Senate Bill 5
(SB 5), which was enacted in 2007, authorized the California Department of Water Resources (DWR) to develop the Best Available Maps (BAM) displaying 100- and 200-year floodplains for areas located within the Sacramento-San Joaquin (SAC-SJ) Valley watershed. SB 5 requires that these maps contain the best available information on flood hazards and be provided to cities and counties in the SAC-SJ Valley watershed. This effort was completed by DWR in 2008.
DWR has expanded the BAM to cover all counties in the State and to include 500-year floodplains. The 100-, 200-, and 500-year floodplains are displayed on this web viewer. The web viewer allows users to view a particular area and identify their potential flood hazards. The following is a comprehensive list of the floodplains that are displayed on the web viewer and may be updated periodically.