Napa County announced a new groundwater sustainability fee that will be assessed for agricultural, public water, and domestic users; growers should contact staff by July 10 if they qualify for adjusted rates or waivers. Draft incentive concepts for water conservation practices — including meter installation, cover cropping, and irrigation improvements — were presented but not yet adopted.
The Flood Control and Water Conservation District board approved a $93,870,379 FY 2026–27 budget, with major allocations toward active flood control construction and Measure A projects. Updated hydraulic modeling shows flood wall heights along the Imola-to-Hat reach may be slightly lower than in the 1998 GDM.
The public draft 2026 Water Availability Analysis, released for a 60-day comment period through May 26, 2026, proposes raising the Tier 1 groundwater use criterion on the Napa Valley floor from 0.3 to 0.5 acre-feet per acre for new and replacement wells. The Water Year 2025 Annual Report reported undesirable results for both groundwater storage and interconnected surface water. The draft WAA also introduces new Tier 3 protective standards for wells within 1,500 feet of significant streams.
Dry-farm vineyard soils stored water efficiently and supported deep roots; modeling found vineyard replant idling could reduce pumping ~1,250–2,500 acre-feet/year (2.5–10%) and improve streamflow, and a recharge heat map flagged priority areas near Calistoga, St. Helena, and north of Napa for managed aquifer recharge.
Committee supports groundwater extraction fees beginning in fiscal year 2026-27, with costs shared between the county (min $500,000 annually) and water users receiving notification in 2026. Research comparing ET measurements found OpenET models perform well in the region, while local CIMIS stations have experienced maintenance issues. 4 Managed Aquifer Recharge scenarios were explored, ranging from extended vineyard fallow periods to dedicated recharge basins, like Pajaro Valley's success.
