Oahe

Hydro power plant · Hughes County, South Dakota

Nameplate capacity
786 MW
Rank in South Dakota
#1
of 54 plants
In service since
1962
April 1962

Details

Primary fuel
Hydro
Technology
Conventional Hydroelectric
Operator
USACE-Omaha
County
Hughes County
Generating units
7
Share of state capacity
10.25%
Rank among hydro plants in South Dakota
#1 of 4
EIA plant code
3356

Generating units

Individual generating units at Oahe
UnitTechnologyNameplateSummerOnlineStatus
1Conventional Hydroelectric112 MW102 MW1962Operating
2Conventional Hydroelectric112 MW102 MW1962Operating
3Conventional Hydroelectric112 MW102 MW1962Operating
4Conventional Hydroelectric112 MW102 MW1962Operating
5Conventional Hydroelectric112 MW102 MW1963Operating
6Conventional Hydroelectric112 MW102 MW1963Operating
7Conventional Hydroelectric112 MW102 MW1963Operating

Nameplate is the maximum rated output; summer capacity is what the unit can reliably deliver on a hot day, which is typically lower.

Similarly sized plants in South Dakota

Big Bend DamHydro538 MW
Big StoneCoal451 MW

About this data

From EIA’s inventory of operable generators, May 2026 release. Capacity is nameplate — the maximum rated output of the equipment, not what the plant actually generates over a year, which depends on how often it runs. A 786 MW solar plant and a 786 MW nuclear plant have the same entry here and produce very different amounts of electricity.

“In service since” is the earliest in-service date among the units still listed, so a site rebuilt around newer equipment can read as younger than the site itself. All South Dakota power plants · What South Dakota actually generates