Taggreen streets

Readers Ask: Recommending bioswales

The second post in “Readers Ask,” from a planning student in Chicago.

I want to recommend bioswales for my Complete Streets project area which consists of a part of Grand in Chicago, Illinois  There are a lot of surface parking lots over there, and a big shopping mall which is built on a weird arrangement of slopes (Brickyard).  Since I know nothing about bioswales, I’m wondering what you could tell me about how I could go about recommending this. I have no idea what the rainwater runoff issue is over there, but I could only imagine that there would be one, with all the surface parking and weird slopage.

Bioswales are just one of many solutions to water runoff and stormwater collection. Another option is using permeable pavers in the parking lot. The real experts on this are Janet Attarian and David Leopold at CDOT. As a project manager at the Streetscape and Sustainable Design Program, he’s dealt with and implemented bioswales, permeable parking lots, and pollution fighting bike lanes – the works. There’s a parking lot, designed by CDOT, built with a bioswale AND permeable pavement on Desplaines between Polk and Taylor in Chicago (photo below)/

Parking lot has permeable pavement and a bioswale. The site is monitored by CDOT to see how it performs in the winter. Photo by Bryce.

EVERY parking lot has runoff – every parking lot should do a better job managing it. By not better managing our stormwater, we all pay the costs, be it through flood insurance, recovering from floods, or having to build bigger pumps and sewers.

Permeable pavement at Benito Juarez High School in Chicago, Illinois.

Perhaps you shouldn’t recommend a bioswale, but a parking lot that “captures 80% of its runoff” or something through a “variety of methods.”

Bioswale in Portland, Oregon, as part of a green street transformation.

The EPA lists additional Best Management Practices. The Cities of  Seattle and Portland are experts in this. Portland was even able to get parts of its bikeway built by rolling them into the Department of Environment’s Green Streets program, their efforts to reduce stormwater runoff and thus reduce the costs they pass on to their customers that pay for sewer service (like, everyone). I recommend this blog article about Portland’s sustainable design, written by a fellow planning student.

Philadelphia Water Department moves away from Deep Tunnel-style water management

West North points out that instead of spending $8 billion to build new sewage holding tanks throughout the city, the Philadelphia Water Department plans to conver impervious surfaces to pervious, natural surfaces. The American Society of Landscape Architects has more information on The Dirt:

The green infrastructure proposal would turn 1/3 of the city’s impervious asphalt surface, or 4,000 acres, into absorptive green spaces. The goal is to move from grey to green infrastructure. Grey infrastructure includes “man-made single purpose systems.” Green infrastructure is defined as “man-made structures that mimic natural systems.” As an example, networks of man-made wetlands, restored flood plains, or infiltration basins would all qualify as green infrastructure. The benefits of such systems include: evaporation, transpiration, enhanced water quality, reduced erosion / sedimentation, and restoration. Some grey / green infrastructure feature integrated systems that create hybrid detention ponds or holding tanks, which are designed to slow water’s release into stormwater management systems.

And, like Portland, Philadelphia is accomplishing more than just better stormwater management.

…the city is calling for a triple-bottom line approach, aiming for: more green spaces, improved public health, and more green jobs. [The Dirt]

Portland is building “Green Streets” that combine bicycle facilities with green infrastructure like bioswales inside curb extensions. This plan did not arise perhaps as altruistically as Philly’s (actually with a little controversy), but more as a way to build bicycle facilities with bioswale funding.

Meanwhile, the Deep Tunnel system in Chicago continues to expand. But it’s not all bad. The City of Chicago will showcase green infrastructure in a new streetscape in the Pilsen neighborhood.

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