Dd No 11, also known as Cedar Creek Watershed Dam No 11, is a local government-owned structure located in the city of Altoona, Kansas. This earth dam, designed by the USDA NRCS, serves the primary purpose of flood risk reduction along the Big Cedar Creek-TR. With a height of 22 feet and a hydraulic height of 18 feet, the dam provides a maximum storage capacity of 413.28 acre-feet and a normal storage of 45 acre-feet, covering a surface area of 16.18 acres.

Although Dd No 11 has a low hazard potential and is currently rated as "Not Rated" in terms of condition assessment, it is regulated by the Kansas Department of Agriculture and undergoes regular state inspections, permitting, and enforcement. The dam features an uncontrolled spillway with a width of 154 feet and has not undergone any modifications since its completion. Despite its moderate risk level, the structure has not been assigned a Dam Safety Action Classification (DSAC) date.

Overall, Dd No 11 plays a crucial role in managing flood risks in the Wilson County area of Kansas, providing essential protection to the surrounding community. With its solid construction and state-regulated operations, the dam stands as a reliable asset for water resource and climate enthusiasts interested in the preservation and sustainable management of water infrastructure.