Rivers in Illinois
Mississippi River at Alton
Below flood stage
14.84ftStage
Observed Wed, Sep 30, 12:00 AM CDT
- Flood stage
- 21.00 ft
- Record crest
- 39.55 ft1993
Flood stages and impacts
| Category | Stage |
|---|---|
| Major flood | 31.00 ft |
| Moderate flood | 24.00 ft |
| Minor flood | 21.00 ft |
| Action | 20.00 ft |
- 39.00 ftNear this height, floodwaters will reach the floor of the Lincoln Shields gazebo in West Alton, Missouri.
- 38.70 ftNear this height U.S. Highway 67 will be completely closed.
- 36.70 ftThe railroad between Wood River and Alton begins flooding near this height.
- 32.00 ftAt this height, the waterpark playground will become inundated.
- 31.20 ftNear this height, the southbound lanes of U.S. Highway 67 will begin flooding, forcing the detour of southbound traffic onto the northbound lanes.
- 30.90 ftNear this height, water will begin flowing over Riverlands Way between Highway 67 and Mel Price Locks and Dam. This road is a part of the Consolidated North County levee, so this is the point when water begins gradually flowing onto the protected farmland and farm homes behind the levee.
- 30.80 ftThe intersection of West Broadway (Illinois 100) and U.S. Highway 67 will begin flooding near this height.
- 29.70 ftFloodwater begins damaging property in Elsah, Illinois and in Portage des Sioux, Missouri near this height.
- 29.20 ftNear this height, floodwater should begin to impact the base of the Ardent Mills grain bins.
- 28.20 ftAt this height, water will cover the sidewalk near the waterpark playground.
- 28.00 ftNear this height, the flood wall around the Argosy Casino will overtop, flooding the casino parking lot.
- 27.20 ftAt this height, Bloch Marine Service at Harbor Point Yacht Club begins flooding.
- 26.60 ftRoute 100 at Alton closes near this height.
- 25.50 ftHighway 100 will begin flooding at Clifton Terrace Street within 2 feet of this height.
- 24.60 ftMissouri Highway 94 from Alta Villa Road to Feltes Drive will be closed near this height.
- 24.50 ftHighway 100 begins flooding at the Clifton Terrace Street intersection near this height.
- 24.20 ftThe Wood River South Levee flood gate is closed near this height.
- 23.30 ftNear this height, the outer road between Riverlands Way and the Lincoln Shields Access Road will close due to flooding.
- 23.20 ftYachtview Drive begins flooding along the entrance to Harbor Point Yacht Club near this height.
- 22.20 ftMissouri Highway 94 between Portage Des Sioux and West Alton begins flooding. Yachtview Drive begins flooding along the entrance to Harbor Point Yacht Club.
- 21.70 ftAt this level, Highway 94 and the east end of Harbor Point Road off of Missouri Highway 94 north of West Alton begin flooding. Also, the access road the Lincoln Shields recreation area off of U.S. Highway 367 just west of the Clark bridge begins flooding.
- 20.70 ftDuring open river conditions (Mel Price gates all open), Alta Villa Road off of Highway 94 begins flooding and is closed.
- 19.70 ftDuring open river conditions (Mel Price gates are open), Dresser Island Drive begins flooding near this level.
Flood outlook
Chance of flooding, October to December
| Category | Chance |
|---|---|
| Minor flooding | Under 5% |
| Moderate flooding | Under 5% |
| Major flooding | Under 5% |
The three-month chances are the River Forecast Centers’ long-range flood outlook, issued September 25, 2026.
Crest history
39 crests on NOAA’s list since 1993.
| # | Date | Stage |
|---|---|---|
| 1 | August 1, 1993 | 39.55 ft |
| 2 | June 9, 2019 | 35.30 ft |
| 3 | January 1, 2016 | 31.94 ft |
| 4 | May 7, 2019 | 31.60 ft |
| 5 | May 22, 1995 | 31.43 ft |
| 6 | June 4, 2013 | 31.27 ft |
| 7 | May 6, 2017 | 31.02 ft |
| 8 | June 29, 2008 | 29.78 ft |
| 9 | June 30, 2015 | 29.11 ft |
| 10 | April 3, 2019 | 28.77 ft |
| 11 | April 17, 2002 | 28.27 ft |
| 12 | April 25, 2013 | 28.04 ft |
| 13 | June 2, 1996 | 26.46 ft |
| 14 | June 28, 2010 | 26.01 ft |
| 15 | September 19, 2008 | 25.95 ft |
| 16 | April 30, 2011 | 25.06 ft |
| 17 | June 9, 2001 | 24.99 ft |
| 18 | April 14, 1994 | 24.78 ft |
| 19 | April 17, 1998 | 24.74 ft |
| 20 | May 19, 2010 | 24.49 ft |
| 21 | June 20, 2011 | 24.45 ft |
| 22 | May 21, 2009 | 23.87 ft |
| 23 | October 17, 2018 | 23.71 ft |
| 24 | May 2, 1999 | 23.36 ft |
| 25 | March 30, 2010 | 23.36 ft |
Most recent crests
- May 1, 2026: 21.54 ft
- March 20, 2021: 21.70 ft
- June 1, 2020: 21.69 ft
- March 29, 2020: 20.30 ft
- October 13, 2019: 21.86 ft
- June 9, 2019: 35.30 ft
- May 7, 2019: 31.60 ft
- April 3, 2019: 28.77 ft
- October 17, 2018: 23.71 ft
- May 6, 2017: 31.02 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 precipitation and the precipitation amounts expected approximately 48 hours into the future from the forecast issuance time. River forecasts for this location take into account past precipitation and the precipitation amounts expected approximately 24 hours into the future from the forecast issuance time.
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.