How an old corporate HQ became a natural habitat and solved a flooding problem in Mundelein
One particularly beautiful morning last week, Mundelein Mayor Steve Lentz strolled along the paved path near the stormwater detention pond on Courtland Street near Seymour Avenue.
Out among the tall prairie grasses, wildflowers and other vegetation, animals were busy.
A family of ducks paddled across an open patch of pond, creating a small wake. Canada geese swooped down for a water landing, perhaps in search of insects or fish to eat. On the shore, white butterflies flittered between bright-yellow flowers.
Remarkably, less than two years ago, none of this existed here.
The roughly 8-acre pond was created by the village as part of a nearly $9.2 million flood-control project. It's designed to collect water during large storms and slowly drain afterward.
The dilapidated former headquarters of U.S. Music Corp. was torn down to make room for the pond.
Since the site's completion last September, it has become a diverse ecosystem with abundant vegetation and a bounty of insects, mammals, birds and other creatures.
“It's like terraforming a planet,” Lentz said.
A history of flooding
The project was developed after a July 2017 rainstorm caused a hydrological disaster in town. The Western Slope neighborhood, which is on the west side of Route 45 near Division Street, not far from where the pond is now, was hit especially hard.
Streets, yards and many homes were flooded, and not for the first time. The Seavey drainage ditch, a man-made channel that flows through that part of Mundelein to Indian Creek and the Des Plaines River and is supposed to alleviate flooding, had once again failed to do its job.
After angry Western Slope residents demanded village leaders fix the recurring problem, officials hired the McHenry-based engineering firm HR Green to determine why the neighborhood has flooded so often.
HR Green discovered Mundelein's stormwater system wasn't big enough to handle heavy storms like the one that summer. The firm also found rainwater had been entering the town's sanitary sewers through cracks in pipes and improper hookups, which caused sewage backups in some houses.
The village worked with HR Green and other firms to install nearly a mile of new sewer pipes under Division Street. Culverts on Route 45 and Seymour Avenue were replaced, too.
The village also acquired and demolished the former U.S. Music building and created the stormwater basin there, alongside a stretch of the Seavy ditch.
Basin is thriving
With most of the improvements underground, the detention pond — technically, a naturalized detention basin — now is the most visible aspect of that massive flood mitigation project.
Such basins are loaded with vegetation to provide greater water quality and more beneficial habitats than traditional detention basins, according to Lake County's Stormwater Management Commission.
The site is divided into different habitats with different types of vegetation.
Mundelein's basin was seeded so plants native to the region would grow. But since the resulting vegetation will take two to three years to reach maturity, more than 6,400 perennials were planted around the perimeter to jump-start the ecological redevelopment.
Big bluestem, little bluestem, New England aster, purple prairie clover, spiderwort and golden Alexander are just some of the many vegetative species either planted or seeded in or around the pond.
“The wet prairie species within the basin bottom have really taken off,” said HR Green's Logan Gilbertsen, the lead engineer on the pond project. “The most prevalent ones were bur-reed and river bulrush, last time I visited the site. Along the side slopes, the black-eyed Susan is already blooming, and some of the other forbs are starting to bloom.”
Lentz admitted being surprised by the breadth of prairie life on the site. Initial talks included a butterfly sanctuary, he recalled — but nothing on this scale.
“It's awesome,” Lentz said.
The array of vegetation attracts animals seeking shelter and food.
Egrets and heron have been seen hunting frogs, insects and minnows in the basin, Gilbertsen said. Additionally, red-tailed hawks, owls and other winged predators visit the area frequently, he said. Bluebirds, finches and other seed-loving birds are common, too.
“Streams and rivers are like highways for wildlife,” Gilbertsen said. “Since this basin is right next to a regional waterway, there were already many species of birds, reptiles, amphibians and insects in the area.”
The plants also soak up nutrients that otherwise could harm aquatic life, Gilbertsen said.
On the same day Lentz took in the view at the basin, Mundelein resident Mary Maillard and her husband, Jerry, walked past the pond as part of their exercise route. The wetlands are much more attractive than the abandoned factory that once stood there, the couple agreed.
“There's herons, there's cranes — it's fun to watch them,” Mary Maillard said.
'It all worked'
Of course, as entertaining as the site may be for passersby, the basin primarily was created to reduce flooding.
Thus far, it's been successful.
During a storm in late July that dumped nearly 5 inches of water on Mundelein in about six hours, no flooding was reported. Previously, standing water would fill Western Slope's streets and be up to people's yards after a storm like that, Lentz said.
“It all worked,” he said. “It's just wonderful to see.”
Gilbertsen celebrated the lack of flooding after last month's storm, too.
“We would say that is a big win,” he said.
Mundelein's new prairie
A man-made prairie that was designed to be a stormwater detention basin is thriving in Mundelein. Here's a look at the project ... by the numbers.
2017: The year of the catastrophic flood that prompted officials to create the basin
8.1: In acres, the estimated area of the basin.
40: In acre feet, the amount of stormwater the basin can hold.
6,424: Plant plugs installed within the basin
$9.16 million: Total cost of the flood-control project, including the basin, new sewers and more.
0: The number of flooding complaints in the village after a particularly heavy rainstorm last month. Officials credit this project.
Source: village of Mundelein