HOW TO USE THIS PLAN FEMA has defined very specific requirements for Local Hazard Mitigation Plans and this plan follows those guidelines. The organization of the Plan follows FEMA’s structural requirements and includes the four following organizational levels: Parts Chapters Sections Subsections This LHMP is organized into five primary parts and 15 chapters that follow the phases of the plan’s development (and the FEMA LHMP checklist or “crosswalk”) as follows: Part 1 Prerequisites: introduction, acknowledgements, adoption, and summary Part 2 The Planning Process Part 3 Risk Assessment Part 4 Mitigation Strategies Part 5 Plan Implementation and Maintenance The Risk Assessment (Part 3) is organized into specific hazards by chapter (Chapters 4-12.) Within each of these chapters all elements required by the FEMA crosswalk are addressed and the sections and subsections of each of these chapters follow the section numbering of the crosswalk. (e.g. Subsection 3.1 Identifying Risk Hazards is §7.3.1 in Chapter 7–Drought) Each of the specific hazard Risk Assessment chapters contains the following subsections: 3.0 Risk Assessment 3.1 Hazard Identification 3.2 Hazard Profile including subsections on location, extent, previous occurrences, and probability of future events. 3.3 Assessing Vulnerability 3.4 Identifying Structures 3.5 Estimating Potential Losses 3.6 Analyzing Development Trends Mitigation Strategy (§4.0 through §4.2) is addressed briefly under each hazard chapter and covered comprehensively in Part 4. Goals and actions specific to a particular hazard are included within the hazard chapter and are labeled by hazard (e.g. Earthquake Goal 1). Goals, objectives and actions, which apply to one or more potential hazards, are listed in Part 4. Goals, objectives and action items identified as part of the mitigation strategy were formulated in collaboration with the departments responsible for implementation of the actions. These goals and supporting actions are not new but have been taken from various plans adopted by the Board of Supervisors including the General Plan Safety Element, the 2005 Urban Water Management Plan, the Integrated Water Plan, the Emergency Management Plan and several fire safety plans. Crosswalk sections that do not apply to the County of Santa Cruz such as multi-jurisdiction plan requirements are not included. Each part of the LHMP includes required elements specified under Section 201.6 of Title 44 of the Code of Federal Regulations (44 CFR). Since one of the objectives established for the LHMP is to achieve compliance for the County of Santa Cruz under the DMA, the requirements specified for program compliance are often cited at the beginning of a subsection to illustrate County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 1 how that subsection attempts to comply with the requirement. At the end of this LHMP are Appendix A through Appendix O. These appendices include vital information or explanations to support the main content of this plan. Technical terms, acronyms, and abbreviations are used throughout this document. To aid the reader, technical terms used are defined in the glossary. The list of acronyms and abbreviations defines all shortened forms used in hazard mitigation planning and/or this LHMP. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 2 PART 1 — INTRODUCTION AND ADOPTION People and property in Santa Cruz are at risk from a variety of hazards, which have the potential to cause widespread loss of life, damage to property, infrastructure, and the environment. Some hazards are natural, such as earthquakes, while others are natural hazards exacerbated by the use of land, such as building along a cliff and development within floodplains. A natural hazard can result in damages and hardships for an entire community for many years following the event. Flooding, drought, earthquakes and cliff retreat have all occurred in the County within the last fifty years. Flooding on the San Lorenzo River had caused the most severe damage in the County until 1989 when the Loma Prieta earthquake occurred. There is a very strong possibility of an earthquake equal to or larger than the Loma Prieta quake occurring in the Santa Cruz area. (Table 4-2) within the next 100 years. The County of Santa Cruz is somewhat unique in that the water service is provided by the Soquel Creek Water District, Pajaro Valley Water District, San Lorenzo Water District, and the City of Santa Cruz, all of which are independent water agencies. Many rural properties supply their own water via wells. Hazard Mitigation The purpose of hazard mitigation is to implement and sustain actions that reduce vulnerability and risk from hazards, or reduce the severity of the effects of hazards on people and property. Mitigation actions include both short-term and long-term activities which reduce the impacts of hazards, reduce exposure to hazards, or reduce effects of hazards through various means including preparedness, response and recovery measures. Effective mitigation actions also reduce the adverse impacts and cost of future disasters. The County of Santa Cruz developed this Local Hazard Mitigation Plan (LHMP) to create a safer community. The County of Santa Cruz LHMP represents the County’s commitment to reduce risks from natural and other hazards, and serves as a guide for decision-makers as they commit resources to reducing the effects of potential hazards. The County of Santa Cruz LHMP serves as a basis for the State Office of Emergency Services (OES) to provide technical assistance and to prioritize project funding. (Code of Federal Regulations (CFR) §201.6.) For disasters declared after November 1, 2004, the County of Santa Cruz must have an approved LHMP pursuant to CFR §201.6 in order to receive FEMA Pre-Disaster Mitigation (PDM) project grants or to receive post-disaster Hazard Mitigation Grant Program (HMGP) project funding. The LHMP is written to meet the statutory requirements of the Disaster Mitigation Act (DMA) 2000, enacted October 30, 2000 and Title 44 of the Code of Federal Regulations CFR Part 201–Mitigation Planning, Interim Final Rule, published February 26, 2002. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 3 ACKNOWLEDGEMENTS Santa Cruz County Board of Supervisors John Leopold Ellen Pirie Neal Coonerty Tony Campos Mark Stone First District Supervisor Second District Supervisor Third District Supervisor Fourth District Supervisor Fifth District Supervisor Project Committee Staff Department Position Paul Horvat Mark Deming Laurie Lang Bruce Laclergue Antonella Gentile Kent Edler, P.E. John Ricker Paul Garcia Matt Price Gulla Gisladottir David Reid Susann Rogberg Terry Reynolds Karen Christensen Richard Sampson Kathleen Lineberry Angela Bernheisal Office of Emergency Services Planning Office of Emergency Services Dept. of Public Works Planning Dept. Planning Dept. Environmental Health Geographic Information Systems Geographic Information Systems Geographic Information Systems Public Works Public Works Public Works Resource Conservation District Cal Fire Cal Fire CalFire Manager Assistant Director LHMP Coordinator Flood Control Program Manager Resource Planner Senior Civil Engineer Water Resources Division Director Sr. GIS Analyst GIS Coordinator Sr. GIS Analyst Sr. GIS Analyst Assistant Director Superintendent of Roads Executive Director Division Chief Captain Forester I Technical Advisors Organization Position Gary Griggs Tom Evans Patsy Hernandez Cathlin Atchison UCSC NOAA Red Cross SC City Scientist Meteorologist Emergency Services Director Project Manager County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 4 Emergency Management Council MEMBER Paul Horvat Kim Smith Craig Wilson Susann Rogberg David Lee John Ferreira Celia Barry Dr. Poki Namkung Robert Kennedy Randy Fedak Ken Corbishley Christina Manriquez Tom Barnett Wendy Sarsfield Jeff Trapp Charles “Cap” Pennell Patsy Hernandez Mark Carbonero Richard Ehle Robert Solick John Wilson Jeff Hartley Ciro Aguirre Dr. David McNutt Bill Ryan JoAnn Allen Barbara Doss Marianne Lindgren Charles Eadie Wayne Heimsoth Jeff Terpstra Tom Hern Carl Johnson Liz Taylor-Selling Pat Jocius County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 AGENCY Office of Emergency Services (OES) Manager OES Documentation Lead Sheriff-Coroner of the County or designee Public Works Director Planning Director of the County or designee Area Fire Coordinator of the Fire Chief’s Association or designee County Emergency Medical Services Manager County Health Officer Public Health Director Human Resources Agency Administrator or designee Agricultural Commissioner of the County or designee California Highway Patrol CAL TRANS Pacific Gas and Electric UC Santa Cruz or designee Amateur Radio (RACES) American Red Cross Local Emergency Communications Committee for Monterey (EAS) Representative for City of Capitola Representative for City of Santa Cruz Representative of City of Scotts Valley Representative of City of Watsonville Santa Cruz Metropolitan Transit District Medical Society of Santa Cruz County Dominican Santa Cruz Hospital/Safety & Security County Office of Education Sutter Maternity and Surgery Center Watsonville Community Hospital Santa Cruz County Chamber of Commerce Public member from 1st Supervisorial District Public member form 2nd Supervisorial District Public member from 3rd Supervisorial District Public member form 4th Supervisorial District Public member form 5th Supervisorial District At Large Community Member 5 Summary The physical environment of Santa Cruz County is one of the most beautiful and diverse in California. The topography is varied, containing the redwood forests in the Santa Cruz Mountains in the north and northeast, the mid-County coastal terraces where a large portion of the County’s population resides, and the alluvial plains of South County, which is predominantly in agricultural use. The central California coast location and the County’s topographical features contribute to the ideal Mediterranean climate of Santa Cruz County. FIGURE 1. COUNTY LIMITS OF SANTA CRUZ WITH GENERAL PLAN BOUNDARIES Natural hazards that have affected Santa Cruz in the past and those that may affect it in the future can be identified with a high degree of probability. Flooding, earthquakes and cliff retreat have all occurred in the County within the past thirty-five years. The County is prone to reoccurring droughts and will periodically witness flood conditions. Until 1989, flooding on the San Lorenzo River had caused the most severe damage in the City. However, the Loma Prieta earthquake changed that history. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 6 On October 17, 1989, the Loma Prieta earthquake, the largest earthquake to hit an urban area in California since the 1906 San Francisco earthquake, struck the County of Santa Cruz. The earthquake destroyed 674 dwellings, 32 mobile homes and 310 businesses within the county and the State Office of Emergency Services estimated monetary damages to residential buildings at $176 million and $98 million to commercial structures. 1 While we cannot predict or protect ourselves against every possible hazard that may strike the community, we can anticipate many impacts and take steps to avoid or reduce the harm they will cause. This Local Hazard Mitigation Plan (LHMP) is part of an ongoing process to evaluate the risks that different types of hazards pose to Santa Cruz and will engage the County and the community in dialogue to identify the most important steps to pursue in order to reduce these risks. The County of Santa Cruz and community members have been working together during the past several years to identify and address the risks posed by earthquakes, floods, fires and other potential hazards. Many measures such as vegetation management, a comprehensive water management plan, and seismic retrofits have significantly reduced the community’s vulnerability to these hazards. Over time, this constant focus on disaster preparation will make the County a much safer and more sustainable community. It is the intention of this plan to meet the requirements of the Federal Disaster Mitigation Act of 2000. Section 322 of the Act specifically addresses mitigation planning at the state and local levels. Following approval of this LHMP by FEMA, the County of Santa Cruz will be eligible to apply for mitigation grants before disasters strike. Mitigation Plan Objectives and Actions Santa Cruz strives to be a disaster-resistant county that can avoid, mitigate, survive, recover from, and thrive after a disaster while maintaining its unique character and way of life. County government should be able to provide critical services in the immediate aftermath of a devastating event of any kind. The people, buildings and infrastructure of Santa Cruz should be resilient to disasters. The County’s overall objective is to have basic government services and commercial functions resume quickly after a damaging earthquake or other significant event. This Plan has four primary goals for reducing disaster risk in Santa Cruz: 1. Avoid or reduce the potential for loss of life, injury and economic damage to Santa Cruz residents from earthquakes, wildfires, floods, drought, tsunami, coastal erosion, landslide and dam failure. 2. Increase the ability of the County government to serve the community during and after hazard events. 3. Protect Santa Cruz’s unique character, scenic beauty and values from being compromised by hazard events. 4. Encourage mitigation activities to increase the disaster resilience of institutions, private companies and systems essential to a functioning Santa Cruz. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 7 CHAPTER 1—ADOPTION BY COUNTY BOARD OF SUPERVISORS RESOLUTION County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 8 CHAPTER 2—COMMUNITY PROFILE Sources: Santa Cruz County Comprehensive Economic Development Strategy (CEDS) 2008 Annual Update (Jan. 2009) Figure 2 County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 9 Community Profile The County of Santa Cruz is situated on the northern shore of Monterey Bay (see Figure 2). Our county is home to the Monterey Bay Marine Sanctuary and University of California at Santa Cruz (UCSC) Longs Marine Lab. The bay, beaches, and coastline are appreciated by the community as a valuable natural resource as well as a key economic resource. This location along the coast also presents several potential hazards to the community such as tsunami, coastal erosion, and flooding. The County’s mild weather, proximity to several northern California metropolitan centers, and scenic and recreation resources make it a popular day and extended-stay recreation area. As a result, the population is subject to large seasonal variations due to an influx of visitors during summer and other peak recreational periods. Planning for potential hazards in Santa Cruz must address the safety of its visitor population as well as residents, large student population, and workers within the community. The County occupies a picturesque location along the coast of the Pacific Ocean, between the Monterey Bay and the Santa Cruz Mountains. It is a land of steep coastal bluffs, deep mountain canyons, redwood, oak and madrone forests, open meadows, and beaches. This picturesque location also contributes to the potential hazards. Parts of Santa Cruz County, such as the City of Santa Cruz downtown area, are located within a flood plain. There are only four bridges across the river connecting the two sides of the city. Past experience has shown that losing even one of these bridges in a disaster presents significant problems in addition to traffic impacts. The County’s Mediterranean climate is characterized by warm, dry summers and mild, rainy winters. Warm temperatures and low precipitation are the norm from approximately April through October. Cooler temperatures and heavy rains dominate November through March. Though winters are typically mild, colder winds from inland regions with more continental climates can result in short-term cold snaps. During the year the average temperature is approximately 56 degrees. The average high temperature is 69 degrees Fahrenheit and the average low temperature is 44 degrees Fahrenheit. 2 Because of this temperate climate, extreme heat is rarely a threat to the community. Both summer and winter temperatures are moderated by the marine influence and summer fog is a common occurrence. Winds are generally northwesterly and seldom reach severe intensities. The Santa Cruz Mountains form a natural barrier to winds from the north and from the hot interior valleys. Rainfall varies throughout the county, from approximately 80 inches per year in Bonny Doon, to approximately 22 inches per year in the Watsonville area. County wide over the past 25 years, it has ranged from 15 inches in 1989 to 59.8 inches in 1983 with an average 32 inches of rainfall annually. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 10 TABLE 2-1. TEMPERATURE AVERAGES FOR SANTA CRUZ Average High/Low Temperature January 60°/38° F (15° /3° C) August 76°/51° F (24°/10°C) Average Rainfall January 6.16 inches (156 mm) August 0.07 inch (1.77 mm) TABLE 2-2. COUNTY OF SANTA CRUZ POPULATION AND HOUSEHOLD GROWTH – 2000 CENSUS Population Total Population Sex and Age Male Female Median Age (years) 18 & Under 65 years and older Disabled (5 years and older) Total Households Persons per household Median household income Persons below poverty Housing Characteristics Total Housing Units Occupied Housing Units Vacant Housing Units Owner Occupied Housing Units Renter Occupied Housing Units Housing Units in multi-unit structures Number 253,137 Percent 100% 126,822 126,315 37.0 54,931 26,326 26,892 91,139 2.71 $62,849 26,832 50.1% 49.9% 21.7% 10.4% 11.5% 100% 102,311 93,518 8,793 56,150 37,368 20,986 100% 91.4% 8.6% 60% 40% 20.4% 10.6% As noted in the table above, approximately 11.5% of county residents are disabled. Also, 10.4% of the county’s population is age 65 or above. It is important to consider these special populations in creating a hazard mitigation plan, as they may need extra assistance during emergencies. The County’s Emergency Management Plan (EMP) does address special population needs and this hazard plan was written with reference to the EMP. The University of California at Santa Cruz (UCSC) The County of Santa Cruz is home to the University of California at Santa Cruz (UCSC). The main University campus consists of over 2,000 acres on the northwest side of the City of Santa Cruz off High and Bay Streets. Approximately 53 percent of the campus, including most of the developed area, is located within the City of Santa Cruz limits, and the remainder of the campus lies in the unincorporated area of Santa Cruz County. In addition to the main University campus, the University also has a Marine Lab Facility at the north side of the County situated along the coast. Much of the University infrastructure and services are at least somewhat dependent on the City and County of Santa Cruz. UC Santa Cruz receives water and sewer treatment services from County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 11 the City of Santa Cruz. In normal and wet years, the water supply system is capable of meeting the needs of the current population, but even without population increases, the system is highly vulnerable to shortages in drought years. The City and the University are also linked through mutual aid agreements in areas such as fire services. The University has a current enrollment of approximately 15,000 students supported by approximately 4,400 faculty and staff. The University adopted its own Hazard Mitigation Plan in 2005. It also has an Emergency Response Plan that can be found online at: http://disaster.ucsc.edu. This plan provides details about hazard response, vulnerabilities and mitigation measures for the University community. Cabrillo Community College The county is also home to one of the highest rated community colleges in the state. Cabrillo Community College sits on 160 acres overlooking Monterey Bay. The main campus is located in Aptos, on the north side of Hwy 1. There are two satellite campuses, one in the City of Watsonville and the other in Scotts Valley. The college also owns seven acres in Bonny Doon for use of anthropology and archeology students. The College has a current enrollment of approximately 17,000 students supported by 933 faculty and staff. The developed area (existing and approved) of the campus consists of 40 buildings with over 571,702 square feet. There is no student housing on campus but there is a newly built student center, which includes a Health Center. The College contracts with the County Sheriff’s Department to provide all law enforcement services. It is also dependent on the County of Santa Cruz for fire protection and other services such as water and sewer. The College has developed an Emergency Response Plan (BP4330) as of Sept. 11, 1989. This plan clearly delineates areas of responsibility for staff and partner agencies and specifically addresses earthquake, fire, flood, storms, landslide and other hazards that might occur on campus. This policy also defines when a state of emergency should be declared on campus and the steps necessary to address said emergency. California Polytechnic University Swanton Pacific Ranch is a working ranch owned by Cal Poly. It has three distinct operations; FSC certified selective forestry, natural grass-fed beef and certified organic crops. Located on 3200 acres, the exceptional diversity of this property, and the greater Scotts Creek watershed, provide remarkable conditions for agriculture production, which support several unique educational programs and research opportunities based on site. The ranch was recently threatened by the Lockheed Fire in August 2009, but no damage occurred. Household Income and Education The median household income for the County of Santa Cruz in 2007 was an estimated $62,849, compared to $59,928 for the State of California. Residents of the County of Santa Cruz are highly educated, with more than 34 percent of residents over age 25 having achieved a bachelor’s degree or higher by 2000. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 12 Residents’ Place of Work In addressing potential hazards, it is significant that over 33,000 county residents commute to neighboring counties for work. 3 This represents approximately 26% of the total number of workers in the county. Over 21,000 commute to work in Santa Clara County, which is connected to Santa Cruz County by Hwy. 17, a winding, four-lane mountain pass prone to traffic accidents and small slides, especially during the rainy season. Approximately 5,100 county residents commute to Monterey County via Hwy.1, portions of which are two lanes and prone to accidents, which cause major traffic jams. There are far fewer commuters into the county. Just over 14,300 workers commute to Santa Cruz, the vast majority of which (7,601) come from Monterey County via Hwy 1 (Appendix N). As previously mentioned, this can be problematic due to accidents, which tie up this main artery to the coast. FIGURE 3. KEY TRANSPORTATION ROUTES TO AND WITHIN SANTA CRUZ COUNTY Five major state highways connect Santa Cruz County with adjacent counties. Highway 1 leads along the coast from San Francisco south to the cities of Santa Cruz, Capitola and Watsonville and then on to Monterey. Highway 9 traverses the County from the City of Santa Cruz through the unincorporated towns of Felton, Ben Lomond, Brookdale and Boulder Creek, which are all located in the San Lorenzo Valley. Highway 17 also crosses the Santa Cruz Mountains into Santa Clara County passing through the City of Scotts Valley. Highways 129 and 152 join the City of Watsonville with neighboring Santa Clara County. The Santa Cruz Metropolitan Transit District (Metro) provides bus service throughout Santa Cruz County. Metro also operates bus service between the County of Santa Cruz and Santa Clara County. One small airport County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 13 accommodating private planes is located in Watsonville and a second small airport is maintained in Bonny Doon for the use of CalFire Dept. Route 9 is the only viable access to the San Lorenzo Valley, serving the unincorporated communities. Bonny Doon is accessible via either Highway 9 or via Highway 1 and then inland near Davenport. Davenport and Watsonville, and indeed, most other mid county locations are all accessible from Highway 1. The county maintains a distinction between urban and rural areas through the use of a stable Urban/Rural Boundary, consistent with the California Coastal Act of 1976 and measure J, a local growth management referendum of 1978. The Urban/Rural Boundary is represented by an Urban Services Line (USL) and a Rural Services Line (RSL). Urban concentrations of development are located within the four incorporated cities of Scotts Valley, Santa Cruz, Capitola and Watsonville and in the unincorporated areas of Live Oak, Soquel, Aptos, and Freedom as defined by the USL (See Appendix L). It is basic county policy to direct a large share of the County’s growth into the areas within the USL to facilitate the provision of services for future growth, preservation of the environment and hazard mitigation. Economic Trends The dominant economic activities are centered in the agricultural and food processing of the South County and in service and tourism in the North County. Other economic activities include high technology, quarrying, forestry, wood products, fishing and other manufacturing. As previously noted, there are two major educational institutions in our county: Cabrillo Community College located in mid-county and the University of California at Santa Cruz (UCSC) located in the north county area. Santa Cruz County has seen a modest growth in key economic indicators over the past fourteen years such as retail sales, agricultural production and net job growth, to name a few 4. The greatest job growth occurred in “natural resources, mining, and construction” categories (42.1%) and the government category (28.3%). 5 Information technology and manufacturing suffered the highest job losses during this same time period. While jobs in the agricultural sector decline 27.3%, the production value of local crops increased from $230 million dollars in 1998 to almost $500 million in 2007. This is an important consideration in hazard mitigation planning, as much of the unincorporated area of the county is agricultural land, some of which lies in the flood plain. Proper flood mitigation could save millions of dollars in lost crops. While net job growth increased modestly from 1998 to 2007, the State Employment Development Department reported a decline of approximately 800 jobs between October of 2007 and October of 2008 and this decline is expected to continue through 2009. 6 Retail sales accounted for a large portion of revenue for the county, increasing 40.5% between 1998 and 2006 7. This figure includes sales tax revenues from the entire county, including the cities of Watsonville, Scotts Valley, Capitola and Santa Cruz. The unincorporated area of the county experienced a 35.4% increase in sales tax revenue in the same time period. Community Vision The County of Santa Cruz General Plan includes a section on Public Safety, which addresses many of the potential hazards addressed in this plan. The overall goals guiding the Public County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 14 Safety Element of the General Plan are as follows: To protect human life, private property and the environment. To minimize public expenses by preventing inappropriate use and development or location of public facilities and infrastructures in those areas, which by virtue of natural dynamic processes or proximity to other activities, present a potential threat to the public health, safety and general welfare. The Public Safety Element of the General Plan also identifies major hazards that may occur within our county, policies that address each hazard and mitigation factors. It provides information on all pertinent county policies relating to hazard mitigation, as well. The General Plan has informed this LHMP. Working with the Planning Department collaboratively on this LHMP supports a broader vision of what factors need to be considered in order to protect the health and welfare of our residents. General Plan Guiding Principles The overall goals and guiding principles for the Land Use Element of the General Plan, which needed to be considered in our Local Hazard Mitigation Plan, are as follows: Population and Residential Growth Goals: To provide an organized and functional balance of urban, rural, and agricultural land use that maintains environmental quality, enhances economic vitality, protects the public health, safety and welfare, and preserves the quality of life in the unincorporated areas of the county. Rural Residential Siting and Density: To achieve patterns of rural residential development that are compatible with the physical limitations of the land, the natural and cultural resources of the County, the availability of public services, and protection of the natural environment. Village, Town, Community and Specific Plans: To continue using village, town, community and specific plans to provide a planning framework to guide future public and private improvements in town centers and other concentrated urban and rural areas, to provide a higher level of planning detail and involvement. Critical Structures Within Santa Cruz County The County of Santa Cruz owns or leases a large number of facilities and critical infrastructures. These buildings, bridges, culverts etc. are used for various purposes including government administration, emergency services, public works, and recreation. After the 1989 Loma Prieta earthquake, many of these structures were examined for seismic safety. A list of these facilities appears in Appendix D and maps of the location of these structures follows on the next pages (figure 4 & 5). County of Santa Cruz Owned Infrastructure consists of the following elements: All sanitation pump stations and treatment plants All county maintained bridges and major culverts County rain and stream gauges Pajaro and Salsipuedes levee flood gates Public Works Yards Davenport Water Treatment Facility 38th Ave. Drainage Facility County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 15 FIGURE 4. COUNTY OWNED CRITICAL INFRASTRUCTURE LOCATIONS County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 16 FIGURE 5. LOCATION OF LEVEE FLOOD GATES Critical Facilities Not Owned by the County Hospitals and schools are some of the critical facilities not owned by the County but designated as Disaster Medical Facilities or shelters in the Public Health Emergency Preparedness Plan. For a complete list, please see Appendices E, F and G. There are three hospitals within the county limits: Dominican Santa Cruz Hospital, Watsonville Community Hospital, and Sutter Maternity and Surgery Center. Of the three, only Dominican and Watsonville have emergency rooms. All three hospitals are designated for use during Public Health emergencies. There are also several skilled nursing facilities, rehabilitation centers, medical clinics, and longterm care facilities within the county. The Santa Cruz County Office of Education (COE) oversees all schools within the county, some of which have been used in the past as emergency operation centers and emergency shelters. The COE has an Emergency Plan, which is incorporated within this LHMP. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 17 FIGURE 6. CRITICAL FACILITIES NOT OWNED BY THE COUNTY OF SANTA CRUZ Historical Structures The Planning Department keeps an inventory of historic sites and properties within the county. A historic evaluation is provided for each site which provides the basis for classifying the properties. The evaluation and rating of these properties in this inventory is based upon guidelines published by the National Park Service for placement on the National Register of Historic Sites. A review of this list revealed that all of the properties are privately owned except for Wilder Ranch State Park, which is under the authority of the state government. There were no historic sites or properties under the authority of the county government. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 18 PART 2 — THE PLANNING PROCESS The Purpose of the Plan The Planning Process Documentation of the Planning Process Local Capabilities Assessment and Integration Community Participation County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 19 CHAPTER 3 — THE PLANNING PROCESS The Purpose of the Plan The Federal Disaster Mitigation Act (DMA) of 2000 (Public Law 106-390), commonly known as the 2000 Stafford Act Amendments, was approved by Congress on October 10, 2000. To implement the DMA 2000 planning requirements, FEMA prepared an Interim Final Rule, published in the Federal Register on February 26, 2002, which established planning and funding criteria for states and local communities. This act required state and local governments to develop hazard mitigation plans as a condition for federal grant assistance. For the PreDisaster Mitigation (PDM) program, local jurisdictions must have an approved mitigation plan to receive a project grant. Prior to 2000, federal legislation provided funding for disaster relief, recovery, and some hazard mitigation planning. The DMA improves upon the planning process by emphasizing the importance of community planning for disasters before they occur. Using this initiative as a foundation for proactive planning, the County of Santa Cruz developed this hazard mitigation plan in an effort to reduce future loss of life and property resulting from disasters. Through careful planning and collaboration among public agencies, stakeholders, and citizens, it is possible to avoid or minimize losses that can occur from disasters. Hazard mitigation is any action taken to permanently eliminate or reduce long-term risks to human life and property from natural hazards. Along with preparedness, response, and recovery, mitigation is an essential element in emergency management. Disasters can have significant impacts on communities. They can destroy or damage life, property, and infrastructure, local economies, and the environment. This LHMP is intended to assist the County of Santa Cruz in reducing its risk from all hazards by identifying resources, information, and strategies for risk reduction. The plan will also help guide and coordinate mitigation activities throughout the County. Building on a tradition of progressive planning and past mitigation successes, the County of Santa Cruz planning team set out to develop a plan that would meet the objectives summarized below. The plan would meet or exceed program requirements specified under the DMA The plan would meet the needs of the County of Santa Cruz The plan would coordinate existing plans and programs so that high priority initiatives and projects to mitigate possible disaster impacts would be funded and implemented. The plan would also create a linkage between the LHMP and established plans such as the County’s General Plan and Emergency Management Plan so that they will work together in achieving successful disaster mitigation. It should be noted that DMA compliance is not the sole purpose of this LHMP. Santa Cruz County has experienced a number of significant disasters, which has fostered a practice of proactive planning and program implementation. This practice is further enhanced by the development of this LHMP. Multiple objectives drive this planning effort, one of which is DMA compliance. Elements and strategies included in this plan were selected not only because they meet a program requirement but also because they meet the needs of the community. PLANNING PROCESS This section describes the process in which the plan was developed. This includes the federal requirement followed by the County’s actions applied to this process. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 20 DOCUMENTATION OF THE PLANNING PROCESS 2.1 Documentation of the Planning Process Requirement §201.6(b): In order to develop a more comprehensive approach to reducing the effects of natural disasters, the planning process shall include: (1) An opportunity for the public to comment on the plan during the drafting stage and prior to plan approval; (2) An opportunity for neighboring communities, local and regional agencies involved in hazard mitigation activities, and agencies that have the authority to regulate development, as well as businesses, academia and other private and non-profit interests to be involved in the planning process; and (3) Review and incorporation, if appropriate, of existing plans, studies, reports, and technical information. Requirement §201.6(c)(1): The plan shall document the planning process used to develop the plan, including how it was prepared, who was involved in the process, and how the public was involved. The County of Santa Cruz has developed a local hazard mitigation plan. The County Office of Emergency Services took on the initial responsibility for development of the plan. The initial phase of the planning process established a project team made up of representatives from various County government departments responsible for different aspects of the hazard mitigation plan including Planning and Building, Public Works, Fire, and Geographic Information Systems (GIS). From this group, project team leaders were identified. Team leaders included Paul Horvat, Emergency Operations Manager, Mark Deming, Planning Dept. Assistant Director and Laurie Lang, LHMP Coordinator. The project team was formed as a task group to develop the plan. Meeting dates were set based on progress and focus. The project team invited interested parties such as UCSC, Cabrillo College, the cities of Capitola, Watsonville, Scotts Valley and Santa Cruz, the local American Red Cross as well as scientific and technical specialists at the local, state, and national level to review the draft at various stages. The project team is listed under acknowledgements in Part 1 (pg. 4). The plan was developed between May 2008 and December 2009. The project team leaders met once per week and the project team met approximately once per month from September 2009, through December 2009, and then as needed in 2010 until the draft plan was circulated for a 30-day public review on January 15, 2010. The project team leaders identified characteristics and potential consequences of natural hazards that are a potential threat to the County of Santa Cruz. With the understanding of the risks posed by the identified hazards, the team determined priorities and assessed various methods to avoid or minimize any undesired effects. Responsible departments were consulted at several points in the development of the goals, objectives and actions. As a result, the mitigation strategy, including goals, objectives and actions, was determined, followed by an implementation and monitoring plan. This monitoring plan included tracking of hazard mitigation projects, changes in day-to-day County operations, and continued hazard mitigation development. