Gillespie Dam, located in Maricopa, Arizona, along the Gila River, is a historic structure completed in 1921 primarily for irrigation purposes. This multi-arch dam stands at a height of 21 feet, with a hydraulic height of 26.7 feet and a structural height of 66 feet. It has a length of 1768 feet and a storage capacity of 3600 acre-feet.

Managed by a private owner, Gillespie Dam is regulated by the Arizona Department of Water Resources and undergoes regular inspections, with a significant hazard potential but a moderate risk assessment rating. The dam has a spillway width of 1657 feet and can discharge up to 130,000 cubic feet per second. Despite its age, the condition of Gillespie Dam is currently not rated, and it is situated in an area with a drainage area of 4965 acres.

Enthusiasts of water resources and climate will find Gillespie Dam an intriguing landmark, not only for its irrigation purposes and historical significance but also for its role in managing water resources in the region. As a regulated structure with a significant hazard potential, the dam presents both challenges and opportunities for ensuring its continued safety and effectiveness in water management along the Gila River.