REPORT: Cost estimates will include four options; lake's fish population is dwindling.
01:22 PM PST on Friday, March 26, 2004
By JENNIFER BOWLES / The Press-Enterprise
LA QUINTA - Despite a muddy floor, the Salton Sea can support an 8-mile-long dam that would slice the lake in half, but ultimately prevent an ecological collapse at the site that harbors 400 bird species, an engineer said Thursday.
Richard Davidson spoke for 15 civil engineers and dredging specialists who gathered earlier this week in Ontario to evaluate the dam proposal. He told the Salton Sea Authority that construction in the seismically active region, and in the extremely salty water, would be challenging but possible.
"There are soft soils there, but they are almost identical to soils across the Great Salt Lake," where similar structures have been built, he said. "So it's not something we should be fearful about. We just have to design around it."
Davidson, who works for Denver-based URS Corp., said the panel of specialists would come up with cost estimates for four concepts. They include scooping up the top 30 feet of the muddy bottom and pouring it into a rock-fill structure to create the dam, or using grout fill and concrete to create a sandstone-like dam.
Salton Sea Authority members welcomed the panel's findings.
"I think it's very encouraging," said Andy Horne, the board's president and member of the Imperial Irrigation District.
The nine-member authority is made up of water agency officials and lawmakers from Riverside and Imperial counties, where the sea sits, and the Torres-Martinez Indian tribe. The group is struggling to maintain some control over the lake's restoration after a recent state takeover.
The board also got some bad news from the specialists. The number of fish in the sea is decreasing, said Jack Crayon, associate biologist with the state Fish and Game Department. Crayon said surveys of tilapia, corvina, sargo and croaker show a "dramatic decline in all species." He said no single factor could be blamed, but if the sea is restored, the numbers should return.
The dam is a key element in a restoration plan that would prevent the sea from shrinking and becoming saltier under an impending transfer of water from surrounding farmland to urban San Diego. Farm runoff helps sustain the sea.
Under the "North Lake" concept, the dam would allow the northern portion of the sea to remain as an ocean-like lake for fish-eating birds, such as pelicans, and migrating birds on the Pacific Flyway. Much of the southern half would dry up and be capped to prevent wind from stirring up air-polluting dust.
Wetlands on the northern and southern edge would provide nesting grounds.
Under the plan's latest version, unveiled recently by U.S. Rep. Mary Bono, R-Palm Springs, hiking and biking trails, off-roading areas, camping and golf would play a central role in boosting the sea's recreational and economic opportunities.
Salton Sea Authority members also took up the issue of retaining some power over the sea they have worked to protect for 11 years. Legislation last fall transferred restoration responsibility to the state as part of a complicated water deal.
Board members voted unanimously to send a memorandum of understanding to the state that would clarify their respective roles and responsibilities.
They also said they would seek new or amended legislation to protect their power.
Reach Jennifer Bowles at 909-368-9548 or jbowles@pe.com
