Allegheny River at Olean, NY
River level and flood forecast · Cattaraugus County
The river is 10.9 ft below flood stage (12 ft).
Forecast to hold near 1.1 ft through Sat, Oct 17, 8 AM.
Flow: 222 cubic feet per second (USGS).
The last 7 days and the forecast
NWS forecast issued Mon, Oct 12, 9:18 AM. Forecasts change as rain falls and as upstream water arrives.
Flood stages
| Major flood stage | 23 ft |
| Moderate flood stage | 17 ft |
| Flood stage | 12 ft |
| Action stage | 10 ft |
| Record crest (June 23, 1972) | 26.2 ft |
What floods at each level
From the National Weather Service, highest first.
- 25 ftExtreme flood, extensive residential flooding begins, especially upstream from Union Street bridge. Some evacuations necessary. Serious flooding upstream through Portville. Dikes overwhelmed.
- 23 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 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 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 ftAction stage, high flows. No flooding.
Highest crests on record
- 26.2 ft — June 23, 1972
- 23.3 ft — July 19, 1942
- 19.5 ft — March 8, 1956
- 19.3 ft — May 29, 1946
- 18.6 ft — January 20, 1996
Recent crests: 12.17 ft (April 14, 2024) · 13.33 ft (February 19, 2022) · 13.91 ft (January 14, 2018) · 14.17 ft (January 13, 2017) · 17.74 ft (December 3, 2010)
Up and down the river, and nearby
Not an official source. River levels, forecasts, flood stages and impacts are from the National Weather Service (OLNN6); flow from the U.S. Geological Survey. Readings are provisional. In a flood, follow your local officials and the NWS at weather.gov.