Lower Monumental Dam
View from the southwest
Lower Monumental Dam is located in the United States
Lower Monumental Dam
Location in the United States
Lower Monumental Dam is located in Washington (state)
Lower Monumental Dam
Location in Washington
CountryUnited States
LocationFranklin and Walla Walla counties, Washington
Coordinates46°33′47″N 118°32′20″W / 46.563°N 118.539°W / 46.563; -118.539
Construction beganJune 1961
Opening date1969 (1969)
Operator(s)U.S. Army
Corps of Engineers
Dam and spillways
Type of damConcrete gravity,
run-of-the-river
ImpoundsSnake River
Height100 feet (30 m)
Length3,791 feet (1,155 m)
Spillway typeService, gate-controlled
Reservoir
CreatesLake Herbert G. West
Total capacity432,000 acre⋅ft (0.53 km3)[1]
Surface area6,590 acres (26.7 km2)
Normal elevation540 ft (165 m)
Power Station
Turbines6 x 135-153 MW[2]
Installed capacity810 MW
932 MW (max)
Columbia River Basin
Columbia River Basin

Lower Monumental Lock and Dam is a hydroelectric, concrete, run-of-the-river dam in the northwest United States. Located on the lower Snake River in southeast Washington, it bridges Franklin and Walla Walla counties;[3][4] it is six miles (10 km) south of Kahlotus and 43 miles (70 km) north of Walla Walla.

Lower Monumental Dam with the lock in the center of the river (far side in photo), the power generation on the northwest side of the river, and spillway in the middle of the dam, between the powerhouse and the lock.

Construction began in June 1961, and the main structure and three generators were completed 55 years ago 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 (174 m) in length.

Built and operated by the U.S. Army Corps of Engineers, Lower Monumental Dam is part of the Columbia River Basin system of dams.

Behind the dam, Lake Herbert G. West is the reservoir; it extends 28 miles (45 km) east to the base of Little Goose Dam. Lake Sacajawea, formed from Ice Harbor Dam, runs 22 miles (35 km) southwest, downstream from the base of the dam.

Navigation lock
  • Single-lift
  • Width: 86 ft (26 m)
  • Length: 666 ft (203 m)

See also

References

  1. ↑ "The Four Lower Snake River Dams". Bluefish.org. Retrieved 17 July 2010.
  2. ↑ "Lower Monumental Dam". Washington.edu. Retrieved 17 July 2010.
  3. ↑ "Lower Monumental Dam". Lewiston Morning Tribune. (photo). March 19, 1964. p. 13.
  4. ↑ "The Columbia River System Inside Story" (PDF). BPA.gov. pp. 14–15. Archived from the original (PDF) on 27 May 2010. Retrieved 17 July 2010.
Wikimedia Commons has media related to Lower Monumental Dam.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.