Upland Square Shopping Center is a 680,000 square foot new development in West Pottsgrove Township, just outside of Pottstown. Multiple BMPs were incorporated into the design and building of this site to meet the area’s stormwater management standards including a wet pond; rooftop rainwater capture and cistern system; restored landscape channels around the perimeter of the site; and bioretention areas within the parking islands.
Due to the existing layout of the site, Upland Square Shopping Center was designed around several sensitive, environmental features. One of these features was a perched wetland located towards the high point of the site. The wetlands area drained through an existing channel through the site. To enhance the existing wetlands area, several areas were graded and planted with wetlands species to promote expansion of the wetlands. Also, runoff from nearby roofs was captured and drained to a tank. Once the tank fills, it pumps the water up to the wetlands where it is discharged via a level spreader. There are many water quality and ecological restoration benefits that can be attributed to this BMP addition.
The 278,000 gallon wet pond is being utilized for stormwater management of larger storms, and also as a source of irrigation for the shopping center’s landscaping. Due to the presence of shallow bedrock at the site, alternative volume management BMPs were evaluated to mitigate runoff generated during the site’s post-development condition. Installing the wet pond yielded a 28,000 cubic foot volume credit towards meeting the NPDES requirements, while it also provides several days’ worth of irrigation supply in lieu of using the public water supply. Both water quality and runoff reduction on site have been improved with this feature.
Two existing channels crossed through the site and the divided the parcel into 3 separate sections. To increase the slope stability of the channels and provide additional shading to cool the ambient water temperature, over 1,550 whip plantings were installed. Along with the whips, non-native undergrowth was removed to provide the maximum growing potential for the whips. This has helped greatly with erosion control and water quality improvement, as well as offering the opportunity to introduce many native species to the site.
To aid with providing additional water quality, more than 20 parking islands were designed to eliminate direct runoff to the storm drain system and instead, allow runoff to enter a bioretention area, filter through the medium and then eventually infiltrate or enter the storm drain system via an under drain. Water-tolerant plantings were proposed with the bio-retention areas to aid in the reduction of volume via evapotransporation. This has benefited the parking space both functionally and aesthetically.
Watershed: Schuylkill River
CF Pottsgrove Associates, LP
Total cost: $315,000
Wet pond, pump and aerators: $200,000 (estimate)
Roof: $60,000 (estimate)
Channels: $5,000 (estimate)
Parking: $50,000 (estimate)
Nicholas P. Rakowski, PE
357 South Gulph Road, Suite 300
King of Prussia, PA 19406