Recent: On October 11, 2019, Napa County provided a response to the Department of Water Resources’ (DWR) preliminary evaluation of the County’s alternative Groundwater Sustainability Plan (GSP) for the Napa Valley Subbasin. DWR’s initial recommendation is to not approve the County’s alternative GSP. Napa County prepared the response to address DWR's questions and other requested clarifications related to the alternative GSP.

Groundwater Stakeholder Survey

Napa County and the Watershed Information and Conservation Council (WICC) have developed an online survey to better understand the interests of groundwater stakeholders. The survey results will guide groundwater outreach efforts to advance Napa County's Groundwater Sustainability Program.

CLICK HERE to take the survey. Your input is very important and will help improve the various ways groundwater information and education programs are offered to our community.

The Importance of Groundwater

Groundwater is a vital source of water supply in Napa County. Residents, businesses and agriculturists rely on groundwater, as do fish, wildlife and natural habitats. It is essential to:

  • Preserve the quality and availability of all local and imported water supplies
  • Sustain groundwater supplies to meet future needs and availability during drought conditions
  • Anticipate and avoid potential environmental effects due to the overuse of groundwater
  • Anticipate and take steps to avoid potential losses in long-term groundwater availability and quality.

Everyone in Napa County has a stake in protecting the County's groundwater resources. Without sustainable groundwater resources, the character of the County would be significantly different in terms of its economy, communities, and ecology.

"Well Owners Guide, A guide for private well owners in Napa County (PDF) " is a new guide intended to make private well ownership a little easier, by alerting well owners of potential sources of contamination and the need for periodic water quality testing, by introducing the basics of proper well construction, destruction and maintenance, and informs well owners of their responsibilities in Napa County.

Annual Monitoring and Reporting

Napa County regularly monitors groundwater levels. Each year an annual report on groundwater conditions and trends is provided to the public. On March 19th, Napa County Public Works provided the Groundwater Sustainability: Annual Report - Water Year 2018 (PDF) to the Board of Supervisors. The 2018 Annual Report summarizes activities implemented to improve the understanding of groundwater resource conditions and actions taken to ensure continued groundwater sustainability in the Napa Valley Subbasin.

For more information about groundwater in your local area, visit the Watershed Information and Conservation Council (WICC) website. The WICC receives on-going groundwater updates at their bi-monthly meetings. Check the WICC event calendar for upcoming meetings.

Do-It-Yourself (DIY) Groundwater Level Monitoring

Napa County is offering assessments, training and tools to residents to help them monitor the level of groundwater in their well. This program allows residents to learn how water depth in their well changes over the course of the year and helps them to better understand how the groundwater reservoir beneath their land responds to winter recharge and use over the dry months. Measurements are best taken in the spring and fall over multiple years to see trends in recharge. You can learn more about the DIY Groundwater Monitoring Program by viewing this short video and downloading the program flier (PDF).

Alternative Groundwater Sustainability Plan (GSP)

Basin Analysis Report for the Napa Valley Groundwater Subbasin

Final documents of the Napa Valley Groundwater Sustainability - Basin Analysis Report for the Napa Valley Subbasin (Alternative GSP) are available below. The Final Alternative GSP was submitted to the Department of Water Resources (DWR) on December 16, 2016. Napa County is currently awaiting DWR's review. A hard-copy of the Alternative GSP is available at the Napa County Flood Control and Water Conservation District Office, 804 First St. Napa, (707) 259-8600.