Originally called the Trilby Wash Detention Basin Dam and constructed by the United States Army Corps of Engineers in 1954 and 1955, McMicken Dam is a long, earthen embankment. The 10-mile-long dam is located in Surprise and runs from Happy Valley Road to Peoria Avenue. Construction of McMicken Dam was authorized by Congress in 1953 to provide emergency flood protection for Luke Air Force Base, the Litchfield Park Naval Air Facility and adjacent areas. McMicken Dam functions as a flood control structure and is operated and maintained by the Flood Control District of Maricopa County (District) under the jurisdiction of the Arizona Department of Water Resources.
Extensive repairs to McMicken Dam were completed in the mid-1980s to repair severe embankment cracking. During the repairs, studies detected the presence of earth fissures near the south end of the dam. Additional studies were conducted in 2000 to further characterize the fissures near the embankment. The results of these additional studies indicate earth fissures and conditions sufficient for fissure development adjacent to the south end of McMicken Dam. Fissure development in the area is the result of subsidence of basin soils due to groundwater withdrawal. As the water table is lowered, the basin soils consolidate.
The District analyzed 23 alternative designs before selecting a preferred alternative to isolate the fissure risk zone from McMicken Dam. The final design considered alternative alignments and modifications or enhancements of elements of the planned construction, including a basin or basins. Final design of the project was completed by AMEC Earth and Environmental, Inc. and included the removal of the existing dam segment within an area with a high potential for earth fissures. The removed segment of the dam was replaced with a realigned soil-cement dam segment an basin located outside of the area determined having a high fissure risk potential. Construction began in March of 2005 and completed in August of 2006.
In addition, the Maricopa Regional Trail Corridor is located within the project area. The District’s consultant coordinated with a landscape architecture consultant in incorporating the requirements for a future trail as an integral part of the planning and compatible grading design criteria for the project.