Dd No 21, located in Greenwood County, Kansas, is a local government-owned earth dam designed by the USDA NRCS and completed in 1986 for the primary purpose of flood risk reduction along the Homer Creek-TR. With a height of 21.3 feet and a length of 1100 feet, this dam has a storage capacity of 263.2 acre-feet and a normal storage capacity of 31.7 acre-feet, serving a drainage area of 0.7 square miles.

Despite its low hazard potential and moderate risk assessment rating, Dd No 21 is regulated, permitted, inspected, and enforced by the Kansas Department of Agriculture, indicating a commitment to ensuring its safety and functionality. The dam features an uncontrolled spillway with a width of 40 feet and no outlet gates, contributing to its flood risk reduction capabilities. While the condition assessment is currently not rated, the dam's risk management measures and emergency action plan status are not provided, suggesting potential areas for improvement in risk mitigation strategies.

Overall, Dd No 21 stands as a vital infrastructure asset in the region's water resource management efforts, showcasing the collaboration between local government and state regulatory agencies in safeguarding communities against flood risks. As water resource and climate enthusiasts, monitoring the ongoing maintenance and safety measures for dams like Dd No 21 is essential to ensure their continued effectiveness in protecting the surrounding areas from potential flooding events.