Where'd the water go? Underground storage

Jul. 8—This hasn't just been a historic year for Kern County water delivery. The year 2023 has also been extraordinary for recharging aquifers that store local supplies for dry years ahead.

Water managers say years of investment in expanding local recharge capacity is paying off — and so are recent public-private partnerships that have turned former orchards and ag fields into large, temporary basins that allow surface water to infiltrate underground pools.

The rising surplus has helped the area recover from years of worsening drought, but it does little to ease concerns about impacts from upcoming groundwater pumping restrictions, and local authorities caution against easing up on conservation.

Still, predictions that this will be a record year for California underground water storage improve the county's position for prospering into the future.

"We're doing it," said Dan Bartel, engineer-manager at the Rosedale-Rio Bravo Water Storage District, which this year expects to put away five years' worth of water for 8,000 residential customers and farmers representing 28,000 acres of farmland.

That total represents a full year's supply, more than the district could have stored as recently as 2017, Bartel estimated, owing to millions of dollars in public and private investment to expand the district's recharge capacity.

General Manager Jon Parker at the Kern Water Bank Authority reports its recharge basins are "essentially full" as they continue to take in an average of about 4 inches per day across 32 square miles of surface ponds.

He said the district is on track to store some 600,000 acre-feet of water this year, or 6% more than the last big wet year in 2017, when the bank put away about as much water as all of Isabella Lake can hold at full capacity.

"Wet years like this are great," he said. "I'm sure it'll rank as one of the top recharge years."

More is at play than the record snowpack that loomed above Isabella Lake in the spring and has flowed down the Kern River in a torrent ever since. The State Water Project is delivering local customers 100% of their contracted amounts for the first time since 2006, and federal water contracts are also moving large volumes to Kern.

The city of Bakersfield's 2,800 acres of recharge capacity held up well after repairs were made prior to heavy flows in the spring, Assistant Water Resources Director Daniel Maldonado said by email. Some 145,000 acre-feet has been stored so far this year — more than twice the average, he reported, with another 50,000 acre-feet expected through fall.

But keep in mind: This came after three years of a historic drought that required heavy groundwater pumping with minimal recharge, he noted.

Such pumping won't end with this year's bounty, Maldonado emphasized, and rates paid by the city's customers aren't expected to come down just because of the wet winter. He added the city is always looking for ways to expand its recharge capacity.

"We will assess our facilities at the end of the year and look for areas to improve," Maldonado wrote.

General Manager Jason Gianquinto at Semitropic Water Storage District explained that not all local farmers receiving water this year are using it for irrigation. Some are instead doing what he called "opportunistic recharge," building temporary berms on fallowed property to bank water — and earning groundwater credit for their trouble.

Sometimes such work is done at the landowner's expense and sometimes it's paid for by a water district, or some combination thereof.

Meanwhile, the price of surface water for irrigation has sunk from a high of about $1,000 per acre-foot last year to lately about $100, which Gianquinto said roughly equals the district's delivery cost.

None of this, he said, does much to change farmers' outlook under the Sustainable Groundwater Management Act, which is still expected to fallow a lot of local farmland in the years ahead.

"This is a great year," Gianquinto said, "but it's not time to take our foot off the gas pedal as far as SGMA implementation."

Executive Director Jenny Holtermann of the Water Association of Kern County said by email 2023 has presented a tremendous opportunity for water storage. "We haven't seen this much water flow down the Kern River and into our valley in 40 years," she wrote.

But she cautioned that no one knows how long it will be before the county gets another wet year like this.

"It is always important to conserve our water and be the best stewards with this precious resource," she wrote. "Now is the time to ensure we are leading the effort in water conservation, banking, and storage efforts."