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Blog Post · June 10, 2024

Commentary: The San Joaquin Valley Pumps Too Much Water. But There Are Signs of Progress

photo - Irrigation Pump on a Farm Near Spreckels, California

This commentary was published in the Sacramento Bee on June 6, 2024.

When it comes to reducing the overuse of groundwater in the San Joaquin Valley, the recent news has not been great. In March of last year, state officials deemed that groundwater sustainability plans for six of the valley’s 15 groundwater basins were inadequate. At an April hearing, one basin was put on probation by regulators to reduce overpumping.

The mood in other basins is understandably anxious as their futures remain unclear. Meanwhile, local agencies are suing groundwater pumpers in one basin for causing a major canal to sink.

But is the situation beginning to turn around? Despite some discouraging headlines, we think so.

In 2014, California finally joined other western states and started regulating its groundwater with the adoption of the Sustainable Groundwater Management Act (SGMA). It’s been a difficult journey, but it’s helpful to recognize the progress that’s been made.

Ten years ago, the valley had no groundwater sustainability agencies or plans to end overdraft. Now, it has both. Many basins are taking steps to avoid the worst impacts of overpumping, and some have begun measures to reduce groundwater use.

And as we show in some new research, many are ramping up efforts to boost groundwater supplies by capturing and storing unused surface water underground. Groundwater recharge has long been practiced in parts of the valley, and in a recent survey of what happened in 2023—a very wet year—we found that its adoption is spreading. Comparing our results to a similar survey we conducted in 2017 (also very wet), we found some encouraging new signs.

Recharge efforts are expanding. More San Joaquin Valley water agencies are recharging water, even in areas that lack access to ample surface water. And volumes are up: around 7.5 million acre-feet—or over 30% of the valley’s average annual water use—were socked away in aquifers in 2023, a whopping 17% increase from 2017.

Recharge methods are evolving. Agencies have been building more dedicated basins to capture water for recharge, and this paid off in 2023. They also reported growing enthusiasm among farmers for spreading water on their fields, a once-controversial practice considered an excessive use of water. While recharge on farmland remained a small portion of the total volume recharged, its cost-effectiveness—and ability to help reduce downstream flood risk—makes it an exciting area for expansion.

Local and state policies have helped. Many local agencies are now tracking how much groundwater is used and how much is replenished. Some have begun offering groundwater credits to landowners who perform recharge on their lands. This means that landowners will be able to directly benefit from the water they recharge by using a portion of it later. State agencies helped by funding recharge projects and facilitating the diversion of floodwaters during the peak of the 2023 recharge frenzy.

Make no mistake, these changes did not happen overnight. Agencies that managed to stash water underground in 2023 told us that such a successful recharge season wouldn’t have been possible without years of planning and preparation.

Of course, groundwater recharge is only one piece of the SGMA puzzle. Basins must also continue working on ways to reduce demand for groundwater and avoid harmful impacts of pumping, such as drying wells and sinking lands.

And there’s more to be done on recharge. With additional preparation, we estimate that much more water could have been stored in 2023. Many of the barriers we flagged in 2017 still exist. More infrastructure is needed to convey water to suitable recharge sites. And the state should further clarify rules for when and how much water can be diverted safely.

But the clear signs of progress bode well for the valley’s future. This should encourage all parties to keep building on this momentum.


Drought groundwater groundwater sustainability San Joaquin Valley SGMA Water Supply Water, Land & Air