California Statewide Groundwater Elevation Monitoring (CASGEM)
Authorized by SBX7 6, enacted in November 2009

CASGEM Groundwater Basin Prioritization information is posted here.

CASGEM Status Report to the Legislature and the Governor Is Now Available

DWR has completed the 2012 CASGEM Status Report, prepared for the Governor and the Legislature as required by the Water Code (§10920 et seq.). The report outlines the background of the CASGEM Program and describes the first two years of implementation. This report is the first in a series of periodic reports on the CASGEM Program that DWR will provide to the Governor and the Legislature.  Subsequent reports will be provided every five years beginning in 2015.

CASGEM Online System Is Now Available

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.

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.

Attention CASGEM Online System Users: CASGEM will undergo routine maintenance on May 25, 2016, from 5:00 pm to 7:00 pm. There will be an interruption in website access during this time. We apologize for any inconvenience this may cause.

Attention CASGEM Online System Users:

A third deployment of bug-fixes and system feature enhancements was completed for the CASGEM Online System on May 5, 2016. Descriptions of the deployed fixes and enhancements are described in Release 3 Notes (also posted on the Monitoring Entity Online System Portal)

This third deployment includes data validation enhancements that require a modification to the Excel batch upload template for groundwater elevation data submittal. This modification includes the addition of a field to the Excel spreadsheet labeled as 'RP to WS'.

Some users have received error messages when using the new batch upload template to upload data to the online system. In response, DWR has performed extensive troubleshooting on the template and has discovered an error in the coding related to the following validation rule described in the release notes:

“Reading at WS should not have a value entered if the Measurement Method code used is ES (Electric Sounder), AS (Acoustic or Sonic Sounder), PG (Pressure Gauge), or TR (Electronic Pressure Transducer). An error message will be generated and the batch upload will fail if there is a value in the “Reading at WS” column and one of these Measurement Methods has been used. Measurement Method codes that will allow a value in the Reading at WS field are ST (Steel Tape), OTH (Other), or UKN (Unknown).”

Until further notice when this problem is resolved, please do not attempt to upload groundwater elevation monitoring data to the CASGEM Online System.

We anticipate that this problem will be resolved within approximately two weeks and will notify monitoring entities and cooperators accordingly. We will also post a revised message on this web site announcing when batch data uploading can be resumed. Revisions to the release notes will also be posted at that time.

Once this issue is resolved, users experiencing other errors that they believe are being caused by changes to the data upload template should review the release notes and ensure that their data are in conformance with the new validation rules. DWR CASGEM staff will be available and happy to assist with troubleshooting any unresolvable errors.

We apologize for any inconvenience this has caused. As always, we thank you for your continued interest and participation in in the CASGEM Program.

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.