Loyola’s green roofs and rain gardens reap massive environmental dividends

At her home on Chicago’s north side, Karen Weigert has a green roof that sprouts native prairie plants: Little bluestem, purple coneflower, butterfly weed. It’s a lovely oasis, and it’s also environmentally friendly—cooling the surroundings, soaking up stormwater, and attracting birds, butterflies, and other pollinators.   

Of course, Weigert doesn’t need to stay at home to enjoy the benefits of natural landscapes. As the director of the Baumhart Center for Social Enterprise and Responsibility at Loyola University Chicago’s Quinlan School of Business, she can gaze out the south-facing glass facade of the Schreiber Center at a green roof atop Maguire Hall, one of 17 that span more than 55,000 square feet on the Lake Shore and Water Tower campuses, comprising the largest green roof acreage of any Midwest campus.   

Carpeted with richly colored, low-growing, leaf succulents known as sedums, the ecologically friendly green roofs are just one part of Loyola’s broader green infrastructure network, which includes rain gardens, semi-permeable walkways and plazas, stormwater infiltration vaults, and a diverse collection of deep-rooted, sponge-like native plants.  

Collectively, the network diverts an estimated 19 million gallons of water from city sewers annually—enough to connect Chicago to Houston with one-gallon water jugs—and it is supported by a smart irrigation system that waters plants in response to localized weather station data, reducing campus water use by 30 percent. 

“The fact that Loyola has been leader in environmental stewardship and is hard at work creating a sustainable campus and reducing its carbon footprint is absolutely the reason I joined,” Weigert, who was hired in 2022, told Loyola Today.    

That’s an especially strong endorsement coming from Weigert, a former Goldman Sachs investment banker who served as the first-ever chief sustainability officer for the City of Chicago, helped write and produce the acclaimed documentary film Carbon Nation, and is a regular sustainability contributor for WBEZ’s daily talk show, Reset.  

And she is hardly the only one prizing the University’s commitment to sustainability. Loyola recently ranked 12th in The Princeton Review’s “Guide to Green Colleges: 2025 Edition,” making it the highest-ranked Jesuit institution and the top school in Illinois on the list.  

 A national model of carbon reduction and climate resiliency  

The accolades stem, in part, from Loyola’s robust Climate Action Plan for reducing carbon emissions, which along with a $150 million investment in high-performing buildings and renewable energy systems, set the stage for Loyola to attain carbon neutrality on its Chicago-area campuses in December 2024, becoming the first Chicago university to do so.   

Guided by the expertise of staff in the Office of Sustainability and faculty in School of Environmental Sustainability, Loyola’s progress toward net-zero emissions has been marked by important milestones, including an agreement with Swift Current Energy to purchase renewable energy credits from the Double Black Diamond solar farm in Central Illinois. Enrollment growth and curricular expansion of the Institute of Environmental Sustainability, which became the School of Environmental Sustainability in 2020, helped propel these efforts. 

All these accomplishments are notable, but as an urban campus bordering Lake Michigan and relying on Chicago’s sewer system for a portion of its stormwater diversion, Loyola’s commitment to onsite, plant-based approaches to water capture and treatment may be among its best kept secrets, says Kana Henning, vice president for Facilities and Campus Management.  

The tall native grasses and flowering perennials found in raingardens north of the Sullivan Center and south of Madonna della Strada Chapel are adapted to moist soil; require no irrigation and only minor maintenance; and act like a self-cleansing sponge, filtering out contaminants from stormwater runoff before it drains into Lake Michigan.   

 “The rain gardens help manage natural runoff, both through their topography and the plant material you find within these locations,” Henning said. “Since the plants are native to the environment, they’re hardier and more resilient to Chicago’s climate.”    

As a building design requirement for all Loyola’s new campus buildings, green roofs not only help soak up rainwater and reduce flooding; they also help to curb the urban heat island effect by cooling the air through evapotranspiration.  

The long-term results of Loyola’s campus greening efforts, begun as part of the 2010 Reimagine Campaign to update the campus, speak for themselves. In 2003, 95 percent of Loyola’s Lake Shore campus discharged stormwater to city sewers. Today, that number is down to 37 percent, and green roofs and raingardens conceived in partnership with the Chicago architecture firm SmithGroup, deserve a large share of the credit.   

 Hamlet Gonzalez, a business manager for Facilities and Campus Management, acknowledges that native landscaping is not ideal everywhere. But even on expansive turf lawns designed to support social gathering and large events, such the West Quad, the land’s topography is intentionally designed to convey stormwater into underground cisterns, where it is filtered and treated before being drained into Lake Michigan.  

This cleverly engineered system, Gonzalez says, not only protects the water quality of the lake, it also keeps stormwater out of the city’s overburdened sewers and treatment plants and reduces the risk of flooding in surrounding neighborhoods.  

 “It really creates a pressure relief valve for the city’s infrastructure and helps us [as residents] because it saves our basements from being flooded,” Gonzalez says. 

Inspiration for Chicago-area homeowners and renters   

Apart from adding beauty to campus and providing ecological benefits, Loyola’s natural landscapes offer inspiration for residents looking to introduce environmentally sensitive greenspace at a smaller scale, Weigert says. For some, that might mean installing a green roof above a detached garage. Others might consider replacing portions of their rear lawns with native plant beds. 

Even small changes can have a profound environmental impact. Native plants that meet the USDA Plant Hardiness Zone classification for the area—zone 6a for Chicago— can substantially reduce the need for irrigation. By replacing turf lawns, they can also eliminate the carbon impact of gas-powered mowing, which the U.S. Environmental Protection Agency estimates makes up 5 percent of the country’s air pollution.     

But the most salient benefit to planting ecologically friendly landscapes may be that they provide nesting and foraging habitat for wildlife, helping people who steward them feel invested in an ecological cause larger than themselves.  

“We know monarchs are migrating thousand and thousands of miles, so if you provide habitat for them you play a part in that. It’s not just what the landscape looks like; it’s really about connection to global stewardship and opportunities to be a part of the future that we all want, need, and deserve,” Weigert said.