National Weather Service United States Department of Commerce

Effective April 15, 2021, flood warning services will begin for the North Branch Chicago River at Chicago (Grand Avenue). Flood impact categories will also change. These changes are the result of collaboration with multiple partner agencies and stakeholders.

Click here for the service change notice issued March 1, 2021, announcing these changes.


North Branch Chicago River at Chicago (Grand Avenue)


Action Stage
Change from 2.0 feet to 1.0 feet

Minor Flood Stage
Unchanged at 3.0 feet

Moderate Flood Stage

Change from 5.0 feet to 4.0 feet

Major Flood Stage
Change from 6.0 feet to 5.0 feet


River flood advisories for this location will now be issued when the water level has reached, or is expected to reach, action stage. River flood warnings will be issued when the water level has reached, or is expected to reach, minor flood stage. Due to the current limited forecast capabilities for this complicated waterway, forecast crests will have higher than average uncertainty and will be rounded to the nearest whole foot.

This expanded service is due to a collaboration between the National Weather Service, Chicago's Office of Emergency Management and Communications, the Metropolitan Water Reclamation District of Greater Chicago, and the US Army Corps of Engineers.


This gauge represents the river reach from the confluence with the North Shore Channel downstream to the Chicago Sanitary and Ship Canal near  IL-171 at Summit, including the Chicago River in downtown Chicago.