Cloud seeding plan for range stirs fears
Will creating more snow in Winds hurt ecosystem?
By Cory Hatch
January 4, 2007
A proposed cloud seeding experiment in the Wind River Range that officials say could help solve water shortages is ill-advised according to conservation groups who worry about the project’s proximity to the Bridger Wilderness.
The experiment, which would be conducted by the National Center for Atmospheric Research, is designed to determine how well the technology works to produce more snowfall. Researchers would use 12 generators strategically placed in the Bridger-Teton National Forest near the Wind River Range in addition to five generators that are currently in place on private and state lands. The Bridger-Teton expects to start the public-involvement process on the project this month.
The five-year study could open the door for a permanent cloud seeding operation that officials say would help agriculture, fisheries, hydropower, municipal water supplies and other forms of water use. Researchers finished a similar experiment in the Star Valley area in the fall of 2006.
Conservation groups oppose the study, which they say could affect animal and plant ecosystems as well as deprive downwind locations of much needed precipitation. They also question whether the Wilderness Act, which protects the Wind River Range as a place to be preserved in its “natural condition,” would allow cloud seeding.
Process helps snowflakes form
The experiment would make use of silver iodide, a chemical that encourages water crystal formation in clouds, according to Dan Breed, project scientist with the National Center for Atmospheric Research.
The silver iodide, a salt, is dissolved in acetone and ignited using propane, a process that essentially aerosolizes the chemical, spreading it up the sides of mountains and into the clouds. If the salt finds its way into cold clouds that have a high moisture content, the crystals encourage snowflakes to form.
“You have to have conditions where it would normally snow,” said Breed. The process only works well under certain conditions.
“The really big storms tend to be fairly efficient anyway,” he said. “In the past it’s been shown that seeding them doesn’t really help.”
Barry Lawrence, project manager for the Wyoming Water Development Commission, said the technology has been used in Utah and the Eden Valley Irrigation district west of the Wind River Range for decades.
“There’s a real interest right now in seeing what can be done,” he said. “The whole idea here is to increase snowpack. That is Wyoming’s biggest reservoir.”
The Wyoming Association of Conservation Districts made a formal application to the Wyoming Water Development Commission to look at the technology several years ago.
A $100,000 feasibility study in 2004-05 laid the blueprint for the research. The five-year pilot program would cost $8.8 million and involve research and evaluation components.
“It’s fraught with such peril,” Steve Thomas, spokesman for the Sierra Club, said of the plan. “Trying to manipulate precipitation is generally not a good idea. It has impacts that people are not anticipating.”
George Nickas, executive director of Wilderness Watch, said, “Weather modification, to the degree that it’s going to alter conditions in the wilderness, raises serious policy questions and serious legal questions.”
“The idea of attempting to manipulate a wilderness ecosystem in one of the few areas where we’ve decided, as a society, that we are not going to try to manipulate, flies in the face of the concept of wilderness,” Nickas continued. “We’re going to let nature reign in those places.”
Further, Nickas said that wringing the moisture out of clouds in the Winds could cause less moisture to fall out in the plains of Wyoming, depriving crops, animals and people with water.
Eric Winthers, soil and water program manager for the Bridger-Teton, said that although the silver iodide is likely not a cause for concern, pollution problems could arise. The increased snowfall might scrub particulates from the atmosphere, especially near the Upper Green River Valley where oil and gas drilling have increased particals in the air.
“Theoretically, if you’re producing more snow, you might produce more pollution in the form of acid precipitation,” he said. “We don’t know yet. We’d like to build into the study some data collection so that we can determine that down the road.”
Winthers said the Bridger-Teton is considering a categorical exclusion for the project, through the proximity to the Bridger Wilderness could trigger the need for an environmental impact statement.
“It’ll go out for scoping here pretty soon,” he said. Scoping seeks public comment on the scope of a proposed environmental study. “The [National Environmenntal Policy Act] process will probably start here in about two weeks and it will probably go out for public comment within the month.”