The Bonneville Power Administration, Portland, Oregon, U.S., has decided to build the Kangley-Echo Lake 500-kV transmission line in King and Kittitas counties in Washington to accommodate electrical growth and reliability concerns in the Puget Sound area. The transmission line will parallel an existing transmission line through the Cedar River Municipal Watershed, east of Seattle.

The decision, signed July 21 by BPA Administrator Steve Wright, approves construction of this major project under the agency’s infrastructure expansion program to relieve congested paths across the Northwest.

“The new transmission line is critical to ensuring reliable electrical service in the Pacific Northwest. It supports the president’s National Energy Policy to balance America’s energy needs and will deliver reliable energy to homes and businesses. Bonneville has also assured that this new project will be built to the highest possible environmental standards,” Energy Secretary Spencer Abraham said.

BPA and the Seattle City Council reached agreement on construction of a five-mile portion of the line on land owned by the city of Seattle in the Cedar River Municipal Watershed in exchange for three parcels of land and mitigation funds that will be used to protect the watershed. Approvals were also obtained from the National Oceanic and Atmospheric Administration’s Fisheries and the U.S. Fish and Wildlife Service.

“Years of growth in the area have overtaxed the existing system. Crossing the watershed has the least environmental impact of any alternative we studied and we are using best environmental management practices to minimize potential risk to the natural habitat and drinking water in the area,” said Lou Driessen, project manager.

BPA will use special construction practices to protect the environment, including flying transmission towers and other equipment in and out of the area via helicopter, controlling erosion and monitoring water quality as well as planting native vegetation after construction is complete.

Construction of the line will begin immediately, with completion expected by the end of this year. The US$33 million project is financed by BPA and completely paid for through BPA sales of transmission services.

The Kangley-Echo Lake transmission line will begin near the community of Kangley, Washington, and connect with BPA’s existing Echo Lake Substation in the Maple Valley area. The nine-mile line will be built next to an existing 500-kV BPA transmission line and will require 47 new towers. The average tower height is about 135 feet.

During a two-year-long analysis of the project, BPA met with elected officials, government agencies, area tribes and local property owners and received more than 1600 comments.