TO: Technical Advisory Group for the Napa County Groundwater Sustainability Agency
FROM: Brian D. Bordona, Director of Planning, Building and Environmental Services
REPORT BY: Jamison Crosby, Natural Resources Conservation Manager
SUBJECT: Presentation on Public Draft 2026 Water Availability Analysis
RECOMMENDATION
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The TAG will receive a presentation by staff and technical consultants on the Napa County Public Draft 2026 Water Availability Analysis (WAA) Guidance document and supplemental Technical Report for Napa County’s updated draft well permitting standards.
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Procedure
Staff introduces.
Questions and answers with the TAG.
Public comments.
BACKGROUND AND DISCUSSION
In a presentation to the TAG on January 12, 2023, (then) Interim Director of Planning Building and Environmental Services (PBES), Brian Bordona, provided background information on the chronology of events which led to the development and evolution of Napa County’s Water Availability Analysis (first adopted in 1991 and revised in 2015) and set the stage for further revisions which have been incorporated into the 2026 Public Draft WAA Guidance document.
The Napa County Board of Supervisors (BOS) is committed to preserving groundwater for agriculture and rural residential uses within the County. The Public Draft 2026 WAA Guidance supports groundwater policies in the Napa County General Plan which will be updated starting in summer 2026 following the completion of an updated Baseline Data Report (BDR) which was released to the public in March 2026. Through proper management, water conservation, and ongoing stewardship of natural resources, the groundwater and interconnected surface water resources found within the County can be sustained for future generations.
The 2026 update reflects recent regulatory developments, including Governor Newsom’s Executive Orders (2022-2024) and formally integrates the Interim Well Permitting Requirements adopted by the Board in June 2023. It also addresses key groundwater and interconnected surface water management considerations that have emerged since the last major update in 2015, which followed adoption of the Sustainable Groundwater Management Act (SGMA) in 2014.
The updated WAA applies to project applications involving groundwater use through existing, improved, or new water supply systems, as well as proposals that would increase the intensity of groundwater extraction on a parcel. It will most commonly be required for discretionary projects that rely on groundwater, such as wineries, vineyard development, commercial uses, and certain residential projects.
By formally integrating these updates, the 2026 WAA establishes a cohesive framework that aligns local project review with state groundwater sustainability requirements, with the goal of achieving subbasin sustainability by 2042. The release of these draft documents represents an important step in protecting Napa County’s groundwater resources and watersheds, while providing clear and objective standards for applicants and decision-makers.
The Public Draft 2026 WAA Guidance document was posted on the PBES homepage for public comment on March 27, 2026. Comments may be submitted through May 26th to groundwater@countyofnapa.org. The draft is available at <https://www.napacounty.gov/589/Planning-Building-Environmental-Services>.
ENVIRONMENTAL IMPACT
ENVIRONMENTAL DETERMINATION: The proposed action is not a project as defined by 14 California Code of Regulations 15378 (State CEQA Guidelines) and therefore CEQA is not applicable.
SUPPORTING DOCUMENTS
A. Presentation: Patrick Ryan, Napa County Assistant Planning Director PBES, Napa County Public Draft 2026 Water Availability Analysis Guidance Document and Technical Report.