State’s Aqueduct Will Be Closed to Repair Leak

State Water Resources Director David N. Kennedy disclosed Thursday that the California Aqueduct--the state’s water lifeline--will be shut down soon to repair a leak related to the recent El Nino storms.

Kennedy said it is unlikely that water delivery to customers in Southern California will be disrupted during the 45 to 60 days it takes to fix the damage near the San Joaquin Valley town of Los Banos.

Describing the work as an “emergency” step, Kennedy said the repairs will start in the next few days in anticipation of more punishing El Nino storms forecast for March and April.

“When you’ve got something broken like this in a very vital facility, you’d better get it fixed because you don’t know what else might happen to you,” Kennedy said.

In the Sierra Nevada, where the snowpack furnishes most of the water that Californians consume during the dry summer and fall months, near-record accumulations of snow have piled up.

Officials said records may be set, surpassing even those of 1983, when the snowpack hit 220% of average on April 1, officials said. The level now is about 170% of average.

A heavy runoff caused by unseasonably warm and intense spring storms could put new pressure on the aqueduct.

The 444-mile-long aqueduct transports water from Northern California and pumps it over the Tehachapi Mountains to Southern California, where it serves Los Angeles and other coastal cities and the Inland Empire.

Typically, the aqueduct moves between 2.5 million acre-feet and 3 million acre-feet of water a year for municipal, industrial and agricultural users.

The repairs will occur along a 500- to 1,000-foot-long stretch of the aqueduct north of the San Luis Reservoir. It recently started leaking again after being patched in August.

Kennedy said that gypsum, a naturally occurring element in the soil, has become so saturated by winter rains that it is rapidly dissolving. This weakens support for the canal and causes it to leak.

“All the ground is saturated. It tends to exacerbate any seepage condition you’ve got,” Kennedy said. “We’ve got to fix this. We think it is an emergency.”

Before it was patched in August, Kennedy said, the canal leaked 800 gallons a minute. Small leaks started again a couple of weeks ago, but quickly increased from half a gallon a minute to 20 gallons a minute, he said.

Kennedy said repairs will cost up to $2 million and involve rolling out thick sheets of a heavy “membrane” material that then will be coated with layers of concrete.

During the shutdown, the downstream San Luis Reservoir, which is full, will be tapped to offset the loss of aqueduct deliveries, Kennedy said. In turn, the reservoir is expected to be replenished by flows from the heavy rains.

There is so much water in the Sierra snowpack and reservoirs, Kennedy said, that customers of the state will receive all the water they ask for this year.

“There’s going to be enough water for everybody this year,” Kennedy said. He noted that it will be the third straight year in which water contractors will receive full supplies.

But Kennedy warned that if the predicted storms for March and April are significantly warmer and more intense than the El Nino storms of January and February, new flooding from rapid snowmelt in the Sierra could occur.

“What you hope is that you are not going to get the kind of intensities we’ve had in January of last year, or February and March of 1986,” he said.

In those years, Northern California suffered devastating floods when closely spaced, unseasonably warm rains, dubbed the Pineapple Express, swooped down and prematurely melted much of the snowpack.

Kennedy said officials are concerned about possible late spring flooding in the upper San Joaquin Valley, where flood control systems are not as developed as they are in the Northern California watersheds.

During the huge El Nino winter and spring of 1983, floods inundated vast tracts of farmland near the Sacramento-San Joaquin Delta. “We are probably going to have flood control operations in the San Joaquin [as late as] June,” Kennedy said.

Meanwhile, customers of the federal Central Valley Project, chiefly farmers in the San Joaquin Valley, also are expected to receive virtually all of the water they need, said Jeff McCracken of the U.S. Bureau of Reclamation.

McCracken said that although environmental restrictions for fish and wildlife protection will cut San Joaquin Valley customers to 80% of what they had agreed to, the remaining 20% probably would be made up from captured late spring flood flows and from water sales and trades among customers.

“They know where the water is, and they know how to buy water on the open market,” he said.