Gammon, located in Johnson, Wyoming, is a privately owned irrigation dam on T. A. Creek completed in 1974. With a height of 24 feet and a length of 1120 feet, this earth dam serves the primary purposes of flood risk reduction and irrigation, providing a storage capacity of 86 acre-feet. Despite its low hazard potential, the dam's structural condition is assessed as poor, emphasizing the need for regular inspections and maintenance.

The dam features an uncontrolled spillway with a width of 30 feet and a maximum discharge capacity of 271 cubic feet per second. The surrounding area has a drainage area of 0.5 square miles, with a normal storage capacity of 46 acre-feet. The dam's poor condition assessment raises concerns about its long-term reliability and underscores the importance of risk management measures to ensure the safety of downstream communities and agricultural lands.

As a vital water resource infrastructure in Wyoming, Gammon serves as a critical component of the local irrigation system, highlighting the intersection of water management and climate resilience. With its outdated design and poor condition, the dam presents challenges that must be addressed through proactive monitoring, maintenance, and potential rehabilitation efforts to safeguard its functionality and mitigate potential risks to the surrounding ecosystem and community.