Merrimack River at Nashua
Flood levels
Official flood levels at this gauge: action stage begins at 16.0 ft; minor flooding begins at 18.0 ft; moderate flooding begins at 26.0 ft; major flooding begins at 35.0 ft.
| Action stage | 16.0 ft |
|---|---|
| Minor flooding | 18.0 ft |
| Moderate flooding | 26.0 ft |
| Major flooding | 35.0 ft |
Highest recorded crests
- 41.3 ft on Mar 20, 1936 (historic crest)
- 30.5 ft on Sep 23, 1938 (historic crest)
- 26.0 ft on May 15, 2006 (historic crest)
- 23.5 ft on Apr 17, 2007 (historic crest)
What the water does
National Weather Service impact statements for this gauge, in the Weather Service's own words.
| 18.0 ft | Flooding will begin in the lower lying sections of Hudson and Nashua as the river continues to climb above 18 feet. |
|---|---|
| 21.0 ft | Flooding will occur in low lying areas from Litchfield and Merrimack...to Hudson and Nashua. |
| 25.0 ft | The river has not reached this height since May 2006. This is a significant flood event. Follow the advice of local officials...evacuate if told to do so. |
| 28.0 ft | The river has not reached this height since the Hurricane of 1938. This is a serious flood event. Follow the advice of local officials...evacuate if told to do so. At this height...the Merrimack River is moving very swiftly. Stay away from the river. |
| 30.0 ft | This flood compares to the Hurricane of 1938 flood. This is a substantial flood event. Follow the directions of local officials...evacuate if told to do so. At this height the Merrimack River is moving very swiftly. Stay away from the river. |
| 35.0 ft | This is a major...life threatening flood event. The river has not reached this height since the Great New England flood of 1936. Major flooding will affect the communities of Merrimack and Litchfield through Nashua and Hudson. follow the advice of local officials...evacuate if told to do so. Stay away from the Merrimack River. |
| 40.0 ft | This is a disastrous...life threatening flood. This compares to the Great New England Flood of 1936. Follow the advice of local officials...and evacuate if told to do so. |
Forecast office: NWS Gray · River Forecast Center: Northeast River Forecast Center.
Merrimack River at Nashua in your pocket
Tidora puts this spot on your Home Screen and Lock Screen with free widgets, and sends free flood alerts before the water reaches the levels that matter to you. No account, no subscription needed for either.
Download Tidora on the App Store
Tidora is preparing for launch; these pages go fully live when the app ships.
Nearby stations and gauges
- Beaver Brook at North Pelham NWS gauge · 4.7 mi
- Souhegan River at Merrimack NWS gauge · 7.3 mi
- Nashua River at East Pepperell NWS gauge · 9.4 mi
- Merrimack River at Lowell NWS gauge · 10.9 mi
- Concord River at Lowell NWS gauge · 11.3 mi
- Spicket River near Methuen NWS gauge · 12.0 mi