Works in Progress

California's biggest lake is a man-made accident nature keeps trying to undo

By Karen WrightNov 1, 2000 6:00 AM


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No single tale can quite do justice to the Salton Sea. This vast inland lake in the California desert is a fluid contradiction of promise and poison, a death trap teeming with life. It was created nearly a century ago, when raging floodwaters from the Colorado River tore up irrigation channels and filled up a dry basin southeast of Palm Springs. Thousands of acres of farmland were washed out and almost half a Native American reservation was submerged beneath 60 feet of water. But by the 1960s, developers had remade the accidental lake as a booming resort destination, with celebrity yachts crowding its marinas and palm-lined promenades giving views of snow-capped mountains. Beyond the sea's shores, everything from grapes to turf grass thrived in an endless growing season. Salt from the desert soil and fertilizers from the fields poured into the sea, sustaining a robust ecology of marine life.

Then cities upstream of the Salton Sea began adding municipal wastewater to the inflow, and nutrients from agricultural runoff reached critical levels. The sea began to groan under its burden of life: Epidemics spawned by overcrowding struck the millions of migratory birds that had come to depend on the sea, and excess nutrients fed noxious algal blooms that depleted oxygen in the water and left fish gasping for breath.

Yet there are still far more fish in the sea than a healthy ecosystem can bear. Steve Horvitz, the superintendent of the Salton Sea State Recreation Area, recalls the local angler who was pulling in a couple of fish per minute. When Horvitz remarked on the catch, the man said, "Yeah, slow day."

Now the Salton Sea may undergo a massive makeover to restore its health. Two years ago, federal lawmakers instructed the Department of the Interior to evaluate cleanup strategies that include salt control, fish harvesting, and bird rescues. The complexity and cost of the cleanup— as much as $1 billion— make the Salton Sea project one of the most ambitious ecological restorations ever launched in the United States. But there's no guarantee that Congress will follow through with the required funds, or that it will provide them in time. Some experts warn that, if conditions worsen as expected, all fish in the lake could expire within 15 years, taking the birds along, too.

"It's a terminal body of water, so it's like a bathtub without a drain," says Tom Kirk, executive director of the Salton Sea Authority, the local body charged with coordinating the cleanup studies. Unlike most inland bodies of water, he explains, the Salton Sea has no stream or aquifer that would help to flush it clean. Salt, nutrients, and decaying organic matter check in, but they don't check out. And the intense desert heat further concentrates the cocktail by hastening evaporation.

At present, the Salton Sea is 25 percent saltier than seawater— a level even saltwater fish have trouble tolerating. Populations of corvinas and sargos that were stocked for sportfishing in the 1950s are already falling off due to salinity. Now most of the fish in the sea— numbering in the hundreds of millions— are tilapia, a fast-breeding species that is more susceptible to low oxygen levels than to high salinity. Tilapia respond to the sea's occasional oxygen shortages with massive, malodorous die-offs.

Fish die-offs, algal blooms, and brackish smells are to be expected from any shallow, warm, living body of water that doesn't have an outlet, says Kirk. The Great Salt Lake is a case in point: After thousands of years of evaporation, it reeks, and the largest form of animal life it hosts is brine shrimp.

And even the most detached students of brine lakes became alarmed when birds began to die on the Salton Sea in droves. Hundreds of thousands of eared grebes fell prey to unknown illness in 1992; four years later, 1,130 brown pelicans succumbed to avian botulism, a common bacterial scourge of the crowded swamps and estuaries along the Pacific Flyway. The pelicans, an endangered species, continue to die in disturbing numbers each year.

As part of the new initiative, a pelican hospital has been built on the south shore, and rescue teams patrol the sea all summer, when botulism breakouts tend to occur. Managers have also launched a pilot program to harvest tilapia in commercial quantities. "The only way to remove large amounts of nutrients, phosphorus in particular, is by fishing," says Stuart Hurlbert, a limnologist at San Diego State.

But Hurlbert says the amounts of nutrients entering the sea will also have to be curbed. To that end, a local conservation group is building wetland diversions that would remove phosphates and nitrates from the New River, a major tributary. And the United States is helping to build a wastewater treatment plant in the Mexican border town of Mexicali, which dumps sewage into the river. But the sea's advocates say the plan will backfire if Mexicali reclaims the treated water, reducing the amount of freshwater that replenishes the sea.

In fact, water supply may become the most intractable issue facing the Salton Sea. Officially the sea is an agricultural sump that has no right to water from the Colorado River. Its level is maintained by drainage from irrigation districts and municipalities such as Mexicali, which have proper water rights. As drinking water becomes an increasingly precious resource in the Southwest, farmers will start selling their water to distant cities, agriculture will dwindle, and the Salton Sea will go with it, predicts environmental scientist Eugenia McNaughton of the Environmental Protection Agency's district office in San Francisco. Proposals to draw out the salt in the sea with evaporation ponds or misters still require freshwater inflows to replace the evaporated water, McNaughton points out. "You can't stabilize salinity where the evaporation rate is so high unless you bring in a source of fresh water."

Some say the most natural course of action is to let the Salton Sea dry up. But locals resist the loss of their lakefront property, and conservationists abhor the disappearance of a major stopover on the Pacific Flyway. Meanwhile, a vocal faction is lobbying for the return of a healthy, revenue-generating resort paradise. There would, of course, be a small public-relations problem. "So many people think you put your hand in and your hand's not going to come back out," Horvitz told the High Country News, a biweekly newspaper about environmental issues in the West.

Not everyone is daunted. Norm Niver, a 30-year resident of Salton City, still enjoys the many fish he catches in the Salton Sea. He swims in it too. Down the street from his house, at the West Shores Chamber of Commerce, a faded felt banner promises sea air and sun for healthy desert fun. Across the water on the northeast shore, it's standing-room-only on the state park's fishing jetty, and another angler pulls in a big orange-mouth corvina.

No single story can sum up the Salton Sea, and no one solution will save it.

For a comprehensive, well-organized overview, visit the Salton Sea Web site: www.sci.sdsu.edu/salton/SaltonSeHomePage.html.

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