Monroe Twp 3 is a local government-owned Earth dam located in Lyon, Minnesota, designed by the County Highway Department to serve the primary purpose of flood risk reduction along the Cottonwood River. Completed in 2007, this dam stands at a height of 27 feet with a structural height of 37 feet and a length of 700 feet. With a storage capacity of 100 acre-feet and a drainage area of 6 square miles, Monroe Twp 3 plays a crucial role in mitigating potential flood hazards in the area.

Managed by the Minnesota Department of Natural Resources, this dam has been deemed to have a low hazard potential and fair condition assessment as of the last inspection in May 2018. Despite its moderate risk rating, Monroe Twp 3 is equipped with uncontrolled spillways and falls under state jurisdiction with regular inspections, permitting, and enforcement in place. Situated within the Omaha District, this dam provides essential flood protection for the city of Lamberton and surrounding areas, ensuring the safety and security of the local community.

Water resource and climate enthusiasts will appreciate the strategic location and design of Monroe Twp 3, which effectively reduces flood risks along the Cottonwood River. With its sturdy Earth construction and state-regulated operations, this dam serves as a critical infrastructure for flood management in Lyon County, Minnesota. As climate conditions continue to evolve, the importance of structures like Monroe Twp 3 in safeguarding communities against water-related disasters cannot be understated.