From todays paper:
Cloud seeding efforts renewed
Denver wants twice as many machines to boost watersheds
By Jason Blevins
Denver Post Business Writer
Tuesday, August 06, 2002 - Denver is planning to more than double the number of cloud-seeding machines at work this winter in Colorado's mountains.
The Denver Water Board on Wednesday will weigh a recommendation from Denver Water manager Chips Barry to begin using ground-based generators to seed passing clouds to create more snow in the mountains as potential relief from one of the state's worst droughts.
The proposed $700,000 plan calls for a private company to install 41 additional generators in five counties that are home to Denver watersheds. There are 34 generators operating near Vail and in the San Juan Mountains near Lizard Head Pass.
Barry said he has contacted between 20 and 30 water districts, municipalities and ski areas in the counties, hoping to sign up contributors.
"They are overwhelmingly supportive," Barry said. "This is the part that fascinates me. Where else in life do you get to say to somebody: "I'd like you to participate and help me out, but if you don't help, you'll get all the benefits.' It adds a very interesting moral, philosophical and political twist to this."
Barry's proposal calls for enlisting Durango-based Western Weather Consultants, which runs existing cloud-seeding generators around the state, to install and maintain the new machines. They would be placed on private land in Summit, Grand, Park, Gilpin and Jefferson counties, all of which are home to Denver watersheds in the Fraser, Blue and South Platte river basins.
The proposed Denver Water contract would run from November through March.
Larry Hjermstad, owner of Western Weather, would watch approaching weather patterns and call landowners to have them turn the generators on. The machines fill passing clouds with silver iodide crystals that bind to water particles, pulling them earthward.
At its best, the machines can cull an extra 10 percent to 20 percent of precipitation from storm clouds, Hjermstad said.
"But we have to have wet weather," he said, noting that for cloud seeding to work, there need to be precipitation-heavy clouds overhead.
Cloud seeding is not new in Colorado, although it has been little used in the past 17 years. Denver water watchers and all but one of the state's ski areas quit cloud seeding in 1985, when memories of the mid-'70s drought were well faded.
From the late-1970s through 1985, cloud seeding was common at Colorado's ski areas. Aspen, Vail, Beaver Creek, Telluride and Purgatory all enlisted Hjermstad's cloud-seeding generators. So did the state of Colorado.
"We ran a huge program for the state in the late '70s and early '80s," Hjermstad said. "The origin of that was essentially the drought of 1976-77. The state was very interested in getting its water supplies up to normal, and ski areas also became avid participants."
By 1985, reservoirs were brimming, and ski areas had developed snowmaking systems to augment fickle snowfall. Hjermstad's business wilted. Only Vail and Beaver Creek have remained on-board, using cloud seeding every season for the past two decades.
"It does positively influence the amount of snow we receive," said Bill Jensen, head of operations at Vail Mountain.
Vail and Beaver Creek split the $134,000 annual cost to run 14 of Hjermstad's machines. Jensen said a recent analysis of the past 16 years of cloud seeding in Vail showed a 15 percent increase in inches of snowfall. That increase comes while the machines are running. Denver's benefit comes six months later in reservoirs miles away.
It's a gamble that's worth the risk, Barry said.
"I think it is likely, but not guaranteed, we will get more snow," he said. "The situation with the drought is so severe, I am ready to take that risk."
Good call, said John Porter, manager of the bone-dry Dolores Water Conservancy District in Cortez, which used Hjermstad's cloud-seeding generators this year but had no clouds to seed.
"You need the right kind of storms, but the payoff is worth it," Porter said. "Vail boosted their snowfall by 15 percent. Take half of that. Just half. That is by far the cheapest water you can come up with."