www.fema.gov/disaster/declarations
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 36 Type of Event FEMA Disaster
Number* Date
Coastal Storms, Floods, Slides, and Tornadoes DR-677 February 9, 1983 Severe Storms, Flood, Mudslides, and High Tide DR-651 January 7, 1982 Drought EM-3023 January 20, 1977
* DR = Disaster Declaration; EM = Emergency Declaration; FM = Fire Management; FS = Fire Suppression Review of these events helps to identify targets for risk reduction and ways to increase a community’s capability to avoid large-scale events in the future. Still, many natural hazard events do not trigger federal disaster protocol but have significant impacts on their communities. These events are also important to consider in establishing recurrence intervals for hazards of concern. Additional information about previous hazard events is included in Section 6 of this plan.
5.4 Physical Setting
5.4.1 Geology and Topography
The OA’s topography is characterized by its location in the southern San Francisco Bay area. The Santa Clara Valley runs the entire length of the county from north to south, ringed by the rolling hills of the Diablo Range on the east, and the Santa Cruz Mountains on the west. Salt marshes and wetlands lie in the northwestern part of the county, adjacent to the waters of San Francisco Bay.
5.4.2 Soils
Prior to 1950 and as far back as the late 1800s, Santa Clara Valley was the scene of a vibrant and productive agriculture industry. Many of the soils of the Santa Clara Valley are alluvial, deposited on fans or floodplains within the valley. The young, deep soils (Elder, Elpaloalto, Still, Stevens Creek, Landelspark, Botella, and Campbell) are naturally very fertile. Field crops were cultivated on the lower parts of the valley, and orchards spanned from the hills east of Milpitas and San José across the valley to Los Altos and Palo Alto. With the introduction of the electric water pump in the early 20th century, irrigation water from the plentiful ground-water supply became readily available on farms, increasing productivity.
The Santa Clara Valley became widely known for the production of high-quality orchard fruits, which were shipped across the United States.
Dams were constructed on major streams to store irrigation water and control flooding. As groundwater was rapidly pumped from a depth of several hundred feet, subsurface materials compacted which led to land subsidence. Subsidence damaged pipes and other in-ground structures, and levees were required to block tidewater from entering subsided land. The benefit of this control of streams and pumping of groundwater was a valley relatively free from flooding and high groundwater, an ideal condition for the rapid urban expansion that followed.
After World War II, urban growth in the San Francisco Bay area began to expand down to the south end of the bay and into the Santa Clara Valley. After 1950, the pace of development quickened, and subdivisions began to spring up. The first wave of development occurred on the soils along the El Camino Real corridor, where the alluvial fans were relatively level, with slopes of 2 percent or less. Development exploded in the 1960s and topsoil was moved to house lots from the street areas. This type of subdivision construction continued until about 1980, when more shaping of house lots to control drainage began. By 1980, home construction had started to slow because many of the level areas fit for construction were now already developed.
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 37 After 1980, subdivision development moved up areas of alluvial fans and greater slopes, and lot-shaping became more common. After 1990, development moved into steep areas at the edge of the valley and the foothills. Soil disturbance can be severe in these areas, with more than 5 feet of cuts or fills.
Fills may consist of materials from several feet below the soil surface, have a high content of clay or fragments, and be low in organic matter and fertility. Cut areas may have subsoil materials at the surface, which also may have a high content of clay or fragments and be low in organic matter and fertility. Many residents have modified the soil surface texture in garden areas with sandy materials and mulches. In areas of the basin soils (Hangerone, Clear Lake, and Embarcadero), clay surface and subsurface textures and slow internal drainage due to a high clay content are problems for gardens, ornamental plants, and lawns.9F9F
10 5.4.3 Climate
Table 9 summarizes normal climate date from 1981 through 2022 at the National Climatic Data Center weather station at San José. The Mediterranean climate of the OA remains temperate year-round due to the area’s geography and its proximity to the Pacific Ocean. The area is warm and dry much of the year.
Rarely is the humidity uncomfortable, and the thermometer seldom drops below freezing. Rain is generally limited to winter and snow to the tops of local mountains.
Table 9: Normal Precipitation and Temperatures in the Operational Area, 1981–202210F10 F 11 Months Mean Precipitation
(inches)
Minimum
Temperature (°F)
Maximum
Temperature (°F)
January 2.65 32 68
February 2.56 35 74
March 2.28 38 79
April 0.91 41 87
May 0.41 46 91
June 0.10 50 97
July 0.01 53 95
August 0.02 54 96
September 0.16 51 95
October 0.66 45 90
November 1.55 37 77
December 2.35 32 68
Annual 13.39 30 100
10 United States Department of Agriculture. (2015). Supplement to the Soil Survey of Santa Clara. https://www.nrcs.usda.gov/conservation-basics/natural-resource-concerns/soil/soil-science 11 National Oceanic and Atmospheric Administration. (n.d.). Climate Data Online. https://www.ncei.noaa.gov/cdo-web/
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 38
5.5 Development Profile
5.5.1 Land Use
Table 10 shows current land use for unincorporated Santa Clara County; complete land use data was not available for municipalities in the OA. Land use information is analyzed in this plan for each identified hazard that has a defined spatial extent and location.
For hazards that lack this spatial reference, the information in the table serves as a baseline estimate of land use and exposure. The distribution of land uses for the unincorporated county will change over time.
Table 10: Unincorporated County Land Use
Type of Land Use Area (acres) Percentage of Total Area
Agricultural 33,355.5 5.53
General / Institutional 5,381.3 0.89
Open Space 548,603.4 90.88
Low Density Residential 15,988.7 2.65
High Density Residential 68.6 0.01
Commercial 161.8 0.03
Industrial 85.0 0.01
Total 603,644.5 100.00
5.5.2 Critical Facilities, Infrastructure, and Assets
Critical facilities and infrastructure are those that are essential to the health and welfare of the population.
These features become especially important after a hazard event. Critical facilities typically include public safety stations, schools, department operation centers, and emergency operations centers. Critical infrastructure can include the roads and bridges that provide ingress and egress and allow emergency vehicles access to those in need, and the utilities that provide water, electricity, and communication services to the community. Critical facilities identified in this plan were selected, mapped, and included in geographic information system (GIS) databases based on information provided through the Working Group meetings, stakeholder information requests, and the 2018 State of California Multi-Hazard Mitigation Plan.
Although many facilities and assets of the Santa Clara County OA are important to the quality of life, this plan focuses on those whose loss would result in the greatest impacts on life and safety in the event of a natural hazard. As defined for this hazard mitigation plan update, critical facilities are:
Structures or other improvements, public or private, that, because of function, size, service area, or uniqueness, have the potential to cause serious bodily harm, extensive property damage, or disruption of vital socioeconomic activities if it is destroyed or damaged or if its functionality is impaired. Critical facilities may include but are not limited to health and
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 39 safety facilities, utilities, government facilities, hazardous materials facilities, or vital community economic facilities.1F1F 12 All critical facilities and infrastructure were analyzed in Hazus to help rank risk and identify mitigation actions. The risk assessment for each hazard qualitatively discusses critical facilities with regard to that hazard. Table 11 summarizes the general types of critical facilities and infrastructure by local jurisdiction.
Figure 10 and Figure 11 show the locations of critical facilities and infrastructure in the OA. Due to the sensitivity of this information, a detailed list of facilities is not provided. The list is on file with Santa Clara County OEM.
Table 11: Critical Facilities and Infrastructure in the Operational Area Jurisdiction Essential
Facilities Transportation Utilities Hazardous Materials Community
Assets Jurisdiction
Campbell 21 23 0 6 7 93
Cupertino 26 26 2 5 16 95
Gilroy 25 34 2 7 13 118
Los Altos 22 8 0 0 11 73
Los Altos Hills 6 21 0 0 2 55
Los Gatos 20 35 0 1 6 79
Milpitas 32 66 1 60 19 178
Monte Sereno 1 1 0 0 1 5
Morgan Hill 22 14 1 8 10 69
Mountain View 37 52 1 20 29 174
Palo Alto 49 42 4 26 46 207
San José 370 498 18 135 191 1,479
Santa Clara
(city)
53 63 9 103 36 295
Saratoga 18 32 0 0 11 70
Sunnyvale 40 49 3 51 27 232
Unincorporated
County
38 187 17 4 48 327
Total 777 1151 58 426 473 3,549
12 Organization of American States. (n.d.). Critical Facilities Mapping. https://www.oas.org/dsd/publications/Unit/oea66e/ch07.htm
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 40 Figure 11: Critical Facilities in the Operational Area
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 41 Figure 12: Critical Infrastructure in the Operational Area
5.5.3 Future Trends in Development
An understanding of population and development trends can assist in planning for future development and ensuring that appropriate mitigation, planning, and preparedness measures are in place to protect human health and community infrastructure. The DMA requires that communities consider land use trends, which can alter the need for, and priority of, mitigation options over time. Land use and development trends significantly affect exposure and vulnerability to various hazards. For example, significant development in a hazard area increases the building stock and population exposed to that hazard. New development that has occurred in the last five years within the OA and potential future development in the next five years, as identified by each jurisdiction, is addressed in the planning partner annexes located in Volume 2 of this plan.
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 42 The municipal planning partners have adopted general plans that govern land use decision and policy making for their jurisdictions. Decisions on land use will be governed by these programs. This plan will work together with these programs to support wise land use in the future by providing vital information on the risk associated with natural hazards in the OA. Incorporating information from the hazard mitigation into the general plan as the plans are updated will ensure that future development will be established with the benefits of the information on risk and vulnerability to natural hazards identified in this plan.
5.6 Demographics
Some populations are at greater risk from hazard events because of decreased resources or physical abilities. Those who are older, for example, may be more likely to require additional assistance. Research has shown that people living near or below the poverty line, those who are older, women, children, those who are racial and/or ethnic minorities, renters, individuals with disabilities, and others with access and functional needs, may all experience more severe impacts from disasters than the general population.
These more vulnerable populations may vary from the general population in risk perception, living conditions, access to information before, during, and after a hazard event, capabilities during an event, and access to resources for post-disaster recovery. Indicators of vulnerability—such as disability, age, poverty, and minority race and ethnicity—often overlap spatially and often in the geographically most vulnerable locations. Detailed spatial analysis to locate areas where there are higher concentrations of more vulnerable community members helps to extend focused public outreach and education and resources to these most vulnerable residents.
5.6.1 Population
Resident Population
Information about population is a critical part of planning because it directly relates to land needs such as housing, industry, stores, public facilities and services, and transportation. The 2020 U.S. Census estimated the OA’s population at 1,936,259.12 F12F
13 Population changes are useful socio-economic indicators. A growing population generally indicates a growing economy, while a decreasing population signifies economic decline. In this case, population estimates are assumed to be influenced by the COVID-19 pandemic, rising cost of living including housing, and decline in foreign immigration due to change in federal policy. Since 2011, California has experienced an increased number of people moving out of the State in a year than into it. The OA is no exception. Table 12 shows the population in the OA from 2000 to 2022 according to the California Finance Department.
Table 12: Recent Population Data13F13F
14 Jurisdiction
Population
2000 2005 2010 2015 2022
City of Campbell 38,138 37,406 39,349 41,986 42,833
13 United States Census Bureau. (2020). Quick Facts: Santa Clara County. https://www.census.gov/quickfacts/santaclaracountycalifornia 14 State of California Department of Finance. (2021, December). E-2 California County Population Estimates and Components of Change by Year. https://dof.ca.gov/Forecasting/Demographics/e-2-california-county-populationestimates-and-components-of-change-byyear/#:~:text=California%E2%80%99s%20population%20declined%20by%20173%2C000%20persons%20between %20July,estimates%20released%20today%20by%20the%20Department%20of%20Finance.
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 43 Jurisdiction
Population
2000 2005 2010 2015 2022
City of Cupertino 50,546 53,632 58,302 58,038 59,610
City of Gilroy 41,464 45,782 48,821 54,324 59,269
City of Los Altos 27,693 27,381 28,976 30,513 31,526
Town of Los Altos Hills 7,902 7,852 7,922 8,595 8,400
Town of Los Gatos 28,592 28,070 29,413 31,157 33,062
City of Milpitas 62,698 62,177 66,790 74,140 80,839
City of Monte Sereno 3,483 3,324 3,341 3,445 3,488
City of Morgan Hill 33,556 35,011 37,822 42,382 46,451
City of Mountain View 70,708 70,629 74,066 76,712 83,864 City of Palo Alto 58,598 60,723 64,403 67,331 67,473
City of San José 894,943 901,159 945,942 1,030,053 976,482 City of Santa Clara 102,361 107,058 116,468 121,580 130,127 City of Saratoga 29,843 29,630 29,926 30,060 30,667
City of Sunnyvale 131,760 131,853 140,081 146,629 156,234 Unincorporated County 100,300 96,547 90,020 87,029 84,458 Total 1,682,585 1,698,234 1,781,642 1,903,974 1,894,783 Daily Commuting Population
According to the California Employment Development Department, Santa Clara County is the single largest commuter destination in Submarket C of the San Francisco Bay Area Economic Market, holding and/or importing 1,009,391 commuters daily.14F14F
15 This large commuter contingent has impacts on planning for the OA’s infrastructure and service needs, as well as on planning for hazard mitigation and emergency management. Commuters may be familiar with the area immediately surrounding their place of business or regular route to work but may be less familiar with the services and resources provided to the population during a disaster event.
The U.S. Census estimates that over 66.8 percent of workers in the OA commute alone (by car, truck, or van) to work, and mean travel time to work is 24 minutes. The state average is 28 minutes.15F15 F 16 5.6.2 Age Distribution
As a group, the adults who are older are more apt to lack the physical and economic resources necessary for response and resiliency for hazard events and are more likely to suffer health-related consequences making recovery slower. They are more likely to be vision, hearing, and/or mobility impaired, and more likely to experience mental impairment or dementia. Additionally, adults who are older are more likely to live in assisted- living facilities where emergency preparedness occurs at the discretion of facility operators. These facilities are typically identified as “critical facilities” by emergency managers because 15 California Employment Development Department. (2020, August 28). WIOA Regional Planning Units. https://edd.ca.gov/siteassets/files/Jobs_and_Training/pubs/wsd20-01.pdf 16 United States Census Bureau. (2020). Quick Facts: Santa Clara County; California. https://www.census.gov/quickfacts/fact/table/santaclaracountycalifornia,CA/LFE305221
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 44 they require extra notice to implement evacuation. Residents who are older and living in their own homes may have more difficulty evacuating and could be stranded in dangerous situations. This population group is more likely to need special medical attention, which may not be readily available during natural disasters due to isolation caused by the event. Specific planning attention for the those who are older is an important consideration given the current trend of aging of the American population.
Children under 18 are particularly vulnerable to disaster events as well because of their young age and dependence on others for basic necessities. Children often experience increased physical and health challenges as well as issues learning after a disaster event. Additionally, very young children may be vulnerable to injury or sickness; this added vulnerability can be worsened during a natural disaster because they may not understand the measures that need to be taken to protect themselves from hazards. The unique needs of children are important to factor into disaster response and recovery efforts as well as when calculating the benefit and costs of mitigation alternatives. 16F16 F 17 The overall age distribution for the OA is illustrated in Figure 13. Based on U.S. Census 2021 American Community Survey 1-Year Estimate, the mean age in the OA is 48.2 compared to California’s mean age of 37.6 years. Additionally, 14.5 percent of the OA’s population is 65 or older, compared to the state estimate of 15.2 percent. An estimated 21.2 percent of the OA population is 18 or younger, compared to the state estimate of 22.4 percent.
