A former undeveloped site near the corner of Route 63, Philmont Avenue and Red Lion Road in the Lower Moreland Township, PA was the proposed site for a 4,000-square-foot Wawa with 12 pumping stations.
The site had three significant challenges. First, the site needed a stormwater detention system to manage the runoff from the large parking area. Second, the site was located on a downward graded lot adjacent to a creek and flood plain, so any solution had to address flood control. Lastly, due to its proximity to residential development, it was essential that the structure be aesthetically pleasing and complement the site’s appearance. The Contech design team formulated a solution to address all three issues.
The design team selected Terre Arch, a modular precast concrete stormwater storage system engineered especially for underground installation. Terre Arch provided the load rating (rated for HS-25), storage volume (277 – 541 CF per arch), and fast installation (5 minutes per arch) needed on this site.
In addition, the Terre Arch system was customized to meet the unique site conditions – specifically the grading of the site and managing the water from the adjacent flood plain. Distribution boxes customized to act as retaining walls were constructed to keep the parking area at proposed grade level. The retaining wall, which faced the flood plain, contains openings to allow flood water to enter the system. The stormwater runoff and flood waters are stored in the Terre Arch chambers and released at a controlled rate into the exiting storm line at the street.
The retaining wall was designed with a custom finish to ensure the structure was aesthetically pleasing, and also included a custom cap which also acted as a curb for the parking area.
Paul Harris, Construction Manager for the project had this to say about Contech. “Contech provided an innovative, cost effective, solution to a flood plain challenge that enabled our development project to move forward. Their team solved both technical and aesthetic design issues, which kept both the engineers, property owners and neighbors happy”