Rivers in New York
Allegheny River at Olean
Below flood stage
2.61ftStage
Observed Sun, Sep 20, 1:30 PM EDT
- Flood stage
- 12.00 ft
- Forecast crest
- 4.40 ftTue, Sep 22, 2:00 AM EDT
- Record crest
- 26.20 ft1972
Flood stages and impacts
| Category | Stage |
|---|---|
| Major flood | 23.00 ft |
| Moderate flood | 17.00 ft |
| Minor flood | 12.00 ft |
| Action | 10.00 ft |
- 25.00 ftExtreme flood, extensive residential flooding begins, especially upstream from Union Street bridge. Some evacuations necessary. Serious flooding upstream through Portville. Dikes overwhelmed.
- 23.00 ftMajor 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.
- 17.00 ftModerate 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.
- 12.00 ftFlood 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.
- 10.00 ftAction stage, high flows. No flooding.
Flood outlook
Chance of flooding, September to November
| Category | Chance |
|---|---|
| Minor flooding | 25% |
| Moderate flooding | Under 5% |
| Major flooding | Under 5% |
The three-month chances are the River Forecast Centers’ long-range flood outlook, issued September 15, 2026.
Crest history
22 crests on NOAA’s list since 1942.
| # | Date | Stage |
|---|---|---|
| 1 | June 23, 1972 | 26.20 ft |
| 2 | July 19, 1942 | 23.30 ft |
| 3 | March 8, 1956 | 19.50 ft |
| 4 | May 29, 1946 | 19.30 ft |
| 5 | January 20, 1996 | 18.60 ft |
| 6 | March 23, 1948 | 18.50 ft |
| 7 | November 27, 1950 | 18.10 ft |
| 8 | January 22, 1959 | 18.00 ft |
| 9 | June 22, 1989 | 17.84 ft |
| 10 | April 7, 1947 | 17.80 ft |
| 11 | December 3, 2010 | 17.74 ft |
| 12 | April 2, 1993 | 17.00 ft |
| 13 | February 19, 1976 | 16.40 ft |
| 14 | March 16, 2007 | 15.60 ft |
| 15 | January 10, 1998 | 15.50 ft |
| 16 | February 22, 1981 | 15.40 ft |
| 17 | January 13, 2017 | 14.17 ft |
| 18 | January 14, 2018 | 13.91 ft |
| 19 | March 22, 2003 | 13.60 ft |
| 20 | February 19, 2022 | 13.33 ft |
| 21 | March 11, 2009 | 12.34 ft |
| 22 | April 14, 2024 | 12.17 ft |
Most recent crests
- April 14, 2024: 12.17 ft
- February 19, 2022: 13.33 ft
- January 14, 2018: 13.91 ft
- January 13, 2017: 14.17 ft
- December 3, 2010: 17.74 ft
- March 11, 2009: 12.34 ft
- March 16, 2007: 15.60 ft
- March 22, 2003: 13.60 ft
- January 10, 1998: 15.50 ft
- January 20, 1996: 18.60 ft
Nearby
Upstream, downstream and the gauges around this one.
What this means
Forecasts by the Ohio River Forecast Center. Forecasts are issued routinely year-round. Stage may be affected by ice during winter months.
Sources
Stage, flood stages, impacts and crest history from NOAA’s National Water Prediction Service. Streamflow and the daily record from the U.S. Geological Survey.