Dry Falls Dam without compaction. Dry Falls Dam Dry Falls Dam is a rockfaced earthfill type dam in the U.S. state of Washington. Located in Grant County near Coulee City, it was built as part of the Bureau of Reclamation's Columbia Basin Project. Water from the Columbia River, impounded by Grand Coulee Dam, is pumped into Grand Coulee, a formerly dry canyon, through the short Feeder Canal. Grand Coulee's north end is sealed by North Dam and Dry Falls Dam stretches across the midsection of the Coulee. This allows the water pumped from the Columbia River to fill the upper Grand Coulee, creating
Grand Coulee Dam of electricity. Each generator is supplied with water by an individual penstock. The largest of these feed the Third Powerplant and are in diameter and can supply up to . The dam's power facilities originally had an installed capacity of 1,974 MW but expansions and upgrades have increased generation to 6,809 MW installed, 7,079 MW maximum. Grand Coulee Dam generates 21 TWh of electricity annually. This means the dam generates about 2,397 MW of power on average, which results in a total plant factor efficiency of 35%. In 2014, 20.24 TWh of electricity was generated. Grand Coulee Dam's spillway is