Waterloo Milldam is a historic gravity dam located on the Cedar River in Black Hawk County, Iowa. Built in 1915, this multi-arch dam stands at a height of 7 feet and has a length of 546 feet, providing a storage capacity of 882 acre-feet. The dam serves the primary purpose of regulating water flow and has a low hazard potential, with a satisfactory condition assessment as of October 2013.

Managed by the Iowa Department of Natural Resources, Waterloo Milldam is state-regulated and undergoes regular inspections every five years. The dam has a moderate risk assessment level of 3 and is considered to have a moderate risk management measure in place. Despite its age, Waterloo Milldam continues to play a crucial role in water resource management and serves as a reminder of the region's rich history of harnessing water for various purposes. Located in the city of Waterloo, this dam is an important part of the local government's efforts to ensure water safety and security for the community.