Groundwater Info Center
Monitoring and Data Collection

The collection of groundwater data and other related data is typically guided by structured monitoring programs. In other words, groundwater data and monitoring go hand-in-hand. Data collection, through monitoring, and subsequent data analysis are critical components for effective management of groundwater. Properly designed and well managed data programs provide foundational data useful in a broad spectrum of reporting needs. Science based analysis of complex issues may require the analysis of multiple datasets, such as the study of groundwater and surface water interaction, or evaluating the impact of water quality on water quality.

Statewide there is a broad spectrum of agencies that collect a wide variety of data and DWR has many robust data collection programs. For groundwater studies and reports, DWR relies on groundwater level, groundwater quality, and land subsidence data collected by DWR staff as well as other federal, state, and local entities.

Groundwater Data

WDL contains hydrologic data (groundwater level data and some groundwater quality data) for over 35,000 wells California. The data is collected by DWR Region Offices and dozens of local and federal cooperators. WDL's easy on-line data retrieval provides information quickly!

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. For more information, visit DWR's CASGEM website.

DWR and cooperating federal, state and local agencies, measure groundwater levels in thousands of monitoring wells throughout the state. Groundwater level measurements, collected for a wide variety of purposes and programs are accessible online from the DWR Water Data Library. The CASGEM OS Website allows users to access and upload CASGEM and Voluntary water level measurement data.
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California's future water supply depends on groundwater and its water quality must be monitored and protected. Groundwater basins across the state are assessed by DWR Regions and other cooperators to determine water quality, identify areas of poor quality, and to track long-term changes in groundwater quality.
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Inelastic land subsidence caused by groundwater extraction is a major problem in California and is exacerbated by additional pressure on groundwater resources during periods of drought. DWR monitors and reports on land subsidence using various methods.
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Wells monitored by DWR and cooperating agencies are identified according to the State Well Numbering System, based on the public land grid. >>For More Information...

Other Useful Data & Monitoring Links

IWRIS   |   GAMA   |   USGS   |   Geotracker   |   Envirostor