For the first time, growers in one of California’s most acutely water-stressed areas have to reveal how much groundwater they are pumping. For generations, they’ve been free to take water from wells on their own land without reporting to it the state.

The State Water Resources Control Board ordered landowners in parts of the San Joaquin Valley around Corcoran and Pixley to submit detailed reports by Friday.

The Tule and Tulare Lake groundwater subbasins were put on probation by the board in 2024 because they weren’t doing enough to control excessive pumping, which has caused levels to plummet. By collecting the data, the agency is preparing to charge landowners fees — $300 for each well plus a usage fee of $20 for each acre-foot of water.

“You can’t manage what you don’t measure,” said Natalie Stork, director of the state water board’s sustainable groundwater management office.

Stronger efforts to safeguard the water that remains will be based on these reports, she said.

Large farming operations have reshaped this part of the San Joaquin Valley over the last century. Tulare Lake was once the largest freshwater lake west of the Mississippi River, but it was drained to irrigate crops, and has reappeared only occasionally when floodwaters return.

On and around the dry lake bed, water gushes from wells into ditches to fields of tomatoes, cotton, almonds, grapes and other crops.

According to state estimates, the two regions combined lost about 213,000 acre-feet of groundwater in 2025 — roughly 45% of the annual water use of Los Angeles.

As the water table drops, the land is sinking. Since 2015, the ground in parts of the Tulare Lake area has subsided more than 6 feet, while part of the Tule area has dropped more than 7 feet.

The sinking has damaged part of the Friant-Kern Canal, a major water conduit for farms, reducing its carrying capacity and requiring $326 million in repairs.

State regulators have told managers of local water agencies they need to do more to address overpumping and slow land subsidence. They warn that hundreds of household wells could go dry.

More than 2,000 landowners had to report their groundwater use over the last year by the May 1 deadline. Small well owners are exempt, along with certain parts of the Tule area.

“Reporting the data, that’s something we just have to get used to,” said farmer Garrett Gilcrease, president of the Kings County Farm Bureau. He said submitting the data through the state’s online system was “cumbersome and tricky.”

The Kings County Farm Bureau sued to challenge the Tulare Lake area’s probation, and is seeking to block the state from charging fees, which are intended to cover costs related to the state’s oversight.

But Gilcrease said many farmers are concerned about paying so much at a time when their businesses are already hurting because of low crop prices and other factors.

“It’s approaching a depression,” Gilcrease said. “We’re in a time now where there is not a single crop that makes money.”

California was late to these measures among western states, but is now putting into effect its groundwater management law.

Under the 2104 law, local agencies must say how they’ll address overpumping by 2040. Gilcrease said growers want to see regulation phased in gradually.

“If we hit it the way they want now, it’s like smashing a fly with a hammer,” he said. “It’s going to kill the industry, and a lot of people are going to be hurt so bad that they have to close up shop.”

The area’s biggest landowners include farming giant J.G. Boswell Co. and grower John Vidovich, who runs the company Sandridge Partners. There are also small farmers growing pistachios, almonds and other crops.

In the Tule area, farmers have been reducing pumping under rules set by local agencies, leaving some fields dry and fallow.

“It’s a painful process to go through,” said Steve Jackson, a farmer who is working as a consultant helping other growers submit their water data. “A lot of farmers are being asked to make huge changes to their operations.”

In areas of the Central Valley where the state has found the groundwater is in “critical overdraft,” many local agencies are already tracking how much water comes out of wells, using meters on wells and estimates from satellite data.

Ahead of this week’s deadline, staff from the state water board held meetings with landowners to answer questions.

While the 2014 law put local agencies in charge of managing groundwater, it also called for the state water board to step in when they fell short.

So far, it has mostly offered leniency, ending probation in four areas, most recently the Delta-Mendota subbasin. State officials said enforcement measures were no longer needed after agencies improved their plans.

“They’ve made tremendous progress. It’s night and day,” said Erik Ekdahl, the board’s chief deputy director. “State intervention has been successful, and we believe it will continue to be successful.”