Mississippi River at Grafton, IL
River level and flood forecast · Jersey County
Normal15.8 ftas of Mon 3 PM
The river is 4.2 ft below flood stage (20 ft).
Forecast to fall to 14.9 ft by Mon, Oct 26, 7 AM.
Flow: 104,000 cubic feet per second (USGS).
The last 7 days and the forecast
NWS forecast issued Mon, Oct 12, 10:08 AM. Forecasts change as rain falls and as upstream water arrives.
Flood stages
| Major flood stage | 29 ft |
| Moderate flood stage | 24 ft |
| Flood stage | 20 ft |
| Action stage | 18 ft |
| Record crest (August 1, 1993) | 38.17 ft |
What floods at each level
From the National Weather Service, highest first.
- 37 ftNear this height, floodwater begins to impact Grafton City Hall.
- 33.5 ftNutwood Levee is Overtopped.
- 32.1 ftMethodist Church at Main St. and Vine St. begins flooding.
- 31 ftThe hangars at the south end of Smartt field begin to flood.
- 30.9 ftMissouri Route B from Washeon Road to Seeburger Road is closed near this height.
- 30.1 ftWater reaches the intersection of Main Street and Maple Street.
- 29.1 ftWater reaches Main at Church Street.
- 29 ftRoute 100 between Grafton and Alton at Clifton Terrace is flooded near this height.
- 28.8 ftWater begins entering the north hangars at Smartt Field.
- 28.5 ftWater begins entering the ramps on the north end of Smartt Field as the northwest and northeast corners are already flooded.
- 28.4 ftWater reaches Main Street at the Vistors Center
- 28.3 ftIntersection at Main (Route 100) & Route 3 is closed. Also at this level the Northeast Corner of Smartt Airfield begins flooding. Grafton Hills Drive is closed to all but local and select (UPS, FedEx, and Amazon) delivery traffic.
- 28 ftAgricultural levee north of Highway 370 is overtopped, flooding a St. Peters recreational area around a lake near 370 and Truman.
- 27.6 ftBeasley Fish Market at Main Street and Overmeyer begins flooding.
- 27.5 ftThe intersection at Main Street and Dagget Hollow begins flooding.
- 26.5 ftAt this height the entrance to the Illinois Youth Center-Pere Marquette becomes flooded, forcing the evacuation of those staying there.
- 26.4 ftResidential flooding in Grafton occurs.
- 26 ftWater distribution system begins to flood so emergency measures begin.
- 25.6 ftWater surrounds base of Aerie's Resort at Main Street (Hwy 100) near Market.
- 25.5 ftBrussels Ferry closes near this height. O'Jan's Fish Stand in Grafton closes near this height.
- 25.2 ftThe intersection at Main Street and Canal Street begins flooding.
- 25 ftBall field south of Main Street and Hawg Pit BBQ begin flooding.
- 24.9 ftWater reaches the intersection of Main St. and Edwards St.
- 24.7 ftCity of Grafton begins to detour traffic along Route 100 (Main Street) at Evans Street. Also at this level the Catholic Church parking lot at Main & Evans begins flooding. This represents the lowest point on Main Street in Grafton.
- 24 ftRoads within Chautauqua and Elsah begin flooding near this height.
Highest crests on record
- 38.17 ft — August 1, 1993
- 35.17 ft — June 7, 2019
- 33.12 ft — April 28, 1973
- 32.1 ft — May 7, 2019
- 30.94 ft — June 4, 2013
Recent crests: 20.13 ft (May 16, 2024) · 20.71 ft (May 2, 2024) · 20.8 ft (May 10, 2023) · 21.28 ft (May 7, 2022) · 20.66 ft (April 14, 2021)
Up and down the river, and nearby
Not an official source. River levels, forecasts, flood stages and impacts are from the National Weather Service (GRFI2); flow from the U.S. Geological Survey. Readings are provisional. In a flood, follow your local officials and the NWS at weather.gov.