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.
Parker DamState: CACountry: USAWebsite: http://www.asce.org/Project/Colorado-River-Aqueduct/Creator: Weymouth, Frank E.
Stretching 242 miles from the Colorado River on the California-Arizona border to its final holding reservoir near Riverside, California, the Colorado River Aqueduct consists of more than 90 miles of tunnels, nearly 55 miles of cut-and-cover conduit, almost 30 miles of siphons, and five pumping stations. Supplying approximately 1.2 million acre-feet of water a year - more than a billion gallons a day - it helped make possible the phenomenal growth of Los Angeles, San Diego, and surrounding Southern California areas in the second half of the 20th century.