Paper Mill, also known as Perch Lake in Sparta, Wisconsin, is a gravity dam built in 1865 with a primary purpose of recreation. Situated on the La Crosse River in Monroe County, this dam stands at a height of 14 feet and has a structural length of 910 feet. With a storage capacity of 382 acre-feet and a drainage area of 143 square miles, Paper Mill provides not only recreational opportunities but also contributes to flood control and water management in the region.

Despite being classified as low hazard potential with fair condition assessment, Paper Mill poses a very high risk due to its age and years of modification since 1925. The dam is under state jurisdiction and regulated by the Wisconsin Department of Natural Resources, with regular inspections and enforcement. The last inspection in September 2014 revealed no significant issues, but ongoing risk assessment and management measures are necessary to ensure the safety and integrity of this historic structure.

With its controlled spillway and historical significance, Paper Mill serves as a valuable asset for the community and the environment. As water resource and climate enthusiasts, it is essential to stay informed about the condition and management of such dams to protect both human life and natural ecosystems. Continued monitoring and maintenance of Paper Mill will help sustain its functions for future generations to enjoy and appreciate.