PRAIRIE DU SAC
OperatingHydro power plant
- Capacity
- 31 MW
- Primary fuel
- Hydro
- County
- Sauk County
- Operator
- WISCONSIN POWER & LIGHT CO
- Status
- Operating
- Commissioned
- 1915
- EIA plant ID
- 4056
- Coordinates
- 43.3100, -89.7276
PRAIRIE DU SAC, a 31 MW Hydro power plant in Sauk County, Wisconsin. Operated by WISCONSIN POWER & LIGHT CO, commissioned 1915.
Weather peril exposure
PRAIRIE DU SAC is a 31 MW hydro power plant in Sauk County, WI, operated by WISCONSIN POWER & LIGHT CO, commissioned in 1915. Sauk County carries critical modeled catastrophe exposure in the FEMA National Risk Index, scoring 4.3 of 5 at the 84th national percentile. Lightning is the leading peril, rated Relatively Low by FEMA at the 96th 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.
Sauk County hazard ratings
| Peril | FEMA rating | National percentile | Peril score | Events per year |
|---|---|---|---|---|
| Lightning | Relatively Low | 96th | 4.8 of 5 | 35.6 |
| Hail | Relatively Moderate | 87th | 4.5 of 5 | 3.5 |
| Riverine flooding | Relatively Moderate | 72nd | 3.9 of 5 | 1.8 |
| Heat wave | Relatively Low | 67th | 3.7 of 5 | 3.3 |
| Tornado | Relatively Moderate | 58th | 3.3 of 5 | 0.54 |
| Strong wind | Relatively Moderate | 33rd | 2.3 of 5 | 3.6 |
| Wildfire | Very Low | 29th | 2.2 of 5 | <0.01 |
| Earthquake | Very Low | 11th | 1.4 of 5 | <0.01 |
| Ice storm | Relatively Low | 8th | 1.3 of 5 | 0.40 |
| Winter weather | Relatively Low | 7th | 1.3 of 5 | 14.6 |
| Hurricane | Very Low | 1st | 1.0 of 5 | <0.01 |
Perils not assessed in Sauk 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 |
|---|---|
| Coastal flooding | FEMA rating is "Not Applicable" for this county |
Model hail, wind and flood exposure for Sauk 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.