FRESNO, Calif. >> Farmers in the Sacramento-San Joaquin River Delta who have California’s oldest water rights are proposing to voluntarily cut their use by 25 percent to avoid the possibility of even harsher restrictions by the state later this summer as the record drought continues.

Under the deal expected to be presented to state officials Wednesday, farmers would either take less river water for irrigation or leave a quarter of their crops unplanted. If the state accepts the deal, Delta water managers say it may become a model for farmers throughout California, who also are facing curtailments.

It is difficult to predict how many farmers will participate, said attorney Jennifer Spaletta, who represents several Delta growers, but those who do would be able to plan their crops earlier in the season with more certainty.

"From a business standpoint, it makes a lot of sense to do our part and to help in the emergency," Spaletta said. "At this point, obviously we’re in an absolute drought emergency."

Gov. Jerry Brown has ordered communities throughout the state to reduce water use by 25 percent. State water officials have encouraged water users to propose conservation measures, drawing the proposal from farmers.

Brown has been criticized for leaving farmers out of tightening regulations that force communities throughout the state to cut back on their water use. But this is the second consecutive year that junior water-rights holders have received orders to stop pumping river water to irrigate their crops.

Those making the proposal are so-called riparian water rights holders, who have the oldest and most secure access to California rivers. The harsh drought has caused state officials to say they may start ordering even these rights holders to stop taking water.

A coalition of Delta farmers and officials for the State Water Resources Control Board continue to work out the details and Spelatta said officials have responded positively to the proposal.

Delta farmers with the most senior water rights dispute the state can force them to stop irrigating their crops from California rivers, said John Herrick, manager of the South Delta Water Agency, who called this proposal a "safe harbor." He said that it would likely be adopted beyond the Delta by water users in the San Joaquin and Sacramento River watersheds.

Thomas Howard, executive director of the state water board, would ultimately rule on whether to approve the deal.

Michael George, who works for the state water board as the Delta Water Master, said that the proposal is a classic example of risk assessment by the farmers proposing the voluntary cutbacks.

"It is my personal opinion that a certain 25 percent reduction is a reasonable trade-off for regulatory uncertainty," George said. "Nobody benefits if uncertainty persists."