Upper Ammonoosuc River near Groveton, NH
River level and flood forecast · Coos County
The river is 5.7 ft below flood stage (7.5 ft).
Flow: 62 cubic feet per second (USGS).
Much lower than normal for October 13.
Usual for October 13: 112 to 310 cubic feet per second (the middle half of 80 years).
The last 7 days and the forecast
NWS forecast issued Sun, Dec 31, 7 PM. Forecasts change as rain falls and as upstream water arrives.
Get flood alerts for this river
An email when the National Weather Service forecasts Upper Ammonoosuc River near Groveton to flood, when it floods, and when it's over.
Flood stages
| Major flood stage | 10 ft |
| Moderate flood stage | 9 ft |
| Flood stage | 7.5 ft |
| Action stage | 6.5 ft |
| Record crest (May 20, 1969) | 12.01 ft |
What floods at each level
From the National Weather Service, highest first.
- 10 ftMajor flooding occurs. Homes on Brooklyn Street flooded in Groveton. Water up to homes off West Street.
- 9.5 ftCumberland Road and Northside Road flooded in numerous places in Groveton.
- 9 ftModerate flooding occurs. Non-residential properties off West Street inundated. Water up to Winter Street and Route 110 in Groveton.
- 8.5 ftIn Stark, water is up to properties on Corkum Road and Northside Roads.
- 8 ftWater up to Cumberland Street or Northside Road in Northumberland. Northside Road in Stark flooded.
- 7.5 ftMinor floooding occurs. Mechanics Street inundated along industrial areas in Groveton. Water encroaching on properties on Brooklyn Street and Mountain View Avenue.
- 6 ftRiver at bankfull.
Highest crests on record
- 12.01 ft — May 20, 1969
- 9.44 ft — March 27, 1953
- 9.01 ft — April 23, 1954
- 8.97 ft — March 31, 1998
- 8.91 ft — April 14, 2002
Recent crests: 6.96 ft (December 28, 2023) · 8.64 ft (April 21, 2019) · 8.78 ft (April 15, 2014) · 8.91 ft (April 14, 2002) · 8.97 ft (March 31, 1998)
Highest flow on record
24,100 cubic feet per second — May 20, 1969. From the USGS's yearly peaks since 1941.
Up and down the river, and nearby
Not an official source. River levels, forecasts, flood stages and impacts are from the National Weather Service (GRUN3); flow from the U.S. Geological Survey. Readings are provisional. In a flood, follow your local officials and the NWS at weather.gov.