The San Joaquin River is now flowing from Friant Dam to the Pacific Ocean, reaching the first milestone in a plan to bring back Chinook salmon.
Restoration of the state's second-longest river should achieve another major goal this summer - a continuous run of water to the ocean even during the dry months of August, September and October.
It has been decades since the river flowed continuously from the dam to the ocean during spring, summer and fall without the help of an unusually wet year.
The connection with the ocean happened about two weeks ago, officials said.
"This is a big moment," said Monty Schmidt, senior water resources scientist for the Natural Resource Defense Council, a national environmental watchdog with an office in San Francisco. "It's a big step toward having a living river again."
The San Joaquin had been mostly dry for about 60 miles over the last six decades after Friant was built to provide irrigation water for farmers and flood protection for surrounding residents.
The NRDC filed a lawsuit in the late 1980s to revive the river. Nearly two decades later, environmentalists, farmers and the federal government signed an agreement to restore the river.
Now, in the first full year of the restoration, east San Joaquin Valley farmers will lose up to 230,000 acre-feet of water to keep the flow going. It amounts to 18% of the water they have been getting after an average season.
Farmers are hoping to get some of the restoration water back after it flows down the river.
Officials may be able to work out water trades with other districts that use the restoration flow this year, said Ron Jacobsma, general manager of the Friant Water Users Authority, representing 15,000 east-side growers.
Jacobsma also said some restoration water may reach the Sacramento-San Joaquin Delta, where officials could attempt to pump it back to east-side farmers through canals. But that might prove difficult because federal officials have been forced to cut back pumping to protect threatened fish.
The water releases are considered experimental at this point in the restoration as government officials study such aspects as water temperature, which needs to be cool for salmon, and seepage, which could destroy crops on surrounding land.
The experimental flows will end Dec. 1 and pick up again in 2011, federal officials said, though an exact schedule has not been settled yet.
Salmon will be reintroduced by Dec. 31, 2012. The restoration cost over the next several years is estimated between $250 million and $800 million.
A lot of that money might be spent on preparing the river channel about 99 miles downstream of Friant Dam. At the moment, the river runs into a massive channel called the East Side Bypass, designed to carry flood water.
Near the bypass, many miles of the native river channel have been closed off for decades, and in places crops are grown right up to the banks. Officials need to pick either the bypass or the native channel for the river's route.
If the native channel is used, it would have to be widened and deepened. If the bypass channel is used, it would have to be redesigned with trees and shrubs along the banks to help keep the water cool for the fish.
For now, the reconnection of the river between Friant and the ocean is getting a lot of attention.
"It means everything," said Chris Acree, executive director of Revive the San Joaquin, based in Fresno. "This is a turning point on a restoration that can work for everybody."