After experiencing two severe flood events, the Village of Winnetka hired CBBEL to perform a flood risk reduction analysis. Both storm events caused widespread flooding consisting of streets, backyards, and homes throughout Winnetka. Following the conclusion of these studies, the Village experienced the July 2011, 100-year storm event which prompted the Village to seek stormwater solutions to provide a level of protection for larger storm events. The previous studies were then expanded to determine the cost to provide 25-, 50- and 100-year level of protection.

The study was divided into 8 areas using information obtained from the Village, field visits conducted during storm events, more than 850 flood damage questionnaires and information obtained through a series of public meetings. CBBEL recommended implementing specific drainage improvements in each of the study areas including relief storm sewers and storage areas. CBBEL also recommended a new outlet to Lake Michigan consisting of an eight foot diameter tunnel design to provide flood protection for multiple study areas.

The Details


Winnetka, Illinois

Construction Cost/Fee

NA / $176 thousand


Village of Winnetka