Magma Dam Flood Retarding Structure

Magma Dam Flood Control District | Pinal County, Arizona

The Magma Flood Retarding Structure (FRS) was originally constructed by the Soil Conservation Service (now the Natural Resources Conservation Service-NRCS) in 1964, and is operated and maintained by the Magma Flood Control District. The 5.5-mile-long earthen structure provides flood protection to a portion of the Town of Florence, Arizona, including 1,100 residents and 500 residential and commercial properties.

The FRS developed safety deficiencies and inadequacies since the time of its construction related to embankment cracking and emergency spillway capacity. To address these concerns, EPS Group provided the design of the modification of the emergency spillway channel from the spillway to the principle outlet (approximately 4,500 linear feet), 5,300 linear feet of improvements to the outlet channel, and placement of four inlet structures.

A key component of the Magma FRS rehabilitation was the installation of a new central filter element. EPS also provided construction management services to the District working closely with the Arizona Department of Water Resources and the Natural Resources Conservation Service (NRCS).