August 15, 2017
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Plan for San Joaquin Valley Reservoir to Recharge Groundwater Draws Concern

The Semitropic Water Storage District proposes building a new reservoir on part of an ancient lakebed, then using it to capture flood flows to recharge groundwater. But others in the region fear it will deprive them of water.

By Matt Weiser

CALIFORNIA’S TULARE LAKE was once the largest body of freshwater west of the Mississippi River. Located at the southern tip of the San Joaquin Valley, it collected snowmelt from dozens of Sierra Nevada streams. Today, the giant lake is long gone: In the decades after the Gold Rush, it was drained and transformed into farmland.

Now, in a modern era of water scarcity, some are eager to see even a small bit of the old Tulare Lake restored. It could be an effective way to recharge groundwater that’s been overtapped by those same farms.

proposal from the Semitropic Water Storage District would seem to be the perfect answer. The district proposes to build a new reservoir on 12,000 acres, adjacent to Interstate 5 near Kettleman City, in Kern County. To be called Kettleman Reservoir, it would be formed on part of the old Tulare Lake bed by building levees up to 8 feet high. This new impoundment could store up to 30,000 acre-feet of water.

The water to fill the reservoir would come from “unallocated floodwaters” in the Kings River and other tributaries flowing out of Kings County to the north, which the district estimates to be available in one out of three years.

Some of the water would recharge groundwater directly as it seeps through the reservoir into the ground below. And some would be pumped into Semitropic’s existing groundwater storage bank, located some 25 miles south on the outskirts of Bakersfield, which serves farm irrigation customers in the region.

“Water captured and banked from the Kings River will be managed by the district to meet local water supply demands, mitigate groundwater declines, stabilize land subsidence, and improve sustainability of local groundwater resources,” the district wrote in a project description submitted to the California Water Commission in 2016.

But not everyone thinks the idea is so great. The Kings River, for starters, is considered “fully appropriated” by the State Water Resources Control Board. That means there is no additional water available. The only exception might be during flooding. But existing Kings River water users worry that by claiming “unallocated floodwaters,” Semitropic could deprive them of water they need to refill their own depleted aquifers.

This, in turn, could make it impossible for the Kings River region to comply with the Sustainable Groundwater Management Act (SGMA), said Craig Pederson, a farmer and chairman of the Kings County Board of Supervisors.

A regional map showing the location of the Kettleman Reservoir proposed by Semitropic Water Storage District. The reservoir would capture floodwaters from the Kings River to feed Semitropic’s large groundwater recharge bank to the south. (Image Courtesy Semitropic Water Storage District)

In a recent letter to Semitropic, the Kings County Board of Supervisors said the project “offends the efforts” of the county to manage its groundwater and poses “health, safety and welfare concerns.”

“We’ve got areas of our county that are severely overdrafted, some of the most overdrafted aquifers in the state,” Pederson said. “So anything that’s going to attempt to move surface water, which is going to be our lifeblood in meeting the demands of SGMA, is a concern to us.”

The 2014 groundwater act is the state’s first comprehensive attempt to regulate its aquifers. It requires all groundwater basins in the state to reverse and prevent chronic overdraft conditions. This will likely require major water conservation initiatives as well as harnessing any surplus water that can be found, like periodic flood flows once considered a nuisance.

Officials at Semitropic Water Storage District, including general manager Jason Gianquinto and board president Rick Wegis, did not respond to numerous requests for comment.

The district apparently plans to seek state bond funds to help pay for the project. In its submission to the California Water Commission, which will select projects for funding, Semitropic estimates its project will cost $500 million, including related pumps, pipelines and canals. It hopes to cover half of that cost using money from Proposition 1, the $7.5 billion water bond approved by the state’s voters in 2014.

But when that proposal was submitted in 2016, it seems Semitropic was considering a larger project: A reservoir with three separate impoundments and a total capacity up to 127,000 acre-feet. A more recent notice of preparation to prepare an environmental impact report describes the smaller project.

Proposition 1 money for water storage can only be used to fund the “public benefits” of water storage projects. And at least half of these benefits must be for improving ecosystem conditions. Other qualifying benefits include flood protection, recreation, emergency supplies and water quality.

Semitropic claims its project will benefit ecosystems by creating a mechanism to “exchange” banked floodwaters for water it buys under contract from the state Department of Water Resources. The contract water originates at Lake Oroville in Northern California and is delivered to Semitropic via the Sacramento-San Joaquin Delta and the California Aqueduct.

The proposed Kettleman Reservoir would be adjacent to the California Aqueduct, and Semitropic proposes to build a conduit that would allow water to be moved back and forth between them.

Semitropic describes a water exchange scenario in which DWR could reduce flood risk in the Delta by delivering excess water down the aqueduct to be stored in Kettleman Reservoir. Semitropic would then give up an equal amount of water under its normal contract deliveries, which DWRcould save in Lake Oroville to use as needed for fishery habitat.

Pederson is skeptical of these claims. All the while, he notes, Semitropic would also be exporting Kings River water that could be replenishing aquifers in Kings County.

“We as a board went down and visited Semitropic Water District and came away with a lot of questions with their operation,”Pederson said. “It just appears this is a project that’s trying to access public money to benefit someone other than the public.”

A row of massive pumps and pipes are part of Semitropic Water Storage District’s groundwater bank near Bakersfield. The district proposes to build a new reservoir in the historic Tulare Lake region to capture Kings River flood flows, which would then be piped to the groundwater bank. (Photo Courtesy

Another concern comes from the Kings River Conservation District, which has a number of responsibilities, including maintaining the river’s levees and channels for both flood control and water delivery. The river channel has limited capacity, and everyone who relies on the channel pays taxes to fund maintenance, said Paul Peschel, the district’s general manager.

Semitropic does not currently pay taxes to maintain the river, Peschel said. So if Semitropic begins tapping Kings River flood flows for its groundwater banking project, that raises a number of questions, Peschel says. How will Semitropic pay for its impact on the river channel and its levees? Will there be channel capacity left for people who do support the district and need to access their own water? If not, can the channel be enlarged? And who should pay for that?

“I wouldn’t say we’re opposed to it. Until we get more answers, it’s hard to say,” said Peschel.

He recently signed a joint letter with the Kings River Water Association that raises a number of questions about the project, including concerns about water availability for several irrigation districts that depend on the Kings River.

“I would say there’s concern in general, across the region, that there may not be sufficient water to support as many projects as there are being looked at,” Peschel said. “If you aren’t communicating and working together, you could be making it very expensive for everyone, potentially.”

Originally appeared at

Image Courtesy Semitropic Water Storage District

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