Soap Creek Watershed Site 4-81, located in Appanoose, Iowa, is a flood risk reduction structure designed by the USDA NRCS in 2007. This earth dam stands at a height of 32 feet and stretches for 440 feet, with a storage capacity of 118 acre-feet. Serving its primary purpose of flood risk reduction, this site is regulated by the Iowa DNR and is inspected, permitted, and enforced by state agencies to ensure its safety and functionality. With a low hazard potential and a condition assessment of "Not Rated," this site plays a crucial role in protecting the surrounding area from potential flooding events.

Situated in the Selma city area and part of the Tributary to Buzzard Creek, Soap Creek Watershed Site 4-81 covers a drainage area of 0.43 square miles and has a maximum discharge capacity of 108 cubic feet per second. The dam's spillway width of 14 feet helps manage excess water during heavy rainfall events, while its stone core and soil foundation provide structural stability. Despite not being rated for condition assessment, this site is crucial for water resource and climate enthusiasts interested in flood risk reduction and watershed management efforts in Iowa.

Managed by the local government and funded by the Natural Resources Conservation Service, Soap Creek Watershed Site 4-81 is a vital component in the flood risk reduction infrastructure of the region. With a well-maintained outlet gate system and a storage capacity of 29 acre-feet under normal conditions, this site ensures the safety and protection of the community against potential flooding events. As part of the Rock Island District, this earth dam serves as a critical piece of infrastructure in the ongoing efforts to manage water resources and climate impacts in the area.