Basin Characterization Program

Image showing an overview of the basin characterization process with a helicopter and satellite collecting data over a groundwater basin.

Schematic showing groundwater aquifer properties and data collection methods available under the Basin Characterization Program.

DWR has a long history of studying and characterizing California’s groundwater aquifers as a part of California’s Groundwater (Bulletin 118). Groundwater aquifers, where water is stored underground, provide approximately 40 percent of the State’s total water supply during an average year and up to 60 percent in dry years. California’s groundwater aquifers are categorized into a total of 515 groundwater basins and subbasins. The Basin Characterization Program provides the latest data and information about California’s groundwater basins to help local communities better understand their aquifer systems and support local and statewide groundwater management.  

DWR’s historic Basin Characterization efforts include providing technical assistance through the collection, analysis, and sharing of various datasets through the following projects and initiatives:    

  1. California’s Groundwater – Bulletin 118 
  2. California Statewide Groundwater Elevation Monitoring (CASGEM)  
  3. InSAR Satellite-Based Subsidence Data
  4. Online System for Well Completion Reports (OSWCR) 
  5. Statewide Airborne Electromagnetic (AEM) Surveys 
  6. Technical Support Services  

DWR is now moving into the next phase of Basin Characterization where new and existing data will be integrated to create three-dimensional models that identify aquifer structures and conditions more clearly than ever before. We are expanding data collection efforts and developing new data visualization tools to make the data more accessible to a broad audience. All Basin Characterization Program activities will be documented in California's Groundwater, Bulletin 118.  

The Basin Characterization Program will provide valuable data and resources for understanding and managing California's groundwater on a local, regional, and statewide level.