Bonneville Power Administration (BPA) is proposing to construct a new 18-mile-long 115-kilovolt (kV) transmission line between BPA’s existing Badger Canyon Substation in Benton County, Washington and BPA’s existing Ashe-Marion 500-kV transmission line to the west.

The Tri-Cities area is growing, and the increasing demand for power is adding to the area’s existing transmission system constraints. The primary goals of this project are to improve long-term electric reliability, improve short-term operational flexibility and address system maintenance needs. This project would also allow BPA to increase the amount of electricity it can deliver into the area. This project could also help BPA to incorporate future generation and line/load interconnection projects in the region.

This is one of four projects BPA is proposing in the area, collectively referred to as the Tri-Cities Reinforcement program. When complete, the program would increase BPA’s transmission capacity in the area by 66 percent. This work would also update BPA’s current Tri-Cities infrastructure by reinforcing substations and transmission lines.

The transmission lines that bring power into the Tri-Cities are at risk of becoming overloaded during periods of high electricity use, which potentially could lead to unplanned power interruptions or blackouts in the absence of other measures. Overloading could occur during summer irrigation season, during summer when air conditioning use spikes, and in winter when heating is peaking. In addition, the possibility of an unplanned power interruption increases when BPA takes one of the lines currently serving the Tri-Cities area out of service for regular maintenance. During a planned outage, the other lines feeding into the area are at increased risk of becoming overloaded, which could also lead to loss of load events. Unplanned outages can also be caused by such things as equipment failure, a public safety power shutoff that may be necessary to ensure safety and reliability during wildfire season, lightning, or a transmission pole struck by a vehicle. This new transmission line and substation would help relieve stress on the system and substantially reduce the potential for unplanned outages because it would provide an alternative path for electricity to flow if another line in the region becomes inoperable.

BPA is proposing to build a new Webber Canyon Substation next to the existing Ashe-Marion 500-kV line and connect the new substation to BPA’s existing Badger Canyon Substation with a new 18-mile-long 115-kV transmission line. A small portion of the new line would be built with steel monopoles in an existing transmission corridor near Badger Canyon Substation. The rest of the new line would be built using wood pole structures. Two proposed route alternatives are under consideration. Fiber optic cable would be added to the new line, as well as other existing transmission lines ithe area, to improve operational communication and control. Badger Canyon Substation would be reconfigured and upgraded to incorporate the new transmission line.


BPA previously held an informal public meeting in December 2022. Input from that meeting helped guide the proposed project design. To understand the potential environmental impacts of this proposal, BPA may prepare an environmental assessment (EA) following the procedures of the National Environmental Policy Act (NEPA). The EA would analyze the substation and transmission line build, including the two proposed route alternatives, as well as a no-action alternative in which no construction actions would be taken. The EA would also describe anticipated impacts to natural and human resources and would identify mitigation measures to help avoid or minimize impacts. During this process, BPA will work with landowners, tribes, federal, state and local agencies, and interest groups.

The proposed schedule for the environmental review is as follows:

Scoping comment period - October 06 to November 20, 2023

Public scoping meetings - October 17 and 18, 2023

EA determination - Spring, 2024

Draft EA available for public comment (if warranted) - Summer, 2024

Final EA (if warranted) - Winter, 2024/2025

Finding of No Significant Impact (if warranted) - Fall, 2024

If decision to build, construction start - Spring, 2025  


BPA has concluded scoping and the comment period closed on November 20, 2023. BPA is now considering comments to help determine if an Environmental Assessment is warranted and the issues that should be addressed in the environmental review. 


For project information, contact:
Amanda Williams           
Transmission Project Manager

Bonneville Power Administration – TEPL-TPP-1
PO Box 3621
Portland, Oregon 97208-3621
Toll-free: 800-622-4519
Direct line: 360-619-6634

Rasha Kroonen
Substation Project Manager
Bonneville Power Administration - TEPS-TPP-1
PO Box 3621
Portland, Oregon 97208-3621
Toll-free:  800-622-4519
Direct line: 360-619-6634

For environmental information, contact:
Douglas Corkran                              
Environmental Protection Specialist
Bonneville Power Administration – ECT-4
PO Box 3621
Portland, Oregon 97208-3621
Toll-free: 800-622-4519
Direct line: 503-230-7646


Scoping comments received
Public Letter (10/06/2023)
New Transmission Line Detail Map (10/06/2023)
Project Overview Map (10/06/2023)
Comment Form (10/06/2023)