Figure 13: Overall Age Distribution in the Operational Area17F17F 18 17 Society for Research in Child Development. (2020, August 13). Understanding the Impacts of Natural Disasters on Children. https://www.srcd.org/research/understanding-impacts-natural-disasterschildren#:~:text=Every%20year%2C%20175%20million%20children%20globally%20are%20expected,communities% 20better%20prepare%20for%20and%20respond%20to%20disasters. 18 United States Census Bureau. (2021). American Community Survey, Age and Sex Santa Clara County, California. https://data.census.gov/table?q=Age+in+Santa+Clara+County+2021&tid=ACSST1Y2021.S0101
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 45
5.6.3 Race, Ethnicity, and Language
Research shows that racial and ethnic minorities are less likely to be involved in pre-disaster planning and experience higher mortality rates during a disaster event. Post-disaster recovery can be ineffective and is often characterized by cultural insensitivity. Since higher proportions of ethnic minorities live below the poverty line than the majority white population, poverty can compound vulnerability. According to the 2020 U.S. Census, the racial composition of the OA is predominantly Asian, at about 39 percent. The next most common race is White, at 32 percent. The racial distribution in the OA is shown below.
The OA has a 40.3 percent foreign-born population. Other than English, the most commonly spoken languages in the OA are Chinese, Vietnamese, and Tagalog, followed by Spanish.18F18F 19 Figure 14: Race Distribution in the Operational Area19F19F 20 5.6.4 Education
Understanding educational attainment of the population is important when developing appropriate outreach and educational materials. The U.S. Census estimates that 28 percent of the population OA 25 years and older has attained a bachelor’s degree, and 27 percent a graduate or professional degree.
Seventy-six percent of the population has attended college for some period, and 10 percent have not achieved a high school or equivalent degree.20 F20F
21 19 United States Census Bureau. (2020). Santa Clara County, California. https://data.census.gov/profile?g=050XX00US06085
20 United States Census Bureau. (2020). Santa Clara County, California. https://data.census.gov/profile?g=050XX00US06085
21 United States Census Bureau. (2020). Santa Clara County, California. https://data.census.gov/profile?g=050XX00US06085
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 46
5.6.5 Individuals with Disabilities or with Access or Functional Needs The U.S. Census estimates that over 42 million non-institutionalized people with disabilities live in the U.S. Individuals with disabilities are more likely to have difficulty with resilience and responding to a hazard event than the general population.21F21F
22 Local government may be the first level of response to assist these individuals, and coordination of efforts to meet their access and functional needs is paramount to life safety efforts. It is important for emergency and incident managers to distinguish between functional and medical needs in order to plan for incidents that require evacuation and sheltering. Knowing the percentage of population with a disability will allow emergency management personnel and first responders to have personnel available who can provide services needed by those with access and functional needs.
According to the U.S. Census 2021 American Community Survey 1-Year Estimates, 169,467, or 9 percent, of individuals have some form of disability in the OA.2 F2F 23 5.6.6. Social Vulnerability
The Social Vulnerability Index provides a visual representation of the potential negative effects on communities that natural hazards or other external stresses on human health. The index is based on 16 variables from the U.S. Census to indicate areas that may need additional support before, during or after disasters. These indices include measures of socioeconomic status, household characteristics, racial and ethnic minority status, and housing type and transportation. The overall social vulnerability for Santa Clara County is shown in Figure 14. A summary of the four categories of indices that contribute to the overall index is shown in Figure 15. The darker toned colors indicate areas with potentially higher vulnerability.
22 United States Census Bureau. (2020). United States. https://data.census.gov/profile/United_States?g=010XX00US 23 United States Census Bureau. (2020). Santa Clara County, California. https://data.census.gov/profile?g=050XX00US06085
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 47 Figure 15: Santa Clara County Social Vulnerability Index
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 48 Figure 16: Social Vulnerability Index Themes
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 49
5.7 Economy
5.7.1 Income
In the United States, individual households are expected to use private resources to prepare for, respond to and recover from disasters to some extent. This means economically disadvantaged households are automatically disadvantaged when confronting hazards. Additionally, those who are economically disadvantaged typically occupy more poorly built and inadequately maintained housing. Mobile or modular homes, for example, are more susceptible to damage in earthquakes and floods than other types of housing. In urban areas, those who are economically disadvantaged often live in older houses and apartment complexes, which are more likely to be made of un-reinforced masonry, a building type that is particularly susceptible to damage during earthquakes. Furthermore, those who are economically disadvantaged are less likely to have insurance to compensate for losses incurred from natural disasters.
This means they may have a great deal to lose during an event and may be the least prepared to deal with potential losses. The events following Hurricane Katrina in 2005 illustrated that personal household economics significantly impact people’s decisions on evacuation. Individuals who cannot afford gas for their cars will likely decide not to evacuate.
A living wage calculator developed at the Massachusetts Institute of Technology estimates the hourly living wage needed to support different types of families. The calculator takes into consideration basic needs such as health, housing, transportation, and other necessities and interprets the living wage as a geographically specific hourly rate required to acquire basic minimum necessities cost. Table 13 presents summary information from the living wage calculator for 2022. Each hourly rate is adjusted per each working adult.
Table 13: Hourly Living Wage Calculation for Santa Clara County, California (2022)23F23 F 24 Wage Level One Adult One Adult + Two
Children Two Adults Two Adults + One Child
Living Wage $26.86 $68.69 $38.42 $46.79
Poverty Wage $6.53 $11.07 $8.80 $11.07
Minimum Wage $15.50 $15.50 $15.50 $15.50
Based on 2022 U.S. Census Bureau estimates, the median household income in Santa Clara County was $141,562. It is estimated that about 16 percent of households receive an income between $100,000 and $149,999 per year and over 47 percent of household incomes are above $150,000 annually. About 9 percent of the households in the OA make less than $25,000 per year. The poverty threshold for a family of four in 2022 was $30,186; for a family of three, $22,892; for a family of two under 65 years, $19,597 and for unrelated individuals under 65 years, $15,225.24 F24F 25 The 2015 living wage calculations cited in the 2017 Hazard Mitigation Plan were notably different than the current estimates. For example, the living wage for one adult was $14.52 and $11.30 for two adults.
When incomes do not match the cost-of-living increase, households may be forced to reduce household on nonessential items. Hazard mitigation measures, such as flood insurance and voluntary structural retrofitting, are not usually considered essential despite their demonstrated long-term cost effectiveness. 24 Massachusetts Institute of Technology. (2023). Living Wage Calculator, Santa Clara County. https://livingwage.mit.edu/counties/06085
25 United States Census Bureau. (2020). Santa Clara County, California. https://data.census.gov/profile?g=050XX00US06085
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 50
5.8 Industry, Businesses, and Institutions
The county’s economy is strongly based in the professional, scientific, and management, and administrative and waste management services industry, followed by educational services and health care and social assistance, manufacturing, and retail trade. Figure 16 shows the breakdown of industry types in the OA. Santa Clara County is part of one of the state’s busiest urbans areas.
The OA benefits from a variety of business activity. Major businesses include Apple, Inc, Alphabet Inc. (Google), Netflix, Roku, Inc. Shockley Semiconductor Laboratory, eBay Inc., Cisco Systems Inc., Applied Materials Inc., Flextronics International, Intel Corp, Kaiser Permanente Medical Center, Liberty Tax Service, Lockheed Martin Space Systems, NASA, Phillips Lumileds Lighting Company, Santa Clara Valley Medical Center, and many others.
Major educational and research institutions in the OA include Stanford University, San José State University, Santa Clara University, Mission College, De Anza College, Foothill College, West Valley College, Mission College, Evergreen Valley College, San José City College, and Gavilan College.
Figure 17: Industry in Santa Clara County
5.8.1 Employment Trends and Occupations
According to the Census Bureau, 66.6 percent of the Santa Clara County population 16 years and over is in the labor force. Management, business, science, and arts occupations make up 59 percent of jobs in the County. Other major occupations include sales and office (15 percent) and service (13 percent).
Multiple major employers in California are located in Santa Clara County, including Apple, Cisco Systems, Advanced Micro Devices Inc, Amazon, Apple, Applied Materials Inc, California’s Great America, Cisco
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 51 Systems, Intel Corp, Intuit, Hewlett Packard Enterprise, Alphabet Inc. (Google), and Nvidia Corp., and Yahoo. The largest of these are Applied Materials Inc, Apple, Cisco Systems, Intel Inc, Hewlett Packard Enterprise, Google, and Yahoo each with 10,000 or more employees. The others employ between 1,000- 4,999 employees.25F25F
26 Figure 18: Occupations in Santa Clara County
The figure below compares the California and the Santa Clara County unemployment trends from 2017 to 2021. According to the State of California’s Employment Development Department, the Santa Clara County unemployment rate was trending downward prior to 2020 when it spiked upward, likely in part due to the COVID-19 pandemic. By 2021, the unemployment rates started to fall again. They continued to fall below pre-pandemic estimates in 2022. Overall, Santa Clara County experienced less unemployment than the rest of the State throughout this time period.26 F26F 27 26 United States Census Bureau. (2021). American Community Survey, Selected Economic Characteristics Santa Clara County, California.
https://data.census.gov/table?q=employment+in+Santa+Clara+County,+California&tid=ACSDP1Y2021.DP03 27 State of California Employment Development Department. (2023). Economic Development Data Library. https://data.edd.ca.gov/
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 52 Figure 19: California and Santa Clara County Unemployment Rate27F27 F 28 5.9 Laws and Ordinances
Existing laws, ordinances, and plans at the federal, state, and local level can support or impact hazard mitigation actions identified in this plan. Hazard mitigation plans are required to include a review and incorporation, if appropriate, of existing plans, studies, reports, and technical information as part of the planning process (44 CFR, Section 201.6(b)(3)). The following federal and state programs have been identified as programs that may interface with the actions identified in this plan. Each program enhances capabilities to implement mitigation actions or has a nexus with a mitigation action in this plan.
Information presented in this section can be used in addition to local capabilities to implement the actions found in the jurisdictional and special district annexes of Volume 2 of this plan. Each planning partner has individually reviewed existing local plans, studies, reports, and technical information in its jurisdictional or special district annexes, presented in Volume 2 of this plan.
5.9.1 Federal
Stafford Act
The Stafford Disaster Relief and Emergency Assistance Act (“Stafford Act”) is the statutory authority for most Federal disaster response activities for FEMA and FEMA programs. The Stafford Act initially provided limited resources mitigation and pre-disaster community resilience. It did include the PresDisaster Hazard Mitigation (PDM) program however, funding was often ad hoc and historically much less than traditional disaster spending. Subsequent legislation has since amended the Stafford Act, opening the doors to additional mitigation opportunity.
28 State of California Employment Development Department. (2023). Economic Development Data Library. https://data.edd.ca.gov/
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 53 Disaster Mitigation Act
The DMA is the current federal legislation addressing hazard mitigation planning. It emphasizes planning for disasters before they occur. It specifically addresses planning at the local level, requiring plans to be in place before certain hazard mitigation funds are available to communities. This plan is designed to meet the requirements of DMA, improving eligibility for future hazard mitigation funds.
Disaster Recovery Reform Act
The Disaster Recovery Reform Act of 2018 amended the Stafford Act and provided 56 provisions for FEMA policy or regulation changes. Crucially, the Act set aside 6 percent of the total aid amount awarded in the previous year for pre-disaster mitigation. FEMA estimates this mean $300-500 million dollars will be available for mitigation annually.28F28F
29 This creates a much more consistent, reliable stream of pre-disaster mitigation dollars than ever seen before. Additionally, the Act expanded language for the Hazard Mitigation Grant Program (HMGP) to include an increased focused on resilience and reducing future damage in the post-disaster environment which may encourage proactive mitigation measures. It also provided states, tribes, and local jurisdictions with additional authority to use FEMA funding to rebuild to the latest building codes to reduce future risk to the Nation.
National Environmental Policy Act
The National Environmental Policy Act (NEPA) requires federal agencies to consider the environmental impacts of proposal actions and reasonable alternatives to those actions, alongside technical and economic considerations. NEPA established the Council on Environmental Quality (CEQ), whose regulations (40 CFR Parts 1500-1508) set standards for NEPA compliance. Consideration and decisionmaking regarding environmental impacts must be documented in an environmental impact statement or environmental assessment. Environmental impact assessment requires the evaluation of reasonable alternatives to a proposed action, solicitation of input from organizations and individuals that could be affected, and an unbiased presentation of direct, indirect, and cumulative environmental impacts. FEMA hazard mitigation project grant applications require full compliance with applicable federal acts. Any action identified in this plan that falls within the scope of this act will need to meet its requirements.
Endangered Species Act
The federal Endangered Species Act (ESA) was enacted in 1973 to conserve species facing depletion or extinction and the ecosystems that support them. The act sets forth a process for determining which species are threatened and endangered and requires the conservation of the critical habitat in which those species live. The ESA provides broad protection for species of fish, wildlife and plants that are listed as threatened or endangered. Provisions are made for listing species, as well as for recovery plans and the designation of critical habitat for listed species. The ESA outlines procedures for federal agencies to follow when taking actions that may jeopardize listed species and contains exceptions and exemptions.
It is the enabling legislation for the Convention on International Trade in Endangered Species of Wild Fauna and Flora. Criminal and civil penalties are provided for violations of the ESA and the Convention. 29 Federal Emergency Management Agency (FEMA). (2020). Hazard Mitigation Assistance. https://sgp.fas.org/crs/homesec/IN11187.pdf
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 54 Federal agencies must seek to conserve endangered and threatened species and use their authorities in furtherance of the ESA’s purposes. The ESA defines three fundamental terms:29F29F 30 Endangered means that a species of fish, animal or plant is “in danger of extinction throughout all or a significant portion of its range.” (For salmon and other vertebrate species, this may include subspecies and distinct population segments.)
Threatened means that a species “is likely to become endangered within the foreseeable future.” Regulations may be less restrictive for threatened species than for endangered species. Critical habitat means “specific geographical areas that are…essential for the conservation and management of a listed species, whether occupied by the species or not.” Five sections of the ESA are of critical importance to understanding it:
Section 4: Listing of a Species—The National Oceanic and Atmospheric Administration (NOAA) Fisheries Service is responsible for listing marine species; the U.S. Fish and Wildlife Service is responsible for listing terrestrial and freshwater aquatic species. The agencies may initiate reviews for listings, or citizens may petition for them. A listing must be made “solely on the basis of the best scientific and commercial data available.” After a listing has been proposed, agencies receive comment and conduct further scientific reviews for 12 to 18 months, after which they must decide if the listing is warranted. Economic impacts cannot be considered in this decision, but it may include an evaluation of the adequacy of local and state protections. Critical habitat for the species may be designated at the time of listing.
Section 7: Consultation—Federal agencies must ensure that any action they authorize, fund, or carry out is not likely to jeopardize the continued existence of a listed or proposed species or adversely modify its critical habitat. This includes private and public actions that require a federal permit. Once a final listing is made, non-federal actions are subject to the same review, termed a “consultation.” If the listing agency finds that an action will “take” a species, it must propose mitigations or “reasonable and prudent” alternatives to the action; if the proponent rejects these, the action cannot proceed.
Section 9: Prohibition of Take—It is unlawful to “take” an endangered species, including killing or injuring it or modifying its habitat in a way that interferes with essential behavioral patterns, including breeding, feeding, or sheltering.
Section 10: Permitted Take—Through voluntary agreements with the federal government that provide protections to an endangered species, a non-federal applicant may commit a take that would otherwise be prohibited as long as it is incidental to an otherwise lawful activity (such as developing land or building a road). These agreements often take the form of a “Habitat Conservation Plan.”
Section 11: Citizen Lawsuits—Civil actions initiated by any citizen can require the listing agency to enforce the ESA’s prohibition of taking or to meet the requirements of the consultation process.
FEMA hazard mitigation project grant applications require full compliance with applicable federal acts.
