Abstract
Climate change now affects almost every facet of California’s natural and built environment, and sea level rise will have widespread adverse consequences for California’s coastal resources as well as residential development. Threats to residential development will also mean that shoreline structures, including seawalls, revetments, and emergency measures will continue to be proposed to protect existing development. Where shoreline protection like seawalls is the answer to sea level rise, one consequence is the “coastal squeeze”—the incremental loss of recreational beach area and shoreline habitats in front of immovable shoreline structures. The California Coastal Act provides for the protection of existing development from shoreline hazards but also requires that new development (including redevelopment of existing structures) protect public access and recreation, sensitive biological and visual resources, and other coastal resources. While California has a robust planning and regulatory governance framework for addressing coastal hazards, accelerating sea level rise presents a vexing planning challenge. Local governments need policy guidance on providing for future residential development and adaptation to changing conditions while assuring the maximum protection and enhancement of the coastal resource values that lie between shoreline residential areas and the sea. We propose a typology, or systematic classification of types that have similar characteristics, to describe the residential development and hazard conditions found along California’s coastline. This typology is useful for guiding the application of alternative statewide sea level rise adaptation policies that are consistent with the Coastal Act. Through six case studies, we demonstrate how six different development contexts illustrate planning challenges related to issues like redevelopment rules, shoreline protection, bluff edge setbacks, and monitoring trigger conditions. While the complexity of development patterns, local geomorphology, and changing ocean conditions do not lend themselves toward any single “silver bullet” for addressing sea level rise, understanding the similarities and differences across communities will support better proactive planning for sea level rise resilience, and promote sharing of knowledge and experiences along the coast in the coming decades.