Online Open House: April 4 - June 9, 2016

An environmental impact statement (EIS) needs to have a range of reasonable alternatives that fully disclose the impacts of a proposed action and show the tradeoffs associated with different options.

The Draft Supplemental EIS analyzes in detail seven alternatives for segments 8 and 9 of the project, which would each span more than 125 miles between substations at Cedar Hill and Midpoint in south-central Idaho and the Hemingway substation in western Owyhee County. Each alternative includes one routing option for segment 8 and one routing option for segment 9, summarized in the table to the right. A No Action Alternative was analyzed in the 2013 Final EIS for the original Gateway West project and is incorporated by reference in the Draft Supplemental EIS.

Route alternatives

The table below shows the route pair that makes up each alternative. For maps of each alternative, click on the alternative name. Download table as PDF.

Segment 8 RouteSegment 9 Route
Alternative 1 Revised Proposed Route for segment 8
As presented by the Proponents
Revised Proposed Route for segment 9
As presented by the Proponents
Alternative 2
Co-Preferred Alternative
Revised Proposed Route for segment 8
As presented by the Proponents
Final EIS Proposed Route for segment 9
Alternative 3 Revised Proposed Route for segment 8
As presented by the Proponents
Draft Supplemental EIS route 9K
Developed as a result of scoping for the Draft Supplemental EIS
Alternative 4 Draft Supplemental EIS route 8G
Developed as a result of scoping for the Draft Supplemental EIS
Final EIS Proposed Route for segment 9
Alternative 5
Co-Preferred Alternative
Draft Supplemental EIS route 8G
Developed as a result of scoping for the Draft Supplemental EIS
Draft Supplemental EIS route 9K
Developed as a result of scoping for the Draft Supplemental EIS
Alternative 6 Draft Supplemental EIS route 8H
Developed as a result of scoping for the Draft Supplemental EIS
Final EIS Proposed Route for segment 9
Alternative 7 Draft Supplemental EIS route 8H
Developed as a result of scoping for the Draft Supplemental EIS
Draft Supplemental EIS route 9K
Developed as a result of scoping for the Draft Supplemental EIS
Portions of all route alternatives would cross the Morley Nelson Snake River Birds of Prey National Conservation Area (NCA).

Co-Preferred Alternatives: The agency has identified Alternative 2 and Alternative 5 as Co-Preferred Alternatives for purposes of public review and comment.

Agency Co-Preferred Alternatives

See Draft Supplemental EIS section 2.3.4 for details.

The BLM has identified two alternatives as Co-Preferred Alternatives: Alternative 2 and Alternative 5. The choice to have two preferred alternatives reflects the complexity of issues in the area of segments 8 and 9 and the BLM’s current thinking about the approaches to reaching a decision on authorizing segments 8 and 9. When selecting these Co-Preferred Alternatives, The BLM took into account last fall’s sage-grouse listing decisions and related resource management plan amendments, as well as mitigation considerations for the Morley Nelson Snake River Birds of Prey National Conservation Area (NCA).

Alternative 2 pairs the Revised Proposed route for segment 8 and the Final EIS Proposed Route for segment 9.

  • Segment 8 alignment avoids populated areas to the north of the NCA while minimizing disturbance in the NCA by paralleling an existing 500-kV line where the segment would cross the area.
  • Segment 9 alignment is the shortest analyzed in the Draft Supplemental EIS for this segment.

Alternative 5 pairs routes 8G and 9K, which were developed as a result of scoping for the Draft Supplemental EIS.

  • Route 8G alignment avoids crossing the northern portion of the NCA, the Hagerman Fossil Beds National Monument, and development near the town of Hagerman.
  • Route 9K alignment would involve the shortest crossing of the NCA (8.8 miles in a 500-foot wide ROW).
  • This alternative also avoids crossing the NCA and minimizes direct and indirect impacts to priority sage-grouse habitat.
  • This alternative makes most use of the Western Electricity Coordinating Council’s reduced mandatory minimum. separation distance for parallel transmission lines (250 feet).