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 21 Local Capabilities Assessment and Integration 2.2 Local Capabilities Assessment (State of OES Requested Information) Requirement §201.4(c)(3)(ii): Of the Federal Register Interim Final Rule Title 44 of the Code of Federal Regulations 44 CFR Parts 201 and 206 states, The State mitigation strategy shall include a general description and analysis of the effectiveness of local mitigation policies, programs and capabilities. This assessment of the mitigation goals, programs and capabilities included a review of the following items: 1) Human and technical resources 2) Financial resources and funding sources 3) Local ordinances, zoning and building codes 4) On-going plans or projects The LHMP was informed by The General Plan Safety Element, the Emergency Management Plan, the Urban Water Management Plan, the Santa Cruz City Water Department Water Conservation Plan, County ordinances, zoning and building codes and the Capital Improvement Program (CIP.) Consistency between these plans, programs and policies was reviewed by using these approved plans and policies as a foundation for the LHMP and by consulting with the departments responsible for the various plans and programs. In reviewing the effectiveness of local programs, Appendix H lists Successful Programs that have been implemented by the County. While these programs and the updated Emergency Management Plan have increased the County’s hazard mitigation capabilities, funding availability is the limiting factor in the implementation of additional identified hazard mitigation programs. The Project Team leaders met several times with county staff and members of the Planning Department to insure that the LHMP was consistent with the General Plan Safety Element. The project leaders met with county staff in the Environmental Health Dept. to incorporate hazard mitigation efforts identified by the various Water Departments within the county. Project leaders met with Fire Department staff to insure that the LHMP was consistent with the current and planned programs and fire safety plans. The project leaders also met with the County GIS coordinator to insure that maps were consistent with those in the General Plan and were accurate as of the draft publication date. The County of Santa Cruz Emergency Services Manager, Paul Horvat, was part of the Project Team leadership and oversaw the review and incorporation of plans and studies for consistency with the LHMP. This included the county’s Emergency Management Plan with the following appendices: Flood Management Plan Earthquake Hazard Plan Dam Inundation Hazard Plan Wildland Fire Hazard Plan Tsunami Hazard Plan Community Participation Public input during the development of the mitigation plan assisted in shaping plan goals and mitigations, and integrating the LHMP with the Safety Element of the General Plan Update. The County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 22 Local Hazard Mitigation Plan was a topic of discussion at three public meetings of the Emergency Management Council. When the draft was completed, a 30 day public comment period was initiated. A public notice was placed in the local paper to invite the public to review and comment on the draft plan. Copies of the plan were made available at the Aptos, Live Oak and Felton Branches of the Santa Cruz Public Library and in the General Services Department at the County Administrative Building. A draft of the plan was posted on the County’s website with an interactive response option that provided an opportunity for interested members of the public to comment on the draft LHMP on the web. Those comments were incorporated into the final document. The draft LHMP was also sent to members of a technical committee, which consisted of national, state and local scientists and experts for review prior to creation of the Public Draft. Comments received were incorporated into the final draft LHMP. LHMP Meetings Date Type Project Team Leaders Subject Matter Expert Subject Matter Expert Consultant Project Team Leaders Consultant EMC Presentation and adoption of goals and objectives Consultant Project Team Leaders & GIS Project Team Project Team (CRS Team) Emergency Management Council – section review Project Team Crosswalk Review Project Team EMC Presentation of draft plan Project Team Leaders July 1, 2009 July 21, 2009 July 28, 2009 July 29, 2009 August 3, 2009 September 2, 2009 September 3, 2009 In house In house - Flood In house – City of Santa Cruz In house – Civil Engineering In house In house – Civil Engineering Public October 8, 2009 October 13, 2009 October 15, 2009 October 29, 2009 November 5, 2009 In house In house In house In house Public December 9, 2009 December 16, 2009 January 7, 2010 January 11, 2010 In house In house Public In house County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 23 PART 3 — HAZARD IDENTIFICATION AND RISK ASSESSMENT Significant Risks Earthquakes and Liquefaction Wildfires Floods and Associated Coastal Storms Drought Tsunami Coastal Erosion Landslides Less Significant Risks Dam Failure Expansive Soils Unknown Risk Climate change Multi-Hazard Summary County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 24 IDENTIFICATION AND PROFILING OF HAZARDS Risk Assessment of Hazards in Santa Cruz 3.0 Risk Assessment: §201.6(c)(2): The plan shall include a risk assessment that provides the factual basis for activities proposed in the strategy to reduce losses from identified hazards. Local risk assessments must provide sufficient information to enable the jurisdiction to identify and prioritize appropriate mitigation actions to reduce losses from identified hazards.. It is important for a community’s risk assessment, mitigation and preparedness efforts to be founded on accurate information about the types and scale of damage hazards pose to the community. This section of the Plan contains a description of those hazards identified as potential significant threats to Santa Cruz – earthquakes, wildfires, floods, drought, tsunami, coastal erosion, and landslide as well as the lesser threats of dam failure and expansive soils – and the exposure and vulnerability of the County to these hazards. These risks have been identified based on historical information of hazard events including researching past disaster declarations in the County, input from geologic, climatic, and wildfire specialists and organizations as well as public comments and newspaper articles. Probable damage and the consequences to the county’s quality of life are described. The County of Santa Cruz has expanded and updated its GIS database, mapping critical facilities and hazard risk areas. Data from this mapping was used to determine hazards that present the greatest risk to the County. Each hazard type was mapped as a GIS layer. In some cases, the hazard layers were developed and provided by outside agencies. Estimated loss is based on assessment improvement values associated with the Assessment Roll dated 10/13/2009. The assessment improvement values were joined to the county’s parcel layer. The unincorporated parcels were queried out (which excluded the city parcels in the analysis). For each hazard type, the unincorporated parcels that fell within the hazard type were selected and the assessment improvement values were totaled. Valuation of parcels is based on improvement values as they appear on the Assessment Roll. They do not reflect potential sale or replacement value. ESRI’s ArcGIS software was used to develop the hazard layers and conduct the analysis. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 25 TABLE A-1. A REVIEW OF ALL HAZARDS WITHIN THE COUNTY OF SANTA CRUZ Hazard Risk Why/Why Not Avalanche Climate Change Coastal Erosion No Unknown Major Coastal Storm Dam Failure Included Lesser Drought Earthquake Expansive soils Extreme Heat Flood Hailstorm Hurricane Land subsidence Landslide Liquefaction Winter Snow Storm Tornado Tsunami Major Major Major No Major No No No Major Included No No Major Volcano Wildfire No Major The county is not in an avalanche area Ongoing Research Past history indicates probability is high, potential for loss of life is low - potential for economic and infrastructure loss is high Included in Flood Plan Past history indicates that probability is low but potential loss of life is high Past history indicates probability is high Past history indicates probability is high Past history indicates probability is high Past history indicates probability is low Past history indicates probability is high Past history indicates probability is low Past history indicates probability is low Past history indicates probability is low Past history indicates probability is high Included with earthquake Past history indicates probability is low Past history indicates probability is low Past history (200 Years) indicates probability is low but potential for loss of life and property could be high Does not affect county Past history indicates probability is high 3.1 Identifying Hazards - §201.6(c)(2)(i): The risk assessment shall include a description of the type of all natural hazards that can affect the jurisdiction. TABLE A-2. HAZARD SCREENING FOR COUNTY Risk Very Significant Risk Earthquake (including liquefaction) Wildfire Flood (including coastal storms) Drought Tsunami Coastal Erosion Landslide County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 Affected Areas Entire County Wildland/urban interface areas San Lorenzo River floodplain Pajaro River floodplain Soquel Creek in Soquel Village Entire County Coastal Areas Coastal Areas Various areas (see map) 26 Lesser risk Dam Failure Expansive Soils Affected Areas San Lorenzo Valley Various areas (see map) The County of Santa Cruz is exposed to a number of natural hazards that vary in their potential intensity and impact. This mitigation plan addresses six high-risk natural hazards, selected because of the likelihood of occurrence or the potential consequences, as well as two additional hazards that present either less risk of occurrence or extent of damage. The natural hazards: floods, earthquake, and tsunami are of great concern because they can occur independently, or in combinations that can trigger secondary hazards such as dam failure. Another high-risk hazard, drought, can exacerbate the potential for wildfires. The natural hazards included in this plan were identified through a community-based process including input from scientific experts in various fields and in conjunction with the update of the General Plan including the Safety Element. The Local Hazard Mitigation Plan (LHMP) was the result of a number of public meetings, project team meetings, scientific expert and community input as well as suggestions submitted by community members of the county. Key contributors included members of the Project Team, the Emergency Management Council, Gary Griggs of the University of California at Santa Cruz, and county staff members who worked on programs and research that were incorporated in the General Plan and Safety element. Other natural hazards that are extremely rare or non-existent in the county are not included in this plan but are listed in Appendix A. The worst potential disaster that the County of Santa Cruz might face involves multiple hazards occurring at the same time. A major earthquake could trigger tsunamis, wildfires or floods, which would be exacerbated by damage to dams, stream culverts and storm drains. The County of Santa Cruz plans for and responds to emergency events in accordance with the Santa Cruz County Operation Area Memorandum of Understanding (MOU). The Emergency Management Plan describes the role and operation of the County departments and personnel during a major emergency. In addition to researching each hazard individually, this Plan explores how the hazards interact, and how mitigation activities for each hazard impact the overall disaster risk in Santa Cruz. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 27 CHAPTER 4 - EARTHQUAKES AND LIQUEFACTION 4.3.0 Risk Assessment 4.3.1 Identifying Earthquake Hazards 3.1 Identifying Hazards–Requirement §201.6(c)(2)(i): The risk assessment shall include a description of the type…of all natural hazards that can affect the jurisdiction. An earthquake is a sudden release of energy in the earth’s crust. Caused by movement along fault lines, earthquakes vary in size and severity. The focus of an earthquake is found at the first point of movement along the fault line, and the epicenter is the corresponding point above the focus at the earth’s surface. The size of an earthquake has been measured in various ways, the most familiar being the now obsolete Richter magnitude scale, which determines the amount of ground displacement or shaking that occurs near the epicenter. The Richter magnitude scale has now been replaced by the Moment Magnitude scale for medium and large sized earthquakes. While this scale attempts to characterize the amount of energy released by an earthquake, another scale - the Modified Mercalli Intensity Scale - measures ground shaking intensity in terms of perception and damage and takes into account localized earthquake effects (see Table 4-1). County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 28 TABLE 4-1. MODIFIED MERCALLI INTENSITY SCALE Intensity Severity 1-4 Instrumental to Moderate 5 Rather Strong 6 Strong 7 Very Strong 8 Destructive 9 Ruinous 10 Disastrous 11 Very Disastrous 12 Catastrophic Level of Damage No damage. Damage negligible. Small, unstable objects displaced or upset; some dishes and glassware broken. Damage slight. Windows, dishes, glassware broken. Furniture moved or overturned. Weak plaster and masonry cracked. Damage slight-moderate in well-built structures; considerable in poorly built structures. Furniture and weak chimneys broken. Masonry damaged. Loose bricks, tiles, plaster, and stones will fall. Structure damage considerable, particularly to poorly built structures. Chimneys, monuments, towers, elevated tanks may fail. Frame houses moved. Trees damaged. Cracks in wet ground and steep slopes. Structural damage severe; some will collapse. General damage to foundations. Serious damage to reservoirs. Underground pipes broken. Conspicuous cracks in ground; liquefaction. Most masonry and frame structures/foundations destroyed. Some well-built wooden structures and bridges destroyed. Serious damage to dams, dikes, embankments. Sand and mud shifting on beaches and flat land. Few or no masonry structures remain standing. Bridges destroyed. Broad fissures in ground. Underground pipelines completely out of service. Rails bent. Widespread earth slumps and landslides. Damage nearly total. Large rock masses displaced. Lines of sight and level distorted Damage from earthquakes varies with the local geologic conditions, the quality of construction, the energy released by the earthquake, the distance from the earthquake’s focus, and the type of faulting that generates the earthquake. Ground motion is the primary cause of damage and injury during earthquakes and can result in surface rupture, liquefaction, landslides, lateral spreading, differential settlement, tsunamis, building failure and broken utility lines, leading to fire and other collateral damage. Typically, areas underlain by thick, water-saturated, unconsolidated material will experience greater shaking motion than areas underlain by firm bedrock, but in some cases relief may intensify shaking along ridge tops. Fires and structural failure are the most hazardous results of ground shaking. Most earthquakeinduced fires start because of ruptured power lines and gas or electrically powered stoves and equipment, while structural failure is generally the result of age and type of building construction. Liquefaction is the transformation of loose, water-saturated granular materials (such as sand or silt) from a solid to a liquid state. Liquefaction commonly, but not always, leads to ground County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 29 failure. Liquefaction potential varies significantly and site-specific analysis is needed to accurately determine liquefaction potential in earthquake prone areas. Fault rupture and earthquake related Ground Cracking could occur in several locations within the County of Santa Cruz (see Figure 7 below). Several fault zones cross Santa Cruz County, and movement along these faults can cause fault-related surface deformation (e.g., surface fault rupture) where the fault reaches the surface of the ground. Both the County of Santa Cruz and the State of California have identified zones where the San Andreas and other active faults have and can cause fault-related surface deformation. Within these zones it is likely that movement along these faults will damage structures, roads, utilities, and other fixed facilities. In addition to these zones, other ground cracking was observed during the Loma Prieta earthquake and the San Francisco earthquake of 1906. Many of these ground cracks can be attributed to movement or consolidation of large and moderate sized landslides while other ground cracks were most likely related to ridge spreading. Although much of the ground cracking was found near the fault zones and in the Summit area of the county, other ground cracking was found on ridge tops throughout the County of Santa Cruz. FIGURE 7. FAULT ZONES WITHIN COUNTY OF SANTA CRUZ County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 30 4.3.2 Hazard Profile – Earthquakes and Liquefaction 3.2 Profiling Hazards – Requirement §201.6(c)(2)(i): The risk assessment shall include a description of the location and extent of all natural hazards that can affect the jurisdiction. The plan shall include information on previous occurrences of hazard events and on the probability of future hazard events. A. Location FIGURE 8. LIQUEFACTION AREAS WITHIN SANTA CRUZ COUNTY Past experience has shown that the entire county is vulnerable to earthquake. Within Santa Cruz County there are several active and potentially active faults. These include the San Andreas, San Gregorio, Zayante, the Monterey Bay Fault Zone, as well as numerous fault complexes and branches of these major faults. B. Extent: Magnitude or Severity Several of the faults located in Santa Cruz County are considered to be active (showing signs of recent geologic movement, within the last 10,000 years), or potentially active (showing evidence of Pleistocene or younger movement). Faults where movement has not occurred County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 31 during the Pleistocene are inactive and are not considered to pose a risk to any but the most critical structures. The most significant threat to the county is the San Andreas Fault zone, which passes through the Santa Cruz Mountains along the northern portion of the county. Based on records from the 1906 San Francisco earthquake, it is estimated that the maximum credible earthquake likely to occur along the San Andreas Fault would equal 8.3 M, which represents more than 30 times the energy released by the 1989 Loma Prieta Earthquake. Santa Cruz County was one of the hardest hit counties during that earthquake. C. Previous Occurrences The following is a list of previous events, dates, severity, level of damage, duration, sources of information used, and maps (where available) to show areas affected. While Santa Cruz has sustained numerous earthquakes throughout its history, the two most destructive ones were the 1906 San Francisco earthquake and the 1989 Loma Prieta earthquake. Moderate Sized Earthquakes before 1906: Four moderate sized earthquakes (estimated Richter magnitude 6 to 6.5) were recorded in Santa Cruz before the April 18, 1906 earthquake: a Richter Magnitude 6 earthquake on February 26, 1864 centered somewhere in the southern Santa Cruz Mountains, a 6.5 Richter Scale earthquake on October 8, 1865 centered in the Santa Cruz Mountains, a 6 Richter magnitude earthquake on March 26, 1884 centered in the Santa Cruz Mountains, and a 6.25 Richter magnitude earthquake in the Pajaro Gap on April 24, 1890. All of these together indicate that a pattern of earthquakes nearly the same size of the Loma Prieta earthquake have occurred in the recent past. Each of these earthquakes caused some damage, and would cause damage to homes today (N.B. all magnitudes cited are estimates based on descriptions of the damage which occurred). April 18, 1906: (Richter Magnitude: 8.3) There were no recorded deaths in Santa Cruz but the old courthouse partially collapsed and about 1/3 of the chimneys within the city of Santa Cruz were destroyed or damaged. Landsliding was observed throughout the Santa Cruz Mountains, and fault rupture was nearly continuous along the San Andreas fault zone, and nearby fault zones in the county of Santa Cruz. Infrastructure, including bridges, was destroyed, and broken mains and pipes shut off the water supply. October 1926: (Richter Magnitude: 6.1) Two large earthquakes occurred during this year. Three of the aftershocks cracked plaster in Santa Cruz, almost bringing down the chimneys of numerous buildings. It broke plate glass windows along Pacific Avenue. The city water main broke at Laguna Creek and articles fell from shelves at stores. October 17, 1989 (Richter Magnitude: 7.1) At 5:04 p.m., a magnitude 7.1 earthquake rocked the Monterey Bay and San Francisco Bay regions. The initial quake lasted only 22 seconds, although in the following two weeks, more than 4000 aftershocks were recorded, with 20 of these greater than magnitude 5 on the Richter Scale. The epicenter of the Loma Prieta earthquake was about 10 miles east-northeast of the city of Santa Cruz in the Aptos planning area on the San Andreas Fault. The Loma Prieta earthquake was the largest to strike California since 1906, causing 62 deaths and 3757 injuries. More than 12,000 people were left homeless and transportation, utilities and communications were disrupted. There was more than $6 billion in property damage. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 32 FIGURE 9. ISOSEISMAL MAP 8 ILLUSTRATING INTENSITY AND MAGNITUDE OF THE 1989 LOMA PRIETA EARTHQUAKE IN SANTA CRUZ County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 33 D. Probability of Future Events There are at least six major faults and fault systems within or near the County of Santa Cruz, placing it in an area of high seismic risk. Because earthquakes can cause severe damage over a long distance, the Santa Cruz area remains at risk from continued seismic activity along the many faults in the greater San Francisco Bay region. The reduction of seismic stresses that occurred in the Loma Prieta earthquake did nothing to relieve, and possibly increased, stresses within other faults, including other sections of the San Andreas Fault. To clarify the extent of future earthquake risk, a partnership of the United States Geologic Service, The California Geologic Survey, and the Southern California Earthquake Center was formed in September 2004 to provide a uniform forecast. Known as the Working Group on California Earthquake Probabilities 9, this group evaluated and systemized currently available historic and paleoseismic information to produce a probabilistic seismic hazards analysis to indicate the type of future earthquakes. One product of this analysis is a method of estimating the probability of ground shaking. The 30-year probability of an M ≥ 6.7 earthquake on the northern segment of the San Andreas Fault is 21% and on the San Gregorio Fault is 6%. Other faults within the region can also cause damage in the county, including the Hayward-Rogers Creek Fault that has a 31% probability of having an M ≥ 6.7 earthquake in the next thirty years 10. TABLE 4-2. TEN MOST LIKELY DAMAGING EARTHQUAKE SCENARIOS IN CALIFORNIA Ten most likely damaging Earthquake scenarios Rodgers Creek Northern Calaveras Southern Hayward (possible repeat of 1868 earthquake) Northern + Southern Hayward Mt. Diablo Green Valley-Concord San Andreas: Entire N. CA segment (possible repeat of 1906 earthquake) San Andreas: Peninsula segment (possible repeat of 1838 earthquake) Northern San Gregorio segment San Andreas: Peninsula + Santa Cruz segment 30-year probability 15.2% 12.4% 11.3% 8.5% 7.5% 6.0% 4.7% Magnitude 7.0 6.8 6.7 6.9 6.7 6.7 7.9 4.4% 7.2 3.9% 3.5% 7.2 7.4 Because the ten most likely future earthquakes in the Bay area occur on faults throughout the region, the impact and potential losses reported here reveal significant risk for the entire Bay area region including the County of Santa Cruz. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 34 4.3.3 Assessing Vulnerability: Overview 3.3 Assessing Vulnerability: Overview - Requirement §201.6(c)(2)(ii): The risk assessment shall include a description of the jurisdiction’s vulnerability to the hazards described in paragraph (c)(2)(i) of this section. This description shall include an overall summary of each hazard and its impact on the community. A. Overall Summary of Vulnerability to Earthquake The vulnerability of a community to earthquake hazard is based on a variety of factors including proximity to active and inactive faults, the age of structures, the density of the population and development, the value of property and infrastructure, the construction materials used in residential and non-residential buildings, and the location of critical facilities in a community. Recent history indicates that Santa Cruz has a very high vulnerability to earthquakes due to proximity to faults, density of population and development within the floodplains of the many creeks and rivers, which are subject to liquefaction. One or more moderate to large sized earthquake will likely shake the entire County of Santa Cruz during the life span of most residents. Older homes will be most affected by their age, structural design, and materials. Modern homes will normally fare better in earthquakes but 1989 showed that this isn’t necessarily the case. Some older homes fared better than newer ones due to location and design. A great earthquake on the San Andreas Fault will: Damage roads, bridges, and critical structures, and could severely damage most homes in the County. Liquefaction will occur along alluvial areas such as Pajaro Valley, parts of Capitola and Santa Cruz, and along streams such as Corralitos Creek, the San Lorenzo River, and other streams throughout the County of Santa Cruz. Fault Rupture will occur near the major faults as zoned by the County and State, and Ground Cracking will occur through the hillslopes and near the Fault Zones. As indicated in the sections on landsliding and coastal erosion, earthquakes can reactivate landslides and cause coastal bluff retreat, and also contribute to the initiation of other landslides and bluff failures. 4.3.4 Assessing Vulnerability: Identifying Structures A. Types & Numbers of Existing Buildings, Facilities & Infrastructure Past experience has shown that the entire county is vulnerable to earthquake. The entire downtown commercial area in the city is in a liquefaction hazard area. The remainder of the town is at risk for severe ground shaking as indicated by the maps below showing the probability of earthquake impacts to the Santa Cruz area within the next 50 years. These estimates were formulated using ESRI’s ArcGIS software. The earthquake hazard was mapped as a GIS layer. Estimated loss is based on assessment improvement values associated with the Assessment Roll dated 10/13/2009. The assessment improvement values were joined to the County’s parcel layer. The unincorporated parcels were queried out (which excluded the city parcels in the analysis). The unincorporated parcels that fell within the earthquake hazard areas were selected and the improvement values were totaled. They are County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 35 limited to ground motion-induced losses to buildings only. In other words, the losses to other elements of the built environment, such as transportation, lifeline and communication facilities are not reported. Furthermore, the losses reported are only the direct economic losses due to building damage, which consist of capital stock loss and income loss. This survey reviews 34 potential earthquake scenarios. Two of the ten most likely earthquake scenarios most damaging to Santa Cruz are shown on the following maps. Scenario N-9 shows a possible repeat of the 1906 San Francisco Earthquake and the intensity and potential damage to the County of Santa Cruz. The map indicates that the intensity would be up to IX or X, which represents violent or extreme perceived shaking and very heavy potential damage. The next map shows the peak ground acceleration for this earthquake and the following two maps show the estimated building damage and economic loss as a result of the Scenario-9 earthquake. Scenario N-7 shows the projected impacts of an earthquake along the Santa Cruz Mountains + Peninsula + North Coast and the potential damage to the County of Santa Cruz. The map indicates that the intensity would be VIII or IX, which represents severe to violent perceived shaking and moderate to heavy damage. The next map shows peak ground acceleration for this earthquake scenario and the following two maps show the estimated building damage and economic loss as a result of the Scenario-7 earthquake. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 36 FIGURE 10. SCENARIO N-9 REPEAT OF 1906 EARTHQUAKE County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 37 FIGURE 11. SCENARIO N-9 REPEAT OF 1906 EARTHQUAKE—BUILDING ECONOMIC LOSS BY COUNTY County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 38 FIGURE 12. SCENARIO N-9 REPEAT OF 1906 EARTHQUAKE LOSS BY CENSUS TRACT County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 39 FIGURE 13. SCENARIO N-7 SANTA CRUZ MOUNTAINS County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 40 FIGURE 14. SCENARIO N-7 SANTA CRUZ MOUNTAINS BUILDING ECONOMIC LOSS BY COUNTY County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 41 FIGURE 15. SCENARIO N-7 SANTA CRUZ MOUNTAINS BUILDING ECONOMIC LOSS BY CENSUS TRACT County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 42 4.3.5 Assessing Vulnerability: Estimating Potential Losses 3.5 Assessing Vulnerability: Estimating Potential Losses: Requirement §201.6©(2)(ii)(B): The plan should describe vulnerability in terms of an estimate of the potential dollar losses to vulnerable structures identified in paragraph (c)(2)(i)(A) of this section and a description of the methodology used to prepare the estimate. A. Potential Dollar Losses to Vulnerable Structures TABLE 4-3. EARTHQUAKE POTENTIAL LOSS INVENTORY County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 43 B. Methodology Used to Prepare Estimate Parcel Valuation Valuation of parcels within a hazard is based on improvement values only as collected by appraisers with the County of Santa Cruz assessor’s office. They don’t reflect sale value or replacement value. If a parcel intersected a hazard, the entire improvement value of that parcel was used. Population Census population blocks were reduced to center points. If a hazard intersected a center point, that population was counted. Estimates from the most recent California Geological Survey (CGS) presented by Rowshandel, M. Reichle, C. Wills, T. Cao, M. Petersen, D. Branum, and J. Davis in a paper titled Estimation of Future Earthquake Losses in California are limited to ground motion-induced losses to buildings only. In other words, the losses to other elements of the built environment, such as transportation, lifeline and communication facilities are not reported. Furthermore, the losses reported are only the direct economic losses due to building damage, which consist of capital stock loss and income loss. Indirect economic losses, representing the losses due to various forms of post-earthquake socioeconomic disruptions (such as employment and income, insurance and financial aids, construction, production and import-export of goods and services) are not included in the estimates reported. This is because of the higher level of uncertainty associated with the indirect losses, as compared to the direct losses. Therefore, it is expected that once the indirect building economic losses, the economic losses to non-building facilities, and the contributions of all earthquake hazards are taken into account, the estimated economic losses would be several times the numbers presented. 11 The analyses of the estimated losses are calculated in three forms: losses in dollars for individual counties, losses in dollars for individual census tracts, and Loss Ratios (LR) - the loss as a percentage of the building replacement value. Detailed results for all scenario earthquakes and for the statewide annual losses are available on the CGS website. 12 Among the 34 scenario earthquakes of the San Francisco Bay Area (SFBA), a repeat of the 1906 earthquake results in the largest economic loss for the ten SFBA counties. It would rupture four segments of the San Andreas fault and would cause approximately $54 billion economic loss due to building damage. A number of other earthquakes on the San Andreas fault, rupturing different combinations of these four segments are also feasible. Should one occur, it would result in an estimated loss ranging from a few billion dollars to $50 billion. Other potentially damaging earthquakes in the SFBA are: a magnitude 6.9 event rupturing the entire Hayward fault causing $23 billion in losses; and a magnitude 7.3 earthquake rupturing the entire Hayward fault and the Rodgers Creek fault causing $34 billion in losses. Estimates were calculated using the latest version of the HAZUS software package, Service Release 2 (SR2) for the estimation of the damage and economic loss. The earthquake hazard data, obtained from the scenario shake-maps or the Probabilistic Seismic Hazards Assessment (PSHA) maps, and the liquefaction data (for the case of annualized loss) were then analyzed and supplied into the HAZUS package. HAZUS-SR2 default data was used for the information on the built environment and the demographics. This information in HAZUS-SR2 is, for the County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 44 most part, derived from 1990 national census data. Using this process the most severe potential earthquake near Santa Cruz estimates a loss of over 2.2 billion dollars for the County. 4.3.6 Assessing Vulnerability: Analyzing Development Trends 3.6 Assessing Vulnerability: Analyzing Development Trends Requirement §201.6(c)(2)(ii)(C): The plan should describe vulnerability in terms of providing a general description of land uses and development trends within the community so that mitigation options can be considered in future land use decisions. Description of Land Uses & Development Trends The County of Santa Cruz has a number of compact urban communities as well as extensive areas of agricultural land and forested hillsides. A number of rural villages and towns are located throughout the County. As dictated by the 1978 Growth Management Ordinance 13, most new development has occurred within or adjacent to the urban services line (i.e., the boundary point for such infrastructure as water and sewage service). As with most communities, increased housing costs has resulted in the need to provide higher density housing. In Santa Cruz County, all development of this type occurs where urban services are available. Other development is mostly infill or reuse development, and development of existing rural residential properties. Growth management policies prevent development from occurring where hazards are present and, in most cases, require substantial setbacks from these hazards. Seismic safety standards are a requirement for all building permits. As infrastructure is repaired or replaced updated seismic safety standards are incorporated. 4.4.0 Mitigation Strategy 4.0 Mitigation Strategy – Requirement §201.6(c)(3): The plan shall include a mitigation strategy that provides the jurisdiction’s blueprint for reducing the potential losses identified in the risk assessment, based on existing authorities, policies, programs and resources, and its ability to expand on and improve these existing tools. The primary mitigation strategy to avoid or reduce damage from earthquake is continuation of design review and code enforcement to meet current seismic standards, including adequate geologic engineering and geotechnical monitoring protocols to insure structural integrity. Current policies that assist in meeting these standards include: Continued Enforcement of the Geologic Hazards Section of the County of Santa Cruz Code: Chapter 16.10 of the County Code requires the assessment of geologic hazards by the County Geologist and/or private engineering geologists for all new development projects. The geologic hazards identified through this assessment process are then mitigated by avoidance or through measures designed by civil engineers using the California Building Code. Continued rigorous enforcement of the California Building Standards with regards to seismicity including requiring engineering and liquefaction studies for all affected development. Continuing to encourage development adjacent to urban areas: By encouraging development in areas with urban services, the exposure of the population to areas County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 45 where earthquakes may damage roadways and other utilities is reduced. Encourage the State’s re-mapping of the County of Santa Cruz through the Seismic Hazards Zonation Program. Consider sharing the cost of the preparation of these new maps. 4.4.1 Mitigation Goals 4.1 Local Hazard Mitigation Goals – Requirement §201.6(c)(3)(i): The hazard mitigation strategy shall include a description of mitigation goals to reduce or avoid long-term vulnerabilities to the identified hazards. Earthquake Goals: Earthquake 1 - Avoid or reduce the potential for life loss, injury, property or economic damage to Santa Cruz from earthquakes. Earthquake 2-Encourage retrofitting and other mitigation activities that increase disaster resilience to earthquake. Earthquake 3 - Encourage further investigation and evaluation of faults in and near the County of Santa Cruz, and incorporate new information into the County of Santa Cruz site and building design requirements. 