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1. Why did the County form the GSA?

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.

2. What authority does a GSA have?

SGMA gives GSAs numerous new tools and authorities to manage the groundwater and implement the objectives of the GSP. These include the authority to conduct investigations, determine the sustainable yield of a groundwater basin, measure and limit extraction, impose fees for groundwater management, and enforce the terms of a GSP. These authorities can be implemented by one or multiple GSAs. Chapter 5 of SGMA describes the powers and authorities in greater detail.

3. What does a GSA do?

The primary purpose of a GSA under SGMA is to develop and implement a Groundwater Sustainability Plan (GSP) to achieve long-term groundwater sustainability.  GSAs are empowered to utilize a number of new management tools to achieve the sustainability goal, such as: register and meter groundwater wells, mandate annual extraction and water level reports from individual wells, impose limits on extractions, mitigate against overdraft, implement rules and regulations, and assess fees to support creation and implementation of a GSP.

4. What is the legislative timeline for SGMA Implementation?

In medium and high priority basins, including the Napa Valley Subbasin, GSAs were required to develop and adopt a Groundwater Sustainability Plan (GSP) with coordination agreements, or other agreements, as needed, for sustainable management of the basin by January 31, 2022. GSAs in critically overdrafted basins were required to complete their GSPs by January 31, 2020. The GSAs have 20 years following the relevant deadline for GSP adoption to achieve the sustainability goal for their basin, including avoidance of undesirable results.

5. Does the GSA regulate surface water?

The regulation of surface water diversion and use is solely the authority of the California State Water Board. The county has no regulatory ability to affect this issue.

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