| 33.5 |
Nutwood Levee is Overtopped |
| 33.0 |
Water Treatment plant is inundated |
| 32.1 |
Methodist Church at Main St. and Vine St. begins flooding. |
| 31.0 |
The hangars at the south end of Smartt field begin to flood. |
| 30.1 |
Restaurant at Main St. and Maple St. floods. |
| 29.1 |
Water reaches Main at Church Street |
| 29.0 |
Route 100 between Grafton and Alton inundated. This is also designated as the Major flood level. |
| 28.8 |
Water begins entering the north hangars at Smartt Field. |
| 28.5 |
Water begins entering the ramps on the north end of Smartt Field as the northwest and northeast corners are already flooded. |
| 28.4 |
Water reaches Main Street at the Vistors Center |
| 28.3 |
Intersection at Main (Route 100) & Route 3 is closed. Also at this level the Northeast Corner of Smartt Airfield begins flood. |
| 27.6 |
Beasley's Fish Market at Main & Overmeyer floods. |
| 27.5 |
Motel at Main & Dagget Hollow floods |
| 26.4 |
Residential flooding in Grafton occurs |
| 26.0 |
Water distribution system begins to flood so emergency measures begin. |
| 25.6 |
Car Wash at Main & Sycamore floods |
| 25.5 |
Brussels Ferry closes. |
| 25.2 |
West End Fish Market at Main & Canal floods. |
| 25.0 |
Route 100 begins flooding near Chautaqua and Elsah. |
| 24.9 |
Water reaches the intersection of Main St. and Edwards St. |
| 24.7 |
City of Grafton closes Route 100. Also at this level the Catholic Church at Main & Evans floods. This represents the lowest point on Main Street in Grafton. |
| 24.0 |
Moderate flooding begins. |
| 23.8 |
Main Street... Route 100... is inundated |
| 23.0 |
Highway 94 north of West Alton begins to flood. |
| 21.5 |
In Portage des Sioux, MO, Le Sieur Street leading to the Marina and to Our Lady of the River Statue is flooded. |
| 21.0 |
Water begins flooding the floor at the Palisades Marina in Portage Des Sioux. |
| 18.0 |
Flood Stage. Right bank begins to over flow... flooding farmland. |
| 16.2 |
For navigational purposes through Alton Lock and Dam control, the Corps will not allow the river to exceed this level, if at all possible. Above this level, water inundates land not owned by the USACE. |
| 14.2 |
For safe navigation of barge traffic, the Corps will try to keep the river above this level. |
weather.gov 
