Santa Barbara Sea Level Rise Study (Griggs & Russell 2012)
Total Page:16
File Type:pdf, Size:1020Kb
Appendix B Santa Barbara sea level rise study (Griggs & Russell 2012) Santa Barbara Climate Action Plan –Vol. 2 Appendices June 2012 Public Review Draft Santa Barbara Climate Action Plan –Vol. 2 Appendices June 2012 Public Review Draft Public Interest Energy Research (PIER) Program White Paper CITY OF SANTA BARBARA SEA-LEVEL RISE VULNERABILITY STUDY A White Paper from the California Energy Commission’s California Climate Change Center A White Paper from the California Energy Commission’s California Climate Change Center Prepared for: California Energy Commission Prepared by: University of California, Santa Cruz FEBRUARY 2012 CEC-500-2012-XXX Gary Griggs Nicole Russell University of California, Santa Cruz DISCLAIMER This paper was prepared as the result of work sponsored by the California Energy Commission. It does not necessarily represent the views of the Energy Commission, its employees or the State of California. The Energy Commission, the State of California, its employees, contractors and subcontractors make no warrant, express or implied, and assume no legal liability for the information in this paper; nor does any party represent that the uses of this information will not infringe upon privately owned rights. This paper has not been approved or disapproved by the California Energy Commission nor has the California Energy Commission passed upon the accuracy or adequacy of the information in this paper. PREFACE The California Energy Commission’s Public Interest Energy Research (PIER) Program supports public interest energy research and development that will help improve the quality of life in California by bringing environmentally safe, affordable, and reliable energy services and products to the marketplace. The PIER Program conducts public interest research, development, and demonstration (RD&D) projects to benefit California. The PIER Program strives to conduct the most promising public interest energy research by partnering with RD&D entities, including individuals, businesses, utilities, and public or private research institutions. PIER funding efforts are focused on the following RD&D program areas: Buildings End-Use Energy Efficiency Energy Innovations Small Grants Energy-Related Environmental Research Energy Systems Integration Environmentally Preferred Advanced Generation Industrial/Agricultural/Water End-Use Energy Efficiency Renewable Energy Technologies Transportation In 2003, the California Energy Commission’s PIER Program established the California Climate Change Center to document climate change research relevant to the states. This center is a virtual organization with core research activities at Scripps Institution of Oceanography and the University of California, Berkeley, complemented by efforts at other research institutions. Priority research areas defined in PIER’s Climate Change Research Plan are: monitoring, analysis, and modeling of climate; improved methods to estimate greenhouse gas emissions; analysis of options to reduce greenhouse gas emissions; and impacts and adaptation studies. For more information on the PIER Program, please visit the Energy Commission’s website http://www.energy.ca.gov/research/index.html or contract the Energy Commission at (916) 327-1551. i ABSTRACT Cliff and bluff erosion, flooding of low-lying areas, and damage to shoreline infrastructure and development will continue to affect California’s coastal communities in the decades ahead. Depending upon the rate of future sea-level rise, changes in wave energy, and coastal storm intensity and frequency, these hazards will be likely become more severe, with increasing risks to coastal communities. This study assesses the vulnerability of the City of Santa Barbara to future sea-level rise and related coastal hazards (by 2050 and 2100) based upon past events, shoreline topography, and exposure to sea-level rise and wave attack. It also evaluates the likely impacts of coastal hazards to specific areas of the City, analyzes their risks and the City’s ability to respond, and recommends potential adaptation responses. By 2050, the risk of wave damage to shoreline development and infrastructure in Santa Barbara will be high. Options are limited and adaptive capacity will be moderate, with retreat being the most viable long-term option. By 2100, the risk will become very high. By 2050, flooding and inundation of low-lying coastal areas will present a moderate risk to the City by 2050, which will have a moderate capacity for adaptation. If the high sea levels projected by the State occur, this risk will become very high, and adaptive capacity will become low by 2100. Cliff erosion has been taking place for decades, and as this process continues or increases, additional public and private property in the Mesa area will be threatened. The risk of increased cliff erosion will be moderate by 2050 and very high by 2100. Because armoring is ineffective here and retreat necessitates the relocation of structures, adaptive capacity will be low. Inundation of beaches presents a low threat to the City by 2050 but a high threat by 2100. The City faces a dilemma: protect oceanfront development and infrastructure or remove barriers and let beaches migrate inland. By 2100 structures will have to be moved if beaches are to be maintained. Keywords: adaptation, adaptive capacity, climate change, coastal cliff erosion, coastal hazards, coastal storm damage, flooding, inundation, risk assessment, sea-level rise, vulnerability assessment, wave climate Please use the following citation for this paper: Griggs, Gary, and Nicole L. Russell (University of California, Santa Cruz). 2012. City of Santa Barbara Sea-Level Rise Vulnerability Study. California Energy Commission. Publication number: CEC-500-2012-XXX. ii TABLE OF CONTENTS Objectives ..................................................................................................................................... 1 Section 1: An Introduction to Climate Change and Sea-Level Rise .................................. 2 1.1 Awareness and Attitudes About Climate Change and Sea-Level Rise Among Planners and Managers ......................................................................................................................................... 6 1.2 Recent Rates of Sea-Level Rise in California .......................................................................... 7 1.3 Projecting Sea-Level Rise for the Decades Ahead ............................................................... 10 Section 2: Vulnerability Assessment of the Santa Barbara Coastline to Future Sea- Level Rise and Related Coastal Hazards .............................................................................. 12 2.1 Sea-Level Rise ........................................................................................................................... 14 2.1.1 The Record of Historic Sea Level Change along the Santa Barbara Coastline ........ 15 2.1.2 Future Sea-Level Rise Projections and Their Effects ................................................... 17 2.2 Coastal Storm Damage and Erosion ...................................................................................... 18 2.3 Cliff Retreat ............................................................................................................................... 20 2.4 Shoreline or Beach Retreat ...................................................................................................... 28 Box Essay: Effects of the 1983 Winter on Santa Barbara, California ......................................... 31 Savage Surf Slams County Coast - ................................................................................................. 31 2.5 Runoff and Flooding ................................................................................................................ 32 2.5.1 The Santa Barbara Airport .............................................................................................. 41 2.6 Tsunami Hazards ..................................................................................................................... 46 Section 3: Assessing Risks from Sea-Level Rise and Associated Coastal Hazards to the City of Santa Barbara ......................................................................................................... 48 3.1 Introduction .............................................................................................................................. 48 3.2 Assumptions ............................................................................................................................. 49 3.3 Increase in Rates of Cliff Erosion ........................................................................................... 49 3.4 Passive Erosion or Inundation of Beaches ............................................................................ 53 3.5 Wave Damage to Shoreline Development and Infrastructure .......................................... 55 3.6 Flooding and Inundation of Low-lying Coastal Areas ....................................................... 55 3.6.1 Santa Barbara Airport ...................................................................................................... 56 Section 4: Adaptation to Sea-Level Rise ............................................................................... 57 3.1 Principles for Adaptation and Adaptive Capacity .............................................................. 58 3.2 Progress on Adaptation Actions at the State Level ............................................................