Winnetka Considers Building an $8 Million Storm Water Tunnel

Nearly a year after a July 23 storm caused throughout Winnetka, Village Engineer Steve Saunders made a presentation to the Tuesday, updating them on the progress made and the many improvements still to come. 

As many as 1,100 of the village’s 4,000 homes were damaged in some way by the flooding last July, when some 6.6 inches of rain swamped the area in less than 24 hours, Sanders said. 

“This is as intense a flood as I have seen in my 25 years with the village,” Saunders said. 

The village had already been working on improving its storm water management systems after significant floods in 2007 and 2008, but Saunders says those would have done little to improve situation in 2011.

Now staff is looking into updating the system to plan for 100-year storms that could drop up to 7.5 inches in 24 hours. 

Storm water master plan in the works

The primary improvement would be the creation of an $8-million Willow Road storm water tunnel, an eight-foot diameter pipe that would funnel water into Lake Michigan.

Staff has already determined the solution is feasible and has met with Rep. Robert Dold (R-Kenilworth) and state reps Daniel Biss (D-Evanston) and Robyn Gable (D-Evanston) to get the officials’ help clearing the project with regulatory agencies and looking for additional sources of funding. 

Engineering firm Christopher Burke and Associates identified less expensive projects that the village could undertake to improve flood readiness for north Winnetka, which would not be connected to the tunnel. These are tentatively scheduled to be open to Council and resident comment Aug. 25. 

The village has also paid more than $100,000 to engineering firm Baxter and Woodman to develop a , which would provide a roadmap for the village’s storm water projects for the next five to 10 years. 

Saunders also provided an update on Winnetka’s sanitary sewer system, which backed up into some Winnetka homes during the flood last July.

Strand Associates has analyzed the system and identified flooding clusters where they will look for improper connections between the system that handles residential waste and the storm water sewer. In addition to preventing backups, making these changes reduces the chance of beach closures due to bacteria contamination. The village has already repaired two cross-connections and is working with residents to clean up 15 more. 

Keeping residents informed

The village has worked to directly involve residents in the process, encouraging owners of older homes to install devices that prevent sewage from backing up into basements. The homeowners can be reimbursed for the improvements if they allow village staff to inspect their homes for other issues. 

Staff continues to work to keep residents appraised of storm water developments through a dedicated section of the village’s website. They will also be presenting a seminar offering residents tips on how to prevent flooding and an update on the village’s plans Sept. 19. 

About 700 properties in Winnetka are in FEMA-designated flood plains, meaning they are required to have flood insurance to get a mortgage. Winnetka has applied for FEMA’s community rating system, which evaluates how the village regulates flooding. If Winnetka receives a good rating, it could save residents between 5 percent and 45 percent on their insurance. 

“I think we've gone from not having to a plan to have a very robust plan,” Saunders said. “We've accomplished a lot in a year. We're on a roll, but we've still got a ways to go and we've got some hard decisions to make.” 

Resident: Increase Will Road tunnel size

Resident John Hirschey said that his home in the 400 block of Sunset Road experienced sewer backup and asked that the village cover the cost of a street level sewer connections for any areas they weren’t planning on improving. He also urged the council to increase the size of the Willow Road tunnel so it would be capable of dealing with 250-year storms. 

Saunders responded that Hirschey’s home was in an area that he recommended the village work on, but that he didn’t think a bigger tunnel was necessary. 

“I can tell you that 100 years is what FEMA has settled on for deciding what's a floodplain, and that's typically what's looked at,” he said. “Anything with a greater return would extend into areas that are statistically unlikely to flood.”

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