Central Permit Facilities BMPs

Sustainable Green Stormwater Features

The Central Permit Facility's best management practices (BMPs) (PDF) to reduce stormwater runoff and pollution were designed and constructed for a sustainable site development. The facility is located on the watershed divide between the Bull Creek subwatershed (PDF) and the Des Plaines mainstem watershed.

Bio-Infiltration Swale
The bio-infiltration swale (PDF) along the south end of the visitor parking lot was constructed with layers of stone, amended soils and deep-rooted native plants to filter pollutants and to capture and infiltrate stormwater runoff from the lot.
Green Roof
Green Roof
The plants and soil on the green roof (PDF) absorb rainfall reducing runoff and pollutants from the roof surface. A special 8-inch deep planting mix is the base for a variety of small to large plants chosen because they adjust to large swings in temperature and are drought tolerant. 
Rain Garden
Rain Garden
Rain gardens (PDF) are shallow excavated landscape areas planted with wildflowers and other deep-rooted native plants. The three large rain gardens in front and on the east side of the building soak up rain water and runoff rather than allowing it to drain into the stormwater system and directly to the river. 
West Detention Basin
Wetland Detention Basins
Two wetland designed detention basins (PDF), one located in front of the building and one on the western edge, collect all of the runoff that has not been absorbed by the green roof, plant swales and rain gardens. 
Vegetated Swale
Native Plant Swales
All of the parking lots at this facility are surrounded and interspersed with native plant swales (PDF). These shallow excavated swales with deep-rooted native plants are designed to collect, absorb and filter stormwater runoff and pollutants that collect on the parking lots from automobiles.

BMP Project Cost

Funding for this BMP project provided in part by the Governor of Illinois and the Illinois Environmental Protection Agency through Section 319 of the Clean Water Act. The total project cost was $328,800, which includes the installation of the BMPs and the education and outreach program.