On a particularly beautiful morning last week, Mundelein Mayor Steve Lentz strolled along the cobbled path near the stormwater retention pond on Courtland Street near Seymour Avenue.
Among the tall prairie grasses, wildflowers and other vegetation, animals were busy.
A family of ducks paddled across an open stretch of pond, creating a small wake. Canada geese rushed for a water landing, perhaps looking for insects or fish to eat. On the shore, white butterflies flitted between bright yellow flowers.
Remarkably, less than two years ago none of this existed here.
The approximately 8-acre pond was created by the village as part of a nearly $9.2 million flood control project. It is designed to collect water during heavy storms and drain slowly thereafter.
The dilapidated former headquarters of US Music Corp. was demolished to make way for the pond.
Since the site was completed last September, it has grown into a diverse ecosystem with abundant vegetation and an abundance of insects, mammals, birds and other creatures.
“It’s like terraforming a planet,” Lentz said.
A story of floods
The project was developed after a July 2017 rainstorm caused a hydrological disaster in the city. The Western Slope neighborhood, which is on the west side of Route 45 near Division Street, not far from the pond’s current location, was particularly hard hit.
Streets, courtyards and many houses have been flooded, and this is not the first time. The Seavey Drainage Ditch, a man-made channel that crosses this part of Mundelein to Indian Creek and the Des Plaines River and is supposed to mitigate flooding, had once again failed to do its job.
After angry Western Slope residents demanded village leaders fix the recurring problem, officials hired McHenry-based engineering firm HR Green to investigate why the neighborhood flooded so often.
HR Green discovered that Mundelein’s stormwater system was not big enough to handle heavy storms like the one this summer. The company also discovered that rainwater had entered the city’s sanitary sewers through cracks in the pipes and improper connections, causing sewage backups in some homes.
The village worked with HR Green and other companies to install nearly a mile of new sewer pipes under Division Street. Culverts on Route 45 and Seymour Avenue were also replaced.
The village also acquired and demolished the old US Music Building and created the Storm Basin there, along a stretch of the Seavy Ditch.
The pool is booming
Along with most of the underground improvements, the retention pond – technically, a naturalized retention pond – is now the most visible aspect of this massive flood mitigation project.
These ponds are laden with vegetation to provide better water quality and more beneficial habitats than traditional retention ponds, according to the Lake County Stormwater Commission.
The site is divided into different habitats with different types of vegetation.
The Mundelein Basin has been seeded for the native plants of the area to grow. But since the resulting vegetation will take two to three years to mature, more than 6,400 perennials have been planted around the perimeter to jump-start the green redevelopment.
Barbary bluestem, prickly bluestem, New England aster, prairie clover, spiderwort and golden Alexander are just a few of the many vegetative species planted or sown in or around the pond .
“Wet meadow species at the bottom of the pond have really taken off,” said Logan Gilbertsen of HR Green, lead engineer for the pond project. “The most prevalent were reed and bulrush, when I last visited the site. Along the side slopes the black-eyed Susan is already in flower and some of the other herbaceous plants are starting to flower.”
Lentz admitted to being surprised by the extent of prairie life at the site. Initial discussions included a butterfly sanctuary, he recalls – but nothing on this scale.
“It’s awesome,” Lentz said.
The diversity of vegetation attracts animals in search of shelter and food.
Egrets and herons have been seen hunting frogs, insects and minnows in the basin, Gilbertsen said. Additionally, red-tailed hawks, owls and other winged predators frequently visit the area, he said. Bluebirds, finches and other seed-loving birds are also common.
“Streams and rivers are like highways for wildlife,” Gilbertsen said. “As this basin is right next to a regional waterway, there were already many species of birds, reptiles, amphibians and insects in the area.”
Plants also absorb nutrients that could otherwise harm aquatic life, Gilbertsen said.
On the same day Lentz took in the view of the pond, 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 are herons, there are cranes – it’s fun to watch them,” said Mary Maillard.
Of course, as entertaining as the site can be for passers-by, the basin was first and foremost created to reduce flooding.
So far it’s been successful.
In 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 filled the streets of Western Slope and reached people’s yards after a storm like this, Lentz said.
“Everything worked out,” he said. “It’s just wonderful to see.”
Gilbertsen also celebrated the lack of flooding after last month’s storm.
“We would say it’s a big win,” he said.