With the first phase of the Flossmoor Road Viaduct Improvements Project complete, the village is seeking to move forward with its flood mitigation plans.
The Phase 1 stormwater design system incorporating permeable pavers and the water storage for the Berry Lane Drain Improvements project was put to the test on March 30 when the village received two inches of rain in less than an hour. Fortunately, they held up well.
Flooding throughout the village has been an ongoing issue for almost a century. Over the past two decades, the village has invested millions of dollars to address the issue. However, the frequency and intensity of rain events have risen in recent years, increasing the need for a solution.
“The number of flash flooding events has increased, so it’s our responsibility as the government to improve our infrastructure to address these issues,” said Flossmoor Village Manager Bridget Wachtel at the village board’s May 15 meeting. “This project is important to the entire Flossmoor community. It’s really going to be a legacy project for the village board, so it’s quite exciting to bring this discussion to you.”
Public Works Director John Burke, Assistant Public Works Director Dan Milovanovic, and Baxter & Woodman engineer Matt Moffitt presented a comprehensive plan to mitigate the flooding in the Heather Hill neighborhood.
As part of Phase 2 of the Flossmoor Road Viaduct Improvements project, the proposal calls for moving storm water from Sterling Avenue to a local detention basin behind Heather Hill Elementary School. The new drainage structure would redirect the flooding from the viaduct downstream away from downtown Flossmoor.
One plan calls for taking property from the Homewood-Flossmoor Park District and creating a retention site on land near the school that now has tennis courts.
The proposal would offer a 10-year protection plan for the viaduct. Burke said that Flossmoor would benefit from a 100-year protection plan, but that would be prohibitive in terms of land and cost. Instead, the proposed system would follow the “good neighbor” policy. He explained that rather than pushing the water elsewhere and making it another subdivision’s problem, the water will be held briefly before it’s discharged to the existing storm sewage system.
“The definition of protection plan is the chance of reoccurrence of a storm in any given year,” Moffitt said. “It’s based on a statistical analysis of all the rain in the last 100 years, and there is a one in 10 chance or 10% chance of rain occurring in a 10-year storm.”
While it’s difficult to predict the amount of rain the village receives in any storm, the proposed detention basin will help mitigate the water at the viaduct and throughout the Heather Hill neighborhood. In the event of a 10-year storm, the basin would not wholly eradicate flooding under the viaduct, but it would be passable for cars.
Since the basin would be so close to Heather Hill Elementary School, there were some concerns about a fence. A final decision has yet to be made on whether to include a fence along the detention basin or its height if implemented.
The village is still deciding about the aesthetics of the basin. Milovanovic shared ideas on how the public works project can be more than just a means to collect water but an opportunity to expand education in the village.
“For the most part, what you see is what you get,” Milovanovic said when describing another detention in the area. “It’s sort of a barren area, but it doesn’t have to be. It could be something that provides some aesthetic value to the community. What better place for educational signage than a school for kids to learn about wildlife, the environment and ecosystems.”
Trustee Rosalind Mustafa said the project could be tied into the school district’s curriculum to allow students to explore their surroundings.
“When you create that type of environment instead of forbidding students to go over there, you build respect and understanding of why it’s (the basin) protected, why it’s here, and why we take care of it,” Mustafa said. “So, we don’t want to go in there disturbing or destroying the site.”
The District 161 Board of Education will discuss the project at its meeting Monday, May 22. The board will meet at 6 p.m. in Normandy Villa, 41 E. Elmwood Drive in Chicago Heights.