Construction of six new 500-kV overhead transmission lines at Grand Coulee Dam will begin in February 2012. The new lines will help ensure continued safe and reliable transmission of power between Grand Coulee Dam’s third power plant and the Bonneville Power Administration’s vast high-voltage power grid.

The decision to move forward follows BPA’s completion of the final environmental assessment for the Grand Coulee 500-kV transmission line replacement project and release of its Finding of No Significant Impact (FONSI). The U.S. Bureau of Reclamation, which operates Grand Coulee Dam – the largest hydroelectric facility in the U.S – also has released a FONSI on the project.

BPA assisted Reclamation with the design of the project and will be constructing it for Reclamation. BPA will fund the multi-million dollar project which also will bring dozens of construction jobs to the local economy for most of 2012.

“As we approach the 75th anniversary of the Federal Columbia River Power System, it is important that we make investments like this so we can continue to provide safe, reliable and low cost power to the Northwest for another 75 years,” said Mark Korsness, BPA project manager.

The six new 500-kV overhead transmission lines will replace six existing underground lines. The underground lines consist of aging, oil-filled cables between Grand Coulee’s third power plant and the 500-kV spreading yard. The new overhead lines will transfer power across the Columbia River and over the visitor center area, and then proceed uphill to connect to existing lines that transfer power from this area into the regional power grid.

The project will include the construction of new towers and access roads in the area. During construction, there will be temporary short-term closures of the park and highway, but no significant impact on the popular public laser show. Bids for the project will go out this month; a contractor will be selected in January.

“We have gone to great lengths to minimize the potential impacts of this project on the local community, while at the same time making the necessary improvements to a facility that has the capability to power six Seattles,” added Korsness.

Construction will continue through the winter of 2012, as weather permits. Both agencies will hold an open house before construction begins. At the meeting, there will be opportunities to learn more about the project and proposed construction schedule, as well as to discuss details with the construction contractors, Reclamation and BPA staff. The public will be notified about the date, time and location a few weeks prior to the meeting.

BPA, on behalf of Reclamation, prepared the environmental assessment to assist Reclamation in determining if the proposed action would cause significant impacts that would warrant preparing an environmental impact statement. In May 2011, BPA made the preliminary environmental assessment available for public review and comment. Comments were received and only minor revisions were made to the final environmental assessment.

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