Cottonwood Lake, located in Lyon County, Minnesota, is a privately owned reservoir that serves various purposes, including recreation and water storage. The dam, completed in 1960, is a gravity type with a height of 9 feet and a storage capacity of 3,582 acre-feet. With a surface area of 378 acres and a drainage area of 20.5 square miles, Cottonwood Lake plays a vital role in managing water resources in the region.

The dam is regulated and inspected by the Minnesota Department of Natural Resources, ensuring its safety and functionality. Despite being classified as having a low hazard potential, the dam is in satisfactory condition, as assessed in 2010. The last inspection in November 2018 confirmed its structural integrity, and emergency preparedness measures are in place to mitigate any potential risks. With its location on the Yellow Medicine River and its contribution to water storage and management, Cottonwood Lake is a significant resource for the local community and environmental enthusiasts.

Overall, Cottonwood Lake stands as a testament to effective water resource management in Minnesota, providing recreational opportunities while ensuring the safety and sustainability of the surrounding ecosystem. Its role in regulating water flow and storage in the region, along with its low hazard potential and satisfactory condition, highlights the importance of maintaining and monitoring such infrastructure to mitigate potential risks and ensure the long-term health of our water resources and climate.