Twenty Four Mile is a privately owned dam located in Chesterfield, Idaho, with a significant hazard potential and a fair condition assessment. Completed in 1928, this Earth dam stands at a height of 27.4 feet and has a hydraulic height of 21.8 feet, providing a storage capacity of 700 acre-feet for water from Twentyfour Mile Creek and Portneuf River. The dam spans 1100 feet in length, with a spillway width of 20 feet for uncontrolled discharge.

Managed by the Idaho Department of Water Resources, Twenty Four Mile is subject to state regulation, permitting, inspection, and enforcement to ensure its safety and compliance with guidelines. The dam's surrounding area covers a drainage area of 7.8 square miles, with a surface area of 44 acres. Despite its moderate risk assessment, the dam has not been modified in recent years, and its last inspection in August 2020 indicated a fair condition, highlighting the need for ongoing monitoring and maintenance to mitigate potential risks and ensure its long-term functionality.

For water resource and climate enthusiasts, Twenty Four Mile presents a fascinating case study of a historic dam in Idaho that continues to play a crucial role in water management and flood control. With its unique design features, storage capacity, and regulatory oversight, this dam serves as a valuable asset in the region's water infrastructure, demonstrating the importance of proactive risk management and maintenance to safeguard against potential hazards and ensure the safety of surrounding communities and ecosystems.