4.4.2 Identification and Analysis of Mitigation Actions 4.2 Identification and Analysis of Mitigation Actions – Requirement §201.6(c)(3)(ii): The mitigation strategy shall include a section that identifies and analyzes a comprehensive range of specific mitigation actions and projects being considered to reduce the effects of each hazard, with particular emphasis on new and existing buildings and infrastructure. Earthquake Mitigation Actions: Earthquake is one of the most significant threats to the County of Santa Cruz. The following actions are critical to the future safety of residents of the County of Santa Cruz: Coordinate preparedness efforts with other agencies. (A-1) Upgrade roadways, sewer, water and other infrastructure to withstand seismic shaking. (B-1) Promote seismic safety upgrade of all emergency use and critical structures. (C-1) Review all new and replacement critical structures to require that they be designed to standards of the California Building and County Geologic Hazards codes. (C-2) Train appropriate plan check staff on seismic requirements for structures. (C-3) Encourage zoning in geologically constrained areas that reflect the nature and extent of the hazard. (C-4) County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 46 Wildfires 5.3.0 Wildfire Risk Assessment 5.3.1 Identifying Wildfire Hazards 3.1 Identifying Hazards – Requirement §201.6(c)(2)(i): The risk assessment shall include a description of the type … of all natural hazards that can affect the jurisdiction. A wildland fire may be defined as any unwanted fire involving outdoor vegetation. This may be perceived as only occurring in forests, rangelands or agricultural fields, but it might also occur in vacant lots, highway medians, parks, golf courses and rural residential areas. The term Wildland Urban Interface (WUI) describes many of these areas. The nature of wildland fire has changed with incidents in the WUI. The potential for both life and property losses in the WUI is exponentially higher then non-populated wildlands. In addition, human influence has greatly increased the number and variety of potential sources of ignition. Wildland fires are influenced by three factors: fuel, weather and topography. Wildfire spread depends on the type of fuel involved (grass, brush and trees). Weather influences wildland fire behavior with factors such as wind, relative humidity, temperature, fuel moisture and possibly lightning. Several of these factors can modify the rate the fire will burn. Topography is the biggest influence on fire severity. In wildland fire, the priorities of the fire service are: Life Property Natural Resources Lower priorities are only protected when higher priorities have been confirmed safe. 5.3.2 Profiling Wildfire Hazard Events A. Location In Santa Cruz County there are numerous WUI areas and several areas designated as mutual threat zones. Mutual threat zones are defined as areas where a wildfire would threaten property within the Santa Cruz County Fire jurisdiction as well as property covered by another fire protection service. For major emergencies that require more resources than can be provided by a single agency, Santa Cruz County Fire, the University of California at Santa Cruz, other Fire Districts and the State of California (CALFIRE) have an extensive mutual aid and emergency coordination system. This system allows departments and districts to share personnel and equipment as needed to address and control emergencies. These geographic areas are described as non-State Responsibility Areas (SRA) in which any fire is considered a threat to adjacent SRA. These geographic areas are designated because of development that has occurred adjacent to vegetation that is considered significant. Other areas have been mapped as Wildfire Hazard Areas due to accumulations of wildfire County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 47 prone vegetation, steep and dry slopes and the presence of structures vulnerable to wildland fires. These areas are generally situated in the steeper higher elevations of the county. Most of these areas are along the border of Santa Clara County or in the Coastal ridges between Highway 9 and Highway 1. FIGURE 16. CRITICAL FIRE HAZARD AREAS WITHIN COUNTY OF SANTA CRUZ B. Extent: Magnitude or Severity The potential magnitude or severity of future fires could be predicted from experience gained from the recent fires of 2008/2009. In those fires, spotting exceeding 1 mile, torching of conifers, flame lengths exceeding 100’, area ignition and sheeting were all observed. In 2008, over 75 structures were destroyed on 3 fires alone. Similar fuels (Manzanita/Knobcone, Eucalyptus, chaparral, and mixed conifer forestland), topography and weather conditions are expected to be encountered in future fires creating a repeat of extreme fire behavior exhibited in recent large local fires. While normal weather conditions in the Santa Cruz Mountains can be categorized as cold and damp with extensive marine influence (fog), several times each year conditions are created where fuel moisture levels have been measured below 5% with temperatures above 90º, and north winds greater then 45 mph. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 48 C. PREVIOUS OCCURRENCES TABLE 5-1. PREVIOUS WILDFIRES WITHIN SANTA CRUZ COUNTY Fire Name Pine Mountain Newell Creek Newell Creek #2 Austrian Gulch Lincoln Hill Big Basin #7 Big Basin Rocha #2 Lexington Croy Fire Summit Fire Martin Fire Trabing Fire Lockheed Fire Loma Fire County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 Year 1948 1954 1959 1961 1962 1980 1982 1984 1985 2002 2008 2008 2008 2009 2009 Acres Burned 15,893 166 1,326 9,067 3,234 378 300 1,239 13,122 3,006 4,270 520 630 7,819 485 49 FIGURE 17. RECENT WILDFIRES IN COUNTY OF SANTA CRUZ During the past 2 fire seasons over 13,000 acres have burned in 5 major fires in Santa Cruz County. Each of these fires has burned structures and all have endangered life. Suppression costs alone for these fires have exceeded $60 million. The county endures over 200 wildland fires each year on the average but the past 2 years has brought this issue to the public’s attention. D. Probability of Future Events Given the continuation of 4 years of drought, it is likely that dry fuel conditions will remain. Areas identified as likely to have a wildland fire are spread out across the county. Most of these areas are associated with the higher dryer elevations with fuels consisting of Manzanita, chamise and knobcone pine. Even with the large acreages burned over the past two years, it was estimated that less then 10% of the higher hazard areas have been recently burned resulting in reduced fuel loads. The increasing trend of developing rural residences in these hazardous areas combined with continued recreational and transient uses of these remote locations have exacerbated the situation. A fire threat will always exist in the WUI. There will always be flammable vegetation, structures and human activities creating a situation where it is not “if” but “when” the next large fire occurs in the county. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 50 5.3.3 Assessing Wildfire Vulnerability: Overview 3.3 Assessing Vulnerability: Overview Requirement §201.6(c)(2)(ii): The risk assessment shall include a description of the jurisdiction’s vulnerability to the hazards described in paragraph (c)(2)(i) of this section. This description shall include an overall summary of each hazard and its impact on the community. A. Overall Summary of Vulnerability to Wildfires Santa Cruz County is ranked 9th among 413 western state counties for percentage of homes along the WUI and 14th in California for fire risk. 14 During the preparation of the countywide Community Wildfire Protection Plan (CWPP), numerous assets at risk were identified. These include thousands of residences, several schools including a State University, several youth camps, and numerous commercial facilities. There are 5 local public water systems with extensive infrastructure situated within high hazard areas. Three state highways and 3 major power transmission Rights of Way cross through vulnerable areas. Due to topography and limited access, both the protection plus potential reconstruction of these assets will be hampered. The impact of wildfire on a community is far-reaching (See Appendix O for Lockheed Fire Burn Severity). The most significant impacts would be loss of life, environmental damage and loss of property. Air quality is also a major issue, which can force the closure of schools and businesses as well as limit human activity. Damage to infrastructure such as culverts, roads and bridges can be difficult to locate and repair in a timely manner. During the rainy season, burned-over areas are subject to mud slides and debris torrents which can be exacerbated by infrastructure damage. Sedimentation due to winter rains can destroy fish habitats, which can have a catastrophic effect on the eco-system. 5.3.4 Assessing Vulnerability: Identifying Structures 3.4 Assessing Vulnerability: Identifying Structures – Requirement §201.6(c)(2)(ii)(A): The plan should describe vulnerability in terms of the types and numbers of existing and future buildings, infrastructure, and critical facilities located in the identified hazard area. A. Types and Numbers of Existing Buildings, Facilities and Infrastructure By definition WUI areas are adjacent to residential and open space areas. Only a few public buildings are immediately threatened by wildland fires. As part of this evaluation, Critical Fire Hazard Areas were assessed. Contained within these critical areas are over 10,000 structures including two schools and one fire station. 5.3.5 Assessing Vulnerability: Estimating Potential Losses 3.5 Assessing Vulnerability: Estimating Potential Losses – Requirement §201.6(c)(2)(ii)(B): The plan should describe vulnerability in terms of an estimate of the potential dollar losses to vulnerable structures identified in paragraph (c)(2)(i)(A) of this section and a description of the methodology used to prepare the estimate. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 51 CHAPTER 5 - WILDFIRES Potential Dollar Losses to Vulnerable Structures The Potential Loss Inventory for Santa Cruz County Unincorporated areas is attached. This summary indicates that over $1.5 billion of improvements are vulnerable to Wildfires in the Critical areas. See Table 5-2. TABLE 5-2. WILDFIRE POTENTIAL LOSS INVENTORY County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 52 5.3.6 Assessing Vulnerability: Analyzing Development Trends As demand for housing increases, residential construction has spread out into all of the different vegetative cover and topographic types throughout the county. Access to small rural residential clusters is governed by topography and ownership trends. Many clusters have only one access, which is usually limited to long stretches of narrow winding mountain roads. When these roads are blocked all access is blocked to these clusters. Santa Cruz County covers a large area made up of numerous remote areas with small rural residences. This makes patrolling and protecting the county from wildfire difficult. The county might be relatively small, but poor access and remoteness of many of the small rural residential clusters result in long response times for suppression equipment. Illegal camping, unpermitted home construction and a relatively large homeless population combined with a large population of urban residents living in a wildland environment have created a high risk of fire starts. Over the past 2 years this has resulted in several large (400 to 8,000 acre) wildland fires that have resulted in FMAG activation by FEMA. For future buildings, growth management policies prevent new development from occurring outside of the urban and rural services lines. 5.4.0 Mitigation Strategy 4.0 Mitigation Strategy: Requirement §201.6(c)(3): The plan shall include a mitigation strategy that provides the jurisdiction’s blueprint for reducing the potential losses identified the risk assessment, based on existing authorities, policies, programs and resources, and its ability to expand on and improve these existing tools. The various agencies responsible for protecting Santa Cruz County from losses due to Wildland Fires have implemented a number of mitigation programs over the years. They are as follows: Implementation and use of a Reverse 911 style community notification and warning system. Comprehensive mutual aid system for fire protection. Routine and frequent training by local and state fire jurisdictions. Annual Residential Defensible Space education and enforcement programs. Collaborative and cross jurisdiction Vegetation Management Programs including fuel reduction and shaded fuel break programs. Preparation of a countywide Community Wildfire Protection Plan (CWPP) using Federal Grant funding. Implementation of new County building codes addressing WUI related issues including building materials, construction requirements, water systems/supply and code enforcement. Promotion of built-in fire extinguishing, alarms and water systems per new fire code requirements. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 53 5.4.1 Mitigation Goals 4.1 Local Hazard Mitigation Goals – Requirement §201.6(c)(3)(i): Local Hazard Mitigation Goals – The hazard mitigation strategy shall include a description of mitigation goals to reduce or avoid long-term vulnerabilities to the identified hazards. Wildfire Goals: Wildfire 1 - Avoid or reduce the potential for injury, loss of life, property, and economic and environmental damage to Santa Cruz County from wildfire. Wildfire 2 - Collaborate with other local fire districts and departments in mutual aid fire protection efforts. 5.4.2 Identification and Analysis of Mitigation Actions 4.2 Identification and Analysis of Mitigation Actions – Requirement §201.6(c)(3)(ii): The mitigation strategy shall include a section that identifies and analyzes a comprehensive range of specific mitigation actions and projects being considered to reduce the effects of each hazard, with particular emphasis on new and existing building and infrastructure. Wildfire Mitigation Actions: Wildfire mitigation strategy includes the following actions: Strategy Establish and maintain cooperative fire protection and fire prevention agreements with other agencies. Early notification/warning of residents by technology based applications. Increased visibility and reduced response times with proper road and address markings. Enhanced support for interoperability communications systems with local, state and federal emergency services both inside and around the County. Reduction of fire risk in urban/wildland interface (WUI) through improved building materials and appropriate code enforcement including defensible space programs. Promotion of fuel reduction programs including strategic but environmentally compatible fuel break programs. Creation and maintenance of a proactive hazard abatement program including residential chipper and inspection programs. Maintain adequate Fire Suppression and Prevention staffing levels to meet the need of the county population and development trends. Implementation of additional Fire Prevention programs including school, institution and commercial inspections and educational programs. Creation and implementation of wildland hazard abatement programs. Implementation of education and code enforcement programs for proper road County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 Priority A A A A B B B B B B B 54 and residential address marking. Promotion of built-in fire extinguishing systems and fire alarm system. Land use planning to reduce incidence of human caused wildfires especially in very high fire hazard areas. Appropriate road and secondary access improvement and creation program. C C C Mitigation Action Table # A-12 A-10 A-13 A-14 B-3 B-4 Action Establish and maintain cooperative fire protection and fire prevention agreements with other agencies. Early notification/warning of residents by technology based applications. Increased visibility and reduced response times with proper road and address markings. Enhanced support for interoperability communications systems with local, state and federal emergency services both inside and around the County. Reduction of fire risk in urban/wildland interface (WUI) through improved building materials and appropriate code enforcement including defensible space programs, fuel reduction and residential chipper programs, and inspections. Maintain adequate Fire Suppression and Prevention staffing levels to meet the need of the county population and development trends. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 Hazard Multi-Hazard Responsible Fire, OES Timeline ongoing Multi-Hazard Fire, OES ongoing Multi-Hazard Fire ongoing Multi-Hazard Fire, OES ongoing Wildfire Fire, Planning ongoing Multi-Hazard Fire, OES ongoing 55 CHAPTER 6 — FLOODS AND ASSOCIATED COASTAL STORMS 6.3.0 Flood Risk Assessment 6.3.1 Identifying Flood Hazards 3.1 Identifying Hazards – Requirement §201.6(c)(2)(I): The risk assessment shall include a description of the type of all natural hazards that can affect the jurisdiction. Flooding and coastal storms present similar risks and are usually related types of hazards in the County of Santa Cruz. Coastal storms can cause increases in tidal elevations (called storm surge), wind speed, coastal erosion, and debris flows, as well as flooding. During a flood, excess water from rainfall or storm surge accumulates and overflows onto the banks, beaches, and adjacent floodplains. Floodplains are lowlands adjacent to rivers, lakes and oceans that are subject to recurring floods. Several factors determine the severity of floods, including rainfall intensity and duration, creek and storm drain system capacity, and the infiltration rate of the ground. A flood occurs when a waterway receives a discharge greater than its conveyance capacity. Floods may result from intense rainfall, localized drainage problems, tsunamis or failure of flood control or water supply structures such as levees, dams or reservoirs. Floodwaters can carry large objects downstream with a force strong enough to destroy stationary structures such as homes and bridges and break utility lines. Floodwaters also saturate materials and earth resulting in the instability, collapse and destruction of structures as well as the loss of human life. Floods usually occur in relation to precipitation. Flood severity is determined by the quantity and rate at which water enters the waterway, increasing volume and velocity of water flow. The rate of surface runoff, the major component to flood severity, is influenced by the topography of the region as well as the extent to which ground soil allows for infiltration in addition to the percent of impervious surfaces. It is important to note that a stream can crest long after the precipitation has stopped. As storms arrive onto land from the Pacific and rise over the mountains and ridges that border the eastern boundaries of the County, the air associated with those storms cools and that cooling results in large amounts of precipitation. The topography provides fairly steep and welldefined watershed areas to funnel the falling rain into runoff tributaries. Periods of very heavy rainfall are common throughout fall and winter months and the two rivers in the County, along with several creeks and streams, can rise to flood stage in a short period of time. Settlement and habitation in the County, from the historic Ohlone Indian camps through the founding of the Santa Cruz Mission in 1791, and subsequent logging communities throughout the 1800’s, tended to acknowledge the floodplain areas of the rivers and streams, building on the higher ground. However, as the population grew, particularly in the middle 1900’s, low lying areas near virtually every waterway were encroached upon for housing, business, or agricultural development. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 56 Climatologists point out that the period between 1920 and 1970, the years of most significant growth in Santa Cruz County, was a “dry cycle” for most of central California. Only one or two instances of serious winter weather in the 1950’s highlighted the consequence of development in low-lying areas. Over time, land that had previously been avoided was developed for both commercial and residential use in the floodplains of the San Lorenzo and Pajaro Rivers, Soquel and Aptos Creeks, and along the beaches. As a consequence, substantial portions of the City of Santa Cruz and the City of Watsonville have been flooded, houses and businesses in the San Lorenzo Valley have been damaged or destroyed by floodwaters, and there have been losses along Soquel Creek, Aptos Creek, and in beach areas on multiple occasions over the past half-century. 6.3.2 Profiling Flood Hazard Events 3.2 Profiling Hazards – Requirement §201.6(c)(2)(i): The risk assessment shall include a description of the location and extent of all natural hazards that can affect the jurisdiction. The plan shall include information on previous occurrences of hazard events and on the probability of future hazard events. A. Location Figure 18. Flood Zones within Santa Cruz County Most of the known floodplains in the United States have been mapped by FEMA, which County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 57 administers the National Flood Insurance Program (NFIP). Information about floodplains in the County of Santa Cruz can be found in FEMA’s most recent Flood Insurance Study (FIS) and on the Flood Insurance Rate Maps (FIRM). A small-scale version of all the FIRM panels for the County is provided above. Within the County of Santa Cruz there are numerous areas subject to flooding due to rivers, creeks or coastal storms. The two main rivers in the County that are subject to flooding are the Pajaro River and the San Lorenzo River. The Pajaro River and its floodplain runs through agricultural lands within the Pajaro Valley and, downstream, through downtown Watsonville. The San Lorenzo River runs through the heavily populated San Lorenzo Valley and into downtown Santa Cruz, where a 2002 levee project has significantly reduced the flood risk for downtown residents, merchants, and landowners. Other major creeks in Santa Cruz County adjacent to rural and urban development that are subject to flooding include Aptos Creek, Trout Creek, Valencia Creek, Salsipuedes Creek, Corralitos Creek, Soquel Creek, and their tributaries. The steepness of many of these creek canyons and the surrounding mountain areas contribute to the speed that flood water can accumulate and move resulting in relatively short warning times, increasing the hazard for those at risk. There are also many smaller creeks and tributaries throughout the County that are subject to flooding. Most of these are tributaries to the major creeks and rivers noted above. Areas of low-density development characterize the creeks along the North Coast of Santa Cruz County. Flooding of developed areas from storm surges is unlikely in this area, since development has occurred mainly on cliffs and inland of the coastal flood areas. While flooding is still a risk in these areas, there are no occurrences of repetitive loss (explained on pg. 59) from flooding along the North Coast. Coastal flooding along the heavily developed Monterey Bay coastline of Santa Cruz County may occur with the simultaneous occurrence of large waves and storm swells during the winter. Storm centers from the southwest direction produce the type of storm pattern most commonly responsible for the majority of severe coastline flooding. The strong winds combined with high tides that create storm surges are usually accompanied by heavy rains. When storms occur simultaneously with high tides, flood conditions, particularly flooding at the mouth of the Pajaro River and Aptos Creek, are exacerbated. B. Extent: Magnitude or Severity Flood hazard areas identified on the Flood Insurance Rate Map are identified as Special Flood Hazard Areas (SFHA). SFHA are defined as the area that will be inundated by the flood event having a 1-percent chance of being equaled or exceeded in any given year. The 1-percent annual chance flood is also referred to as the base flood or 100-year flood. SFHAs are labeled as Zone A, Zone AO, Zone AH, Zone AE, Zone A99, Zone AR, Zone V, and Zone VE. See Table 6-1 on the following page for an explanation of these zones. Moderate flood hazard areas, labeled Zone X (shaded), are the areas between the limits of the base flood and the 0.2percent-annual-chance (or 500-year) flood. The areas of minimal flood hazard, which are the areas outside the SFHA and higher than the elevation of the 0.2-percent-annual-chance flood, are labeled Zone C or Zone X (unshaded). County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 58 TABLE 6-1. FEMA Special Flood Hazard Area Zones and Definitions Flood Zone A AE AH AO AR A99 V VE X (Shaded on FIRM) X (not shaded on FIRM) Definition Areas subject to inundation by the 1-percent-annual-chance flood event. Base Flood Elevations or flood depths not determined. Areas subject to inundation by the 1-percent-annual chance flood event. Base Flood Elevations determined. Areas subject to inundation by 1-percent-annual-chance shallow flooding (usually areas of ponding) where average depths are between one and three feet. Base Flood Elevations determined. Areas subject to inundation by 1-percent-annual-chance shallow flooding (usually sheet flow on sloping terrain) where average depths are between one and three feet. Average flood depths determined. Areas that result from the decertification of a previously accredited flood protection system that is determined to be in the process of being restored to provide base flood protection Areas subject to inundation by the 1-percent-annual-chance flood event, but which will ultimately be protected upon completion of an underconstruction Federal flood protection system. These are areas of special flood hazard where enough progress has been made on the construction of a protection system, such as dikes, dams, and levees, to consider it complete for insurance rating purposes. Areas along coasts subject to inundation by the 1-percent-annual-chance flood event with additional hazards associated with storm-induced waves. Base Flood Elevations not determined. Areas subject to inundation by the 1-percent-annual-chance flood event with additional hazards due to storm-induced velocity wave action. Base Flood Elevations determined. Areas of 0.2-percent-annual-chance flood; areas of 1-percent-annualchance flood with average depths of less than 1 foot or with drainage areas less than 1 square mile; and areas protected by levees from 1percent-annual-chance flood. Areas determined to be outside the 0.2-percent-annual-chance flood. Repetitive Loss Properties FEMA records indicate that the County of Santa Cruz currently has 80 repetitive loss properties, which are NFIP-insured structures that have had at least two paid flood losses of more than $1,000 each in any 10-year period since 1978. Flood insurance claim payments on these properties alone total over $3.4 million dollars. Repetitive loss properties are concentrated in the San Lorenzo River corridor and the Aptos beach area (see map on next page; only 77 parcels have been shown as three could not be verified). The County of Santa Cruz is classified as a Category C Repetitive Loss Community under the Community Rating System (CRS). Category C Communities are those with more than 10 repetitive loss properties. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 59 FIGURE 19. REPETITIVE LOSS PARCELS WITHIN COUNTY OF SANTA CRUZ C. Previous Occurrences Flooding in Santa Cruz County has occurred in each of the primary drainages and will continue to do so in the future given the right set of meteorological conditions. Previous occurrences are well documented for all primary drainages with the exception of Aptos Creek, which is not gauged. The known occurrences are detailed below. Summary of Historical Floods in Santa Cruz County Major storms and associated flooding are known to have occurred during March 1899, December 1937, February 1940, November 1950, January 1952, December 1955, April 1958, January 1963, January 1967, January 1973, and January 1982. The December 1955 and January 1982 storms were the most severe in recent times. Below is a summary of the historic flooding for the major rivers, creeks, and beaches in Santa Cruz County. Aptos, Trout and Valencia Creeks Aptos Creek drainage basin is of small size and limited flood problems. It includes the drainage areas of Valencia Creek, Trout Creek, Bridge Creek and Mangles Gulch. Floods are known to have occurred in 1955, 1963 and 1982, however little information is available prior to 1955. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 60 During the four-day period ending December 22, 1955, heavy rains fell over the basin causing Aptos and Valencia Creeks to slightly exceed bank full stages at several points in the lower basin. Agricultural damage was primarily due to scour and erosion of first shelf lowlands planted to pasture, a few orchard crops and idle croplands. The peak flow was measured at 3,500 cfs and approximately 140 acres were inundated, of which 20 acres were cropland. Non-cropland damages were generally very minor, consisting of eroded private roads and washed out culverts. County roads and bridges experienced relatively heavy damages at the Valencia Road crossing. The bridge on Aptos Creek just below the confluence of Aptos and Valencia Creeks sustained a washout of cribbing endangering the bridge structure. Four homes along Moosehead Drive, downstream from the village of Aptos, experienced flooding. The Southern Pacific Railroad sustained minor damage due to undermining of the roadbed at Aptos, which resulted in a seven-day interruption of rail service. The local telephone company sustained minor damages to the undermining of facilities in the floodplain (United States Army Corps of Engineers [USACE], Floodplain Information, Aptos, Trout, and Valencia Creeks, 1973). The January 1982 flood had a peak flow of 3,950 cfs and corresponded to a 40-year recurrence interval based upon stream gauge data in Aptos Creek. Heavy damage occurred from this storm. At least seven homes along Moosehead and Spreckels Drive between Highway 1 and the Spreckels Drive Bridge suffered major damage (Department of Earth Sciences, 1982). Further downstream damage resulted to major portions of two streets paralleling Aptos Creek. Pajaro River, Salsipuedes Creek, and Corralitos Creek During December 21 through 24, 1955, and April 2 through 4, 1958, the Pajaro Valley experienced flooding. These floods are the two largest on record for the Pajaro River. The associated discharges for these events were 24,000 cfs and 23,500 cfs, respectively, at the Chittenden gauge (USACE, 1963). The estimated recurrence intervals for floods of these magnitudes are 27 years and 26 years, respectively. In comparison, the estimated discharge at Chittenden for a 100-year flood is 43,000 cfs. (FEMA Flood Insurance Study March 2, 2006). In the December 1955 flood, the Pajaro River was maintained within the levees in the Watsonville area, but the levees were breached 2.1 miles upstream of the confluence with Salsipuedes Creek (USACE, 1963). Although no lives were lost, 972 people were evacuated and $1.12 million damage incurred. Included in these costs were monies spent to repair levees damaged by erosion. Additional levee repairs were required because of the April 1958 flood; however, no other significant damage resulted (USACE, 1963). Significant flooding along Corralitos and Salsipuedes Creeks also occurred in December 1955 and April 1958. Peak discharges for Corralitos Creek at Green Valley Road have been estimated from high-water elevations (USACE, 1956). The estimated discharges for the 1955 and 1958 floods are 3,620 cfs and 2,680 cfs, which correspond to recurrence intervals of 12 and 7 years, respectively. The overflow of Corralitos Creek upstream of the leveed section on Salsipuedes Creek flooded 29 blocks within the City of Watsonville during the December 1955 flood (USACE, 1963). The Pajaro Valley experienced only minor damage from the January 1982 flood. (FEMA Flood Insurance Study March 2, 2006). County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 61 In 1995, a major flood event breached the Pajaro River levees and the Town of Pajaro was flooded. San Lorenzo River The San Lorenzo River basin is the largest drainage basin contained entirely within the County. Few records exist of flooding in the San Lorenzo Basin (outside of the City limits) prior to 1940. However damaging storms are known to have occurred in 1940, 1955, 1958, and 1982. In January 1862, within the City limits, land was consumed and buildings along the riverbanks were destroyed. January 1890 saw the largest river level recorded to this date. In January 1895, a storm caused flooding of basement, yards and lots in the City of Santa Cruz. In March 1907, floodwaters were higher than previous floods. February 1940 and 1941, saw continued episodes of flooding. December 1955 was the highest historic flood along the San Lorenzo River and had a peak discharge of 30,400 cfs, which equates to approximately a 30-year recurrence interval. The most intensive rainfall fell during a four-day period from December 21-24. In the central part of the basin, known as the Ben Lomond area, the San Lorenzo River exceeded bank full stage. Local reports indicate previous maximum stages of record were exceeded along Kings, Boulder, Two Bar, and Zayante Creeks in the upper basin. Overflows occurred from the headwaters to the mouth, resulting in the maximum flood of record. The heavy rains and overflows loosened and scoured out large trees, and floated them downstream where they became lodged at channel points of constriction, impounding flow, causing extremely severe local flooding. The numerous log jams and other channel obstructions diverted the high velocity flows, causing the streams to change from the normal alignment, undercut and scour out numerous bridges, road fills, channel dams and private developments. It is estimated that at least 388 acres were flooded. Seven people (5 within the Santa Cruz City limits, 2 outside) lost their lives as a result of the flood. It is estimated that 390 people outside the City limits were displaced by the floodwaters. Numerous houses, roads, parks, and commercial properties were damaged or destroyed in the Boulder Creek, Ben Lomond, Felton and Paradise Park areas. (USACE, 1973) The April 1958 flood was minor in comparison to the 1955 flood, but still saw erosion, creek bank failures and damage and loss of houses. The magnitude of the January 1982 flood was similar to the December 1955 flood and had a peak discharge of 19,700 cfs. Damage upstream of the City of Santa Cruz was extensive. The damage was most extensive in the area between the upstream limits of Felton and in the areas of Paradise Park, Gold Gulch and Felton Grove. In the Felton Grove area, floodwaters in the overbanks reached 3 to 7 feet and inundated 50 homes and cabins. An additional 60-70 homes were flooded between Felton and Ben Lomond. It is estimated that the 1982 flood had a recurrence interval along the San Lorenzo River of County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 62 approximately 30 years. (FEMA Flood Insurance Study March 2, 2006). Soquel Creek Storms of flood-producing magnitude occurred during March 1899, December 1937, February 1940, January 1943, November 1950, January 1952, December 1955, April 1958, October 1962, January 1963, January 1967, and January 1982. The December 1955 storm is the most severe storm of recent times, its seventy-two hour rainfall interval was equivalent to about 35 percent of the normal annual rainfall. During the flood of 1955, a major logjam occurred at the Soquel Avenue Bridge, causing a severe backwater condition. In Soquel, eight city blocks were inundated displacing 359 persons (USACE, 1956). Just upstream of the confluence with Hinkley Creek, floodwaters in the overbanks reached depths of five to six feet. The peak flow for Soquel Creek at the Soquel gauge indicated a peak flow of 15,800 cfs, which is a recurrence interval of 70 years (FEMA Flood Insurance Study March 2, 2006). During the 1982 flood, the Soquel Creek basin experienced major flooding in the vicinity of the Soquel Avenue Bridge. A massive logjam diverted flow down the main street of the town of Soquel. The floodwaters rose rapidly along Soquel Creek and caused major damage to two mobile home parks adjacent to the stream. The estimated peak flow was 9,700 cfs, which equates to an estimated recurrence interval of approximately 16 years. Beach / Coastal Flooding Flooding along the Pacific coast of Santa Cruz is typically associated with the simultaneous occurrence of high tides, large waves, and storm swells during the winter. As a result, ocean front development has not been compatible with the natural instability of the shoreline and intense winter weather conditions. (FEMA FIS, March 2, 2006). Significant storms, with associated damage, strike the Monterey Bay communities with a frequency of one large storm every 3 to 4 years (Ott Water Engineers, Inc., 1984). The most severe storms on record to hit the California coast occurred in 1978 and 1983 when high water levels were accompanied by very large storm waves (FEMA FIS, March 2, 2006). In 1978, a series of storms emanated from a more southerly direction, than normal. Consequently, some of the more protected beaches were damaged. Jetties and breakwater barriers were overtopped and in some cases undermined. Direct wave damage occurred to many beachfront homes and seawalls, especially