River stage
Olean, Allegheny River
- River level
- 1.24 ft
- Status
- Below flood stage
- 7-day change
- -0.03 ft
- Recent high
- 5.28 ft
- Recent low
- 1.02 ft
Last reported 2026-10-13 | NWS OLNN6
- 30-day change
- -4.04 ft
- Average
- 1.94 ft
- Readings
- 122
- Data span
- 122 days
- Record crest
- 26.20 ft
In brief
The Allegheny River at Olean, NY read 1.24 ft on Oct 13, 2026, 8.76 ft below action stage. That is 4.04 ft lower than 30 days earlier.
Source: National Weather Service gauge OLNN6
River level timeline
Stage threshold profile
Highest crests on record
| Rank | Crest | Date |
|---|---|---|
| 1 | 26.20 ft | 1972-06-23 |
| 2 | 23.30 ft | 1942-07-19 |
| 3 | 19.50 ft | 1956-03-08 |
| 4 | 19.30 ft | 1946-05-29 |
| 5 | 18.60 ft | 1996-01-20 |
| 6 | 18.50 ft | 1948-03-23 |
| 7 | 18.10 ft | 1950-11-27 |
| 8 | 18.00 ft | 1959-01-22 |
Flood crests recorded at this gauge by the National Weather Service.
What happens at each level
- 10.00 ft
Action stage, high flows. No flooding.
- 12.00 ft
Flood stage, flooding possible on Union Street in Allegany and East Riverside Drive 1 to 3 miles upstream of Olean. Some farm lands along the river are also impacted.
- 17.00 ft
Moderate flood, water affects Riverview School of Aviation, 1.5 miles upstream of Union Street bridge. Local flooding occurs in areas unprotected by dikes including portions of Portville upstream.
- 23.00 ft
Major flood, protective dikes begin to be topped. Some roadway flooding in residential areas of city begins, especially upstream. Serious flooding in areas unprotected by dikes including portions of Portville.
- 25.00 ft
Extreme flood, extensive residential flooding begins, especially upstream from Union Street bridge. Some evacuations necessary. Serious flooding upstream through Portville. Dikes overwhelmed.
Written by the local National Weather Service forecast office for this exact gauge.
Frequently asked questions
Is the Allegheny River flooding at Olean?
No. The Allegheny River at Olean is at 1.24 ft, 8.76 ft below action stage.
What is the flood stage at Olean?
The National Weather Service sets action stage 10 ft, minor flooding 12 ft, moderate flooding 17 ft and major flooding 23 ft.
What is the highest the Allegheny River has been at Olean?
The highest crest on record is 26.2 ft, on 1972-06-23.
Is the Allegheny River high or low right now at Olean?
At 1.24 ft it is higher than 13% of readings over the last 122 days.
Stage and flood information from the NOAA National Weather Service (gauge OLNN6); daily history from the U.S. Geological Survey (site 03010820). Last reading 2026-10-13. For flood safety decisions always follow official National Weather Service warnings.