21' - This is the flood of record, which occurred on September 12 1971.
18.6' - Major flooding occurs. The water is to the Farm to Market 774 bridge floor.
17' - Major lowland flooding occurs. The river is 200 yards wide at the Farm to Market 774 bridge.
16' - Moderate lowland flooding occurs. The river rises to low steel of the Farm to Market 774 bridge.
12' - Minor lowland flooding occurs.
8' - Overbank conditions occur causing only nuisance flooding.
5' - The river reaches bankfull stage.