in the more populated beachfront areas such as at Seacliff Beach and Rio Del Mar Beach. (FEMA FIS, March 2, 2006). In 1983 a similar storm hit the Santa Cruz Coast. During this storm a new 3,500-foot seawall was destroyed and in Seacliff Beach 19 of 21 homes were significantly damaged when the existing riprap protection was overtopped. (FEMA FIS, March 2, 2006). The Pajaro Dunes area of the County that is fronted by dunes has also been subject to severe damage to structures as well as rapid beach retreat in 1968, 1969, 1978 and also County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 63 in 1983. (FEMA FIS, March 2, 2006). D. Probability of Future Events Significant storms and associated damage from flooding strike the Monterey Bay communities with a frequency of one large storm every three to four years. A 100-year flood has a one percent probability of occurring in any given year and while considered to be a severe flood, it still has a reasonable possibility of regular occurrence. For the purposes of the protection of property, life and safety, floods of other magnitudes and occurrence intervals should also be considered in mitigation efforts. Floods are gauged by their cresting elevation, the area of inundation or damages and either the size of the event or the probability of occurrence. The size and depth of the floodplain area is computed using mathematical models of precipitation, slope, runoff, soil type and crosssection. Flood depths are calculated at intervals along a stream or channel corridor and then mapped and interpolated between sections. This results in the floodplain map. The probability of occurrence is expressed in a percentage of the chance of a flood of a specific extent occurring in any given year. The most widely adopted design and regulatory standard for floods in the United States is the 1-percent annual chance flood, and this is the standard formally adopted by FEMA. The 1-percent annual flood is also commonly referred to as the “100-year flood,” leading to the misconception that it should occur only once every 100 years. In fact, a 100-year flood may occur in any year, regardless of the time that has passed since the last one. It is the probability that smaller floods occur more often than larger floods that compels the percentage. TABLE 6-2. FLOOD PROBABILITY TERMS Flood Occurrence Intervals 10 years 50 years 100 years 500 years Percent Chance of Occurrence Annually 10.0% 2.0% 1.0% 0.2% 6..3.3 Assessing Flood Vulnerability: Overview 3.3 Assessing Vulnerability: Overview – Requirement §201.6(c)(2)(ii): The risk assessment shall include a description of the jurisdiction’s vulnerability to the hazards described in paragraph (c)(2)(i) of this section. This description shall include an overall summary of each hazard and its impact on the community. A. Overall Summary of Flood Vulnerability Riverine flooding is a risk for many parts of the communities of Boulder Creek, Ben Lomond, Brookdale, Felton, Zayante, Paradise Park, unincorporated Santa Cruz, unincorporated Scotts Valley, Live Oak, Soquel, Rio Del Mar, Aptos, and unincorporated Watsonville. Coastal flooding is a risk for many homes along Live Oak, Aptos, Seascape, and unincorporated Watsonville beaches. Many homes, apartments, hotels, shops, and critical facilities have been built in these County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 64 areas to accommodate resident and tourist needs. Properly protecting these structures from flooding is essential to preventing loss of human life and protecting the local economy. Under a widespread heavy rain scenario (accumulation of .30 inches of rain per hour or more), severe flooding is likely in low-lying areas within a basin. Based on the 100 year flood plain (FEMA Zone A), 11% of the developed parcels (8,359) 5% of roads (103 miles), 25% of the sheriff’s facilities (3), 30% of the fire stations (7), 9% of schools (16) and approximately 15% of the churches (32) are located within or intersected by the 100 year flood plain. Summary of Flood Protection Measures and Future Vulnerability Flood protection measures implemented in the unincorporated areas of Santa Cruz County have included nonstructural and structural measures. The nonstructural measures include floodplain zoning ordinances that regulate building within the floodplain as well as protection of riparian areas that further limits impacts of flooding on structures. Structural measures implemented in the County have been limited primarily to the Pajaro Valley. Although dozens of houses in the flood prone areas of the County have been elevated above the 100-year flood or wave run-up elevation over the past decade, areas previously inundated by flooding will continue to do so in the future, with potentially substantial impacts to property, lives and infrastructure. Flows in excess of approximately 10,000 cfs caused flooding on the lower Pajaro River before completion of the Federal levee project (USACE, 1963). After the floods of 1938 and 1941, the USACE designed levees for the Pajaro River and Salsipuedes Creek. Levees were completed along the Pajaro River by the USACE in 1949. Levees along the north bank begin just upstream of the mouth at the Pacific Ocean and continue to approximately River Mile 11.8 (Murphy Road); levees along the south bank begin just upstream of the mouth and continue to River Mile 10.6. The levees increased the capacity of the Pajaro River to 22,000 cfs downstream of Salsipuedes Creek, equivalent to a 25-year flood. In the same year, levee construction on Salsipuedes Creek from the confluence with the Pajaro River to River mile 2.5 on the west bank to River Mile 1.7 on the east bank was also completed (USACE, 1963). The addition of the levees increased the capacity of Salsipuedes Creek to 10,000 cfs (USACE, 1963). In 1963, the USACE performed additional studies and recommended that the levees along the Pajaro River and along Salsipuedes and Corralitos Creeks be modified to provide additional protection (USACE, 1963). Construction was authorized in the Flood Control Act of 1966 and the project proceeded to the advanced stages of design, but local support in Watsonville was withdrawn and the project was placed in a deferred status (USACE, 1978; and USACE, 1974). However, in recent years, studies on the Pajaro River levees have indicated that they may fail under a roughly 8-year event (approximate flow of 18,000 cfs). The County of Santa Cruz and the U.S. Army Corps of Engineers are currently working together to come up with a solution to enhance the levees and increase the level of flood protection. See Figure 20 on the next page for Pajaro River Flood Risk map. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 65 FIGURE 20. PAJARO RIVER FLOOD RISK MAP No major flood control projects have been constructed in the Aptos Creek, Soquel Creek, or the Santa Cruz County portion of the San Lorenzo River basins. Local interests have provided noncontinuous bank protection constructed of various materials including concrete, timber, and riprap. A multiple-purpose reservoir on Soquel Creek, approximately 5 miles upstream from Monterey Bay, was found to be economically justified, but has not been implemented. A major flood control project, which includes levees and channel improvements, was constructed on the San Lorenzo River. These improvements, however, are located within the Santa Cruz City limits and not in the unincorporated portion of the county. Residents and municipalities of northern Monterey Bay have spent hundreds of thousands of dollars on flood protection measures to prevent coastal flood damage. Permanent structures such as seawalls, boulder-sized riprap, timber, and concrete bulkheads have been installed. Severe storms in January of 1983 overtopped many of the structures. Protection varied by site. At Seacliff State Beach, repeated storms have destroyed reconstruction efforts, while at New Brighton State Beach, damage was minor. At Seacliff State Beach in January 1983, high waves associated with high tides overtopped a rock rubble mound to cause major damage to 19 of 21 homes. Of the 9.5 miles of northern Monterey Bay coastline, over half is protected by seawalls or riprap. After the major flood in December 1955, a flood-control project was constructed by the USACE to provide protection against a flow of 53,000 cfs at the mouth of the San Lorenzo River. The flood-control project included improvements on the San Lorenzo River as well as Branciforte Creek. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 66 On the San Lorenzo River, the project extended from the Southern Pacific Railroad (SPRR) bridge near the mouth to the city’s concrete weir diversion works. Between the SPRR bridge and the State Highway 1 bridge, the project included levees, channel improvements, and bank protections; upstream of State Highway 1, only channel improvements were made. The modified channel was wider with a lower invert than the natural channel. Channel improvements were designed to provide 3 feet of freeboard and to carry 53,000 cfs downstream of the confluence with Branciforte Creek and 46,800 cfs between the confluence and the State Highway 1 bridge. On Branciforte Creek, a rectangular concrete channel was constructed and extended upstream 1 mile from the confluence with the San Lorenzo River at the Soquel Avenue bridge. Nonstructural measures employed by the City of Santa Cruz include a logjam removal procedure and flood plain zoning ordinances. The zoning ordinances regulate development in the flood plain areas (City of Santa Cruz, 1975). Impact of Hazards Flooding in the various river basins impact public health and safety, critical facilities and infrastructure, as well as the community’s economy. When floods hit the community, as shown by past history, public health and safety issues (including loss of life and property as well as the overall health of the community) can be widespread. Recognition of these hazards has led the County of Santa Cruz to work with FEMA, in recent years, to assist property owners in funding elevation of homes above the base flood elevation (Felton Grove) and to develop a plan to improve levee safety (Pajaro River). Additionally, the County of Santa Cruz has improved rain and stream gauging in the San Lorenzo River, Soquel Creek, Corralitos Creek and Pajaro River watersheds. The improved gauging includes real-time monitoring of rainfall and stream levels that are monitored 24 hours a day during storm event. See Watershed Flood Monitoring Table 6-3, on the following page. This monitoring is coordinated with the County Public Works Department, the County Emergency Operations Center, the National Weather Service in Monterey, NOAA, and the USGS. In the Pajaro River watershed, monitoring coordination also includes the Santa Clara Water District, and the counties of San Benito and Monterey. Close coordination has allowed an alert system to be developed through the use of a reverse 911 system. This system may not save fixed structures, but it can save lives. Coordination with other agencies has also helped to time releases from reservoirs (Santa Clara Water District), so that releases do not coincide with peak flows. Following is a table of Santa Cruz County Stream / River Flood Stages that has been developed to assist flood control staff in their monitoring of flooding. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 67 TABLE 6-3 SANTA CRUZ COUNTY STREAM/RIVER FLOOD STAGE Stream & Location Datum 0= San Lorenzo R. Big Trees, Felton Soquel Creek Bridge St. 227.0’ NGVD 21.4’ NGVD Corralitos Cr Green Valley Rd. 89.4’ NGVD Today’s Levels Salsipuedes Cr Hwy 129 Flood Watch Stage 10.0’ Flood Monitor Stage 14.0’ 8.0’ 11.5’ 9.0’ 9.0’ 25.0’ 32.0’ Pajaro River @ Chittenden 81.9’ NGVD 23.0’ 25.0’ Pajaro River @ Main St 0’ NGVD 23.0’ 27.5’ Initial Overflow Areas Felton Grove, Gold Gulch, and Paradise Park Heart of Soquel, Old Mill Mobile Home Park, Areas west of Porter St. Orchard Park Subdivision, College Rd. Flood Watch & Monitor Stages at the same level due to fast rising water 2.4-mi down-stream from Corralitos Cr., Orchard Park, College Rd (Drew Lake) Top of levee at 37.5’ Area along channel extending 2.5-miles upstream from confluence of Pajaro R. & Salsipuedes Cr. Top of levee at 34.5’ Flood Warning Stage 18.0’ 14.5’ 11.5’ 34.5’ 32.0’ 31.0’ LARC (computer voice msg - stream levels) SLR @ Big Trees: 335-9365 County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 68 NON-LEVEED STREAMS Flood Watch Stage: The Stage at which current or developing conditions pose a threat of flooding but it is NOT certain or imminent. Flood Monitor Stage: The Stage at which initial action must be taken by concerned interests (livestock warning, removal of equipment from lowest overflow areas, or simply general surveillance of the situation). This level may produce overbank flows sufficient to cause minor flooding of low-lying lands and local roads. Flood Warning Stage: The Stage at which overbank flows are of sufficient magnitude to cause considerable inundation of land and roads and/or threat of significant hazard to life and property. LEVEED STREAMS Flood Monitor Stage: The Stage at which patrol of flood control project levees by the responsible levee maintaining agency becomes mandatory, or the Stage at which flow occurs into bypass areas from project overflow weirs. Project Flood Stage: The Stage at which the flow in a flood control project is at maximum design capacity (U.S. Corps of Engineers "Project Flood Plain"). At this level there is a minimum freeboard of 3 feet to the top of levees. Danger Stage: The Stage at which the flow in a flood control project is greater than maximum design capacity and where there is extreme danger with threat of significant hazard to life and property in the event of levee failure. This is generally 1 foot above project flood stage. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 69 6.3.4 Assessing Flood Vulnerability: Identifying Structures 3.4 Assessing Vulnerability: Identifying Structures – Requirement §201.6(c)(2)(ii)(A): The plan should describe vulnerability in terms of the types and numbers of existing and future buildings, infrastructure, and critical facilities located in the identified hazard area. Types and Numbers of Existing buildings, Facilities and Infrastructure Table 6.4 on the following page identifies the number of parcels that intersect the flood plain. All of the structures on those parcels have been included as potential losses in that table. However, a more detailed analysis, recently completed for the FEMA Biennial Report, assessed whether specific habitable structures on those parcels were located within the floodplain. This data shows that there are over 2,000 1-4 unit residential structures and over 200 other habitable structures in the flood hazard areas of Santa Cruz County. Approximately 3,200 permanent year-round Santa Cruz County residents live flood hazard areas. 6.3.5 Assessing Vulnerability: Estimating Potential Losses 3.5 Assessing Vulnerability: Estimating Potential Losses – Requirement §201.6(c)(2)(ii)(B): The plan should describe vulnerability in terms of an estimate of the potential dollar losses to vulnerable structures identified in paragraph (c)(2)(i)(A) of this section and a description of the methodology used to prepare the estimate. A. Potential Dollar Losses to Vulnerable Structures Approximately 6400 parcels lie within the flood zone areas with the majority of these parcels categorized as residential. Within the residential areas, there are over 5700 structures. The population in the flood zone is 15,110. The potential loss in residential areas alone tops $683 million. When all types of land use are considered, the potential loss is over $841 million. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 70 TABLE 6-4. FLOOD POTENTIAL LOSS INVENTORY B. Methodology Used to Prepare Estimate Parcel Valuation Valuations of parcels within a hazard area are based on improvement values only as collected by appraisers with the Santa Cruz County Assessor’s Office. They do not reflect sale value or replacement value. If a parcel intersected a hazard, the entire improvement value of that parcel was used. Population Census population blocks were reduced to center points. If a hazard intersected a center point, that population was counted. Flood Analysis Since FEMA flood data is mapped on the federal level, the data is somewhat coarse in horizontal accuracy. The data is a rough estimate of expected flood elevations and loss areas. Estimating flood losses is an established process. If a “100 year” flood occurred in our county, County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 71 meaning that the flood has a 1% chance of occurring in any given year, it would impact approximately 8400 structures to various degrees. This was determined by intersecting the county’s database of structures with the FEMA-developed maps of the 100-year floodplain. Structures within the floodplain vary in construction, size and materials, ranging from singlefamily homes to multi-family to commercial. 6.3.6 Assessing Vulnerability: Analyzing Development Trends 3.6 Assessing Vulnerability: Analyzing Development Trends – Requirement §201.6(c)(2)(ii)(C): The plan should describe vulnerability in terms of providing a general description of land uses and development trends within the community so that mitigation options can be considered in future land use decisions. A. Description of Land-Uses and Development Trends The County of Santa Cruz has a number of compact urban communities as well as extensive areas of agricultural land and forested hillsides. A number of rural villages and towns are located throughout the County. As mandated by the 1978 Growth Management Ordinance, most new development has occurred within or adjacent to the urban services line (i.e., the boundary point for such infrastructure as water and sewage service). As with most communities, increased housing costs have resulted in the need to provide higher density housing. In Santa Cruz County, all development of this type occurs where urban services are available. Other development is mostly infill or reuse development, and development of existing rural residential properties. Growth Management policies prevent development from occurring where hazards are present and, in most cases, require substantial setbacks from these hazards. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 72 6.4.0 Mitigation Strategy 4.0 Mitigation Strategy: Requirement §201.6(c)(3): The plan shall include a mitigation strategy that provides the jurisdiction’s blueprint for reducing the potential losses identified in the risk assessment, based on existing authorities, policies, programs and resources, and its ability to expand on and improve these existing tools. Programs Currently in Effect The County of Santa Cruz currently addresses land use within the floodplain in the General Plan as well as actively enforcing related building, zoning, and resource planning codes, and other land use regulations concerning development within the 100-year floodplain. The 2007 California Building Code has several new enforceable provisions for development in flood hazard areas, which should be incorporated into County building and resource planning codes. The County participates in a number of ongoing mitigation actions to avoid or reduce the threats of flood. Actions include: The County is the lead agency in an early warning flood forecasting system for evacuation of areas susceptible to flooding. Continual improvements to the early warning system are being planned and implemented, especially as they relate to the Upper Pajaro watershed, the San Lorenzo watershed and in the severely burned areas of recent fires. Regulations on development and alteration of flood plains, stream channels and protective barriers that accommodate overflow are in place. Encouragement of property owners, potential buyers and residents living in floodplains and coastal inundation areas to participate in the National Flood Insurance Program (NFIP). Rehabilitation of remote culverts and storm drainage systems to reduce flooding caused by inadequate storm drainage. Annual Flood Control Maintenance on the Pajaro River by the Public Works Department. This work is required by the U.S. Army Corps of Engineers and consists primarily of managing in-stream riparian vegetation to encourage geomorphic form and function. The vegetation management plan is identified in the Final EIR for the Pajaro River and Salsipuedes and Corralitos Creeks and requires vegetated buffer zones to be generally maintained at 10-feet at the toe of the levees and 5-feet along the wetted edge of the river. The vegetation management is required in order for winter flows not to exceed the design capacity of the Pajaro River levees. Future Plans The County will take the necessary steps to apply for and be accepted into the Community Rating System (CRS). The CRS is a voluntary incentive program that is part of the National Flood Insurance Program (NFIP). The program recognizes and encourages community floodplain management activities that exceed the minimum NFIP requirements (FEMA 2002). As a result, flood insurance premium rates will be discounted to reflect the reduced flood risk resulting from community actions meeting the following three goals of the CRS: County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 73 Reduce flood losses Facilitate accurate insurance rating Promote awareness of flood insurance For communities participating in the CRS, flood insurance premium rates are discounted in increments of 5 percent, with the lowest class communities receiving the highest discount. For example, a Class One community would receive a 45 percent premium discount, and a Class Nine community would receive a 5 percent discount. A Class Ten community, which is the current designation for Santa Cruz County, does not participate in the CRS and receives no discount. The CRS classes for local communities are based on 18 creditable activities organized under the following four categories: Public Information Mapping and Regulations Flood Damage Reduction Flood Preparedness Currently, approximately 1,000 communities nationwide receive flood insurance premium discounts based on implementation of local mitigation, outreach, and educational activities that go well beyond minimum NFIP requirements. Assigning Priority to Mitigation Actions Priority levels have been assigned to each of the mitigation actions. Highest priority has been given to those actions that are relatively inexpensive to implement, are required as part of other programs (e.g. NFIP), and/or will reduce the costs of flood damage to the County and the costs of flood insurance to the public. Project Feasibility It should be noted that there are many items that are infeasible at this time due to current County budget cuts and recent and possible future layoffs. These items include installing gauges on Aptos and Valencia Creeks, expansion of drainage system monitoring, and construction of the Soquel Creek Reservoir. In addition to limited funding for implementing these programs, there is very little staff time to devote to applying for financial assistance. As the economic climate improves, these programs can be integrated into future iterations of this report. 6.4.1 Mitigation Goals 4.1 Local Hazard Mitigation Goals – Requirement §201.6(c)(3)(i): The hazard mitigation strategy shall include a description of mitigation goals to reduce or avoid long-term vulnerabilities to the identified hazards. The County of Santa Cruz has developed several flood hazard mitigation goals to create a more flood-resistant community. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 74 Flood Goals Flood 1 Avoid or reduce the potential for life loss, property and economic damage from flooding Flood 2 Enhance emergency management tools Flood 3 Protect critical facilities, schools, and utilities from flooding Flood 4 Promote public awareness of flood hazards, mitigation measures and flood insurance Flood 5 Preserve open space in the flood hazard area 6.4.2 Identification and Analysis of Mitigation Actions 4.2 Identification and Analysis of Mitigation Actions – Requirement §201.6(c)(3)(ii): The mitigation strategy shall include a section that identifies and analyzes a comprehensive range of specific mitigation actions and projects being considered to reduce the effects of each hazard, with particular emphasis on new and existing buildings and infrastructure. Flood Mitigation Actions High Priority Items 1. The County will create a policy interpretation for calculating “Substantial Improvement” more effectively in the floodplain (A-2). 2. The County will apply for and participate in the Community Rating System to improve floodplain management and reduce insurance costs for residents. Steps required include: (A-3) a. Conduct analyses of Repetitive Loss Areas and create action plans for each area detailing the necessary steps to prevent future losses. b. Prepare for, schedule, and complete a Community Assistance Visit (CAV) with FEMA staff. c. Establish clear criteria for requiring Elevation Certificates. d. Create and maintain an online database of Elevation Certificates. 3. The County shall evaluate the effectiveness of current policies and ordinances designed to limit storm water runoff and flooding and, if needed, recommend revisions to improve the effectiveness of these policies and codes. (A-4) 4. The County shall evaluate the effectiveness of current drainage plan requirements to ensure that storm water runoff from impervious surfaces does not contribute to flooding and, if needed, revise permit conditions of approval to better achieve this result. (A-5) 5. The County shall review and, if needed, revise its California Environmental Quality Act (CEQA) Initial Study checklist to ensure that storm water runoff is fully considered and mitigated to the extent practicable. (B-2) County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 75 6. The County shall develop a “Storm Water Facilities Master Plan” for Flood Control Districts 5 & 6, which include portions of Live Oak, Soquel, Aptos, Seacliff and Rio Del Mar areas. This will include an inventory of existing facilities, development of hydraulic and hydrologic modeling of these facilities, development of a prioritized Capital Improvement Program list, hydromodification analysis and development of generic best management practices and design standards. (A-6) Lower Priority Items 1. The County will seek funding to develop, adopt, update and revise the Geologic Hazards Ordinance. The ordinance will incorporate new flood hazard area development standards that exceed the minimum requirements of FEMA. This will require significant staff time and adoption of the new ordinance by the Board of Supervisors. At least one public hearing will be required. (B-5) 2. The County will pursue elevation of structures, in which a house is raised above the level of the 100-year flood. Elevation is a relatively simple mitigation for flood hazards, involving the use of hydraulic jacks to elevate the house, much in the same manner as jacking a car to change a tire. However, it is expensive, since it requires technical studies, the use of special equipment, professional experience, insurance and materials. Once elevated, a new cast in place concrete foundation is built, and supporting walls and beams installed. The house is then lowered onto the new base, perhaps as much as 10’ higher than it previously sat. Requiring elevation of existing structures will be facilitated by the policy interpretation described under High Priority Action Item 1. (B-6) Acquisition, or buying out a homeowner, is an alternative method of mitigating flood hazards, but has been proven too expensive in Santa Cruz County due to high real estate prices. Relocation is similarly prohibitive, since it involves finding a similar parcel, purchasing it, and moving the house to that location. Vacant lots are expensive and hard to find in Santa Cruz County. 3. The County will continue to maintain drainage system infrastructure. The Department of Public Works Road Operations crews will seek funding to expand its existing inspection and maintenance of the drainage systems within the County-maintained roads during the rainy season. Problem spots with more recurrent flooding occurrences will be monitored frequently to remove any drainage system blockage and minimize flooding. Drainage Operations crews maintain drainage channels as well as County-maintained drainage systems outside the County’s right of way. (C-9) In preparation for the winter rains, starting in July or as allowed by permitting agencies, Drainage Operations crews will obtain permits to inspect and clear vegetation, remove silt and sand bars if needed in drainage channels, creeks and rivers. Clean up will continue during the year and specifically after rainstorms to remove debris, logs and large items from the channels. Areas in flood plains will be monitored frequently during rainstorms to prevent flooding as much as possible. Countywide logjam removal programs will be active year round and specifically before the rainy season and after rainstorms. 4. The County will continue to enforce requirements for on-site retention of storm water runoff from impervious surfaces for all new development in the Ground Water Recharge Zone and the Water Supply Watershed zone on site. These Zones cover over 50 percent of the County where the soils have high permeability rates. The County will continue to require on-site County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 76 percolation system design as well as best management practices to increase storm water retention and decrease flash floods, although it will be equally important that downstream capacity be maintained to insure that the storm drain system can handle peak flows. (B-7) 5. The County will seek grants to develop public education materials both in print- and webbased formats. The County will also maximize opportunities to work collaboratively with community groups, non-governmental organizations and the local media. (C-10) 6. Through its application of the Geologic Hazards Ordinance and Open Space Preservation policies, the County will regulate development in flood zones to optimize preservation of open space. (C-11) 7. County staff will continue to limit development and monitor conditions of development and grading permits as well as illegal unpermitted activities to prevent sedimentation in natural channels and wetlands. (C-12) Public Works Design Criteria continue to require runoff retention system details to be submitted with permit applications. Erosion and sediment control measures will be monitored in the field, evaluated, and improved upon when deficiencies are identified. Implementation and Evaluation A Flood Mitigation Planning Committee will be created and will consist of the Floodplain Manager and key Planning Department, Office of Emergency Services, and Department of Public Works staff members. The County will convene regular meetings of the Committee to assess and evaluate progress on the goals and action items in the Plan. Additionally, the Committee will work with responsible agencies to promote the goals and action items in their annual budgets and work programs. The Committee will prepare an Annual Evaluation Report and distribute the report to the Board of Supervisors, the Community Rating System Coordinator for inclusion in the annual Community Rating System Report, the local news media and the public. References This flood plan was prepared by County of Santa Cruz planning and engineering staff with input from the County Department of Public Works and the County Office of Emergency Services. Preparation of this Chapter of the LHMP included a review of the following documents for information and to define the County’s needs, goals, and plans: 2002 County of Santa Cruz Flood Hazard Mitigation Plan County of Santa Cruz Flood Insurance Study County of Santa Cruz Geographic Information Systems data County of Santa Cruz census data County of Santa Cruz 2007-2008 Biennial Report County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 77 CHAPTER 7 – DROUGHT 7.3.0 Drought Risk Assessment 7.3.1 Identifying Drought Hazards 3.1 Identifying Hazards – Requirement §201.6(c)(2)(i): The risk assessment shall include a description of the type … of all natural hazards that can affect the jurisdiction. A drought is a period of dry weather that persists long enough to cause serious problems such as crop damage and/or water supply shortages. Droughts may not be predictable, but they should be expected. They occur with some regularity and varying levels of severity. The magnitude and duration of a drought is something that can be predicted based on historical records and should be taken into account in water resources planning. In recent history, Santa Cruz County experienced 3 drought periods: 1976-77, 1987-1992, and most recently in 200709. It is expected that the effects of climate change will result in more severe droughts of longer duration. Water supply in Santa Cruz County is provided by a number of independent water agencies, as shown in the table below. Fifty-seven percent of the County population is served by the two largest jurisdictions, the cities of Santa Cruz and Watsonville, with substantial parts of their service areas outside of the city limits. 37% of the Santa Cruz customers (32,500 people) and 20% of the Watsonville customers (12,000 people) are outside the city limits. Almost all of the jurisdictions are experiencing some kind of water supply shortfall, as indicated, either due to overdraft of the groundwater basin from which they derive supply, inadequate supply during a drought, or inadequate facilities to meet current demands. 46% of County population is served by water agencies that get more than 50% of their supply from surface water. It is those sources that are most susceptible to drought impacts. TABLE 7-1. WATER SUPPLIERS WITHIN COUNTY OF SANTA CRUZ Water Supplier Connections Santa Cruz City Water Dept. Watsonville City Water Dept Soquel Creek Water District San Lorenzo Valley (SLVWD) - Northern SLVWD Southern SLVWD-Felton Scotts Valley Water District Central Water District Lompico Creek Water County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 Pop. 25,000 15,000 15,000 95,000 63,700 49,000 5,300 785 1,300 3,600 800 500 16,500 2,500 4,000 11,300 2,700 1,300 Water Current Use Ground Surface Shortfall? (acrefeet/yr) 11,800 4% 96% Drought 9,300 89% 11% Overdraft Overdraft 5,400 100% Drought 1,500 40% 60% Overdraft 400 100% 455 100% Drought Overdraft 1,700 100% OK 600 100% 70 20% 80% Drought 78 District Big Basin Water Company Mount Hermon Association Forest Lakes Mutual Water Company 130 Smaller Water Systems (5-199 connections)* Individual Users* Pajaro Agriculture 580 530 1,500 1,400 240 250 15% 100% 330 900 140 100% 5000 8000 14,000 20,800 3500 6000 48,000 89,355 95% 95% 100% 85% ? Overdraft Facilities OK 81,725 284,600 *Values are Estimates 5% 5% OK Overdraft Each water supply agency that serves more than 3000 connections is required to prepare and maintain an urban water management plan, which among other things, outlines the susceptibility of the supply to drought. Those plans have been completed by all the large agencies. Groundwater supplies are not as susceptible to drought impact as groundwater represents a large reserve that can be pumped more heavily during a short- term drought period. However, almost all of the groundwater basins in Santa Cruz County are in overdraft and current average pumping levels cannot be sustained on a long-term basis. Water conservation is a key strategy of all county water agencies, and during the recent drought all agencies sought consumption reductions of 15-20% through voluntary or mandatory measures, as indicated below. TABLE 7-2. WATER CONSERVATION TARGETS Measure System-wide Reduction Target Mandatory conservation No watering between 9:00 a.m. and 6:00 p.m. Outdoor watering limited to 2 days per week * 15 minute time limits on automatic overhead spray irrigation systems Sweeping of paved areas instead of washing down/ Prohibit washing of any outdoor impervious surface Car washing must be done with a bucket and hose with shut-off nozzle Water upon request only in public restaurants and linen service in hotels and motels by request only Display by restaurants and hotels of water conservation signs. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 City of Santa Cruz 15% X between 10:005:00 San Watsonville Lorenzo Valley 20% X Soquel Creek Scotts Valley 15% 10% Voluntary Voluntary between 10:00-5:00 X X X X X X X X X X X X X X X X X X X X X X X 79 Swimming pools may not be initially filled, or drained and refilled All hoses must have shut-off nozzles Waste of water due to broken or defective plumbing, sprinklers and watering/irrigation systems is prohibited. Bulk water sales not available for construction use. X X X X X X X X X X X X Santa Cruz County has no direct authority over the entities that provide water supply to county residents. The two largest suppliers are governed by the city councils elected by city residents. Independently elected Boards govern the other public entities. The California Public Utilities Commission oversees the privately owned water systems to some extent. All water systems are governed by state and federal safe drinking water regulations. The larger systems with more than 200 connections are regulated directly by the California Department of Public Health. The County serves as an agent of the state, ensuring compliance with the state regulations for 130 small water systems with 5-199 connections. The County also permits individual water systems to serve new homes in rural areas. Typically these are on wells. Although well yield standards for new development are conservative, it is possible that individual wells and older wells serving small water systems may experience diminished yield or go dry during an extended drought. The County has no ongoing oversight of water use for individual water systems after the initial development permit is approved. The City of Santa Cruz, which supplies water for 36% of the County’s population, is the county water agency that is most susceptible to drought impacts, given that only about 4% of its supply comes from groundwater. Santa Cruz relies on surface water in coastal streams and the San Lorenzo River for most of its annual water supply needs. The yield of these sources in any given year is directly related to the amount of rainfall received and runoff generated during the winter season. Water stored in Loch Lomond Reservoir is used mainly in the summer and fall seasons when the flows in the coast and river sources decline and additional supply is needed to meet dry season demands. The problem of supply reliability stems primarily from two factors: the wide range in the yield of surface water sources from year to year and limited storage capacity. In normal and wet years when rainfall and runoff are abundant, base flows in the coast and river sources are restored by winter rains, and Loch Lomond Reservoir is typically replenished to full capacity with runoff from the Newell Creek watershed. The water system, however, is highly vulnerable to shortage in drought years when the San Lorenzo River and coast stream sources run low. In single dry years, the system relies more heavily on water stored in Loch Lomond to satisfy demand, which draws down the reservoir level lower than usual and depletes available storage. In multi-year or critical drought conditions, the combination of very low surface flows in the coast and river sources and depleted storage in Loch Lomond reservoir reduces available supply to a level which cannot support average dry season demands. Compounding the situation is the need to reserve some amount of storage in Loch Lomond in the event drought conditions continue into the following County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 80 year. The highest priorities of the City during a drought are domestic uses, sanitation, and fire protection. 