Sewer System

Recent engineering studies analyzed four locations in our sewer system to determine if it could handle a heavy rain storm event. The current best engineering practice when installing new storm sewer systems is to design a system capable of handling a 10-year rain event, defined as either 2.1″ in a one hour period or 3.8″ in a twenty-four hour period. They found that our sewer system east of Green Bay Road was undersized and unable to handle large rainstorm events. These four locations are:

  • Oxford Road 676% under capacity
  • Melrose Avenue 482% under capacity
  • Kenilworth Avenue 319% under capacity
  • Abington Avenue164% under capacity

East of Green Bay Road has what is called a “combined sewer system,” meaning all of the sewage or septic water from houses, as well as storm water runoff, flow into the same system, which was not designed to handle large rain storms or the increased water runoff associated with today’s larger homes. If the water system reaches capacity during heavy rain, this water backs up through the lateral pipes connecting each house to the Village system, ultimately backing up through toilets, drains and other points in the home. The sewer system west of Green Bay Road has a newer separate system that keeps sanitary water and storm water in distinct places, which was implemented in the 1970’s through a referendum-approved bond issuance.


(This picture is from 2010 and shows Ivy Court looking south towards Joseph Sears School.)


(This picture is from 2010 and shows the corner of Cumberland and Abbotsford.)

10_year_map
Early sewer systems were sufficient for the Village for several reasons:

  • Less rainfall: Rainstorms were generally less intense than the record-breaking storms the Chicago area has seen in recent years.
  • Less wastewater: Without dishwashers, washing machines, garbage disposals, etc., each home produced less wastewater than today.
  • More open space: Water was allowed to pool and gradually soak into the ground in open areas that are now developed.
  • More pervious ground: More unpaved land allowed water to soak into the ground, rather than being directed into the sewers.

flooding_areas_map
(Areas of reported flooding from the HLR 2010 engineering study.)

The 2010 HLR sewer and watershed study is available HERE.