Bureau of Reclamation

In 1918, the U.S. Reclamation Service's director and chief engineer Arthur P. Davis proposed a dam of unprecedented height to control the devastating floods on the Colorado River, generate hydroelectric power, and store the river's ample waters for irrigation and other uses.

The massive Grand Coulee Dam, on the Columbia River, is the largest concrete structure in the U.S., the largest hydroelectric facility in the U.S., and the sixth-largest hydroelectric facility in the world. It provides irrigation for up to 1.1 million acres of agricultural lands and the hydroelectric complex maintains a generating capacity of 6.8 million kilowatts. It also serves as the primary flood control for the Columbia River basin (with a capacity of 5.18 million acre-feet of water) and provides recreational opportunities on the 150-mile-long Franklin D. Roosevelt Lake.