7.3.2 Profiling Drought Hazard Events 3.2 Profiling Hazards – Requirement §201.6(c)(2)(i): The risk assessment shall include a description of the location and extent of all natural hazards that can affect the jurisdiction. The plan shall include information on previous occurrences of hazard events and on the probability of future hazard events. A. Location The areas of the county most susceptible to impacts of drought are those areas served primarily by surface water sources: the City of Santa Cruz and the San Lorenzo Valley. The Santa Cruz water system includes the entire City as well as outlying areas as far away as parts of Capitola and unincorporated areas of the north coast and the DeLaveaga area. A map of the water system coverage area is shown in Figure 21 and Figure 22 on the following pages. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 81 FIGURE 21. WATER SERVICE AREA CITY OF SANTA CRUZ County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 82 FIGURE 22. MAP OF WATER AGENCIES COVERAGE AREA IN SANTA CRUZ COUNTY B. Extent: Magnitude or Severity There is a significant difference in severity between a single dry year and multiple dry years in Santa Cruz. As can be seen from the history of drought in Santa Cruz in Figure 23 taken from the City of Santa Cruz 2005 Urban Water Management Plan (UWMP), 15 there have been at least five multi-year dry periods since 1921. Single Dry Year: The total water supply estimated to be available to the City in single dry years is 3,800 million gallons (mg) or about 12% less than is available in normal years. Table 7-3, taken from the UWMP, shows that there would be a relatively small supply deficit in single dry years under current demand conditions, which will increase as demand increases over time. TABLE 7-3. SINGLE DRY YEAR SUPPLY AND DEMAND ASSESSMENT (MILLION GALLONS) Supply Totals Demand Totals Difference 2005 3,800 3,900 (100) 2010 3,800 3,952 (152) 2015 3,800 4,154 (354) 2020 3,800 4,345 (545) 2025 3,800 n/a -- 2030 3,800 n/a -- Multiple Dry Years: In an extreme two-year drought similar to the 1976-77 event, the estimated water supply available to the City in the second year of that event is 2,700 mg or about 37% less on an annual basis than is available in normal water years. Table 7-4 shows that there County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 83 would be a severe water supply shortage under current demand conditions, which will grow worse as demand increases over time. The shortfall is also expressed in Table 7-4 as the percent of supply available to meet demand during the peak season between April and October, since this is the period of year that would be most affected by a supply shortage. Under such conditions, the water system is barely able to meet half of normal requirements of the water service area. TABLE 7-4. MULTIPLE DRY YEAR SUPPLY AND DEMAND ASSESSMENT (MILLION GALLONS) Supply Totals Demand Totals Difference Peak Season Deficit 2005 2,700 3,900 (1,200) 46% 2010 2,700 3,952 (1,252) 47% 2015 2,700 4,154 (1,454) 52% 2020 2,700 4,345 (1,645) 56% 2025 2,700 n/a -- 2030 2,700 n/a -- C. Previous Occurrences The City of Santa Cruz, which is the service area most impacted by drought, uses a water year classification system as an index of water supply conditions for operations studies, to forecast river flows, and to communicate its water supply status to the public. The system is based on total annual runoff in the San Lorenzo River. Under this classification system, the water year (October 1- September 30) is designated as one of four types: wet, normal, dry, or critically dry, depending on the total annual river discharge (Figure 23). Figure 23 also shows the total annual runoff for the San Lorenzo River over the 84-year period from 1921 to 2009 and the classification for each water year 16. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 84 FIGURE 23. TOTAL ANNUAL RUNOFF IN THE SAN LORENZO RIVER (ACRE FEET) The graph illustrates the dramatic variation in discharge from year to year. Average runoff during this period is about 93,000 acre-feet or 30 billion gallons 17. The least amount of runoff, 9,500 acre-feet, occurred in the drought of 1977. The maximum recorded discharge was over 280,000 acre-feet in 1983, one of the wettest years on record in California. Over this relatively brief hydrologic record, about two-thirds of all years are classified as wet or normal and the other one-third is classified as dry or critically dry. From 1995 to 2006, water conditions were mostly normal or wet. 2007 was the first year of the state’s current 3-year drought. During this period, 2007 was classified as critically dry, 2009 was classified as dry, and 2008 was just slightly wetter than the dry classification. Water use restrictions were imposed during 2007 and 2009 in the city of Santa Cruz, and throughout other parts of the county during all 3 years. 2010 may also be a dry year. D. Probability of Future Events One approach to evaluating probability of future events focuses on the magnitude of the worstcase drought, because it is the degree of shortfall that determines what actions the community would have to take and the resulting hardships the public would face. It should also take into account, though, the chance of that event occurring before a solution is achieved. The amount of time that elapses before new supply can be developed is an important consideration because it also has a bearing on the degree of risk faced by water customers; the longer the delay, the greater the risk. As with the threat of other natural hazards County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 85 like a flood or an earthquake, the probability of a severe drought in any one-year may be comfortably low. For instance, the drought on record of 1977 has a recurrence interval of 1 in 59 years. This means the probability of such an event is 1/59 or 0.017, which is the same as a 1.7% chance of occurrence in any one year. But the percent probability of occurrence, or chance, of a shortage occurring over a longer time frame is considerably higher, which changes the perception of the significance of risk. The following Table 7-5 presents the chance of various shortfalls occurring within the existing City of Santa Cruz water system over a specified period of time: TABLE 7-5. RELATIONSHIP OF WATER SHORTAGES WITH VARIOUS RECURRENCE INTERVALS TO PROBABILITY OF OCCURRENCE OVER TIME Shortage Magnitude Recurrence Interval 10% or more 20% or more 30% or more 7 in 59 4 in 59 1 in 59 Percent Probability of Occurrence over: 5 years 47 30 8 10 years 72 51 16 20 years 92 76 29 30 years 98 88 40 To address the estimated shortages, construction of a desalination plant has been recommended. If the recommended desalination plant could be built in the next five years, the odds are about even of experiencing a moderate water shortage over this time and there is only an 8 percent chance of experiencing a critical drought like the 1977 event between now and then. On the other hand, if the project were delayed or rejected, and the earliest another project realistically could be commissioned was twenty years out, the chance of experiencing a moderate shortage over this time rises to over 90 percent and nearly 30 percent for a critical drought, which exposes the community to a much greater risk. 18 The expected effects of climate change will also increase the risk of drought. Numerous climate models have been run with various predictions for the Santa Cruz County area. 19 Although it is unclear whether the average amount of rainfall will increase, it is apparent that the timing and intensity of rainfall will change, which will lead to more severe extended droughts. More intense rainfall will contribute to relatively diminished groundwater storage, which will reduce groundwater storage and dry season stream baseflows, which will have adverse impacts on water supply. The projected increase in temperatures will also lead to an increase in water demand for irrigation, particularly in the inland parts of the county that are less influenced by coastal fog. The county water agencies are currently pursuing more detailed assessments, which will help to better quantify the expected impacts of climate change. 7.3.3 Assessing Vulnerability: Overview 3.3 Assessing Vulnerability: Overview – Requirement §201.6(c)(2)(ii): The risk assessment shall include a description of the jurisdiction’s vulnerability to the hazards described in paragraph (c)(2)(i) of this section. This description shall include an overall summary of each hazard and its impact on the community. A. Overall Summary of Vulnerability to Drought Vulnerability to drought varies with the different water agencies and their sources. Agencies County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 86 with a greater reliance on surface water are more vulnerable than those that rely entirely on groundwater. County water agencies are considering plans now to provide more interties among jurisdictions to be able to exchange water in the event of an emergency or shortage. The City of Santa Cruz System is the most vulnerable to a drought. The City does not presently have access to outside water sources should local supply be inadequate to meet demands during dry years. As a closed, isolated system, the City is highly vulnerable to shortage in drought years when the San Lorenzo River and coast sources run low. In single dry years, the system relies more heavily on water stored in Loch Lomond to satisfy demand, which draws down the reservoir level lower than usual and depletes available stored reserves. In multi-year or critical drought conditions, the combination of very low surface flows in the coast and river sources and depleted storage in Loch Lomond reservoir reduces available supply to a level which cannot support average dry season demands. If water shortages as a result of drought do occur, rationing would go into effect. Conservation programs, curtailment programs, and plans to increase water supply are all components that will decrease the vulnerability of the community to drought. 7.3.4 Assessing Vulnerability: Identifying Structures 3.4 Assessing Vulnerability: Identifying Structures – Requirement §201.6(c)(2)(ii)(A): The plan should describe vulnerability in terms of the types and numbers of existing and future buildings, infrastructure, and critical facilities located in the identified hazard area. A. Types and Numbers of Existing Buildings, Facilities and Infrastructure Structures and facilities are not vulnerable to drought. Physical losses would probably be limited to public and private landscaping. However, the impacts to the landscaping, which occur as the result of severe drought conditions, also increase the risk of wildfire and subsequent damage to structures as a result. 7.3.5 Assessing Vulnerability: Estimating Potential Losses 3.5 Assessing Vulnerability: Estimating Potential Losses – Requirement §201.6(c)(2)(ii)(B): The plan should describe vulnerability in terms of an estimate of the potential dollar losses to vulnerable structures identified in paragraph (c)(2)(i)(A) of this section and a description of the methodology used to prepare the estimate. A. Potential Dollar Losses to Vulnerable Structures While structures are not at risk, significant losses may occur as a result of severe rationing during a water shortage. One of the County’s major industries is tourism. The vulnerability to drought (or more specifically water shortages as a result of drought) reaches its peak during the summer tourism season. Restaurants, hotels, amusement parks and other tourist serving businesses would all be at risk of closing or severe restrictions during a critical drought. This is critical to funding ongoing County services because of the County’s reliance on the Transient Occupancy Tax (TOT). Other industries such as agriculture, food processing, contractors, landscapers, nurseries, golf courses, public landscaping and school grounds would all experience losses, and other water dependent businesses would suffer economic damages. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 87 These economic losses have not been calculated. B. Methodology Used to Prepare Estimate While potential economic losses have been considered, they have not been calculated; therefore, there is no loss estimate. 7.3.6 Assessing Vulnerability: Analyzing Development Trends 3.6 Assessing Vulnerability: Analyzing Development Trends – Requirement §201.6( c)(2)(ii)(C): The plan should describe vulnerability in terms of providing a general description of land uses and development trends within the community so that mitigation options can be considered in future land use decisions. A. Description of Land-Uses & Development Trends The greater Santa Cruz area is a compact urban area surrounded by mountains, greenbelt and the Pacific Ocean. The sizes of the water service areas are generally fixed by the city limits and the County’s urban services line. Water service areas for all jurisdictions have generally remained constant over time due to policies limiting water main extensions to unserved areas. The only extensions of service or agency boundaries have involved incorporating an existing developed area into a larger district, which has better capabilities for providing reliable water service. Accordingly, any growth and redevelopment that does happen going forward is expected to be concentrated within the confines of the existing service area boundaries. Within the City of Santa Cruz, the San Lorenzo Valley, and other areas only a relatively small amount of land remains undeveloped. Because of the relative scarcity of raw buildable land, the majority of future growth in the area is likely to be achieved through redevelopment, remodeling, infill, and increased density on underutilized land, along with new construction on the little amount of vacant land remaining. In other words, the service areas are relatively fixed 20 and not growing outward. There has not been a residential subdivision in rural areas of the county since the adoption of Measure J, the County’s growth management plan, in the late 1970’s. Both the City of Watsonville and the City of Santa Cruz have also established urban growth boundaries. The housing elements of the County and the cities have recently been updated to address the required regional fair share housing needs established by AMBAG. These documents set forth goals and objectives for housing production, rehabilitation, and conservation. The plans identify generally where sites are available for housing to be built and describe programs to facilitate new housing opportunities, but this does not necessarily mean such housing actually will be constructed. The City of Santa Cruz Water system currently serves approximately 95,000 people and is anticipated to grow to 100,000 by 2030 21. The city system has additional capacity of 300-400 million gallons per year (MGY) during normal years. By 2025 or 2030 (depending on growth rates), this surplus is expected to be fully utilized by additional growth within the service area, including planned University growth. Although this growth in demand can be accommodated during normal years (7 years out of 10), the growth in demand will exacerbate the current shortfall during dry years. In a worst case scenario, (second drought year with year 2030 County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 88 demand after 0.8% yearly growth) total demand would exceed supply by 38% (1656 MGY). Most of this deficit is attributed to existing users (72%), followed by University growth (6%) and other new demand in the city service area. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 89 7.4.0 Mitigation Strategy 4.0 Mitigation Strategy: Requirement §201.6(c)(3): The plan shall include a mitigation strategy that provides the jurisdiction’s blueprint for reducing the potential losses identified in the risk assessment, based on existing authorities, policies, programs and resources, and its ability to expand on and improve these existing tools. Water agencies have developed Urban Water Management Plans, Integrated Water Plans, and groundwater management plans that include elements to overcome potential drought impacts. The agencies are now working together to update and implement the 2005 Santa Cruz Integrated Regional Water Management Plan, which will coordinate and prioritize the actions of all the agencies to address water resource needs including development of additional sustainable supplies and improved management of existing supplies to reduce drought impacts for individual agencies. 7.4.1 Mitigation Goals 4.1 Local Hazard Mitigation Goals – Requirement §201.6(c)(3)(i): The hazard mitigation strategy shall include a description of mitigation goals to reduce or avoid long-term vulnerabilities to the identified hazards. Given that the County does not have any direct authority over water supply, the County is limited in the actions it can take to mitigate drought, other than to support the efforts of various water supply entities to address drought. Goals to reduce the impacts of drought are contained in the various plans described above. For example, the goals of the City of Santa Cruz 2005 Urban Water Management Plan and the Integrated Water Plan (IWP) include: Drought Goals: Drought –1 Reduce near-term drought shortages Drought –2 Provide a reliable supply that meets long-term needs while insuring protection of public health and safety 7.4.2 Identification and Analysis of Mitigation Actions 4.2 Identification and Analysis of Mitigation Actions – Requirement §201.6(c)(3)(ii): The mitigation strategy shall include a section that identifies and analyzes a comprehensive range of specific mitigation actions and projects being considered to reduce the effects of each hazard, with particular emphasis on new and existing buildings and infrastructure. Drought Mitigation Actions: Implement water conservation to maximize the use of existing water resources. (A-7) Support the development of additional water supplies (A-8) Promote more effective use of groundwater storage through increased groundwater recharge and conjunctive use among agencies. (A-9) County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 90 Promote drought planning by the 130 small water systems under County jurisdiction. (C-13) Water Conservation. Both the state water law and the County’s General Plan call for a strong emphasis on water conservation and elimination of water waste to stretch existing sources, minimize the need for new water sources, and protect the environment. Most of the water agencies have strong conservation programs, which are supported by the County. The County will be considering additional measures to provide tougher regulations and an overdraft impact fee, which would be paid by new development in overdrafted basins, to fund reduction of water use by existing users. Additional Water Supply. The City of Santa Cruz and Soquel Creek Water District are pursuing the construction of a desalination plant which would consist of a seawater intake system using an existing abandoned wastewater outfall, building a new desalination plant with an initial capacity of 2.5 mgd, installing the associated pipelines and pumping stations for delivering treated water to the Bay Street Reservoir, and conveying seawater concentrate to the City’s wastewater facilities where it would be blended with municipal wastewater flows and disposed via the deep ocean outfall. The purpose of this initial phase of desalination capacity is for drought protection. Accordingly, the desalination plant would only be used by the City intermittently during the dry seasons of dry and critically dry years when existing supplies fall short. It would be used at other times by Soquel Creek Water District to allow reduction of groundwater pumping and increased groundwater storage. Groundwater Storage, Recharge and Conjunctive Use. County staff are supporting the efforts of the water agencies to evaluate more possibilities for water exchanges and conjunctive use options which would have the potential to utilize more surface water during wet periods, increase use of recycled water, increase groundwater storage, increase stream baseflow, and potentially make more groundwater available to surface water users during drought periods. County staff is also pursuing various methods to increase groundwater recharge through projects and policies to restore and maintain storm water infiltration. Drought Planning for Small Water Systems. Staff will review existing information and state requirements and determine if there would be a significant benefit to require additional drought planning by small water systems. Some systems may have already developed plans, and some may be limited by lack of technical expertise and financial capability. The costs and benefits of such a program will be considered and discussed with state regulators. At a minimum, systems could be sent a mailer encouraging them to plan ahead. B. Actions and Projects to Reduce the Effects of Hazards on New Buildings Drought does not present a direct hazard to buildings. C. Actions & Projects to Reduce Effects of Hazards on Existing Buildings Drought does not present a direct hazard to buildings. Proper maintenance and weed abatement including removal of dead landscape vegetation adjacent to buildings will reduce the threat of structure fire during dry years. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 91 7.4.3 Implementation of Mitigation Actions 4.3 Implementation of Mitigation Actions – Requirement §201.6©(3)(iii): The mitigation strategy section shall include an action plan describing how the actions identified in section ©(3)(ii) will be prioritized, implemented, and administered by the local jurisdiction. Prioritization shall include a special emphasis on the extent to which benefits are maximized according to a cost benefit review of the proposed projects and their assorted costs. A. Discussion of Process and Criteria Used to Prioritize Mitigation Actions Individual water supply master plans, groundwater management plans, and urban water management plans were developed with a process for technical review and public review, which resulted in a prioritization of recommendations for each water supply agency. The Santa Cruz Integrated Regional Water Management Plan compiled the recommended projects from the various plans prepared by the water supply agencies. Projects were prioritized based on the ability to meet multiple Plan objectives. B. Implementation and Administration of Mitigation Actions Implementation of agency plans is in progress. Proposition 50 funds were secured to implement 15 priority projects in the IRWMP: Abandoned Well Destruction Conjunctive Use Plan for Lower San Lorenzo Watershed Aptos Drainage Master Plan Storm water Pollution Prevention Groundwater Recharge Projects New Brighton Sewer Relocation Desalination Project Intake Evaluation Polo Grounds Well and Treatment Plant Polo Grounds Monitoring Well Davenport Drinking Water Treatment Upgrade Watsonville Slough Wetland Restoration Integrated Watershed Restoration Program Scotts Valley Recycled Water Main Extensions Coordinated Monitoring Update of the Santa Cruz Integrated Regional Water Management In addition, County staff are preparing a package of water conservation measures to take to the Board of Supervisors for adoption, including water efficient landscaping, prohibition on inefficient use of water, groundwater overdraft impact fee, and an update of the requirement for the retrofit of water efficient toilets and showerheads upon property transfer. Additional measures to encourage drought planning among small water systems will be considered. Emphasis on the Use of Cost–Benefit Review The County did not use a formal cost benefit analysis. Costs were carefully considered when determining goals and objectives but there was not an emphasis on cost benefit review to maximize benefits. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 92 CHAPTER 8 — TSUNAMI 8.3.0 Tsunami Risk Assessment 8.3.1 Identifying Tsunami Hazards 3.1 Identifying Hazards – Requirement § 201.6(c)(2)(i): The risk assessment shall include a description of the type of all natural hazards that can affect the jurisdiction. A tsunami is a series of waves generated by an impulsive disturbance in a large body of water such as an ocean or large lake. Tsunamis are produced when movement occurs on faults in the ocean floor, usually during very large earthquakes. Sudden vertical movement of the ocean or lake floor by a fault, landslide or similar movement displaces the overlying water, creating a wave that travels outward from the source. The waves can travel across oceans and maintain enough energy to damage distant shorelines. The hazard posed by tsunamis came to the attention of the world during the 2004 Indian Ocean tsunami that killed as many as 300,000 people who lived more than a thousand miles from the source of the earthquake. An earthquake anywhere in the Pacific Ocean can cause tsunamis around the entire Pacific basin, including offshore of Santa Cruz County. Since the Pacific Rim is highly seismically active, tsunamis are not uncommon, but historically have been only a few meters in height. Correspondingly there has been minimal damage and loss of life in Santa Cruz from tsunamis during recorded history. However, the historic record is short, and may not reflect the true tsunami hazard to the County. The potential outcome of a tsunami could be significant damage and loss of life. 8.3.2 Profiling Tsunami Hazard Events 3.2 Profiling Hazards – Requirement §201.6(c)(2)(i): The risk assessment shall include a description of the location and extent of all natural hazards that can affect the jurisdiction. The plan shall include information on previous occurrences of hazard events and on the probability of future hazard events. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 93 FIGURE 24. TSUNAMI INUNDATION MAP A. Location The County of Santa Cruz is located on Monterey Bay. Several active and potentially active earthquake faults are located within or near the County of Santa Cruz. An earthquake occurring in or near any of the nearby faults could result in local source tsunamis from submarine landsliding in Monterey Bay. Additionally, distinct source tsunamis from the Cascadia Subduction Zone to the north, or Teletsunamis from elsewhere in the Pacific Ocean are also capable of causing significant destruction. B. Extent: Magnitude or Severity A local source tsunami generated by an earthquake on any of the faults affecting the County of Santa Cruz could arrive just minutes after the initial shock. The lack of warning time from such a nearby event would result in higher causalities than if it were a distant tsunami where the Tsunami Warning System for the Pacific Ocean could warn threatened coastal areas in time for evacuation. Past experience has not resulted in extensive damage from tsunamis, but proximity to faults does create the possibility as a result of future quakes. C. Previous Occurrences Tsunamis have affected the County of Santa Cruz several times in recorded history. The first County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 94 recorded tsunami was a teletsunami that initiated from an earthquake near Japan on June 15, 1896. In Japan, the death toll was approximately 20,000 people, but in Santa Cruz the tsunami was only a meter and a half high and there is little record of damage. A more significant tsunami occurred on April 1, 1946 when a magnitude 7.8 earthquake in the Aleutian Islands produced a 115-foot wave, which destroyed the Scotch Cap lighthouse killing five Coast Guardsmen. It was 56 feet high in Hawaii killing 173 people. The wave was observed all along the west coast. In Santa Cruz County, a man drowned and minor damage was done by 10-foot waves. It should be noted that scientific observations place the 1946 Tsunami run up at 1.5 meters. Santa Cruz County was hit by a similar sized tsunami generated by the Good Friday Earthquake of March 27, 1964. Reports vary indicating heights between 1.5 meters and 3.3 meters. After the Loma Prieta Earthquake, a small tsunami, or seiche, was observed at the Santa Cruz Harbor. California is at risk from both local and distant source tsunamis. Eighty-two possible or confirmed tsunamis have been observed or recorded in California during historic times. Most of these events were small and only detected by tide gages. Eleven were large enough to cause damage and four events resulted in deaths. D. Probability of Future Events Tsunami Hazard Anticipating the extent of future tsunami hazard is difficult because the historic record is limited, as is our understanding of the source mechanisms and influence of offshore geometry on the impact of tsunami in Santa Cruz County. Studies have recently been undertaken by Richard K. Eisner, Jose C. Borrero and Costas E. Synolakis through the Governor’s Office of Emergency Services and the Department of Civil Engineering at the University of Southern California, Los Angeles. In Inundation Maps for the State of California, the authors clarify that the results are based on worst-case scenario events and the maps are only to be used for emergency preparedness and evacuation planning. Pre1994 inundation computations underestimated inundation height. Newer inundation models are now capable of modeling extreme events more accurately. These new inundation models (known as MOST) permit quantitative evaluation of inundation from nearfield tsunamis, provided accurate regional tectonic models and high-resolution bathymetry exist. Even using state of the art inundation prediction tools, California presents unique challenges in assessing tsunami hazards because: There is an extremely limited historic record of tsunamis in the state. In California there are no known records before the 19th century. Some paleo-seismic investigations have revealed evidence of pre-historic tsunamis, but not in the County of Santa Cruz. Most of the geologic work in the state has concentrated on identifying the risks associated with onshore faults and there is scant available information on offshore faults or landslide and slump scars suggestive of past submarine mass failures. Earlier estimates of tsunami hazards relied almost entirely on farfield sources and used pre-1980’s technology, creating the impression among planners and the public that the tsunami hazard was small. Nearshore seismic events may trigger tsunamis arriving within less than 20 minutes from peroration, allowing little time for evacuation. Shorelines and shoreline platforms vary significantly throughout the state, which County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 95 modify tsunami run up and the corresponding potential damage. 8.3.3 Assessing Tsunami Vulnerability: Overview 3.3 Assessing Vulnerability: Overview – Requirement §201.6(c)(2)(ii): The risk assessment shall include a description of the jurisdiction’s vulnerability to the hazards described in paragraph (c)(2)(i) of this section. This description shall include an overall summary of each hazard and its impact on the community. A. Overall Summary of Vulnerability to Tsunami There are two primary types of tsunami vulnerability in Santa Cruz County. The first is a teletsunami or distant source tsunami from elsewhere in the Pacific Ocean. This type of tsunami is capable of causing significant destruction in Santa Cruz County. However, this type of tsunami would usually allow time for the Tsunami Warning System for the Pacific Ocean to warn threatened coastal areas in time for evacuation. The more vulnerable risk to the County of Santa Cruz is a tsunami generated as the result of an earthquake along one of the many earthquake faults in the region. Even a moderate earthquake could cause a local source tsunami from submarine landsliding in Monterey Bay. A local source tsunami generated by an earthquake on any of the faults affecting Santa Cruz County would arrive just minutes after the initial shock. The lack of warning time from such a nearby event would result in higher causalities than if it were a distant tsunami. 8.3.4 Assessing Vulnerability: Identifying Structures 3.4 Assessing Vulnerability: Identifying Structures – Requirement §201.6(c)(2)(ii)(A): The plan should describe vulnerability in terms of the types and numbers of existing and future buildings, infrastructure, and critical facilities located in the identified hazard area. Types and Numbers of Existing Buildings, Facilities and Infrastructure Among every type of land use within the county, approximately 2800 parcels lie within the tsunami inundation zone. The number of structures on these parcels is 1914. Expected loss in value would be $470,746,242. 8.3.5 Assessing Vulnerability: Estimating Potential Losses 3.5 Assessing Vulnerability: Estimating Potential Losses – Requirement §201.6(c)(2)(ii)(B): The plan should describe vulnerability in terms of an estimate of the potential dollar losses to vulnerable structures identified in paragraph (c)(2)(i)(A) of this section and a description of the methodology used to prepare the estimate. A. Potential dollar Losses to Vulnerable Structures County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 96 TABLE 8-1. TSUNAMI POTENTIAL LOSS INVENTORY B. Methodology Used to Prepare Estimate Parcel Valuation Valuation of parcels within a hazard area is based on improvement values only as collected by appraisers with the County of Santa Cruz assessor’s office. They don’t reflect sale value or replacement value. If a parcel intersected a hazard the entire improvement value of that parcel was used. Population Census population blocks were reduced to center points. If a hazard intersected a center point, that population was counted. Tsunami Flood Analysis Tsunamis create many risks similar to riverine and coastal flooding and the Tsunami and Flood inundation areas are similar. However, tsunamis also produce a run up that can be much more extensive than the run up that occurs with typical coastal flooding. In determining the extent of County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 97 tsunami damage an estimate must be made of the extent of the flooding. Current mapping of tsunami flooding and damage is not meant to be measured against parcel level information and therefore is a rough estimate of damage and loss in a worst-case scenario. 8.3.6 Assessing Vulnerability: Analyzing Development Trends 3.6 Assessing Vulnerability: Analyzing Development Trends – Requirement §201.6(c)(2)(ii)(C): The plan should describe vulnerability in terms of providing a general description of land uses and development trends within the community so that mitigation options can be considered in future land use decisions A. Description of Land-Uses and Development Trends As was described previously, the County of Santa Cruz has compact urban areas as well as large expanses of agricultural and forested land. Most development is now infill or reuse development, 22 although development of existing rural parcels continues. As discussed under Flood Hazards, new development is not allowed within the 100-year floodway, and must meet flood hazard regulations within the remainder of the floodplain. Reconstruction of existing structures within these areas must meet the flood elevation requirements for habitable space dictated by the FEMA guidelines and regulations. Although FEMA flooding regulations may indirectly protect against some tsunamis, these standards are inadequate as tsunami have a different direction of force and energy, and can inundate areas that are not affected by riverine or coastal flooding. 8.4.0 Mitigation Strategy 4.0 Mitigation Strategy – Requirements §201.6(c)(3): The plan shall include a mitigation strategy that provides the jurisdiction’s blueprint for reducing the potential losses identified in the risk assessment, based on existing authorities, policies, programs and resources, and its ability to expand on and improve these existing tools. The County’s current tsunami mitigation strategy is based upon notification and evacuation (see Appendix J). The strategy also includes continuation of an up-to-date Emergency Management Plan, an effective public information program and continuing collaborative efforts with the cities, agencies and community organizations to facilitate collaborative efforts in providing up-to-date tsunami mapping, preparation, information, warning dissemination and education. Mapping of tsunami inundation areas in Santa Cruz County, including the map used in this plan, is inadequate. This map should be viewed as an estimate of a worst-case scenario for planning purposes only. More accurate mapping of potential tsunami outcomes based on simulations of specific geologic events has been identified as an important component in preparing updates to this Hazard Mitigation Plan. