Thorn Creek at Thornton, IL
River level and flood forecast · Cook County
Normal2.8 ftas of Mon 3:30 PM
The river is 6.2 ft below flood stage (9 ft).
Flow: 46 cubic feet per second (USGS).
The last 7 days and the forecast
NWS forecast issued Mon, Sep 21, 6:14 PM. Forecasts change as rain falls and as upstream water arrives.
Flood stages
| Major flood stage | 15.5 ft |
| Moderate flood stage | 14 ft |
| Flood stage | 9 ft |
| Action stage | 7.5 ft |
| Record crest (June 14, 1981) | 17.06 ft |
What floods at each level
From the National Weather Service, highest first.
- 22 ftChicago & Eastern Illinois Railroad tracks may be threatened near Glenwood.
- 21 ftI-94 may be threatened near 170th Street in South Holland.
- 20 ftStructures may be threatened along Clyde Avenue, 173rd Street, and 173rd Place in South Holland.
- 19 ftI-294/I-80 may be threatened west of the creek near the Lincoln Oasis. Residential structures may be threatened along Everett Avenue, Cregier Avenue, and Vollbrecht Road in South Holland. Clyde Avenue, 173rd Street, and 173rd Place may be threatened in South Holland.
- 18.5 ftIndustrial structures may be threatened along Bernice Road in South Holland.
- 18 ftMargaret Street threatened in Thornton.
- 17.5 ftResidential structures may be threatened along Kimbark Avenue, University Avenue, and 173rd Street in South Holland.
- 17 ftKimbark Avenue, University Avenue, 173rd Street, Everett Avenue, Cregier Avenue, and Vollbrecht Road may be threatened in South Holland. Thorn Creek Diversion Tunnel reaches capacity.
- 16 ftResidential structures threatened along Margaret Street in Thornton.
- 15.5 ftStructures threatened at Glenwood Academy. Residences threatened along Park Drive in Glenwood. 170th Street may be threatened in South Holland.
- 15 ftIndustrial structures threatened south of Margaret Street in Thornton.
- 14.5 ftPark Drive threatened in Glenwood. Industrial parking lots threatened south of Margaret Street in Thornton.
- 13.5 ftChicago Heights Glenwood Road threatened in Glenwood. Residential parking lots threatened along Margaret Street in Thornton.
- 13 ftParking lots threatened at Glenwood Academy.
- 12 ftStructures threatened along Glenwood Thornton Road north of Glenwood.
- 11.5 ftGlenwood Thornton Road threatened north of Glenwood.
- 11 ft187th Street threatened in Glenwood.
- 9 ftWater begins to be diverted through Thorn Creek Diversion Tunnel.
- 8 ftAthletic fields are inundated at Glenwood Academy.
- 7 ftWater overflows low-lying banks in Glenwood, Thornton, and South Holland.
Highest crests on record
- 17.06 ft — June 14, 1981
- 16.87 ft — November 28, 1990
- 16.24 ft — July 18, 1996
- 16 ft — July 13, 1957
- 15.95 ft — December 3, 1982
Recent crests: 9.95 ft (May 9, 2021) · 12.07 ft (May 18, 2020) · 11.41 ft (April 30, 2020) · 11.13 ft (January 11, 2020) · 10.08 ft (October 27, 2019)
Up and down the river, and nearby
- UpstreamThorn Creek at Glenwood, IL
- DownstreamLittle Calumet River at South Holland, IL
- Butterfield Creek at Flossmoor, IL
- Deer Creek near Chicago Heights, IL
- Calumet Union Drainage Canal at Markham, IL
- Little Calumet River at Munster, IN
- Lansing Ditch near Lansing, IL
- Little Calumet River at Munster (Northcote Avenue), IN
Not an official source. River levels, forecasts, flood stages and impacts are from the National Weather Service (THNI2); flow from the U.S. Geological Survey. Readings are provisional. In a flood, follow your local officials and the NWS at weather.gov.