By Shannon Madden
We were excited to hear – and report back to our WOWW readers – two very different stories of stormwater management in northeast Illinois at the Illinois Section American Water Works Association’s WATERCON conference in March. A side-by-side look at these two stories of local stormwater management shows how green infrastructure can address concerns about flooding and water quality simultaneously.
Hinsdale: Volume control to reduce urban flooding
As the Village of Hinsdale adds more (and larger) homes and streets, there is less open space to naturally manage rainwater. Inefficient drainage has led to local flooding – a messy and costly nuisance.
When stormwater exceeds sewer capacity, it can damage property by backing up into basements. (Photo courtesy of Andrew Bisdale)
After a 2008 Drainage Investigation estimated that building larger storm sewers and underground storage basins would cost $25 million, the Village began seeking a more economically viable solution. Hinsdale hired consultants to conduct a Green Initiatives Feasibility Study, which found that the Village could achieve similar stormwater benefits by including rain gardens and bioswales along public rights of way – all for about $10 million less than the 2008 estimate.
With this financial incentive, the Village held public meetings and provided brochures to explain the green infrastructure plan. Residents asked tough questions but supported the project overall. Public coordination helped ensure that sensitive local issues, like maintaining neighborhood character and protecting trees, were included in the planning process. After the bioswales, rain gardens and other green infrastructure are in place this summer, the community hopes localized flooding is less of a problem. See HR Green and the Village of Hinsdale’s presentation for more information.
As with the Milwaukee Avenue Green Development Corridor program – a green infrastructure grant program the Metropolitan Planning Council (MPC) is piloting in Chicago’s Logan Square neighborhood – Hinsdale’s use of green infrastructure shows how residents, public leaders and consultants can work together to respect community finances and values when selecting stormwater management practices that ease urban flooding.
Rainbow Beach: Water quality improvements to address public health concerns
While Hinsdale targets stormwater volume, researchers at the Illinois Institute of Technology (IIT) have a different goal for Rainbow Beach, a popular destination at 77th Street on Chicago’s southeast side. Due to excess E. coli, which can cause diarrhea and other health problems, Rainbow Beach was closed 123 days between 2006 and 2011; that’s the second-highest number of closures of all Chicago beaches. When stormwater runs over the lakeside parking lot – which is often crowded with pigeons – it collects E. coli, metals and other pollutants that diminish water quality. As Natural Resources Defense Council’s Laurel O’Sullivan told the Chicago Tribune, “Stormwater runoff is the No. 1 reason for beach closings.”
Rainwater carries contaminants from the parking lots near Rainbow Beach directly into Lake Michigan. This diminishes near-shore water quality and often forces the Chicago Park District to restrict swimming at the beach. (Photo courtesy of Giri Prabhukumar)
With funding from the Great Lakes Restoration Initiative, IIT Professor Krishna Pagilla and Ph.D. candidate Giri Prabhukumar aim to improve near-shore health by filtering runoff before it reaches Lake Michigan. Lab tests have helped the researchers refine their multimedia filter, with contents like iron filings and biochar, to effectively improve stormwater quality. Partnering with the Chicago Park District, which also monitors water quality through the Beach Ambassador program, Pagilla and Prabhukumar plan to construct the filter this year, establish a long-term maintenance plan and monitor water quality and flow at Rainbow Beach to evaluate filter success. The researchers are optimistic that the filter’s water quality improvements will keep the beach swimmable more often. See Mr. Prabhukumar’s presentation to WATERCON here.
The Village of Lake Zurich – a community in Lake County that MPC is providing technical assistance to on water planning – has a similar interest in improving water quality. Like stormwater running untreated into Lake Michigan from Rainbow Beach, runoff from Lake Zurich’s downtown can diminish the quality of the Village’s namesake lake. As the Village encourages downtown redevelopment, it also wants to improve the quality of water that enters the lake. Integrated water resource planning – or considering water supply, wastewater, stormwater and water quality all together – will help the Village pursue comprehensive plans to reduce localized flooding, protect the lake’s water quality and reduce the downstream cost of water treatment.
Integrating volume and quality control objectives
While a stormwater project might focus primarily on volume or water quality, the truth is that green infrastructure can address both.
For example, Hinsdale’s volume-control strategy provides water quality benefits as well: the planned bioswales and rain gardens will remove excess nutrients, filter out solids and remove other urban pollutants from stormwater. Similarly, if IIT’s new technology successfully improves water quality, it could be combined with other green infrastructure to reduce runoff volume as well.
These dual benefits of green infrastructure might be particularly helpful in a place like Blue Island, Ill., a south suburb of Chicago working with MPC to reduce neighborhood flooding and improve the Cal-Sag Channel for use as a recreational destination. Mimicking natural hydrology with green infrastructure, and doing so in a data-driven manner, can be part of a cost-effective strategy to mitigate urban flooding, improve water quality and use our natural assets wisely in Blue Island and elsewhere. From every angle – public health, aesthetics, economics and sustainability – purposeful green infrastructure works alongside existing infrastructure to improve everyone’s experience, one project at a time.
To find out what else we learned at the conference – and what MPC shared about our own work with the Northwest Water Planning Alliance and Lake Zurich – visit the conference website and download presentations.
