Water has begun flowing down 64 barren miles of the San Joaquin River in what is being touted as California's most ambitious effort to bring back long-lost native salmon.
The floodgates of the colossal Friant Dam outside Fresno were opened last week so researchers can study how the water flows down California's second longest river.
The releases, which will continue until Dec. 1, will accelerate this spring until enough water is flowing down the parched riverbed to fill an Olympic-size swimming pool in less than a minute.
It is all part of a historic agreement reached after two decades of legal wrangling over efforts to bring back the salmon that were wiped out a half-century ago when the 319-foot dam was built.
"The resumption of restoration flow releases down the San Joaquin River, even at a fraction of its once mighty flows, is a monumental event," blogged Monty Schmitt, a senior scientist with the Natural Resources Defense Council, which is a party to the agreement along with the Friant Water Users Authority and the federal government.
"These flows and the restoration effort are an example of how farmers, fishermen, environmentalists, and state and federal agencies can work together to implement real solutions to California's conflicts over water resources," Schmitt wrote.
The Friant Dam was built in the 1940s so that 1 million acres of farmland could be irrigated. It plugged the river gorge and held back nearly the entire flow of water, causing 64 miles of the river to completely dry up. The native chinook - once so plentiful that farmers used to scoop them out of the river to use as hog feed - disappeared by the early 1950s.
Environmentalists have characterized the draining of the San Joaquin as one of the most egregious examples anywhere of habitat destruction to quench civilization's thirst for water.
The battle to restore the river began in 1988 when the defense council and other environmental groups sued the U.S. Bureau of Reclamation and other federal agencies to prevent renewal of long-term water contracts with Friant-area irrigation districts.
The releases into the river mark the second time in more than 60 years that water has flowed between the banks of the entire San Joaquin. Smaller pulses of water were released last October and November.
Over the next few months, Schmitt said, water temperatures, velocity, channel depth and bank stability will be studied. Problem areas will be fixed in preparation for 2012, when the first salmon are expected to be reintroduced.
Year-round flows are expected to begin over the entire 150 miles between the dam and its confluence with the Merced River in 2014. Even when completed, Schmitt said, only about 18 percent of the historic flow of the river will be restored.
