Search
Menu

Explore

Hazards

Analysis

Rankings

Reference

Upper Ammonoosuc River near Groveton

Highest listed crest 12.01 ftFlood stage 7.5 ft9 crests since 1953

The Upper Ammonoosuc River near Groveton crested at major flood stage 1 time among the 9 crests the National Weather Service lists from 1953 to 2023. The highest, 12.01 ft on May 20, 1969, was major flooding, 4.51 feet above flood stage.

The gauge

Highest listed crest
12.01 ft
May 20, 1969; 24,100 cubic feet per second
Flood stage
7.5 ft
Major flooding from 10.0 ft
Crests at major
1
20th of 34 gauges in New Hampshire
Most recent flood crest
April 21, 2019
8.64 ft, minor flooding
Location
Coos County
New Hampshire

Flood stages

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

Flood categories, Upper Ammonoosuc River near Groveton
Action stage6.51Dec 28, 2023The level at which the NWS or its partners begin to take action
Flood stage (minor)7.55Apr 21, 2019Minimal or no property damage, but possibly some public threat
Moderate flood stage9.02Apr 23, 1954Some inundation of structures and roads near the stream
Major flood stage10.01May 20, 1969Extensive inundation of structures and roads

Every listed crest

9 crests from 1953 to 2023. Filled: at or above flood stage. Hover a crest for its date and stage.

Listed crests at the Upper Ammonoosuc River near Groveton, 1953 to 2023 68101214ft Flood stage 7.5 ftMajor 10.0 ft Mar 27, 1953: 9.44 ft, moderate flooding; 9,950 cubic feet per secondApr 23, 1954: 9.01 ft, moderate flooding; 8,880 cubic feet per secondMay 20, 1969: 12.01 ft, major flooding; 24,100 cubic feet per secondApr 24, 1996: 8.64 ft, minor flooding; 8,280 cubic feet per secondMar 31, 1998: 8.97 ft, minor flooding; 9,130 cubic feet per secondApr 14, 2002: 8.91 ft, minor flooding; 9,960 cubic feet per secondApr 15, 2014: 8.78 ft, minor flooding; 8,960 cubic feet per secondApr 21, 2019: 8.64 ft, minor flooding; 8,620 cubic feet per secondDec 28, 2023: 6.96 ft, action stage; 5,100 cubic feet per second Highest, 12.01 ft, May 20, 1969 1960197019801990200020102020

Crests at or above flood stage, by decade

Crests at or above flood stage per decade, Upper Ammonoosuc River near Groveton 1950s: 2 2 1960s: 1 1970s: 0 1980s: 0 1990s: 2 2000s: 1 2010s: 2 2020s: 0 1950s1960s1970s1980s1990s2000s2010s2020s
  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, Upper Ammonoosuc River near Groveton
1May 20, 196912.01+4.51Major24,100
2Mar 27, 19539.44+1.94Moderate9,950
3Apr 23, 19549.01+1.51Moderate8,880
4Mar 31, 19988.97+1.47Minor9,130
5Apr 14, 20028.91+1.41Minor9,960
6Apr 15, 20148.78+1.28Minor8,960
7Apr 24, 19968.64+1.14Minor8,280
8Apr 21, 20198.64+1.14Minor8,620
9Dec 28, 20236.96−0.54Action5,100

Other gauges in Coos County

Flood gauges in Coos County
Gorham8.010.30 ft, Apr 30, 19230
Dalton18.025.60 ft, Mar 20, 19363
North Stratford13.016.66 ft, Mar 13, 19360

Coos County: every hazard · River floods across the country · New Hampshire

NOAA National Water Prediction Service, gauge GRUN3, 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.