A system of levees were constructed along the East Branch of the DuPage River, between Middleton Avenue and Maple Avenue, and along St. Joseph Creek between the river and Route 53. The levees were built in the 1960s by the Illinois Department of Transportation.
The levees provide protection from frequent flood events along the river. However, they can be overtopped in larger flood events and they can cause flooding behind the levee due to locally heavy rains being held behind the levee when the river is high. This condition occurred in September 2008 and in October 2017.
The local storm sewer system flows by gravity into the river. As the water in the river rises, the water presses down on the flap gates at the end of each storm sewer that extends through the levee. When the flap gates are closed, the flood water in the river can't flow back up the storm sewer but this also means the local storm water in the storm sewers can't get to the river. Four pump stations, operated by DuPage County, and the local storm sewer improvements that are connected to the pump stations were installed to pump the storm water in the residential neighborhoods north of the railroad over the levees.
Localized flooding will still occur in low areas not drained by the storm sewers or when the storm sewer flow is greater than the pump station capacity. Leveed areas without pump stations, such as Community Park, will flood during locally heavy rain and river flooding.
In 2012, the Village completed the East Branch DuPage River Levee Study (see Quick Links). The study outlined over $9 million worth of improvements and repairs, including the removal of utility poles, stabilization of stream banks, removal of trees and encroaching structures, capping portions of the levee with clay, stabilizing the foundation with pressure injected grout and acquiring necessary easements for maintenance and improvements.
In 2015, DuPage County teamed with the US Army Corps of Engineers and Will County to look at the levees as part of an overall look at flooding throughout the DuPage River basin. They are developing a DuPage River Feasibility Study, developing a range of possible structural and non-structural alternatives to address flooding. A draft of this report is scheduled for early 2018.