Some California growers have found ways to to recharge precious groundwater

ARVIN, Calif. — In the southern San Joaquin Valley, where roads cut through thousands of acres of orange groves, grapevines and carrot fields, a canal reaches a linchpin that keeps the farming economy going: dozens of oblong ponds filled with shimmering water.

While many parts of California’s Central Valley are struggling to counter widespread overpumping and declining underground water levels, the irrigation agency here is using the ponds to effectively swallow gulps of river water, getting it to seep into the soil and recharge the groundwater.

“That sandy ground, when you put the water on it, it percolates into the groundwater and it recharges,” said Jeevan Muhar, chief executive officer of Arvin-Edison Water Storage District. “So it’s underneath us. We can see that water come up.”

The irrigation district tracks groundwater levels. In dry times, when it needs to tap into stored water, it uses dozens of wells to pump it out and send it flowing to farms.

The Tejon Spreading Works is part of a network the Arvin-Edison Water Storage District uses to recharge groundwater.

A new scientific study cites Arvin-Edison as one of dozens of areas where local efforts have managed to halt declines in water levels and allow aquifers to come back up.

“Unfortunately, groundwater is being depleted rapidly in many areas. However, groundwater depletion can be solved,” said Scott Jasechko, a UC Santa Barbara professor of water resources who authored the study in the journal Science.

Jaseshko examined 67 cases of groundwater recovery around the world, where water levels rose after prolonged decline. It happened three main ways: policy changes, tapping alternative water sources and replenishing aquifers.

In most cases, getting river water was key. In California, groundwater has rebounded in areas that obtained more water from canals or pipelines decades ago, including Santa Clara Valley, Livermore-Amador Valley, South Yuba Basin, Yucca Valley and parts of Los Angeles.

Arvin-Edison Water Storage District’s South Canal flows through farmland in Kern County.

Arvin-Edison Water Storage District, near Bakersfield, started building levees and digging basins for imported water in the 1960s. As the water sank into the soil, it helped raise groundwater levels in the following decades.

If it weren’t for these efforts over the years, Muhar said, levels would have dropped several hundred feet.

Still, he said the last 15 years have been particularly challenging. The agency has received less imported water during severe droughts, and average groundwater levels have gone down again.

He said some areas in Arvin-Edison’s 132,000-acre territory require more work to stabilize the aquifer because it is declining.

A spillway regulates the water level in Arvin-Edison Water Storage District’s South Canal, sending water into a pond in Kern County.

Muhar walked beside a pond at the Tejon Spreading Works, where ducks bobbed in the shallow water.

“You want to take advantage of the wet years, grab that water before it’s lost to the ocean or other locations, and bring it into these types of areas,” he said.

In 2023, which was extremely wet, the agency took in that abundant water and banked it underground. This year, by contrast, Muhar said Arvin-Edison will pump out more than it deposits underground.

“It’s managing the extremes of California water,” he said.

When that saved water is pumped from wells, it flows via canals and pipes to the fields of about 120 growers, irrigating onions, peaches, almonds, pistachios, potatoes, tomatoes and other crops.

Other agencies are recharging aquifers at dozens of sites across California and are building more facilities to replenish groundwater.

Some projects in the San Joaquin Valley are successful and well-known enough that water managers and researchers have visited from other parts of the world, including China and Ukraine, to see how agencies are doing it, Muhar said.

“It is the water banking capital of the world,” he said, “and we’ve been doing it for a long time.”

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Arvin-Edison is doing a good job managing groundwater together with river water, said Bridget Scanlon, a research professor at the University of Texas at Austin’s Jackson School of Geosciences, who was not involved in the latest study.

It takes a sophisticated approach, she said, while keeping the system going through wet periods and droughts.

The study also examined different cases in where it was a policy change that helped groundwater levels rise.

In Tokyo, regulations imposed limits on pumping. In Lima, Peru, well-drilling was banned in some areas. And in Bangkok, higher pumping fees helped water levels rebound.

In farming areas of Saudi Arabia, groundwater levels have risen since the country began phasing out water-intensive alfalfa and other hay crops.

Fast-growing urban areas in the western United States have found ways to raise groundwater levels by tapping river water and channeling it underground.

Las Vegas injects Colorado River water directly into the aquifer using special wells, and has done so since the late 1980s.

In Arizona, parts of the Phoenix and Tucson areas have boosted groundwater by routing Colorado River water to basins carved into the desert, where it sinks underground.

The Colorado River, however, is overtapped and increasingly vulnerable to cutbacks as global warming drives longer and more intense drought.

In a 2025 study, Scanlon and other researchers wrote that cuts in Colorado River water will “decrease critical replenishment of the aquifers” in central Arizona in the coming years, and could lead to further groundwater declines.

In California, the 2014 Sustainable Groundwater Management Act set requirements for local agencies to curb overpumping and stabilize aquifer levels by 2040.

The Tejon Spreading Works was built in the 1960s along the alluvial fan of Tejon Creek to take in water from a canal and store it underground in the aquifer.

The farmers in Arvin-Edison are better positioned than those in other areas that depend entirely on groundwater. Researchers have calculated that large portions of California’s irrigated cropland will need to be permanently left dry in the coming years.

To reduce water use and comply with the groundwater law, Arvin-Edison is starting to buy some farmland and leave the fields fallow.

Muhar said the agency recently transformed 350 acres into more ponds to replenish groundwater, and it plans to buy and retire more farmland.