L.A. water supply looking good after highest snow levels in a decade

The Los Angeles Department of Water and Power (LADWP) recently announced that this season's persistent storms dropped the highest snowpack in a decade in the Eastern Sierra watershed, guaranteeing an ample supply of less expensive, high-quality water for the coming year.

LADWP officials said the final snow surveys of the winter season, which ended April 1, indicate that the Eastern Sierra has water content equal to 167 percent of normal -- marking the first above-normal snowpack since 1999 and the highest snowpack since 1995.

"This is very good news for the city's water supply," said Mayor Jim Hahn. "With such high snow levels we can be sure that the LADWP will be able to maximize the amount of water it can deliver to the city through its own aqueduct system, while meeting its many environmental commitments in the Eastern Sierra. This will minimize the amount of more expensive water we must purchase from other sources."

As an added bonus, the deep snowpack will enable LADWP to generate about 10 percent more clean, renewable hydroelectricity from its 14 hydropower plants located along the Los Angeles Aqueduct. LADWP power system officials said that represents an additional 45,000 megawatt-hours per year, enough power for about 7,000 households.

LADWP General Manager Ron Deaton emphasized that the Eastern Sierra provides the city's most economical water supply as well as the highest quality, thanks to the Los Angeles Aqueduct. Built in 1913 by William Mulholland, the aqueduct brings Eastern Sierra snowmelt from the Owens Valley south to Los Angeles. LADWP will be celebrating Mulholland's 150th birthday later this year.

However, Deaton also cautioned that after five dry years, one season of above-normal precipitation doesn't mean Angelenos should stop conserving water. "Our customers have done a great job of water conservation. Thanks to their efforts, Los Angeles consistently has one of the lowest water consumption rates per capita in the state. Customers use the same amount of water as they did 20 years ago, despite a population increase of more than 700,000 people," Deaton said.

During an average year, about 50 percent of the city's water comes from the Eastern Sierra. In recent years, however, water content levels have been below normal due to dry weather. For the last six years, the snowpack has averaged 71 percent of normal. The average amount of water runoff from the Eastern Sierra has been nearly 22 percent below normal for that period.

In the past, the Los Angeles Aqueduct has provided up to 75 percent of the city's water needs. Recent agreements and mandated endeavors have resulted in the LADWP providing almost one-third of the water it historically diverted to Los Angeles to projects in the Eastern Sierra, including Mono Lake and the Owens Lake Dust Mitigation Program.

LADWP hydrographic crews based in Bishop and Independence in the Eastern Sierra skied, snow-shoed and drove snow cats into the backcountry in late March to take the year's final measurements of snow depth and water content at backcountry measuring stations. LADWP has been conducting snow surveys at the same sites for more than 75 years.

LADWP snowpack measurements will contribute to a statewide Cooperative Snow Survey Program that determines how much water will be available this summer to farmers, wildlife, reservoirs and hydropower plants throughout California.

This article originally appeared in the 04/01/2005 issue of Environmental Protection.

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