BIG BEND
OperatingHydro power plant
- Capacity
- 494 MW
- Primary fuel
- Hydro
- County
- Buffalo County
- Operator
- USCE-MISSOURI RIVER DISTRICT
- Status
- Operating
- Commissioned
- 1964
- EIA plant ID
- 3375
- Generators
- 8
- Technology
- Conventional Hydroelectric
- Net generation (2024)
- 813 GWh
- Capacity factor (2024, EIA nameplate)
- 17%
- Data vintage
- EIA-860 2024 final; EIA-923 2022-2024 final
- Coordinates
- 44.0384, -99.4463
BIG BEND, a 494 MW Hydro power plant in Buffalo County, South Dakota. Operated by USCE-MISSOURI RIVER DISTRICT, commissioned 1964.
How BIG BEND compares
With 494 MW of capacity, BIG BEND ranks 2nd among the 28 operating power plants Bywatts maps in South Dakota and 2nd of the 3 operating Hydro plants in the state. It accounts for about 31% of South Dakota's operating Hydro capacity and 12% of all operating capacity in the state. Nationally it is the 47th-largest of the 1,243 operating Hydro plants in the database. Commissioned in 1964, it is older than 80% of the 26 operating South Dakota plants with a recorded commissioning year. Its operator, USCE-MISSOURI RIVER DISTRICT, runs 3 operating plants in South Dakota totaling 1,598 MW.
EIA-860 lists 8 generators at the site with 538 MW of nameplate capacity, all conventional hydroelectric technology. Net generation was 813 GWh in 2024 (a 17% capacity factor), up 4% from 2022. Its generators came online between 1964 and 1966.
Grid neighborhood
The closest transmission line found within 10 miles is a 230 kV line owned by WAPA-- WESTERN AREA POWER ADMINISTRATION, under 0.1 miles away. One other operating power plant sits within 25 miles: SOUTH DAKOTA WIND ENERGY CENTER (41 MW, Wind).
Computed by Bywatts from HIFLD power plant and transmission line records and EIA-860/923 survey data; distances are straight-line. Sources and methodology
Weather peril exposure
BIG BEND is a 494 MW hydro power plant in Buffalo County, SD, operated by USCE-MISSOURI RIVER DISTRICT, commissioned in 1964. Buffalo County carries elevated modeled catastrophe exposure in the FEMA National Risk Index, scoring 3.1 of 5 at the 52nd national percentile. Winter weather is the leading peril, rated Relatively Low by FEMA at the 93rd 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.
Buffalo County hazard ratings
| Peril | FEMA rating | National percentile | Peril score | Events per year |
|---|---|---|---|---|
| Winter weather | Relatively Low | 93rd | 4.7 of 5 | 16.6 |
| Wildfire | Relatively Low | 90th | 4.6 of 5 | <0.01 |
| Riverine flooding | Very Low | 87th | 4.5 of 5 | 0.57 |
| Heat wave | Very Low | 80th | 4.2 of 5 | 4.8 |
| Ice storm | Relatively Low | 70th | 3.8 of 5 | 0.38 |
| Strong wind | Relatively Low | 69th | 3.8 of 5 | 2.8 |
| Tornado | Very Low | 60th | 3.4 of 5 | 0.19 |
| Hail | Very Low | 58th | 3.3 of 5 | 4.0 |
| Lightning | Very Low | 42nd | 2.7 of 5 | 35.8 |
| Earthquake | Very Low | 25th | 2.0 of 5 | <0.01 |
Perils not assessed in Buffalo 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 Buffalo 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.