Search
Menu

Explore

Hazards

Analysis

Rankings

Reference

Farmington River at Unionville

Highest listed crest 18.55 ftFlood stage 12.0 ft30 crests since 1978

The Farmington River at Unionville crested above flood stage 21 times among the 30 crests the National Weather Service lists from 1978 to 2024. The highest, 18.55 ft on August 28, 2011, was moderate flooding, 6.55 feet above flood stage. 3 other gauges on the Farmington River crested above flood stage within a week of it.

The gauge

Highest listed crest
18.55 ft
August 28, 2011; 26,600 cubic feet per second
Flood stage
12.0 ft
Major flooding from 20.0 ft
Crests at major
0
21 above flood stage
Most recent flood crest
January 10, 2024
12.57 ft, minor flooding
Location
Hartford County
Near Bristol (5.8 mi), New Britain (7.5 mi), Hartford (10.6 mi)

Flood stages

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

Flood categories, Farmington River at Unionville
Action stage10.09Mar 30, 2010The level at which the NWS or its partners begin to take action
Flood stage (minor)12.014Jan 10, 2024Minimal or no property damage, but possibly some public threat
Moderate flood stage14.07Sep 2, 2021Some inundation of structures and roads near the stream
Major flood stage20.00—Extensive inundation of structures and roads

Every listed crest

30 crests from 1978 to 2024. Filled: at or above flood stage. Hover a crest for its date and stage.

Listed crests at the Farmington River at Unionville, 1978 to 2024 101214161820ft Flood stage 12.0 ftMajor 20.0 ft Jan 9, 1978: 12.75 ft, minor flooding; 10,500 cubic feet per secondMar 6, 1979: 11.99 ft, action stage; 8,980 cubic feet per secondMar 23, 1980: 16.57 ft, moderate flooding; 20,300 cubic feet per secondFeb 20, 1981: 12.33 ft, minor flooding; 9,660 cubic feet per secondJun 6, 1982: 13.85 ft, minor flooding; 12,800 cubic feet per secondApr 20, 1983: 12.52 ft, minor flooding; 10,000 cubic feet per secondMay 30, 1984: 13.32 ft, minor flooding; 11,700 cubic feet per secondSep 27, 1985: 11.83 ft, action stage; 8,640 cubic feet per secondApr 5, 1987: 15.52 ft, moderate flooding; 17,100 cubic feet per secondMay 11, 1989: 10.10 ft, action stage; 5,220 cubic feet per secondOct 20, 1989: 12.67 ft, minor flooding; 10,200 cubic feet per secondOct 24, 1990: 11.42 ft, action stage; 7,620 cubic feet per secondJun 6, 1992: 11.76 ft, action stageJan 27, 1996: 13.37 ft, minor flooding; 11,700 cubic feet per secondDec 2, 1996: 11.21 ft, action stage; 7,420 cubic feet per secondSep 17, 1999: 13.10 ft, minor flooding; 10,200 cubic feet per secondOct 15, 2005: 14.63 ft, moderate flooding; 16,200 cubic feet per secondMay 13, 2006: 12.43 ft, minor flooding; 9,803 cubic feet per secondApr 16, 2007: 16.81 ft, moderate flooding; 21,000 cubic feet per secondMar 8, 2008: 11.85 ft, action stage; 8,780 cubic feet per secondDec 12, 2008: 11.21 ft, action stage; 7,420 cubic feet per secondMar 30, 2010: 11.66 ft, action stage; 8,350 cubic feet per secondMar 7, 2011: 15.61 ft, moderate flooding; 17,500 cubic feet per secondMar 11, 2011: 12.15 ft, minor flooding; 9,483 cubic feet per secondAug 28, 2011: 18.55 ft, moderate flooding; 26,600 cubic feet per secondSep 8, 2011: 12.77 ft, minor flooding; 11,048 cubic feet per secondSep 2, 2021: 14.01 ft, moderate flooding; 13,105 cubic feet per secondSep 29, 2023: 12.87 ft, minor flooding; 10,495 cubic feet per secondDec 18, 2023: 13.28 ft, minor flooding; 11,397 cubic feet per secondJan 10, 2024: 12.57 ft, minor flooding; 9,858 cubic feet per second Highest, 18.55 ft, Aug 28, 2011 19801990200020102020

