Sea level is projected to rise at least 16 inches along the California coast by 2050, with a 55-inch rise predicted by 2100. The primary impacts from sea level rise are increases in flooding and erosion. Sea level rise will expand the area vulnerable to flooding during major storms, as well as in the rare but catastrophic event of a major tsunami. 

The term 100-year flood is used as a standard for planning, insurance, and environmental analysis.  People, infrastructure, and property are already located in areas vulnerable to flooding from a 100-year event. Sea level rise will cause more frequent—and more damaging—floods to those already at risk and will increase the size of the coastal floodplain, placing new areas at risk to flooding.