David Downey Dam, located in Union County, Iowa, is a private dam designed by the USDA NRCS and completed in 2013 for grade stabilization purposes. The earth dam stands at a height of 34 feet and stretches 409 feet in length, with a storage capacity of 106 acre-feet. The dam serves multiple purposes including grade stabilization, recreation, and water supply for the surrounding area.

Despite its low hazard potential, the dam has a moderate risk assessment rating and is regulated by the Iowa Department of Natural Resources. It features an uncontrolled spillway with a width of 20 feet and a maximum discharge of 30 cubic feet per second. The dam's location on TR-Indian Creek in the Twelvemile Creek area makes it a crucial part of the local water resource infrastructure, supporting a drainage area of 0.3 square miles and providing important flood control measures for the region.

With its strategic design and construction, David Downey Dam plays a vital role in managing water resources in Union County, Iowa. The dam's presence not only ensures grade stabilization and water supply but also contributes to recreational activities in the area. As a privately owned structure, the dam is subject to state regulations and inspections, highlighting its importance in maintaining water quality and safety for the community.