FloodsAs floods increase, cities like Detroit are looking to green stormwater infrastructure

By Erica Gies

Published 15 May 2019

Urban sprawl meant paving over grasslands and wetlands, making it so water is unable to soak into the ground. Today, that impervious development, coupled with the more intense storms brought by climate change, is making flooding a major issue for many cities. Urban areas are looking for better ways to manage runoff.

Detroit’s narrative over the past few decades has been grim and oft-told: auto industry abandonment, depopulation and blighted neighborhoods. But these changes have also made space for new opportunities.

One of those opportunities is around how the city develops going forward. As with many cities around the world, as it grew Detroit followed an urban sprawl model of development, paving over grasslands and wetlands, making it so water is unable to soak into the ground. Today, that impervious development, coupled with the more intense storms brought by climate change, is making flooding a major issue for many cities. Detroit is joining a growing movement worldwide to reclaim space for water in cities and implement what is known as green stormwater infrastructure (GSI) to either absorb water where it falls or to direct it in a more controlled way to treatment plants, which today can get overwhelmed by more rushing water than they are capable of handling.

At Maheras-Gentry Memorial playground, the endpoint of a road next to the Detroit River, Khalil Ligon, senior planner at Detroit’s Planning and Development Department, explains her vision for Motor City as birds call nearby. From the city’s famous 8 Mile neighborhood to this spot, Ligon envisions a corridor of parkland and porous GSI, absorbing the floods and standing water common along the route. Her vision is shared by the Detroit Water and Sewerage Department, which has built 16 GSI projects already as part of its efforts to reduce flooding and water pollution.

In the same way that solar panels on people’s roofs contribute to the electricity the city needs, rain gardens, gently sloped channels covered in water-friendly plants known as bioswales, and other GSI can absorb stormwater over a large area, reducing the need to build new treatment facilities. And unlike those concrete plants, which only provide water treatment, GSI projects deliver multiple benefits, including water storage and cleaning, wildlife habitat, neighborhood beautification and recreation space, and carbon dioxide storage to help mitigate climate chaos.

Engineered nature
The changes Detroit has experienced in recent decades have left the city with a lot of abandoned land, which makes it comparatively easy to make space for GSI. But more tightly built cities can also find a way. In fact, Detroit’s GSI program is following the lead of Philadelphia’s Green City Clean Waters, a project that began in 2011.