Two events this week, at the California Supreme Court in San Francisco and in a small meeting room in Bishop, portend changes in the arrangement that lets Los Angeles take about 90% of its water supply from Mono Lake and eastern Sierra streams.
In San Francisco, the Supreme Court in effect said Los Angeles has been lucky to get away with diverting Sierra snowmelt before it reaches Mono Lake, the landmark salt lake that is slowly drying up east of Yosemite National Park.
Damage to Mono Lake itself was not the issue. The ruling Wednesday came on an appeal that involved the city taking water that trout need in order to thrive in streams above the lake. But the decision could force Los Angeles to leave much more Sierra water to flow unmolested down the streams and into Mono Lake.
Groups that have fought to save the lake and the trout by challenging Los Angeles' long-held water rights savored the ruling, saying that it turns a new page in the history of water allocation in California.
"This helps correct a half-century of injustice in the eastern Sierra," said Martha Davis, executive of the Lee Vining-based Mono Lake Committee.
The Supreme Court order makes it clear that Los Angeles must obey state laws that say water cannot be taken from rivers and streams if fisheries will be destroyed. Los Angeles had argued that it is exempt, but a state appeals court ruled last year--in overturning a Sacramento Superior Court judge--that Los Angeles' diversions from the Mono Lake area must comply with the law. Los Angeles then appealed to the Supreme Court.
As far as Los Angeles is concerned, this week's Supreme Court ruling requires state officials to rewrite the license that allows the city Department of Water and Power to divert flows from Rush, Lee Vining, Walker and Parker creeks, upstream from Mono Lake. The new license would explicitly ban water diversions that hurt the trout fisheries.
Los Angeles takes, on the average, about 100,000 acre-feet a year in Mono Basin water into the Los Angeles Aqueduct. (An acre-foot is an acre of water a foot deep, roughly enough to meet the needs of a family of four for a year.) There was disagreement Friday about just how much DWP water practices would change in the aftermath of the decision.
Davis said the ruling could lead to Los Angeles leaving behind as much as half of the water it has taken historically from Mono Lake streams. The increased flow would be most of what scientists say is needed to keep the lake surface above the elevation of 6,377 feet, the level needed to prevent further damage to several species of lake wildlife and prevent dust storms, she said.
"This is water the city of Los Angeles never had the right to divert in the first place," Davis said.
Barrett McInerney, Los Angeles attorney for California Trout, a sportfishing group, said the decision is even more sweeping in its impact on the California water scene and could lead to wholesale changes in water delivery contracts in the San Joaquin Valley.
However, Patrick Flinn, a Palo Alto attorney who represented the National Audubon Society in the case, said the decision applies only to Los Angeles' operations in the Mono Lake basin. Even there, he said, the short-term effect on streams may be minimal.
Already Releasing Water
Los Angeles is already releasing about 17,000 acre-feet down trout streams under two unrelated court injunctions involving Mono Lake and its feeder creeks. If Los Angeles can prove to the state Water Resources Control Board that the export of water south does not hurt the fish, some diversions may continue, Flinn said.
"So there is a good chance it won't change the day-to-day operations of the DWP at all," Flinn said.
DWP officials had argued to the Supreme Court that the ruling could have sweeping impacts, and were not pleased that, after nearly 50 years of using Mono Basin water, their supply is threatened with a severe cutback.
"Presumably we will lose some significant quantity of water, but I'm not sure we know how much," said Duane Georgeson, DWP assistant general manager.
The ruling could also have a domino effect on other water supplies in the state, because Los Angeles could make up the lost water from the Mono Lake area by taking more of its share from the State Water Project, which brings snowmelt from the western slope of the Sierra south by way of aqueducts that start at the Sacramento-San Joaquin Delta.
Los Angeles also got bad news from Inyo County, just south of the Mono Lake area, where most of the city's water supply is collected from the Owens River system.
Strong Inyo Opposition
Public hearings in the last week have found strong Inyo County opposition to a proposed agreement between county officials and Los Angeles to allow more ground water pumping in Owens Valley.
The proposed agreement, heaped with praise by Los Angeles and Inyo officials when it was unveiled last month, would have set up a scientific effort to measure any environmental damage from the pumping and would shut down wells causing harm. But the plan has been harshly attacked at well-attended meetings, the largest and most vocal occurring this week in Bishop.