Any action identified in this plan that falls within the scope of this act will need to meet its requirements. 30 National Oceanic and Atmospheric Administration. (n.d.). Glossary: Endangered Species Act. https://www.fisheries.noaa.gov/laws-and-policies/glossary-endangered-speciesact#:~:text=A%20threatened%20species%20is%20defined%20under%20the%20ESA,threatened%20or%20endange red%20are%20called%20%E2%80%9C%20listed%20species.%E2%80%9D
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 55 The Clean Water Act
The federal Clean Water Act (CWA) employs regulatory and non-regulatory tools to reduce direct pollutant discharges into waterways, finance municipal wastewater treatment facilities, and manage polluted runoff. These tools are employed to achieve the broader goal of restoring and maintaining the chemical, physical, and biological integrity of the nation’s surface waters so that they can support “the protection and propagation of fish, shellfish, and wildlife and recreation in and on the water.” Evolution of CWA programs over the last decade has included a shift from a program-by-program, source-by-source, and pollutant-by-pollutant approach to more holistic watershed-based strategies.
Under the watershed approach, equal emphasis is placed on protecting healthy waters and restoring impaired ones. A full array of issues is addressed, not just those subject to CWA regulatory authority.
Involvement of stakeholder groups in the development and implementation of strategies for achieving and maintaining water quality and other environmental goals is a hallmark of this approach.
FEMA hazard mitigation project grant applications require full compliance with applicable federal acts.
Any action identified in this plan that falls within the scope of this act will need to meet its requirements.
National Flood Insurance Program
The National Flood Insurance Program (NFIP) provides federally backed flood insurance in exchange for communities enacting floodplain regulations. Participation and good standing under NFIP are prerequisites to grant funding eligibility under the Robert T. Stafford Act. Santa Clara County and all of the partner cities for this plan participate in the NFIP and have adopted regulations that meet the NFIP requirements. At the time of the preparation of this plan, all participating jurisdictions in the partnership were in good standing and in full compliance with the minimum requirements of the NFIP.
Community Rating System
The Community Rating System (CRS) is a voluntary incentive program for communities that participate in the NFIP and adopt and enforce floodplain management practices that exceed minimum requirements.
Flood insurance premium discounts reflect the ways in which the community meets the following goals of the program:
Reduce and avoid flood damage to insurable property.
Strengthen and support the insurance aspects of the National Flood Insurance Program. Foster comprehensive floodplain management.
Participating in the CRS program not only encourages communities to reduce the risk to life and property from flooding through a proactive floodplain management program, but provides a clear, monetary incentive for residents for supporting mitigation activities. Many planning partners participate in the CRS.
Many planning partners participate in the CRS. The planning partners discussed using this plan to meet CRS requirements as well. Ultimately, it was decided that Santa Clara Valley Water will lead the development of a separate Floodplain Management Plan specifically dedicated towards this goal, allowing planning partners that participate in the CRS program to maintain or enhance their CRS classifications. Relevant information from this Hazard Mitigation Plan will be incorporated into the Floodplain Management Plan.
Coastal Zone Management Act
The national Coastal Zone Management Act requires federal agencies to conduct their planning, management, development, and regulatory activities in a manner consistent to the maximum extent practicable with the policies of state Coastal Zone Management (CZM) programs. State CZM lead agencies have the authority to review federal actions for consistency with their federally approved CZM programs.
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 56 In California, the California Coastal Commission, the Bay Conservation and Development Commission, and the California Coastal Conservancy are the three CZM agencies empowered to conduct federal consistency reviews. The informational and procedural requirements for CZM federal consistency reviews are prescribed by federal regulations (15 CFR 930). Any action identified in this plan that falls within the scope of this act will need to meet its requirements.
National Incident Management System
The National Incident Management System is a systematic approach for government, nongovernmental organizations, and the private sector to work together to manage incidents involving hazards. The system provides a flexible but standardized set of incident management practices. Incidents typically begin and end locally, and they are managed at the lowest possible geographical, organizational, and jurisdictional level. In other instances, success depends on the involvement of multiple jurisdictions, levels of government, functional agencies, and emergency-responder disciplines. These instances necessitate coordination across this spectrum of organizations. Communities using the National Incident Management System follow a comprehensive national approach that improves the effectiveness of emergency management and response personnel across the full spectrum of potential hazards (including natural hazards, terrorist activities, and other human-caused disasters) regardless of size or complexity.
Although participation is voluntary, federal departments and agencies are required to make adoption of NIMS by local and state jurisdictions a condition to receive federal preparedness grants and awards. The content of this plan is considered to be a viable support tool for any phase of emergency management.
The NIMS program is considered as a response function, and information in this hazard mitigation plan can support the implementation and update of all NIMS-compliant plans within the planning area.
Americans with Disabilities Act and Amendments
The Americans with Disabilities Act (ADA) seeks to prevent discrimination against people with disabilities in employment, transportation, public accommodation, communications, and government activities. The most recent amendments became effective in January 2009 (P.L. 110-325). Title II of the ADA deals with compliance with the act in emergency management and disaster-related programs, services, and activities. It applies to state and local governments as well as third parties, including religious entities and private nonprofit organizations.
The ADA has implications for sheltering requirements and public notifications. During an emergency alert, officials must use a combination of warning methods to ensure that all residents have any necessary information. Those with hearing impairments may not hear radio, television, sirens, or other audible alerts, while those with visual impairments may not see flashing lights or visual alerts. Two stand-alone technical documents have been issued for shelter operators to meet the needs of people with disabilities. These documents address physical accessibility as well as medical needs and service animals.
The ADA also intersects with disaster preparedness programs in regard to transportation, social services, temporary housing, and rebuilding. Persons with disabilities may require additional assistance in evacuation and transit (such as vehicles with wheelchair lifts or paratransit buses). Evacuation and other response plans should address the unique needs of residents. Local governments may be interested in implementing a special-needs registry to identify the home addresses, contact information, and needs for residents who may require more assistance.
FEMA hazard mitigation project grant applications require full compliance with applicable federal acts.
Any action identified in this plan that falls within the scope of this act will need to meet its requirements.
Civil Rights Act of 1964
The Civil Rights Act of 1964 prohibits discrimination based on race, color, religion, sex, or national origin and requires equal access to public places and employment. The act is relevant to emergency management and hazard mitigation in that it prohibits local governments from favoring the needs of one population group over another.
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 57 Local government and emergency response must ensure the continued safety and well-being of all residents equally, to the extent possible. FEMA hazard mitigation project grant applications require full compliance with applicable federal acts. Any action identified in this plan that falls within the scope of this act will need to meet its requirements.
Rural Development Program
The mission of the U.S. Department of Agriculture (USDA) Rural Development Program is to help improve the economy and quality of life in rural America. The program provides project financing and technical assistance to help rural communities provide the infrastructure needed by rural businesses, community facilities, and households. The program addresses rural America’s need for basic services, such as clean running water, sewage and waste disposal, electricity, and modern telecommunications and broadband. Loans and competitive grants are offered for various community and economic development projects and programs, such as the development of essential community facilities including fire stations. Some of the actions identified in this plan may be eligible for funding available under this program.
Community Development Block Grant Disaster Resilience Program In response to disasters, Congress may appropriate additional funding for the U.S. Department of Housing and Urban Development Community Development Block Grant programs to be distributed as Disaster Recovery grants (CDBG-DR). These grants can be used to rebuild affected areas and provide seed money to start the recovery process. CDBG-DR assistance may fund a broad range of recovery activities, helping communities and neighborhoods that otherwise might not recover due to limited resources. CDBG-DR grants often supplement disaster programs of FEMA, the Small Business Administration, and the U.S. Army Corps of Engineers. Housing and Urban Development generally awards noncompetitive, nonrecurring CDBG-DR grants by a formula that considers disaster recovery needs unmet by other federal disaster assistance programs. To be eligible for CDBG-DR funds, projects must meet the following criteria:
Address a disaster-related impact (direct or indirect) in a presidentially declared county for the covered disaster.
Be a CDBG-eligible activity (according to regulations and waivers). Meet a national objective.
Incorporating preparedness and mitigation into these actions is encouraged, as the goal is to rebuild in ways that are safer and stronger. CDGB-DR funding is a potential alternative source of funding for actions identified in this plan.
Community Development Block Grant Mitigation
The Community Development Block Grant Mitigation (CDBG-MIT) program was developed to support communities impacted by recent disasters in carrying out strategic and high-impact mitigation actions to reduce losses from future events. Congress may appropriate additional CDBG-MIT funding for the U.S.
Department of Housing and Urban Development following a disaster event. The goals of CDBG-MIT funding are:
Support data-informed investments, focusing on repetitive loss of property and critical infrastructure;
Build capacity to comprehensively analyze disaster risks and update hazard mitigation plans; Support the adoption of policies that reflect local and regional priorities that will have long-lasting effects on community risk reduction, including risk reduction to community lifelines and decreasing future disaster costs; and
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 58 Maximize the impact of funds of encouraging leverage, private/public partnerships, and coordination with other federal dollars.
This would be a potential post-disaster financial capability of jurisdictions covered in this plan which could be put towards implementing the identified mitigation actions.
Emergency Watershed Program
The USDA Natural Resources Conservation Service administers the Emergency Watershed Protection Program, which responds to emergencies created by natural disasters. Eligibility for assistance is not dependent on a national emergency declaration. The program is designed to help people and conserve natural resources by relieving imminent hazards to life and property caused by floods, fires, windstorms, and other natural occurrences. The Emergency Watershed Protection is an emergency recovery program.
Financial and technical assistance are available for the following activities:30 F30F 31 Remove debris from stream channels, road culverts, and bridges. Reshape and protect eroded banks.
Correct damaged drainage facilities.
Establish cover on critically eroding lands.
Repair levees and structures.
Repair conservation practices.
This federal program could be a possible funding source for actions identified in this plan.
Presidential Executive Orders 11988 and 13690
Executive Order 11988 requires federal agencies to avoid to the extent possible the long and short-term adverse impacts associated with the occupancy and modification of floodplains and to avoid direct and indirect support of floodplain development wherever there is a practicable alternative. It requires federal agencies to provide leadership and take action to reduce the risk of flood loss, minimize the impact of floods on human safety, health, and welfare, and restore and preserve the natural and beneficial values of floodplains. The requirements apply to the following activities31F31 F 32:
Acquiring, managing, and disposing of federal lands and facilities. Providing federally undertaken, financed, or assisted construction and improvements. Conducting federal activities and programs affecting land use, including but not limited to water and related land resources planning, regulation, and licensing.
Executive Order 13690 expands Executive Order 11988 and acknowledges that the impacts of flooding are anticipated to increase over time due to the effects of climate change and other threats. It mandates a federal flood risk management standard to increase resilience against flooding and help preserve the natural values of floodplains. This standard expands management of flood issues from the current base flood level to a higher vertical elevation and corresponding horizontal floodplain when federal dollars are involved in a project.
31 National Resources Conservation Service. (n.d.). Emergency Watershed Protection. https://www.nrcs.usda.gov/programs-initiatives/ewp-emergency-watershed-protection/kentucky/emergencywatershed-protection 32 Federal Emergency Management Agency. (2015, October 8). Guidelines for Implementing Executive Order 11988. https://www.fema.gov/sites/default/files/documents/fema_implementing-guidelines-EO11988-13690_10082015.pdf
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 59 The goal is to address current and future flood risk and ensure that projects funded with taxpayer dollars last as long as intended.32F32F
33 All actions identified in this plan will seek full compliance with all applicable presidential executive orders.
Presidential Executive Order 11990
Executive Order 11990 requires federal agencies to provide leadership and take action to minimize the destruction, loss, or degradation of wetlands, and to preserve and enhance the natural and beneficial values of wetlands. The requirements apply to the following activities:3 F3F 34 Acquiring, managing, and disposing of federal lands and facilities. Providing federally undertaken, financed, or assisted construction and improvements. Conducting federal activities and programs affecting land use, including but not limited to water and related land resources planning, regulation, and licensing.
All actions identified in this plan will seek full compliance with all applicable presidential executive orders.
Emergency Relief for Federally Owned Roads Program
The U.S. Forest Service’s Emergency Relief for Federally Owned Roads Program was established to assist federal agencies with repair or reconstruction of tribal transportation facilities, federal lands transportation facilities, and other federally owned roads that are open to public travel and have suffered serious damage by a natural disaster over a wide area or by a catastrophic failure. The program funds both emergency and permanent repairs.34F34F
35 Eligible activities under this program meet some of the goals and objectives for this plan and the program is a possible funding source for actions identified in this plan.
U.S. Army Corps of Engineers Programs
The U.S. Army Corps of Engineers has several civil works authorities and programs related to flood risk and flood hazard management:
Floodplain Management Services are 100-percent federally funded technical services such as development and interpretation of site-specific data related to the extent, duration, and frequency of flooding. Special studies may be conducted to help a community understand and respond to flood risk. These may include flood hazard evaluation, flood warning and preparedness, or flood modeling.
For more extensive studies, the Corps of Engineers offers a cost-shared program called Planning Assistance to States and Tribes. Studies under this program generally range from $25,000 to $100,000, with the local jurisdiction providing 50 percent of the cost. The Corps of Engineers has several cost-shared programs (typically 65 percent federal and 35 percent non-federal) aimed at developing, evaluating, and implementing structural and nonstructural capital projects to address flood risks at specific locations or within a specific watershed:
33 Obama White House. (2015, January 30). Executive Order – Establishing a Federal Flood Risk Management Standard and a Process for Further Soliciting and Considering Stakeholder Input. https://obamawhitehouse.archives.gov/the-press-office/2015/01/30/executive-order-establishing-federal-flood-riskmanagement-standard-and34 National Archives. (n.d.). § 9.4 Definitions. https://www.ecfr.gov/current/title-44/chapter-I/subchapter-A/part9/section-9.4 35 Federal Highway Administration. (n.d.). Fact Sheets, Emergency Relief Program. https://www.fhwa.dot.gov/bipartisan-infrastructurelaw/er_fact_sheet.cfm#:~:text=The%20BIL%20continues%20the%20Emergency%20Relief%20program%2C%20whi ch,disasters%20or%20catastrophic%20failure%20from%20an%20external%20cause.
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 60 ▪ The Continuing Authorities Program for smaller-scale projects includes Section 205 for Flood Control, with a $7 million federal limit and Section 14 for Emergency Streambank Protection with a $1.5 million federal limit. These can be implemented without specific authorization from Congress.
▪ Larger scale studies, referred to as General Investigations, and projects for flood risk management, for ecosystem restoration or to address other water resource issues, can be pursued through a specific authorization from Congress and are cost-shared, typically at 65 percent federal and 35 percent non-federal.
▪ Watershed Management planning studies can be specifically authorized and are cost-shared at 50 percent federal and 50 percent non-federal.
The Corps of Engineers provides emergency response assistance during and following natural disasters. Public Law 84-99 enables the Corps to assist state and local authorities in flood fight activities and cost share in the repair of flood protective structures. Assistance afforded under PL 84-99 is broken down into the following categories:
▪ Preparedness: The Flood Control and Coastal Emergency Act establishes an emergency fund for preparedness for emergency response to natural disasters; for flood fighting and rescue operations; for rehabilitation of flood control and hurricane protection structures.
Funding for Corps of Engineers emergency response under this authority is provided by Congress through the annual Energy and Water Development Appropriation Act. Disaster preparedness activities include coordination, planning, training and conduct of response exercises with local, state, and federal agencies.
▪ Response Activities: PL 84-99 allows the Corps of Engineers to supplement state and local entities in flood-fighting for urban and other non-agricultural areas under certain conditions (Engineering Regulation 500-1-1 provides specific details). All flood-fight efforts require a Project Cooperation Agreement (PCA) signed by the public sponsor and a requirement for the sponsor to remove all flood-fight material after the flood has receded. PL 84-99 also authorizes emergency water support and drought assistance in certain situations and allows for “advance measures” assistance to prevent or reduce flood damage conditions of imminent threat of unusual flooding.