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 98 8.4.1 Mitigation Goals 4.1 Local Hazard Mitigation Goals – Requirements §201.6(c)(3)(i): The hazard mitigation strategy shall include a description of mitigation goals to reduce or avoid long-term vulnerabilities to the identified hazards. Tsunami Goals Tsunami 1 Avoid or reduce the potential for life loss, injury, property and economic damage to Santa Cruz County from tsunami events. Tsunami 2 Continue to enhance emergency management systems including a defined public information process that includes an early warning system for evacuation prior to a tsunami event. Tsunami 3 Pursue unification of the County of Santa Cruz evacuation plan with those of the cities of Watsonville, Capitola, and Santa Cruz. 8.4.2 Identification and Analysis of Mitigation Actions 4.2 Identification and Analysis of Mitigation Actions – Requirement §201.6(c)(3)(ii): The mitigation strategy shall include a section that identifies and analyzes a comprehensive range of specific mitigation actions and projects being considered to reduce the effects of each hazard, with particular emphasis on new and existing buildings and infrastructure. Tsunami Mitigation Actions Coordinate a communication system with other agencies and cities, including evacuation operations for homes and businesses within specific areas. (A-10) Management of the early warning system including a defined public information process including establishing a reverse 911 system that will notify all homes and businesses within the tsunami inundation areas, and a public address protocol to have local and regional radio, TV and cable outlets announce evacuation notifications to the community. (B-8) Update tsunami maps (B-9) Encourage investigation of the tsunami threat to the County of Santa Cruz, and update development regulations based upon this investigation. (C-14) County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 99 CHAPTER 9 — COASTAL EROSION 9.3.0 Coastal Erosion Risk Assessment 9.3.1 Identifying Coastal Erosion Hazards 3.1 Identifying Hazards – Requirement §201.6(c)(2)(i): The risk assessment shall include a description of the type of all natural hazards that can affect the jurisdiction. Coastal erosion is the wearing away of coastal land. It is commonly used to describe the horizontal retreat of the shoreline along the ocean. Erosion can be measured as a rate, with respect to either a linear retreat (feet of shoreline recession per year) or volumetric loss (cubic yards of eroded sediment per linear foot of shoreline frontage per year). 23 Erosion rates are not uniform, and vary over time at any single location. Annual variations are the result of seasonal changes in wave action and water levels. Erosion is caused by coastal storms and flood events, changes in the geometry of tidal inlets and bays and man-made structures and human activities such as shore protection structures and dredging. Coastal erosion includes both cliff or bluff erosion and beach erosion, and is a result of both winter wave attack as well as constant wave action. Local residents will notice that beaches change seasonally in response to changes in wave conditions. Winter storm waves are larger, steeper and contain more energy, and typically move significant amounts of sand from the beaches to offshore bars, creating steep, narrow beaches. In the summer, lower, less energetic waves return the sand, widening beaches and creating gentle slopes. During the winter months when beaches are narrow, or absent altogether, the storm waves attack the cliffs and bluffs more frequently. There are many factors involved in coastal erosion, including human activity, sea-level rise, seasonal fluctuations and climate change, and sand movement will not be consistent year after year in the same location. Wind, waves, and the long-shore currents are some of the driving forces behind coastal erosion. The removal and deposition of sand creates long-term changes to beach shape and structure. Sand may be transported to landside dunes, deep ocean trenches, other beaches and deep ocean bottoms. Coastal erosion such as cliff and bluff erosion is also a result of processes related to the land such as rainfall & runoff, weathering and earthquakes. 9.3.2 Profiling Coastal Erosion Hazard Events 3.2 Profiling Hazards – Requirement §201.6(c)(2)(i): The risk assessment shall include a description of the location and extent of all natural hazards that can affect the jurisdiction. The plan shall include information on previous occurrences of hazard events and on the probability of future hazard events. A. Location: County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 100 FIGURE 25. COASTAL EROSION WITHIN COUNTY OF SANTA CRUZ The County of Santa Cruz is bounded on one side by the Pacific Ocean. The entire coastal edge of the county is affected by coastal erosion. On the north coast, where there are few structures near the coastline, the risk to structures and infrastructure is less than the coastline in the middle and southern portions of the County where homes and some businesses, as well as roads and related infrastructure are located very close to the shoreline. B. Extent: Magnitude or Severity Most of the significant cliff, bluff and dune erosion occurs in the area of the County from Live Oak to the southern County line during major winter storms at times of very high tides. The north coast area of the County also experiences coastal erosion, however, to a lesser degree. All of the cliffs along the ocean experience some degree of coastal erosion. The north coast area of the County (from the City of Santa Cruz to the Santa Cruz/San Mateo County line) is underlain by the geologically older Santa Cruz Mudstone formation, which is less susceptible to coastal erosion than areas in the County to the south. The bluffs in the Live Oak area and eastward to Rio Del Mar are underlain by the younger Purisima formation capped by terrace deposits which have been estimated to be retreating at a rate of six inches to one to two feet per year. Eolian deposits that are also sensitive to coastal erosion underlie the areas south of Rio Del County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 101 Mar. C. Previous Occurrences Approximately 85 percent of the California coast is actively eroding due to complex oceanographic and geologic conditions, and to human activities that affect the delivery and movement of sand along the coast. 24 Bluff failure takes place through processes related to the sea (mainly those that affect wave action) and to the land (rainfall and runoff, weathering, earthquakes), although the terrestrial processes are less often appreciated than the marine processes. Wave attack during periods of high tides or otherwise elevated sea level (e.g. El Niño or storm surge) is one of the most common mechanisms of episodic cliff failure. El Niño increases storm frequency, elevated sea levels, wave height and rainfall. Studies have been performed on El Niño, storm frequency, and coastal erosion history for the central California coast from 1910-1995 (Storlazzi and Griggs). This research indicated that the majority of documented coastal erosion occurred during El Niño storms that originated from the southwest. During the severe El Niño winters of 1983 and 1997-98, sea levels were further elevated and storm damage along the coastal area was extensive. Wave attack combined with a global rise in sea level over the past 18,000 years has led to the continued migration of the shoreline. At the end of the last Ice Age, about 18,000 years ago, the coastline at Santa Cruz was about 10 miles offshore. As the ice sheets and glaciers melted, sea level gradually rose and continues to rise today. Over the past several decades it has been discovered that coastal wave climate and storm frequency are related to larger scale climatic oscillations that affect the entire Pacific Ocean. During the time period from about 1945 to 1978, the California coast was characterized by a fairly calm climate, few large storms, less rainfall and less coastal erosion and storm damage. Beginning in 1978 and continuing until 1998, California experienced a period of more frequent and severe El Niño events with associated elevated sea levels, large waves, heavier rainfall and more extensive coastal storm damage and cliff and beach erosion. D. Probability of Future Events While the sea level rose a little less than a foot over the past century, most scientists are concerned that due to the increase in greenhouse gases from human activity, warming will accelerate. As a result, glaciers will continue to retreat and the rate of sea level rise will increase, with the best estimate being about three feet higher by 2100. Given this estimate, the probability of future coastal erosion is very high. 9.3.3 Assessing Coastal Erosion Vulnerability: Overview 3.3 Assessing Vulnerability: Overview – Requirement §201.6(c)(2)(ii): The risk assessment shall include a description of the jurisdiction’s vulnerability to the hazards described in paragraph (c)(2)(i) of this section. This description shall include an overall summary of each hazard and its impact on the community. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 102 A. Overall Summary of Vulnerability to Coastal Erosion Much of the Santa Cruz County coastline, particularly in the developed areas, has some level of armoring (walls, riprap, etc.). The majority of the protection structures have been installed within the last 40 years, and they have varying levels of adequacy and performance. While these protection structures help protect buildings and infrastructure during storms, they are still vulnerable to failure during larger storm events and may not provide full protection. Riprap structures along the coastline are particularly vulnerable to failure and require more maintenance and upgrading over time than the concrete seawalls. While the entire Santa Cruz coast is subject to coastal erosion, the primary locations vulnerable to coastal erosion are the areas from the Santa Cruz Harbor eastward toward Pleasure Point, the area from Pleasure Point to Opal Cliffs, and the area south of New Brighton Beach to the southern Santa Cruz County line. The area from the Santa Cruz Harbor to Pleasure Point contains numerous homes on the coastal bluff as well as roads and other infrastructure, particularly near the coastal lagoons, that are vulnerable to coastal erosion. There are also several sea caves that may affect the integrity of homes and infrastructure in this area as well. The primary type of coastal armoring in this area is riprap. It is not uncommon for East Cliff Drive to be closed or damaged where it crosses Schwann Lake, Corcoran Lagoon and Moran Lake during large winter storms. Many of the homes that exist along the coast in this area, although somewhat protected, may be subject to further coastal erosion as sea levels rise, earthquakes occur, and waves and rainfall impact the coast. The area from Pleasure Point to Opal Cliffs also contains numerous homes on the costal bluff as well as roads and other infrastructure that are vulnerable to coastal erosion. The coastal armoring in this area is a mix of riprap, concrete seawalls and a combination of both. Currently a seawall is being constructed in the Pleasure Point area along East Cliff Drive that should greatly reduce potential damage from coastal erosion to East Cliff Drive as well as the homes on the other side of the road. Many of the homes that exist along the coast in this area, although somewhat protected, may be subject to further coastal erosion as sea levels rise, earthquakes occur, and waves and rainfall impact the coast. The area south of New Brighton Beach to the southern Santa Cruz County line contains numerous homes on the bluffs, at the base of the bluffs and on the beach. There is also infrastructure and several County roads on the beach and bluffs that may be affected by coastal erosion. Many of the homes along and above both Las Olas Drive and Beach Drive will experience the continuing effects of coastal erosion. There are also several other communities (including Seascape, La Selva Beach, Sunset Beach and Pajaro Dunes) that are vulnerable to coastal erosion. Many of the homes that exist along the coast in this area, although somewhat protected, may be subject to further coastal erosion as sea levels rise, earthquakes occur, and waves and rainfall impact the coast. Along the north coast of the County of Santa Cruz, regulations have limited development and structures have been constructed in very limited locations. Although seawalls reduce or delay coastal erosion processes as long as they remain functioning, ultimately coastal erosion continues and the best seawalls need maintenance. While seawalls remain in place, they modify coastal erosion through the reduction of wave County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 103 erosion energy, or reflection or refraction of wave energy. Focused erosion can occur at the ends of the seawalls. While seawalls are helpful in protecting against coastal erosion, proper setbacks from the brow of bluffs, drainage control, and special construction are all necessary to protect structures, roadways, and utilities from damage. 9.3.4 Assessing Vulnerability: Identifying Structures 3.4 Assessing Vulnerability: Identifying Structures – Requirement §201.6(c)(2)(ii)(A): The plan should describe vulnerability in terms of the types and numbers of existing and future buildings, infrastructure, and critical facilities located in the identified hazard area. A. Types and Numbers of Existing Buildings, Facilities and Infrastructure There are approximately 550 residential parcels affected by coastal erosion. Of this number, 104 are structures with a potential loss of $141,482,428. 9.3.5 Assessing Vulnerability: Estimating Potential Losses 3.5 Assessing Vulnerability: Estimating Potential Losses – Requirement §201.6(c)(2)(ii)(B): The plan should describe vulnerability in terms of an estimate of the potential dollar losses to vulnerable structures identified in paragraph (c)(2)(i)(A) of this section and a description of the methodology used to prepare the estimate. A. Potential Dollar Losses to Vulnerable Structures – See table on following page County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 104 TABLE 9-1. COASTAL EROSION POTENTIAL LOSS INVENTORY B. Methodology Used to Prepare Estimate Assessor’s valuations were used. Potential dollar losses also include replacement of roads and paths, including property acquisition. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 105 9.3.6 Assessing Vulnerability: Analyzing Development Trends 3.6 Assessing Vulnerability: Analyzing Development Trends – Requirement §201.6(c)(2)(ii)(C): The plan should describe vulnerability in terms of providing a general description of land uses and development trends within the community so that mitigation options can be considered in future land use decisions. A. Description of Land-Uses & Development Trends Every coastal community in California is dealing with the issues of sea level rise and shoreline retreat armoring is becoming an increasingly controversial and contentious issue. Since seawalls now protect so much of the developed portion of the County of Santa Cruz coastline, the controversy now centers on improving these walls and their impacts. Coastal erosion poses many problems to coastal communities in that valuable property is frequently lost to this dynamic beach-ocean system. Additionally, human activity may modify the process of coastal erosion with uncertain results. Thus, issues of beach restoration and erosion control are at the forefront in coastal communities. The County of Santa Cruz’s shoreline is now part of the Monterey Bay Marine Sanctuary, which will also influence development trends along the Santa Cruz coast. The majority of the undeveloped areas along the coastline are farmland or other areas currently protected from development. The current trend in development along the coastline in Santa Cruz County is in-fill within the developed areas and reconstruction of existing structures and infrastructure. The County of Santa Cruz’s Geologic Hazards Ordinance Section 16.10.070(h) requires development on coastal bluffs and beaches to be reviewed by the County Geologist. The ordinance requires development to be setback at least 25 feet from the top of a coastal bluff, or the distance required to provide 100-year stability, whichever is greater. Shoreline protection structures are also subject to the County’s Geologic Hazards Ordinance and review by the County Geologist. Most current seawall permits are for maintenance and improvement of existing walls, which allows the County of Santa Cruz to require modifications that reduce the walls’ impacts. 9.4.0 Mitigation Strategy 4.0 Mitigation Strategy – Requirement §201.6(c)(3): The plan shall include a mitigation strategy that provides the jurisdiction’s blueprint for reducing the potential losses identified in the risk assessment based on existing authorities, policies, programs and resources, and its ability to expand on and improve these existing tools. 9.4.1 Local Hazard Mitigation Goals 4.1 Local Hazard Mitigation Goals – Requirement §201.6(c)(3)(i): The hazard mitigation strategy shall include a description of mitigation goals to reduce or avoid long-term vulnerabilities to the identified hazards. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 106 Coastal Erosion Goals: Coastal Erosion 1 Coastal Erosion 2 Coastal Erosion 3 Avoid or reduce the potential for life loss, injury, property and economic damage to the County of Santa Cruz from coastal erosion. Protect and preserve natural resources. Protect and preserve current infrastructure. 9.4.2 Identification and Analysis of Mitigation Actions 4.2 Identification and Analysis of Mitigation Actions – Requirement §201.6(c)(3)(ii): The mitigation strategy shall include a section that identifies and analyzes a comprehensive range of specific mitigation actions and projects being considered to reduce the effects of each hazard, with particular emphasis on new and existing buildings and infrastructure. Coastal Erosion Mitigation Actions Protect and preserve the coastline through permit review and continue to review coastal development for conformance with the County’s Geologic Hazards ordinance. (B-10) Encourage the replacement of existing seawalls with better-designed walls that result in less of an impact. (B-11) Protect and preserve the coastline and infrastructure through restoration efforts (C15) Minimizing Hazards from Coastal Erosion Much of the urban coastline in the County has boulder riprap or concrete seawalls to minimize the energetic wave impacts that drive cliff erosion and to protect residences and infrastructure. Because these structures have finite life spans and can have adverse effects on other parts of the coast, engineering solutions can be very expensive in both the short-term and long-term. In other cases, the solution is to leave the coastline relatively undeveloped and to allow erosion to occur naturally. This option preserves the normal input of sand into the littoral drift system, perhaps lessening erosion at neighboring beaches. The three primary management strategies that may be used to plan for and respond to coastal erosion are hazard avoidance, relocation, and coastal protection. The maximum potential efficacy and acceptability of these strategies can best be determined with multi-disciplinary project planning, design, monitoring and evaluation. Hazard Avoidance – A Commonsense Approach The most logical method for preventing potential damage to new development in the coastal zone is to avoid building where coastal erosion will impact such development. This concept, known as hazard avoidance, could circumvent many subsequent permitting and legal challenges. Hazard avoidance has proven effective when used in a number of ways including designing public infrastructure to discourage development in high geologic hazard areas along the coast. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 107 Relocation – Moving Development Out of Harm’s Way In some instances, development is sited in unstable, erosion-prone areas that may be damaged or destroyed by natural processes acting on the coast. Relocating existing public or private development away from erosion-prone areas may be the most effective long-term option when responding to the eventual or imminent threat of damage. While relocating coastal development away from hazardous areas would be the most direct way to eliminate the risk of damage and the need for coastal protection, this response may not be technically, financially or legally feasible. Another approach to consider under certain circumstances is the concept of “managed retreat,” that is the gradual removal or abandonment of development from areas of high geologic hazard. In the context of coastal management, the concept of managed retreat acknowledges the natural erosive processes at work along the coast. Coastal Protection In situations where hazard avoidance and relocation are not viable options, coastal protection strategies can be used to reduce the potential for beach loss and coastal erosion. There are two general types of coastal protection, hard and soft. A “hard” protection device utilizes concrete or rock in a variety of configurations to absorb or dissipate storm wave energy, generally in the form of seawalls, revetments or bulkheads. "Soft" protection primarily involves dune or beach restoration or enhancement to reduce the chances of storm waves from reaching the backshore. A hard protection device differs substantially from most soft erosion response alternatives in that it does not add sand to the system of sediment. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 108 CHAPTER 10 — DAM FAILURE 10.3.0 Dam Failure Risk Assessment 10.3.1 Identifying Dam Failure Hazards 3.1 Identifying Hazards – Requirement §201.6(c)(2)(i): The risk assessment shall include a description of the type of all natural hazards that can affect the jurisdiction. Dam failure can occur as a result of earthquakes, seiches, structural instability, or intense rain in excess of design capacity. Timber, rock, concrete, earth, steel or a combination of these materials may be used to build a dam. Dams must have spillway systems to safely convey normal stream and flood flows over, around, or through the dam. Spillways are commonly constructed of non-erosive materials such as concrete. Dams also have a drain or other waterwithdrawal facility to control the reservoir level and to lower or drain the reservoir for normal maintenance and emergency purposes. 10.3.2 Profiling Dam Failure Hazard Events 3.2 Profiling Hazards – Requirement §201.6(c)(2)(i): The risk assessment shall include a description of the location and extent of all natural hazards that can affect the jurisdiction. The plan shall include information on previous occurrences of hazard events and on the probability of future hazard events. A. Location As reflected in table 10-1 on the following page, there are six dams located within the County of Santa Cruz that, based on their size, are regulated by the State Division of Safety of Dams. Two of these, the Bay Street Reservoir and Newell Dam, are within the jurisdiction of the City of Santa Cruz. The remaining four include: 1) Mill Creek Dam at the Lockheed facility near the end of Empire Grade in northern Santa Cruz County, 2) Sempervirens Dam within Big Basin Redwoods State Park, 3) Oak Site Dam found near the Lockheed facility, and 4) Soda Lake located along Highway 129 in southeastern Santa Cruz County. None of these dams are owned or operated by the County of Santa Cruz, but are the responsibilities of other state agencies or private entities. The reservoirs range in size from 20 acre-feet to over 10,000 acrefeet, with the oldest dam being constructed in the late 1890s and the newest in 1985. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 109 FIGURE 26. INUNDATION AREA FOR NEWELL CREEK DAM FAILURE County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 110 Three additional State-regulated dams, located in neighboring counties, also have the potential to affect Santa Cruz County residents and properties should they be compromised or fail. These include Elmer J Chesbro Dam and Uvas Dam in Santa Clara County and the San Justo Dam in San Benito County. The Santa Clara Valley Water District is responsible for Elmer J Chesbro and Uvas reservoirs, while San Justo reservoir is the responsibility of the San Benito County Water District under contract with the Federal Bureau of Reclamation. Programs to ensure ongoing dam safety are implemented by these agencies. TABLE 10-1. LIST OF DAMS WITHIN AND ADJACENT TO COUNTY OF SANTA CRUZ Name Owner County Mill Creek Lockheed Missiles Santa Cruz and Space Co. Oak Site State Dept of Forestry Santa Cruz Sempervirens California Dept of Santa Cruz Parks and Recreation Soda Lake Granite Rock Co. Santa Cruz Bay Street City of Santa Cruz Santa Cruz Reservoir Newell City of Santa Cruz Santa Cruz Elmer J Chesbro Uvas San Justo Santa Clara Valley Wd Santa Clara Valley Wd Bureau of Reclamation Stream Res. Area (Acres) 223 12 Year Capacity Built (Ac-ft) Mill Creek 1889 Tr. Big Creek Sempervirens Creek Tr. Pajaro River Offstream 1969 1951 20 78 2 4 1978 1924 1,983 112 72 5 Newell Creek 1960 (SLR) Santa Clara Llagas Creek (PR) 1955 8,991 172 8,086 328 Santa Clara Uvas Creek (PR) 1957 10,000 280 San Benito Offstream 1985 10,300 202 There are also a total of eight mining operations in Santa Cruz County that utilize ponds to hold processing plant wash water and storm water. These ponds are constructed using both artificial and natural barriers depending on whether the pond is created by a levee or dam, or excavation below grade. Because of limited dam height or storage capacity none of these ponds is within the jurisdiction of the State of California Division of Safety of Dams. In some cases quarry ponds are non-jurisdictional because they are created by excavation, which means there is no artificial barrier that would qualify as a “dam” under State law. There are an unknown number of other dams in the County associated with agriculture, small water systems and private ponds. These facilities are likely non-jurisdictional. Santa Cruz County Planning Department files may contain documentation for some of these dams while a number of others are undocumented. B. Extent: Magnitude or Severity Given their location, a major dam failure at either the Bay Street Reservoir or Newell Creek Dam could result in extensive property damage or loss of life in the San Lorenzo Valley and the City of Santa Cruz. A dam failure at either the Mill Creek, Oak Site or Sempervirens dams could affect people and property in northern Santa Cruz County, to the east of the community County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 111 of Boulder Creek. Soda Lake is a storage facility for fine-grained material or “fines” from the Wilson Quarry in San Benito County. Failure of the Soda Lake levees could potentially release this material and impact one or more nearby residences and encroach upon Highway 129. Although located in neighboring counties, a failure of the Elmer J Chesbro, Uvas, or San Justo dams could potentially impact people and properties along the Pajaro River in Santa Cruz County. Given their location, failure of a non-jurisdictional dam or levee at a quarry pond could affect a limited amount of people or property in downstream areas. For an unknown number of dams, which are likely non-jurisdictional, the extent of the dam failure hazard is unknown at this time. C. Previous Occurrences There have been no reported dam failures for either the Bay Street Reservoir or Newell Creek facility. There have been no reported failures at the Mill Creek, Oak Site or Sempervirens dams. Because the Elmer J Chesbro, Uvas and San Justo dams are located in adjacent counties, information is not readily available regarding previous dam failures, if any. After the Loma Prieta Earthquake, an extensive set of cracks was observed at the crest of the Soda Lake west embankment and adjacent areas on the levee’s interior face. The west levee was excavated to bedrock and reconstructed in 1997 with the approval of the California Division of Safety of Dams. Additional stability issues involving the north levee tie-in to the hillside have been addressed by the Division of Safety of Dams in a letter to Graniterock Company dated September 20, 2000. According to Planning Department records there have been no dam failures at any of the mines in Santa Cruz County. There have been rare events involving uncontrolled releases of water due to natural and human causes, but none of these events involved dam failure. Previous occurrences of dam failure affecting Santa Cruz County are not known for any other dams. D. Probability of Future Events Currently available information gives no indication that any of the dams would fail or otherwise sustain damage under any circumstance (This does not include man-made disaster). A stability issue involving a quarry pond is being addressed with the quarry operator. The Division of Safety of Dams is aware of the issue involving the north levee of Soda Lake. 10.3.3 Assessing Dam Failure Vulnerability: Overview 3.3 Assessing Vulnerability: Overview – Requirements §201.6(c)(2)(ii): The risk assessment shall include a description of the jurisdiction’s vulnerability to the hazards described in paragraph (c)(2)(i) of this section. This description shall include an overall summary of each hazard and its impact on the community. A. Overall Summary of Vulnerability to Dam Failure The losses to life and property associated with complete dam failure would be high. Given the County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 112 monitoring protocol at the Newell Creek and Bay Street reservoirs, the probability of dam failure is very low. 10.3.4 Assessing Vulnerability: Identifying Structures 3.4 Assessing Vulnerability: Identifying Structures – Requirement §201.6(c)(2)(ii)(A): The plan should describe vulnerability in terms of the types and numbers of existing and future buildings, infrastructure, and critical facilities located in the identified hazard area. A. Types and Numbers of Existing Buildings, Facilities and Infrastructure Up-to-date information on numbers of existing buildings, infrastructure and critical facilities is not available at this time. A Seismic Safety Element was prepared for the County of Santa Cruz General Plan in 1975. This document contains inundation maps for the Newell Creek, Bay Street and Sempervirens dams, which have not been updated. In the event of a dam or levee failure at a quarry pond, significant environmental impacts and property damage could occur. Environmental impacts would likely be limited to temporary impacts on water quality and erosion. Property damage would likely be limited to impacts on downstream drains, culverts, roads and bridges. 10.3.5 Assessing Vulnerability: Estimating Potential Losses 3.5 Assessing Vulnerability: Estimating Potential Losses – Requirement §201.6(c)(2)(ii)(B): The plan should describe vulnerability in terms of an estimate of the potential dollar losses to vulnerable structures identified in paragraph (c)(2)(i)(A) of this section and a description of the methodology used to prepare the estimate. A. Dollar Losses to Vulnerable Structures As the following table illustrates, the majority of structures within the inundation area are residential. For this land use category alone, the loss would be approximately $171 million dollars. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 113 TABLE 10-2 . DAM FAILURE POTENTIAL LOSS INVENTORY B. Methodology Used to Prepare Estimate Valuation of parcels within the hazard area are based on improvement values only as collected by the County of Santa Cruz Assessor’s Office. They do not reflect sale or replacement value. If a parcel intersected a hazard, the entire improvement value of that parcel was used. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 114 10.3.6 Assessing Vulnerability: Analyzing Development Trends 3.6 Assessing Vulnerability: Analyzing Development Trends – Requirement §201.6(c)(2)(ii)(C): The plan should describe vulnerability in terms of providing a general description of land uses and development trends within the community so that mitigation options can be considered in future land use decisions. A. Description of Land-Uses and Development Trends The County of Santa Cruz has a number of compact urban communities as well as extensive areas of agricultural land and forested hillsides. A number of rural villages and towns are located throughout the County. As dictated by the 1978 Growth Management Ordinance, most new development has occurred within or adjacent to the urban services line (i.e., the boundary point for such infrastructure as water and sewage service). As with most communities, increased housing costs have resulted in the need to provide higher density housing. 25 In Santa Cruz County, all development of this type occurs where urban services are available. Other development is mostly infill or reuse development, and development of existing rural residential properties. There is limited potential for significant expansion of mining activities in Santa Cruz County. As quarry resources are depleted, the sites are reclaimed. Reclamation will include elimination of unnecessary water impoundments and eliminating any danger to public health and safety from failure of any remaining dams or levees. 10.4.0 Mitigation Strategy 4.0 Mitigation Strategy – Requirement §201.6(c)(3): The plan shall include a mitigation strategy that provides the jurisdiction’s blueprint for reducing the potential losses identified in the risk assessment, based on existing authorities, policies, programs and resources, and its ability to expand on and improve these existing tools. The primary mitigation strategy is the continuation of monitoring protocols for structural integrity. The City of Santa Cruz is responsible for monitoring of both the Bay Street Reservoir and the Newell Creek Dam. The Santa Cruz County Planning Department regulates mining operations in the County. All quarry ponds have been reviewed for geotechnical stability and hydrologic capacity as part of the permitting process for each mine. In addition, mine sites are inspected on a regular basis, which includes verifying the current conditions of ponds and conformance with approved plans. As a result, any necessary remedial measures identified during the permit process, or ongoing inspections, are addressed as part of the quarry inspection process. The mitigation strategy for other dams in Santa Cruz County would involve documentation and site inspection to determine what, if any, further documentation or remedial actions may be needed. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 115 10.4.1 Mitigation Goals 4.1 Local Hazard Mitigation Goals – Requirement §201.6(c)(3)(i): The hazard mitigation strategy shall include a description of mitigation goals to reduce or avoid long-term vulnerabilities to the identified hazards. Dam Failure Goal Avoid or reduce the potential for life loss, injury, property or economic damage to Santa Cruz from dam failure. 10.4.2 Identification and Analysis of Mitigation Actions 4.2 Identification and Analysis of Mitigation Actions – Requirement §201.6(c)(3)(ii): The mitigation strategy shall include a section that identifies and analyzes a comprehensive range of specific mitigation actions and projects being considered to reduce the effects of each hazard, with particular emphasis on new and existing buildings and infrastructure. Dam Failure Mitigation Actions Develop an event protocol with the State Division of the Safety of Dams. (B-12) Update dam inundation maps. (C-16) Review Planning Department files and other available information for the purpose of locating any other dams in Santa Cruz County to determine the extent of possible damage. (C-17) County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 116 CHAPTER 11 — LANDSLIDE 11.3.0 Landslide Risk Assessment 11.3.1 Identifying Landslide Hazards 3.1 Identifying Hazards – Requirement §201.6(c)(2)(i): The risk assessment shall include a description of the type of all natural hazards that can affect the jurisdiction. Landsliding is a general term that describes a wide variety of mass downslope movements of soil and rock in response to gravity. Landsliding occurs as falls, topples, slides, spreads, flows, and a combination of these categories, and may change from one form failure to another during their movement. Factors causing landsliding include the rock strength and orientation of elements on the slope, erosion, weathering, high rainfall, steepness of slopes, and human activities such as the removal of vegetation and inappropriate grading. Landslides occur throughout the world, but Santa Cruz County’s unique geologic conditions make large portions of the County particularly susceptible to many forms of landsliding. Factors that contribute to landsliding in Santa Cruz County include: storms earthquakes fires freezing and thawing erosion vegetation removal, grading and other human activities. Landslide problems can also be caused by land mismanagement, particularly in mountain, canyon, and coastal regions. In areas burned by forest and brush fires, a lower threshold of precipitation may initiate landslides. The deterioration of old timber harvest roads may also result in concentration of drainage that induces landsliding. The County of Santa Cruz’s General Plan 26, along with Chapter 16.10 of the County Code set standards to reduce damage from landslides through avoidance of hazardous areas and/or mitigation. These County standards, along with the California Building Code and good engineering practices minimize many landslide problems, but don’t eliminate them. Landsliding occurs throughout Santa Cruz County, but is centered primarily along the steeper slopes in the hills and mountains, along stream corridors, and along coastal bluffs and inlets. Large areas of the County are subject to several forms of landsliding as indicated in Figures 27 and 28, but isolated sliding occurs throughout the County. The types of landsliding that occur in Santa Cruz can be summarized as follows: Coastal Bluffs: Shallow landslides, debris flows and topples Rivers and streams: Shallow landslides, rotational landslides, and lateral spreading Hillslopes: Large deep composite landslides, and debris flows. