Green Stormwater Infrastructure and Public Health

From the puddles you avoid on the sidewalk to the water slowly rising on your basement floor—or the flash flooding in many parts of Chicago—the effects of wet weather reach all of us in one way or another. Those who work in the stormwater sectorare acutely aware of how water, whether wanted or unwanted, affects both infrastructure and public health.

Stormwater is the term we use for rain once it lands on impervious surfaces.

Before urban development, rain would soak into the ground where it landed.  Now, it typically flows across these impervious surfaces, picking up trash, oils, chemicals and other pollutants, eventually ending up in local rivers, streams and other waterways.

Historically, the mindset for managing stormwater was to convey water away from where it lands as fast as possible using pipes—what is known as “grey infrastructure.” However, depending on if your community has a combined or separated sewer system, this approach can have unintended consequences. Combined systems, like we have in Chicago and other older municipalities in the region, can become overloaded, leading to basement backups and contributing to flash flooding.

Stormwater is a resource that can benefit public health and resilience.

This shift of thinking is difficult, in part because we tend to notice stormwater only when it becomes a problem. For example, when storms overwhelm combined systems, untreated stormwater and wastewater can contaminate nearby waterbodies, back up into basements, or in extreme cases, result in fatalities. In Chicago, the combined sewer system can become overwhelmed in this manner, resulting in flooding that disproportionally impacts lower-income and minority communities, as MPC described in an article about our stormwater management project.

To embrace stormwater as a resource, we need to recognize that natural processes to slow, store and treat stormwater were here before development. These natural systems are what we should look to for guidance.

How GSI strengthens public health.

If you are connected to sustainable urban development, you may already be aware of the basics of green stormwater infrastructure, the main goal of which is to slow down and soak up stormwater by mimicking “natural ecosystems and cycles.”

What makes GSI unique is its muti-benefit nature, which allows it to create value across various sectors, from public health to transportation to economic development and beyond. Specifically for the public, the connection to health comes in both reducing the heat island effect and improving air quality.

In the report, Green Values Strategy Guide: Linking Green Infrastructure Benefits to Community Priorities published in 2020, The Center for Neighborhood Technology (CNT) found that vegetated GSI infrastructure can combat the heat caused by our increased use of impermeable surfaces, “by providing direct shade and cooling the air through evapotranspiration,” reporting that, “shaded surfaces can be 20° to 45°F cooler than unshaded surfaces during peak summer temperatures.” and “evaporation can reduce peak temperatures by 2° to 9°F.”

The report noted that the plants that create shade also “improve outdoor air quality by absorbing pollutants into the plants.” This matters because “Particulate matter is ranked first among nine environmental risk factors with the highest health impact” and “exposure to high levels of ozone pollution leads to increased rates of hospitalizations and emergency room visits.”

The following initiative from Chicago-based Blacks in Green™ (BIG) a program that looks at stormwater through this lens of creating value; Sustainable Square Mile.

Sustainable Square Mile: BIG developed the Sustainable Square Mile framework to build walkable, self-sustaining Black communities rooted in environmental stewardship and economic resilience. Guided by the 8 Principles of Green Village Building, BIG promotes neighborhood-scale systems where local wealth, green jobs, and climate adaptation intersect.

In West Woodlawn, BIG’s Botanic Garden & Village Farm Initiative exemplifies how vacant land can be transformed into productive community assets. Through practices like rain gardens, permeable paving, and local food systems, the initiative integrates GSI into broader homesteading and land stewardship goals. These nature-based solutions reduce localized flooding while fostering job creation, improving public health, and reinforcing cultural heritage.

Co-benefits of Green Stormwater Infrastructure can be quantified.

The next big question is: how to quantify the benefits of GSI to guide future decision making. MPC’s current project, Right Infrastructure, Right Place, is tackling this challenge by developing a data-driven tool that will provide some of these answers. This tool will quantify co-benefits such as:

• Cost savings from avoided stormwater treatment or grey infrastructure upgrades
• Community Health savings from reduced heat stress and cleaner air
• Economic gains from increased recreation access an enhanced biodiversity

From sidewalks to basements, stormwater touches us all. GSI reframes these challenges as opportunities, delivering cleaner air, safer streets, and stronger public health alongside resilient infrastructure. By pairing strategic investment in green infrastructure nature-based solutions with essential grey infrastructure improvements, communities can become more resilient by reducing the risk of flooding, improving water quality and fostering social, economic and environmental benefits.