▪ Rehabilitation: Under PL 84-99, an eligible flood protection system can be rehabilitated if damaged by a flood event. The flood system would be restored to its pre-disaster status at no cost to the federal system owner, and at 20-percent cost to the eligible non-federal system owner. All systems eligible for PL 84-99 rehabilitation assistance have to be in the Rehabilitation and Inspection Program prior to the flood event. Acceptable operation and maintenance by the public levee sponsor are verified by levee inspections conducted by the Corps on a regular basis. The Corps has the responsibility to coordinate levee repair issues with interested federal, state, and local agencies following natural disaster events where flood control works are damaged.
All of these authorities and programs are available to the planning partners to support any intersecting mitigation actions.
5.9.2 State
Alquist-Priolo Earthquake Fault Zoning Act
The Alquist-Priolo Earthquake Fault Zoning Act was enacted in 1972 to mitigate the hazard of surface faulting to structures for human occupancy. The Alquist-Priolo Earthquake Fault Zoning Act’s main purpose is to prevent construction of buildings used for human occupancy on the surface trace of active faults. Before a new project is permitted, cities and counties require a geologic investigation to demonstrate that proposed buildings will not be constructed on active faults.
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 61 The act addresses only the hazard of surface fault rupture and is not directed toward other earthquake hazards, such as liquefaction or seismically induced landslides. The law requires geologists from the State of California to establish regulatory zones around the surface traces of active faults and to issue appropriate maps. The maps are distributed to all affected cities, counties, and state agencies for their use in planning and controlling new or renewed construction. Local agencies must regulate most development projects within the zones. Projects include all land divisions and most structures for human occupancy. All seismic hazard mitigation actions identified in this plan will seek full compliance with the Alquist-Priolo Earthquake Fault Zoning Act.
California General Planning Law
California state law requires that every county and city prepare and adopt a comprehensive long-range plan to serve as a guide for community development. The general plan expresses the community’s goals, visions, and policies relative to future land uses, both public and private. The general plan is mandated and prescribed by state law (Cal. Gov. Code §65300 et seq.) and forms the basis for most local government land use decision-making.
The plan must consist of an integrated and internally consistent set of goals, policies, and implementation measures. In addition, the plan must focus on issues of the greatest concern to the community and be written in a clear and concise manner. City and county actions, such as those relating to land use allocations, annexations, zoning, subdivision and design review, redevelopment, and capital improvements, must be consistent with the plan.
All municipal planning partners to this plan have general plans that are currently compliant with this law and have committed to integrating this mitigation plan with their general plans through provisions referenced below (AB-2140 and SB-379).
California Environmental Quality Act
The California Environmental Quality Act (CEQA) was passed in 1970, shortly after the federal government enacted the National Environmental Policy Act, to institute a statewide policy of environmental protection. CEQA requires state and local agencies in California to follow a protocol of analysis and public disclosure of the potential environmental impacts of development projects. CEQA makes environmental protection a mandatory part of every California state and local agency’s decisionmaking process.
CEQA establishes a statewide environmental policy and mandates actions all state and local agencies must take to advance the policy. Jurisdictions conduct analysis of the project to determine if there are potentially significant environmental impacts, identify mitigation measures, and possible project alternatives by preparing environmental reports for projects that requires CEQA review. This environmental review is required before an agency takes action on any policy, program, or project.
Santa Clara County has sought exemption from CEQA for the Hazard Mitigation Plan based on four different sections of the CEQA Guidelines:
Section 15183(d): “The project is consistent with…a general plan of a local agency, and an EIR was certified by the lead agency for the...general plan.” Section 15262: “A project involving only feasibility or planning studies for possible future actions which the agency, board or commission has not approved, adopted, or funded does not require the preparation of an EIR or negative declaration but does require consideration of environmental factors. This section does not apply to the adoption of a plan that will have a legally binding effect on later activities.”
Section 15306: “(Categorical Exemption) Class 6 consists of basic data collection, research, experimental management, and resource evaluation activities which do not result in a serious or major disturbance to an environmental resource. These may be strictly for information gathering
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 62 purposes, or as part of a study leading to an action which a public agency has not yet approved, adopted, or funded.”
Section 15601(b)(3): “...CEQA applies only to projects which have the potential for causing a significant effect on the environment. Where it can be seen with certainty that there is no possibility that the activity in question may have a significant effect on the environment, the activity is not subject to CEQA.”
Planning partners may seek exemption at their discretion.
California Coastal Management Program
The California Coastal Management Program under the California Coastal Act requires each city or county lying wholly or partly within the coastal zone to prepare a local coastal plan. The specific contents of such plans are not specified by state law, but they must be certified by the Coastal Commission as consistent with policies of the Coastal Act (Public Resources Code, Division 20). The Coastal Act has provisions relating to geologic hazards but does not mention tsunamis specifically. Section 30253(1) of the Coastal Act states that new development shall minimize risks to life and property in areas of high geologic, flood, and fire hazard. Development should be prevented or limited in high hazard areas whenever possible. However, where development cannot be prevented or limited, land use density, building value, and occupancy should be kept at a minimum.
There are identified coastal zones in the Santa Clara County Operational Area and affected planning partners have developed local coastal plans to address them. Any mitigation project identified in this plan that intersects the mapped coastal zone will be consistent with the recommendations of the local coastal plan.
California State Assembly Bills
Assembly Bill 162: Flood Planning, Chapter 369, Statutes of 2007 This California State Assembly Bill (AB) passed in 2007 requires cities and counties to address floodrelated matters in the land use, conservation, and safety and housing elements of their general plans.
The land use element must identify and annually review the areas covered by the general plan that are subject to flooding as identified in floodplain mapping by either FEMA or the Department of Water Resources (DWR). During the next revision of the housing element on or after January 1, 2009, the conservation element of the general plan must identify rivers, creeks, streams, flood corridors, riparian habitat, and land that may accommodate floodwater for groundwater recharge and stormwater management. The safety element must identify information regarding flood hazards, including:
Flood hazard zones;
Maps published by FEMA, DWR, the U.S. Army Corps of Engineers, the Central Valley Flood.
Protection Board, and CalOES;
Historical data on flooding; and
Existing and planned development in flood hazard zones.
The general plan must establish goals, policies, and objectives to protect from unreasonable flooding risks, including:
Avoiding or minimizing the risks of flooding new development; Evaluating whether new development should be located in flood hazard zones; and Identifying construction methods to minimize damage.
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 63 Assembly Bill 2140: General Plans—Safety Element, Chapter 739, Statutes of 2006 This bill allows jurisdictions to be eligible for state funding to cover the local match of public assistance costs for recovery activities after hazard events if the local jurisdiction incorporates their Local Hazard Mitigation Plan into the safety element of their general plan. In addition, this bill requires Cal OES to give preference for federal mitigation funding to cities and counties that have adopted local hazard mitigation plans. The intent of the bill is to encourage cities and counties to create and adopt hazard mitigation plans.
The County OEM has worked with the safety element team throughout 2022 and 2023 in updating the Safety Element, to ensure the County is maximizing their future funding opportunities to reduce risk in the County and comply with Assembly Bill 2140 (2006), which affords the county additional benefits under the California Disaster Assistance Act. The Multi-Jurisdictional Hazard Mitigation Plan will be incorporated into the Safety Element as the Safety Element update comes to a completion and is presented to the Board of Supervisors for Adoption.
Assembly Bill 70: Flood Liability, Chapter Number 367, Statutes of 2007 This bill provides that a city or county may be required to contribute a fair and reasonable share to compensate for property damage caused by a flood to the extent that it has increased the state’s exposure to liability for property damage by unreasonably approving new development in a previously undeveloped area that is protected by a state flood control project, unless the city or county meets specified requirements.
Assembly Bill 32: The California Global Warming Solutions Act This bill addresses greenhouse gas emissions. It identifies the following potential adverse impacts of global warming:
the exacerbation of air quality problems, a reduction in the quality and supply of water to the state from the Sierra snowpack, a rise in sea levels resulting in the displacement of thousands of coastal businesses and residences, damage to marine ecosystems and the natural environment, and an increase in the incidences of infectious diseases, asthma, and other human health-related problems.
AB 32 establishes a state goal of reducing greenhouse gas emissions to 1990 levels by 2020 (a reduction of approximately 25 percent from forecast emission levels), with further reductions to follow. The law requires the state Air Resources Board to do the following:35F35F 36 Establish a program to track and report greenhouse gas emissions. Approve a scoping plan for achieving the maximum technologically feasible and cost-effective reductions from sources of greenhouse gas emissions.
Adopt early reduction measures to begin moving forward. Adopt, implement, and enforce regulations—including market mechanisms such as “cap andtrade” programs—to ensure that the required reductions occur.
The Air Resources Board recently adopted a statewide greenhouse gas emissions limit and an emissions inventory, along with requirements to measure, track, and report greenhouse gas emissions by the industries it determined to be significant sources of greenhouse gas emissions. 36 California Air Resources Board. (2018, September 28). AB 32 Global Warming Solutions Act of 2006. https://ww2.arb.ca.gov/resources/fact-sheets/ab-32-global-warming-solutions-act-2006
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 64 Assembly Bill 2800: Climate Change: Infrastructure Planning This California State Assembly bill, in effect through July 1, 2020, requires state agencies to consider the current and future impacts of climate change when planning, designing, building, operating, maintaining, and investing in state infrastructure. The bill requires the agency to establish a climate-safe infrastructure working group by July 1, 2017, to examine how to integrate scientific data concerning projected climate change impacts into state infrastructure engineering.
Assembly Bill 38: Fire Safety: Low-Cost Retrofits: Regional Capacity Review: Wildfire Mitigation
The Governor approved assembly bill 38 in October 2019 expanding pre-existing obligations to review regional capacity to improve forest health, fire resilience, and safety as well as provide a prescribed disclosure notice to buyers of property informing them of their fire home hardening options. In addition, it authorized Cal OES and CALFIRE to jointly develop a wildfire mitigation program now known as the “Home Hardening Program.” This effort is intended to encourage cost-effective wildfire resilience measures by providing financial assistance for retrofits, hardening, and the creation of defensible space. 1998 Natural Hazard Disclosure Act
The Natural Hazard Disclosure Act, which became effective in June 1998, requires sellers to provide home buyers with a natural hazard disclosure report (NHD) in order to sell a home in a natural hazard zone. Failure to comply with this act may result in the buyer or agent being liable for any damage experienced by the buyer. There are six main hazards required to be disclosed in an NHD:36F36F 37 A special flood hazard area
An area of potential flooding on a dam failure inundation map A very high fire severity zone
A wildland area that may contain substantial forest fire risks and hazards An earthquake fault zone
A seismic hazard zone
California State Senate Bills
Senate Bill 97
Senate Bill 97, enacted in 2007, amends CEQA to clearly establish that greenhouse gas emissions and the effects of greenhouse gas emissions are appropriate subjects for CEQA analysis. It directs the Governor’s Office of Planning and Research to develop draft CEQA guidelines for the mitigation of greenhouse gas emissions or their effects by July 1, 2009, and directs the California Natural Resources Agency to certify and adopt the CEQA Guidelines by January 1, 2010.
Senate Bill 1000 General Plan Amendments: Safety and Environmental Justice Elements Senate Bill 1000 amends California’s Planning and Zoning Law in two ways:
The original law established requirements for initial revisions of general plan safety elements to address flooding, fire, and climate adaptation and resilience. It also required subsequent review and revision as necessary based on new information. Senate Bill 1000 specifies that the 37 California Association of Realtors. (n.d.). Natural Hazard Disclosure Statement. https://www.car.org/- /media/CAR/Documents/Transaction-Center/PDF/QUICK-GUIDES/Quick-Guide--Natural-Hazard-Disclsoure-NHDStatement-REVISED-52022.pdf
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 65 subsequent reviews and revision based on new information are required to address only flooding and fires (not climate adaptation and resilience).
Senate Bill 1000 adds a requirement that, upon adoption or revision of any two other general plan elements on or after January 1, 2018, an environmental justice element be adopted for the general plan or environmental justice goals, policies and objectives be incorporated into other elements of the plan.
Senate Bill 1241: General Plans: Safety Element—Fire Hazard Impacts In 2012, Senate Bill 1241 was enacted, requiring that all future General Plans address fire risk in state responsibility areas and very high fire hazard severity zones in their safety element. In addition, the bill requires cities and counties to make certain findings regarding available fire protection and suppression services before approving a tentative map or parcel map.
Senate Bill 379: General Plans: Safety Element—Climate Adaptation Senate Bill 379 builds on the flood planning inclusions into the safety and housing elements and the hazard mitigation planning safety element inclusions in General Plans outlined in AB 162 and AB 2140.
Senate Bill 379 specifically focuses on a new requirement that cities and counties include climate adaptation and resiliency strategies in the safety element of their General Plans beginning January 1, 2017. In addition, this bill requires general plans to include a set of goals, policies, and objectives, and specified implementation measures based on the conclusions drawn from climate adaptation research and recommendations.
This update process for this hazard mitigation plan was conducted with the intention of full compliance with this bill. However, at the time of the update, there was no clear guidance from the state on what constitutes full compliance or what protocol is to be used to determine compliance. When such guidance has been established, the planning partners will submit this plan or its subsequent updates to the state for review and approval.
Senate Bill 190: Fire Safety: Building Standards: Defensible Space Program In October 2019, Senate Bill 190 amended the Government Code and Health and Safety Code to build a common understanding of site and structure fire risk reduction measures. Among other things, the bill authorized the Office of the State Fire Marshall to develop a model defensible space program which would be available for city and county code enforcement officials to utilize. Additionally, it directed the Office of the State Fire Marshall to develop and make publicly available a Wildland-Urban Interface Fire Safety Building Standards compliance training intended for local building officials, builders, and fire service personnel.37 F37F
38 California State Building Code
California Code of Regulations Title 24 (CCR Title 24), also known as the California Building Standards Code, is a compilation of building standards from three sources:
Building standards that have been adopted by state agencies without change from building standards contained in national model codes.
Building standards that have been adopted and adapted from the national model code standards to meet California conditions.
Building standards authorized by the California legislature that constitute extensive additions not covered by the model codes adopted to address particular California concerns. 38 California Legislative Information. (2019, October 2). SB-190 Fire Safety: Building Standards: Defensible Space Program. Bill Text - SB-190 Fire safety: building standards: defensible space program. (ca.gov)
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 66 The state Building Standards Commission is authorized by California Building Standards Law (Health and Safety Code Sections 18901 through 18949.6) to administer the processes related to the adoption, approval, publication, and implementation of California’s building codes. These building codes serve as the basis for the design and construction of buildings in California. The national model code standards adopted into Title 24 apply to all occupancies in California, except for modifications adopted by state agencies and local governing bodies. Since 1989, the Building Standards Commission has published new editions of Title 24 every 3 years. All municipal planning partners to this plan have adopted building codes that are in full compliance with the California State Building Code.
California has also passed the first green building code in the Nation, known as the California Green Building Standards Code (CALGreen). CALGreen establishes new green building standards in order to promote sustainable development. The goals of the program include:
Reduce greenhouse gas emissions from buildings.
Promote environmentally responsible, cost-effective, healthier places to live and work. Reduce energy and water consumption.
Respond to the environmental directives of the administration.
Standardized Emergency Management System
CCR Title 19 establishes the Standardized Emergency Management System to standardize the response to emergencies involving multiple jurisdictions. The system is intended to be flexible and adaptable to the needs of all emergency responders in California. It requires emergency response agencies to use basic principles and components of emergency management. Local governments must use the Standardized Emergency Management System by December 1, 1996, to be eligible for state funding of responserelated personnel costs under CCR Title 19 (Sections 2920, 2925 and 2930). The roles and responsibilities of individual agencies contained in existing laws or the state emergency plan are not superseded by these regulations. This hazard mitigation plan is considered to be a support document for all phases of emergency management, including those associated with SEMS.
