Search
Menu

Explore

Hazards

Analysis

Rankings

Reference

Allegheny River at Olean

Highest listed crest 26.20 ftFlood stage 12.0 ft22 crests since 1942

The Allegheny River at Olean crested at major flood stage 2 times among the 22 crests the National Weather Service lists from 1942 to 2024. The highest, 26.20 ft on June 23, 1972, was major flooding, 14.20 feet above flood stage. 11 other gauges on the Allegheny River crested above flood stage within a week of it, 3 at their own highest listed crest.

The gauge

Highest listed crest
26.20 ft
June 23, 1972; 60,000 cubic feet per second
Flood stage
12.0 ft
Major flooding from 23.0 ft
Crests at major
2
68th of 160 gauges in New York
Most recent flood crest
April 14, 2024
12.17 ft, minor flooding
Location
Cattaraugus County
Near Olean (1.2 mi)

Flood stages

The thresholds the National Weather Service uses for this gauge today, and how many listed crests reached each.

Flood categories, Allegheny River at Olean
Action stage10.00—The level at which the NWS or its partners begin to take action
Flood stage (minor)12.010Apr 14, 2024Minimal or no property damage, but possibly some public threat
Moderate flood stage17.010Dec 3, 2010Some inundation of structures and roads near the stream
Major flood stage23.02Jun 23, 1972Extensive inundation of structures and roads

Every listed crest

22 crests from 1942 to 2024. Filled: at or above flood stage. Hover a crest for its date and stage.

Listed crests at the Allegheny River at Olean, 1942 to 2024 1015202530ft Flood stage 12.0 ftMajor 23.0 ft Jul 19, 1942: 23.30 ft, major flooding; 44,000 cubic feet per secondMay 29, 1946: 19.30 ft, moderate flooding; 29,500 cubic feet per secondApr 7, 1947: 17.80 ft, moderate flooding; 25,000 cubic feet per secondMar 23, 1948: 18.50 ft, moderate flooding; 27,200 cubic feet per secondNov 27, 1950: 18.10 ft, moderate flooding; 26,000 cubic feet per secondMar 8, 1956: 19.50 ft, moderate flooding; 30,700 cubic feet per secondJan 22, 1959: 18.00 ft, moderate flooding; 25,500 cubic feet per secondJun 23, 1972: 26.20 ft, major flooding; 60,000 cubic feet per secondFeb 19, 1976: 16.40 ft, minor flooding; 21,000 cubic feet per secondFeb 22, 1981: 15.40 ft, minor flooding; 18,000 cubic feet per secondJun 22, 1989: 17.84 ft, moderate flooding; 25,000 cubic feet per secondApr 2, 1993: 17.00 ft, moderate flooding; 22,500 cubic feet per secondJan 20, 1996: 18.60 ft, moderate flooding; 27,400 cubic feet per secondJan 10, 1998: 15.50 ft, minor flooding; 20,600 cubic feet per secondMar 22, 2003: 13.60 ft, minor flooding; 17,000 cubic feet per secondMar 16, 2007: 15.60 ft, minor flooding; 21,000 cubic feet per secondMar 11, 2009: 12.34 ft, minor flooding; 15,000 cubic feet per secondDec 3, 2010: 17.74 ft, moderate flooding; 27,300 cubic feet per secondJan 13, 2017: 14.17 ft, minor floodingJan 14, 2018: 13.91 ft, minor floodingFeb 19, 2022: 13.33 ft, minor flooding; 16,000 cubic feet per secondApr 14, 2024: 12.17 ft, minor flooding Highest, 26.20 ft, Jun 23, 1972 1960198020002020

Crests at or above flood stage, by decade

Crests at or above flood stage per decade, Allegheny River at Olean 1940s: 4 4 1950s: 3 1960s: 0 1970s: 2 1980s: 2 1990s: 3 2000s: 3 2010s: 3 2020s: 2 1940s1950s1960s1970s1980s1990s2000s2010s2020s
  1. These are the crests the local National Weather Service office lists for the gauge: the highest on record and recent crests. Lesser floods between them may be missing, so counts by decade are a floor.
  2. Categories use today's flood stages. Levees, dams and channel changes since a crest can make old and new stages not directly comparable.

Highest crests

Highest listed crests, Allegheny River at Olean
1Jun 23, 197226.20+14.20Major60,000
2Jul 19, 194223.30+11.30Major44,000
3Mar 8, 195619.50+7.50Moderate30,700
4May 29, 194619.30+7.30Moderate29,500
5Jan 20, 199618.60+6.60Moderate27,400
6Mar 23, 194818.50+6.50Moderate27,200
7Nov 27, 195018.10+6.10Moderate26,000
8Jan 22, 195918.00+6.00Moderate25,500
9Jun 22, 198917.84+5.84Moderate25,000
10Apr 7, 194717.80+5.80Moderate25,000
11Dec 3, 201017.74+5.74Moderate27,300
12Apr 2, 199317.00+5.00Moderate22,500
13Feb 19, 197616.40+4.40Minor21,000
14Mar 16, 200715.60+3.60Minor21,000
15Jan 10, 199815.50+3.50Minor20,600
16Feb 22, 198115.40+3.40Minor18,000
17Jan 13, 201714.17+2.17Minor—
18Jan 14, 201813.91+1.91Minor—
19Mar 22, 200313.60+1.60Minor17,000
20Feb 19, 202213.33+1.33Minor16,000
21Mar 11, 200912.34+0.34Minor15,000
22Apr 14, 202412.17+0.17Minor—

The worst floods along the Allegheny River

For this gauge's highest crests, the other gauges on the Allegheny River that crested above flood stage within a week.

June 23, 1972: 26.20 ft here, major flooding

July 19, 1942: 23.30 ft here, major flooding

  • EldredPA · Jul 19, 1942 · 27.30 ft · Major
  • SalamancaNY · Jul 20, 1942 · 14.55 ft · Moderate

March 8, 1956: 19.50 ft here, moderate flooding

Gauges on the Allegheny River

In USGS station-number order, which runs downstream within a river basin.

Flood gauges on the Allegheny River
EldredPA23.029.10 ft, Jun 23, 19722
Olean this gaugeNY12.026.20 ft, Jun 23, 19722
SalamancaNY12.024.01 ft, Jun 23, 19721
WarrenPA14.019.40 ft, Mar 17, 18656
West HickoryPA14.017.83 ft, Jan 25, 19643
FranklinPA17.026.00 ft, Feb 27, 19173
ParkerPA20.029.60 ft, Jan 22, 19592
Rimer Lock and DamPA19.021.80 ft, Jan 22, 19590
Mosgrove Lock and DamPA19.027.70 ft, Mar 10, 19642
Kittanning Lock and DamPA21.030.70 ft, Mar 26, 19136
Clinton Lock and DamPA21.026.40 ft, Mar 18, 19361
Freeport Lock and DamPA23.033.30 ft, Mar 18, 19361
Natrona Lock and DamPA21.032.10 ft, Mar 18, 19365
C.W. Bill Young Lock and DamPA17.031.10 ft, Mar 18, 19362
Sharpsburg Lock and DamPA21.026.90 ft, Jun 24, 19721

Other gauges in Cattaraugus County

Flood gauges in Cattaraugus County
Salamanca12.024.01 ft, Jun 23, 19721
Gowanda10.014.14 ft, Mar 7, 19561

Cattaraugus County: every hazard · River floods across the country · New York

NOAA National Water Prediction Service, gauge OLNN6, retrieved October 30, 2026. Stages in feet on the gauge's own datum, not elevation. Crests are as the National Weather Service lists them; preliminary values may be revised.