Alliant Energy’s history is strongly tied to hydroelectric power and it continues to be an important part of our renewable energy portfolio. The Kilbourn Dam and the Prairie du Sac Hydro were among our first generating stations. The availability of power from these two power plants spurred the construction of transmission lines across the southern half of Wisconsin, as well as the consolidation of several community utility companies into what we now know as Wisconsin Power and Light, Alliant Energy’s Wisconsin utility subsidiary. 
These two hydroelectric dams are a testament to the fact that alternative energy sources are not necessarily “new.” With the mighty Wisconsin River as their power source, Kilbourn has been generating electricity for over a century and Prairie du Sac will soon celebrate its 100th anniversary as well. Both facilities have been incredibly reliable and consistent in bringing renewable electricity to our customers.
The Kilbourn Dam is a visible downtown Wisconsin Dells landmark that generates up to 10 megawatts of electricity. The Prairie du Sac Hydro is located about one mile north of Prairie du Sac, is responsible for the formation of Lake Wisconsin and has a capacity of about 29 megawatts. Alliant Energy also receives power from and owns a 50 percent interest in Wisconsin River Power Company, which operates the Petenwell and Castle Rock Dams on the Wisconsin River. Finally, our company has purchase power agreements with several other hydroelectric facilities across Wisconsin and Iowa, many of which we previously owned, that add to our renewable energy mix.
As part of our continuing effort to provide safe and reliable service to our customers, we are in the middle of a major improvement project at our Kilbourn and Prairie du Sac hydroelectric facilities. Part of this project includes the installation of a fish passage at our Prairie du Sac Hydro that is expected to be operational in 2015.
Additional resources
- Information on the Prairie du Sac Hydro fish passage
- Prairie du Sac water levels and flow rate
- Dam Safety information
- Lake Wisconsin Navigation Map
- For a daily, early morning update on Wisconsin River flows at the Castle Rock Dam, Prairie du Sac Hydro and Kilbourn Dam, call 1-800-242-1077.