California State Hazard Mitigation Plan
Under the DMA, California must adopt a federally approved state multi-hazard mitigation plan to be eligible for certain disaster assistance and mitigation funding. California has elected to develop an enhanced plan, which makes it eligible for additional mitigation funding. The State Hazard Mitigation Plan (SHMP) is the State’s primary hazard mitigation guidance. It incorporates:
An updated analysis of the state’s historical and current hazards. Hazard mitigation goals and objectives.
Hazard Mitigation strategies and actions.
The California Governor’s Office of Emergency Services (Cal OES) is responsible for leading the plan update in coordination with key planning stakeholders and sources of information. The 2018 SHMP is being updated at the time of this plan’s update to reflect changing conditions and add new information as well as incorporate the new FEMA planning policy guidance.
Under 44 CFR Section 201.6, local hazard mitigation plans must be consistent with their state’s hazard mitigation plan. In updating this plan, the Steering Committee reviewed the California State Hazard Mitigation Plan to identify key relevant state plan elements.
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 67 Governor’s Executive Order S-13-08
Governor’s Executive Order S-13-08 enhances the state’s management of climate impacts from sea level rise, increased temperatures, shifting precipitation and extreme weather events. There are four key actions in the executive order:
Initiate California’s first statewide climate change adaptation strategy to assess expected climate change impacts, identify where California is most vulnerable, and recommend adaptation policies by early 2009. This effort will improve coordination within state government so that better planning can more effectively address climate impacts on human health, the environment, the state’s water supply and the economy.
Request that the National Academy of Science establish an expert panel to report on sea level rise impacts in California, to inform state planning and development efforts. Issue interim guidance to state agencies for how to plan for sea level rise in designated coastal and floodplain areas for new projects.
Initiate a report on critical infrastructure projects vulnerable to sea level rise.
5.9.3 Local
Plans, Reports, and Codes
Plans, reports, and other technical information were identified and provided directly by participating jurisdictions and stakeholders or were identified through independent research by the planning consultant. These documents were reviewed to identify the following:
Existing jurisdictional and special district capabilities. Needs and opportunities to develop or enhance capabilities, which may be identified within the local mitigation strategies.
Mitigation-related goals or objectives considered during the development of the overall goals and objectives.
Proposed, in-progress, or potential mitigation projects, actions, and initiatives to be incorporated into the updated mitigation strategies.
The following local regulations, codes, ordinances, and plans were reviewed in order to develop complementary and mutually supportive goals, objectives, and mitigation strategies that are consistent across local and regional planning and regulatory mechanisms:
▪ General Plans (Housing Elements, Safety Elements).
▪ Building Codes.
▪ Zoning and Subdivision Ordinances.
▪ NFIP Flood Damage Prevention Ordinances.
▪ Stormwater Management Plans.
▪ Emergency Management and Response Plans.
▪ Land Use and Open Space Plans.
▪ Climate Action Plans.
▪ Capability Assessment.
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 68 All participating jurisdictions and special districts compiled an inventory and analysis of existing authorities and capabilities called a “capability assessment.” A capability assessment creates an inventory of a jurisdiction’s mission, programs, and policies, and evaluates its capacity to carry them out.
This assessment identifies potential gaps in the jurisdiction’s capabilities and opportunities to expand and improve upon existing capabilities.
The planning partners views all core jurisdictional and special district capabilities as fully adaptable to meet an organization’s needs. Every code can be amended, and every plan can be updated. Such adaptability is itself considered to be an overarching capability. If the capability assessment identified an opportunity to add a missing core capability or expand an existing one, then doing so has been selected as an action in the jurisdiction’s action plan, which is included in the individual annexes presented in Volume 2 of this plan.
Capability assessments for each planning partner are presented in the jurisdictional and special district annexes in Volume 2 of this plan. The sections below describe the specific capabilities evaluated under the assessment.
Legal and Regulatory Capabilities
Jurisdictions have the ability to develop policies and programs and to implement rules and regulations to protect and serve residents. Local policies are typically identified in a variety of community plans, implemented via a local ordinance, and enforced through a governmental body.
Jurisdictions regulate land use through the adoption and enforcement of zoning, subdivision, and land development ordinances, building codes, building permit ordinances, floodplain, and stormwater management ordinances. When effectively prepared and administered, these regulations can lead to hazard mitigation.
Fiscal Capabilities
Assessing a jurisdiction’s or special district’s fiscal capability provides an understanding of the ability to fulfill the financial needs associated with hazard mitigation projects. This assessment identifies both outside resources, such as grant-funding eligibility, and local authority to generate internal financial capability, such as through impact fees.
Administrative and Technical Capabilities
Legal, regulatory, and fiscal capabilities provide the backbone for successfully developing a mitigation strategy; however, without appropriate personnel, the strategy may not be implemented. Administrative and technical capabilities focus on the availability of personnel resources responsible for implementing all the facets of hazard mitigation. These resources include technical experts, such as engineers and scientists, as well as personnel with capabilities that may be found in multiple departments, such as grant writers.
NFIP Compliance
Flooding is the costliest natural hazard in the United States and, with the promulgation of recent federal regulation, homeowners throughout the country are experiencing increasingly high flood insurance premiums. Community participation in the NFIP opens up opportunity for additional grant funding associated specifically with flooding issues. Assessment of the jurisdiction’s current NFIP status and compliance provides planners with a greater understanding of the local flood management program, opportunities for improvement, and available grant funding opportunities.
Public Outreach Capability
Regular engagement with the public on issues regarding hazard mitigation provides an opportunity to directly interface with community members. Assessing this outreach and education capability illustrates
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 5: Santa Clara County Operational Area Profile 69 the connection between the government and community members, which opens a two-way dialogue that can result in a more resilient community based on education and public engagement.
Participation in Other Programs
Other programs, such as the Community Rating System, StormReady, and Firewise, enhance a jurisdiction’s ability to mitigate, prepare for, and respond to natural hazards. These programs indicate a jurisdiction’s desire to go beyond minimum requirements set forth by local, state, and federal regulations in order to create a more resilient community. These programs complement each other by focusing on communication, mitigation, and community preparedness to save lives and minimize the impact of natural hazards on a community.
Development and Permitting Capability
Identifying previous and future development trends is achieved through a comprehensive review of permitting since completion of the previous plan and in anticipation of future development. Tracking previous and future growth in potential hazard areas provides an overview of increased exposure to a hazard within a community.
Adaptive Capacity
An adaptive capacity assessment evaluates a jurisdiction’s ability to anticipate impacts from future conditions. By looking at public support, technical adaptive capacity, and other factors, jurisdictions identify their core capability for resilience against issues such as sea level rise. The adaptive capacity assessment provides jurisdictions with an opportunity to identify areas for improvement by ranking their capacity high, medium, or low.
Expanding and Improving Mitigation Capabilities
Both pre- and post-disaster mitigation capabilities change over time. The intent of this mitigation plan is to evaluate current mitigation capabilities and identify if there are any gaps which could be further addressed. In Volume 2 of this plan, in addition to an individual capability assessment, there is a discussion of the capabilities which could be expanded upon for each participant. County items, such as increasing funding for community education and outreach including translated materials as well as funding regional planning and coordination, serve as examples of what this looks like. If there are any challenges or limitations for each participant, they have stated so in the in their respective annex.
Integration Opportunity
The assessment looked for opportunities to integrate this mitigation plan with the legal/regulatory capabilities identified. Capabilities were identified as integration opportunities if they can support or enhance the actions identified in this plan or be supported or enhanced by components of this plan.
Planning partners considered actions to implement this integration as described in the jurisdictional and special district annexes in Volume 2 of this plan.
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 6: Identified Hazards of Concern and Risk Assessment 70 6 Identified Hazards of Concern and Risk
Assessment
Risk assessment is the process of measuring the potential loss of life, personal injury, economic injury, and property damage resulting from identified hazards. It allows emergency management personnel to establish early response priorities by identifying potential hazards and vulnerable assets. The process focuses on the following elements:
Hazard identification: Use all available information to determine what types of hazards may affect a jurisdiction, how often they can occur, and their potential severity. Exposure identification: Estimate the total number of people and properties in the jurisdiction that are likely to experience a hazard event if it occurs.
Vulnerability identification and loss estimation: Assess the impact of hazard events on the people, property, environment, economy, and lands of the region, including estimates of the cost of potential damage or cost that can be avoided by mitigation.
The risk assessment for this hazard mitigation plan update evaluates the risk of natural hazards prevalent in the OA and meets requirements of the Disaster Mitigation Act (44 CFR, Section 201.6(c)(2)).
To protect individual privacy and the security of critical facilities, information on properties assessed is presented in aggregate, without details about specific individual personal or public properties.
6.1 Identified Hazards of Concern
The Core Planning Group considered the full range of natural hazards that could affect the OA and then listed hazards that present the greatest concern. The process incorporated a review of state and local hazard planning documents as well as information on the frequency of, magnitude of, and costs associated with hazards that have struck the OA or could do so. Anecdotal information regarding natural hazards and the perceived vulnerability of the OA’s assets to them was also used. Based on the review, this plan addresses the following hazards of concern (presented in order of the hazard risk index results; the order of listing does not indicate the hazards’ relative severity):
Earthquake
Wildfire
Inclement Weather
Drought
Climate Change
Dam and Levee Failure
Flood
Landslide
Tsunami
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 6: Identified Hazards of Concern and Risk Assessment 71 In addition to the hazards of concern for which full risk assessments were performed, other hazards of interest were identified for inclusion in this plan: intentional hazards, technological hazards, and epidemic and pandemic. These hazards are of interest because they present risk to the OA. However, no methodologies are currently available to perform risk assessments on them that are equivalent to those used for the natural hazards of concern addressed in detail in this plan.
6.2 Hazard Risk Index
FEMA requires all hazard mitigation planning partners to have jurisdiction-specific mitigation actions based on local risk, vulnerability, and community priorities (FEMA, 2011). This plan included a risk index procedure for each planning partner, in which the degree of risk posed by each hazard was calculated based on a set of factors.
Risk index factors were assigned a numerical degree of risk level based on information presented in the hazard profiles and planning partner annexes. This number was then weighted, and a formula was used to aggregate the values into an overall hazard risk index number. The weight given to each factor was based on a review of best practices and agreed upon by the Core Planning Team.
All planning partners calculated risk for their own jurisdiction or special district following the same methodology. The higher the overall risk index number, the greater the hazard risk. This methodology does not compare hazards to each other or rank hazards against one another. Instead, this process provides a sense of hazard priorities or relative risk and allows comparison of the same hazard across participants. It provides planning participants with a sense of hazard priorities, or relative risk. By doing this analysis, mitigation planning and initiatives can focus on the greatest risk. While hazards occur together or as a consequence of others (e.g., dam failure may cause flooding and earthquakes may cause landslides), participants considered hazards as a singular event for the purposes of rating. This approach is part of a holistic hazard risk analysis that includes complementary qualitative and quantitative elements and provides a consistent metric across different hazards.
This hazard analysis methodology can:
Help establish priorities for planning, capability development, and hazard mitigation; Serve as a tool in the identification of hazard mitigation measures; Be one tool in conducting a hazard-based needs analysis; Serve to educate the public and public officials about hazards and vulnerabilities; and Help communities make objective judgments about acceptable risk.
The factors and their corresponding numeric indices and weight factors are detailed in Table 14.
Individual and OA-level hazard risk indices were used to inform the action plan development process and mitigation priorities for each planning partner. Each annex presents the risk indices for each planning partner.
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 6: Identified Hazards of Concern and Risk Assessment 72 Table 14: Probability of Hazards
Risk Index
Factor
Degree of Risk
Level Criteria
Factor
Weight for
Degree of
Risk Level
Probability of
Future Events
0 Unlikely
Less than 1 percent probability of occurrence
in the next year or a recurrence interval of
greater than every 100 years.
30%
1 Occasional
1 to 10 percent probability of occurrence in
the next year or a recurrence interval of 11 to
100 years.
2 Likely
11 to 90 percent probability of occurrence in
the next year or a recurrence interval of 1 to
10 years.
3 Highly Likely
91 to 100 percent probability of occurrence in
the next year or a recurrence interval of less
than 1 year.
Life Impact
0 Minor Very few injuries, if any at all.
35%
1 Limited Minor injuries.
2 Critical Multiple deaths and/or injuries.
3 Catastrophic High number of deaths and/or injuries.
Property Impact
0 Minor
Only minor property damage and minimal
disruption of life. Temporary shutdown of
critical facilities.
25%
1 Limited
More than 10 percent of property in affected
area damaged/destroyed. Complete
shutdown of critical facilities for more than
one day.
2 Critical
More than 25 percent of property in affected
area damaged/destroyed. Complete
shutdown of critical facilities for more than
one week.
3 Catastrophic
More than 50 percent of property in affected
area damaged/destroyed. Complete
shutdown of critical facilities for 30 days or
more.
Percentage of
Area Impacted
0 Negligible Less than 10 percent of planning area or
isolated single-point occurrences.
10%
1 Minimal 10 to 25 percent of the planning area or
limited single-point occurrences.
2 Significant 26 to 74 percent of planning area or frequent single-point occurrences.
3 Extensive 75 to 100 percent of planning area or
consistent single-point occurrences.
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 6: Identified Hazards of Concern and Risk Assessment 73 Table 15: Hazard Risk Ranking by Jurisdiction
Earthquake Wildfire Inclement
Weather Drought Climate Change
Dam and
Levee Failure Flood Landslide Tsunami
Campbell 2 0.9 1.7 0.7 0 1.75 0.55 0 0
Cupertino 2.7 1.9 1.1 1.45 1.55 0.45 0.5 0.4 0
Gilroy 2.9 1.05 1.25 0.9 0.3 2 0.4 0 0
Los Altos 2 1.95 2.05 1.8 1.6 0.95 0.65 0 0
Los Altos Hills 2 2.1 1.4 1.95 1.3 0 0.65 1.3 0
Los Gatos 1.45 2.55 1.15 0.6 1.2 0.35 0.35 0.65 0
Milpitas 2.3 2.05 0.9 1.2 2.3 1.85 1.8 0.6 0
Monte Sereno - - - - - - - - -
Morgan Hill 2.9 1.05 1.25 0.9 0.3 2 1.25 0 0
Mountain
View
2 0.65 1.4 2 1.3 0 2 0 0
Palo Alto 2 1.95 2.05 2.05 1.85 0.95 0.65 0 0
San Jose 1.25 1.6 1.8 1.45 0 1.9 1.9 0 0
Santa Clara
City
3 1.3 1.7 1.45 1.4 1.8 2 0 0.35
Saratoga 2.7 2 0.95 0.8 0.4 0 0 0.85 0
Sunnyvale 2.9 1.05 1.25 0.9 0.3 2 0.3 0 0
Santa Clara
County
2.1 1.7 1.55 0.8 1.6 1.75 0.65 0.4 0
SCC 2.1 1.7 1.55 0.8 1.6 1.75 0.65 0.4 0
MidPen 1.35 3 1.3 1.2 1.8 0.25 1.2 1.55 0
SCCFD 2.7 1.7 1.55 0.8 1.6 1.75 0.65 0.4 0
SCVWD - - - - - - - - -
Average 2.24 1.68 1.44 1.21 1.13 1.19 0.90 0.36 0.02
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 6: Identified Hazards of Concern and Risk Assessment 74
6.2.1 Average Overall Hazard Risk Index Results
The overall hazard risk index results based on an average of partner indices is shown in Table 16. These results show which hazards pose the highest overall risk to the Operational Area.
