Rescue for a River

Alandmark court decision promises to bring new life to one of California’s major rivers, the San Joaquin, which rises in the High Sierra near Mammoth Lakes and gives its name to the farm-rich San Joaquin Valley. The ruling also could mean better water quality for Southern California residents.

The decision of U.S. District Judge Lawrence K. Karlton declares that the U.S. Bureau of Reclamation illegally takes so much water from the 350-mile-long San Joaquin each year that the river dries up in two major stretches, destroying what once was “one of the largest Chinook [salmon] runs anywhere on the Pacific Coast.” That, it said, violates a 1937 state law requiring dam operators to allow enough downstream flow to maintain existing fisheries.

The water stored behind the Friant Dam northeast of Fresno goes to irrigate about 1 million acres of crops along the east side of the San Joaquin Valley. About 90% of the annual average flow of about 2 million acre-feet -- enough to serve 4 million households for a year -- goes to farms and evaporation.

The diversion doesn’t affect just salmon. By the time it reaches the Sacramento-San Joaquin Delta, the San Joaquin River, although fed fresh water by tributaries, is heavily polluted by the salt-laden runoff from irrigated farmlands. The Metropolitan Water District, which wholesales water throughout Southern California, is concerned about water quality in the delta, a major source of this area’s water.

Karlton has yet to declare an alternative water source for the farmers. But the proposed restoration could provide a valuable example for other streams where dams and diversions have wiped out fish populations. Karlton said the needs of the water users must be considered in the court’s ordering of a restoration program.

For four years, environmentalists and farmers negotiated a proposed restoration plan. Those talks broke down over differences on how much water should remain in the river. But the Central Valley’s complex plumbing system could allow for transfers of water from other areas to ease the effect on farming.

Karlton noted that, before the dam was built, so many salmon migrated up the river in the spring it sounded like a waterfall. That’s not likely to happen again, but at least the San Joaquin might once more actually flow from the mountains to the sea.