High-voltage power line to thread through southern Idaho

Federal officials released a plan for two high-voltage transmission lines in southwestern Idaho that avoid sage grouse habitat and private land but cross about 9 miles of conservation area for raptors.

The U.S. Bureau of Land Management released its final environmental impact statement Friday for the two segments of the Gateway West project proposed by Idaho Power and Rocky Mountain Power.

A final decision on the 2,200-page document would grant the power companies a right of way on public land to build the transmission lines and could be made by year's end. Margaret Oler, spokeswoman for Rocky Mountain Power, said the company is looking forward to final approval.

The segments are part of the 1,000-mile Gateway West transmission line project to deliver 1,500 megawatts from southern Wyoming through southern Idaho to points west, potentially tapping into Wyoming's wind energy.

Federal officials have already approved the rest of the project, but no work has started. If the two Idaho segments get a green light, construction of the entire power line will take place in phases between 2019 and 2024.

The Idaho portion has faced opposition from property owners and concerns about the environment where the lines cross the Morley Nelson Snake River Birds of Prey National Conservation Area.

A previous plan had the two routes going through mostly private land in the cities of Kuna and Melba and mostly public land in Owyhee County. Idaho Power and Rocky Mountain Power submitted revised applications for the two segments in 2014, and the government determined additional environmental analysis was needed.

The paths for the two high-voltage power lines look to avoid some of the previous problems.

"It's almost like trying to thread needles," Bureau of Land Management spokeswoman Heather Feeney said.

One of the power lines covers about 147 miles and the other, about 175 miles. They run parallel, about 250 feet apart, for roughly 103 miles.

"By locating the lines together, that's a step toward minimizing impacts as well," Feeney said.

The lines run parallel for about 9 miles through the bird conservation area. The federal plan includes details about work to offset possible harmful effects, including habitat restoration to benefit ground squirrels and other prey on which the area's eagles and hawks feed.

Officials say the transmission lines sidestep habitat for imperiled sage grouse, a bird found in 11 Western states.

The Gateway West project is one side of a giant triangle of transmission lines that Rocky Mountain Power says are necessary to meet future demands in the region and improve reliability. One part is finished, and the other segment is at an earlier stage in the environmental review process, Oler said.