The Idaho Water Resource Board is considering increasing lake storage and seeding clouds to help boost water supplies in the Bear River Basin.

Overall goals are to provide more water for irrigation and other uses and to add to high-elevation snowpack, according to a board news release. Additional storage would be in Bear Lake. Cloud seeding could add to high-elevation snowpack in the river basin.

The Bear River — which supports irrigation, hydropower, native fish and recreation — originates in the Uinta Mountains of Utah, flows through a corner of southwestern Wyoming and makes a U-shaped course through a corner of southeastern Idaho before it flows back into Utah. The river drains into the Great Salt Lake, to which it is the largest tributary. The Great Salt Lake has seen low levels in recent years.

The river crosses state lines five times in its 350-mile course. A three-state compact governs water allocation. Idaho started an adjudication of water rights for its part of the basin in July 2021.

Bear Lake storage

The Bear River yields an average of about 800,000 acre-feet of water per year to the Great Salt Lake, while Bear Lake stores about 1.4 million at full pool, Matt Anders, technical services bureau chief for the Idaho Department of Water Resources, told the board. The board toured the Bear River Basin as part of its regular bi-monthly meeting in Soda Springs July 25-26.

The Idaho board filed for a Bear Lake water right to add storage. But the channel capacity of the Bear River would need to be increased from 1,500 cubic feet per second to 2,600 cfs to make that possible, Anders said.

Flood easements would need to be negotiated with landowners along the river in the Gentile Valley before channel capacity is increased, according to the release. Efforts to obtain the necessary easements are ongoing.

Cloud seeding

A National Center for Atmospheric Research study that the board funded in 2023 found opportunities for cloud seeding in the Bear River Basin by using ground generators and aircraft, according to the release.

And there is potential to share infrastructure with Utah for cloud seeding in the Upper Snake River region, said Kala Golden, cloud seeding program manager for IDWR.

Developing comprehensive ground and aircraft operations has been shown to be most effective at enhancing water supply with cloud seeding, but collecting real operational data and then assessing whether seeding supports long-term enhancement goals is needed, she said.

“There are a number of studies out there that indicate a well managed and scientifically based cloud seeding project can increase winter precipitation on average about 10%,” Golden said in the release. The council found good opportunities in the basin, “so it’s reasonable to assume we could see similar output from what NCAR has proposed.”

Cloud seeding “is an opportunity that we need to pursue,” said board member Marc Gibbs, who farms in the Grace, Idaho, area of the basin.