Groundwater is water that is stored underground beneath our feet. We depend on it to drink, bathe, grow food, and more. Without proper care, our groundwater can run out or become contaminated. About 85% of Californians depend on groundwater for some portion of their water supply.

The Drinking Water Tool shows how communities in California may be vulnerable to groundwater challenges that could affect their access to long-term safe and affordable drinking water.

This tool tells you:

• Who makes decisions about your water supply and quality;

• Potential threats to groundwater quality;

• Potential impacts to groundwater supply from future droughts;

• How to get involved in local groundwater management decisions.

With severe drought conditions and climate extremes, we must protect our groundwater, especially in areas highly susceptible to water scarcity and contamination, such as the San Joaquin Valley and the Central Coast. Overpumping of our limited groundwater leads to dry wells, water contamination, land subsidence, and other harmful impacts. Communities who rely on shallow groundwater wells faced this devastating reality over the summer of 2022, with more than 1,400 wells running dry. From January to October 2023, over 430 households reported having a dry well and lost their only source of running water in California.

As Groundwater Sustainability Agencies develop and revise Groundwater Sustainability Plans under the Sustainable Groundwater Management Act, decision makers must address the needs of vulnerable communities. The Drinking Water Tool provides essential information to identify these communities and empower impacted residents to take a proactive role in managing their groundwater responsibly and equitably.

Use the tools below to learn more about groundwater issues in your area and throughout California.

Visit Getting Involved to learn how to use this information to take action in your community. To provide feedback, contact the Community Water Center.