The Bonneville Power Administration is proposing construction of a new 500-kV transmission line to meet increasing demands for electricity along Washington and Oregon’s I-5 corridor. The line would meet growing local and regional energy demands and help bolster the BPA transmission system to accommodate energy deliveries, including wind power. The proposed line, known as the I-5 Corridor Reinforcement Project, would run between a new substation in the Castle Rock area of Washington and a new substation in Troutdale, Ore.

“BPA is committed to meeting local and regional power needs while ensuring a reliable and stable transmission system,” said Steve Wright, BPA administrator. “The region is growing and so is our need for energy, including green energy such as wind. This line would serve both of those needs.”

The transmission system in southwest Washington and northwest Oregon is heavily used and is approaching its capacity as power production and electricity consumption increase. This increased congestion combined with pending requests for firm transmission service and new patterns of electricity use make consideration of the system reinforcement necessary.

The high concentration of industrial, commercial and residential electricity use in Portland, Vancouver, Longview and surrounding suburban cities and towns is creating greater demand for electricity. BPA has taken innovative steps to keep pace with that growth without building new power lines, but the system is becoming increasingly stretched, and adequate electricity is essential to enabling economic growth and reliability.

“BPA and the region have used aggressive conservation measures and technical solutions to extend the use of the existing transmission system to meet growing energy needs,” said Brian Silverstein, BPA senior vice president of Transmission Services. “Now that we’ve used up that margin, it’s time to consider reinforcement activities.”

BPA is starting preparation of an environmental impact statement under the National Environmental Policy Act to aid in making a decision on whether to build a new line and to review potential environmental impacts associated with various possible route options. BPA will hold a series of public meetings this fall to take comments and answer questions about the project and the EIS process. The EIS process is expected to take about two and one-half years.

“We take our charge as responsible stewards of the environment very seriously,” said Greg Delwiche, BPA vice president for Environment, Fish and Wildlife. “An important part of that is interacting with the public to learn more about their transmission line siting concerns and to provide them with information to help them understand the rationale for the proposed line and the siting options.”