New Richmond Mills, located in New Richmond, Wisconsin, is a gravity dam built in 1812 on the Willow River for the primary purpose of recreation. With a structural height of 19 feet and a capacity of 1500 acre-feet, this dam has a significant impact on the local ecosystem and water resources. The dam, with a drainage area of 146 square miles, plays a crucial role in providing water for fish and wildlife ponds and recreational activities in the area.

Despite being considered a high hazard potential structure, the dam is currently in satisfactory condition, as assessed in October 2019. With a very high risk assessment rating, there is a need for effective risk management measures to ensure the safety of the surrounding community and ecosystem. The dam has undergone modifications in 1925, 1997, and 1999, highlighting the significance of regular inspections and maintenance to keep the structure functioning effectively. Overall, New Richmond Mills serves as a vital water resource and recreational site, contributing to the local economy and environment in St. Croix County, Wisconsin.