Table 16: Average Overall Hazard Risk Index Results
Hazard Risk Order Hazard Average Overall Hazard Risk
Index Result
1 Earthquake 2.24
2 Wildfire, smoke, and air quality 1.68
3 Inclement weather* 1.44
4 Drought 1.21
5 Climate change, including sea-level
rise
1.13 6 Dam and levee failure 1.19
7 Flood .90
8 Landslide and mass movement .36
9 Tsunami .02
*Listed as separate hazards in the hazard profile and annexes: heavy precipitation, high wind, extreme heat, extreme cold, and space weather.
Based on the average overall hazard risk index results from planning partner risk indices:
• The earthquake hazard has the highest risk results, followed by wildfire/smoke/air quality. The inclement weather, drought, climate change hazards were a moderate risk to the Operational Area.
The dam failure, flood, and landslide/mass movement hazards were a lower risk to the Operational Area.
The tsunami hazard poses the lowest risk to the Operational Area, as not all planning partners can be impacted by this hazard due to geographic location.
6.3 Risk Assessment Tools
6.3.1 Mapping
National, state, and county databases were reviewed to locate available spatially based data relevant to this planning effort. Maps were produced using geographic information system (GIS) software to show the spatial extent and location of hazards when such datasets were available. These maps are included in the hazard profile sections and planning partner annexes of this MJHMP.
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 6: Identified Hazards of Concern and Risk Assessment 75
6.3.2 Hazus
Overview
In 1997, FEMA developed the standardized Hazards U.S. (Hazus) model to estimate losses caused by earthquakes and identify areas that face the highest risk and potential for loss. Hazus was later expanded into a multi-hazard methodology with new models for estimating potential losses from hurricanes and floods.
Hazus is a GIS-based software program used to support risk assessments, mitigation planning, and emergency planning and response. It provides a wide range of inventory data, such as demographics, building stock, critical facility, transportation and utility lifeline, and multiple models to estimate potential losses from natural disasters. The program maps and displays hazard data and the results of damage and economic loss estimates for buildings and infrastructure. Its advantages include the following:
Provides a consistent methodology for assessing risk across geographic and political entities. Provides a way to save datasets so that they can readily be updated as population, inventory, and other factors change and as mitigation planning efforts evolve. Facilitates review of mitigation plans because it helps to ensure that FEMA methodologies are incorporated.
Supports grant applications by calculating benefits using FEMA definitions and terminology. Produces hazard data and loss estimates that can be used in communication with local stakeholders.
Is administered by the local government and can be used to manage and update a hazard mitigation plan throughout its implementation.
Levels of Detail for Evaluation
Hazus provides default data for inventory, vulnerability, and hazards; the default data can be supplemented with local data to provide a more refined analysis. The model can carry out three levels of analysis, depending on the format and level of detail of information about the OA:
Level 1: All of the information needed to produce an estimate of losses is included in the software’s default data. These data are derived from national databases and describe in general terms the characteristic parameters of the OA.
Level 2: More accurate estimates of losses require more detailed information about the OA. To produce Level 2 estimates of losses, detailed information is required about local geology, hydrology, hydraulics, and building inventory, as well as data about utilities and critical facilities.
This information is needed in a GIS format.
Level 3: This level of analysis generates the most accurate estimate of losses. It requires detailed engineering and geotechnical information to customize it for the OA.
6.4 Risk Assessment Approach
The risk assessments in this plan describe the risks associated with each identified hazard of concern.
The following steps were used to define the risk of each hazard:
Identify and profile each hazard: The following information is given for each hazard:
▪ Geographic areas most affected by the hazard.
▪ Event frequency estimates.
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 6: Identified Hazards of Concern and Risk Assessment 76 ▪ Severity estimates.
▪ Warning time likely to be available for response.
Define probability: probability of future events was identified utilizing the following terms:
▪ Unlikely – less than 1 percent probability of occurrence in the next year or a recurrence interval of greater than every 100 years.
▪ Occasional – 1 to 10 percent probability of occurrence in the next year or a recurrence interval of 11 to 100 years.
▪ Likely – 11 to 90 percent probability of occurrence in the next year or a recurrence interval of 1 to 10 years.
▪ Highly Likely – 91 to 100 percent probability of occurrence in the next year or a recurrence interval of less than 1 year.
Determine exposure to each hazard: Exposure was assessed by overlaying hazard maps with an inventory of structures, facilities, and systems to decide which of them would be exposed to each hazard.
Assess the vulnerability of exposed facilities: Vulnerability of exposed structures and infrastructure was evaluated by interpreting the probability of occurrence of each event and assessing structures, facilities, and systems that are exposed to each hazard. Tools such as GIS and Hazus were used for this assessment for the flood and earthquake hazards. Outputs similar to those from Hazus were generated for other hazards, using data generated through GIS.
6.4.1 Earthquake and Flood
The following hazards were evaluated using Hazus:
Flood: A Level 1 user-defined analysis was performed for general building stock in flood zones and for critical facilities and infrastructure. Digital Elevation Models (DEM) for the OA was used to delineate flood hazard areas and estimate potential losses from the 10-percent-annual-chance, 1- percent-annual-chance, and 0.2-percent-annual-chance flood events. To estimate damage that would result from a flood, Hazus uses pre-defined relationships between flood depth at a structure and resulting damage, with damage given as a percent of total replacement value.
Curves defining these relationships have been developed for damage to structures and for damage to typical contents within a structure. By inputting flood depth data and known property replacement cost values, dollar-value estimates of damage were generated. Earthquake: A Level 2 analysis was performed to assess earthquake exposure and vulnerability for three scenario events and two probabilistic events:
▪ A Magnitude-7.0 event on the Hayward Fault with an epicenter approximately 25 miles north of the City of Palo Alto.
▪ A Magnitude-7.0 event on the Calaveras Fault with an epicenter approximately 25 miles north of the City of Milpitas.
▪ A Magnitude-7.8 event on the San Andreas Fault with an epicenter approximately 148 miles northwest of the City of Palo Alto.
▪ The standard Hazus 100- and 500-year probabilistic events.
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 6: Identified Hazards of Concern and Risk Assessment 77
6.4.2 Drought
The risk assessment methodologies used for this plan focus on damage to structures. The risk assessment for drought was more limited and qualitative than the assessment for the other hazards of concern because drought does not affect structures.
6.4.3 All Other Assessed Hazards
Historical datasets were not adequate to model future losses for most of the hazards of concern.
However, areas and inventory susceptible to some of the hazards of concern were mapped by other means and exposure was evaluated. A qualitative analysis was conducted for other hazards using the best available data and professional judgment.
6.5 EMAP Consequence Analysis
A consequence analysis of the potential for detrimental impacts of hazards is included in this 2023 plan update for the Emergency Management Accreditation Program (EMAP). Each hazard identified in this plan is followed by the Consequence Analysis result.
In this analysis all nine natural hazards profiled for Santa Clara County have been addressed, with the impacts that each will have on the following:
Impact on the Public: What is the scope of impact on the health and safety of people in the area of the incident?
Impact on Responders: What is the scope of impact on health and safety of responders (i.e., firefighters, law enforcement, emergency management personnel, etc.) in the area responding to the incident?
Continuity of Operations: Will the organization need to relocate in order to fulfill duties? Will any other continuity measures be implemented?
Impact on Property, Facilities, and Infrastructure: What are potential damages to structures (private and public), utilities, treatment plants, electric grid, roads, and bridges? Delivery of Services: What impacts occur to the delivery of services such as food, medical, or any other life sustaining entities?
Impact on the Environment: How has the incident affected the surrounding environment, i.e., contamination (water, soil, or air), erosion, crop damage, etc.? Impact on the Economy: Are there any affects to the economy due to loss of revenue, cleanup efforts, and reconstruction?
Impact of the Public Confidence in the Jurisdiction’s Governance: How has the hazard affected public confidence?
The Consequence Analysis includes ranking determinations for each of the above elements. The ranking elements are categorized as Minimal, Moderate, or Severe. The Risk Assessment portion of the MJHMP was used to ascertain prior damages in an effort to estimate ratings on future impacts. The ratings are meant to be a guide, and not all inclusive, due to the variances that could apply such as population, location, time, hazard type, and the number of jurisdictions within the hazard area.
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 6: Identified Hazards of Concern and Risk Assessment 78
6.6 Sources of Data Used in Hazus Modeling
6.6.1 Building and Cost Data
Replacement cost values and detailed structure information and census data are included within Hazus
6.0. This recently updated version of Hazus uses 2020 census data and dasymetric census blocks for improved floodplain model accuracy. The stock building inventory data is from the National Structure Inventory (NSI), a point-based dataset developed by the U.S. Army Corps of Engineers (USACE). When available, updated data provided by Santa Clara County was used in place of the Hazus defaults for critical facilities and infrastructure.
Replacement cost is the cost to replace the entire structure with one of equal quality and utility.
Replacement cost is based on industry-standard cost-estimation models published in RSMeans Square Foot Costs.38F38 F
39 It is calculated using the RSMeans square foot cost for a structure, which is based on the Hazus occupancy class (i.e., multi-family residential or commercial retail trade), multiplied by the square footage of the structure from the tax assessor data. The construction class and number of stories for single-family residential structures also factor into determining the square foot costs.
6.6.2 Hazus Data Inputs
The following hazard datasets were used for the Hazus Level 2 analysis conducted for the risk assessment:
Flood: A USGS 10-meter Digital Elevation Model for the OA was used to delineate flood hazard areas and generate flood depth grids that are integrated into the Hazus model. These depth grids are used to estimate potential losses from the 10-percent-annual-chance, 1-percent-annualchance, and 0.2-percent-annual-chance flood events. Earthquake: Earthquake ShakeMaps and probabilistic data prepared by the USGS were used for the analysis of this hazard. A National Earthquake Hazard Reduction Program soils map from the California Department of Conservation, USGS liquefaction susceptibility data and susceptibility to deep-seated landslide from the California Geological Survey were also integrated into the Hazus model. Hazus uses classifications within these datasets to derive probabilities that ground deformation can occur in areas of higher liquefaction or landslide susceptibility. It should be noted that deep-seated landslides are generally large landslides that are slow moving during rainfall induced movement, but some can be fast moving and may occur during earthquakes. However, this dataset does not specifically measure earthquake induced landslides. Inclusion of liquefaction and landslide data in Hazus represent ground deformation that may occur during an earthquake that can contribute to structural damage. As such, inclusion of these datasets tends to increase the amount and cost of damage modeled by Hazus.
6.6.3 Other Local Hazard Data
Locally relevant information on hazards was gathered from a variety of sources. Frequency and severity indicators include past events and the expert opinions of geologists, emergency management specialists, and others. Data sources for specific hazards were as follows:
Landslide: Susceptibility to deep-seated landslide data were provided by the California Geological Survey.
39 RSMeans data from Gordian. (2023). Estimating Square Foot Cost. https://www.rsmeans.com/estimating-squarefoot-cost
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 6: Identified Hazards of Concern and Risk Assessment 79 Sea Level Rise: Sea level rise data were provided by the San Francisco Bay Conservation and Development Commission. A sea level rise of 6 feet above current mean higher high water was used for the exposure analysis.
Dam Inundation: Dam inundation exposure areas were acquired from the California Department of Water Resources Division of Safety of Dams. Many of these are owned by the Santa Clara Valley Water District.
Levee Inundation: Levee inundation exposure areas were defined with boundaries provided by Santa Clara County.
Severe Storm: No GIS format severe storm area datasets were identified for the OA. Tsunami: Tsunami inundation map was prepared by California Department of Conservation in cooperation with the University of Southern California, California Geological Survey, and California Emergency Management Agency.
Wildfire: Wildfire Hazard Classification and Structures at Risk data were provided by Tukman Geospatial. Additional fire severity data was acquired from California Department of Forestry and Fire Protection (CAL FIRE).
6.6.4 Data Source Summary
Table 17 summarizes the data sources used for the risk assessment for this plan.
Table 17: Hazus Model Data Documentation
Data Source Date Format
Building information such as area,
occupancy, date of construction,
and stories
FEMA Hazus version 6.0,
National Structure Inventory
(NSI), Santa Clara County
2023 Digital (tabular)
format
Building replacement cost FEMA Hazus version 6.0 2023 Digital (GIS and tabular) format
Population data FEMA Hazus version 6.0, US
Census Bureau
2020 Digital (GIS and
tabular) format
Flood hazard data FEMA 2016 Digital (GIS)
format
Tsunami CGS (State of California) 2021 Digital (GIS)
format
Earthquake ShakeMaps USGS, provided via Hazus
version 6.0
Downloaded
2023
Digital (GIS)
format
Liquefaction susceptibility USGS (via ABAG) 2006 Digital (GIS) format
National Earthquake Hazard
Reduction Program
California Department of
Conservation, California
Geological Survey
Downloaded
2023
Digital (GIS)
format
Dam Inundation Areas California Department of
Water Resources, Division of
Safety of Dams
Varies
2019-2021
Digital (GIS)
format
Landslide California Geological Survey 2011 Digital (GIS) format
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 6: Identified Hazards of Concern and Risk Assessment 80 Data Source Date Format
Sea Level Rise Adapting to Rising Tides -
San Francisco Conservation
and Development
Commission
2018 Digital (GIS)
format
Wildfire Tukman Geospatial, CAL
FIRE
2022, 2007 Digital (GIS)
format
Digital Elevation Model USGS Downloaded
2023
Digital (GIS)
format
Critical Facilities and Assets Hazus version 6.0, Santa Clara County
2023 Digital (GIS)
format
Emergency operation centers,
airport facilities, bus facilities, light
rail facilities, rail facilities,
communication facilities, electric
power facilities, potable water
facilities, wastewater facilities
FEMA Hazus version 6.0
Default Critical Facilities Data
2023 Digital (GIS)
format
Points of interest (city halls,
community centers, other county
facilities, child day care facilities)
Santa Clara County 2023 Digital (GIS)
format
Santa Clara County critical facilities
(fire stations, hospitals, skilled
nursing facilities and clinics, police
stations, public / private schools,
universities, and colleges)
FEMA Hazus version 6.0,
Santa Clara County
2023 Digital
(spreadsheet)
format
Superfund sites (hazardous material
sites)
EPA 2022 Digital (GIS)
format
Toxic release inventory facilities
(hazardous material facilities,
designated communications
centers, electric power, and
petroleum facilities)
Environmental Protection
Agency (EPA)
Downloaded
2023
Digital (GIS)
format
State and local bridges (highway
bridges, light rail bridges, rail
bridges, includes pedestrian
bridges)
Hazus 6.0 Inventory, Santa
Clara County
2023 Digital (GIS)
format
6.7 Limitations
Loss estimates, exposure assessments, and hazard-specific vulnerability evaluations rely on the best available data and methodologies. Uncertainties are inherent in any loss estimation methodology and arise in part from incomplete scientific knowledge concerning natural hazards and their effects on the built environment. Uncertainties also result from the following:
Approximations and simplifications necessary to conduct a study. Incomplete or outdated inventory, demographic or economic parameter data. The unique nature, geographic extent, and severity of each hazard. Mitigation measures already employed.
Santa Clara County Multijurisdictional Hazard Mitigation Plan Section 6: Identified Hazards of Concern and Risk Assessment 81 The amount of advance notice residents have to prepare for a specific hazard event. Lack of a standardized model for assessing sea level rise impacts. Multiple models provide multiple results. Not all models were run in the development of the sea level rise analysis.
These factors can affect loss estimates by a factor of two or more. Therefore, potential exposure and loss estimates are approximate and should be used only to understand relative risk. Over the long term, Santa Clara County will collect additional data to assist in estimating potential losses associated with other hazards.
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7 Earthquake
Definitions
Earthquake: The shaking of the ground caused by an abrupt shift of rock along a fracture in the earth or a contact zone between tectonic plates.
