An expert in California's Delta told a panel of the National Academies of Sciences on Sunday that their decisions about the largest estuary on the West Coast could alter how Californians use water.
"I view this as the thorniest water environmental issue in the West," said Jeffrey Mount, a professor at the Center for Watershed Sciences at the University of California, Davis.
The 15-member panel of independent scientists is meeting this week to examine whether the federal government should lift or modify limits on pumping from the Sacramento-San Joaquin Delta, restrictions that farmers blame for a water shortage that has left once-fertile fields to wilt.
At the center of the discussions are two environmental plans written last year by federal wildlife agencies. Both are intended to protect threatened fish by restricting how much water can be pumped from the Sacramento-San Joaquin Delta.
The restrictions, combined with a three-year drought, have forced farmers to fallow thousands of acres and cities to impose severe water restrictions.
"We're going to help point the way to the most optimal management solution that can be found," said Stephen Parker, director of the academies' Water Science and Technology Board.
The panel, requested by U.S. Interior Secretary Ken Salazar, is exploring whether there might be other ways to preserve fish. It is expected to produce a recommendation in March, followed by another year of study about the state of the Delta.
The Delta, where rivers that drain from the northern and central Sierra Nevada collect, is the hub of California's water supply. Massive state and federal pumps siphon drinking and irrigation water to more than 25 million Californians and the Central Valley farms that produce half the nation's fruits and vegetables.
But those pumps also reverse the Delta's flow in some areas, drawing in and killing the tiny Delta smelt. The flows also misdirect juvenile salmon to interior parts of the Delta, meaning tens of thousands of migrating fish may never make it to the sea.
Along with the Delta pumping, cities stretching from northern California to the Central Valley divert fresh river water that otherwise would flow into the Delta and out to the San Francisco Bay. An estimated half of the water that once flowed through the Delta goes elsewhere, altering the fragile ecosystem where hundreds of species live, Mount said.
"This may be the most invaded estuary in the world," Mount told the panel.
While state and federal water officials say the drought has been the biggest culprit in California's recent water troubles, the pumping restrictions have become a political target.