Please see the RECENT POSTS (in the column on the right) for the latest CGA information!
JOIN US FOR A WEBINAR ON THE NEW PILOT DOMESTIC WELL MITIGATION PROGRAM:
NEW! PILOT DOMESTIC WELL MITIGATION PROGRAM: Colusa Groundwater Authority, in cooperation with the Glenn Groundwater Authority and the Corning Sub-basin Groundwater Sustainability Agency, have implemented a new pilot Domestic Well Mitigation Program to protect and support residents whose drinking water wells have been impacted by declining groundwater levels or land subsidence. CLICK HERE for more information, including program details and application forms.
ENGINEER’S REPORT FOR SGMA OPERATIONAL ASSESSMENT 2025-26: The CGA Board approved the Engineer’s Report for the proposed operational assessment to support GSP implementation on June 10, 2025. To review the Engineer’s Report, please click HERE.
To view the Colusa Fee Project PARCEL MAP OF USER CLASS ASSIGNMENTS, click on this link: https://arcg.is/0eyTPO.
COLUSA SUBBASIN ANNUAL REPORT FOR WATER YEAR 2024 has been submitted to DWR and is available HERE.
ANNUAL REPORT WEBINAR: If you missed our webinar on May 20, 2025, you can view the presentation slides HERE.
AVAILABLE NOW: Colusa Subbasin Groundwater Conditions in Water Year 2024– a summary of the information in our Annual Report.
REVISED GROUNDWATER SUSTAINABILITY PLAN RECEIVES DWR APPROVAL
In February 2025, the state Department of Water Resources approved the Revised Groundwater Sustainability Plan for the Colusa Subbasin. The Revised GSP includes enhanced programs to address subsidence, initiate a demand management program, and mitigate domestic wells impacted by declining water levels below GSP targets.
Click HERE to review the Revised GSP for the Colusa Subbasin.
To view data on groundwater conditions in the Colusa Subbasin, go to DWR’s data viewer: https://sgma.water.ca.gov/sgmadataviewer#landsub.
Drought Resources
Please visit the following County of Colusa webpage for local drought information and assistance programs: Water Resources | Colusa County, CA – Official Website (countyofcolusa.org)
PUBLIC WORKSHOPS ON SUSTAINABLE GROUNDWATER REGULATION AND DRAFT CHAPTERS 1 THROUGH 4 OF THE COLUSA SUBBASIN GROUNDWATER SUSTAINABILITY PLAN
December 9, 2020 at 5:30 p.m. and December 10, 2020 at 1:00 p.m.
If you missed these public workshops, recordings are available on the Colusa Subbasin SGMA facebook page.
Click the links below for more information about these important meetings:
- SGMA Series Press Release
- SGMA Series Flyer (English)
- SGMA Series Flyer (Spanish)
- Meeting Agenda
- Meeting Presentation
- December 9, 2020 Workshop Summary and Presentation
- December 10, 2020 Workshop Summary and Presentation
Welcome to the Colusa Groundwater Authority (CGA) website.
The Colusa Groundwater Authority is the Groundwater Sustainability Agency (GSA) for the Colusa County portions of the groundwater basins that are subject to the Sustainable Groundwater Management Act (SGMA).
Two groundwater sub-basins in Colusa County are subject to SGMA:
- Colusa subbasin (5-021.52) which spans portions of Colusa and Glenn Counties
- Butte subbasin (5-21.70) which spans portions of Colusa, Glenn and Butte Counties
For an interactive map and more information about groundwater basins, visit the DWR Groundwater Basin Boundary Assessment Tool (BBAT)
We hope you will explore this website to learn more about SGMA and the Colusa Groundwater Authority, and check back often for updates.
Website Structure
- About Page: Find information about the CGA Board
- SGMA Page: Find information about the Sustainable Groundwater Management Act
- Meetings Page: Find information about the CGA’s meeting schedule
- Agendas and Minutes Page: View/download past and current meeting agendas and approved meeting minutes
- Presentations Page: View/download guest presentations from past CGA meetings and public outreach meetings
- Projects Page: Learn about local groundwater projects and studies
- Groundwater Sustainability Plan: Find information about Groundwater Sustainability Plan development in the Colusa and West Butte Subbasins, and other surrounding basins
- Basin Boundary Modification: Find information about the CGA’s 2018 Basin Boundary Modification in portions of the Colusa and West Butte/Butte Subbasins
- RFPs: Find any current Requests for Proposals from the CGA
- Public Outreach Page: View/download CGA Newsletters and other outreach publications and discover opportunities to engage in public outreach activities
- Butte Subbasin Page: Learn about SGMA implementation efforts in the Butte Subbasin.
- Contact Us Page: Sign up to receive news and updates, and/or leave questions or comments for the CGA
- Events Calendar: Check the calendar for upcoming meetings, workshops and other local water-related events