Drought raises curiosity about cloud seeding in Oregon

June 6, 2022
Drought raises curiosity about cloud seeding in Oregon

MADRAS — Another year of exceptional drought in Central Oregon is raising questions about whether cloud seeding can boost the region’s water supplies by increasing snowfall that feeds into streams and reservoirs.Finding out the answer, however, could be difficult and expensive, with no guarantee it would make a meaningful difference, some experts say. Others say it could cause more precipitation to fall from storms, bolstering the overall water supply.Cloud seeding is a form of weather modification in which certain chemical compounds — most commonly silver iodide — are released into the atmosphere by either aircraft or ground-based generators.

The particles provide a “seed” for moisture in the air to condense and fall to the ground as rain or snow. Mike Britton, executive manager of the North Unit Irrigation District in Madras, said he is familiar with cloud seeding programs in Idaho and California, and believes it could hold promise for the parched Deschutes and Crooked river basins. “We’ve been in about a 10-year dry cycle, with the last two years being really bad,” Britton said. “It’s driven me looking into this even more, given where things are today.” Conditions are dire for patrons of the North Unit. The district, which provides irrigation water for 59,000 acres of farmland in Jefferson County, set its 2022 water allotment for 0.45 acre-feet per acre, less than one-quarter of the normal need. “You can’t grow a whole bunch of stuff on less than half an acre-foot of water, unfortunately,” Britton said.

If it can be done practically, Britton said cloud seeding might help to deliver more snow in parts of the Cascade Range that eventually melts and feeds the river system, benefiting farms, wildlife and hydroelectric generation. But first, a climatology study is required to determine if the region can actually support cloud seeding. Such a study could cost several hundred thousand dollars. Britton said he is considering approaching state lawmakers about funding. “If it’s going to get done, it needs to be done sooner rather than later,” he said.

Study required

Larry O’Neill, Oregon state climatologist, said cloud seeding has been tried in the state before. In the late 1970s, Portland General Electric experimented with cloud seeding to enhance runoff for hydropower. The project was dropped after PGE estimated it increased average snowfall by just 10%, which O’Neill said was not statistically significant. Residents also raised concerns about whether cloud seeding changed the intensity of snowstorms, making roads more dangerous.

Neither the Oregon Climate Service nor the Oregon Climate Change Research Institute are currently involved in exploring cloud seeding locally, O’Neill said.“I don’t know of any immediate environmental conditions in the rest of Oregon that would necessarily preclude such efforts here,” he said. “However, the water supply benefits are fairly small and wouldn’t substantively change the severity of the droughts we’ve been experiencing, unfortunately.”

How to do it

The nonprofit Desert Research Institute has run a wintertime cloud seeding program since the 1960s, and assists with operating projects in California, Nevada and Colorado. Frank McDonough, the program’s director, said to develop an effective cloud seeding project, they need to study weather models to determine when, where and how often clouds may be ripe for seeding — that is, whenever there are enough water droplets in subfreezing clouds to initiate precipitation.

While McDonough said nobody has ever seriously talked with the institute about cloud seeding in the Oregon Cascades, his gut instinct is the storms are “probably seedable.”“The real challenge would be where the equipment could be put, and who wants the water,” he said. Such a project would need to be sponsored by the state or public agency, such as an irrigation district. Oregon law already has a licensing system in place for weather modification through the state Department of Agriculture. Applications can be filed for a $100 fee.

Idaho’s experience

In Idaho, the utility Idaho Power began cloud seeding operations in 2003. The goal, similar to that of PGE, was to augment runoff for hydroelectric generation. Since then, the program has expanded from the Payette Basin to the Upper Snake and Wood river basins, using 57 ground-mounted generators and three aircraft to disperse silver iodide during the winter. Shaun Parkinson, cloud seeding and water resources leader for Idaho Power, said results are proving to be worth the effort.

Depending on the watershed, he said cloud seeding has increased winter precipitation 5-15%, resulting in an additional 1 million acre-feet per year of unregulated runoff.For comparison, 1 million acre-feet of water is equal to five times the capacity of Wickiup Reservoir. What started as a smaller pilot project gained traction when the state of Idaho became interested in whether cloud seeding could help watersheds become more drought-resilient by recharging aquifers and bolstering reservoir carryover. Today, Parkinson said Idaho Power, the state of Idaho and local irrigation districts all share in the cost of the program, which is about $3.5 million per year.” You can wind up with a lot of common interest in cloud seeding,” he said. “It’s hard to find people who oppose having more water in water-stressed environments.” That being said, Parkinson emphasized that cloud seeding is not a “drought solution,” but rather a long-term water management tool.

It does not create new snowstorms, but may increase the amount of snow that falls from existing storms. ”You’re just increasing what’s happening naturally,” he said. “If you have a 10% increase over nothing, you still have nothing.” McDonough, with the Desert Research Institute, echoed that sentiment. He added that cloud seeding is not a substitute for water efficiency, but over time it can give a little extra snow and a little extra runoff. “You definitely want to do the study and understand the storms, and the potential to seed them,” he said. “Then you can say, here’s what a program could theoretically look like.”-George Plaven

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