Crests at or above flood stage, by decade

Crests at or above flood stage per decade, Farmington River at Unionville 1970s: 1 1980s: 7 7 1990s: 2 2000s: 3 2010s: 4 2020s: 4 1970s1980s1990s2000s2010s2020s
  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. 1 crest measured on an earlier gauge datum is left out: 32.90 ft on Aug 19, 1955.

Highest crests

Highest listed crests, Farmington River at Unionville
1Aug 28, 201118.55+6.55Moderate26,600
2Apr 16, 200716.81+4.81Moderate21,000
3Mar 23, 198016.57+4.57Moderate20,300
4Mar 7, 201115.61+3.61Moderate17,500
5Apr 5, 198715.52+3.52Moderate17,100
6Oct 15, 200514.63+2.63Moderate16,200
7Sep 2, 202114.01+2.01Moderate13,105
8Jun 6, 198213.85+1.85Minor12,800
9Jan 27, 199613.37+1.37Minor11,700
10May 30, 198413.32+1.32Minor11,700
11Dec 18, 202313.28+1.28Minor11,397
12Sep 17, 199913.10+1.10Minor10,200
13Sep 29, 202312.87+0.87Minor10,495
14Sep 8, 201112.77+0.77Minor11,048
15Jan 9, 197812.75+0.75Minor10,500
16Oct 20, 198912.67+0.67Minor10,200
17Jan 10, 202412.57+0.57Minor9,858
18Apr 20, 198312.52+0.52Minor10,000
19May 13, 200612.43+0.43Minor9,803
20Feb 20, 198112.33+0.33Minor9,660
21Mar 11, 201112.15+0.15Minor9,483
22Mar 6, 197911.99−0.01Action8,980
23Mar 8, 200811.85−0.15Action8,780
24Sep 27, 198511.83−0.17Action8,640
25Jun 6, 199211.76−0.24Action—
26Mar 30, 201011.66−0.34Action8,350
27Oct 24, 199011.42−0.58Action7,620
28Dec 2, 199611.21−0.79Action7,420
29Dec 12, 200811.21−0.79Action7,420
30May 11, 198910.10−1.90Action5,220

The worst floods along the Farmington River

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

August 28, 2011: 18.55 ft here, moderate flooding

April 16, 2007: 16.81 ft here, moderate flooding

March 23, 1980: 16.57 ft here, moderate flooding

  • SimsburyCT · Mar 22, 1980 · 16.00 ft · Moderate
  • TariffvilleCT · Mar 23, 1980 · 10.65 ft · Moderate

Gauges on the Farmington River

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

Flood gauges on the Farmington River
W. Br. Nr. New BostonMA8.014.06 ft, Aug 19, 19552
Unionville this gaugeCT12.018.55 ft, Aug 28, 20110
SimsburyCT12.030.10 ft, Aug 20, 19553
TariffvilleCT9.014.00 ft, Sep 22, 19381

Other gauges in Hartford County

Flood gauges in Hartford County
Broad Brook7.08.78 ft, Oct 15, 20050
Burlington7.09.33 ft, Oct 15, 20052
Hartford16.037.60 ft, Mar 21, 19367
Thompsonville15.026.60 ft, Mar 20, 19367
Simsbury12.030.10 ft, Aug 20, 19553
Tariffville9.014.00 ft, Sep 22, 19381
East Hartford9.013.78 ft, Sep 21, 19381
Hartford8.018.80 ft, Aug 19, 19551
Southington8.510.49 ft, Jan 10, 20240

Hartford County: every hazard · River floods across the country · Connecticut

NOAA National Water Prediction Service, gauge UNVC3, 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.