In what looks to be the second consecutive below-average water year for Northern Nevada, a program that modifies cloud structures in the Tahoe area to increase the odds of precipitation is on hold due to lack of funding.
After more than four decades of nearly continuous operation, no ski resorts or state or local agencies rallied behind Desert Research Institute’s cloud seeding program, likely due to financial concerns agencies are facing during the COVID-19 pandemic, said DRI Associate Research Scientist Frank McDonough.
Cloud seeding is a method of altering the amount of precipitation formed in clouds by adding substances such as silver iodide to increase rain or snowfall. Scientists use aircraft or ground generators strategically located in the mountains to introduce the silver iodide.
Other cloud seeding programs throughout the West overseen by DRI, including programs in southern Nevada and the Colorado River Basin, remain funded. But McDonough had a hard time convincing Tahoe-area agencies to help fund the Tahoe Basin project, which can generate enough water for about 40,000 Reno households.
“This was a really weird year. The ski areas were interested but they had so much uncertainty. When we were trying to get the project funded initially this year, they didn’t even know if they were going to open. The other potential sponsors also had a lot of uncertainty,” McDonough said.
Revenue uncertainty halted the program
The Tahoe-Truckee Basin Cloud Seeding Project relies on ground generators, most of which were installed in the 1980’s to early 2000’s with state funding, McDonough said.
There are eight generators that target the Tahoe Basin area. Costs to operate the generators for a season run around $150,000 to $200,000, and DRI relies on state and local agencies to fund the seeding.
The state funded the Tahoe-Truckee Basin Cloud Seeding Project from 1977 to 2009. Since then, agencies including the Truckee River Fund, Truckee Meadows Water Authority, Western Regional Water Commission, Mt. Rose Ski Tahoe and the Pennington Foundation have funded the project.
But after decades of near-continuous funding and operations, “This winter, there wasn’t a sponsor for the project,” McDonough said.
Revenue uncertainty due to COVID played a role in funding, said John Enloe, natural resources director for Truckee Meadows Water Authority.
“With COVID and everything else, it kind of shut everything down,” Enloe said. “It would be great to spread the costs around to everyone that’s benefitting.”
Heading into the winter, McDonough reached out to various Tahoe ski resorts that benefit from the enhanced precipitation, but the resorts opted out.
“This year they asked, but with it being a COVID year, we weren’t able to,” said Mt Rose Ski Tahoe Marketing Director Mike Pierce. He said going forward, the resort will continue to consider funding the project. “It’s on behalf of snow and moisture, which benefits our resort and our region.”
No other ski resorts have helped fund the Tahoe cloud seeding program.
McDonough said while understands financial concerns because of the pandemic, he’s baffled that resorts that will pay for snowmaking – which can run up bills of millions of dollars, he said – but are hesitant to fund cloud seeding.
“All that (snowmaking) does is pull water out of a pond and pipes it up a hill and blasts it onto the mountain. It doesn’t create anything new. What we do is put new snow on the ground,” he said. “I think they need to be convinced what cloud seeding can do for them. And that’s on us to show them that what we’re doing is a benefit to them.”
Generating water for up to 40,000 Reno households
DRI has been involved in cloud seeding since the early 1960’s, roughly 20 years after it was developed. In addition to enhancing precipitation, it can alter lighting and thunderstorms, hurricanes and fog.
DRI is instrumental in cloud seeding operations throughout the country, including projects on the Colorado River Basin and in Southern Nevada.
Over the past few decades, the target of DRI’s Tahoe-Truckee Basin Cloud Seeding Project was to get more water into the Tahoe Basin and the Truckee River, McDonough said. The project can provide enhanced precipitation to about 200 square miles of the Tahoe Basin.
Cloud seeding can increase seasonal snowpack by about 10 to 15 percent. In years where the program operates in the Tahoe Basin, enough water is generated to benefit about 40,000 Reno-area households, according to McDonough.
Extensive testing at the Colorado State University Cloud Chamber shows that 1 gram of silver iodide can produce enough ice crystals to produce 1 acre-foot of water, McDonough said. Long-term analysis of the Tahoe-Basin project shows one additional inch of snowfall for every 10 inches that fall during seedable hours. On an average year, the generators run for about 200 hours, creating about 21,000 acre-feet of water, he said.
And in Nevada, the driest state in the nation, getting all the moisture possible is important, especially in a below-average year. As of Feb. 23, the Lake Tahoe Basin was only at 62 percent of average monthly precipitation, while the Truckee River Basin was at 61 percent, according to the Natural Resources Conservation Service Nevada.
“Putting water in the river keeps the river cooler, which helps fisheries,” McDonough said. “The trees are happier. You get a couple extra weeks of snow on the ground. It keeps the streams running a little longer. It’s important in a dry year.”
How it works
During the West Coast’s rainy season, dust from as far away as the Gobi Desert in Asia will drift across the Pacific Ocean into the Sierra. When clouds over the Sierra form, moisture clings to those dust particles to form ice crystals, McDonough said. “And those ice crystals are a large part of snowflakes that fall to the ground.”
Cloud seeding introduces additional special dust particles made of silver iodide molecules allowing additional ice crystals to form, grow and fall to the ground as additional snow. The silver iodide has a similar molecular structure to ice and encourages snow to form.
“If you can get this silver iodide into the clouds where these dust particles are, you can get them to freeze and then they grow, and you can create extra snow,” McDonough said. “We are trying to get clouds that aren’t as efficient as they could be to produce snow.”
Introducing one gram of silver iodide – about a tablespoon or two – to passing clouds can help induce clouds to make one-acre foot of water. That’s enough for two Reno households for a year.
Effectively cloud seeding hinges on a few different factors. Clouds must be below the tops of mountain peaks, temperatures must be within a specific range and wind must be blowing in the correct direction.
McDonough said no funding has come in yet to cloud seed the Tahoe Basin for the 2021-2022 water year, but that projects don’t usually come together until the summer.
“I’m optimistic,” he said. “We believe it’s an important project to help. In dry years, water is super valuable. Even if you can’t put a ton down, it’s still super valuable. What usually brings it back is a dry winter – once water gets a little more scarce, people become more interested.”
Amy Alonzo covers the outdoors, recreation and environment for Nevada and Lake Tahoe. Reach her at firstname.lastname@example.org or (775) 741-8588. Here’s how you can support ongoing coverage and local journalism.