Epicenter: The point on the earth’s surface directly above the hypocenter of an earthquake. The location of an earthquake is commonly described by the geographic position of its epicenter and by its focal depth.
Fault: A fracture in the earth’s crust along which two blocks of the crust have slipped with respect to each other.
Hypocenter: The region underground where an earthquake’s energy originates. Liquefaction: Loosely packed, water-logged sediments losing their strength in response to strong shaking, causing major damage during earthquakes.
7.1 General Background
An earthquake is the vibration of the earth’s surface following a release of energy in the earth’s crust. This energy can be generated by a sudden dislocation of the crust or by a volcanic eruption. Most destructive quakes are caused by dislocations of the crust. The crust may first bend and then, when the stress exceeds the strength of the rocks, break and snap to a new position. In the process of breaking, vibrations called “seismic waves” are generated. These waves travel outward from the source of the earthquake at varying speeds.
Geologists have found that earthquakes tend to reoccur along faults, which are zones of weakness in the earth’s crust. Even if a fault zone has recently experienced an earthquake, there is no guarantee that all the stress has been relieved. Another earthquake could still occur. In fact, relieving stress can increase stress in other parts of the affected fault and other faults. Additional earthquakes, called aftershocks, are common after a large earthquake.
California is seismically active because of movement of the North American Plate, east of the San Andreas Fault, and the Pacific Plate to the west, which includes the state’s coastal communities.
Movement of the tectonic plates against one another creates stress, which is released as energy that moves through the earth as seismic waves.
Faults are classified in terms of their activity level; “active,” “potentially active,” or “inactive.” Most seismic activity occurs along faults that are known to have geologic evidence of activity. However, inactive faults, where no such displacements have been recorded, also have the potential to reactivate or experience displacement along a branch sometime in the future. An example of a fault zone that has been reactivated is the Foothills Fault Zone. The zone was considered inactive until evidence of an earthquake (approximately 1.6 million years ago) was found near Spenceville, California. Then, in 1975, an earthquake occurred on another branch of the zone near Oroville, California (now known as the Cleveland Hills Fault). The State Division of Mines and Geology indicates that increased earthquake activity throughout California may cause tectonic movement along currently inactive fault systems.
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7.1.1 Damage from Earthquakes
A direct relationship exists between a fault’s length and location and its ability to generate damaging ground motion at a given site. Small, local faults produce lower magnitude quakes, but ground shaking can still be strong, and damage can be significant in areas close to the fault. In contrast, large regional faults can generate earthquakes of great magnitudes but, because of their distance and depth, they may result in only moderate shaking in an area.
Earthquakes can last from a few seconds to over five minutes; they may also occur as a series of tremors over a period of several days. Aftershocks may be felt for months or years after the mainshock. The actual movement of the ground in an earthquake is seldom the direct cause of injury or death. People that fall over during the quake may experience more mild injuries like broken bones. Casualties generally result from falling objects and debris, because earthquakes shake, damage, or demolish furnishings and buildings and other structures. Disruption of communications and internet, electrical power, gas, sewer, and water services should be expected in the affected area. Earthquakes may trigger dam failures and landslides. Their damage may cause fires and releases of hazardous material, compounding the disastrous effects.
7.1.2 Earthquake Classifications
Earthquakes are typically classified in one of two ways: by the amount of energy released, measured as magnitude; or by the impact on people and structures, measured as intensity.
Magnitude
An earthquake’s magnitude is a measure of the energy released at the source of the earthquake. It is commonly expressed by ratings on either of two scales (Michigan Tech University)39F39F 40:
The Richter scale measures magnitude of earthquakes based on the amplitude of the largest energy wave released by the earthquake. Richter scale readings are suitable for smaller earthquakes; however, because it is a logarithmic scale, the scale does not distinguish clearly the magnitude of large earthquakes above a certain level. Richter scale magnitudes and corresponding earthquake effects are as follows:
▪ 2.5 or less: Usually not felt, but can be recorded by seismograph. ▪ 2.5 to 5.4: Often felt, but causes only minor damage. ▪ 5.5 to 6.0: Slight damage to buildings and other structures. ▪ 6.1 to 6.9: May cause a lot of damage in very populated areas. ▪ 7.0 to 7.9: Major earthquake; serious damage.
▪ 8.0 or greater: Great earthquake; can totally destroy communities near the epicenter. 40 Michigan Tech University. (n.d.) How do we measure Earthquake Magnitude? https://www.mtu.edu/geo/community/seismology/learn/earthquake-measure/
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While the Richter scale may be well known, the most commonly used scale today is the moment magnitude (Mw) scale. The moment magnitude scale is based on the total moment release of the earthquake (the product of the distance a fault moved, and the force required to move it).
Moment magnitude roughly matches the Richter scale but provides more accuracy for larger magnitude earthquakes. The scale is as follows:
▪ Great: Mw > 8.
▪ Major: Mw = 7.0 - 7.9.
▪ Strong: Mw = 6.0 - 6.9.
▪ Moderate: Mw = 5.0 - 5.9.
▪ Light: Mw = 4.0 - 4.9.
▪ Minor: Mw = 3.0 - 3.9.
▪ Micro: Mw < 3.
Intensity
For an earthquake, intensity varies across the area. Intensity will be larger near the fault rupture, in the direction of the rupture, and in sedimentary basins. Sedimentary basins are depressions in the earth’s surface that consist of alluvial deposit and sedimentary rocks, which are geologically younger and have slower seismic wave velocities.40F40F
41 Sedimentary basins like the Evergreen basin, which lies beneath the northeastern margin of the Santa Clara Valley near the south end of the San Francisco Bay, amplify the ground shaking during an earthquake, increasing the intensity of the quake. Currently the most commonly used intensity scale is the Modified Mercalli Intensity (MMI) Scale, with ratings defined in Figure 19.41F41 F 42 41 U.S. Geological Survey. (2020). Earthquake Science Center Seminars, Sedimentary basin effects in ground motions from empirical models and simulation platforms. https://earthquake.usgs.gov/contactus/menlo/seminars/1297#:~:text=Sedimentary%20basins%20are%20depressions %20in,in%20thickness%20towards%20their%20margins.
42 U.S. Geological Survey. (n.d.). The Modified Mercalli Intensity (MMI) Scale assigns intensities as…. https://www.usgs.gov/media/images/modified-mercalli-intensity-mmi-scale-assigns-intensities
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Figure 20: Modified Mercalli Intensity Scale42F42F
43 7.1.3 Ground Motion
Earthquake hazard assessment is also based on expected ground motions. During an earthquake when the ground is shaking, it experiences acceleration. The peak ground acceleration (PGA) is the largest increase in velocity recorded by a particular station during an earthquake. PGA indicates the severity of an earthquake and is a measure of how hard the earth shakes, or accelerates, in a given geographic area. It is measured in g (the acceleration due to gravity), expressed as a percentage of that acceleration (%g). Horizontal and vertical PGA varies with soil or rock type. Instruments called accelerographs record levels of ground motion due to earthquakes at stations throughout a region. These readings are recorded by state and federal agencies that monitor and predict seismic activity. Earthquake hazard assessment involves estimating the annual probability that certain ground motion accelerations will be exceeded, and then summing the annual probabilities over the time period of interest.
National maps of earthquake shaking hazards, which have been produced since 1948, provide information for creating and updating seismic design requirements for building codes, insurance rate structures, earthquake loss studies, retrofit priorities and land use planning. After thorough review of the studies, professional organizations of engineers update the seismic-risk maps and seismic design requirements contained in building codes, the USGS updated the National Seismic Hazard Maps in 2018. 43 U.S. Geological Survey. (n.d.). The Modified Mercalli Intensity (MMI) Scale Assigns Intensities as... https://www.usgs.gov/media/images/modified-mercalli-intensity-mmi-scale-assigns-intensities
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New seismic, geologic, and geodetic information on earthquake motion, soil amplification factors, and local seismic velocity models was incorporated into the revised maps, allowing the USGS, for the first time, to calculate probabilistic seismic hazard curves for an expanded time period and site classes as well as account for long-period ground motions in deep sedimentary basins like the San Francisco Bay region.43F43F
44 The USGS is currently working on updating this model with a targeted release later in 2023.
These maps influence earthquake insurance rates and support government official, emergency managers, community planners, and the public in understanding the potential risks to their community.
Building codes that include seismic provisions specify the horizontal force due to lateral acceleration that a building should be able to withstand during an earthquake. Buildings, bridges, highways, and utilities built to meet modern seismic design requirements are typically able to withstand earthquakes better, with less damage and disruption. PGA values are directly related to these lateral forces that could damage “short period structures” (e.g., single-family dwellings). Longer-period response components determine the lateral forces that damage taller structures with longer natural periods (apartment buildings, factories, high-rises, bridges). Figure 20 lists damage potential and perceived shaking by PGA factors, compared to the Mercalli scale.
Figure 21: Peak Acceleration (%g) with 10% Probability of Exceedance in 50 Years4F4 F 45 44 U.S. Geological Survey. (2021, September 23). Data Release for Additional Period and Site Class Data for the 2018 National Seismic Hazard Model for the Conterminous United States. https://www.usgs.gov/data/data-releaseadditional-period-and-site-class-data-2018-national-seismic-hazard-model 45 U.S. Geological Survey. (2018). 2018 Long-term National Seismic Hazard Map. https://www.usgs.gov/media/images/2018-long-term-national-seismic-hazard-map
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Table 18: Mercalli Scale and Peak Ground Acceleration Comparison45F45 F 46 Modified
Mercalli
Scale
Perceived
Shaking
Potential Structure Damage
Estimated PGAa
Resistant (%g)
Buildings
Vulnerable
Buildings
I Not Felt None None <0.17%
II-III Weak None None 0.17% - 1.4%
IV Light None None 1.4% - 3.9%
V Moderate Very Light Light 3.9% - 9.2%
VI Strong Light Moderate 9.2% - 18%
VII Very Strong Moderate Moderate/Heavy 18% - 34%
VIII Severe Moderate/Heavy Heavy 34% - 65%
IX Violent Heavy Very Heavy 65% - 124%
X - XII Extreme Very Heavy Very Heavy >124%
a PGA measured in percent of g, where g is the acceleration of gravity.
7.1.4 Effect of Soil Types
The impact of an earthquake on structures and infrastructure is largely a function of ground shaking, distance from the source of the quake, and liquefaction, a secondary effect of an earthquake in which soils lose their shear strength and flow or behave as liquid, thereby damaging structures that derive their support from the soil. Liquefaction generally occurs in soft, unconsolidated sedimentary soils and shallow water table.
A program called the National Earthquake Hazard Reduction Program (NEHRP) creates maps based on soil characteristics to help identify locations subject to liquefaction. Table 19 summarizes NEHRP soil classifications. NEHRP Soils B and C typically can sustain ground shaking without much effect, dependent on the earthquake magnitude. The areas that are commonly most affected by ground shaking have NEHRP Soils D, E, and F. In general, these areas are also most susceptible to liquefaction.
Table 19: National Earthquake Hazard Reduction Program Soil Classification System46F46F 47 NEHRP Soil Type Description
Mean Shear
Velocity to 30 m
(m/s)
A Hard Rock 1,500
B Firm to Hard Rock 760–1,500
C Dense Soil/Soft Rock 360–760
D Stiff Soil 180–360
E Soft Clays < 180
46 SanAndreasFault.org. (2010). Did you feel it? http://www.sanandreasfault.org/feelit.html 47 National Earthquake Hazard Reduction Program. (n.d.). Seismic Site Classification. https://www.masw.com/files/NEHRP.pdf
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NEHRP Soil Type Description
Mean Shear
Velocity to 30 m
(m/s)
F Special Study Soils (liquefiable soils, sensitive clays, organic soils, soft clays >36 m thick)
The USGS has created a soil type map for the San Francisco Bay area that provides rough estimates of site effects based on surface geology. NEHRP soil types were assigned to a geologic unit based on the average velocity of that unit, and the USGS notes that this approach can lead to some inaccuracy. For instance, a widespread unit consisting of Quaternary sand, gravel, silt, and mud has been assigned as Class C soil types; however, some of the slower soil types in this unit fall under Class D. USGS does not have any way of differentiating units for slower-velocity soils in its digital geologic dataset.47F47F 48 7.2 Hazard Profile
The Bay region is located within the active boundary between the Pacific and the North American tectonic plates. The western edge of the Santa Clara County OA is on the Pacific Plate, which is constantly moving northwest past the North American Plate at a rate of about 2 inches per year.48F48F 49 Earthquakes in
the San Francisco Bay region result from strain energy constantly accumulating across the region because of the motion of the Pacific Plate relative to the North American Plate. The San Andreas Fault, on which earthquakes of magnitude 7.8 and 7.9 have occurred in historical time, including the 1906 San Francisco earthquake, is the fastest slipping fault along the plate boundary.
7.2.1 Past Events
The last major earthquake with an epicenter in the Santa Clara County OA was the 1984 Morgan Hill Earthquake (Magnitude 6.2). The epicenter of the 1989 Loma Prieta Earthquake (Magnitude 7.1) was just a few miles outside the OA. Since then, there have been no significant seismic events in Santa Clara County.49F49 F
50 Other significant earthquakes in California include the 1906 earthquake in San Francisco, the 1971 San Fernando Earthquake, the 1994 Northridge earthquake, the 2014 Napa earthquake, and the 2019 Ridgecrest earthquake.
The Morgan Hill Earthquake of April 24, 1984, was a moderate size earthquake on the Calaveras Fault. It caused moderate damage that extended southward from the epicenter. In the Santa Clara County OA, where most of the damage occurred, more than 550 structures experienced minor damage. Major structural damage was mostly confined to a small area on two streets in the Jackson Oaks subdivision east of Morgan Hill. There were numerous reports of fires resulting from the earthquake. Minor damage was also reported in San Martin and Coyote. Twenty-seven people were injured.50 F50F 51 This event led to a
FEMA major disaster declaration (DR-845).
48 U.S. Geological Survey. (2006). Geologic Map of the San Francisco Bay Region. https://pubs.usgs.gov/sim/2006/2918/sim2918_geolposter-stdres.pdf 49 U.S. Geological Survey. (n.d.). Earthquake Facts & Earthquake Fantasy. https://www.usgs.gov/programs/earthquake-hazards/earthquake-facts-earthquakefantasy#:~:text=The%20Pacific%20Plate%20moves%20northwestward%20past%20the%20North,tiny%20shocks%2 0and%20a%20few%20moderate%20earth%20tremors.
50 Association of Bay Area Governments. (n.d.). Resilience. https://abag.ca.gov/our-work/resilience 51 Association of Bay Area Governments. (2011). Bay Area Local Hazard Mitigation Plan Taming Natural Hazards. https://abag.ca.gov/2011-bay-area-hazard-mitigation-plan
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The Loma Prieta Earthquake on October 17, 1989, occurred near Loma Prieta in the Santa Cruz Mountains along the San Andreas Fault. Thousands of landslides across the area blocked roads and highways, impacting rescue efforts and damaging structures. In Santa Clara County, collapsed and damaged buildings were reported in Gilroy, Los Gatos, and San José.51F51 F 52 California has been included in 13 FEMA major disaster (DR) or emergency (EM) declarations for earthquakes. Santa Clara County was included in only one declaration: DR-845 for the Loma Prieta Earthquake, which occurred in 1989. The declaration for this event covered Alameda, Contra Costa, Marin, Monterey, Sacramento. Table 20 and Figure 21 summarize recent earthquakes of magnitude of
5.0 or greater within a 100-mile radius of the OA.
