Dd No Sp-4 is a locally owned earth dam located in Butler County, Kansas, specifically in the city of Potwin. Constructed in 1988 by designer Gene Bohnenblust, this dam serves the primary purpose of flood risk reduction along the Whitewater River. With a height of 21.8 feet and a length of 1000 feet, Dd No Sp-4 has a storage capacity of 365 acre-feet, with a normal storage level of 14.5 feet.

Despite its low hazard potential and moderate risk assessment, this dam has not been rated for its condition as of yet. The Kansas Department of Agriculture regulates and inspects Dd No Sp-4, ensuring that it is in compliance with state regulations. While it does not have any outlet gates, the dam features an uncontrolled spillway with a width of 50 feet to manage excess water flow during times of high discharge. Overall, Dd No Sp-4 plays a crucial role in mitigating flood risks in the area and protecting nearby communities from potential water-related disasters.