Dd No 109 is a local government-owned earth dam located in LeRoy, Kansas, designed by Strobel, Cook, and Flatt. Completed in 1998 for flood risk reduction purposes, this dam stands at a height of 22.5 feet and has a length of 842 feet. With a storage capacity of 205.81 acre-feet, it serves to control debris and reduce the risk of flooding in the area. The dam is situated on the South Big Creek-TR river and has a low hazard potential with a moderate risk assessment rating.

Despite its modest hazard potential, Dd No 109 plays a crucial role in managing flood risk in Coffey County, Kansas. The dam's construction was funded and overseen by local government authorities, with no federal agency involvement in its design, construction, or regulation. While the dam has not been inspected or assessed in recent years, it continues to provide valuable flood protection to the surrounding area, with a normal storage capacity of 17.77 acre-feet and a maximum discharge of 661 cubic feet per second.

As climate change continues to impact weather patterns and water resources, structures like Dd No 109 are essential for safeguarding communities against the threat of flooding. By effectively controlling debris and reducing flood risks, this earth dam plays a crucial role in protecting the residents of LeRoy and the wider Coffey County region. With a focus on flood risk reduction and a history of successful operation since its completion in 1998, Dd No 109 remains a vital component of the local water resource management system in Kansas.