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Long Tom River at Monroe

Highest listed crest 10.42 ftFlood stage 9.0 ft13 crests since 1964

The Long Tom River at Monroe crested above flood stage 11 times among the 13 crests the National Weather Service lists from 1964 to 2019. The highest, 10.42 ft on January 15, 1974, was minor flooding, 1.42 feet above flood stage.

The gauge

Highest listed crest
10.42 ft
January 15, 1974; 10,500 cubic feet per second
Flood stage
9.0 ft
Major flooding from 12.0 ft
Crests at major
0
11 above flood stage
Most recent flood crest
April 9, 2019
9.11 ft, minor flooding
Location
Benton County
Oregon

Flood stages

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

Flood categories, Long Tom River at Monroe
Action stage8.52Jan 19, 2012The level at which the NWS or its partners begin to take action
Flood stage (minor)9.011Apr 9, 2019Minimal or no property damage, but possibly some public threat
Moderate flood stage11.00—Some inundation of structures and roads near the stream
Major flood stage12.00—Extensive inundation of structures and roads

Every listed crest

13 crests from 1964 to 2019. Filled: at or above flood stage. Hover a crest for its date and stage.

Listed crests at the Long Tom River at Monroe, 1964 to 2019 89101112ft Flood stage 9.0 ftMajor 12.0 ft Dec 26, 1964: 10.06 ft, minor flooding; 9,520 cubic feet per secondJan 26, 1970: 9.03 ft, minor flooding; 7,190 cubic feet per secondJan 21, 1972: 9.59 ft, minor flooding; 7,920 cubic feet per secondJan 15, 1974: 10.42 ft, minor flooding; 10,500 cubic feet per secondDec 6, 1981: 9.47 ft, minor flooding; 7,990 cubic feet per secondFeb 22, 1986: 9.17 ft, minor flooding; 7,260 cubic feet per secondJan 14, 1988: 8.87 ft, action stage; 6,530 cubic feet per secondFeb 7, 1996: 10.08 ft, minor flooding; 9,560 cubic feet per secondNov 19, 1996: 9.04 ft, minor flooding; 6,940 cubic feet per secondDec 28, 1998: 9.33 ft, minor flooding; 7,610 cubic feet per secondJan 18, 2006: 9.54 ft, minor flooding; 8,138 cubic feet per secondJan 19, 2012: 8.93 ft, action stage; 6,620 cubic feet per secondApr 9, 2019: 9.11 ft, minor flooding; 7,039 cubic feet per second Highest, 10.42 ft, Jan 15, 1974 197019801990200020102020

Crests at or above flood stage, by decade

Crests at or above flood stage per decade, Long Tom River at Monroe 1960s: 1 1970s: 3 3 1980s: 2 1990s: 3 2000s: 1 2010s: 1 1960s1970s1980s1990s2000s2010s
  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, Long Tom River at Monroe
1Jan 15, 197410.42+1.42Minor10,500
2Feb 7, 199610.08+1.08Minor9,560
3Dec 26, 196410.06+1.06Minor9,520
4Jan 21, 19729.59+0.59Minor7,920
5Jan 18, 20069.54+0.54Minor8,138
6Dec 6, 19819.47+0.47Minor7,990
7Dec 28, 19989.33+0.33Minor7,610
8Feb 22, 19869.17+0.17Minor7,260
9Apr 9, 20199.11+0.11Minor7,039
10Nov 19, 19969.04+0.04Minor6,940
11Jan 26, 19709.03+0.03Minor7,190
12Jan 19, 20128.93−0.07Action6,620
13Jan 14, 19888.87−0.13Action6,530

Other gauges in Benton County

Flood gauges in Benton County
Philomath20.021.53 ft, Jan 19, 20121
Corvallis30.042.40 ft, Dec 1, 18616

Benton County: every hazard · River floods across the country · Oregon

NOAA National Water Prediction Service, gauge MNRO3, 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.