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
Columbia River known as the Grand Coulee. After the floods, the river found its present course, and the Grand Coulee was left dry. The construction of the Grand Coulee Dam in the mid-20th century impounded the river, forming Lake Roosevelt, from which water was pumped into the dry coulee, forming the reservoir of Banks Lake. The river flows past The Gorge Amphitheatre, a prominent concert venue in the Northwest, then through Priest Rapids Dam, and then through the Hanford Nuclear Reservation. Entirely within the reservation is Hanford Reach, the only US stretch of the river that is completely free-flowing, unimpeded by dams