A northern suburb’s plan to combat frequent flooding may wind up impacting its beaches and the source of drinking water for millions of people, according to opponents of a proposed tunnel project in Winnetka.
“The tunnel will pollute. Make no mistake about that,” said tunnel opponent Matt Wendt.
The proposed tunnel would send excessive storm water runoff down a 7900 foot pipeline along Willow Road and into Lake Michigan. The plan is expected to include a treatment mechanism designed to keep contaminants out of the lake.
However, Wendt and other residents who argue against the project said chemicals from lawns and streets would still manage to slip into Lake Michigan. They also fear the village’s water quality problems would be made even worse by the tunnel. The Illinois Environmental Protection Agency determined four of the village’s beaches to be impaired last year due to high bacteria levels.
The Better Government Association is researching the issue and said it has ramifications all along the shore in communities that need to balance flood control and concerns about Lake Michigan.
“What Winnetka does to control their flooding is going to have an impact on not only its nearby neighbors but on all of us who use the lake,” said Brett Chase of the BGA.
While village leaders said the project would not go forward if strict water quality standards cannot be met, Winnetka is facing a major dilemma: what to do with emergency storm water runoff the next time a 100 year flood hits the area.
Major floods in 2008, 2011 and 2013 damaged buildings and flooded basements in parts of Winnetka.
“Eighteen inches of standing water represent sort of a life safety hazard for people,” tunnel supporter Christina Codo said. “You can’t get access to the streets.”
Storm water on the village’s east side already enters Lake Michigan through water outlets and natural streams. The village said it uses existing drainage infrastructure in the western part of Winnetka to keep as much runoff water flowing west as possible.
During severe storms, however, areas holding water runoff west of the village fill up fast.
The village has awarded a contract to the engineering firm MWH to provide design engineering and permitting services to move the project forward. The estimated cost of the tunnel project is $34.5 million.
“The village looked at a number of options to provide flood risk reduction, and the least costly and most feasible project to protect structures against flooding from large rain events is the proposed Willow Road Project,” wrote village manager Robert Bahan in an email to NBC 5 Investigates.
The project has the support of the Winnetka Homeowners Association (WHOA).
“This would more than help,” said WHOA co-manager Ann Dillon.
However, a slight majority of residents voted against the project in a March advisory referendum.
“This is a regional issue. The lake belongs to everybody and any pollution we put in the lake is going to Wilmette, to Evanston, to Chicago, to Calumet and on and on,” said opponent Debbie Ross.
Ross said the village and its residents should consider more environmentally-friendly options to prevent floods, such as permeable surfaces and additional green infrastructure.
Village leaders said the referendum vote would not end the project or relieve the Village Council of its statutory duty to protect the health, safety and welfare of thousands of residents.
“The Village has been working on the storm water program for several years, cannon further delay this important work and needs to continue to develop effective solutions to the flooding problem,” Bahan wrote.
The project is by no means a done deal.
Winnetka must go through a rigorous permitting process before tunnel construction could begin. The primary regulatory agencies that must approve the project include the Illinois EPA, Illinois Department of Natural Resources, Metropolitan Water Reclamation District of Greater Chicago and the US Army Corp of Engineers.
“We want to make sure that as storm water is being managed on a quantity side that they’re also managing it from a quality standpoint,” said Marcia Willhite of the Illinois EPA.