Mystic Reservoir Dam, located in Appanoose County, Iowa, is a vital structure managed by the local government for fire protection, stock, and small fish pond purposes. Built in 1930 by the USDA SCS, this earth dam stands at a height of 31 feet and has a length of 555 feet. With a storage capacity of 101 acre-feet and a surface area of 8 acres, the dam serves the Little Walnut Creek watershed, providing water supply and flood control benefits to the surrounding area.

Despite its low hazard potential and satisfactory condition assessment, Mystic Reservoir Dam is regulated and inspected by the Iowa Department of Natural Resources. The dam's spillway, classified as uncontrolled, has a width of 2 feet, ensuring proper water flow during peak discharge events. While the risk assessment indicates a moderate risk level, the dam has not been modified in recent years, and emergency action plans are yet to be prepared and updated. With its strategic location and functions, Mystic Reservoir Dam plays a crucial role in water resource management and climate resilience efforts in the region.