Abstract

Sea level rise increases community risks from erosion, wave flooding, and tides. Current management typically protects existing development and infrastructure with coastal armoring. These practices ignore long-term impacts to public trust coastal recreation and natural ecosystems. This adaptation framework models physical responses to the public beach and private upland for each adaptation strategy over time, linking physical changes in widths to damages, economic costs, and benefits from beach recreation and nature using low-lying Imperial Beach, California, as a case study. Available coastal hazard models identified community vulnerabilities, and local risk communication engagement prioritized five adaptation approaches—armoring, nourishment, living shorelines, groins, and managed retreat. This framework innovates using replacement cost as a proxy for ecosystem services normally not valued and examines a managed retreat policy approach using a public buyout and rent-back option. Specific methods and economic values used in the analysis need more research and innovation, but the framework provides a scalable methodology to guide coastal adaptation planning everywhere. Case study results suggest that coastal armoring provides the least public benefits over time. Living shoreline approaches show greater public benefits, while managed retreat, implemented sooner, provides the best long-term adaptation strategy to protect community identity and public trust resources.

Authored by:

David Revell, Integral Consulting Inc., Santa Cruz, CA 95060, USA; drevell@integral-corp.com
Phil King, Economics Department, San Francisco State University, San Francisco, CA 94132, USA; pgking@sfsu.edu
Jeff Giliam, Economics Department, George Mason University, Fairfax, VA 22030, USA; jeffrey.giliam@gmail.com
Juliano Calil, Middlebury Institute of International Studies, Monterey, CA 93940, USA; juliano.calil@gmail.com
Sarah Jenkins, Economics Department, University of the Pacific, Stockton, CA 95211, USA; sjnkns97@gmail.com
Chris Helmer and Jim Nakagawa, City of Imperial Beach, San Diego, CA 91932, USA; chelmer@imperialbeachca.gov (C.H.);
jnakagawa@me.com (J.N.)
Alex Snyder, U.S. Geological Survey, Santa Cruz, CA 95060, USA; agsnyder@usgs.gov
Joe Ellis, Marathon Construction Corporation, Lakeside, CA 92040, USA; Joe@marathonsd.com
Matt Jamieson, Integral Consulting, Santa Cruz, CA 95060, USA; mjamieson@integral-corp.com

Keywords: sea level rise adaptation; vulnerability assessment; adaptation planning; cost–benefit analysis; public trust; ecological and recreation valuation; risk communication; living shoreline; adaptation pathways; coastal resilience; coastal hazards; coastal management.