The U.S. Bureau of Land Management (BLM) has prepared a Final Supplemental Environmental Impact Statement (EIS) and Proposed Resource Management Plan (RMP)/Management Framework Plan (MFP) Amendments for the right of way (ROW) application for Segments 8 and 9 of the Gateway West 500-kV Transmission Line Project in Idaho.
With a planned notice in the Oct. 7 Federal Register, the BLM is announcing its availability and the opening of a protest period concerning the proposed RMP/MFP amendments.
PacifiCorp d/b/a Rocky Mountain Power and Idaho Power have submitted a ROW application to construct, operate, and maintain two 500-kV transmission lines on federal lands as part of the Gateway West project. The initial application proposed to construct transmission lines from the Windstar Substation near Glenrock, Wyoming, to the Hemingway Substation near Melba, Idaho, approximately 20 miles southwest of Boise, Idaho.
The original project was made up of 10 transmission line segments with a total length of approximately 1,000 miles and was analyzed in a Final EIS published in April 2013. The BLM issued a Record of Decision (ROD) in November 2013 that authorized routes on federal lands for Segments 1 through 7 and Segment 10 but deferred a decision for Segments 8 and 9.
In August 2014, the BLM received from the applicants a revised ROW application for Segments 8 and 9 and a revised Plan of Development (POD) for the project. The BLM determined that new information in the revised ROW application and POD, including revised proposed routes for Segments 8 and 9 of the transmission lines and several modified design features, required additional analysis of potential environmental effects to supplement the analysis presented in the 2013 Final EIS.
The notice of availability for the Draft Supplemental EIS was published on March 11, 2016, and the BLM accepted public comments on the range of alternatives, effects analysis and draft RMP/MFP amendments for 90 days, ending on June 9, 2016. During the public comment period, five open house-style public meetings were held in Hagerman, Boise, Kuna, Twin Falls and Murphy, Idaho.
Both the Draft and Final Supplemental EISs incorporate information contained in two reports developed in 2014 by the BLM Boise District Resource Advisory Council (RAC) subcommittee on Gateway West. One report identified and evaluated route options in the Boise District portions of Segments 8 and 9, and the second report examined potential mitigation and resource enhancement for impacts in the Morley Nelson Snake River Birds of Prey National Conservation Area (SRBOP). The BLM must determine whether to grant, grant with modifications, or deny the ROW application to use public lands for Segments 8 and 9 of the Gateway West project.
The Final Supplemental EIS analyzes in detail seven pairings of route alternatives for Segments 8 and 9 as Action Alternatives.
- Alternative 1 is the pair of revised proposed routes for Segments 8 and 9, as presented by the applicants
- Alternative 2 pairs the revised proposed route for Segment 8 and the Final EIS proposed route for Segment 9
- Alternative 3 is the revised proposed route for Segment 8 and a route designated 9K, which was developed as a result of scoping for the Draft Supplemental EIS
- Alternative 4 pairs the Final EIS proposed route for Segment 9 and a route designated as 8G, which was developed as a result of scoping for the Draft Supplemental EIS
- Alternative 5 pairs routes 8G and 9K
- Alternative 6 consists of the Final EIS proposed route for Segment 9 and a Draft Supplemental EIS route 8H
- Alternative 7 is routes 8H and 9K
The ROW width requested for all segments is 250 feet, except for Alternative 5, where a 500-foot ROW is required to accommodate two lines at the minimum separation distance. Portions of all route alternatives would cross the SRBOP. Both segments terminate at the Hemingway substation under all action alternatives. Segments are separated at distances of 250 feet to more than 30 miles, varying within routes and/or across alternatives.
The Final Supplement EIS identifies Alternative 5 as the preferred Alternative. This alignment minimizes crossing of the SRBOP to a total of 17.6 miles, 8.8 miles per segment in parallel, separated by 250 feet. The alternative avoids all GRSG Priority Habitat Management Areas, the Hagerman Fossil Beds National Monument, the historic Toana Freight Road, and Balanced Rock natural landmark in Twin Falls County.
Under the heading "Next Steps" on the project website, PacifiCorp said: "Both companies will work with the Bureau of Land Management to continue through the Supplemental Environmental Impact Statement process for segment 8 (Midpoint to Hemingway) and segment 9 (Cedar Hill to Hemingway), in support of a separate Record of Decision and right-of way grant for the remaining segments which is scheduled for October, 2016. The companies will evaluate next steps for segments 1 through 7 (Windstar to Populus, Populus to Midpoint and Populus to Cedar Hill) and segment 10 (Midpoint to Cedar Hill). The companies will consider impacts of the BLM’s deferred Record of Decision on segment 8 and segment 9 as well as updated customer and system needs."