In films and print, alleyways are painted as dark and dirty narrow passages where nothing but trouble awaits. But to the residents of Chicago, these small service streets are essential to the city’s urban fabric, providing access to garages and parking, and removing refuse containers from neighborhood streets and sidewalks.
In recent years, the city’s aging alleyways have been plagued by storm water drainage problems, making them prone to excessive flooding. In response to this and as part of a larger sustainable development initiative, the Chicago Department of Transportation launched the Green Alley Program to rethink the design of the city’s 1,900 miles of alleyways (more than any other city in the world), which translates into 3,500 surface acres of alleys.
The alleyways are paved with permeable concrete or porous asphalt, made of recycled materials, that allows storm water to filter into the ground instead of running off into nearby rivers and streams or draining into the overburdened sewer system. To reduce the urban heat island effect, Chicago is using light-colored pavement surfaces that reflect sunlight rather than absorbing and storing heat. And the city is installing energy-efficient light fixtures in alleys, which direct light downward, thus reducing light pollution. The redesign of the green alleys helps manage storm water, reduces heat, encourages recycling, and conserves energy.
While the Green Alley Program is spearheaded by the city, alleyway abutters have joined in to play a role in enhancing the performance of their new backyard environments. Residents are planting shade trees to reduce the amount of sunlight reflecting on the alleys; using native plants in gardens to reduce watering and fertilizing; and installing rain barrels to store rainwater collected from roofs.
Spurred by the success of Chicago—by the end of 2010, the city had installed over 100 green alleys—other cities including Los Angeles, Baltimore, and Detroit have adopted elements of the Green Alley Program.
And for those cities and towns without alleyway infrastructures, Chicago’s efforts can still be a model and inspiration for going green. Suburban and residential communities have acres of paved asphalt driveways; local governments could create tax incentives for property owners to retrofit their parking surfaces with permeable materials. Or perhaps suburban dwellers can find design inspiration from the past; historically, driveways were composed of brick or concrete runners, not whole pads of ugly black asphalt.
So whether it’s alleyways or driveways, both provide opportunities to contribute to a greener world.