Hefley Dam, located in Marion, Kansas, is a privately owned earth dam primarily used for fish and wildlife pond purposes. With a height of 18.9 feet and a length of 1545 feet, the dam has a normal storage capacity of 49.9 acre-feet and a maximum storage capacity of 150.4 acre-feet. The dam is classified as low hazard potential with a moderate risk assessment rating.

Managed by the Kansas Department of Agriculture, Hefley Dam is regulated, permitted, inspected, and enforced by the state agency. The dam features an uncontrolled spillway with a width of 112 feet and no outlet gates. Although last inspected in June 2012, the condition assessment is currently not rated, and the emergency action plan status is unknown.

Water resource and climate enthusiasts interested in Hefley Dam can explore its location at 9,20S, 3E in Marion, Kansas. While the dam's associated structures and potential modifications remain undisclosed, its purpose as a fish and wildlife pond contributes to local ecological diversity. With a state-regulated status and state jurisdiction, Hefley Dam serves as a vital component in water management and conservation efforts in Kansas, offering a glimpse into the intersection of human activity and natural ecosystems.