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Green Stormwater Infrastructure Helps Curb Effects of Climate Change in Cities

Chicago's Space to Grow program builds schoolyards with native vegetation and permeable surfaces that capture stormwater. | Dan Wendt/Metropolitan Water Reclamation District of Greater Chicago

During a recent webinar co-hosted by the American Association for the Advancement of Science, representatives of five city, county and regional water systems across the United States discussed strategies for implementing environmentally conscious and climate-resilient stormwater infrastructure.

The panelists provided valuable insight to an audience of 300 local water leaders on how to defend municipalities against pollution, flooding and other issues associated with extreme precipitation events, which are becoming more frequent as the planet warms.

In contrast to the complex network of piping, sewers and other collection systems known as gray stormwater infrastructure, green stormwater infrastructure treats precipitation at its source. Methods including restoring patches of natural vegetation, laying permeable pavements and installing green roofs allow more rain to filter locally, reducing runoff that can carry pollutants into public waterways and cause devastating urban floods.

Intense storms that test the limits of gray infrastructure are on the rise. A 2019 study, published in Scientific Reports by an international team of climate researchers, showed that the total precipitation from extreme events almost doubles with each degree of warming.

Recognizing the topic’s urgency, the AAAS Center for Scientific Evidence in Public Issues, known as the EPI Center, organized the Aug. 13 webinar in partnership with WaterNow Alliance, a nonprofit that advocates for sustainable water policies at the state and federal level, provides a grassroots forum for its members to exchange ideas, and supports the development of green initiatives in their communities.

Since its launch in September 2018, the EPI Center has worked to deliver clear, concise and actionable scientific evidence to elected officials and others involved in shaping policy. In addition to green stormwater infrastructure, its current focus areas include voting security, hydraulic fracturing, racial bias in policing, and PFAS, a family of synthetic chemicals linked to numerous diseases and found in the blood of nearly all Americans.

“We want scientific evidence to be part of the decision-making process, so we’re working to make it easier for policymakers and decision-makers to access scientific information,” said Rebecca Aicher, an EPI Center project director.

Among the experts presenting during the webinar were Jessica Brooks, director of the Philadelphia Water Department’s green stormwater infrastructure unit, and Corey O’Connor, chair of the Allegheny County Sanitary Authority (ALCOSAN), the sewer system for Pittsburgh and 82 surrounding municipalities. Both discussed their organizations’ move away from gray construction in the past decade.

“A couple years ago, we did not really have a green-first approach, which we were able to change,” O’Connor said. “We now have what’s called the GROW program, where municipalities come to ALCOSAN, and we match their grant funds to do green infrastructure projects.”

Since 2016, the GROW program has provided more than $30 million toward sustainable projects, with the funds often covering engineering costs that smaller municipalities would otherwise not be able to afford. O’Connor also highlighted a new initiative in Pittsburgh to train workers in the construction and maintenance of green infrastructure.

“It’s really important that we look at green infrastructure not only to get out of our [gray] system, but also to create new jobs and to create a different type of wealth in our region,” he said.


Farnsworth Elementary School in Chicago before and after its green renovation. | Dan Wendt/Metropolitan Water Reclamation District of Greater Chicago

Tyler Antrup, director of planning and strategy at the Sewerage and Water Board of New Orleans, laid out the unique challenges of managing stormwater in a city that is approximately 50% below sea level and, with 64 inches of rain each year, one of the wettest cities in North America. James MacAdam, Tucson Water’s superintendent of public information and conservation, focused on the importance of replenishing groundwater in a city at the other end of the spectrum, receiving only about 12 inches of rain per year.

“Most people know green infrastructure in our town as rainwater harvesting,” MacAdam said. “For us, rainwater harvesting isn’t just capturing it in tanks, it’s capturing it in the ground.”

Kimberly Du Buclet, a commissioner of the Metropolitan Water Reclamation District (MWRD) of Greater Chicago, presented on the success of the Space to Grow program, a partnership between MWRD, the Chicago Department of Water Management, Chicago Public Schools, and local nonprofits. To date, Space to Grow has built 34 playgrounds in the city that together capture more than 5 million gallons of water per storm event.

During a Q&A session following the presentation, a viewer asked if any of the panelists had run into challenges related to interest groups or other community members opposing their green initiatives.

“We don’t have any objections,” Du Buclet said of her experience rolling out Space to Grow. “Our biggest issue is the competition from the communities and schools that want the project.”