Flood Plain Information

In Winnetka, there are two sources of flood plain: the Skokie River (Base Flood Elevation 625.3 NAVD 1988) and Lake Michigan (Base Flood Elevation 585 NAVD 1988). Most of the flooding that occurs in Winnetka is not related to river flooding or elevated lake levels, but from flash flooding due to severe storm events.

During heavy rain, the capacity of the storm sewers is exceeded, and once stormwater starts pooling on the street surface, the potential for that water to infiltrate into the sanitary sewer system increases. As a result, basement back-ups can occur for those homes with a gravity sanitary sewer. Water can also enter into homes through basement window wells, exterior stairwells, and garages.

Winnetka’s Flood Plain & Stormwater Management

As part of the Village’s efforts to minimize and mitigate the effects of flooding, the Village participates and promotes the following:

  • The National Flood Insurance Program (NFIP), which makes federally guaranteed flood insurance available for all eligible buildings, whether they are in a floodplain or not.
  • The NFIP Community Rating System (CRS), which recognizes community efforts beyond Federal Emergency Management Agency’s (FEMA) minimum standards by reducing flood insurance premiums for the community’s property owners. The Village of Winnetka presently has a CRS Class 6 designation, allowing flood plain policy holders up to a 20% reduction in their flood insurance premiums, less additional non-policy fees associated with their premiums.

Flood-Prone and Repetitive Loss Areas – Draft Report Available 

The Village participates in the National Flood Insurance Program (NFIP) and Community Rating System (CRS). It is a voluntary program designed to reward a community for its flood mitigation efforts. This reward comes in the form of reduced premiums for flood insurance policyholders within the municipality's limit. The Village is currently analyzing areas that have repeatedly suffered damage from floods (known as Repetitive Loss Areas). Village consultant Baxter & Woodman is conducting the study and collecting the data in the area. They recently completed their analysis and shared the draft report with the Village, which is now available for residents and the public to review and provide any input or comments. A draft report on Repetitive Loss Area Analysis for Area #6 can be reviewed here (PDF)  or at the Village of Winnetka Public Works Facility (1390 Willow Road). 

Comments on the draft report can be sent to Obaid Khalid, Assistant Director of Engineering, and they will be accepted until September 30, 2025.