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 117 11.3.2 Profiling Landslide Hazard Events 3.2 Profiling Hazards – Requirement §201.6(c)(2)(i): The risk assessment shall include a description of the location and extent of all natural hazards that can affect the jurisdiction. The plan shall include information on previous occurrences of hazard events and on the probability of future hazard events. A. Location SUMMARY DISTRIBUTION OF SLIDES & EARTH FLOWS IN SANTA CRUZ COUNTY 27 By Carl M. Wentworth, Scott E. Graham, Richard J. Pike, Gregg S. Beukelman, David W. Ramsey, and Andrew D. Barron FIGURE 27. SLIDES & EARTHFLOWS IN SANTA CRUZ COUNTY MAP UNITS Mostly Landslide - consists of mapped landslides, intervening areas typically narrower than 1500 feet, and narrow borders around landslides; defined by drawing envelopes around groups of mapped landslides. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 Many Landslides - consists of mapped landslides and more extensive intervening areas than in 'Mostly Landslide'; defined by excluding areas free of mapped landslides; outer boundaries are quadrangle and County limits to the areas in which this unit was defined. 118 Few Landslides - contains few, if any, large mapped landslides, but locally contains scattered small landslides and questionably identified larger landslides; defined in most of the region by excluding groups of mapped landslides but defined directly in areas containing the 'Many Landslides' unit by drawing envelopes around areas free of mapped landslides. Flat Land - areas of gentle slope at low elevation that have little or no potential for the formation of slumps, translational slides, or earth flows except along stream banks and terrace margins; defined by the distribution of surficial deposits (Wentworth, 1997). FIGURE 28. POTENTIAL SLIDE THREATS TO SANTA CRUZ COUNTY B. Extent: Magnitude or Severity Landslides are a common occurrence in the Santa Cruz Mountains. Our intense winter storms, high rainfall amounts, especially during El Nino weather patterns, and steep terrain are conducive to landsliding. Earthquake activity contributes to this landsliding, as illustrated by the 1906 earthquake, which set off dozens of large landslides in the Santa Cruz Mountains, some of which claimed human lives. The 1989 Loma Prieta earthquake produced a similar pattern of landsliding. The potential for loss of life and property is much greater today due to the increase in population residing in areas of possible instability. Most recent landslides in the Santa Cruz Mountains have been caused by a combination of human activity and natural factors. Human activities that act to further destabilize slopes, are old timber harvest roads and skid trails, conversion of land from forest to residential and agricultural uses, road building, grading and other housing construction and any activity that alters normal drainage patterns. The likelihood that any of these factors will contribute to County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 119 landsliding is dependent upon the existing conditions and also on the care with which activities are conducted in these locations. County Code Section 16.10 in combination with the California Building Code require careful consideration of landslide factors by both engineering geologists, soils engineers, and civil engineers. However, even with proper care, there remains a higher than normal potential for damage from landsliding in many areas of the County. C. Previous Occurrences Several periods of landsliding have occurred in Santa Cruz County in recent history. Some of the better-documented landslides are: Mount Hermon Landslide: The Mountain Hermon landslide moved in the late 1950’s after the El Nino year of 1957 –1958. This landsliding occurred in an area of suspected older landsliding and the new movement extended from the Kaiser Quarry to the bottom of Bean Creek blocking Mount Hermon Road, and is one of the reasons for construction of the Mount Hermon bypass. At the time of the landsliding there was some concern that the quarry (and a small earthquake) may have contributed to the re-initiation of the landslide. Rain Storms of January 1982: Severe storms caused multiple landslides throughout the Bay Area and especially in the Santa Cruz Mountains. One very large composite landslide along Love Creek, west of Loch Lomond Reservoir, killed ten people. This landslide was and continues to be an indicator of the potential severity of landslide activity and the need for observation and/or mitigation. Other landslides, including debris flows, destroyed homes killing several other people. In addition to damage to homes, widespread landslide damage occurred to roadways, driveways, and stream channels. Loma Prieta Earthquake October 17, 1989: Landslides occurred throughout the County of Santa Cruz during and after the October 17, 1989 Loma Prieta earthquake. Most of these larger landslides moved only during the actual shaking, but others continue to the present. Smaller landslides occurred along coastal bluffs and along ridge-tops. El Nino Winter Storms of 1986, 1998, and 2005: These storms caused multiple landslides, particularly debris flows, throughout the Santa Cruz Mountains. During the 1998 winter, many homes were affected by landsliding and several roadways were damaged including Highway 9, Branciforte Road, and Amesti Road. Winter rains also induced landsliding within the quarries throughout the County. D. Probability of Future Events Landsliding will continue to affect the County, especially during El Nino weather patterns. Most of the critical structures within the County of Santa Cruz are located away from landslides, but many homes and roadways are located in and around landslides. El Nino weather patterns will continue approximately every seven years, and the San Andreas Fault, as well as other faults, will generate earthquakes, which will contribute to the formation of landslides. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 120 11.3.3 Assessing Landslide Vulnerability: Overview 3.3 Assessing Vulnerability: Overview – Requirement §201.6(c)(2)(ii): The risk assessment shall include a description of the jurisdiction’s vulnerability to the hazards described in paragraph (c)(2)(i) of this section. This description shall include an overall summary of each hazard and its impact on the community. Past experience has shown that many areas of the County are susceptible to the effects of landslides. Most of the damage caused by landslides will be to privately owned structures although a fair number of County maintained roads are also at risk. A. Overall Summary of Vulnerability to Landslide The County of Santa Cruz terrain, weather, and seismicity increase the likelihood of landsliding. Homes built before 1989 are particularly vulnerable to landslides as some of these were constructed without the benefit of engineering or engineering geologic investigations. Most of the roadways were constructed many years ago with little consideration to slope stability, and will likely be affected by landsliding in the future. Because utilities follow these roads, damage to roads will often disrupt sewers, water systems, gas and electricity, and cable and telephone utilities. Areas that have experienced landsliding include: 1. The steep hillslopes throughout the County of Santa Cruz, especially near the Zayante and San Andreas fault zones, and within the San Lorenzo Valley and Eureka Canyon. 2. The river channels along major streams, and along the edges of the broader alluvial Pajaro River and Corralitos Creek. 3. Along coastal bluffs, especially above Beach and Las Olas drives, and above Sunset Beach in the Seacliff Beach area. 11.3.4 Assessing Vulnerability: Identifying Structures 3.4 Assessing Vulnerability: Identifying Structures – Requirement §201.6(c)(2)(ii)(A): The plan should describe vulnerability in terms of the types and numbers of existing and future buildings, infrastructure, and critical facilities located in the identified hazard area. Landslides threaten relatively few public buildings, but over 16,000 residences are potentially at risk, with over 21,000 structures on these parcels. This represents over 3 billion dollars worth of property. See Table 11-1 for the type of structures and their value. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 121 Types and Numbers of Existing Buildings, Facilities and Infrastructure TABLE 11-1. LANDSLIDE POTENTIAL LOSS INVENTORY 11.3.5 Assessing Vulnerability: Estimating Potential Losses 3.5 Assessing Vulnerability: Estimating Potential Losses – Requirement §201.6(c)(2)(ii)(B): The plan should describe vulnerability in terms of an estimate of the potential dollar losses to vulnerable structures identified in paragraph (c)(2)(i)(A) of this section and a description of the methodology used to prepare the estimate. Once again, we see that residential structures are the ones most impacted by landslide danger. Over 16,000 residential parcels have been identified as under threat from landslide. There are over 21,200 structures on these parcels, which represent a value of over $3 billion dollars. B. Methodology Used to Prepare Estimate County of Santa Cruz Tax Assessor’s valuations were used to prepare this report. Potential dollar losses also include replacement of roads, paths and property acquisition. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 122 11.3.6 Assessing Vulnerability: Analyzing Development Trends 3.6 Assessing Vulnerability: Analyzing Development Trends – Requirement §201.6(c)(2)(ii)(C): The plan should describe vulnerability in terms of providing a general description of land uses and development trends within the community so that mitigation options can be considered in future land use decisions. A. Description of Land-Uses and Development Trends The County of Santa Cruz has a number of compact urban communities as well as extensive areas of agricultural land and forested hillsides. A number of rural villages and towns are located throughout the County. As dictated by the 1978 Growth Management Ordinance, most new development has occurred within or adjacent to the urban services line (i.e., the boundary point for such infrastructure as water and sewage service). As with most communities, increased housing costs have resulted in the need to provide higher density housing. In Santa Cruz County, all development of this type occurs where urban services are available. Other development is mostly infill or reuse development, and development of existing rural residential properties. Growth management policies prevent development from occurring where hazards are present and, in most cases, require substantial setbacks from these hazards. 28 11.4.0 Mitigation Strategy 4.0 Mitigation Strategy – Requirement §201.6(c)(3): The plan shall include a mitigation strategy that provides the jurisdiction’s blueprint for reducing the potential losses identified in the risk assessment, based on existing authorities, policies, programs and resources, and its ability to expand on and improve these existing tools. The County’s over-all strategy to mitigate landslide hazards is to: 1) require the involvement of qualified experts in identifying specific landslide hazards, 2) maintain records of the types and locations of these hazards, 3) require that new development avoid landslide areas whenever possible, and 4) ensure that building plans incorporate all reasonable mitigation measures for structures that must be sited in or near hazard areas. 11.4.1 Mitigation Goals 4.1 Local Hazard Mitigation Goals – Requirement §201.6(c)(3)(i): The hazard mitigation strategy shall include a description of mitigation goals to reduce or avoid long-term vulnerabilities to the identified hazards. Landslide Goals Landslide 1 Avoid and reduce the potential for life loss, injury, property and economic damage from landslide hazards County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 123 11.4.2 Identification and Analysis of Mitigation Actions 4.2 Identification and Analysis of Mitigation Actions – Requirement §201.6(c)(3)(ii): The mitigation strategy shall include a section that identifies and analyzes a comprehensive range of specific mitigation actions and projects being considered to reduce the effects of each hazard, with particular emphasis on new and existing buildings and infrastructure. Landslide Mitigation Actions Continue to require that the County Geologist review development in areas of suspected landsliding and require engineering geology reports when landsliding is identified or suspected. (C-18) Continue to require that an engineering geologist and/or geotechnical engineer investigate the site of any proposed construction near landsliding and require mitigation of landslide hazards before issuing any building or grading permits. (C-19) Continue to require that an engineering geologist and/or a geotechnical engineer investigate any landslide damage to homes or roadways before repair of the landslide and reuse of the homes or roadways. (C-20) County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 124 CHAPTER 12 — EXPANSIVE SOILS 12.3.0 Expansive Soils Risk Assessment 12.3.1 Identifying Expansive Soils Hazards 3.1 Identifying Hazards – Requirement §201.6(c)(2)(I): The risk assessment shall include a description of the type of all natural hazards that can affect the jurisdiction. Expansive soils are generally clays or sedimentary rocks derived from clays, which experience volume changes as a result of moisture variation. The hazard that expansive soils create can be significant. Many of the expansive soils do not create large areas of destruction; however, they can disrupt supply lines (i.e. roads, power lines, railways, and bridges) and damage structures. The effects on structures can be dramatic if expansive soils supporting structures are allowed to become too wet or too dry. Lightly loaded one-story or two-story buildings, warehouses, residences, and pavements are especially vulnerable to damage because these structures are less able to suppress the differential heave of the swelling foundation soil than heavy, multistory structures. Patios, driveways and walkways may also crack and heave as the underlying expansive soils become wet and swell. Expansive soils do not change size quickly; observing damage in real-time can sometimes be difficult. Although the damage might not occur in a matter of minutes, it still has the potential to severely damage structures and roads over a matter of time if not sufficiently mitigated. Many areas of Santa Cruz County are underlain by expansive soils. However, expansive soil doesn't cause problems unless poorly designed structures are built on it. A house built on expansive soil will probably move if the foundation was not designed to take this soil type into account. Movement occurs because the soils expand so forcefully, the foundation actually moves. Different parts of the house can move at different rates and distances, thus cracking the foundation. Significant cracks often appear at the corners of windows and doors, in walls, garage slabs, walkways, and driveways. Doors and windows may become jammed. The integrity, design, value and use of a home could be affected. During extreme drought conditions, even homes that are not normally affected by expansive soil problems may experience slight cracking. 12.3.2 Profiling Expansive Soils Hazard Events 3.2 Profiling Hazards – Requirement §201.6(c)(2)(i): The risk assessment shall include a description of the location and extent of all natural hazards that can affect the jurisdiction. The plan shall include information on previous occurrences of hazard events and on the probability of future hazard events. A. Location County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 125 The general areas of expansive soils within the County of Santa Cruz are known. The National Resource Conservation Service’s (NRCS) Soil Survey of Santa Cruz County mapped various soils types throughout the County. In addition, soils reports performed over the years throughout the County for building permits have corroborated the locations of expansive soils. The primary soil types mapped by NRCS as expansive are Watsonville Loam, Clear Lake Clay, Diablo Clay, Fagan Loam, Los Osos Loam, Mocho Silt Loam, Pinto Loam, Felton Sandy Loam, Cropley Silty Clay, Danville Loam and Lompico Varient Loam. The general locations of expansive soils are in the coastal terraces in Live Oak, Seacliff and Rio Del Mar and in South County near Watsonville. However, smaller pockets of expansive soils may exist throughout the County. FIGURE 29. EXPANSIVE SOILS WITHIN COUNTY OF SANTA CRUZ B. Extent: Magnitude or Severity Each year in the United States, expansive soils cause billions of dollars in damage to buildings, roads, pipelines, and other structures. This is more damage than that caused by floods, hurricanes, tornadoes, and earthquakes combined (FEMA 1997). It is estimated that the County of Santa Cruz has thousands of homes built on expansive soils. Typically, the structures that experience problems with expansive soils are older homes, but newer homes (built within the last 15 years) may also experience problems due to expansive soils. The types of problems associated with expansive soils are generally not catastrophic, but the effects result in cracked foundations, cracked walls, cracked concrete slabs, cracks around County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 126 windows and doors, as well as jammed windows and doors. Cracks to foundations may lead to additional problems if other catastrophic events were to occur (such as earthquakes). C. Previous Occurrences Each year the Building Department reviews many permit applications to fix problems associated with expansive soils. The number of occurrences is difficult to measure, since property owners may consider the effects of expansive soils to be minor and therefore choose not to do anything about it. D. Probability of Future Events Structures in the County of Santa Cruz will continue to experience problems with expansive soils on a yearly basis as moisture conditions in soils fluctuate. Recent revisions to the Building Codes (2007 California Building Code (CBC) Section 1802 and the 2006 International Building Code) have provided local jurisdictions with new tools to request soils reports for building permits in areas where expansive soils are suspected and have detailed procedures to determine when soils are considered expansive. In addition, Section 1805.8 of the 2007 CBC provides requirements for design for expansive soils. Therefore, over time we expect to see fewer problems with structures due to expansive soils. 12.3.3 Assessing Expansive Soils Vulnerability: Overview 3.3 Assessing Vulnerability: Overview – Requirement §201.6(c)(2)(ii): The risk assessment shall include a description of the jurisdiction’s vulnerability to the hazards described in paragraph (c)(2)(i) of this section. This description shall include an overall summary of each hazard and its impact on the community. A. Overall Summary of Vulnerability to Expansive Soils It is estimated that the County of Santa Cruz has over 13,000 homes built on expansive soils. Typically, the structures that experience problems with expansive soils are older homes, but newer homes (built within the last 15 years) may also experience problems due to expansive soils. The types of problems associated with expansive soils are generally not catastrophic, but the effects result in cracked foundations, cracked walls, cracked concrete slabs, cracks around windows and doors, as well as jammed windows and doors. Cracks to foundations may lead to additional problems if other catastrophic events were to occur (such as earthquakes). 12.3.4 Assessing Expansive Soils Vulnerability: Identifying Structures 3.4 Assessing Vulnerability: Identifying Structures – Requirement §201.6(c)(2)(ii)(A): The plan should describe vulnerability in terms of the types and numbers of existing and future buildings, infrastructure, and critical facilities located in the identified hazard area. A. Types and Numbers of Existing Buildings, Facilities and Infrastructure County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 127 Due to its unique geologic makeup, expansive soils are located mainly in the coastal areas and in agricultural areas in the southern portion of the County. Approximately 16,100 parcels are estimated to be located on expansive soils with 18,462 structures built on these parcels. These areas represent some of the most expensive real estate in the county and the estimated loss in value comes to $2,786,254,269. The majority of the loss in value is in residential areas. See table 12-1 below for specific information on the types of properties located on expansive soils. 12.3.5 Assessing Vulnerability: Estimating Potential Losses 3.5 Assessing Vulnerability: Estimating Potential Losses – Requirement §201.6(c)(2)(ii)(B): The plan should describe vulnerability in terms of an estimate of the potential dollar losses to vulnerable structures identified in paragraph (c)(2)(i)(A) of this section and a description of the methodology used to prepare the estimate. Potential Dollar Losses to Vulnerable Structures While over 13,200 residential parcels have been identified as threatened by expansive soils, there are only 612 structures on these parcels. However, since the majority of these structures are close to the ocean, they represent a loss in value of over $2.25 billion dollars. TABLE 12-1. EXPANSIVE SOILS POTENTIAL LOSS INVENTORY B. Methodology Used to Prepare Estimate Parcel Valuation Valuations of parcels within a hazard area are based on improvement values only as collected by appraisers with the County of Santa Cruz Assessor’s Office. They don’t reflect sale value or County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 128 replacement value. If a parcel intersected a hazard, the entire improvement value of that parcel was used. Population Census population blocks were reduced to center points. If a hazard intersected a center point, that population was counted. 12.3.6 Assessing Vulnerability: Analyzing Development Trends 3.6 Assessing Vulnerability: Analyzing Development Trends – Requirement §201.6(c)(2)(ii)(C): The plan should describe vulnerability in terms of providing a general description of land uses and development trends within the community so that mitigation options can be considered in future land use decisions. A. Description of Land-Uses and Development Trends The County of Santa Cruz has a number of compact urban communities as well as extensive areas of agricultural land and forested hillsides. A number of rural villages and towns are located throughout the County. As dictated by the 1978 Growth Management Ordinance, most new development has occurred within or adjacent to the urban services line (i.e., the boundary point for such infrastructure as water and sewage service). As with most communities, increased housing costs have resulted in the need to provide higher density housing. In Santa Cruz County, all development of this type occurs where urban services are available. Other development is mostly infill or reuse development, and development of existing rural residential properties. Since expansive soils exist both within and outside of the urban services line, mitigation of expansive soils must be looked at on a countywide basis with a focus on the areas of known expansive soils. 12.4.0 Mitigation Strategy 4.0 Mitigation Strategy: Requirement §201.6(c)(3): The plan shall include a mitigation strategy that provides the jurisdiction’s blueprint for reducing the potential losses identified in the risk assessment, based on existing authorities, policies, programs and resources, and its ability to expand on and improve these existing tools. Mitigation strategy includes: Continuation of review of building permit applications to require identification and mitigation of expansive soils as required per the 2007 California Building Code. Pursue an effective public information program and continuing collaborative efforts with the cities, agencies and community organizations to facilitate collaborative efforts in providing expansive soil mapping, information, and education. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 129 12.4.1 Mitigation Goals 4.1 Local Hazard Mitigation Goals – Requirement §201.6(c)(3)(i): The hazard mitigation strategy shall include a description of mitigation goals to reduce or avoid long-term vulnerabilities to the identified hazards. The County of Santa Cruz has developed several expansive soils mitigation goals to decrease the problems associated with expansive soils. Expansive Soils 1 – Education and Awareness Train building plan check staff on expansive soils. Provide public information and education/awareness to all residents of the County concerning expansive soil areas and mitigation efforts. Expansive Soils 2 – Preventative and Implementation Develop and implement activities to protect properties and infrastructure. Expansive Soils 3 – Funding And Partnerships Seek partnerships in funding and resources for future mitigation efforts. 12.4.2 Identification and Analysis of Mitigation Actions 4.2 Identification and Analysis of Mitigation Actions – Requirement §201.6(c)(3)(ii): The mitigation strategy shall include a section that identifies and analyzes a comprehensive range of specific mitigation actions and projects being considered to reduce the effects of each hazard, with particular emphasis on new and existing buildings and infrastructure. Expansive Soils Mitigation Actions The County participates in a number of ongoing mitigation actions to avoid or reduce the effects of expansive soils. These measures are listed under the Part 4 Mitigation Strategy. Actions include: Continue to require soils reports as part of the building permit process (B-13) Develop design criteria for expansive soils properties (C-21) County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 130 CHAPTER 13 — MULTI-HAZARD SUMMARY Any of the hazards that threaten Santa Cruz County could happen in combination with another hazard. In fact, there is a high likelihood that a major earthquake on the San Andreas or other faults would unleash secondary hazards that could be as disastrous to Santa Cruz as the earthquake itself. A reference point for the Bay Area is the devastating fire in 1906 that burned down San Francisco, causing significantly more destruction than the earthquake that sparked it. Earthquake shaking can start fires in numerous ways, such as tipping over appliances with pilot lights or damaging electrical equipment leading to sparks. Ruptured gas lines, both underground and where they connect to houses, or spilled flammable chemicals can cause post-earthquake fires to spread quickly. Efforts to fight fires after an earthquake are often severely hampered by non-functional water systems, damaged electrical systems that are needed to provide energy to pump water, or roads blocked by debris or landslides. These problems coincide with fire personnel being required for search and rescue activities and other disaster response activities. Santa Cruz County may also experience landslides during the next earthquake, particularly if the earthquake occurs during rainy winter months. Small aftershocks could continue to cause slides for weeks after a quake, blocking roads and damaging homes. In addition, the next earthquake may cause significant damage to the county’s water supply (some of which is located in a mountainous slide prone area) and storm drain systems. Although the risk is very low, an earthquake has the potential to cause dam failure. Breaks in the dams, levees and stream culverts could lead to catastrophic flooding in areas that have not seen floodwaters previously. Drought increases the risk of wildfires, and wildfires increase the risk of landslide and flood. When all supporting vegetation is burned away, hills become destabilized and prone to erosion. The charred surface of the earth becomes hard and absorbs less water during rainfall, leading to increased runoff resulting in more rapid coastal erosion. Many mitigation activities reduce risk from more than one hazard. However, there are some mitigation activities that reduce risk from one possible threat while increasing it from another. One example is placing utility lines underground. Underground utilities are less damaged by a major fire than those aboveground. In an earthquake, under-ground utilities in areas prone to landslides or liquefaction are susceptible to damage and are more costly and time-consuming to repair than aboveground utilities. Another example of a mitigation activity with positive and negative impacts is vegetation removal for wildfire risk reduction. Trees and other established plants play a key role in securing hillsides and reducing landslide risk. They also reduce erosion and slow rain runoff time, which reduces flood peaks. It is important to remember all of the implications of any risk reduction steps when planning mitigation activities. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 131 PART 4 — MITIGATION STRATEGY Mitigation Strategy Goals Objectives Actions County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 132 CHAPTER 14 — MITIGATION STRATEGY 4.4.0 MITIGATION STRATEGY 4.0 Mitigation Strategy: Requirement §201.6(c)(3): The plan shall include a mitigation strategy that provides the jurisdiction’s blueprint for reducing the potential losses identified in the risk assessment, based on existing authorities, policies, programs and resources, and its ability to expand on and improve these existing tools. The County of Santa Cruz endeavors to be a disaster-resistant community that can survive and recover from a disaster while preserving the diversity and quality of its natural and built environments. The community strives to offer excellent cultural and community services as well as maintain and improve infrastructure, community safety and emergency preparedness. This Local Hazard Mitigation Plan (LHMP) is a part of this effort. The County of Santa Cruz has developed a range of policies and programs to act as a “blueprint” for the Hazard Mitigation Strategy. Strategies include “everyday operations” that also contribute to reducing the impact of future hazards as well as specific hazard mitigation projects. While County efforts are focused on evaluation and improvement of County owned structures, particularly those identified as critical facilities, the plan also encourages the establishment of standards to encourage private property owners to upgrade the hazard resistance of their own properties. Finally, the County is actively engaged with other local and regional organizations to collaboratively work towards mitigation actions that meet the County of Santa Cruz’s objective of being a disaster resistant community while striving to preserve the quality of its natural and built environments. This plan focuses on mitigation goals and actions, meaning activities that occur prior to a hazard event that reduce or avoid damage when disasters strike. Damage prevention includes structural improvements to existing buildings, land use decisions that will minimize damage and ongoing programs such as vegetation reduction in wildland/urban interface areas. This plan does not include emergency response activities. The County of Santa Cruz has an Emergency Management Plan (EMP) to help coordinate information and resources for disasters or threat of disasters. As a part of the EMP annual training, critical information updates and drills are conducted to protect people and property. However, the EMP does inform this Hazard Mitigation Plan and can be accessed at http://sccounty01.co.santa-cruz.ca.us/oes/plans.htm. Goals Goals are general guidelines that explain what is to be achieved. They are broad-based, policy-type statements, which are long-term, and represent global visions. Goals help define the benefits that the plan is trying to achieve. The success of the LHMP, once implemented, should be measured by the degree to which its goals have been met. The County of Santa Cruz LHMP team held several meetings to review the identified risks and developed goals, objectives and actions based on the risk assessment. Goals which provided the greatest benefit in hazard reduction were identified as primary goals. Additional goals, specifically related to each identified potential hazard are presented under County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 133 each hazard heading. The Local Hazard Mitigation Plan has four primary mitigation goals: 1. Avoid or reduce the potential for life loss, injury and economic damage to Santa Cruz residents from hazard events; 2. Increase the ability of the county government to serve the community during and after hazard events; 3. Protect the unique character, scenic beauty and values in the natural and built environment from being compromised by hazard events; 4. Encourage mitigation activities to increase the disaster resilience of institutions, private companies and systems essential to a functioning County of Santa Cruz. Objectives The LHMP team selected the objectives listed below to meet multiple goals. The objectives serve as a stand-alone measurement of a mitigation action rather than as a subset of a goal. Achievement of the objectives is a measure of the effectiveness of a mitigation strategy. The objectives are also used to help establish priorities. Objectives are defined as short-term aims which, when combined, form a course of action to meet a goal. Unlike goals, objectives are specific and measurable. The County of Santa Cruz Local Hazard Mitigation Team identified this list of objectives: 1. Consider the impacts of hazards on future land use decisions in the County of Santa Cruz by coordinating with other planning mechanisms including the General Plan and land use code developments. 2. Protect and sustain reliable local emergency operations and communication facilities during and after a disaster. 3. Develop new or enhance existing early warning response systems. 4. Seek to enhance emergency response capabilities through improvements to infrastructure and County programs. 5. Seek mitigation projects that provide the highest degree of hazard protection at the least cost. 6. Seek to update information on hazards, vulnerabilities, and mitigation measures by coordinating planning efforts and creating partnerships with appropriate local, state and federal agencies. 7. Seek to implement codes, standards, and policies that will protect life, property and quality of life including environmental, historic and cultural resources from the impacts of hazards within the County of Santa Cruz. 8. Educate the community on preparedness for and mitigation of potential impacts of hazards to the County of Santa Cruz. 9. Encourage retrofit, purchase, or relocation of structures in high hazard areas, including those known to be repetitively damaged. