Third Power Plant

overhaul Project Power Plant Data Third Power Plant History

The Third Power Plant is the largest of the three powerhouses located at Grand Coulee Dam. Designed by famous architect, Marcel Breuer, the plant has a unique design reflecting a Brutalist architectural style. The powerplant was built from 1967 – 1975 with the six generating units installed over the following five years.

The plant contains three generating units rated at 600 MW and three units rated at 805MW, resulting in a total capacity of 4,215 MW. The average power generation at Grand Coulee is 21 billion kWH per year. The generation capacity of the Third Power Plant is about 2/3 of the total generation capacity at Grand Coulee Dam. When the Third Power Plant was completed and the last generating unit went into service in 1980, Grand Coulee was the largest hydropower plant in the world. Two of the generating units in the Third Power Plant can supply a city the size of Seattle with all its power needs for a year.

Related Links
Grand Coulee Dam
Grand Coulee Powerplant
Columbia Basin Project
Animation of Activities at Grand Coulee Dam's Third Power Plant

Lynne Brougher
Public Affairs Officer
(509) 633-9503

Last Updated: 1/23/19