Allison Dam, located in El Dorado, Kansas, is a privately owned earth dam built in 1970 for fire protection, stock, and small fish pond purposes. The dam stands at a height of 20.3 feet with a hydraulic height of 21 feet and a structural height of 22 feet, providing a storage capacity of 64.5 acre-feet. The dam spans 600 feet in length and has a surface area of 5.6 acres, serving the West Branch Walnut River-TR.

With a significant hazard potential and a moderate risk assessment rating, Allison Dam is subject to state regulation, inspection, and enforcement to ensure its safety and integrity. The dam has a spillway type of uncontrolled with a width of 25 feet, and no outlet gates. While the condition assessment is not rated, the dam undergoes inspections every five years to monitor its performance and identify any potential risks. Despite its age, Allison Dam continues to play a crucial role in providing essential water resources for the surrounding area.