Columbia Basin Project were built at the north and south ends of Grand Coulee, the dry canyon south of Grand Coulee Dam, allowing the coulee to be filled with water pumped up from the Columbia River. The resulting reservoir, called Banks Lake, is about long. Banks Lake serves as the CBP's initial storage reservoir. Additional canals, siphons, and reservoirs were built south of Bank Lake, reaching over . Water is lifted from Lake Roosevelt to feed the massive network. The total amount of the Columbia flow that is diverted into the CBP at Grand Coulee varies a little from year to year, and
Grand Coulee Dam Clapp were pumpers, while many influential businessmen in Spokane associated with the Washington Water and Power Company (WWPC) were staunch ditchers. The pumpers argued that hydroelectricity from the dam could cover costs and claimed the ditchers sought to maintain a monopoly on electric power. The ditchers took several steps to ensure support for their proposals. In 1921, WWPC secured a preliminary permit to build a dam at Kettle Falls, about upstream from the Grand Coulee. If built, the Kettle Falls Dam would have lain in the path of the Grand Coulee Dam's reservoir, essentially blocking its construction. WWPC planted rumors