Festival Shoppes is a new commercial development near Boca Raton, Florida. The development consists of 10,636 square feet of retail space and 6,225 square feet of restaurant space.
Designing a stormwater system for this site was challenging. The development was built in an urban environment on the site of a pre-existing above ground detention pond. In addition, there was limited distance between the water table and finished grade elevation, providing little vertical storage space. Because of the volume requirements, any underground system would need to encircle the entire building footprint of the building and be built underneath the parking lot. The system would need to provide a high volume of storage with little cover while maintaining traffic load.
Engineers from Kimley Horn and Associates worked with Contech Engineered Solutions to develop a solution consisting of Terre Arch, a modular, precast concrete stormwater storage system engineered especially for underground installation in shallow environments. With a load-bearing rating of HS-25, each section can support heavy gross weight trucks and machinery. In addition, Terre Arch required less cover than other solutions such as plastic chambers.
The project called for 367 Terre Arch 48 chambers and 43 distribution manifolds, providing 247,517 cubic feet of storage.
Fast installation was desired by the contractor, MDS Builders, because little staging area for product storage was available. With a properly excavated and prepared base, a Terre Arch can be set every five minutes; with installation of up to 50,000 ft³ of storage in one day. With the “just in time” delivery” of Terre Arch, sections could be lifted off the delivery trucks and lowered in place as fast as they were delivered.