Eco-Toupees and Plastic Alleys
Despite a major sustainability push, the city of Chicago still has a long way to go in transforming its image from a Rust Belt city to the greenest in the country.
Whether you’re coming to Greenbuild or not, you’re sure to get hit with hype about Mayor Richard Daley’s drive to make Chicago “the greenest city in America.” Chicago, understand, is great at this sort of thing. For years, the city could brag about having the world’s tallest building (Sears Tower) and the world’s busiest airport (O’Hare). Even now, the call letters of Chicago’s marquee TV and radio stations—WGN (for “World’s Greatest Newspaper”) and WLS (for “World’s Largest Store”)—reflect its penchant for hyperbole. That’s worth keeping in mind when you consider two of Daley’s most-ballyhooed green initiatives: roofs and alleys.
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The two are related, and not simply because they are part of a larger push to rebrand Chicago’s outdated Rust Belt image. Both aim to reduce the urban heat- island effect and to sop up stormwater. Which brings me to something you won’t hear from Chicago’s boosters: the fact that the city’s underground stormwater and wastewater conveyance systems are combined.
When it rains like cats and dogs in Chicago, the combined sewers overflow and release stormwater and untreated waste into the Chicago River. As the city’s own Web site acknowledges, this hurts the river’s health and habitat. The excess stormwater can even flood homeowners’ basements. The problem persists despite the presence of the so-called “Deep Tunnel,” a massive network of tunnels meant to divert the runoff and move it to surface reservoirs until water reclamation plants can sanitize it. Not only is this stormwater management system unable to handle big rainfalls, it’s enormously expensive.
“The idea is to find a lot of ways to decentralize these huge infrastructures. The green roofs and the green alleys are two significant starting pathways for doing that,” says Martin Felsen, co-director of the Archeworks design school and the co-designer of a plan for “eco-boulevards” that would divert rainwater directly to Lake Michigan.
His words—“starting pathways”—should be underscored. To be sure, Chicago is America’s undisputed leader in green roofs, with roughly 500 green roofs that are either finished or underway. These roofs cover 7 million square feet, roughly double the floor space in Sears (now Willis) Tower. None of this is accidental; the city requires new public buildings to meet basic LEED standards and private projects getting city aid are required to have green roofs as well. In short, the power of Daley’s iron fist backs up the preferences of his green thumb.
But a little perspective is in order: The planted roofs amount to less than one-tenth of one percent of Chicago’s more than half a million buildings. If you’re trying to control stormwater or achieve other benefits associated with green roofs, such as trimming building energy costs and providing wildlife habitat, size matters. For now, at least, Chicago lacks a green roof critical mass.
The design quality of the city’s green roofs also needs an upgrade. Chicago loves to project the image of lushly planted roof gardens, like the one Daley had installed atop City Hall 10 years ago. But many of the green roofs consist of little more than trays of pre-grown plants. They’re not particularly beautiful and they’re not inhabitable, either. They’re eco-toupees.
The green alley story is much the same—a mix of hype and hope. Chicago has “more miles of alleyways than any other city in the world,” Daley brags in the city’s green alley handbook. About 1,900 miles of them, in fact.
But the city’s old, impervious alleys, which were built with an inverted crown that funneled rainwater into streets and sewers, have caused flooding of their own as they aged and suffered wear and tear. In 2006, the city started rebuilding them with permeable pavement (pervious concrete/asphalt or porous pavers) and an aggregate base that directs rainwater into the soil. The cost of building a green alley is the same as (or lower than) the price tag for replacing a conventional alley and adding a sewer pipe, according to Janet Attarian, who directs the Chicago Department of Transportation’s green alley program.
So far, there are nearly 140 green alleys. The porous paver models I’ve seen deliver all the promised benefits, including reducing the urban heat-island effect with their light color. The construction also seems durable, unlike a pilot green alley that was built with an undergirding of plastic rings that dump trucks and garbage trucks ground to bits. Happily surveying the porous paver alley that replaced the failed plastic ring experiment, North Side resident Lou Nathan says: “They built this pretty good. It went down 5 feet. They got it right.”
Attarian isn’t indulging in hype when she says that the program’s impact extends beyond alleys. Indeed, Chicago is imaginatively rethinking its paved surfaces, from porous parking lots to roadside “infiltration gardens” that direct water into the ground. Even the plaza around the city’s showcase Buckingham Fountain has been redone with permeable pavers.
Yet as fascinating and forward-looking as these efforts are, it’s important to remember that the green roof and green alley programs remain in their infancy. Stripped of the hype, they are realistically viewed as impressive first steps that plant the seeds for a new, ecology-minded urban infrastructure. Daley’s decision not to seek reelection makes the next steps far from certain. It’s impossible to know whether his successor will push green roofs and green alleys with the same passion he did. “I would say they are having an impact,” Archeworks’ Felsen says of the initiatives. “I’m not sure it’s significant yet.”