Columbia Basin Project, Banks Lake Dry Falls Dam & Main Canal Headworks, South end of Banks Lake, Northwest of Coulee City, Grand Coulee, Grant County, WA

Significance: The development potential of the Grand Coulee, a gorge carved out by the Columbia River before that waterway shifted its course, was a deciding factor in the Bureau of Reclamation's choice for the location of a massive irrigation project served by the waters of the Columbia River. The coulee's significance was underscored by the adoption of its name for the entire project. A dam at each end of the coulee has created an equalizing reservoir, filled by water pumped from the Columbia, that supplies the irrigation system. The North Dam is at the upper end of the reservoir, known as Banks Lake, while the Dry Falls Dam is at the south end, where the headworks controls the flow from the reservoir to the main channel of the irrigation system.
Survey number: HAER WA-139-F
Building/structure dates: 1946-1950 Initial Construction
Building/structure dates: 1956-1957 Subsequent Work
Building/structure dates: 1978 Subsequent Work