Cosumnes Subbasin | Groundwater Sustainability Plan (GSP)

The seven Groundwater Sustainability Agencies (GSAs) are working collaboratively to develop and implement a Groundwater Sustainability Plan (GSP) for the Cosumnes Subbasin.

A GSP must assess groundwater quantity, rates of input, extraction, and lay out a plan to show sustainability of groundwater resources over a 20-year horizon. If it is determined that groundwater supplies are being depleted over time, the GSP must contain a strategy to reverse this trend and ensure long-term sustainability of the water available to businesses, residences, farms, ranches, and ecosystems.

The GSAs have been meeting monthly since 2017 to consider input from community members, groundwater users, technical experts, hydrologist, geologists, and engineers to ensure the GSP meets local needs and complies with all State requirements outlined in SGMA. The GSP will be adopted and submitted to DWR by January 31, 2022. 

UPDATE: Final GSP Adopted and Submitted to State 

January 2022: As of January  12, all seven GSA Boards approved adoption of the Cosumnes Subbasin GSP and preparation for submission to CA DWR by January 31, 2022. On January 19, 2022, the Cosumnes Subbasin Working Group confirmed submitting the GSP to CA DWR.

DWR will notify those on its Sustainable Groundwater Management Program email list when the GSP has been posted to the CA DWR SGMA Portal and available for a 75-day public comment period.

[Subscribe to California DWR SGMP listserve for all SGMA updates]
[Subscribe to the Cosumnes Groundwater Authority listserve for Cosumnes Subbasin-specific updates]


Learn more about the GSP

Click the links below to learn more about the Cosumnes Subbasin GSP:

  • NEW! – File Directory: Final GSP documents. The directory contains eight (8) files:
    1. WORD – “Response to Public Comments_Redline”: Changes to the final draft Response to Public Comments approved by the Working Group. The final set of responses are included in Appendix F “Public Comments.”
    2. WORD – “Cosumnes Subbasin GSP_REVISED Public Draft_12_8_21_Redline”:  redline changes to the Public Draft to finalize the GSP. The changes to the Public Draft include additions provided by the GSAs and identified in the Response to Public Comments. 
    3. PDF – “Cosumnes GSP Final 12_13_21_complete”: complete GSP including text, figures, and appendices.
    4. PDF – “Cosumnes GSP Final 12_13_21_text only”: GSP text only.
    5. PDF – “Executive Summary Cosumnes GSP Final 12_13_21”: executive summary only.
    6. Appendices zipped – compressed directory containing each individual appendix to the GSP.
    7. Figures zipped – compressed directory containing each individual figure of the GSP.
    8. References zipped – compressed directory that contains references used to support GSP development that are not readily accessible through links provided in the GSP.