Dd No 21, located in Pottawatomie County, Kansas, is a crucial flood risk reduction structure designed by F. V. Robbins and completed in 2009. This earth dam stands at a height of 42 feet and spans 680 feet in length, with a storage capacity of 691 acre-feet and a drainage area of 2.48 square miles. The dam is regulated by the Kansas Department of Agriculture and undergoes regular inspections to ensure its structural integrity and effectiveness in mitigating flood risks along Wilson Creek.

With a significant hazard potential and a moderate risk assessment rating, Dd No 21 plays a vital role in protecting the surrounding community from potential flooding events. The dam features an uncontrolled spillway with a width of 40 feet and has no outlet gates. Despite its condition being not rated, the dam is subject to a rigorous inspection schedule every 5 years to assess any maintenance or repair needs. The structure is owned and operated by the local government, highlighting the collaborative effort in safeguarding water resources and enhancing climate resilience in the region.

As a key component in the flood risk reduction infrastructure of Kansas, Dd No 21 serves as a critical defense against potential inundation and protects downstream areas from the impacts of high discharge events. With its strategic location and hydraulic height considerations, the dam effectively manages floodwaters from Wilson Creek, ensuring the safety and well-being of the local community. The structure's construction and design reflect a commitment to sustainable water resource management and climate adaptation, underscoring the importance of proactive measures in safeguarding against natural disasters.