Illum Dam, located in Marshall County, Iowa, is a privately-owned structure designed by NRCS for fire protection and as a stock or small fish pond. Completed in 2002, this earth dam stands at a height of 27 feet and spans a length of 490 feet, with a storage capacity of 117 acre-feet. The dam serves the purpose of regulating water flow in the TR- North Timber Creek and has a low hazard potential.

Despite its moderate risk assessment, Illum Dam has not been rated for its condition and does not have an Emergency Action Plan in place. The dam features an uncontrolled spillway with a width of 3 feet and is inspected, permitted, and regulated by the Iowa DNR. With a surface area of 9.4 acres and a drainage area of 0.35 square miles, the dam plays a crucial role in water resource management in the region. For water resource and climate enthusiasts, Illum Dam represents a fascinating case study in dam construction and management in the state of Iowa.