Wagner Dam, located in Guernsey, Iowa, is a private-owned structure designed by the USDA NRCS for grade stabilization along the Tr- North English River. Completed in 2001, this earth dam stands at 29 feet in height and spans 410 feet in length, with a storage capacity of 81 acre-feet. Its primary purpose is grade stabilization, serving to control the flow of water and prevent erosion in the surrounding area. Despite its low hazard potential, the dam is regulated, permitted, inspected, and enforced by the Iowa Department of Natural Resources to ensure its safety and compliance with state regulations.

With a moderate risk assessment rating, Wagner Dam has not been officially rated for its condition as of now. It features an uncontrolled spillway and covers a surface area of 5.9 acres, serving a drainage area of 0.22 square miles. Located within the Detroit District of the US Army Corps of Engineers, Wagner Dam plays a crucial role in managing water resources in Poweshiek County, Iowa. While it has not been modified in recent years, the dam remains an essential structure for water conservation and environmental protection in the region.