The Combined Locks Dam was originally constructed in 1889. The dam was reconstructed in 1912 and the overflow spillway was re-faced in the 1940’s.
In 1991, the overflow spillway and non-overflow spillway were strengthened with the installation of post-tensioned anchors. The tainter gates were replaced in 1998.
Until the 1970’s, the power was primarily used for paper mill operations. A new powerhouse was constructed in 1987. The upstream piers and walkway over the overflow spillway were reconstructed in 1987 in conjunction with the powerhouse construction. Some repairs to the tainter gate piers were also performed at that time.
The Combined Locks Hydro Project is located 1.5 miles upstream from the City of Kaukauna. From left to right looking downstream, the project structure consists of a 183-foot long non-overflow section, a 182-foot long spillway section with seven steel tainter gates operated by electric hoists.
A new reinforced concrete powerhouse was constructed in 1987. The powerhouse contains two horizontal shaft propeller type turbines. The maximum height of the dam above the stream bed is about 28 feet. The normal storage volume of the upstream pool is 1,600 acre-feet.
Both turbines have adjustable wicket gates and runner blades that are programmed to adjust to the correct pitch based on upstream and downstream water levels.