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Tualatin River near Dilley

Highest listed crest 19.27 ftFlood stage 17.5 ft34 crests since 1949

The Tualatin River near Dilley crested above flood stage 33 times among the 34 crests the National Weather Service lists from 1949 to 2025. The highest, 19.27 ft on January 21, 1972, was moderate flooding, 1.77 feet above flood stage. 1 other gauge on the Tualatin River crested above flood stage within a week of it.

The gauge

Highest listed crest
19.27 ft
January 21, 1972; 11,600 cubic feet per second
Flood stage
17.5 ft
Major flooding from 19.5 ft
Crests at major
0
33 above flood stage
Most recent flood crest
December 19, 2025
17.79 ft, minor flooding
Location
Washington County
Near Forest Grove (3.5 mi), Cornelius (4.7 mi), Hillsboro (9.9 mi)

Flood stages

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

Flood categories, Tualatin River near Dilley
Action stage16.01Jan 9, 2009The level at which the NWS or its partners begin to take action
Flood stage (minor)17.527Dec 19, 2025Minimal or no property damage, but possibly some public threat
Moderate flood stage18.56Dec 5, 2007Some inundation of structures and roads near the stream
Major flood stage19.50—Extensive inundation of structures and roads

Every listed crest

34 crests from 1949 to 2025. Filled: at or above flood stage. Hover a crest for its date and stage.

Listed crests at the Tualatin River near Dilley, 1949 to 2025 1717.51818.51919.5ft Flood stage 17.5 ftMajor 19.5 ft Feb 17, 1949: 17.90 ft, minor floodingDec 22, 1955: 18.80 ft, moderate floodingNov 26, 1962: 18.00 ft, minor floodingJan 27, 1970: 17.53 ft, minor flooding; 3,940 cubic feet per secondJan 17, 1971: 17.91 ft, minor flooding; 4,440 cubic feet per secondJan 21, 1972: 19.27 ft, moderate flooding; 11,600 cubic feet per secondJan 16, 1974: 18.53 ft, moderate flooding; 11,500 cubic feet per secondDec 14, 1977: 18.63 ft, moderate flooding; 6,550 cubic feet per secondDec 26, 1980: 18.20 ft, minor flooding; 4,190 cubic feet per secondFeb 20, 1982: 17.93 ft, minor flooding; 4,030 cubic feet per secondDec 16, 1982: 17.86 ft, minor flooding; 3,080 cubic feet per secondFeb 1, 1987: 18.19 ft, minor flooding; 3,490 cubic feet per secondJan 15, 1988: 18.14 ft, minor flooding; 3,990 cubic feet per secondJan 10, 1990: 17.76 ft, minor flooding; 2,850 cubic feet per secondApr 5, 1991: 18.47 ft, minor flooding; 6,230 cubic feet per secondDec 27, 1994: 17.72 ft, minor flooding; 2,750 cubic feet per secondFeb 8, 1996: 19.06 ft, moderate flooding; 10,100 cubic feet per secondDec 30, 1996: 18.02 ft, minor flooding; 4,050 cubic feet per secondJan 14, 1998: 17.72 ft, minor flooding; 2,550 cubic feet per secondNov 26, 1998: 18.00 ft, minor flooding; 3,980 cubic feet per secondDec 29, 1998: 17.99 ft, minor flooding; 3,890 cubic feet per secondDec 16, 1999: 17.75 ft, minor flooding; 3,160 cubic feet per secondJan 8, 2002: 17.80 ft, minor flooding; 3,800 cubic feet per secondFeb 1, 2003: 17.74 ft, minor flooding; 3,135 cubic feet per secondJan 30, 2004: 17.68 ft, minor flooding; 2,956 cubic feet per secondDec 31, 2005: 17.69 ft, minor flooding; 3,002 cubic feet per secondJan 11, 2006: 17.88 ft, minor flooding; 3,561 cubic feet per secondDec 5, 2007: 19.00 ft, moderate flooding; 9,700 cubic feet per secondJan 2, 2009: 17.88 ft, minor flooding; 3,560 cubic feet per secondJan 9, 2009: 17.48 ft, action stage; 2,460 cubic feet per secondMar 30, 2012: 17.57 ft, minor flooding; 2,675 cubic feet per secondDec 9, 2015: 17.93 ft, minor flooding; 3,560 cubic feet per secondNov 25, 2016: 17.67 ft, minor flooding; 2,935 cubic feet per secondDec 19, 2025: 17.79 ft, minor flooding; 3,280 cubic feet per second Highest, 19.27 ft, Jan 21, 1972 19501960197019801990200020102020

