Oahe Dam

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Oahe Powerhouse.jpg
Oahe powerhouse showing surge chambers and part of powerhouse, looking to north-west.
Official name Oahe Dam
Location 44°27′07″N 100°23′57″W / 44.45194°N 100.39917°W / 44.45194; -100.39917 Hughes / Stanley counties, South Dakota, USA
Construction began 1948
Opening date 1962
Construction cost $340 Million
Operator(s) United States Army Corps of Engineers
Dam and spillways
Impounds Missouri River
Height 245 feet (75 m)
Length 9,360 feet (2,850 m)
Dam volume 93,122,000 cubic yards (71,197,000 m3)
Spillways 8
Reservoir
Creates Lake Oahe
Total capacity 23,137,000 acre feet (28.539 km3)[1]
Surface area 374,000 acres (151,000 ha)[1] (max)
Power station
Commission date April 1962–June 1963[1]
Turbines 7x 112.29 MW
Installed capacity 786 MW
Annual generation 2,621 GWh[1]

The Oahe Dam is a large dam along the Missouri River, just north of Pierre, South Dakota in the United States. It creates Lake Oahe, the fourth largest artificial reservoir in the United States, which stretches 231 miles (372 km) up the course of the Missouri to Bismarck, North Dakota. The dam's powerplant provides electricity for much of the north-central United States. It is named for the Oahe Indian Mission established among the Lakota Sioux in 1874. The project provides flood control, electric power, irrigation, and navigation benefits, estimated by the Corps of Engineers at $150,000,000 per year.

Upper Lake Oahe (Reservoir), between Cannon Ball, North Dakota, and Pollock, South Dakota, as seen from space, October 1985. South is at the top of the photo.

History[edit]

Oahe Dam from the International Space Station

In September and October 1804, the Lewis and Clark Expedition passed through what is now Lake Oahe while exploring the Missouri River.

Oahe Dam was authorized by the Flood Control Act of 1944, and construction by the United States Army Corps of Engineers began in 1948. The earth main dam reached its full height in October, 1959. It was officially dedicated by President John F. Kennedy on August 17, 1962, the year in which it began generating power. The original project cost was $340,000,000.

Statistics[edit]

The lower Oahe Reservoir and Oahe Dam are near the bottom of this view; Lake Sharpe and Big Bend Dam are near the top, as seen from space, August, 1989. Pierre, South Dakota is near the bottom of the photo; Chamberlain, South Dakota is near the top. South-east is at the top.
  • Dam height: 245 feet (75 m)
  • Dam volume of earth fill: 92,000,000 cubic yards (70,000,000 m³)
  • Dam volume of concrete: 1,122,000 cubic yards (858,000 m³)
  • Spillway width: 456 feet (139 m)
  • Spillway crest elevation: 1,596.5 feet (486.6 m)
  • Lake maximum depth: 205 feet (62 m)
  • Plant discharge 56,000 cubic feet per second (1,600 m3/s)
  • Water speed through intake tunnels: 11 mph (5 m/s)
  • Intake tunnel length: 3,650 feet (average) (1110 m)
  • Number of turbines: 7, Francis type, 100 RPM
  • Power generated per turbine: 112.29 MW
  • reservoir storage capacity: 23,500,000 acre feet (29.0 km3).
  • States served with electricity: North Dakota, South Dakota, Nebraska, Minnesota and Montana
  • Number of recreation areas around lake: 51
  • Shore length: 2,250 miles (3,620 km)
  • Counties bordering lake: 14, including 4 in North Dakota (Burleigh, Emmons, Morton, Sioux), and 10 in South Dakota (Campbell, Corson, Dewey, Haakon, Hughes, Potter, Stanley, Sully, Walworth, and Ziebach)

Tours[edit]

Tours of the powerplant are given daily Memorial Day through Labor Day.

Native American displacement[edit]

As a result of the dam's construction the Cheyenne River Indian Reservation lost 150,000 acres (61,000 hectares) bringing it down to 2,850,000 acres (1,150,000 ha) today. Standing Rock Reservation lost 55,993 acres (22,660 ha) leaving it with 2,300,000 acres (930,000 ha). Much of the land was taken by eminent domain claims made by the Bureau of Reclamation. Over and above the land loss, most of the reservations' prime agricultural land was included in the loss. The loss of this land had a dramatic effect on the Indians who lived on the reservations. Most of the land was unable to be harvested (to allow the trees to be cut down for wood, etc.) before the land was flooded over with water.[2] One visitor to the reservations later asked why there were so few older Indians on the reservations, and was told that "the old people had died of heartache" after the construction of the dam and the loss of the reservations' land.[3]

Huff Archeological Site is a fortified Mandan village site on what is now the bank of Lake Oahe. It is designated a National Historic Landmark, but is endangered by erosion pressure from the lake.

2011 flooding[edit]

Oahe Dam release gates discharging floodwater at a record 160,000 cubic feet/second in June, 2011.

Excessive precipitation in the spring, along with melting snow from the Rocky Mountains forced the dam to open the release gates (not the spillway), releasing 110,000 cu ft/s (3,115 m3/s) in June with another 50,000 cu ft/s (1,416 m3/s) through the power plant totaling 160,000 cu ft/s (4,531 m3/s).[4] The previous release record was 53,900 cu ft/s (1,526 m3/s) in 1997.

See also[edit]

References[edit]

  1. ^ a b c d "Summary of Engineering Data – Missouri River Main Stem System". Missouri River Division. U.S. Army Corps of Engineers. August 2010. Retrieved 2012-08-17. 
  2. ^ Carrels, Peter (1999). Uphill Against Water. University of Nebraska Press. ISBN 0-8032-6397-X. 
  3. ^ "The Indians Are Getting Uppity". Ilze Choi. dickshovel.com. Retrieved April 5, 2009. 
  4. ^ Associated Press (June 7, 2011). "Oahe Dam Releases Water With Rumbling Force". Retrieved June 7, 2011. 

External links[edit]

Coordinates: 44°27′04″N 100°24′08″W / 44.45111°N 100.40222°W / 44.45111; -100.40222