Dec 12, 2016

Blue Island Green Infrastructure Project

When the city of Blue Island, Ill., sought to reduce basement flooding for its residents, Environmental Design Intl. Inc. understood finding the right plots for rain gardens and green infrastructure would be crucial.

At $663,000 and 15,720 sq ft—covering approximately 16 blocks—the project was one of the largest Environmental Design Intl. had done. Searching that area to find the most suitable properties was the most work-intensive part of the project. The lots could not have utilities that would disrupt or delay construction, and properties with basements were eliminated. More space in the ground meant more storage capacity for infiltrated storm water.

The list of potential sites was slimmed down even further. Streets with traffic moving east and west were too narrow and greatly sloped, so the project targeted homes on north- and southbound streets instead.

“Another interesting part of the selection process was that we needed to find parkways that were relatively wide … so that we could maximize the effectiveness of the rain garden,” said Carl Bova, engineer for Environmental Design Intl. That same principle was applied to sites with similar characteristics during the sorting process, and those with a greater potential for infiltration were selected.

Safety was also of concern. Rain gardens were strategically placed so as not to impede the vision of drivers on roadways. Bova said they used a 2-ft setback when determining where to place the plants, which were a mixture of local species.

To help prevent homeowners or maintenance workers destroying the flora, the city held informational meetings about the plants’ importance. The plants also provided a pleasing aesthetic, and Bova said homeowners have been happy with the results.

In fact, homeowner satisfaction was a priority throughout the construction process.

“We didn’t want to become an encumbrance to the homeowners, so as a result, we made sure we kept the 2-ft buffer, the grass strip, that was at about the same grade as the sidewalk, so that if the person should leave the sidewalk, they don’t trip and fall,” Bova said.

Project Year:
Designers: Environmental Design Intl. Inc.
Owner: Metropolitan Water District of Greater Chicago
Location: Blue Island, Ill.
Cost: $663,000
Size: 15,720 sq ft