| Flood Impacts |
| 25.2 | Estimated flood of record. All of Duncan floods except for Babbitt Heights and other high areas outside of the floodplain. |
| 24.0 | Large sections of Duncan flood including majority of business district and large number of residences. Highway 70 under several feet of water in several locations. |
| 22.0 | Portions of the business district and residences closest to the river begin to flood. Water running over top of highway bridge approach ramps in Duncan. Ball fields near High School under several feet of water. |
| 20.0 | Highway 70 bridge approach bottoms reached in Duncan. |
| 18.0 | Low-lying agricultural areas begin to flood. |
| 15.0 | Water approaches top of dike structures in isolated area near Duncan. |
