Initial Groundwater Basin Prioritization under the Sustainable Groundwater Management (SGM) Act

The Sustainable Groundwater Management Act revised the Water Code to direct the Department of Water Resources (DWR) to develop the initial groundwater basin priority by January 31, 2015. DWR has concluded that the basin prioritization finalized in June 2014 under the California Statewide Groundwater Elevation Monitoring (CASGEM) program will be the initial prioritization when the SGM Act goes into effect on January 1, 2015. The basin prioritization results are posted on the CASGEM website at

GW Basin Priority The SGM Act applies to the 127 High and Medium priority groundwater basins, which account for approximately 96 percent of groundwater use in California.

DWR has determined that data is not readily available to allow reprioritization based on adverse impacts from local habitat and local streamflows prior to January 31, 2015.  DWR will immediately begin to compile the habitat and streamflow data and develop a revised process to consider new information. The groundwater basin prioritization could change at a later date for some basins due to the consideration of impacts from local habitat and local streamflows in addition to potential changes to basin boundaries based on improved geologic information, correcting errors in the dataset, and requests from local agencies.  However, any changes to basin priorities will not be officially changed until after the Bulletin 118 alluvial groundwater basin boundaries are updated in 2016.  The basin prioritization update process will include public meetings or workshops to solicit data not available to DWR and input on the process.

The June 2014 Final Statewide basin prioritization results are compiled into a summary table. This list is organized by priority and includes the basin name, number, total score, Hydrologic Region, and DWR Region. More detailed information, associated maps, and description of the process are available here.