Rivers in Illinois
Illinois River at Ottawa
Below flood stage
459.60ftStage
Observed Wed, Sep 23, 2:30 PM CDT
- Flood stage
- 463.00 ft
- Record crest
- 473.72 ft2013
Flood stages and impacts
| Category | Stage |
|---|---|
| Major flood | 471.00 ft |
| Moderate flood | 467.00 ft |
| Minor flood | 463.00 ft |
| Action | 461.00 ft |
- 476.00 ftWater reaches the top of the levee at Ottawa High School.
- 475.50 ftBackwater causes the Fox River to reach the top of the flood protection wall south of Main Street near Ottawa High School. Water inundates lower-level of residences at Heritage Harbor east of Ottawa.
- 474.50 ftBackwater causes the Fox River to reach the top of the levee at Ottawa High School.
- 474.00 ftStructures threatened at Shoreline Boat Club in Ottawa. Main Street at Fox River in Ottawa is threatened and may be closed, blocking the last primary evacuation route for east Ottawa. Water overtops the berm at Waste Water Treatment Plant.
- 472.00 ftWest parking lot of St. Elizabeth Medical Center in Ottawa is inundated.
- 471.50 ftWater reaches top of levee at Ottawa Waste Water Treatment Plant. Backwater causes the Fox River to inundate the YMCA parking lot in Ottawa.
- 470.00 ftShabbona Street near Ottawa High School is inundated. St. Elizabeth Medical Center property in Ottawa is threatened including the loading dock areas.
- 469.00 ftBackwater causes the Fox River to reach bankfull near the YMCA in Ottawa.
- 468.00 ftRiver Rescue structure threatened in Ottawa.
- 467.00 ftGreen Street near Shoreline Boat Club in Ottawa is inundated, blocking a primary evacuation route for east Ottawa.
- 466.50 ftLow-lying sections of Fox River Park in Ottawa are inundated including Hudson Street River Walk. St. Clair Street is threatened in Ottawa.
- 465.50 ftLow-lying property near St. Elizabeth Medical Center is threatened. Marquette High School football field threatened.
- 465.00 ftHarbor Walk in Heritage Harbor east of Ottawa is inundated.
- 464.00 ftBackwater causes the Fox River to reach bankfull near St. Elizabeth Medical Center in Ottawa.
- 462.50 ftRoadway entrance to Allen Park threatened in Ottawa. Allen Park west boat ramp inundated in Ottawa.
- 461.00 ftRiver Rescue boat dock inundated in Ottawa.
Flood outlook
Chance of flooding, September to November
| Category | Chance |
|---|---|
| Minor flooding | 20% |
| Moderate flooding | 13% |
| Major flooding | 7% |
The three-month chances are the River Forecast Centers’ long-range flood outlook, issued August 28, 2026.
Crest history
24 crests on NOAA’s list since 2001.
| # | Date | Stage |
|---|---|---|
| 1 | April 19, 2013 | 473.72 ft |
| 2 | May 19, 2020 | 472.59 ft |
| 3 | September 16, 2008 | 472.21 ft |
| 4 | February 22, 2018 | 471.49 ft |
| 5 | May 2, 2019 | 470.83 ft |
| 6 | March 11, 2009 | 470.23 ft |
| 7 | December 29, 2008 | 468.87 ft |
| 8 | December 30, 2015 | 468.06 ft |
| 9 | May 13, 2002 | 468.00 ft |
| 10 | June 17, 2015 | 467.86 ft |
| 11 | December 12, 2005 | 467.80 ft |
| 12 | January 9, 2008 | 467.60 ft |
| 13 | May 2, 2017 | 466.46 ft |
| 14 | February 17, 2008 | 465.00 ft |
| 15 | March 31, 2017 | 464.33 ft |
| 16 | June 24, 2010 | 464.29 ft |
| 17 | July 23, 2017 | 464.10 ft |
| 18 | March 1, 2007 | 463.80 ft |
| 19 | October 16, 2017 | 463.65 ft |
| 20 | February 10, 2008 | 463.50 ft |
| 21 | March 3, 2008 | 463.10 ft |
| 22 | December 23, 2006 | 463.10 ft |
| 23 | June 7, 2001 | 462.00 ft |
| 24 | October 26, 2001 | 461.70 ft |
Most recent crests
- May 19, 2020: 472.59 ft
- May 2, 2019: 470.83 ft
- February 22, 2018: 471.49 ft
- October 16, 2017: 463.65 ft
- July 23, 2017: 464.10 ft
- May 2, 2017: 466.46 ft
- March 31, 2017: 464.33 ft
- December 30, 2015: 468.06 ft
- June 17, 2015: 467.86 ft
- April 19, 2013: 473.72 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.