California's Groundwater (Bulletin 118)

This link will redirect the user to California's Groundwater (CalGW) - Update 2020. CalGW Update 2020 is the latest update to California's Groundwater publicly released on November 16, 2021.

Two-page Fact Sheet on California's Groundwater and how to provide your input on the latest version of the report, California's Groundwater Update 2020.

Hoja informativa de dos páginas sobre las aguas subterráneas de California y cómo proporcionar su opinión sobre la última versión del informe, la Actualización de aguas subterráneas de California 2020.

Frequently asked questions, and corresponding answers, related to California’s Groundwater.

Preguntas frecuentes y respuestas correspondientes relacionadas con el agua subterránea de California

In conjunction with the release of California’s Groundwater Update 2020, DWR has compiled a comprehensive list of the official basin boundary descriptions for all of California’s 515 groundwater basins. These descriptions were originally developed by DWR as part of California’s Groundwater (B-118) Update 2003 and have since been updated for some groundwater basins as a result of the 2016 and 2018 Basin Boundary Modifications. To make locating descriptions easier, they have been organized by region which is determined by the first number of the basin number (i.e. 1-XXX).

Update 2016 updates portions of Bulletin 118 Update 2003 and includes time-sensitive information important to implementing the new Sustainable Groundwater Management Act (SGMA). Additionally, a new procedure for basin descriptions was developed as part of the basin boundary modification process. All basins with boundary modifications in 2016 have revised basin boundary descriptions that replace their 2003 descriptions.

Update 2003 is a comprehensive report on groundwater published in 2003. It describes California’s groundwater basins and subbasins, including basin boundaries, hydrologic and hydrogeologic summaries, groundwater storage capacity and water budget, groundwater level and quality trends, well yields, basin management, and references. It also includes basin reports for each of the 515 groundwater basins that existed in 2003. The basin reports can be found here.

This dataset includes the basin reports for the 515 groundwater basins developed as part of Bulletin 118 Update 2003. The reports include descriptions of basin boundaries, summaries of the hydrologic and hydrogeologic setting, groundwater storage capacity and water budget, groundwater level and quality trends, well yields, basin management, and references.

Image showing the Groundwater Sustainability Plan (GSP) Status, as of October 26, 2023. For questions or further information, contact sgmps@water.ca.gov.