photo J. Crocker

Chicago Mayor Richard Daly, who has already sent a successful wave of green roofs over the Windy City, has turned his sights towards his next environmental challenge: greening the city’s alleys. Some 1,900 miles of alleyways that cover over 3,500 acres of city land with paved, impermeable surfaces will become the focus of the Green Alley Project with designs and improvements to help manage stormwater, reduce urban heat island effect, promote recycling and conserve energy.

Chicago Green Alley Program, Richard Daly, CDOT, Chicago green roofs, permeable paving, best management practices, stormwater management, runoff, chicagoalley_3.jpg

The inititative is a refinement of Chicago DOT’s existing alley program which focused on creating more permeable surfaces. Chicago alleyways, which outnumber those of any other city in the world, are lacking in proper sewer connections causing serious flooding issues. Rather than simply opting for expensive sewer hookups, the city started retrofitting alleys with permeable pavements and pavers.

The Green Alley Program raises the bar with a more comprehensive strategy to implement environmentally friendly solutions to the city’s infrastructure problems. The pilot program has three main focus points which include using permeable pavements to reduce stormwater runoff, high albedo pavements to reduce urban heat island effect and using recycled material such as concrete aggregate, slag and recycled tire rubber.

The city will incorporate several techniques to improve the quality of the city’s environment. Proper grading and pitch will facilitate drainage. Dark sky-compliant light fixtures, which direct light downward, will help reduce light pollution and provide uniform illumination. Naturalized detention areas, bioswales and vegetated swales will improve stormwater management.

Neighboring property owners will also play a role in greening the city’s alleyways. The city is encouraging residents to contribute to the health of the urban ecosystem by implementing best management practices like using native landscaping, building raingardens, installing rain barrels, composting and, no surprise, considering green roofs.

+ City of Chicago Environment
+ Chicago Green Alley Handbook (PDF)
at NYT