El Niño is bringing Southwest Colorado wet storms and even more reason to seed clouds than in a dry winter, some experts say.
“When there’s lots of liquid water coming through, then you have a storm to work. ... The seeding response is better. You get more bang for your buck,” said Joe Busto, a researcher with the Colorado Water Conservation Board.
To seed a cloud in Southwest Colorado, employees with Western Weather Consultants light generators that send vaporized silver iodide up to the base of clouds. The silver iodide forms an artificial ice nuclei and attracts supercooled water to form snowflakes.
In an ideal situation, the cloud would release excess water that would otherwise pass over the region, said Eric Hjermstad, co-owner and director of field operations for the company.
“It’s meant to add just a little bit more per storm,” Busto said.
A study in Wyoming conducted from 2005 to 2014 found cloud seeding can add 5 to 15 percent more precipitation.
During a dry storm or a dry year it’s harder to make a difference, he said.
Seeding during El Niño can help build snowpack to replenish aquifers and help fill reservoirs such as Lake Powell, Hjermstad said.
It’s an investment that is supported by regional water agencies and ski resorts that paid $237,900 this season, according to the Southwestern Water Conservation District. In this area, Western Weather operates about 36 generators from Pagosa Springs to Telluride, Hjermstad said.
This winter, the cloud-seeding supporters are looking to upgrade their efforts through better generators and potentially a radiometer that helps gauge the water and temperature of clouds before seeding, said Ken Curtis, engineer for the Dolores Water Conservancy District.
While he said there’s always skepticism around cloud seeding, the Wyoming study showed that cloud seeding can work if the silver iodide is delivered in the right place under the right conditions.
“We know it works, but you need to do best practices,” Curtis said.
Last week, the Southwest Basin Roundtable granted the group about $55,600 to hire a consultant to help select equipment and the right areas to place it.
The state will review and finalize the grant in the coming months, he said.
The strategic plan to upgrade equipment will likely take two years because there are 12 agencies and companies involved in funding.
Support for the program has been fairly stable, except for the city of Durango. The city has not contributed since the winter of 2013-14, said Laura Spann, with Southwestern Water Conservation District.
The City Council decided not to approve funding because of its questionable efficacy, said City Manager Ron LeBlanc.
The city also was the only municipality participating in the cloud-seeding program.
Councilor Dick White said he is uncertain about the impact of encouraging water to fall over certain basins and hurting regional neighbors such as the Navajo Nation.
“If you’re making more water fall in one place, it’s not falling someplace else,” he said.
To some degree Western Weather encourages snowfall over certain areas such as ski resorts, but it is dependent on what storm is moving into the region, Hjermstad said.
“It varies from storm to storm on what we are able to do,” he said.
mshinn@durangoherald.com
