Grand Coulee Dam via the Pump-Generating Plant's diameter pipes from Lake Roosevelt to a feeder canal. From the feeder canal, the water is transferred to Banks Lake which has an active storage of . The plant's twelve 65,000–70,000 horsepower pumps can transfer up to to the lake. Currently, the Columbia Basin Project irrigates with a potential for . Over 60 different crops are grown within the project and distributed throughout the United States. Grand Coulee Dam supports four different power houses containing 33 hydroelectric generators. The original Left and Right Powerhouses contain 18 main generators and the Left has an additional three service
Grand Coulee Dam the year. For example, while the dam may generate at nameplate-capacity in the spring, decreased river flow in the fall means less power can be generated the rest of the year, resulting in a lower capacity factor. The proposal to build the dam was the focus of a bitter debate during the 1920s between two groups. One group wanted to irrigate the ancient Grand Coulee with a gravity canal while the other pursued a high dam and pumping scheme. The dam supporters won in 1933, but for fiscal reasons the initial design was for a "low dam" tall which would