Table 20: Recent Earthquakes Magnitude 5.0 or Larger Within a 100-Mile Radius of the Operational Area
Date Magnitude Epicenter Location
10/25/2022 5.1 9 miles east-southeast of Alum Rock, California 4/5/2018 5.3 19 miles southwest of Santa Cruz, California 8/24/2014 6.0 South Napa, California
10/21/2012 5.3 15 miles east-northeast of King City, California 10/31/2007 5.5 San José, California
5/14/2002 5.0 Northern California
9/3/2000 5.0 Northern California
8/12/1998 5.2 Central California
4/18/1990 5.4 Northern California
10/17/1989 6.9 Loma Prieta, California Earthquake
10/18/1989 5.1 4 miles southwest of Monte Sereno, California 8/8/1989 5.4 Northern California
6/27/1989 5.3 Northern California
6/13/1988 5.3 San Francisco Bay Area, California
2/20/1988 5.1 Central California
3/31/1986 5.7 Northern California
1/26/1986 5.4 Central California
52 Association of Bay Area Governments. (2011). Bay Area Local Hazard Mitigation Plan Taming Natural Hazards. https://abag.ca.gov/2011-bay-area-hazard-mitigation-plan
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Figure 22: Historic Earthquakes in the Operational Area
7.2.2 Location
Santa Clara County is exposed to three major regional faults: Hayward, Calaveras, and San Andreas.
The Hayward and Calaveras faults are in the central portion of Santa Clara County and present the greatest earthquake threat to the OA. The San Andreas Fault is on the northwestern boundary of the OA and runs through hills separating Santa Clara County from Santa Cruz County. The primary seismic hazard for the OA is potential ground shaking from these three large faults.52F52 F 53 The Greenville fault in the
northeastern portion of the county presents less risk than these three major faults. Figure 22 provides 53 Association of Bay Area Governments. (n.d.). Earthquake. https://abag.ca.gov/our-work/resilience/dataresearch/earthquake
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location and probability of area fault lines. The three major faults are described further in the following sections.
Hayward Fault
The Hayward Fault runs parallel to and east of the San Andreas Fault. It extends from San José about 74 miles northward along the base of the East Bay Hills to San Pablo Bay. The fault is a right-lateral slip fault. The Hayward Fault extends through some of the Bay Area’s most populated areas. Communities on or near the fault include San José, Oakland, Fremont, Richmond, Berkeley, Hayward, San Leandro, San Lorenzo, El Cerrito, Emeryville, Kensington, and Milpitas. Among other sites, the fault runs directly under the now-abandoned old city hall in downtown Hayward, the University of California-Berkeley football stadium, the Mira Vista Golf Course near Berkeley, Lake Temescal, Contra Costa College, and Port Pinole Shoreline Regional Park. It is the single most urbanized earthquake fault in the United States.53F53 F 54 The Hayward Fault is becoming a hazard priority throughout the Bay Area because of its increased chance for activity and its intersection with multiple highly populated areas and critical infrastructure.
According to the Uniform California Earthquake Rupture Forecast, Volume 3, released in March 2015, the probability of experiencing a Magnitude 6.7 or greater earthquake along the Hayward Fault in the next 30 years (starting from 2014) is 14.3 percent.54 F54F
55 An earthquake of this magnitude has regional implications for the entire Bay Area, as the Hayward Fault crosses transportation and resource infrastructure, including multiple highways, regional gas and water pipelines, electrical transmission lines, and the Hetch-Hetchy Aqueduct. Disruption of the Hetch-Hetchy system has the potential to severely impair water service to the Santa Clara County OA.
An important difference between the Hayward and San Andreas faults is “aseismic creep.” The San Andreas Fault is locked in many places; much of its energy is released in the form of earthquakes.
However, creep occurs in spots along the Hayward Fault. The ground moves a few millimeters each year, pulling apart sidewalks, pipelines and other structures that sit astride the fault. At Memorial Stadium at the University of California Berkeley, which was built in 1923, creep has caused the two sides of the stadium to be offset more than a foot, requiring retrofitting with expansion joints. Creep accounts for a small part of the total motion that takes place on a fault over geologic time; earthquakes account for the rest.5F5F 56 54 California Office of Emergency Services. (2016, July 6). Bay Area Earthquake Plan. https://www.caloes.ca.gov/wpcontent/uploads/Preparedness/Documents/BayAreaEQConopsPub_Version_2016.pdf. 55 U.S. Geological Survey. (2015, March). UCEFR3: A New Earthquake Forecast for California’s Complex Fault System. https://pubs.usgs.gov/fs/2015/3009/pdf/fs2015-3009.pdf 56 California Department of Conservation. (2008, October 7). Hayward Fault Fact Sheet. https://www.conservation.ca.gov/index/Pages/HaywardFaultFactSheet.aspx
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Figure 23: Significant Known Faults in the Bay Area56F
57 57 U.S. Geological Survey. (2016, August). Earthquake Outlook for the San Francisco Bay Region 2014-2043. https://pubs.usgs.gov/fs/2016/3020/fs20163020.pdf
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Calaveras Fault
The Calaveras Fault is a major branch of the San Andreas Fault, located to the east of the Hayward Fault. It extends 76 miles from the San Andreas Fault near Hollister to Danville at its northern end. The Calaveras Fault is one of the most geologically active and complex faults in the Bay Area. Recent research from the University of Berkeley suggests that the Hayward fault is essentially an offshoot of the Calaveras Fault.57F
58 This means that they could go off together, potentially creating a larger event as an earthquake’s magnitude is relative to its length. In a worst case scenario, a rupture along the Hayward fault could extend to the Calaveras Fault and south to where the Calaveras Fault meets the San Andreas Fault. The probability of experiencing a Magnitude 6.7 or greater earthquake along the Calaveras Fault in the next 30 years is 7.4% percent.
San Andreas Fault
The San Andreas Fault extends 810 miles from the East Pacific rise in the Gulf of California through the Mendocino fracture zone off the shore of northern California. The fault is estimated to be 28 million years old. The San Andreas Fault is an example of a transform boundary exposed on a continent. It forms the tectonic boundary between the Pacific Plate and the North American Plate, and its motion is right-lateral strike-slip.
The San Andreas Fault is typically referenced in three segments. The southern segment extends from its origin at the East Pacific Rise to Parkfield, California, in Monterey County. The central segment extends from Parkfield to Hollister, California. The northern segment extends northwest from Hollister, through Santa Clara County, to its ultimate junction with the Mendocino fracture zone and the Cascadia subduction zone in the Pacific Ocean. The probability of experiencing a Magnitude 6.7 or greater earthquake along the San Andreas Fault within the next 30 years is 6.4 percent.
Maps of Earthquake Impact on the OA
The impact of an earthquake is largely a function of the following components:
Surface fault rupture
Ground shaking (ground motion accelerations)
Liquefaction (soil instability)
Impacts vary with distance from the source (both horizontally and vertically). Mapping that shows the impacts of these components was used to assess the risk of earthquakes within the OA, as described in the sections below.
Probabilistic Seismic Hazard Map
A probabilistic seismic hazard map shows the hazard from earthquakes that geologists and seismologists agree could occur. The maps are expressed in terms of probability of exceeding a certain ground motion, such as the 10-percent probability of exceedance in 50 years. This level of ground shaking has been used for designing buildings in high seismic areas.58F
59 58 University of California Berkley. (2015, April 2). https://news.berkeley.edu/2015/04/02/calaveras-hayward-fault-linkmeans-potentially-larger-quakes/ 59 Probabilistic Seismic Hazard Assessment, Association of Bay Area Government Resilience Program (2018, February 22) https://www.arcgis.com/home/item.html?id=c3a21989363b484ca6f9c0730e14d9f6.
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Figure 24: 500-Year Probabilistic Earthquake Scenario Peak Ground Acceleration
7.2.3 ShakeMaps
A ShakeMap is a representation of ground shaking produced by an earthquake. The information it presents is different from the earthquake magnitude and epicenter that are released after an earthquake because ShakeMaps focus on the ground shaking resulting from the earthquake, rather than the parameters describing the earthquake source. An earthquake has only one magnitude and one epicenter, but it produces a range of ground shaking at sites throughout the region, depending on the distance from the earthquake, the rock and soil conditions at sites, and variations in the propagation of seismic waves from the earthquake due to complexities in the structure of the earth’s crust. A ShakeMap shows the extent and variation of ground shaking in a region immediately following significant earthquakes.
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Ground motion and intensity maps are derived from peak ground motion amplitudes recorded on seismic sensors (accelerometers), with interpolation based on estimated amplitudes where data are lacking, and site amplification corrections. Color-coded instrumental intensity maps are derived from empirical relations between peak ground motions and Modified Mercalli intensity.
There are two types of scenario ground motion maps: a ShakeMap of median shaking for a fault rupture; and a map of simulated ground motions for a specified earthquake hypocenter and fault rupture. The latter is more like an earthquake event and presents more variability in ground motions than a scenario ShakeMap.
Earthquake scenario maps describe the expected ground motions and effects of hypothetical large earthquakes for a region. The following scenarios were chosen for this plan:
• A Magnitude 7.0 on the Hayward Fault with an epicenter approximately 25 miles north of the City of Palo Alto. 59F
60 • A Magnitude 7.0 on the Calaveras Fault with an epicenter approximately 25 miles north of the City of Milpitas. 60F
61 • A Magnitude 7.8 on the San Andreas Fault with an epicenter approximately 148 miles northwest of the City of Palo Alto. 61F
62 60 U.S. Geological Survey Shakemap Scenario. (n.d.) M 7.0 Scenario Earthquake – Hayward – Rodgers Creek. https://earthquake.usgs.gov/scenarios/eventpage/nclegacyhaywardrodgerscreekhnhsm7p0_se/executive. 61 U.S. Geological Survey Shakemap Scenario (n.d.) M 7.0 Scenario Earthquake – Calaveras North + Central+ South. https://earthquake.usgs.gov/scenarios/eventpage/nclegacycalaverascncccsm7p0_se/executive. 62 USGS Shakemap Scenario (n.d.) M 7.8 Scenario Earthquake – N. San Andreas; North Coast + Peninsula + Santa Cruz Mountain.
https://earthquake.usgs.gov/scenarios/eventpage/nclegacynpsanandreassansapsasm7p8_se/executive.
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Figure 25: Hayward Magnitude 7.0 Fault Scenario Peak Ground Acceleration
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Figure 26: Calaveras Magnitude 7.0 Fault Scenario Peak Ground Acceleration
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Figure 27: San Andreas Magnitude 7.8 Fault Scenario Peak Ground Acceleration Liquefaction Maps
Soil liquefaction maps are useful tools to assess potential damage from earthquakes. When the ground liquefies, sandy or silty materials saturated with water behave like a liquid, causing pipes to leak, roads and airport runways to buckle, and building foundations to be damaged. In general, areas with NEHRP Soils D, E, and F are also susceptible to liquefaction. If there is a dry soil crust, excess water will sometimes come to the surface through cracks in the confining layer, bringing liquefied sand with it, creating sand boils. Figure 27 shows the liquefaction susceptibility in the Santa Clara County OA.
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Figure 28: Liquefaction Susceptibility
Alquist-Priolo Zone Maps
The sliding movement of earth on either side of a fault is called fault rupture. Fault rupture begins below the ground surface at the earthquake hypocenter, typically between 3 and 12 miles below the ground surface in California. If an earthquake is large enough, the fault rupture will travel to the ground surface, potentially destroying structures built across its path.
California’s Alquist-Priolo Zone maps define regulatory zones for potential surface fault rupture where fault lines intersect with future development and populated areas. The purpose of these maps is to assist in the geologic investigation before construction begins to ensure that structures will not be located on an active fault.
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Cities and counties affected by the zones must regulate certain development projects while sellers of real estate must disclose at the time of sale that the property lies within such a zone. The Santa Clara County OA is located in a designated Alquist-Priolo Zone for the Hayward Fault.62 F 63 Alquist-Priolo maps were referenced, but not specifically used, in the assessment of risk for this plan. This plan assumes that the studies conducted and information provided by the State of California are the best available data for surface rupture risk and could not be improved through a separate assessment for this plan. Alquist-Priolo maps are available to the public on the California Department of Conservation website.63F
64 7.2.4 Frequency
California experiences hundreds of earthquakes each year, most with minimal damage and magnitudes below 3.0 on the Richter Scale. Earthquakes that cause moderate damage to structures occur several times a year. According to the USGS, a strong earthquake measuring greater than 5.0 on the Richter Scale occurs every 2 to 3 years and major earthquakes of more than 7.0 on the Richter Scale occur once a decade.
The USGS estimated in 2016 that there is a 72-percent probability of at least one earthquake before 2043 with a magnitude of 6.7 or greater that could cause widespread damage in the San Francisco Bay area.64F 65 According to the Third Uniform California Earthquake Rupture Forecast, the probability of moderate-sized earthquakes (magnitude 6.5 to 7.5) is lower than previously forecasted, whereas that of larger events is higher.65F
66 This is because the new study took into account the possibility of ruptures along multiple faults simultaneously. Probabilities for earthquakes on major fault lines in the San Francisco Bay Area have been estimated by the USGS in its 2016 report, as summarized in Table 21.
A major earthquake could happen at any time. Both the San Andreas and the Hayward Faults have the potential for experiencing major to great events. Large earthquakes along the Hayward Fault have occurred on average every 150 years – the last being in 1868.6F 67 USGS describe the fault as a “tectonic
time bomb.”.67F
68 Any seismic activity of 6.0 or greater on faults within the OA would have significant impacts throughout the OA. Bay Area communities can use the likelihood of a 6.8-7.0 earthquake near San Francisco as a predictive model of what to prepare for.
Further information on the impact of climate change on the probability of earthquakes is included in Section 11.
Probability in OA: Likely
63 California Department of Conservation. (2008). Hayward Fault Fact Sheet. https://www.conservation.ca.gov/index/Pages/HaywardFaultFactSheet.aspx 64 California Department of Conservation. (2023). The California Seismic Hazards Program. https://www.conservation.ca.gov/cgs/sh
65 U.S. Geological Survey. (2016, August). Earthquake Outlook for the San Francisco Bay Region 2014-2043. https://pubs.usgs.gov/fs/2016/3020/fs20163020.pdf
66 Southern California Earthquake Center. (2017). Third Uniform California Earthquake Rupture Forecast. https://www.scec.org/ucerf#:~:text=UCERF3%20shows%20the%20likelihood%20of%20moderatesized%20earthquakes%20%28magnitude,may%20occasional%20rupture%20together%20to%20cause%20larger%2 0earthquakes.
67 California Earthquake Authority. (2020, July 8). What to Expect from an Earthquake along the Hayward Fault. https://www.earthquakeauthority.com/Blog/2019/hayward-fault-earthquake-prediction 68 U.S. Geological Survey. (2008). The Hayward Fault – Is it Due for a Repeat of the Powerful 1868 Earthquake? https://pubs.usgs.gov/fs/2008/3019/
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Table 21: Earthquake Probabilities for the San Francisco Bay Area Region, 2014–204368F 69 Fault Probability of One or More M ≥ 6.7 Quake
2014–2043
Hunting Creek 16%
Green Valley 16%
Concord 16%
Greenville 16%
Berryessa 16%
Calaveras 26%
Maacama 8%
Rodgers Creek Fault 33%
Hayward 33%
San Andreas 22%
San Gregorio 6%
7.2.5 Severity
The severity of an earthquake can be expressed in terms of intensity or magnitude:
Intensity represents the observed effects of ground shaking at any specified location. The intensity of earthquake shaking lessens with distance from the earthquake epicenter. Tabulated peak ground accelerations for listed “maximum credible earthquakes” are a measure of how a site will be affected by seismic events on distant faults. Magnitude represents the amount of seismic energy released at the hypocenter of the earthquake. It is based on the amplitude of the earthquake waves recorded on instruments.
Magnitude is thus represented by a single, instrumentally determined value. 69 U.S. Geological Survey. (2017). Map of Known Active Faults and Earthquake Probabilities. https://www.usgs.gov/media/images/map-known-active-faults-and-earthquake-probabilities