Delta farmers offer to take 25 percent less water

Dozens of California farmers whose century-old claims to rivers and streams have assured them a nearly endless water supply, at least up until now, are offering to give up a quarter of their water in exchange for a guarantee that the drought-plagued state won’t come clamoring for a whole lot more.

The unprecedented deal, submitted by a coalition of growers in the Sacramento-San Joaquin River Delta, is a response to four dry years that have left even those with the strongest rights to California water vulnerable to state-ordered cuts. While reductions are being forced on cities and towns, and lots of farmers have already taken blows, those with “senior water rights” have often gone untouched.

Rather than risk a hit in the future, senior water rights holders in the delta have laid out a proposal to relinquish 25 percent of their supplies, or plant 25 percent less, if state water officials agree not to demand the remaining 75 percent later, attorneys for the group confirmed Wednesday.

State officials have not yet acted on the offer. However, they’ve not only expressed support for the idea, but they’ve also suggested that they might expand upon it by giving property owners far beyond the delta a similar option of volunteering concessions.

Extending the deal to farmers in the Sacramento River and San Joaquin River basins could significantly ease pressure on California’s dwindling water supplies. As much as 80 percent of the state’s available surface water is consumed by agriculture, with some of the biggest farms, providing much of the nation’s fruit and vegetables, thriving in these watersheds.

“My instinct tells me that the savings will be substantial,” said attorney Jennifer Spaletta, who is working to cut a deal on behalf of delta growers. “Whatever efforts can be made to effectuate real water savings are really, really important to get us through the summer.”

The proposal has been months in the works.

As the State Water Resources Control Board has begun rationing water to farms in light of sparse mountain runoff, which normally makes up a third of California’s water supply, water cutbacks for even the most senior water rights holders have been entertained.

State law requires the water board to order curtailments on a seniority basis. While reductions are not uncommon, and many landowners with junior water rights have faced severe cuts in recent years, rarely have the most senior water rights holders, with claims dating back to the Gold Rush, been threatened.

Attorneys for delta farmers say some are willing to cut their losses now rather than risk a bigger loss in the future.

“We’d rather avoid something horrible,” said John Herrick, manager of the South Delta Water Agency, which advocates for the well-being of the delta and its landowners. “It’s easy to say we’re going to fight the battle for our rights, but that’s only easy to say until somebody sends you an order curtailing your water.”

Herrick also said growers prefer the certainty of knowing how much water they’ll get, even if it’s less than usual, so that they can more confidently make planting decisions.

The delta, which marks the confluence of the Sacramento and San Joaquin rivers, boasts more than 100 crops, with alfalfa, grapes, tomatoes and almonds among the staples.

“We’re also trying to help,” Herrick added, noting that some growers realize they haven’t been hit by the drought as hard as others and want to make a concession. “It’s nice to have delta farmers cast in a good light.”

The proposed deal would apply to delta landowners with “riparian rights,” meaning those who have senior claims to water because their property abuts a river or stream. Participation in the program would be voluntary.

Under the plan, property owners could choose to pump 25 percent less water from their adjacent tributary than they did in 2013, or fallow 25 percent of their land, in exchange for immunity from potential orders to stop pumping in the future, according to attorneys.

State water board officials said Wednesday they’re studying the details of the offer and expect to decide whether to move forward by the end of the week.

“Hopefully, something can be worked out,” said Dorene D’Adamo, a member of the agency’s governing board.

Jeanne Zolezzi, an attorney who represents growers in the San Joaquin River watershed, said she has also been in touch with state officials about offering cuts now to avoid orders to stop pumping later.

“We feel very strongly that a voluntary curtailment is much preferable,” she said.

Kurtis Alexander is a San Francisco Chronicle staff writer. E-mail: kalexander@sfchronicle.com Twitter: @kurtisalexander