With Wyoming Gov. Mark Gordon’s Tuesday signing of the 2021 Water Omnibus Bill, funds will flow to area irrigation projects, cloud seeding efforts and $24.2 million worth of other projects around the state.

Projects for improvements of the Shoshone and Sidon canals and Northwest Rural Water were funded for a combined total of close to $2.3 million. The bill also included $943,000 for airborne cloud seeding operations that could bring more snow to the Wind River, Sierra Madre and Medicine Bow mountain ranges, eventually sending more water downstream to parched areas in southern Wyoming and neighboring states.

Wintertime mountain cloud systems have been seeded to increase snowpack and water supplies for decades, ever since the discovery that ice crystals could be generated by injecting silver iodide (AgI) into a cloud of supercooled liquid.

During this process, termed glaciogenic seeding, aerosols of the chemical are introduced into a supercooled liquid cloud to form ice crystals, which become heavy enough to fall to the ground as snow.

Despite being practiced for years, critics have doubted the cost benefits of the process due to the difficulty of quantifying results. But a 2018 study in Idaho, recently published in the Proceedings of the National Academy of Sciences, showed positive results from combining radar technology and precipitation gauges to measure snowfall generated from seeding winter mountain cloud systems.

For cases presented, precipitation gauges measured increases between 0.05 and 0.3 mm as precipitation generated by cloud seeding passed over the instruments. At the top end of the measurement, the amount equaled about 0.1 inches of additional snow.

It doesn’t sound like a lot, but the total amount of water generated in the study ranged equaled about 100-acre-feet in 20 minutes of cloud seeding. To help visualize an acre-foot of water, an Olympic-size swimming pool is about 2-acre-feet of water.

“This is a revelation. We can definitely say that cloud seeding enhances snowfall under the right conditions,” said Sarah Tessendorf, a scientist at the National Center for Atmospheric Research in Boulder and co-author of the research conducted by a team from the University of Colorado Boulder and University of Wyoming.

The net gain of snowpack is about 10%, said State Rep. Dan Laursen, R-Powell, who chairs the Legislature’s Select Water Committee and is also a hydrographer in the State Engineer’s Office. Hydrography is the branch of applied sciences which deals with the measurement and description of the physical features of bodies of water.

“I think it’s an important project that we keep going,” Laursen said. “You know, people don’t look at it, or think about it, but it could help the forests in their fire seasons, just by getting some more moisture in there.”

Laursen doesn’t envision cloud seeding being utilized in Park County, but said it’s often employed in other states as well as by ski lodges in resort areas like Vail, Colorado.

The plan still has its critics, though.

“They have positive results, but they’re not great,” said Rep. Mike Greear, R-Worland. “Now we’re just going to go ahead and jump in and take over some different basins.”

Greear said he would have preferred more analysis on the economic benefits of cloud seeding, The Associated Press reported. He’s also concerned about starting new programs that will draw down the state fund for water projects.