Sierra Cloud-Seeding : L.A. to Help Mother Nature With Snow

The city will begin cloud-seeding over the Sierra Nevada this week to increase the snowpack on its eastern side, which provides 75% of the city’s water supply, officials said Monday.

“Despite a recent storm, the existing snowpack conditions in the eastern Sierra are still substantially below normal for this time of year,” said Duane Georgeson, assistant general manager of Water and Power Department.

“Although there will be an adequate water supply for Los Angeles during 1987 due to reservoir storage, survey reports indicate the existing snowpack is only about 25% of normal for this time of year,” he said.

Stopgap Measure

The three-week cloud-seeding operation, estimated to cost $10,000, is a stopgap measure to enhance snowfall until a three-month seeding program begins in late January, Georgeson said. The longer program is estimated to cost about $40,000.

“Hopefully, this interim cloud-seeding operation will help increase the snowpack for water-supply runoff later in the year, as well as improve winter recreational opportunities in Inyo and Mono counties,” he said.

Georgeson said the December-March period has ideal atmospheric conditions and cloud formations for cloud-seeding.

The seeding will take place in a 140-mile corridor along the eastern slopes of the Sierra from Saddlebag and Lundy lakes in the Mono Basin to Cottonwood lakes in the southern Sierra near Lone Pine.

No Harmful Effects

Dry ice and silver iodide will be used to produce the snow because they have no harmful effects on plants and animals at the concentrations used in cloud seeding, Georgeson said.

“Although we anticipate our Eastern Sierra cloud-seeding efforts would increase this year’s water runoff by 5% to 10%, we are continuing to urge our customers to use water-conserving practices in the advent that this dry trend continues,” he said.

The cloud-seeding operations may also increase water inflow in Mono Lake and boost the city’s generation of hydroelectric power, he said.