Sign In
I-5 Corridor Reinforcement
BPA will not build the I-5 Corridor Reinforcement Project
The Bonneville Power Administration will not build the I-5 Corridor Reinforcement Project, a proposed 80-mile, 500-kilovolt transmission line that would have stretched from Castle Rock, Washington, to Troutdale, Oregon.

BPA Administrator Elliot Mainzer announced his decision to not build the project on May 18, 2017. The decision concludes a comprehensive public process to determine whether building a new transmission line was the best solution to address an electrical reliability issue along a transmission corridor in southwestern Washington and northwestern Oregon. The decision to not build the transmission line reflects BPA’s commitment to implement new planning and management of its transmission system and commercial business practices.

We appreciate the time engaged stakeholders invested in the extensive review process, reading our material, attending meetings and providing comments as we took nearly nine years to complete a comprehensive review of the project and its potential impacts. We recognize the uncertainty this lengthy process created for people trying to make decisions about their properties and we are thankful for their patience and understanding. We could not make a decision of this magnitude without first acquiring the best possible information. BPA is confident the decision to not build the transmission line is the best decision for the region. 
Moving forward
After the release of the project’s final environmental impact statement in February of 2016, BPA began an extensive review of financial forecasts, planning assumptions and commercial practices. The results of those reviews were combined with findings of regional utilities and independent industry experts to address the underlying issue – managing congestion along the I-5 corridor while maintaining the potential for economic growth. Through this process, BPA determined it could meet its obligations to provide reliable, robust transmission service in a more innovative and sophisticated manner without building a new transmission line.

BPA will maintain grid reliability and continue supporting economic growth along the I-5 corridor by:

  • Identifying upgrades to existing transmission infrastructure
  • Updating business and commercial practices
  • Implementing a two-year pilot of “non-wires” projects to address congestion in the greater Portland-Vancouver area during peak periods of electricity use in summer