The preparation of a Groundwater Sustainability Plan (GSP) is required under the 2014 Sustainable Groundwater Management Act (SGMA). SGMA is comprised from a three-bill legislative package, including AB 1739 (Dickinson), SB 1168 (Pavley), and SB 1319 (Pavley), and subsequent statewide regulations issued by the Department of Water Resources (DWR).
GSPs must be prepared for all State-designated medium and high priority groundwater basins and subbasins. The Napa Valley Subbasin was designated as a medium priority by DWR in 2014. In 2019, the Napa Valley was re-designated as a high priority groundwater subbasin. The change in priority designation for the Napa Valley was not due to groundwater conditions. The high priority designation was based on changes in estimates for the Napa Valley regarding future population, the total number of wells, and water quality. On February 6, 2020, the Napa County GSA submitted notification to the Department of Water Resources of their intent to prepare a Groundwater Sustainability Plan for the Napa Valley Subbasin.
If the County did not form a GSA, then groundwater management would have been directly administered by the State Water Board. The GSA was formed to ensure that Napa Valley’s natural resources would remain under local control for the benefit of our residents and other beneficial users.