The Crested Butte News Serving the Gunnison Valley since 1999
Not a “silver bullet” but does increase snowfall
Utah-based North American Weather Consultants is seeking authorization to continue high-altitude winter weather modification in Gunnison County. For eight winters now, the company has been using propane burners to “seed” winter clouds in Gunnison County and increase the accumulation of snow.
The Colorado Water and Conservation Board (CWCB) grants Weather Consultants its weather modification permit, and the previous five-year permit expired in April of this year. The company is seeking a 10-year renewal. The idea, according to Weather Consultants president Don Griffith, is to continue increasing the efficiency of existing snowstorms so they yield more snow—a good thing for ski areas and local reservoirs.
The company concentrates its efforts above 9,000 feet, where it burns a mixture of sodium and silver iodide to release tiny particles of silver iodide into the lower layers of clouds. That can cause water droplets to turn to snow at warmer temperatures than they otherwise would; long-term data suggests that cloud seeding boosts annual snowfall by 10 percent to 15 percent.
For Griffith, that makes it a worthwhile program but he cautions that it’s not the silver bullet some people expect. During a drought year like last winter, when Weather Consultants seeded 14 weather events, cloud seeding will not guarantee a normal snowpack.
“If you’re going to have 50 percent of snowfall naturally, and you get a 10 percent increase from cloud seeding, that would still result in a snowpack 55 percent of average,” Griffith explained. “There’s still a drought, it’s just going to be a little less dry than it would be naturally.”
To determine the impacts of cloud seeding, Weather Consultants measures snow water content on April 1. That data is then compared to historical averages and a control area where seeding does not occur to predict what snow water content would be without cloud seeding. On average, the company sees a 10 percent to 15 percent increase.
Last winter’s abnormal snowpack started melting in March, skewing this year’s data and suggesting that cloud seeding boosted snowfall by as much as 27 percent. “That threw things off, and in our minds, we didn’t trust that data,” Griffith said. The company opted not to include the 2011-2012 data in the long-term data.
As part of the permit renewal process, the CWCB will host a public hearing on Thursday, August 30 at 9 a.m. in the Board of County Commissioners’ hearing room at the county courthouse. Griffith doesn’t foresee any hurdles.
“It’s kind of an accepted thing at this stage. When we first started it was a new thing in that area so a number of people were attending the hearing, but when renewed last time there were only three or four people,” Griffith said.
Last fall, however, when Weather Consultants sought approximately $95,000 to fund the program there was some hesitation within the county to do so at historic levels—in spite of the fact that about half of that money comes from the CWCB in the form of matching funds.
In the face of its own funding shortages, the Upper Gunnison River Water Conservancy District (UGRWCD) questioned its typical contribution of $26,500. At the time, general manager Frank Kugel said, “It’s more a question of the science by a number of board members. I have tried to argue with mixed success that even if the calculations are off by a factor of 10 and you get $10 per acre foot water, that’s pretty darn cheap water.”
According to Griffith, conservative estimates indicate that cloud seeding provides water for around $1 per acre foot; the UGRWCD did continue its financial support. The county also contributed $10,000 and Mt. Crested Butte gave $3,000.
The CWCB is accepting public comment on the program’s permit renewal through Friday, September 7. Comments can be sent to the attention of Joe Busto at [email protected] or mailed to Weather Permitting Program, Colorado Water Conservation Board, 1313 Sherman St, Room 721, Denver, CO 80203.
