Observation history unavailable for thie location.
This level is expected to be met or exceeded on average once every 500 years.
This is the RECORD FLOOD LEVEL that was reached on August 1 1993.
This level is expected to be met or exceeded on average once every 200 years.
This river level is expected to be exceeded once in every
Nutwood Levee is Overtopped
This flood level was reached on April 28 1973.
Water Treatment plant is inundated
This river level is expected to be exceeded once in every 50 years.
Methodist Church at Main St. and Vine St. begins flooding.
Runways and Hangers at Smartt Airfield are flooded.
The hanger at the north end of Smartt field begins to flood
This level is expected to be met or exceeded on average once every 25 years.
This level is expected to be met or exceeded on average once every 20 years.
Water reaches Main at Church Street
Route 100 between Grafton and Alton inundated. This is also designated as the Major flood level.
The Northwest and Northeast corners of Smartt Field are flooded
Water reaches Main Street at the Vistors Center
Water reaches the intersection at Main & Route 100. Also at this level the Northeast Corner of Smartt Airfield begins flood.
Beasleys Fish Market at Main & Overmeyer floods.
Majors Motel at Main & Dagget Hollow floods
Residential flooding in Grafton occurs
Water distribution system begins to flood so emergency measures begin.
This level is expected to be met or exceeded on average once every 5 years.
Gables Resturant at Main & Sycamore floods
Brussels Ferry closes.
West End Fish Market at Main & Canal floods.
City of Grafton closes Route 100. Also at this level the Catholic Church at Main & Evans floods.
Route 100 inundated at Chautaqua and Elsah. This is also designated as the Moderate flood level.
Main Street... Route 100... is inundated
Flooding begins to overtop the Levee in West Alton.
In Portage des Sioux, MO, Le Sieur Street leading to the Marina and to Our Lady of the River Statue is flooded.
This level is expected to be met or exceeded on average once every 2 years.
Flood Stage. Right bank begins to over flow... flooding farmland.
For navigational purposes through Alton Lock and Dam control, the Corps will not allow the river to exceed this level, if at all possible.
For safe navigation of barge traffic, the Corps will try to keep the river above this level.
Low Water Records
1) 38.15 ft on 08/01/1993
2) 33.12 ft on 04/28/1973
3) 32.13 ft on 06/18/1844
4) 30.40 ft on 05/29/1995
5) 29.70 ft on 10/09/1986
6) 28.30 ft on 04/10/1983
7) 28.20 ft on 04/29/1993
8) 28.10 ft on 05/16/2002
9) 27.70 ft on 12/08/1982
10) 27.55 ft on 05/05/1985
Historical low water information is not available.