In the latest salvo in a raging legal war over the Delta environment and its water, environmentalists on Friday sued to force state regulators to use the same ancient legal powers they used to prevent Los Angeles from drying up Mono Lake in the 1980s.
The lawsuit sidesteps the legal and scientific battles over the region's endangered species and instead demands regulators apply their powers to consider "public trust" values under a doctrine that has roots in the laws of ancient Rome.
Those values can include a wide variety of things, including the future viability of commercial salmon runs, aesthetic beauty and recreational attributes of the coast's biggest estuary.
While a number of planning processes are moving forward that promise to better protect the Delta, the shocking collapse of the backbone of California's king salmon runs in recent years was one of the reasons the lawsuit was filed, said a lawyer for the coalition.
"I don't think we can wait for all of these processes," said lawyer Michael Jackson. "They could be too late, we think."
Citing a July report by state regulators and earlier reports that later were shelved, Jackson said if environmentalists win the case Delta water users might have to cut by half the amount of water they got during most of the 2000s.
He said better conservation, desalination and water recycling would offset those cuts.
"The economy will not suffer from reduced pumping out of the Delta," Jackson said. "We believe all of the evidence for a solution to the problem in the Bay-Delta already exists. We will try to get that evidence in front of a judge."
A spokesman for the Department of Water Resources, which pumps Delta water to the Bay Area, Kern County and Southern California, declined to comment, saying the department's lawyers had not reviewed the lawsuit.
But William Rukeyser, a spokesman for the State Water Resources Control Board, which regulates the state's water project and administers water rights, said that while he could not comment on the lawsuit, his agency is moving forward with plans to better protect the Delta.
"We are in the middle of a variety of things to protect the Delta," he said.
In July, the board adopted an advisory report suggesting that water users in the Delta watershed would have to use far less water to support a healthy estuary.
The report addressed not only users of water pumped out of the Delta -- including Southern California and San Joaquin Valley farm districts, as well as the Tri-Valley and South Bay -- but also agencies that rely on upstream dams, a category that includes the East Bay Municipal Utility District and the San Francisco Public Utilities District.
A 1983 state Supreme Court decision forced Rukeyser's agency to consider public trust values in Mono Lake and restrict water use by Los Angeles to the extent it was feasible.
Three years later, in 1986, a state appeals court in a lawsuit over permits for the Delta pumps advised state regulators they had those same powers in the Delta. However, regulators never applied them.
The lawsuit was filed by the California Water Impact Network, the California Sportfishing Protection Alliance and AquAlliance in Sacramento County Superior Court.
The lawsuit replaces a similar lawsuit filed by some of the same groups in December 2008 that was later withdrawn because of procedural problems.
Mike Taugher covers the environment. Contact him at 925-943-8257.