Tuesday evening in northeast Oak Park villagers frustrated by another round of flooding after a severe storm in June listened as two public works officials made explanation and offered the mid-term solutions Oak Park village government is working toward.
Gathered in the auditorium at Hatch School, 1000 N. Ridgeland Ave., homeowners heard from John Wielebnicki, director of public works, and Bill McKenna, the village engineer. They spent the bulk of the meeting answering questions from homeowners and told residents Oak Park has three areas prone to flooding but that the northeast corner of town — east of Ridgeland and between North Avenue and Division – is the hardest hit.
The meeting was convened because the area suffered significant flooding during June. While the officials said the area won’t see flood mitigation projects until 2017 at the earliest, most residents seemed pleased with the way the meeting panned out.
McKenna said there are several factors that make flood mitigation a challenge in Oak Park. There is no river – or other body of water – in the village, so all of the rainwater has to go through the sewers. The water gets moved to the Metropolitan Water Reclamation District’s plant further south, along with water from many other nearby municipalities, which means that, during heavy rains, the system can easily become overtaxed. While increasing the size of the pipes can improve capacity, there is only so far it can be increased before doing it becomes cost-prohibitive.
The problem is further compounded by the fact that most of Oak Park sits on clay soil, so the water doesn’t get readily absorbed.
And then, they said, northeast Oak Park has its own issues.
“You’re at the disadvantage of being at lower elevation than the surrounding area,” McKenna said. “What happens in the rainfall is that sewers starting to fill up. Eventually, the water will back up and it wants to be at lower elevation. So you’re fighting gravity at this point.”
After serious flooding in 2011, Oak Park commissioned a study on local flooding. Northeast Oak Park was identified as one of the three especially flood-prone zones. The others are in northwest and south Oak Park.
McKenna said, while addressing flooding in northeast Oak Park is the highest priority among flood mitigation projects, the area won’t see any large-scale projects until 2017. Wielebnicki said the village is still working out the details.
“[Oak Park is] developing the so-called hazard mitigation plan,” he said. “Because the way FEMA works – if you develop a hazard agitation plan that identifies certain improvements you can make to mitigate those hazards, there could be funding available. We actually tried this year, but it’s very competitive.”
In the meantime, the current sewer improvement project along the section of Ridgeland Avenue between Chicago Avenue and Division Street should help the area indirectly, because it will increase sewer capacity.
Wielebnicki also said Oak Park will relieve the strain on the sewers by trying to install as much green infrastructure as possible in the areas where soil isn’t clay. According to the map shared during the presentation, that area largely falls within the western half of Oak Park.
“What we’re talking about with green infrastructure is [things like] green alleys, with bricks with sand in between atop of sandy soil,” he said.
Projects like this allow water to seep into the ground, Wielebnicki said, reducing the amount of water that goes into the sewers.
The village is also planning to implement smaller-scale flood mitigation projects.
“One of the recommendations from [the flooding studies] is to install restrictors,” said McKenna. “The intent is to keep water on public property. We’re putting them throughout town, but the biggest focus is going to be here. We’ll try to do them system-wide on local streets.”
He said that Oak Park can’t put restrictors on major streets, because they need to be clear for emergency vehicles. In response to a question from a resident, McKenna also emphasized that the village learned from mistakes in 2011 and that it will be more careful about where it puts restrictors this time around.
“[Oak Park] went about it the wrong way years ago,” he said. “They flooded all sorts of cars and basements.”
In response to questions from the audience, McKenna and Wielebnicki went over what residents can do themselves to reduce flooding.
“There are two ways you can do it,” Wielebnicki said. “[The first wave is] what they call a backflow prevention valve. The other way is what they call overhead sewers.”
Oak Park has a grant program that would cover 50 percent of the costs of installing either of those systems. According to Oak Park’s website, the grants per home are capped at $3,500.
Wielebnicki also recommended disconnecting roof downspouts from the sewers, as well as using rain barrels. MWRD currently has a program where residents can get rain barrels for free by sending a request to public works.