Groundwater

You can find more details about groundwater in your local area by visiting 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.

Recent: On March 20th, Napa County Public Works provided a Groundwater Sustainability: Annual Report – Water Year 2017 (PDF) to the Board of Supervisors, along with an accompanying report the Northeast Napa Management Area: An Amendment to the 2016 Basin Analysis Report for the Napa Valley Subbasin (PDF). The 2017 Annual Report summarizes activities implemented to improve the understanding of groundwater resource conditions and actions taken to ensure groundwater sustainability. The Northeast Napa Report provides additional detail about conditions in a proposed Northeast Napa Management Area, and establishes additional sustainable management criteria and actions to support continued groundwater sustainability in the Napa Valley Subbasin.

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.

Refer back to this webpage often to learn what Napa County is doing to comply with the SGMA and ensure the sustainability of local groundwater resources.

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 is a new program to allows residents to learn how water depth in their well changes over the course of the year and help 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).