Growing demand sparked a 44-acre expansion project at a UPS distribution center in Houston, TX. Built in phases, the project consisted of expanded parking areas and the build-out of a 660,739 SF distribution center.
Phase one of the project consisted of an expanded parking area for employees and trucks. Since there was no land available for an above-ground solution, the detention system was placed under the concrete parking lot. The detention system was constructed from 42,432 LF of 48" corrugated metal pipe (CMP), providing 533,216 cubic feet of storage. The system's design was challenging. There was limited depth, a continually changing parking lot design, obstacles such as light poles and landscaped traffic islands that had to be avoided and multiple inlet locations to the system. Contech Stormwater Design Engineers worked closely with the engineer of record and provided calculations, several design iterations and installation cost estimates to help the engineer better analyze the proposed solution.
Phase two consisted of the build-out of the distribution center. For this system, 29,852 LF of 96" and 500 LF of 18" CMP was used, providing 1,500,525 cubic feet of storage. While the soil in this area allowed for a larger diameter pipe, there were still challenges. Gas lines, water/fire lines, and an existing pump station needed to be avoided. Again, Contech Stormwater Design Engineers worked closely with the engineer of record and provided several design iterations until the final, optimized design was completed.
The flexibility of CMP proved valuable in Phase two. The system needed to be installed in phases, resulting in Contech providing bulkheads and stubs to cap off the detention system until an existing building could be torn down. Once the contractor removed the building, the detention system's last phase was installed and connected to the first section, completing the system.