Green Roofs Help Combat Environmental Issues and Reduce Stormwater Runoff

Retail Client

Chicago, IL | Retail | Stormwater Maintenance


A customer site in Chicago, IL aims to better the lives of its customers by providing quality products for reasonable prices. Their environmental goals of reducing stormwater runoff and supporting biodiversity are demonstrated in their commitment to utilizing green infrastructure.


This client, located in Chicago, required a cost-effective way to manage stormwater runoff. In most urban areas, stormwater runoff is a major concern due to the lack of pervious surfaces that naturally absorb and filter stormwater. Stormwater runoff is one of America’s most significant water pollution contributors, with 10 trillion gallons of rainwater flowing over rooftops, roads, and parking surfaces each year. Along the way, it picks up harmful contaminants that can pollute natural water bodies and the sheer volume of stormwater can overload sewage systems. In addition to the issue of stormwater runoff, Chicago, like many other urban areas, also experiences an urban heat island effect. The sun’s energy is absorbed by buildings and man-made surfaces, which causes ambient temperatures in cities to be higher than in surrounding rural areas. Lastly, with much of urban areas being dominated by non-natural features, habitat for many insect populations is dwindling. The resulting decline in insects is of significant concern because some species play a critical role in the pollination of plants. One out of every three bites of food we consume were pollinated by insects.

With this client, AQUALIS has helped maintain a green infrastructure asset aimed at reducing stormwater runoff and was also able to provide a solution that contributed to the betterment of environmental issues such as the urban heat island effect and loss of biodiversity.


Insect sample collected from traditional non-vegetated roof.


Insect sample collected from within a pollinator garden on a green roof.


The client established an extensive green roof on their building at the time of construction. AQUALIS provides regular inspection and maintenance services to the roof and recently completed a retrofit that involved incorporating specific types of plants that provide habitat for pollinator insects. During the summer, green roofs can retain 70-90% of rainwater and slow the flow of excess stormwater runoff which decreases stress on sewer systems. Not only do these roofs resolve stormwater runoff issues but they also moderate the urban heat island effect. Green roofs are covered with plants that produce dew and maintain evaporation cycles that help lower local ambient temperatures.

Through the retrofit project, AQUALIS provided research opportunities for college student interns. In 2020, interns planted a pollinator garden on the green roof and monitored subsequent use of this area by insects to determine if this green infrastructure asset would support natural biodiversity. The interns found that insects did use the garden more frequently than an area of traditional green roof vegetation and an area of the non-vegetated bare roof. This finding suggests that green roofs can not only solve stormwater management issues but they also can support an increase of biodiversity within urbanized areas. AQUALIS is proud to offer comprehensive water management services to our clients including options for green infrastructure that impact not only stormwater but the environment. You can learn more about AQUALIS’ Roots for Nature, pollinator garden program by clicking here. Ask your AQUALIS representative if adding a pollinator garden to your green roof, swale, or detention basin.


About Green Roofs. (n.d.). Retrieved August 23, 2020, from green-roofs
Bauer, K. (2019, May 09). Fireflies, Monarch Butterflies Are Dying Off In Chicago Due To Climate Change, Expert Says. Retrieved August 23, 2020, from chicago-due-to-climate-change/
Rosenberg-Douglas, K. (2019, July 18). What you need to know about Chicago’s urban heat island ahead of ‘oppressive’ hot weather stint. Retrieved August 23, 2020, from island-20190718-kv7paijixzhf5ioknodfgdhlwy-story.html

Download the case study here

Download PDF