COMMITTEE AGENDA MEMORANDUM
Agricultural Water Advisory Committee
Government Code § 84308 Applies: Yes ☐ No ☒
(If “YES” Complete Attachment A - Gov. Code § 84308)
SUBJECT: title
Receive an Update on the Periodic Evaluation of the Groundwater Basin Plans Pursuant to the Sustainable Groundwater Management Act.
End
RECOMMENDATION: Recommendation
Receive an update on the periodic evaluation of the Groundwater Basin Plans pursuant to the Sustainable Groundwater Management Act.
Body
SUMMARY:
Under California’s Sustainable Groundwater Management Act (SGMA), Valley Water serves as the Groundwater Sustainability Agency (GSA) for the Santa Clara and Llagas subbasins that are entirely within Santa Clara County. Valley Water has a Department of Water Resources (DWR) approved Alternative to a Groundwater Sustainability Plan (Alternative Plan) governing the management of these basins. Additionally, Valley Water serves as a GSA with San Benito County Water District (SBCWD) for the North San Benito Subbasin, a small portion of which is located in southern Santa Clara County. This basin is managed pursuant to a DWR-approved Groundwater Sustainability Plan (GSP).
Valley Water staff last updated the Agricultural Water Advisory Committee (Committee) on July 6, 2026 with an informational update regarding the dry water supply well analysis during the last drought and outreach plan for the required five-year periodic evaluation of the Alternative Plan that is due to DWR by December 17, 2026. This will be the second periodic evaluation and update of the Alternative Plan and is also referred to as the 2026 Groundwater Management Plan (GWMP). Since that Committee meeting, staff received notice from DWR that the 2025 Annual Water Year Report (Annual Report) met the requirements of SGMA. 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 Water Supply and Demand Management 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 updated Alternative Plan/2026 GWMP 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 Alternative Plan/2026 GWMP, followed by Board consideration of the plan for adoption. After plan adoption, Valley Water will submit the 2026 GWMP to DWR by December 17, 2026, as required by SGMA.
Wells - Historical Context
At the July 6, 2026 meeting, the Committee expressed interest in the number and type of wells over the past 10 to 20 years. Attachment 1 includes graphs of the number of wells and groundwater pumping (acre feet) by well type (municipal and industrial, agricultural, and domestic) in the Santa Clara Plain, Coyote Valley, and Llagas Subbasin from 2004 to 2024.
North San Benito Subbasin
Valley Water shares GSA responsibilities with SBCWD for the North San Benito Subbasin, which is primarily located in San Benito County. The periodic evaluation of the DWR approved GSP for this subbasin 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 it was decided to submit a 2026 periodic evaluation and GSP 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