Waubonsee Community College

Project Description: Waubonsee Community College needed to expand its student and staff parking lots to create additional spaces for its increasing enrollment. As construction would disturb land area, the college needed to manage the stormwater runoff on site. Per Waubonsee Community College’s request, permeable pavers were used in the parking lots, as opposed to traditional black top methods, and biofiltration strips were utilized in the middle of the parking lots to help improve water quality. To work with the permeable pavers and manage stormwater, StormTrap’s SingleTrap stormwater infiltration systems were chosen for the east and north parking lots on campus.

Challenges: The StormTrap team and the engineers had to determine how to best integrate the permeable pavers with the infiltration system without compromising on water quality or total open void space. It also had to be determined how water that did not infiltrate the system through the permeable pavers would enter the infiltration system.

Solutions: The StormTrap system was split into two different basins underneath the east and north parking lots on the campus. Both of the systems were set on a stone base, and in order to easily incorporate the permeable pavers, the StormTrap precast concrete units had a ½” – ¼” gap between them to allow the water to enter the system after passing through the pavers. To protect water quality, a geotextile filter fabric was placed on top of both systems to prevent silt and sediment from entering. The stormwater runoff that does not infiltrate through the pavers is collected in the bioswales in the parking lots, which are tied to the StormTrap systems by catch basins. The StormTrap system provided the College an infiltration solution that allowed them to easily integrate permeable pavers while still meeting the stormwater management requirements for the site and not compromising on water quality.