Magma Retarding, located in Pinal, Arizona, is a privately owned structure designed by USDA NRCS with the primary purpose of flood risk reduction along the Gila River. Completed in 1964, this earth dam stands at a height of 21 feet and spans 28,900 feet in length. With a storage capacity of 18,684 acre-feet and a surface area of 935 acres, Magma Retarding plays a crucial role in managing water resources in the region.

Managed by the Arizona Department of Water Resources and regulated by state agencies, Magma Retarding has a high hazard potential but is currently in satisfactory condition. The structure features an uncontrolled spillway with a width of 150 feet and outlets that are also uncontrolled. Despite its moderate risk rating, Magma Retarding serves as a vital component of the flood control infrastructure in the area, helping to protect downstream communities and ecosystems from the impacts of extreme weather events.

As a key element of water resource management in Arizona, Magma Retarding underscores the importance of proactive maintenance and monitoring to ensure its continued effectiveness in mitigating flood risks. With its strategic location along the Gila River and strong regulatory oversight, this structure represents a valuable asset for climate resilience and disaster preparedness in the region.