A high-water mark for Mono Lake

There was a time when it was hard to find yellow warblers at Rush Creek.

But on a recent bright and sunny morning, a yellow warbler plunged through a gap in a stream-side cottonwood forest, flying back to the nest where her chicks were hiding. Suddenly, she was stopped in midair, tangled in a mist net.

Field biologist Chris McCreedy found the bird in his snare a few minutes later. “Hi there, sweetie,” McCreedy said as he set to work. He untangled the bird, recorded its vitals -- it was a 2-year-old female that weighed 10 grams, about as much as a ballpoint pen -- and gently clamped an identification band to one of her legs.

Then he opened his palm and released her back to Rush Creek, a major tributary to Mono Lake in the eastern Sierra and the focus of an agonizingly complex and decades-long effort to heal a vast wilderness devastated by Los Angeles’ insatiable thirst.

Now, 14 years after the city was ordered to reduce the quantity of tributary water it had been diverting into the Los Angeles aqueduct since 1941, Rush Creek has among the highest concentrations of yellow warblers in California -- roughly three pairs per 2 1/2 acres.

“Restrict grazing and bring back the water and things really start hopping,” McCreedy said.

That’s the good news. Orchestrating the restoration continues to be a challenging process for the https://https: www.monolake.org/ “> www.monolake.org/ , a nonprofit group of environmentalists and concerned citizens organized in 1978 to save and protect a bowl-shaped ecosystem roughly half the size of Rhode Island.

Nonetheless, Geoffrey McQuilkin, executive director of the 16,000-member group, said he is often asked, “Why is the Mono Lake Committee still around? You got the water you needed years ago. Isn’t Mono Lake saved?” His stock response: “We still have a long way to go.”

Over the years, the committee has stopped city water diversions, potentially damaging highway widening projects and proposed lake-shore development. But its biologists still can’t explain why Rush Creek’s trout are not growing as large as expected.

Then there are the endangered willow flycatchers, whose population soared with the return of Rush Creek’s riparian vegetation but who are now being hit hard by an unforeseen threat: nest-invading brown cowbirds attracted by the rising brreet songs of the flycatchers’ mating rituals.

Before the tributary streams were diverted, flycatchers were commonly found in what was once a lush expanse. Flycatchers began showing up again around 2000 but in far fewer numbers. Now, they are in dramatic decline statewide because of habitat loss and competition from cowbirds.

“I’m so worried about this population of about 10 flycatchers going extinct,” McCreedy said, “that I’ve been going around town telling people to keep cowbirds away from backyard bird feeders.”

Metaphorically speaking, the nearly million-year-old alkaline Mono Lake at the base of the jagged eastern escarpment of the Sierra Nevada couldn’t be farther from the congested subdivisions surrounding Los Angeles. But that’s where the water from four of Mono Lake’s five tributary streams has been going since 1941.

By the late 1970s, the environmental degradation in the region just east of Yosemite National Park and about 350 miles north of Los Angeles was on full view. Tributary streams dried up. The lake level had dropped more than 40 vertical feet and the water had doubled in salinity, leaving behind smelly salt flats scoured by choking dust storms. The increasingly salty water threatened to kill brine shrimp, a favorite food of the estimated 50,000 California gulls that breed here each year.

Further decline, the committee warned, would transform Mono Lake into an “ugly sump surrounded by a bathtub ring of sterile white alkali encrustments.”

The sex life of gulls became a touchy political drama for Los Angeles when a declining water level revealed a land bridge connecting an island rookery to the shore, allowing coyotes to pad across and feast on the birds and their nests. The Army Corps of Engineers tried to blow up the land bridge with dynamite, but the muck only exploded sky high, then fell back in place.

Formal protests began with a lawsuit filed in Mono County Superior Court in 1979 against the Los Angeles Department of Water and Power by the Mono Lake Committee, Audubon Society and three local residents. The lawsuit alleged violations of public trust and creation of a public and private nuisance by the exposing of 14,700 acres of former lake bed.

In 1983, the U.S. Supreme Court let stand a California Supreme Court ruling that environmentalists have the right to challenge the amount of water that Los Angeles imports from tributaries of Mono Lake. The California State Water Resources Control Board later ordered minimum flows restored for all diverted streams, while still allowing the agency to divert some water for consumption in Los Angeles.

This year, as the committee celebrates its 30th anniversary, Mono Lake, while still far from its historic natural conditions, is on the mend.

On a recent weekday, the northwest corner of Mono Lake reflected the alpine peaks beyond as migrating Wilson’s phalaropes -- making a pit stop to bulk up during their 3,000-mile journey to Argentina -- probed its shallows to breakfast on a species of brine shrimp found no place else. California gulls snapped at clouds of tiny black alkali flies along the shoreline. Ospreys surveyed the placid lake from massive nests of sticks on moon-like tufa towers, strange formations built up from deposits of limestone from freshwater springs.

Amateur naturalist Gary Suttle, 62, of San Diego, called it “a good day for dragonflies and damselflies.” Armed with a butterfly net in thigh-high grass about 20 yards from the water’s edge, he said, “This place has changed a lot since I was here last about 10 years ago. The water level has risen, and there are more springs and flowers and insects.

“It’s great to be on the side of creative forces generating new life instead of destroying it,” he added. “It’s a fantastic example of human beings at their best.”

Don Banta, 80, who grew up in the Mono Lake area, put it another way: “I feel pretty darn good about the Mono Lake Committee,” he said. “They kept my lake from turning into a muddy slumpy slough.”

But the water in Mono Lake remains 34 feet below its pre-diversion level, and it still has 8 vertical feet to rise before it reaches the target of 6,391 feet above sea level. That was set by the Water Resources Control Board, and if the mark isn’t hit by 2014, the panel will hold a hearing on the matter.

This year, the lake level is expected to rise a foot. But as nearly always seems to be the case with Mono Lake, each advance comes with a setback; the water level is expected to also fall a foot by year’s end.

“We can feel a whole lot better than we did in 1978,” said McQuilkin, the committee’s executive director. “But environmental issues are not black and white. We have to be patient. Mono Lake will always be a work in progress.”

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louis.sahagun@latimes.com

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A look at Mono Lake

Take a video canoe trip through the recovering ecosystem of Mono Lake 14 years after Los Angeles was ordered to reduce water diversions. See resurgent Rush Creek, yellow warblers and other wildlife at latimes.com/california.