The Dolores Water Conservancy District has partnered with the Idaho Power Co. and Colorado Water Conservation Board on the project.
“We are trying to take some leadership by upgrading the effectiveness of cloud seeding for southwest Colorado,” said Mike Preston, general manager for the Dolores Water Conservancy District.
Cloud seeders emit plumes of silver iodide into winter storm clouds to coax additional precipitation from clouds. There are about 30 cloud-seeding generators stretching in an arc from Telluride to Mancos to Pagosa Springs. Most of the units are 40-year-old designs and require an operator to turn them on and off when conditions warrant.
Idaho Power has developed a more efficient remote-controlled generator that can be placed in locations higher in the mountains and closer to the clouds they seed.
“The point is to get them out of the valleys and into the mountains,” said Brandal Glenn, a cloud-seeding engineer for Idaho Power.
The problem with valley generators is that they always suffer from inversions, he said, blocking the silver iodide from reaching the storm clouds.
“The remote generators allow you to get them up on the ridges so when the storm comes through they can be fired up remotely and inject the silver iodide directly into the cloud,” Glenn said.
The sweet spot for cloud seeding is stormy weather with temperatures between zero and 20 degrees Fahrenheit. The silver iodide bonds with water molecules and forces them to fall to the ground.
There’s a misconception that cloud seeding creates clouds out of clear blue sky.
“Cloud seeding targets the wet, icy, juicy clouds that have a lot of excess vapor not being converted to precipitation,” said Joe Busto, cloud-seeding manager for CWCB. He said a decade of scientific studies are showing that cloud seeding can increase storm precipitation between 1 and 5 percent.
Through a cost-share agreement with the state, DWCD purchased one of the units for $35,000. It was installed Aug. 30 in mountain terrain above 8,000 feet elevation north of Dolores.
“We’re bringing in state-of-the-art machines,” Busto said. “These allow us to get up close and personal with the mountains, and we have total control of the machines remotely. They have satellite communications so we can turn them on and off with a laptop or cell phone.”
DWCD has contracted with Western Weather Consultants to operate the area cloud-seeding program, including the new unit.
Five Western states, including Colorado, have earmarked $15 million to fund cloud seeding equipment in the Rocky Mountains over the next 10 years.