Jen Jenkins surveys the terrain of Sundrop Prairie (Sarah Anderson/MEDILL).
Environmental engineering duo explore natural solution to flooding south of Chicago
Colleen O’Brien and Jen Jenkins battle through unruly, waist-high foliage, dodging the thorny plants that grab at their clothes. In the sweltering July heat, their work space is a far cry from the air-conditioned office buildings they used to frequent. They forge ahead, drawn to Sundrop Prairie by a desire to integrate a community component into a technical industry.
“I think what I didn’t have in my last role was being able to engage with people,” Jenkins said, reflecting on her transition from an environmental consulting firm. O’Brien, also a former consultant, echoed this sentiment. “I loved that there was a community partner aspect to the work,” she said.
Jenkins now works as a natural infrastructure project manager at The Nature Conservancy, and O’Brien is a Ph.D. candidate in the Department of Civil and Environmental Engineering at Northwestern University. They are partnering together to study the hydrology of the Indian Boundary Prairies, a cluster of five grassland regions that form a rare natural oasis just south of Chicago.
The Nature Conservancy’s work focuses on maintaining the prairies as a natural habitat for biodiverse species, with big bluestem, little bluestem and Indian grass attracting monarch butterflies and various migratory birds. But the prairie edges—where tar and asphalt were dumped during the construction of the road that continues to leach metal and salt into the soil—may be beyond restoration. Jenkins and O’Brien are exploring if the prairie boundary could be dedicated as a space for stormwater collection to help mitigate flooding in the region.
To evaluate Sundrop Prairie’s water storage capacity, the pair collect data from wells installed throughout the prairie. A sensor in the well reads the underground water level, which indicates how much water is absorbed by the prairie that would otherwise be displaced. “It basically tells us, ‘If the prairie wasn’t here, how much water would be in someone’s backyard or on the street?” O’Brien said.
This data also gives them an idea of how much more water the prairie might be able to take on. “What we need to do is get the prairie to work even harder than it already is,” Jenkins said.
O’Brien and Jenkins also analyze the water’s conductivity, which serves as a measure of how much salt and metal is in the water from contact with surrounding roads and industry. The conductivity trends allow them to see how far into the prairie interior this “urban runoff” effect persists, which can help to identify areas of the prairie that are connected by water flow paths.
Understanding how the waterways intersect is critical in determining if diverting stormwater to the periphery could distress the prairie as a whole. “If we are going to think about ways to encourage more or less stormwater onto the site, we have to think about any unintentional negative impacts on the rest of the prairie,” Jenkins said.
The team also takes this holistic approach when considering how to maximize the benefit of the prairies for the local community. “We’re not just looking at the prairies in isolation—it’s all in the context of what’s happening around us,” Jenkins said.
To learn about the needs of their neighbors, O’Brien and Jenkins are developing a survey for south suburban residents on their experiences and perceptions related to flooding. In addition to informing their work, the responses help them to gauge people’s understanding of stormwater management and ensure that their communication with the public is accessible.
Jenkins and O’Brien hope that through a combination of innovative environmental engineering and dialogue with the community, they can help to combat the flooding that disproportionately impacts the area south of Chicago. “This problem, it’s not just a nuisance, it’s a public health problem,” Jenkins said. “When you understand that these residents are affected by flooding on a regular basis, you can’t help but be moved to try to figure out a solution.”