Rivers in Illinois

Mazon River near Coal City

Grundy County, IllinoisNWS COLI2USGS 05542000Romeoville office

Below flood stage
2.01ftStage

Observed Tue, Sep 22, 9:45 AM CDT

Flood stage
12.00 ft
Record crest
21.00 ft1924

Open the live map with the river flood outlook

Flood stages and impacts

CategoryStage
Major flood19.00 ft
Moderate flood16.00 ft
Minor flood12.00 ft
Action10.00 ft
  1. 24.00 ftResidential structures may be threatened along Forest Drive and West Avenue west of Coal City.
  2. 22.00 ftStructures may be threatened along Spring Road west of Coal City. Whitetie Road may be threatened west of Coal City.
  3. 20.00 ftIL-113, Pine Bluff Road, and McArdle Road may be threatened west of Coal City. Reed Road may be threatened southwest of Coal City.
  4. 18.00 ftSpring Road may be threatened west of Coal City.
  5. 16.00 ftGorman Road and Grand Ridge Road may be threatened southwest of Coal City. Widespread inundation of agricultural land occurs.
  6. 15.00 ftWater may begin to overflow into nearby lakes along the river.
  7. 12.00 ftLow-lying agricultural land is inundated west of Coal City.
  8. 10.00 ftLow-lying agricultural land is inundated northwest of Coal City near the Illinois River.
  9. 8.00 ftWater overtops low-lying banks along the river west of Coal City.

Flood outlook

Chance of flooding, September to November

CategoryChance
Minor flooding13%
Moderate floodingUnder 5%
Major floodingUnder 5%

The three-month chances are the River Forecast Centers’ long-range flood outlook, issued August 28, 2026.

Crest history

72 crests on NOAA’s list since 1924.

#DateStage
1August 8, 192421.00 ft
2July 15, 195819.70 ft
3December 4, 198219.51 ft
4November 28, 199018.83 ft
5September 15, 200818.54 ft
6April 25, 195018.50 ft
7May 15, 197018.15 ft
8June 26, 196818.11 ft
9April 18, 201318.00 ft
10May 18, 202017.88 ft
11February 24, 198517.80 ft
12February 7, 194217.28 ft
13February 13, 198416.82 ft
14November 19, 198516.75 ft
15May 1, 201916.41 ft
16December 29, 201516.40 ft
17April 23, 194416.22 ft
18April 12, 197916.19 ft
19May 12, 194316.13 ft
20March 9, 200915.80 ft
21May 8, 201215.48 ft
22June 2, 198015.37 ft
23April 5, 194715.31 ft
24January 14, 200515.22 ft
25September 2, 198915.17 ft

Most recent crests

  • June 28, 2021: 10.81 ft
  • May 18, 2020: 17.88 ft
  • April 30, 2020: 13.04 ft
  • May 1, 2019: 16.41 ft
  • February 21, 2018: 12.87 ft
  • May 1, 2017: 11.35 ft
  • August 29, 2016: 11.57 ft
  • July 19, 2016: 13.78 ft
  • December 29, 2015: 16.40 ft
  • June 27, 2015: 11.75 ft

Nearby

Upstream, downstream and the gauges around this one.

What this means

Forecasts by the North Central River Forecast Center. Forecasts are issued as needed during times of high water, but are not routinely available. River forecasts for this location take into account past and future precipitation. The stages/flows that will occur may be different if future rainfall is different than forecast.

Sources

Stage, flood stages, impacts and crest history from NOAA’s National Water Prediction Service. Streamflow and the daily record from the U.S. Geological Survey.