River gauges›New Hampshire
RIVER GAUGE · MERRIMACK RIVER

Merrimack River at Nashua

Hillsborough County, New Hampshire

Water level4.71 ft
Flow2,920 cfs
Last readingSep 16, 2026, 5:15 PM UTC (last recorded)
Action16 ft
Minor flood18 ft
Moderate flood26 ft
Major flood35 ft

The past week

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What floods at each level

Highest crests on record

DateLevelFlow
Mar 19, 193641.3 ft—
Sep 22, 193830.5 ft—
May 15, 200626 ft—

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