LOGAN — Environmentalists and an energy company are squaring off over a proposal to build a $1 billion power project at Bear Lake.

Symbiotics, a Logan-based company, hopes to build the facility in Hook Canyon on the eastern shore of Bear Lake, which straddles the Utah-Idaho border.

The project would use electricity to pump water uphill from the lake at night into a reservoir and then use the flow of water from the reservoir during the day to generate 1,100 megawatts of peak-hour electricity daily.

The company would profit by buying electricity at the nighttime rate and then producing hydroelectric power during the day when demand and prices are higher, said Vincent A. Lamarra, Symbiotics chief executive officer.

"We are buying cheap power at night because it is plentiful relative to demand," Lamarra said.

But Jeff Salt of Salt Lake City, a member of the environmental group Great Salt Lake Keeper, thinks the project has risks.

"We are not certain yet what the impact will be, but we can start listing the risk factors such as water quality, aquatic wildlife and the local economy," Salt said. "We think that the raising and lowering of the lake all year long will prevent the lake from forming a contiguous ice sheet."

He said the lack of an ice sheet would harm the local economy during ice-fishing season. He said pollution and nutrients would be mixed by the new artificial current and thermal layers would be altered.

"The environmental impact when you look at the whole program from cradle to grave is going to be enormous," he said.

A member of the environmental group Bear Lake Watch worries the project could change the lake's level by as much as 3 inches a day, stirring sediments that could taint the lake's famous blue hue.

"To move that much water, for them (Symbiotics) saying it will not affect the lake is naive," said John Sphuler of Garden City.

Scott Tolentino, Bear Lake fisheries project biologist with the Utah Division of Wildlife Resources, has concerns about the project's impact on the four endemic fishes found in Bear Lake. Bear Lake white fish, Bonneville white fish, Bear Lake cisco and Bear Lake sculpin are found nowhere else.

"Bear Lake has very unique fish and very unique water quality, and there are a lot of risks there," he said.

But Lamarra contends the Hook Canyon project would benefit fish by providing breeding habitat.

"Our project is going to generate vast amounts of rock, and we're willing to use that substrate to enhance the fishery," he said.

The Hook Canyon project would use 14 reversible turbines that would both pump water up to the reservoir at night and generate electricity during the day.