Report targets waste, inefficiency in agricultural water use

California should more aggressively enforce the state’s ban on wasteful water use and crack down on inefficient irrigation practices, a state watermaster recommends.

In a report that will be presented next week to the State Water Resources Control Board, Delta Watermaster Craig Wilson wades into a potentially explosive area of water law: the “reasonable use” doctrine in the state Constitution.

The principle, reinforced in statute and court decisions, holds that a water right does not include the right to waste water and mandates that “the water resources of the state be put to beneficial use.”

Although it’s a cornerstone of California law, the clause has been enforced mostly on a case-by-case basis, usually when one person claims another’s water use is unreasonable.

“The doctrine could and perhaps should be applied more broadly,” said Wilson, an attorney who devoted his report to agriculture — the sector that uses most of the state’s developed water supply.

“Agriculture is using so much water. … You don’t need a lot, at least on a percentage basis, of better efficiency to start adding up to serious water” savings, he said.

His report recommends that the state board convene a summit, create an enforcement unit and streamline what Wilson characterized as “cumbersome” enforcement procedures.

“I think it’s long past time that the state focus on what is really a reasonable and beneficial use of our water,” said Pacific Institute President Peter Gleick, who has argued that California agriculture could cut its water use by 10% to 15% if it adopted more sophisticated irrigation techniques. “There’s been no effort to identify and challenge unreasonable uses of water.”

“It’s a hard issue to raise,” Gleick added. “Because one person’s reasonable use is another person’s unreasonable use.”

Mike Wade, executive director of the California Farm Water Coalition, disputed Wilson’s conclusion that “small changes” in irrigation methods can yield “significant amounts” of water savings. He also said some of the report’s suggestions would be prohibitively expensive to implement.

For instance, Wade said, it would cost hundreds of millions of dollars for irrigation districts to build systems that could deliver supplies to farmers on demand, as opposed to commonly employed rotation schedules that may send water to fields regardless of whether it’s needed.

Wade also took issue with Wilson’s suggestion that irrigators evaluate more efficient practices as part of their water diversion permits. Such a requirement would rob farmers of flexibility in deciding which crops to grow and how to grow them, he said.

bettina.boxall@latimes.com