Groundwater Sustainability in 2025
Californians love groundwater. When it’s clean and plentiful, it makes a cheap and reliable water supply for communities; it feeds rivers and streams, maintaining healthy flows and habitat; and it provides a critically important backup during a drought. It’s so popular that 60% of Californians rely on groundwater for all or part of their water supply.
We love groundwater so much that we’re in danger of using it all up. That’s why the Sustainable Groundwater Management Act (SGMA) is so important. We’re a decade into that law, which gives local groundwater managers in 107 groundwater basins around the state 2 decades (starting in 2020 or 2022) to sustainably manage their groundwater supplies.
How are they doing? No basin is perfect, but all but a few are taking the law seriously, and the state agencies responsible for oversight are doing their job.
Clean Water Action has been fully engaged in this process, working with allies around the state to ensure that voices of local communities, small farmers, and environmental representatives are included in these planning efforts. We’ve provided advice on community engagement; published a peer-reviewed article critiquing the groundwater sustainability plans; and issued a report on how small farmers are faring under the law. Working with our allies, we’ve convinced state agencies to require plans to fund replacement wells when over-pumping causes domestic wells to run dry.
This year Clean Water took on community engagement in the largest groundwater basin in the state. The Kern groundwater basin covers 1.8 million acres, and its plan was found inadequate in early 2023. That triggers a process at the State Water Board. In February of this year, the State Water Board held a hearing to decide whether the basin had done enough to get a passing grade; at our urging, the decision was postponed while the basin conducted community outreach. We worked with our community partners to support the process – commenting on the outreach plan, contacting community members, even assembling a focus group. The groundwater agency conducted an intensive campaign, appearing at local events and collecting feedback. Community members consistently expressed concerns about water quality, water availability and affordability. Those comments were included as an appendix to the plan, which the board approved in September. (Hint: we didn’t think it was good enough, but we don’t win every battle!)
Pesticides and Groundwater
This year Clean Water Action also turned its attention to the Department of Pesticide Regulation (DPR). For the first time since 1991, DPR is in the process of updating its groundwater protection list, which is a group of pesticides that have been determined to have the potential to pollute groundwater. Given the long and sad history of pesticides that have polluted groundwater, this seemed like a long overdue process. Our water program associate, Mac Glackin, participated in the update process and coordinated a sign-on letter signed by doctors, researchers, fellow advocates and environmental justice organizations providing guidance to DPR as they developed their update.
Nerd out on Groundwater!
More and more information on groundwater is now available in easily accessible formats. For example, the encyclopedia of California groundwater, also known as Bulletin 118, is in the process of being updated! You can find the draft here, along with past versions. We look not just at the basins managed under SGMA, but those basins that are considered too small for SGMA. We would also like to see volcanic aquifers, like those in the Trinity Alps that feed the headwaters of the Sacramento River, recognized and protected as the resource they are.
The Department of Water Resources (DWR) has also developed Cal Groundwater Live, a comprehensive database of information that has been collected on groundwater around the state. Groundwater levels, subsidence, dry wells, groundwater storage and recharge all are available for most of the state. Sometime in 2026, DWR is planning to add a search feature, so you can enter your address and pull up information about your local groundwater conditions. We're really excited to see this new feature.
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