LOS ANGELES: A plan to save California's largest lake calls for possible fixes including constructing dams and berms to isolate areas high in saline.

After two years of often intense debate and research, state officials have finished an environmental report with ideas for saving the 55-kilometre long Salton Sea. The lake lies just north of El Centro in Southern California.

The lake and its plant and animal life have been suffering from a drop in water levels and increasing salinity. The Salton Sea is a key North American stopover for several species of migrating birds, including several types of geese and the endangered Yuma Clapper Rail.

The report, prepared by the water resources department and the Department of Fish and Game, was released last week.

"We don't have all the answers. There is still a lot of uncertainty out there as far as water quality issues," said Dale Hoffman-Floerke, chief of the Colorado River and Salton Sea office for the Department of Water Resources. "But I think we've done a pretty good job ... with the information we have."

Suggestions, called "alternatives" in the report, include building dams and berms at a cost ranging from US$2.3 billion to US$5.9 billion to isolate areas of the lake where salt content is at its highest, and thus less likely to sustain plant and animal life.

Others include fostering habitats along the shoreline and measures to increase air quality by preventing more of the shoreline from being exposed.

Studies have shown that if nothing is done, the lake could shrink by more than 60 per cent in the next 20 years, exposing dusty shoreline in a farming region already plagued by worsening air quality.

"It's a huge public health threat," said Michael Cohen, senior associate with the Pacific Institute, an Oakland-based think tank that has studied the lake. "Obviously we need to protect the birds that rely on the Salton Sea, but certainly people are a critical concern."

The Salton Sea, which stretches across the Imperial and Riverside county line, was created in 1905 when floodwaters broke through a Colorado River irrigation canal.

Today, it faces an uncertain future, largely because of agreements to transfer water from the area to more heavily populated San Diego. Experts say the lake, already dependent on water flows to balance high salinity, is on a perilous track.

Cohen, who sits on the Salton Sea Advisory Committee, praised the state for completing the report. But he expressed disappointment with the offered alternatives.

"None of them are really going to fit the bill," he said. "The way they are put together right now is not really the answer. But we could use the pieces and put them together in a different way, a way that is going to get local and environmental support."

One of the largest stakeholders in the water body is the Salton Sea Authority, which is comprised of local officials.

Its proposed alternative, which is included in the state report, would create a recreational portion in the north with key habitat areas in the south. It would also feature a 4,400-hectare freshwater reservoir.

After a 90-day public comment period, a "preferred alternative" will be submitted to the state Legislature.

(China Daily 10/24/2006 page14)