California Statewide Groundwater Elevation Monitoring (CASGEM) Program

The CASGEM Program tracks seasonal and long-term groundwater elevation trends in groundwater basins statewide.

2015 CASGEM Status Report to the Legislature and the Governor
Posted on 07/12/2016

DWR has completed the 2015 CASGEM Status Report, prepared for the Governor and the Legislature as required by the Water Code (§10920 et seq.). This report describes the significant number of CASGEM Program accomplishments achieved during calendar years 2012 through 2015. This report is the second in a series of CASGEM Program status reports that DWR will provide to the Governor and the Legislature. The first status report covers calendar years 2010 and 2011.

CASGEM Online System

Public users can view Monitoring Entities, monitored groundwater basins and wells, and groundwater elevation data, through reports, search tools, and GIS viewing by accessing the Public User Login to the Online System.

Current or prospective Monitoring Entities can notify DWR of their intent to become a Monitoring Entity, manage existing Notification information, and submit groundwater elevation data through the Monitoring Entity Login to the Online System.

Overview of CASGEM

On November 4, 2009 the State Legislature amended the Water Code with SBx7-6, which mandates a statewide groundwater elevation monitoring program to track seasonal and long-term trends in groundwater elevations in California's groundwater basins. To achieve that goal, the amendment requires collaboration between local monitoring entities and Department of Water Resources (DWR) to collect groundwater elevation data. Collection and evaluation of such data on a statewide scale is an important fundamental step toward improving management of California's groundwater resources.

In accordance with this amendment to the Water Code, DWR developed the California Statewide Groundwater Elevation Monitoring (CASGEM) program. The intent of the CASGEM program is to establish a permanent, locally-managed program of regular and systematic monitoring in all of California's alluvial groundwater basins. The CASGEM program will rely and build on the many, established local long-term groundwater monitoring and management programs. DWR's 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. DWR will also continue its current network of groundwater monitoring as funding allows.

The law anticipates that the monitoring of groundwater elevations required by the enacted legislation will be done by local entities. The law requires local entities to notify DWR in writing by January 1, 2011 if the local agency or party seeks to assume groundwater monitoring functions in accordance with the law.

Overview of SBX7 6

In 2009, the Legislature passed SBX7 6, which establishes, for the first time in California, collaboration between local monitoring parties and DWR to collect groundwater elevations statewide and that this information be made available to the public.


On or before January 1, 2011:
Parties seeking to assume groundwater elevation monitoring functions must notify DWR
(WC section 10928)

On or before January 1, 2012:
Monitoring Entities shall begin reporting seasonal groundwater elevation measurements
(WC section 10932)

SBX7 6 provides that:

  • Local parties may assume responsibility for monitoring and reporting groundwater elevations.
  • DWR work cooperatively with local Monitoring Entities to achieve monitoring programs that demonstrate seasonal and long-term trends in groundwater elevations.
  • DWR accept and review prospective Monitoring Entity submittals, then determine the designated Monitoring Entity, notify the Monitoring Entity and make that information available to the public.
  • DWR perform groundwater elevation monitoring in basins where no local party has agreed to perform the monitoring functions.
  • If local parties (for example, counties) do not volunteer to perform the groundwater monitoring functions, and DWR assumes those functions, then those parties become ineligible for water grants or loans from the state.

For text of the chaptered legislation, please visit the official California Legislative Information website.