The experiment, called the "Two Gates" project, comes up at water rallies and political strategy sessions among San Joaquin Valley lawmakers who support the idea. They hope it will bring more water to 25 million residents and millions of farmland acres.
The gates -- which have not been fully detailed publicly -- would be mounted on sunken barges in two large channels in the central part of the delta. They would prevent turbid water from flowing south toward the pumps. The adult smelt tend to follow the turbid water, scientists said.
With the gates closed, the pumps could continue sending water south without harming the fish.
But there are serious hurdles ahead. The public hasn't seen any details. There is no funding yet for the $26 million project. And environmental analysis of such projects can take years.
Still, farmers and city officials hope the gates could be installed by December. A detailed plan might be available for public review in the next several weeks.
Politicians are pressuring government wildlife agencies to analyze it quickly. Water officials hope to tap federal stimulus money.
That's not enough to bring environmentalists and fishing organizations on board.
"This thing is an embryo right now," said Bill Jennings, chairman of the California Sportfishing Protection Alliance in Stockton. "I don't even know what we're talking about."
The experiment is the brainchild of state and federal contractors -- farm and city officials -- who are coping with reduced water deliveries for smelt protection. Further pumping cutbacks are expected for other suffering species, such as Chinook salmon and green sturgeon.
The delta's pumps, long considered a factor in dwindling fish populations, send water into San Luis Reservoir. San Luis storage this summer is less than 30% of average because of delta pumping restrictions and the three-year drought.
The California Department of Water Resources and the U.S. Bureau of Reclamation are studying the Two Gates proposal, which water contractors began assembling last year as water cutbacks continued.
City and farm contractors developed the idea with their own consultants and presented it to state and federal officials this year, said Tom Birmingham, general manager of the Westlands Water District.
Westlands and Metropolitan Water District of Southern California were among the water contractors that pushed the idea.
Michelle Light, state water resources regional planning officer, said the engineering and design work have progressed well. She said the state's analysis is moving quickly because of water shortages and the dwindling smelt population.
Katherine Kelly, chief of the federal reclamation bureau's Bay Delta office, added that there would be a July meeting of scientists to discuss the details of the proposal. No date has been scheduled yet.
Even if the project is completed by December, Birmingham cautioned farmers and others not to consider Two Gates a guarantee of increased water supply.
"There is a perception that construction of this project will lead to an increase of water," he said. "This really is an experiment."
Two Gates would be an innovation compared to previous solid barriers that could not be easily opened and closed. Such solid barriers have been used in the past to protect fish, maintain water quality and keep water at desired levels in the sprawling river delta, according to the water resources department.
Dan Nelson of the San Luis & Delta-Mendota Authority, representing west-side farmers, said Two Gates is flexible by comparison. Besides opening and closing, the barges can be moved to see if they work better in other locations.
Rep. George Radanovich, R-Mariposa, said Two Gates has strong political support from lawmakers on both sides of the aisle. He said he will continue to pressure wildlife agencies for a quick turnaround on their study of the project.
