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 interest in irrigation projects. The Bureau of Reclamation, desirous of a major project that would bolster its reputation, was focusing on the Boulder Canyon Project that resulted in the Hoover Dam. Reclamation was authorized to conduct a study in 1923, but the project's cost made federal officials reluctant. The Washington state proposals received little support from those further east, who feared the irrigation would result in more crops, depressing prices. With President Coolidge opposed to the project, bills to appropriate money for surveys of the Grand Coulee site failed. In 1925, Congress authorized a U.S. Army Corps of Engineers study