The Mines of Spain Wetland Development Dam, located in Dubuque, Iowa, is a state-owned structure designed for recreational purposes along the TR-Mississippi River. Completed in 1996, this earth dam stands at a height of 11 feet and spans 952 feet in length, with a storage capacity of 145 acre-feet. While primarily serving as a recreational area, the dam also plays a role in water resource management for the surrounding area.

With a low hazard potential and a moderate risk assessment rating, the Mines of Spain Wetland Development Dam is regulated, permitted, inspected, and enforced by the Iowa Department of Natural Resources. This soil-based dam contributes to the conservation of water resources in the region, with a normal storage capacity of 51 acre-feet and a surface area of 13 acres. As a wetland development project, the dam provides valuable habitat for wildlife and contributes to the overall health of the ecosystem in the area.