COMMITTEE AGENDA MEMORANDUM
Water Supply and Demand Management Committee
Government Code § 84308 Applies: Yes ☐ No ☒
(If “YES” Complete Attachment A - Gov. Code § 84308)
SUBJECT: title
Receive an Update on Development of Five Year Update to Alternative Groundwater Sustainability Plan and Groundwater Sustainability Plan for All Groundwater Basins Managed by Valley Water Pursuant to the Sustainable Groundwater Management Act; Recommend Bringing Updated Alternative Plan to Board of Directors for Public Hearing and Adoption on November 10, 2026.
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RECOMMENDATION: Recommendation
A. Receive an update on the development of five-year update to Valley Water’s Alternative Groundwater Sustainability Plan; and
B. Recommend bringing updated Alternative Plan to the November 10, 2026, Board of Directors meeting for public hearing and adoption.
Body
SUMMARY:
Under California’s Sustainable Groundwater Management Act (SGMA), Valley Water serves as the exclusive Groundwater Sustainability Agency (GSA) for the Santa Clara and Llagas groundwater subbasins that are located entirely within Santa Clara County. In addition, Valley Water serves as the GSA for a very small portion of the North San Benito Subbasin that is located in the far southern portion of our County. The primary GSA for this subbasin is San Benito County Water District (SBCWD).
As the GSA for the Santa Clara and Llagas Subbasins, Valley Water has an approved Alternative to a Groundwater Sustainability Plan (Alternative Plan) that sets forth how these basins are managed. Every five years, Groundwater Sustainability Plans (GSPs), including Alternative Plans, must be re-evaluated and updated, and the next periodic evaluation to Valley Water’s Alternative Plan is due to the California Department of Water Resources (DWR) by December 17, 2026. In addition, the periodic evaluation to the North San Benito Subbasin GSP is due January 12, 2027.
Valley Water staff last updated the Water Supply and Demand Management Committee (Committee) on June 8, 2026 with an informational update regarding the dry water supply well analysis during the last drought and outreach plan for the required periodic evaluation of the Alternative Plan. This will be the second periodic evaluation of the Alternative Plan, which is referred to as Valley Water’s 2026 Groundwater Management Plan (GWMP). Since the June Committee meeting, staff received notice from DWR that the 2025 Annual Water Year Report (Annual Report) met the requirements of the SGMA and that no further information or action is required at this time. The Annual Report shows continued healthy and sustainable groundwater conditions in the Santa Clara and Llagas subbasins.
This Committee update summarizes progress on the periodic evaluation of the Alternative Plan for the Santa Clara and Llagas subbasins, including a summary of the July 30th public meeting, status of Valley Water response letters to public comments received during the public review period, and performance assessment of Valley Water’s outcome measures for groundwater sustainability. Staff will also share an update on the North San Benito Subbasin.
Santa Clara and Llagas Subbasins
Valley Water’s comprehensive groundwater management framework has maintained sustainable conditions in the Santa Clara and Llagas subbasins over many decades. The 2026 GWMP provides detailed information describing this framework, including the following major elements:
• Valley Water history, groundwater management authority, structure, and finances
• Basin setting and conditions including geology, groundwater levels and quality, groundwater dependent ecosystems, land subsidence, and seawater intrusion
• Water supplies, demands, and the groundwater budget
• Sustainable management criteria, including goals derived from Board Ends Policy E-2, effective strategies, and outcome measures to gauge performance
• Basin management programs and activities
• Groundwater monitoring and modeling
• Potential actions to address outcome measure performance and plan recommendations
While all sections are being updated to represent current basin conditions and Valley Water activities, the fundamental structure and content of the GWMP are largely unchanged as implementation of the plan has proven to be effective in maintaining sustainable groundwater conditions. Outcome measures are metrics to gauge performance in meeting sustainability goals. The groundwater quality outcome measure was revised slightly in the 2026 GWMP to report separately by subbasin and well type to more accurately represent groundwater conditions. Success in meeting the outcome measures for groundwater storage, subsidence, groundwater quality, and seawater intrusion are shown in Attachment 1.
Coordination and Outreach
Throughout the development of the 2026 GWMP, regular updates have been provided to the Committee, the Board’s Agricultural Water Advisory Committee, water retailers, and other interested parties. Valley Water hosted a well-attended public meeting on July 30, 2026, and the presentation, recording, and summary of the questions and answers are posted on Valley Water’s website here: <https://www.valleywater.org/SGMA>. On this website, the draft 2026 GWMP/Alternative Plan was available for public review from August 13 to September 25, 2026. Valley Water received comments from the public and will respond to each comment individually. Response letters are expected to be sent by late October and will be included in Appendix A of the final 2026 GWMP that is submitted to DWR.
Public Hearing and Plan Adoption
Valley Water is targeting the November 10, 2026, Board of Directors meeting for a public hearing on the updated 2026 GWMP/Alternative Plan, followed by Board consideration of the Plan for adoption. After adoption, Valley Water will submit the updated Plan to DWR by December 17, 2026, as required by the SGMA.
North San Benito Subbasin
As noted, Valley Water shares GSA responsibilities with SBCWD for the North San Benito Subbasin, which is primarily located in San Benito County. The periodic update to this GSP is being led by SBCWD, including all technical analyses. Valley Water staff are supporting the evaluation and update, including serving on the Technical Advisory Committee (TAC). The third TAC meeting was held at SBCWD on September 2, 2026, and the TAC decided to submit a GSP amendment with the periodic update.
At the October 26, 2026 Committee meeting, SBCWD and Valley Water staff will present the draft 2026 GSP periodic evaluation and amendment, which will be considered by both the SBCWD and Valley Water Board of Directors in December 2026.
ENVIRONMENTAL JUSTICE IMPACT:
There are no environmental justice impacts associated with this item.
ATTACHMENTS:
Attachment 1: PowerPoint
UNCLASSIFIED MANAGER:
Manager
Greg Williams, 408-630-2867