Wisconsin Power and Light Company: Starting hydro improvement projects

Media Contact: Scott Reigstad (608) 458-3145

Reliability and safety investments being made at Wisconsin River dams

MADISON, WI – September 23, 2009 – Wisconsin Power and Light (WPL), an Alliant Energy company, has begun a multi-year safety, reliability and economic development initiative that will include significant and multiple improvement projects at its Prairie du Sac and Kilbourn Hydroelectric Generating Stations on the Wisconsin River. Implementing a multi-faceted dam improvement plan will ensure that the facilities are producing clean, renewable energy well into the future.

“We believe it is the right time to move ahead with an action plan to improve our hydroelectric power plants, both of which were built in the early 1900s,” said Barbara Swan, WPL President. “These facilities have been among the most dependable and reliable of our generating fleet and we are going to perform work at the dams that will lay the groundwork for many more years of productive operation.”

The dam improvement projects are starting this week with work on the Prairie du Sac Dam’s east embankment. The east embankment runs along the frontage of the Lake Wisconsin Country Club golf course. To bolster the strength of the embankment and further enhance safety, several hundred tons of soil will be added that will improve the slope of the terrain. The project will take place over 6-8 weeks, with completion slated for early November.

The east embankment upgrade represents an estimated $600,000 investment by WPL and will be the first of many steps taken during the multi-year improvement process. Future steps and details will be announced as internal planning is completed and necessary regulatory approvals and guidelines are obtained. Several actions are being targeted for initiation in 2009 and 2010, with the expectation that improvements will continue for several years and could include tens of millions of dollars in total investment.

“We’re planning to invest significantly in our hydroelectric facilities over the coming years so that they are available to produce “green” power for the next several generations of our customers,” said John Larsen, Alliant Energy Vice President of Generation. “Alliant Energy is committed to the economic development of the Prairie du Sac, Sauk City and Wisconsin Dells areas and keeping these dams in good condition will continue to benefit the region and the State of Wisconsin.”

Both dams played and continue to play a critical role in encouraging tourism and promoting economic development in south-central Wisconsin with their long histories that trace back to the early 1900s and the beginnings of WPL.

The 100-year-old Kilbourn Dam was constructed during a three-year period from 1906 to 1909 and the first electric power was generated from the facility on August 9, 1909. The structure was actually one of five dams built on or near the same site from the 1855 to 1909 timeframe. At the time it was completed, it was the largest dam west of Niagara Falls and was viewed as a modern engineering marvel. It also played a key role in transforming the Wisconsin Dells area into one of the world’s leading vacation destinations and is largely responsible for the formation of WPL. WPL recently celebrated 100 years of operations at the Kilbourn Dam.

The 95-year-old Prairie du Sac Dam was built from 1911 until 1914 and began production in September 1914. Once completed, the Prairie du Sac Dam not only generated power, but like its counterpart, helped to boost tourism in the area where it is located by creating popular Lake Wisconsin. It also helped to spur the formation of WPL. WPL purchased both the Kilbourn and Prairie du Sac dams in 1917. Combined, the capacity of the two generating stations is roughly 40 megawatts of electricity, enough to power about 40,000 homes with renewable energy.