TWIN FALLS
OperatingHydro power plant
- Capacity
- 53 MW
- Primary fuel
- Hydro
- County
- Twin Falls County
- Operator
- IDAHO POWER CO
- Status
- Operating
- Commissioned
- 1935
- EIA plant ID
- 821
- Generators
- 2
- Technology
- Conventional Hydroelectric
- Net generation (2024)
- 101 GWh
- Capacity factor (2024, EIA nameplate)
- 22%
- Data vintage
- EIA-860 2024 final; EIA-923 2022-2024 final
- Coordinates
- 42.5893, -114.3564
TWIN FALLS, a 53 MW Hydro power plant in Twin Falls County, Idaho. Operated by IDAHO POWER CO, commissioned 1935.
How TWIN FALLS compares
With 53 MW of capacity, TWIN FALLS ranks 22nd among the 123 operating power plants Bywatts maps in Idaho and 11th of the 70 operating Hydro plants in the state. It accounts for about 2.1% of Idaho's operating Hydro capacity and 1.1% of all operating capacity in the state. Nationally it is the 272nd-largest of the 1,243 operating Hydro plants in the database. Commissioned in 1935, it is older than 90% of the 121 operating Idaho plants with a recorded commissioning year. Its operator, IDAHO POWER CO, runs 20 operating plants in Idaho totaling 1,894 MW. It shares Twin Falls County with 21 other operating plants, including HIGH MESA ENERGY LLC and PAYNE'S FERRY.
EIA-860 lists 2 generators at the site with 53 MW of nameplate capacity, all conventional hydroelectric technology. Net generation was 101 GWh in 2024 (a 22% capacity factor). Its generators came online between 1935 and 1995.
Grid neighborhood
The nearest named substation is KIMBERLY (138 kV), about 3.3 miles away; the closest transmission line found within 10 miles is a 138 kV line owned by IDAHO POWER CO, under 0.1 miles away. Another 21 operating power plants totaling 182 MW sit within 25 miles; the largest is MILNER HYDRO (60 MW, Hydro).
Computed by Bywatts from HIFLD power plant, substation and transmission line records and EIA-860/923 survey data; distances are straight-line. Sources and methodology
Weather peril exposure
TWIN FALLS is a 53 MW hydro power plant in Twin Falls County, ID, operated by IDAHO POWER CO, commissioned in 1935. Twin Falls County carries low modeled catastrophe exposure in the FEMA National Risk Index, scoring 1.7 of 5 at the 18th national percentile. Wildfire is the leading peril, rated Relatively Moderate by FEMA at the 98th 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.
Twin Falls County hazard ratings
| Peril | FEMA rating | National percentile | Peril score | Events per year |
|---|---|---|---|---|
| Wildfire | Relatively Moderate | 98th | 4.9 of 5 | 0.02 |
| Earthquake | Relatively Low | 69th | 3.8 of 5 | <0.01 |
| Heat wave | Relatively Moderate | 59th | 3.3 of 5 | 3.2 |
| Winter weather | Relatively High | 27th | 2.1 of 5 | 11.8 |
| Strong wind | Relatively Low | 21st | 1.9 of 5 | 0.31 |
| Hail | Very Low | 21st | 1.8 of 5 | 0.21 |
| Lightning | Relatively Low | 15th | 1.6 of 5 | 23.8 |
| Tornado | Very Low | 10th | 1.4 of 5 | 0.13 |
| Ice storm | Relatively Low | 8th | 1.3 of 5 | 0.05 |
| Riverine flooding | Relatively Low | 6th | 1.2 of 5 | 0.32 |
Perils not assessed in Twin Falls 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 Twin Falls 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.