Griggs, G. and Patsch, K., 2019. The protection/hardening of California's coast: Times are changing. Journal of Coastal Research, 35(5), 1051–1061. Coconut Creek (Florida), ISSN 0749-0208.
Coastal hazards involve the interaction or effects of natural coastal processes on shoreline development, infrastructure, and human activities. Future sea-level rise will affect California's coastal development and infrastructure through both flooding of low-lying areas and erosion of cliffs, bluffs, and dunes. The global rate of sea-level rise is increasing and many low-lying developed shoreline areas are already experiencing flooding at extreme high tides, particularly during periods of large storm waves. The combined effects of short-term extreme wave and tide events and the global rate of sea level increase will present greater risks in the near future for coastal California. Protecting private development and public infrastructure along shorelines has become a pressing issue for many coastal communities and the state, with a limited number of management options, each with their own costs, benefits, and effects. These options include: do nothing, beach nourishment, hard armoring structures, living or green shorelines, and managed retreat or relocation. Hard armoring structures such as seawalls and revetments have been the typical historical response to coastal erosion, and in 1971, just 2.5% of California's entire 1760-km shoreline was armored. By 2018, armor totals reached 13.9% of the entire state's coastline, a 5.5-fold increase over 47 years. None of the past or present efforts to protect shoreline development and infrastructure from coastal storm damage and shoreline erosion will be effective over the long term with rising sea levels. A growing awareness of the cumulative effects of armoring the shoreline has led the California Coastal Commission to take an increasingly critical look at any new proposals for coastal armoring.