Sign In
​Project Overview
BPA is proposing to build a 500-kilovolt (kV) lattice-steel-tower transmission line that would run from a new 500-kV substation near Castle Rock, Wash., to a new 500-kV substation near Troutdale, Ore. After initially identifying a large number of route segments, BPA combined those segments into four action alternatives (each with options): West, Central, East, and Crossover. The action alternatives and the No Action Alternative are analyzed in the project's environmental impact statement. The alternatives vary in length and include both existing and new rights-of-way.
BPA’s preferred alternative is the Central Alternative using Central Option 1. BPA accepted comments on the draft EIS from Nov. 13, 2012 through March 25, 2013. BPA responded to all comments received and documented them in Volume 3 (Volume 3A through 3H) of the final EIS. The comments and responses can also be searched online. For more information about how the action alternatives were developed, see Chapter 2 and Chapter 4 of the final EIS.
Purpose and need
A new transmission line would increase the long-term electrical capacity and transfer capability of BPA’s transmission capacity system in southwest Washington/northwest Oregon and allow BPA to provide for local load growth, maintain reliable power, and accommodate requests for long-term, firm transmission service. For more specific information about why the project is needed, see Chapter 1 of the final EIS.
See Electric Transmission Overview for general information about the transmission system. 
For specific design information about this project, including information about proposed towers, substations and other facilities, see Chapter 3 of the final EIS.