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 134 Identification and Analysis of Mitigation Actions Identification of Actions The Local Hazard Mitigation Goals were enumerated above. In support of those goals, the County of Santa Cruz has identified a number of hazard mitigation actions. This set of actions was developed through an inclusive community process. The LHMP team, with input from the County of Santa Cruz General Plan Update, the Emergency Management Plan, the Capital Improvement Program, the 2005 Urban Water Management Plan and the Santa Cruz Integrated Water Plan as well as other agencies and community members, has selected the following actions as the most beneficial for the County of Santa Cruz. These actions represent the highest priority mitigation actions identified for each hazard or for a multi-hazard event. These mitigation actions have proven effective in reducing or eliminating hazard risk. Each of these actions directly meets an objective or goal listed in the County of Santa Cruz Hazard Mitigation Strategy. These actions are not meant to be exhaustive but rather to inspire thought and provide each department of the County of Santa Cruz with a role in hazard mitigation and a baseline of actions backed by a planning process, consistent with the goals and objectives and within the capabilities of the County. The County departments were not bound to the list of alternatives presented. They were given the opportunity to edit the list. Actions not included in the action plan were eliminated based on the following: • • • • Action is currently outside the scope of the defined priority rankings County’s jurisdiction is not vulnerable to the hazard Action has already been implemented Estimated cost exceeded estimated benefit Prioritization of Actions This Plan promotes 49 action items. The list below summarizes all of the actions, identifies the hazard(s) each one addresses, and indicates the assigned priority level of the action. The actions were prioritized in the same way that they were identified. The team leaders proposed an initial prioritization system, dividing the actions into categories of Very High Priority, High Priority, and Important. County staff, committee and community members were given an opportunity to review these categorizations. Many factors were considered when assigning priorities. First, only those actions with strong community support were given Very High or High priority ratings. Second, those hazards presenting the highest risk to Santa Cruz County were given priority. The loss estimates presented in section five of this Plan show that earthquakes, floods and tsunami’s have the most potential to cause great economic and human losses. Water is essential to the survival of the County so drought and threats to the water system were also ranked as High or very High Priority. Finally, availability of funding (identified in the Capital Improvement Program or other source) was a determining factor in priority determination. Section 201.c.3.iii of Title 44 of the Code of Federal Regulations requires that an action plan describe how actions identified were prioritized. The planning team has developed a prioritization methodology for the action plan that meets the needs of the County while at the same time meeting the requirements of Section 201.6 of Title 44 of the Code of Federal County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 135 Regulations. The mitigation strategies identified were prioritized according to the criteria defined below. Very High Priority A project that meets multiple plan objectives Benefits exceed cost Has strong community support Addresses those hazards presenting the highest risk Funds are identified or potentially available Project can be completed in one to five years once project is funded. High Priority Project meets at least one plan objective Benefits exceed costs Funding has not been secured Project can be completed in one to five years once project is funded Important Project mitigates the risk of a hazard Benefits exceed costs Funding has not been identified and/or timeline for completion is considered longterm (five to ten years) A formal cost benefit analysis has not been done. However, in reviewing the mitigation actions proposed, the costs and benefits of each action were considered under the following rating : Cost Ratings High: Medium: Low: Existing funding levels are not adequate to cover the costs of the proposed project and would require an increase in revenue through an alternative source (e.g. bonds, grants, and fee increases) to implement. The project could be implemented with existing funding but would require a re-apportionment of the budget or a budget amendment, or the cost of the project would have to be spread over multiple years. The project could be funded under the existing budget. The project is part of or can be part of an existing, ongoing program. Benefit Ratings High: Medium: Low: Project will have an immediate impact on the reduction of risk exposure to life and property. Project will have a long-term impact on the reduction of risk exposure to life and property or project will provide an immediate reduction in the risk exposure to property. Long-term benefits of the project are difficult to quantify in the short-term. In recent years, and in response to the 1989 Loma Prieta earthquake, the County of Santa Cruz has made significant progress through efforts to reduce risk in public buildings, fire stations, major municipal facilities and public schools. This plan will continue these efforts and expand them throughout the community. These efforts will protect future generations from the County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 136 devastation of natural hazards experienced by the residents of Santa Cruz County in the past. The County will pursue the implementation of these actions to meet the goals set out above. The Very High and High priority actions will be conducted actively over the next three to five years as funding becomes available. Very High Priority A= Very High Priority Action # Action Hazard A-1 Coordinate preparedness efforts with other agencies and cities within the county Create a policy interpretation for calculating “Substantial Improvement” more effectively in the floodplain Apply for and participate in the Community Rating system to improve floodplain management Evaluate the effectiveness of current policies and ordinances designed to limit storm water runoff and recommend revisions to improve the effectiveness of these policies. Evaluate the effectiveness of current drainage plan requirements Develop a “Stormwater Facilities Master Plan” for Flood control Districts 5 & 6 Implement water conservation efforts to maximize the use of existing water resources Support the development of additional water supplies Promote more effective use of groundwater storage through increased groundwater recharge and conjunctive use among agencies Coordinate a communication system with other agencies and cities, including evacuation operations, for homes and businesses within specific areas Update dam inundation maps Establish and maintain cooperative Flood A-2 A-3 A-4 A-5 A-6 A-7 A-8 A-9 A-10 A-11 A-12 County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 Timeline All Hazards Responsible Department OES Flood Planning Dept. 2009-10 fiscal year Flood Planning Dept. 2010-2011 Flood Planning Dept. 2010-2011 Flood Planning Dept. Dept. of Public Works Dept. of Public Works 2010-2011 Drought Environmental Health Ongoing Drought Environmental Health Environmental Health Ongoing Multihazards OES 2010-2012 Dam failure Wildfires Planning CalFire 2010-2011 2011-2012 Drought Ongoing 2010-2012 Ongoing 137 A-13 A-14 fire protection and fire prevention agreements with other agencies Improve road signs and address marking to increase visibility and reduce response times Enhance support for interoperability communications system with local, state and federal emergency services Wildfires CalFire Ongoing All hazards OES Ongoing Responsible Department Dept. of Public Works Timeline Flood Planning 2010-2015 Wildfire CalFire Ongoing Wildfire CalFire Ongoing Flood Planning Dept. 2010-2015 Flood Planning Dept. Ongoing Flood Dept. of Public Works Ongoing Tsunami OES. Ongoing Tsunami Coastal Erosion Planning Planning Dept. 2011 Ongoing High Priority B = High Priority Action # Action Hazard B-1 Upgrade roadways, sewer, water and other infrastructure to withstand seismic shaking Review and revise California Environmental quality Act (CEQA) Initial Study checklist to ensure storm water runoff is fully mitigated Reduce fire risk in urban/wildland interface (WUI) by advocating use of improved building materials and appropriate code enforcement, including defensible space and fuel reduction programs Maintain adequate Fire Suppression and Prevention staffing levels to meet the needs of the county residents and development trends Seek funding to develop, adopt, update and revise the Geologic Hazards Ordinance Pursue elevation of structures to raise them above the 100-year flood level Continue to enforce requirements for on-site retention of storm water runoff from impervious surfaces for all new development in the Groundwater Recharge Zone and the Water Supply Watershed Zone Management of early warning system Update tsunami maps Protect and preserve the coastline through permit review and continue Earthquake B-2 B-3 B-4 B-5 B-6 B-7 B-8 B-9 B-10 County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 Ongoing 138 B-11 B-12 B-13 to review coastal development for conformance with the County’s Geologic Hazards ordinance Encourage the replacement of existing seawalls with shoreline protection structures which meet current engineering practice Develop an event protocol with the State Division of Safety of Dams Continue to require soils reports as part of the building permit process Coastal Erosion Planning Dept. Ongoing Dam Failure Expansive Soils Planning Dept. 2010-2012 Planning Dept. Ongoing Timeline Important C= Important Action # Action Hazard C-1 Promote seismic safety upgrade of all emergency use and critical structures Require all new and replacement critical structures be designed to standards of the California building Code and County Geologic Hazard Code Train appropriate plan check staff on seismic requirements for structures Encourage zoning in geologically constrained areas that reflect the nature and extent of the seismic hazard Implement additional fire prevention programs through inspections and education Promotion of built-in fire extinguishing systems and fire alarm systems Promote land use planning which will reduce incidence of human caused wildfires especially in very high hazard areas Advocate for creation of secondary road access improvement Continue to inspect and maintain drainage system infrastructure Develop public education materials on flood protection and mitigation by working collaboratively with Earthquake Responsible Department Planning Dept. Earthquake Planning Dept. Ongoing Earthquake Planning Dept. Ongoing Earthquake Planning Dept. Ongoing Wildfire CalFire Ongoing Wildfire CalFire Ongoing Wildfire CalFire Ongoing Wildfire CalFire Ongoing Flood Public Works Ongoing Flood Planning 2010-2015 C-2 C-3 C-4 C-5 C-6 C-7 C-8 C-9 C-10 County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 2011-2012 139 C-11 C-12 C-13 C-14 C-15 C-16 C-17 C-18 C-19 C-20 community groups, nongovernmental organizations and the local media Regulate development in flood zones to optimize preservation of open space through the application of the Geologic Hazards Ordinance and Open Space Preservation policies Limit development and monitor conditions of development and grading permits near natural channels and wetlands to prevent sedimentation. Promote drought planning by the 130 small water systems under county jurisdiction Encourage investigation of tsunami threat to the county and update development regulations based upon the best available information Protect and preserve the coastline and infrastructure through restoration efforts Update dam inundation maps Review dam evaluation files to determine the extent of potential dam failures Continue to require that the County Geologist review development in areas of suspected landsliding and require engineering geology reports when landsliding is identified or suspected Continue to require that an engineering geologist and/or geotechnical engineer investigate the site of any proposed construction near landsliding and require mitigation of landslide hazards before issuing any building or grading permit Continue to require that an engineering geologist and a geotechnical engineer investigate any landslide damage to homes or roadways before repair of the landslide and reuse of the homes or roadways County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 Flood Planning Ongoing Flood Planning and Dept. of Public Works Ongoing Drought Environmental Health Ongoing Tsunami Planning Ongoing Coastal Erosion Planning Dept. and Dept. of Public Works Planning Dept. Ongoing 2010-2015 Planning Dept. 2010-2015 Landslide Planning Dept. Ongoing Landslide Planning Ongoing Landslide Planning Ongoing Dam Failure Dam Failure 140 C-21 C-22 Develop design criteria for areas of known expansive soils Plan for climate change Expansive Soils Multihazards Planning Ongoing Public Health, Planning, OES Ongoing Very High Priority Actions A-1 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority A-2 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority A-3 Proposed Activity Hazard Environmental Concerns Lead dept. Timeline Resources Required Funding source Priority County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 Emergency Preparedness Coordination Continue to participate in the Emergency Management Council by planning, implementing and evaluating pre-event activities including ongoing training for county staff All None Office of Emergency Services Ongoing Staff time General Fund Very High Flood Policy Change Create a policy interpretation for calculating “Substantial Improvement” more effectively n the floodplain Flood None Planning 2010-2015 Staff time General Fund Very High Community Rating System Application Apply for and participate in the Community Rating System to improve floodplain management Flood Riverine and wetlands Planning 2010-2011 Staff Time General Fund Very High 141 A-4 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority A-5 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority A-6 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 Stormwater Policy and Ordinance Evaluation The County shall evaluate the effectiveness of current policies and ordinances designed to limit storm water runoff and flooding and, if needed, recommend revisions to improve effectiveness of these policies and codes Flood Riverine areas and ocean Planning and Public Works 2010-2011 Staff time General Fund Very High Drainage Plan Evaluation The county shall evaluate the effectiveness of the current drainage plan requirements to ensure that storm water runoff from impervious surfaces does not contribute to flooding and, if needed, revise permit conditions of approval Flood Riverine areas and ocean Planning 2010-2011 Staff Time General Fund Very High Stormwater Control Develop a “Stormwater Facilities Master Plan” for Flood control Districts 5 & 6 Flood None Dept. of Public Works 2010-2012 Staff Time Staff Budget Very High 142 A-7 Proposed Activity Hazard Environmental Concerns Lead Dept Timeline Resources Required Funding Source Priority A-8 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority A-9 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 Water Conservation Implement water conservation programs to maximize the use of existing water resources Drought None Environmental Health Ongoing Staff time Staff budget Very High Develop Additional Water Supplies Support the development of additional water supplies and promote more effective use of groundwater storage through increased groundwater recharge and conjunctive use among agencies Drought Agricultural and community concerns Environmental Health 2010-2015 Staff time Staff budget Very high Drought Protection Promote more effective use of groundwater storage through increased groundwater recharge Drought None Environmental Health Ongoing Staff time Staff budget Very High 143 Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority Early Notification\ Warning Systems Coordinate a communication system with other agencies and the cities of Santa Cruz, Watsonville and Capitola, including evacuation operations, for homes and businesses in specific hazard areas Multi-Hazards None OES, CalFire 2010-2015 Staff time Federal and state grants Very High A-11 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority Protection from Dam Failure Update dam inundation maps Dam Failure None Planning 2010-2011 Staff time Staff budget Very High A-12 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority Fire Protection and Prevention Establish and maintain fire protection and prevention agreements with other agencies Wildfire None CalFire, OES Ongoing Staff time Staff budget Very High A-13 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority Reduction of Emergency Response Times Improve road signage visibility and address markings Multi-Hazard None CalFire, Dept. of Public Works Ongoing Staff time Staff budget, general fund Very High A-10 Proposed Activity County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 144 A-14 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 Communications Interoperability Enhance support for interoperability of communications system with local, state and federal emergency services All Hazards None OES, CalFire Ongoing Staff time, new equipment State and Federal grants Very High 145 High Priority Actions B-1 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority B-2 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority B-3 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 Infrastructure Upgrades Upgrade roadways, sewer, water and other infrastructure to withstand seismic shaking Earthquake Geologic and hydrologic Dept. of Public Works Ongoing External funding required, consultants, staff time Federal and State grants, General Fund High Review Stormwater Runoff Regulations Review and revise California Environmental Quality Act (CEQA) Initial Study checklist to ensure that storm water runoff is fully considered and mitigated to the extent possible Flood None Planning 2010-2011 Staff time Staff budget High Wildfire Hazard Abatement Reduce fire risk in wildland/urban interface (WUI) by advocating use of improved building materials and appropriate code enforcement, including defensible space and fuel break and reduction programs Wildfire Stream sedimentation CalFire Ongoing Staff time Staff budget and additional grants High 146 B-4 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding source Priority B-5 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority B-6 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority B-7 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 Adequate Staffing Maintain adequate Fire Suppression and Prevention staffing levels to meet the needs of the county Wildfire None CalFire Ongoing Additional staff Unknown High Geologic Hazards Ordinance Update Seek funds to update and revise the Geologic Hazards Ordinance Multi- Hazard None Planning 2010-2015 Staff time, consultants Federal and State Grants High Elevation of Structures in Floodplain Continue to pursue elevation of structures above level of 100-year flood Flood Sedimentation Planning, OES Ongoing Staff time, technical studies, building materials Federal and State grants, permit application fees High Stormwater Management Continue to enforce requirements for on-site retention of storm water Flood Sedimentation Planning Ongoing Staff time Permit application fees High 147 B-8 Proposed Activity Lead Dept. Timeline Resources Required Funding Sources Priority Management of Early Warning System Define public information process including establishing a reverse 911 system that will notify all homes and businesses within tsunami inundation areas and develop media protocol for evacuation notices Tsunami Water inundation of homes, businesses and resulting losses of life and property, sedimentation, contamination of water channels OES, multiple agencies Ongoing Staff time FEMA Grant funds High B-9 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority Minimize Risk from Tsunami Update tsunami inundation maps Tsunami None Planning 2010-2015 Staff time Staff budget High B-10 Proposed Activity Protect and Preserve Coastline Protect and preserve coastline through permit review process Coastal Erosion Coastal Commission review, community concerns Planning, Dept. of Public Works Ongoing Staff time Staff budget High Hazard Environmental Concerns Hazard Environmental Concerns Lead Dept Timeline Resources Required Funding Source Priority County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 148 B-11 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority B-12 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority B-13 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 Protect Coastline and Infrastructure Encourage replacement of existing seawalls with shoreline protection structures which meet current engineering standards Coastal Erosion Coastal Commission, community concerns Planning, Public Works 2010-2015 Staff time, consultants Federal and State grants High Minimize Risk from Dam Failure Develop an event protocol with the State Division of Safety of Dams Dam Failure Flooding Planning 2010-2015 Staff Time Staff budget High Minimize Risks from Expansive soils Continue to require soils reports as part of the building permit process Expansive soils None Planning Ongoing Staff time Staff budget High 149 Important Actions C-1 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority C-2 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding source Priority C-3 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 Protection of Critical Structures Promote seismic safety upgrade of all emergency use and critical structures Earthquake None Planning Ongoing Staff time and outside consultants Staff budget and unknown grants Important Critical Structural Safety Require all new and replacement critical structures be designed to standards of the California building code and the county’s Geologic Hazards Code Earthquake None Planning Ongoing Staff time Staff budget Important Training for Planning Staff Train appropriate plan check staff on seismic requirements for structures Earthquake None Planning Ongoing Staff time, training consultant Staff budget, unknown grants Important 150 C-4 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding source Priority C-5 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority C-6 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority C-7 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 Seismic Zoning Encourage zoning in geologically constrained areas that reflect the nature and extent of the seismic hazard Earthquake None Planning Ongoing Staff time Staff budget Important Fire Safety and Prevention Programs Implement additional fire prevention programs in schools, institutions, and commercial buildings through inspections and education Wildfire None CalFire Ongoing Staff time Staff budget, grants Important Promote Alarm and Fire Retardant Systems Promote installation, inspection, and testing of built-in fire alarm and sprinkler systems Wildfire None CalFire Ongoing Staff time Permit Fees Important WUI Land Use Planning Promote land use planning to reduce incidence of humancaused wildfires Wildfire None CalFire Ongoing Staff Time Staff budget Important 151 C-8 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding source Priority C-9 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority C-10 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority C-11 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 Emergency Personnel Road Access Advocate for creation of secondary road access improvement Wildfire Code compliance CalFire Ongoing Staff time Staff budget Important Drainage system Infrastructure Integrity Continue to inspect and maintain drainage system infrastructure Flood Sedimentation, property damage Public Works Ongoing Staff time, consultant, repair funds Federal and State grants Important Flood Mitigation Education Develop public education materials by working collaboratively with community groups, non-governmental organizations and the local media Flood None Planning 2010-2015 Staff time Federal and State grants Important Open Space in Flood Zones Regulate development in flood zones to optimize preservation of open space Flood Community concerns Planning Ongoing Staff time Staff budget Important 152 C-12 Proposed Activity Hazard Environmental concerns Lead Dept. Timeline Resources Required Funding Source Priority C-13 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority C-14 Proposed Activity Hazard Environmental concerns Lead Dept. Timeline Resources Required Funding Source Priority C-15 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 Flood Zone Development Regulation Limit development and monitor conditions of development and grading permits near natural channels and wetlands to prevent sedimentation Flood Sedimentation Planning, Public Works Ongoing Staff time Permit fees Important Promote Drought Planning Promote drought planning by the 130 small water systems under county jurisdiction Drought None Environmental Health Ongoing Staff time, consultant Federal and state grants Important New Regulations in Tsunami Inundation Areas Encourage investigation of the tsunami threat to the county and update development regulations based upon this investigation Tsunami None Planning Ongoing Staff time Federal and state grants Important Restoration of Coastline Protect and preserve the coastline and infrastructure through restoration efforts Coastal Erosion Coastal Review Commission, community concerns Public Works Ongoing Staff time, consultant, repair costs unknown Federal and State grants Important 153 C-16 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority Update Inundation Maps Update dam inundation maps Dam Failure Flooding Planning 2010-2015 Staff time Staff budget Important C-17 Proposed Activity Review Dam Hazards Review dam evaluation files to determine the extent of potential dam failures Dam Failure Flooding Planning 2010-2015 Staff time Staff budget state grants Important Hazard Environmental concerns Lead Dept. Timeline Resources Required Funding source Priority C-18 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 Minimize Landslide Risk Continue to require that the county geologist review development in areas of suspected landsliding and require engineering reports when landsliding is identified or suspected Landslide Loss of property and life Planning Ongoing Staff time Staff budget Important 154 C-19 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority C-20 Proposed Activity Landslide Regulations Continue to require that an engineering geologist and/or geotechnical engineer investigate the site of any proposed construction near landsliding and require mitigation of landslide hazards before issuing any building or grading permits Landslide Loss of property and life Planning Ongoing Staff time Staff budget, permit fees Important Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority Landslide Inspections Continue to require that an engineering geologist and/or a geotechnical engineer investigate any landslide damage to homes or roadways before repair of the landslide and reuse of the homes or roadways Landslide Loss of property and life Planning Ongoing Staff time Permit fees Important C-21 Proposed Activity Hazard Environmental Concerns Lead Dept. Timeline Resources Required Funding Source Priority Minimize Damage from Expansive Soils Develop design criteria for areas of known expansive soils Expansive soils None Planning 2010-2015 Staff time, consultant General Fund, Federal and state grants Important County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 155 C-22 Proposed Activity Hazard Environmental concerns Lead Dept. Timeline Resources Requested Funding Source Priority County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 Climate Change Address climate change in Public Health Preparedness Plan Update, General Plan Update and other pertinent plans in order to implement policies and programs to reduce impact of climate change Multi-Hazards Carbon footprint, communicable diseases Public Health, Planning, OES Ongoing Staff time Federal and state grants Important 156 PART 5 – PLAN MAINTENANCE PROCESS Monitoring, Evaluating and Updating the Plan Incorporation into Existing Planning Mechanisms Continued Public Involvement County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 157 CHAPTER 15 —PLAN MAINTENANCE PROCESS 15.5.1 Monitoring, Evaluating and Updating the Plan 5.1 Identification and Analysis of Mitigation Actions – Requirement §201.6(c)(4)(i): The plan maintenance process shall include a section describing the method and schedule of monitoring, evaluating, and updating the mitigation plan within a five-year cycle. Title 44 of the Code of Federal Regulations (CFR) Section 201.6(c)(4)(i) requires a hazard mitigation plan to include a plan maintenance process that includes the following: A section describing the method and schedule of monitoring, evaluating, and updating the mitigation plan within a five-year cycle. A process by which local governments incorporate the requirements of the mitigation plan into other planning mechanisms, such as comprehensive or capital improvement plans, when appropriate. A discussion on how the community will continue public participation in the plan maintenance process. The plan maintenance section of this document details the formal process that will ensure that the County of Santa Cruz hazard mitigation plan (LHMP) remains an active and relevant document. The LHMP maintenance process includes a schedule for monitoring and evaluating the plan annually and producing an updated plan every five years. This chapter also describes how the County will integrate public participation throughout the plan maintenance and implementation process. Finally, this chapter explains how the County intends to incorporate the mitigation strategies outlined in this LHMP into existing planning mechanisms and programs, such as the County General Plan, Capital Improvement Program, as well as building code enforcement and implementation. The LHMP’s format allows the County to review and update sections when new data becomes available. New data can be easily incorporated, resulting in a plan that will remain current and relevant to the County of Santa Cruz. Evaluation of the Plan The minimum task of the ongoing annual hazard mitigation planning team meeting will be the evaluation of the progress of the LHMP and incorporating the actions into other plans. This review will include the following: Summary of any hazard events that occurred during the prior year and their impact on the community. Review of successful mitigation initiatives identified in the LHMP. Brief discussion about why targeted strategies were not completed. Re-evaluation of the action plan to determine if the timeline for identified projects needs to be amended (such as changing a long-term project to a short- term project because of funding availability). Recommendations for new projects. Changes in or potential for new funding options (grant opportunities). Integration of new data such as GIS data and mapping used to inform the Plan. Impact of any other planning programs or initiatives within the County that involve hazard mitigation. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 158 The planning team will create a template to guide the LHMP committee in preparing a progress report. The planning team will also prepare a formal annual report on the progress of the LHMP. This report will be used as follows: Distributed to Department Heads for review. Posted on the County website on the page dedicated to the LHMP. Provided to the local media through a press release. Presented in the form of a board report to the Board of Supervisors. Provided as part of the Community Rating System (CRS) annual re-certification package once the County receives its CRS Rating (currently in progress). The CRS program requires an annual recertification to be submitted every year. To meet this recertification timeline, the planning team will strive to complete this progress report prior to the CRS recertification. Method and Schedule for Updating the Plan within 5 years Section 201.6.(d)(3) of Title 44 of the Code of Federal Regulations requires that local hazard mitigation plans be reviewed, revised if appropriate, and resubmitted for approval in order to remain eligible for benefits awarded under the Disaster Mitigation Act (DMA). The County of Santa Cruz intends to update the LHMP on a five-year cycle from the date of initial plan adoption. This cycle may be accelerated to less than five years based on the following triggers: A Presidential Disaster Declaration that impacts the County of Santa Cruz. A hazard event that causes loss of life. It will not be the intent of this update process to start from scratch and develop a new complete hazard mitigation plan for the County of Santa Cruz. Based on needs identified by the planning team, this update will, at a minimum, include the elements below: The update process will be convened through a committee appointed by the Planning Director and will consist of at least one member of the General Plan Update committee or staff to insure consistency between plans. The hazard risk assessment will be reviewed and updated using best available information and technologies on an annual basis. The evaluation of critical structures and mapping will be updated and improved as funding becomes available. The action plan will be reviewed and revised to account for any actions completed, dropped, or changed and to account for changes in the risk assessment or new county policies identified under other planning mechanisms, as appropriate (such as the General Plan). The draft update will be sent to appropriate agencies for comment. The public will be given an opportunity to comment prior to adoption. The Santa Cruz County Board of Supervisors will adopt the updated plan. Implementation Through Existing Programs The effectiveness of the County’s non-regulatory LHMP depends on the implementation of the plan and incorporation of the outlined action items into existing County plans, policies, and programs. The LHMP includes a range of action items that, if implemented, would reduce loss from hazard events in the County of Santa Cruz. Together, the action items in the LHMP provide the framework for activities that the County can choose to implement over the next five years. The planning team has prioritized the plan’s goals and identified actions that will be implemented (resources permitting) through existing plans, policies, and programs. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 159 The Planning Department has taken on the responsibility for overseeing the plan’s implementation and maintenance through the County’s existing programs. The Director of Planning or designated appointee will assume lead responsibility for facilitating LHMP implementation and maintenance meetings. Although the Planning Department will have primary department responsibility for review, coordination, and promotion, plan implementation and evaluation will be a shared responsibility among all departments identified as lead departments in the mitigation action plan. The Planning Department will continue to work closely with the Emergency Operations Manager to insure consistency in Plans. 15.5.2 Incorporation into Existing Planning Mechanisms 5.2 Identification and Analysis of Mitigation Actions – Requirement §201.6(c)(4)(ii): The plan shall include a process by which local governments incorporate the requirements of the mitigation plan into other planning mechanisms such as the comprehensive or capital improvement plans when appropriate. A. Planning Mechanisms for Incorporating the Requirements of the Plan The information on hazard, risk, vulnerability, and mitigation contained in this plan is based on the best information and technology available at the time the LHMP was prepared. As previously stated, the County’s general plan is considered to be an integral part of this plan. The County, through adoption of its 1994 General Plan (safety element) goals, has planned for the impact of natural hazards. The LHMP process provided the County with the opportunity to review and expand on policies contained within the general plan. The County views the General Plan and the LHMP as complementary planning documents that work together to achieve the ultimate goal of the reduction of risk exposure to the citizens of Santa Cruz. Many of the ongoing recommendations identified in the mitigation strategy are programs recommended by the General Plan, the Urban Water Management Plan, the Capital Improvement Program and other adopted plans. The County will coordinate the recommendations of the LHMP with other planning processes and programs including the following: County Emergency Management Plan Capital Improvement Program County of Santa Cruz Building Codes Community design guidelines Water conservation guidelines Storm Water Management Program Most action items do not need to be implemented through regulation. Instead, these items can be implemented through the creation of educational programs, continued interdepartmental and interagency coordination, or improved public participation. 15.5.3 Continued Public Involvement 5.3 Continued Public Involvement – Requirement §201.6(c)(4)(iii): The plan maintenance process shall include a discussion on how the community will continue public participation in the plan maintenance process. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 160 The public will continue to be apprised of LHMP actions through the County website and by providing copies of the annual progress reports to the media. Copies of the LHMP will be distributed to the Santa Cruz Library System. Upon initiation of the LHMP up-date process, a new public involvement strategy will be initiated based on guidance from the committee. This strategy will be based on the needs and capabilities of the County at the time of the update. At a minimum, this strategy will include the use of local media outlets within the planning area and the County’s website. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 161 END NOTES 1 2 3 County of Santa Cruz General Plan, Chapter 6, pg. 4. National Oceanic and Atmospheric Administration web site: http://www.weather.gov/climate/local California Employment Development Dept., Labor Market Information Division, Current Economic Statistics Group, http://www.calmis.ca.gov/file/Commute-Maps/ScruzCommute.pdf 4 “Santa Cruz County Community Assessment Project, Year 14.” Jan 2009. Applied Survey Research. 11 Aug 2009. http://www.appliedsurveyresearch.org/projects/cap.html#list. 5 Ibid 6 Santa Cruz County Comprehensive Economic Development Strategy, 2008 Annual Update, Applied Development Economics 7 Ibid 8 Seismicity of the United States, 1568-1989 (Revised) by Carl W. Stover and Jerry L. Coffman, U.S. Geological Survey, Professional Paper 1527, U.S. Government Printing Office, Washington: 1993 9 2007 Working Group on California Earthquake Probabilities, 2008, The Uniform California Eathquake Rupture Forecast, Version 2 (UCERF 2): U.S. Geological Survey Open-File Report 2007-1437 and California Geological Survey Special Report 203 [http;//pubs.usgs.gov/of/2007/1437/]. 10 Ibid 11 Estimation of Future Earthquake Losses in California 12 http://www.consrv.ca.gov/CGS/rghm/loss/index.html 13 http://www.codepublishing.com/ca/santacruzcounty/ Headwaters Economics 2008 study, http://www.headwaterseconomics.org/wildfire/ 14 15 2005 Urban Water Management Plan, City of Santa Cruz, February 2006 (page 5-3) 16 Actual period of record for e gauge on the San Lorenzo River began in 1936. Synthesized flow records generated for earlier modeling studies were used to extend the record back to 1921 17 One acre-foot equals 325,851 gallons; 3.07 acre-feet equals one million gallons 18 2005 Urban Water Management Plan, City of Santa Cruz, February 2006, Santa Cruz Integrated Water Plan Final Program EIR 19 Lorrie and Alan Flint, USGS, California Water Science Center, “Climate Change & Hydrology in Watersheds of Santa Cruz County”, Power Point presentation, 2009 20 City of Santa Cruz Urban Water Management Plan, February 2006, page2-7 21 Ibid 22 California Coastal Commission ReCAP Pilot Project Findings and Recommendations: Monterey Bay Region 23 Evaluation of Erosion Hazards – Heinz Center Coastal Erosion Mapping and Management – Journal of Coastal Research 24 Draft Review of California Coastal Erosion Planning and Response: A Strategy for Action, Gary D. Nichols, California Resources Agency, March 2003 25 California Coastal Commission ReCAP Pilot Project Findings and Recommendations: Monterey Bay Region 26 County of Santa Cruz General Plan, http://www.sccoplanning.com/html/policy/general_plan.htm 27 USGS Open File 97-745 C, Sheet 9 of 11 County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 162 28 County of Santa Cruz General Plan, http://www.sccoplanning.com/html/policy/general_plan.htm. County of Santa Cruz Local Hazard Mitigation Plan 2010-2015 163