Statistics (Cubic Feet per Second = CFS; Mean Sea Level = MSL; Kilowatts = Kw; Revolutions per Minute = RPM)
Significant Dates:
- Operating Since: 1964
- Construction Start: 1959
- Closure: July 24, 1963
- Reservoir filling initiated: November 1963
- Reservoir first reached minimum operating pool: March 25, 1964
- Initial Power Generation – First and Last Units: October 1964 – July 1966
Powerplant
- Number of turbines: 8 Fixed blade, 81.8 rpm
- Max power generation capability: 494,320 Kw
Size
- Ranking: 54th largest reservoir in the United States
- Length of Dam: 10,570 feet (including spillway)
- Damming Height: 78 feet (low water to maximum operating pool)
- Maximum Height: 95 feet
- Maximum width at base: 1,200 feet (total)
- Maximum width at base: 700 feet (without berms)
- Elevation at crest: 1,423 feet msl
Construction
- Abutment formations (under dam & embankment): Pierre shale & Niobrara chalk
- Type of Fill: Rolled-earth shale fill & chalk fill
- Amount of Fill: 17,000,000 cubic yards of fill
- Amount of Concrete: 540,000 cubic yards
Spillway
- Location: Left bank - adjacent
- Width: 376 feet gated
- Number of gates: 8
- Dimension of gates: 40-foot x 38-foot tainter gates
- Design discharge capacity: 390,000 cfs at 1,433.6 feet msl pool elevation
- Discharge capacity at maximum operating pool: 270,000 cfs at 1,423 feet msl
- Top of Spillway Gates (closed): 1,423 feet msl
Intake structures
- Direct intake, no Surge Tanks
Outlet works
- River regulation is attained by flow over low-crested spillway and through turbines
Lake
- Upstream Drainage: 5,840 square miles
- Tributaries: Missouri River
- Shoreline length: 200 miles at 1,420 feet msl
- Length of full reservoir: 80 miles
- Surface acres: 56,884 acres
- Storage capacity: 1,798,000 acre-feet
- Maximum depth: 78 feet
- Annual Flood Ctrl & Multi-Use Zone (Elevation): 1,420 feet msl – 1,422 feet msl
- Exclusive Flood Ctrl Zone (Elevation): 1,422 feet msl – 1,423 feet msl
- Record Pool Elevation (Date): 1,422.1 feet msl (1991)
- Record Flow Prior to 2011 (Year): 74,000 cfs (1997)
- Record Flow (2011): 166,300 cfs (Mid June)