BPA said that the new rate supports needed improvements to the region’s 31 federal dams and one nuclear power plant.

BPA administrator Steve Wright said that BPA needs to make careful investments to protect the substantial value of the Northwest power system.

"This rate strikes a balance that allows us to replace and refurbish aging equipment at the dams and Columbia Generating Station," Wright said.

According to the federal agency, the new wholesale rates would affect Northwest consumer-owned utilities such as public utility districts, tribal utilities, cooperatives, municipalities and federal entities.

BPA sells electricity to investor-owned utilities and direct-service industries under different rate structures.