COUNTY OF VENTURA RESOURCE MANAGEMENT AGENCY | PLANNING DIVISION August 30, 2019 County of Ventura Resource Management Agency - Planning Division 800 South Victoria Ave Ventura, CA 93009 Acknowledgements ACKNOWLEDGEMENTS This report was prepared by the following individuals: County of Ventura ▪ Tricia Maier, Long-Range Planning Manager ▪ Aaron Engstrom, Senior Planner ▪ Abigail Convey, Planning Biologist ▪ Angela Kim, CivicSpark Climate Fellow Revell Coastal, LLC ▪ David L. Revell, PhD, Project Director ▪ Phil King, PhD, Lead Economist ▪ Matt Jamieson, MFA, GIS Analyst and Coastal Scientist ▪ Jeffrey Giliam, Economist The sea level rise models used to compile this report were developed by the following organizations: 2012 Coastal Resilience Ventura Model: ▪ The Nature Conservancy, California Chapter ▪ County of Ventura ▪ Environmental Science Associates (ESA) 2017 Coastal Storm Modeling System (CoSMoS v3.0): ▪ United States Geological Survey ▪ California Coastal Conservancy County of Ventura August 30, 2019 VC Resilient Coastal Adaptation Project i Adaptation Strategies Report Acknowledgements This page was intentionally left blank. County of Ventura August 30, 2019 VC Resilient Coastal Adaptation Project ii Adaptation Strategies Report Contents CONTENTS Figure ACKNOWLEDGEMENTS ................................................................................................................................. i ACRONYMS/ABBREVIATIONS ...................................................................................................................... v DEFINITIONS ................................................................................................................................................ vi REPORT, MAP, AND DATA DISCLAIMER ................................................................................................... viii 1. INTRODUCTION ...................................................................................................................................... 1-1 1.1 Advanced Planning for Sea Level Rise ........................................................................................ 1-2 1.2 Report Goals and Deliverables ................................................................................................... 1-3 1.3 Adaptation Planning Guidance .................................................................................................. 1-4 2. EXISTING SETTING AND POTENTIAL IMPACTS ....................................................................................... 2-1 2.1 North Coast ................................................................................................................................ 2-3 Existing Conditions and Community Narrative .................................................................................. 2-3 Summary of Vulnerabilities ................................................................................................................ 2-5 Services into the Future ..................................................................................................................... 2-8 2.2 Central Coast ............................................................................................................................ 2-10 Existing Conditions and Community Narrative ................................................................................ 2-10 Summary of Vulnerabilities .............................................................................................................. 2-11 Services into the Future ................................................................................................................... 2-16 2.3 South Coast .............................................................................................................................. 2-18 Existing Conditions and Community Narrative ................................................................................ 2-18 Summary of Vulnerabilities .............................................................................................................. 2-20 Services into the Future ................................................................................................................... 2-26 3. ADAPTATION PLANNING ........................................................................................................................ 3-1 Impacts ............................................................................................................................................... 3-1 Cumulative Effects ............................................................................................................................. 3-2 Long-Term Adaptive Capacity ............................................................................................................ 3-4 Protect, Accommodate, and Retreat: The Approaches to Coastal Adaptation ................................. 3-5 3.1 Adaptation Strategies for County of Ventura ............................................................................ 3-6 County-Wide Adaptation Strategies .................................................................................................. 3-7 North Coast ...................................................................................................................................... 3-22 Central Coast .................................................................................................................................... 3-27 County of Ventura August 30, 2019 VC Resilient Coastal Adaptation Project iii Adaptation Strategies Report Contents South Coast ...................................................................................................................................... 3-33 3.2 Adaptation Pathways ............................................................................................................... 3-40 Adaptation Pathway Case Studies ................................................................................................... 3-40 APPENDIX A. NATURAL RESOURCES ADAPTATION MATRIX ..................................................................... A-1 APPENDIX B. ECONOMIC ANALYSIS of ADAPTATION STRATEGY CASE STUDIES ....................................... B-1 B.1 Native Dune Construction ................................................................................................................ B-1 B.2 Stormwater System Improvements ................................................................................................. B-9 B.3 Replacement of the Revetment with a Seawall Along the Rincon Parkway.................................. B-11 B.4 Sediment Retention through Cobble-Based Groins at Hobson and Faria County Parks, and the Rincon Parkway ................................................................................................................................................ B-15 B.5 Limitations of the Study ................................................................................................................. B-17 B.6 Conclusion ...................................................................................................................................... B-17 County of Ventura August 30, 2019 VC Resilient Coastal Adaptation Project iv Adaptation Strategies Report Acronyms/Abbreviations ACRONYMS/ABBREVIATIONS BEACON Beach Erosion Authority for Clean Oceans and Nourishment Coastal Resilience Coastal Resilience Ventura Project (The Nature Conservancy, County of Model Ventura, and Environmental Science Associates, 2012) CoSMoS Coastal Storm Modeling System of the United States Geologic Survey County County of Ventura FEMA Federal Emergency Management Agency LCP Local Coastal Program OPC Ocean Protection Council Report 2019 VC Resilient Coastal Adaptation Project Sea Level Rise Adaptation Strategies Report SLR Sea Level Rise USFWS United States Fish and Wildlife Service County of Ventura August 30, 2019 VC Resilient Coastal Adaptation Project v Adaptation Strategies Report Definitions DEFINITIONS The following terms are defined for the purpose of use in this Report: 1% Annual Chance Storm: often called a 100-year storm event, it is an exceptionally large storm with a 1% chance of occurring in any given year. It is the basis for the FEMA regulatory flood maps. In rivers it is based on streamflow, and on the open coast it is based on wave run up. Adaptation: anticipating the adverse effects of climate change and taking appropriate action to prevent or minimize the vulnerabilities. Adaptation Pathway: an adaptation pathway is a planning approach addressing the uncertainty and challenges of climate change decision-making. It enables consideration of multiple possible futures and allows analysis/exploration of the robustness and flexibility of various options across those multiple futures. Adaptive Management: a process of iteratively planning, implementing, and modifying strategies for managing resources in the face of uncertainty and change. Adaptive management involves adjusting approaches in response to observations of their effect and changes in the system brought on by resulting feedback effects and other variables. Adaptive Capacity: the ability of a system to respond to climate change (including climate variability and extremes), to moderate potential damage, to take advantage of opportunities, and to cope with the consequences. Base Flood Elevation: reflects the height (in feet) above sea level that flood water is predicted to rise during