Canby R-4a, located in Yellow Medicine, Minnesota, is a vital flood risk reduction structure designed by the USDA NRCS and regulated by the MNDNR EWR. Completed in 1982, this earth dam stands at a height of 41 feet and has a length of 1200 feet, providing storage of 770 acre-feet and serving a drainage area of 2.4 square miles. The dam's primary purpose is flood risk reduction, with a spillway type designated as 'Uncontrolled' and a hazard potential rated as 'High'.

With a satisfactory condition assessment as of March 2017, Canby R-4a is regularly inspected to ensure its structural integrity. The dam's risk assessment is classified as moderate, indicating a potential for adverse impacts if not properly managed. While the dam has no outlet gates, its primary design and construction were overseen by the Natural Resources Conservation Service, emphasizing the importance of effective water resource management and climate resilience in the region. Canby R-4a serves as a critical infrastructure for mitigating flood risks and protecting the surrounding community from potential water-related hazards.