State Sets New Safeguards for Mono Lake : Environment: Biologist who studied the area 50 years ago hails the decision, which cuts off a longtime source of L.A. water.

Fifty years ago, a young state biologist named Eldon Vestal fell in love with Mono Lake. Just out of college, he meticulously studied the Eastern Sierra lake made famous by Mark Twain, took measurements of its tributary streams and documented plants and animals that depended on it.

When transferred to another part of the state, Vestal packed his notes away in cardboard boxes. They would not be opened for four decades, until environmental lawyers sought proof of the damage inflicted on the ecosystem by diverting the streams to the city of Los Angeles.

The yellowed field notes became critical evidence in lawsuits against the city that ultimately led Wednesday to a decision by the State Water Resources Control Board to order new environmental protections for the ancient brine lake east of Yosemite National Park. The order effectively brings to an end, at least for the next 20 years, any substantial diversion of water from the Mono Lake basin to Los Angeles, 300 miles south, and defuses one of the state’s most protracted environmental fights.

Minutes before the board recorded its 5-0 vote, the biologist, now hobbled by age and hard of hearing, made his way to the front of the room to talk about protecting Mono Lake, a step he had dreamed about but thought would never happen.

“The city of Los Angeles was a tremendous political power over the years,” Vestal said, “and challenging it seemed like grabbing for a bite out of the moon.”

Indeed, environmentalists and politicians characterized the board’s action not only as one of their greatest victories but as a decision that symbolized the state’s new attitudes toward water resources and their limitations.

“Years ago, the growing needs of a burgeoning populace seemed to eclipse concerns about a small lake in the eastern Sierra Nevada and the wildlife and communities that depended upon it,” said Sen. Tim Leslie (R-Carnelian Bay), who represents the Mono Lake area. “Today, the state stands ready to recognize the failings of the policy we set years ago and make amends for the decisions of our past.”

Mono Lake, a landlocked body of salt water surrounded by high desert and formations of volcanic debris, is the nesting home to many bird species, including the California sea gull. Mark Twain wrote in his book “Roughing It” about spending time on one of the lake’s nesting islands in the late 1800s. “Half a dozen mountain brooks flow into Mono Lake, but not a stream of any kind flows out of it,” Twain wrote.

Acting on a staff report that blamed decades of stream diversion for causing extensive environmental damage, the board ordered that Mono Lake be allowed to rise to a new elevation of 6,391 feet, 16 feet higher than the average level it reaches today.

Until the lake rises at least two feet, the board directed that the city of Los Angeles be prohibited from taking any water from the streams that tumble down from the Sierra. After that, the board said, Los Angeles could take minimal amounts, probably averaging no more than 12,000 acre-feet a year.

The board estimated it would take 20 years for the landlocked lake, surrounded by high desert and ancient volcanic debris, to rise to its targeted level. Once that occurs, Los Angeles can only divert an average of 30,800 acre-feet annually, less than a third of what the city once took from the region.

Environmentalists, relying in part on historical evidence provided by Vestal’s notes, have argued in lawsuits and in nationwide publicity campaigns that those diversions had caused the lake to drop 26 feet and endangered the habitat of dozens of species.

Facing certain defeat, Los Angeles officials announced early Wednesday that they would accept the board’s decision and had reached an agreement with environmentalists to end 16 years of litigation over Mono Lake.

City Councilwoman Ruth Galanter, a longtime advocate for the restoration of Mono Lake, said the city’s action reflected a change of attitude among officials and their determination to increase urban water supplies without harming the environment.

“Now I think virtually everybody recognizes that conditions today are different than they were when (William) Mulholland was out building the water system,” she said, referring to the water engineer who spearheaded efforts to use water from the eastern Sierra to fuel Los Angeles’ growth.

Department of Water and Power General Manager Bill McCarley said the city would rely eventually on reclaimed waste water to replace some of the water formerly taken from Mono Lake. But he acknowledged that the board’s decision will cause the city to continue to rely heavily on the Metropolitan Water District.

He acknowledged that the permanent loss of Mono Lake water would drive up costs if the city is forced to use more expensive water to replace it.

“I think everybody in the state has to realize that water as a resource, as a commodity, is not going to be as inexpensive as it has been,” he said.

The city’s new attitude drew praise from U.S. Bureau of Reclamation Commissioner Daniel P. Beard, who said it had almost come too late.

“All parties have come to the realization that many serious environmental mistakes were made when we constructed the water projects upon which our urban and agricultural sectors now depend,” he said. “Not surprisingly, some have been reluctant to confront those mistakes. We almost lost Mono Lake because of that reluctance.”