Crests at or above flood stage, by decade

Crests at or above flood stage per decade, Tualatin River near Dilley 1940s: 1 1950s: 1 1960s: 1 1970s: 5 1980s: 5 1990s: 9 9 2000s: 7 2010s: 3 2020s: 1 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.
  3. 2 crests measured on an earlier gauge datum are left out: 19.34 ft on Dec 22, 1964; 18.42 ft on Dec 13, 1966.

Highest crests

Highest listed crests, Tualatin River near Dilley
1Jan 21, 197219.27+1.77Moderate11,600
2Feb 8, 199619.06+1.56Moderate10,100
3Dec 5, 200719.00+1.50Moderate9,700
4Dec 22, 195518.80+1.30Moderate—
5Dec 14, 197718.63+1.13Moderate6,550
6Jan 16, 197418.53+1.03Moderate11,500
7Apr 5, 199118.47+0.97Minor6,230
8Dec 26, 198018.20+0.70Minor4,190
9Feb 1, 198718.19+0.69Minor3,490
10Jan 15, 198818.14+0.64Minor3,990
11Dec 30, 199618.02+0.52Minor4,050
12Nov 26, 196218.00+0.50Minor—
13Nov 26, 199818.00+0.50Minor3,980
14Dec 29, 199817.99+0.49Minor3,890
15Feb 20, 198217.93+0.43Minor4,030
16Dec 9, 201517.93+0.43Minor3,560
17Jan 17, 197117.91+0.41Minor4,440
18Feb 17, 194917.90+0.40Minor—
19Jan 11, 200617.88+0.38Minor3,561
20Jan 2, 200917.88+0.38Minor3,560
21Dec 16, 198217.86+0.36Minor3,080
22Jan 8, 200217.80+0.30Minor3,800
23Dec 19, 202517.79+0.29Minor3,280
24Jan 10, 199017.76+0.26Minor2,850
25Dec 16, 199917.75+0.25Minor3,160
26Feb 1, 200317.74+0.24Minor3,135
27Dec 27, 199417.72+0.22Minor2,750
28Jan 14, 199817.72+0.22Minor2,550
29Dec 31, 200517.69+0.19Minor3,002
30Jan 30, 200417.68+0.18Minor2,956
31Nov 25, 201617.67+0.17Minor2,935
32Mar 30, 201217.57+0.07Minor2,675
33Jan 27, 197017.53+0.03Minor3,940
34Jan 9, 200917.48−0.02Action2,460

The worst floods along the Tualatin River

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

January 21, 1972: 19.27 ft here, moderate flooding

  • West LinnOR · Jan 24, 1972 · 14.18 ft · Minor

February 8, 1996: 19.06 ft here, moderate flooding

  • FarmingtonOR · Feb 9, 1996 · 37.20 ft · Major · its highest
  • West LinnOR · Feb 10, 1996 · 18.32 ft · Major · its highest

December 5, 2007: 19.00 ft here, moderate flooding

Gauges on the Tualatin River

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

Flood gauges on the Tualatin River
Dilley this gaugeOR17.519.27 ft, Jan 21, 19720
FarmingtonOR32.037.20 ft, Feb 9, 19963
West LinnOR13.518.32 ft, Feb 10, 19965

Other gauges in Washington County

Flood gauges in Washington County
Durham9.111.78 ft, Dec 7, 20150
Forest Grove16.517.05 ft, Dec 19, 20250
Farmington32.037.20 ft, Feb 9, 19963

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

NOAA National Water Prediction Service, gauge DLLO3, 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.