Q: Tell me about Idaho Power’s seeding clouds for more rain.
A: “Idaho Power’s cloud-seeding program increases snow accumulation and provides increased generation at the company’s hydroelectric facilities,” said Brad Bowlin, spokesman for Idaho Power. “It also benefits skiers, snowmobilers, agriculture, fish and other wildlife habitat, aquifer recharge and water quality.
“The original program was established to increase snow accumulation in the south and middle forks of the Payette River watershed.”
The Payette, a major tributary of the Snake River, originates in the Sawtooth and Salmon River mountains.
“In 2008, Idaho Power expanded the program by enhancing an existing program operated by a coalition of counties and other stakeholders in the upper Snake River system above Milner Dam,” Bowlin said.
For the 2013–14 winter, the program used 17 remote-controlled, ground-based generators and one airplane for the Payette Basin.
The Upper Snake River Basin, he said, had “19 remote-controlled, ground-based generators operated by Idaho Power and 25 manual, ground-based generators operated by the coalition. Idaho Power provides meteorological data and weather forecasting to guide the coalition’s operations.”
Jackson Lake, Palisades, Grassy Lake, Island Park, Ririe, American Falls Dams and Lake Walcott comprise the Upper Snake system.
Idaho Power first contracted for cloud-seeding in the winter of 1996–97. Since 2003, it has operated its own cloud-seeding program.
Annual snowpack in the Payette River Basin increased by 5 percent to 15 percent, depending on the year, with an average increase of nearly 13 percent, Idaho Power analyses show.
“Idaho Power estimates cloud seeding in the Payette provides nearly 200,000 additional acre-feet of water for the Hells Canyon Complex each year. That amount of water can generate approximately 100,000 megawatt-hours, or enough to power roughly 7,900 homes.”
By introducing more ice nuclei into winter storms with water vapor and the right temperatures, those tiny silver iodide particles increase precipitation, said Bowlin.
“Idaho Power uses two methods to seed clouds: ground generators at high elevations, and airplanes that release special flares into storm clouds. We work closely with federal, state and local authorities to ensure our cloud-seeding operations comply with all relevant environmental and land-use guidelines,” he said.
Silver iodide has been used for winter cloud seeding in 11 of the 17 western states for decades, and no harm to the environment has been documented.
Savings are passed on to Idaho Power’s customers. In 2006, for example, high stream flows augmented by cloud seeding helped decrease customers’ rates by an average of 19.3 percent.
The cloud seeding season runs from Nov. 1 through April 15.
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