Maquoketa Milldam, located in Maquoketa, Iowa, is a historic gravity dam completed in 1923 for hydroelectric power generation and recreation purposes. The dam, standing at 26 feet tall and spanning 700 feet in length, harnesses the Maquoketa River's flow to store up to 4,419 acre-feet of water for various uses. With a surface area of 340 acres and serving a drainage area of 953 acres, the dam's controlled spillway type ensures proper water management while maintaining a low hazard potential.

Managed by the Iowa Department of Natural Resources, Maquoketa Milldam has been deemed in satisfactory condition as of the latest assessment in 2016, with a very high risk rating due to its age and potential impact on the surrounding area. Despite its historical significance and recreational value, the dam has not undergone any major modifications in recent years, with the last inspection conducted in 2007. As a key structure in the region's water resource management, Maquoketa Milldam serves as a reminder of the intersection between nature, infrastructure, and climate resilience in the face of changing environmental conditions.