Opening date 1969 Height 30 m Length 1,155 m Phone +1 509-282-3218 | Impounds Snake River Opened 1969 Create Lake Herbert G. West Construction began June 1961 | |
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Location Franklin / Walla Walla counties, Washington, USA Operator(s) U.S. Army Corps of Engineers Type of dam Concrete gravity, run-of-the-river Spillway type Service, gate-controlled Address 5220 Devils Canyon Rd, Prescott, WA 99335, USA Similar Little Goose Dam, Ice Harbor Dam, Lower Granite Dam, Snake River, McNary Dam | ||
Preparing to replace lock gate at lower monumental dam
Lower Monumental Lock and Dam is a hydroelectric, concrete, run-of-the-river dam on the Snake River, and bridges Franklin County and Walla Walla County, in the state of Washington. The dam is located six miles (10 km) south of the town of Kahlotus, and 43 miles (69 km) north of the town of Walla Walla.
Contents
Construction began in June 1961. The main structure and three generators were completed in 1969, with an additional three generators finished in 1981. Generating capacity is 810 megawatts, with an overload capacity of 932 MW. The spillway has eight gates and is 572 feet (176 m) long.
Lower Monumental Dam is part of the Columbia River Basin system of dams.
Lake Herbert G. West, which extends 28 miles (45 km) east to the base of Little Goose Dam, is formed behind the dam. Lake Sacajawea, formed from Ice Harbor Dam, runs 35 miles (56 km) southwest, downstream from the base of the dam.