Concerns are mounting over two proposed hydropower projects seven miles north of Idaho Falls.
On its surface, the proposed County Line Road Hydroelectric Project, flanking the Snake River on the Bonneville-Jefferson County line, is relatively low-key. It would use existing irrigation canals and produce about 2.5 megawatts of power.
But at public meetings and a site tour the week of July 6, residents, conservation groups and government agencies made it clear they are worried about the project’s impacts on a three-mile stretch of the Snake. They are especially concerned about how much water the irrigation districts would leave in the river during the winter, when flows are lowest.
The project is a joint effort between the Idaho and New Sweden irrigation districts. New Sweden has a canal on the west side of the river; Idaho on the east. Both want to build 35 by 35 foot powerhouses on opposite sides of the water to make the power.
The plan calls for rerouting as much as 2,000 cubic feet per second of water from the Snake into the canals, and through the hydropower turbines, before returning it to the river three miles downstream. In the growing season, sufficient water also would need to be sent through the canal for irrigation purposes. Canal banks would be built up by as much as five feet.
In April, the districts filed pre-application documents with the Federal Energy Regulatory Commission, which issues licenses for such projects. Three FERC officials were in town this week inspecting the site and holding meetings as the agency prepares to compile an environmental assessment of the project.
More than 30 attended a site tour July 8. They inspected the canals, headgates where additional water would be diverted from the Snake, and locations where powerhouses would be built.
Residents, canal company representatives, officials from several state and federal agencies, including the Bureau of Land Management and the Idaho Department of Fish and Game, and conservation group officials joined the tour.
That evening, close to 100 people — many of them neighbors of the proposed project — crammed into a Shilo Inn meeting room for a tense public scoping meeting.
“I wasn’t expecting this many people, but I’m glad you’re all here,” said FERC biologist Matt Cutlip, the lead federal official on the project.
The districts have said to make the projects profitable, they must operate the through the winter, when river flows are lowest, and canals usually would be dry. They have requested maintaining a minimum flow of 1,000 cubic feet per second in the Snake River through the season, generally between October and March.
Pulling roughly two-thirds of the water from the river during the winter has many worried about possible impacts to fish and wildlife — as well as views and home values. Studies the companies commissioned on the project said the project would actually be good for fish in the area, said Louis Thiel, a New Sweden board member.
Tom Bassista, an environmental biologist with Fish and Game, said his department is studying the project and compiling a letter it will send to FERC for its environmental assessment.
“Our primary concern is being able to craft a minimum bypass flow for the river that provides protection for fish and wildlife resources,” he said.
Less winter water might mean the river freezes over more frequently, which could harm fish and wildlife, Bassista said.
“We know the irrigation districts require so much water to produce energy and rivers typically have a biological threshold for what they need, so we’re trying to balance those two,” he said.
Bassista said he wasn’t yet sure if 1,000 cfs would be sufficient.
At the July 8 meeting, Nick Josten, an Idaho Falls consultant coordinating the FERC application process for the districts, said requiring a higher minimum flow, such as 2,000 cfs, would probably kill the project.
Bill Smith, a resident of the Bear Island neighborhood along the river, said he is concerned about buildup of loose “frazil” ice in the winter. The ice could build up around the powerhouses, he said, causing a clog and sending water over the banks.
Smith recalled a similar ice-induced flooding incident on the same area of the Snake River in the 1980s, which inundated two homes.
“Every property adjacent to the canals is going to be at risk of being flooded,” he said.
Josten said the canal companies would have a bypass mechanism in place to ensure water could always continue to flow past the powerhouses, and not back up into the canals.
Concerns also have been voiced about the appearance of the river at such low flows. Many homes in the area have uninterrupted views, with lawns leading to the water’s edge.
Amy Lientz, an Idaho National Laboratory employee, lives with her husband in one of those waterfront homes, which has a dock.
She said her primary concern about the project is about keeping a healthy river habitat. The area around her residence is home to a variety of animals, including Yellowstone cutthroat trout, otters, eagles and trumpeter swans. She’s also concerned about the impact on recreation, including effects on fly fishing, and the ability to operate a boat without much water.
The canal companies have proposed building a boat ramp, but residents said July 8 another boat ramp in the area wouldn’t be of much use in times of the year when water levels were so low.
Thiel said the two companies have been working on the project for about eight years. It could be several years more before the project has final approval. If it’s built, the river is “definitely going to be different than what people are used to,” Lientz said.