Leo Johnson Lake Dam, located in Whiteside, Illinois, is a privately owned earth dam completed in 1962 primarily for recreational purposes. The dam stands at a height of 20 feet and spans 520 feet in length, with a maximum storage capacity of 78 acre-feet. It is situated on the TRIB ELKHORN CREEK and is regulated by the Illinois Department of Natural Resources (IDNR).

Despite being classified as having a low hazard potential, the dam is subject to state regulation, inspection, and enforcement to ensure its safety and structural integrity. With an uncontrolled spillway and outlet gates, the dam's risk assessment is considered moderate. While the condition assessment is not available, the last inspection took place in September 2015, with a recommended inspection frequency of 5 years. Overall, Leo Johnson Lake Dam serves as a vital recreational water resource in the region, offering opportunities for outdoor activities while being closely monitored for safety and risk management.