DWR Releases Final California’s Groundwater: Bulletin 118 – Update 2025, Celebrates Groundwater Awareness Week ~ MAVEN'S NOTEBOOK

As Groundwater Awareness Week winds down, the Department of Water Resources (DWR) today released the final California’s Groundwater: Bulletin 118 – Update 2025 (CalGW Update 2025). CalGW Update 2025 provides a comprehensive inventory and assessment of available information on the occurrence and nature of groundwater and informs decisions on the protection, use, monitoring and management of the resource. This five-year update builds on the CalGW Update 2020 by integrating data submitted to DWR by local agencies under the Sustainable Groundwater Management Act (SGMA), including information reported in groundwater sustainability plans (GSP), alternatives to GSPs, annual reports, and other groundwater initiatives. CalGW Update 2025 is part of a comprehensive suite of resources designed to support groundwater understanding and management across the state, including the Semi-Annual Updates, CalGW Live, and the Basin Characterization program.

The final CalGW Update 2025 contains a Highlights document (available in English and Spanish) and a detailed Statewide Report (Chapters 1 – 6), which features current knowledge of groundwater resources including information on the location, characteristics, use, management status, and conditions of the state’s groundwater. Also included is an info-graphic summary of the ten hydrologic regions, showing regional groundwater at a glance (Chapter 7), and all final appendices, such as findings and recommendations that support the future management and protection of groundwater, a glossary of terms, reference materials, data methods and assumptions, and an update on land subsidence in California. This information can help communities and local water managers work together to find unique ways to manage their groundwater basins for long-term reliability and support actions being implemented as part of Governor Gavin Newsom’s 2020 California Water Resilience Portfolio.

The final release of CalGW Update 2025 consists of files and supporting data listed below. A fact sheet on the CalGW Update 2025 is available in English and Spanish. A three-page overview describing the structure and key content of CalGW Update 2025 and a Key Topics Index for the report is also available. The set of data and resources for California’s Groundwater Update 2025 (Bulletin 118) can be found at the following website: https://data.cnra.ca.gov/dataset/calgw_update2025.

California’s Groundwater: Bulletin 118 – Update 2025

Highlights: English, Spanish
Statewide Report: Chapters 1-6 (Large file: 50 MB)
Statewide Report: Chapter 7 Regional Summaries (Large file: 50 MB)
Appendix A: Findings and Recommendations
Appendix B: Glossary
Appendix C: Methods and Assumptions
Appendix D: Citations and Links
Appendix E: Hydrologic Region Basin Maps with Basin Tables
Appendix F: Water Use Data
Appendix G: Hydrologic Region, Basin, and County Data
Appendix H: California’s Groundwater: Semi-Annual Updates
Appendix I: Update on Land Subsidence in California
Appendix J: Projects and Management Actions

This final publication is released after DWR has incorporated public comments, which were accepted during a 45-day comment period after the draft release on October 20, 2025. DWR also held a public webinar, which included an overview of the draft document and served as a venue to ask questions and provide public comments. Materials from the draft CalGW Update 2025 can be found here:

11/4/25 Public Webinar presentation recording on draft CalGW Update 2025– English & Spanish captions.
11/4/25 Public Webinar presentation slides– PDF file.

CalGW Comprehensive Suite of Resources

DWR will soon release the Spring 2026 version of California’s Groundwater: Semi-Annual Updates, which will expand upon groundwater data released last fall and also include annual report information submitted by groundwater sustainability agencies. The report will provide a timely overview of statewide groundwater levels, land subsidence, well infrastructure, and the status of California’s groundwater monitoring conditions, helping water managers track short-term trends and make informed decisions that support sustainable groundwater management. These updates will continue to serve as a key resource for groundwater managers during SGMA implementation.

DWR’s California’s Groundwater Live (CalGW Live) website was first released in conjunction with the Bulletin 118 – Update 2020 and includes user friendly and interactive content meant to inform the public with the latest groundwater and groundwater-related information. Along with the release of the draft CalGW Update 2025 and the Fall 2025 Semi-Annual Update, DWR also expanded the content available on the CalGW Live website. New interactive dashboards are included for GSP evaluation status, GSP Monitoring Network specific to groundwater levels, and annual report data submitted by groundwater sustainability agencies. The new annual report dashboards include interactivity and statistics for groundwater recharge, change in groundwater storage, and groundwater extractions.

For more information about this update and additional groundwater information, see the following resources: