Wayne County Roadgrade Dam 3-70-21, located in Rathbun Reservoir, Iowa, is a vital structure owned by the local government and regulated by the Iowa Department of Natural Resources. Built in 1967 by the USDA NRCS, this earth dam stands at 23 feet tall with a length of 484 feet, providing a storage capacity of 62 acre-feet. The dam serves as a crucial barrier on TR- LOST BRANCH, contributing to flood control and water resource management in the region.

Despite its low hazard potential and moderate risk assessment, Wayne County Roadgrade Dam 3-70-21 has not been rated for its condition assessment. The dam's purpose is categorized as "Other," and it features an uncontrolled spillway type. With a surface area of 3.4 acres and a drainage area of 0.31 square miles, the dam plays a significant role in the local ecosystem and water flow dynamics. While it has not been inspected recently, the dam's construction and design by the Natural Resources Conservation Service ensure its structural integrity and efficiency in managing water resources for the community.