California Institute for Energy and Environment (CIEE)

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.