OAHE
OperatingHydro power plant
- Capacity
- 784 MW
- Primary fuel
- Hydro
- County
- Hughes County
- Operator
- USCE-MISSOURI RIVER DISTRICT
- Status
- Operating
- Commissioned
- 1962
- EIA plant ID
- 3356
- Coordinates
- 44.4504, -100.3866
OAHE, a 784 MW Hydro power plant in Hughes County, South Dakota. Operated by USCE-MISSOURI RIVER DISTRICT, commissioned 1962.
Weather peril exposure
OAHE is a 784 MW hydro power plant in Hughes County, SD, operated by USCE-MISSOURI RIVER DISTRICT, commissioned in 1962. Hughes County carries moderate modeled catastrophe exposure in the FEMA National Risk Index, scoring 2.0 of 5 at the 25th national percentile. Winter weather is the leading peril, rated Relatively Moderate by FEMA at the 97th percentile.
The Bywatts loss layer is calibrated to solar PV hardware, so it is not applied to a hydro plant. The ratings below are the FEMA National Risk Index county hazard ratings for this location.
Hughes County hazard ratings
| Peril | FEMA rating | National percentile | Peril score | Events per year |
|---|---|---|---|---|
| Winter weather | Relatively Moderate | 97th | 4.9 of 5 | 16.5 |
| Riverine flooding | Very Low | 87th | 4.5 of 5 | 1.1 |
| Wildfire | Relatively Low | 84th | 4.4 of 5 | <0.01 |
| Heat wave | Very Low | 78th | 4.1 of 5 | 4.3 |
| Ice storm | Relatively Low | 71st | 3.8 of 5 | 0.45 |
| Strong wind | Relatively Low | 54th | 3.2 of 5 | 2.6 |
| Tornado | Relatively Low | 38th | 2.5 of 5 | 0.24 |
| Hail | Very Low | 33rd | 2.3 of 5 | 3.2 |
| Lightning | Very Low | 29th | 2.2 of 5 | 33.9 |
| Earthquake | Very Low | 20th | 1.8 of 5 | <0.01 |
Perils not assessed in Hughes County
These perils carry no usable National Risk Index figure for this county, so they are excluded from the scoring rather than scored zero. A zero would claim the peril was assessed and found benign.
| Peril | Why it is not scored |
|---|---|
| Hurricane | FEMA rating is "Not Applicable" for this county |
| Coastal flooding | FEMA rating is "Not Applicable" for this county |
Model hail, wind and flood exposure for Hughes County in the weather risk calculator
Ratings are the FEMA National Risk Index county hazard ratings; the peril score is a Bywatts transform of the FEMA national percentile. Full data sources and the solar vulnerability methodology are in the weather risk calculator.
Modeled estimate for screening and negotiation. Built from FEMA National Risk Index county hazard data and a solar vulnerability layer documented above. Not a quote, a binder, or actuarial advice, and not a substitute for a carrier's own model. Hazard data: FEMA National Risk Index December 2025, synced 2026-07-24. Resolution is county level, not site level.