Summary
Total streamflow across the
Merrimack River
was last observed at
23,310
cfs, and is expected to yield approximately
46,235
acre-ft of water today; about 105%
of normal.
Average streamflow for this time of year is
22,101 cfs,
with recent peaks last observed
on
2023-12-20 when daily discharge volume was observed at
88,890 cfs.
Maximum discharge along the river is currently at the
Merrimack River Bl Concord River At Lowell
reporting a streamflow rate of 12,100 cfs.
This is also the highest stage along the Merrimack River, with a gauge stage of
45.43 ft at this location.
This river is monitored from 3 different streamgauging stations along the Merrimack River, the highest being situated at an altitude of 269 ft, the
Merrimack River At Franklin Junction.
15-Day Weather Outlook
River Details
| Last Updated | 2026-03-25 |
| Discharge Volume | 46,235 ACRE-FT |
| Streamflow |
23,310.0 cfs
-2260.0 cfs (-8.84%) |
| Percent of Normal | 105.47% |
| Maximum |
88,890.0 cfs
2023-12-20 |
| Seasonal Avg | 22,101 cfs |
River Streamflow Levels
| Streamgauge | Streamflow | Gauge Stage | 24hr Change (%) | % Normal | Minimum (cfs) | Maximum (cfs) | Air Temp | Elevation |
|---|---|---|---|---|---|---|---|---|
|
Merrimack River At Franklin Junction
USGS 01081500 |
3310 cfs | 6.34 ft | -9.07 | |||||
|
Merrimack R Nr Goffs Falls
USGS 01092000 |
7900 cfs | 5.97 ft | -9.51 | |||||
|
Merrimack River Bl Concord River At Lowell
USGS 01100000 |
12100 cfs | 45.43 ft | -8.33 |
Seasonal Discharge Comparison
Maximum Streamflow Discharge
Streamflow Elevation Profile
The Merrimack River (or Merrimac River, an occasional earlier spelling) is a 117-mile-long (188 km) river in the northeastern United States. It rises at the confluence of the Pemigewasset and Winnipesaukee rivers in Franklin, New Hampshire, flows southward into Massachusetts, and then flows northeast until it empties into the Gulf of Maine at Newburyport. From Pawtucket Falls in Lowell, Massachusetts, onward, the Massachusetts–New Hampshire border is roughly calculated as the line three miles north of the river.
The Merrimack is an important regional focus in both New Hampshire and Massachusetts. The central-southern part of New Hampshire and most of northeast Massachusetts is known as the Merrimack Valley.
Several U.S. naval ships have been named USS Merrimack and USS Merrimac in honor of this river. The river is perhaps best known for the early American literary classic A Week on the Concord and Merrimack Rivers by Henry David Thoreau.