California Statewide Groundwater Elevation Monitoring (CASGEM)

Since 2009, the California Statewide Groundwater Elevation Monitoring (CASGEM) Program has tracked seasonal and long-term groundwater elevation trends in groundwater basins and non-basin areas statewide. 

The Program’s mission is to establish a permanent, locally-managed program of regular and systematic monitoring in all of California's alluvial groundwater basins. This statewide groundwater elevation monitoring continues to act as a tool to help achieve the goals set out under the Sustainable Groundwater Management Act (SGMA).

Senate Bill x7-6, passed by the legislature in 2009, established collaboration between local monitoring parties and DWR to collect statewide groundwater elevations, to be made available to the public. In response to the law, we developed the CASGEM program and the CASGEM Online System. 

Collecting and evaluating these groundwater data on a statewide scale is a fundamental step toward improving management of California's groundwater resources. The CASGEM program relies and builds upon the many previously established local long-term groundwater monitoring and management programs. Our role is to coordinate the CASGEM program, to work cooperatively with local entities, and to maintain the collected elevation data in a readily and widely available public database.

The CASGEM Online System Has Moved to the SGMA Portal!

DWR is pleased to announce that on July 1, 2026, the California Statewide Groundwater Elevation Monitoring (CASGEM) Program's Online System became fully integrated with the Sustainable Groundwater Management Act (SGMA) Portal's Monitoring Network Module (MNM) and the existing CASGEM Online System has been closed.

As previously announced, this integration will streamline groundwater elevation data management and reporting by consolidating data submission into a single platform—the SGMA Portal's MNM. This enhancement will provide a more unified and efficient experience for local agencies, stakeholders, and the public. You can access the SGMA Portal here.

Designated CASGEM Monitoring Entities who manage CASGEM Notifications can find step-by-step instructions, including account creation, in the CASGEM Notification Submodule User Manual.

CASGEM Online System users who submit voluntary groundwater elevation measurements to DWR can also find step-by-step instructions in the Voluntary Monitoring Submodule User Manual.