Merrimack River Below Concord River At Lowell flow report
As of July 15, 2026, Merrimack River Below Concord River At Lowell is flowing at 1,710 cfs with a gage height of 41.88 ft, receding 12% over the past 24 hours. Source: USGS gauge #01100000, refreshed throughout the day.
Historical Data
Merrimack River Below Concord River At Lowell at a glance
How Merrimack River Below Concord River At Lowell is running right now, where it sits on the map, and the key gauge stats.
Merrimack River Below Concord River At Lowell is flowing at 1,710 cfs, with the water sitting 41.88 ft at the gage. Flow is down 12% since yesterday as the gauge recedes.
This is USGS gauge #01100000 in Massachusetts. Over the past 10 days the average has been 2,857 cfs, peaking at 3,660 cfs.
For real-time updates and historical context, see the realtime view or the historical comparison. Browse other gauges in the Massachusetts flow report.
Engineering Data
Flow-duration statistics and observed peak-flow context computed from this gauge’s complete daily record (USGS #01100000).
Percentiles are flow-duration values computed from this gauge’s observed daily record as archived by Snoflo. Return periods are Weibull plotting-position estimates from observed annual maxima, provided as general reference context only. Always verify against official USGS NWIS records. Part of Snoflo for Engineering.
Streamflow Forecast
Over the next 5 days, Merrimack River Bl Concord River At Lowell is expected to hold near today's 1710 cfs, toward roughly 1614 cfs by 2026-07-20 (likely range 548-4753 cfs) -- running well below the seasonal normal.
Powered by PULSE — Snoflo’s forecast engine, trained on this gauge’s full record of storms, snowmelt, and dry spells.
| Date | Expected (p50) | Likely range (p25–p75) | vs normal | Projected stage |
|---|
How does this compare to past years?
Year-over-year overlay, annual peak discharge, the full distribution of daily flows on record, and the gauge's rating curve.
Weather Forecast
Next 5 days, hour by hour
Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.
5-day forecast table
Every 3 hours, broken out across temperature, snow, rain, humidity, and wind.
| Time | Condition | Temp (°F) | Snow (in) | Rain (in) | Humidity (%) | Wind (mps) | Wind dir |
|---|---|---|---|---|---|---|---|
| Loading detailed forecast… | |||||||
15-day forecast
Daily temperatures, snow, and rain projected over the next two weeks.
Merrimack River Below Concord River At Lowell
The primary flow providers are snowmelt and rainfall, and the river is regulated by several dams, including the Lowell Dam. Seasonally, the river experiences high flow during the spring snowmelt and wet periods, while low flow occurs during hot, dry summers. Interesting facts include the Merrimack River's historic significance as a major transportation route during the Industrial Revolution and the occasional presence of American shad, a migratory fish species that spawns in the river.
Nearby streamflow levels
Cross-check Merrimack River Below Concord River At Lowell's discharge against nearby gauges to spot whether the change here is local or regional.
| Gauge | Streamflow |
|---|---|
| Merrimack River Bl Concord River At Lowell | 1,710 cfs |
| Concord R Below R Meadow Brook | 157 cfs |
| Shawsheen River Near Wilmington | 14 cfs |
| Spicket River Near Methuen | 1 cfs |
| Beaver Brook At North Pelham | 5 cfs |
| Nashoba Brook Near Acton | 2 cfs |
Nearby snowpack data
Snowpack at SNOTEL stations near Merrimack River Below Concord River At Lowell. Spring snowmelt is the dominant driver of streamflow in mountain basins -- a deep snowpack upstream means more runoff later in the season.
| SNOTEL station | Snowpack |
|---|---|
| Lowell 2.6 Ene | 0 in |
| Lowell | 0 in |
| Tewksbury 3.6 Sse | 0 in |
| Andover 0.6 E | 0 in |
| Carlisle 2.0 Se | 0 in |
| North Andover 0.3 Nw | 0 in |
River levels & flood safety
- Read the level before you go
- A river that's runnable at one flow can be deadly at another. Check current discharge and gage height — like the values shown above — against the flood-stage thresholds, and remember levels can spike fast after rain or a dam release.
- Respect cold water
- Snowmelt rivers run cold even in summer. Sudden immersion triggers cold-water shock and saps strength within minutes. Wear a PFD, dress for the water temperature (not the air), and never wade or paddle alone.
- Watch for swiftwater hazards
- Strainers (downed trees), undercut rocks, and low-head dams are the deadliest features on moving water. High, fast, muddy water hides them. If in doubt, scout from shore and portage.
- Mind flash floods & releases
- Narrow canyons can flood from a storm miles upstream, and dam-controlled reaches can rise without warning. Know the forecast, the release schedule, and your exit before you launch.
Track Merrimack River Below Concord River At Lowell in the Snoflo app
Save this gauge as a favorite, set push alerts when streamflow crosses a threshold (e.g. "alert me when Merrimack River Below Concord River At Lowell crosses 5,000 cfs"), and Snoflo's iOS app will push the moment USGS reports the crossing.
About Merrimack River Below Concord River At Lowell
Where does the streamflow data for Merrimack River Below Concord River At Lowell come from?
Discharge, gage height, and water temperature come directly from the USGS streamflow gauge 01100000. Snoflo refreshes the time series throughout the day. Forecasts come from the NOAA / yr.no feed Snoflo's iOS app uses.
How often is the report updated?
USGS gauges report continuously (typically every 15 minutes). Snoflo pulls fresh values throughout the day — look for the "as of" timestamp on the streamflow hero card.
What's the difference between discharge and gage height?
Discharge (cubic feet per second, or cfs) is the volume of water flowing past the gauge each second. Gage height is how high the water sits at the gauge (feet). They're related by a rating curve specific to each gauge — higher water means more flow, but the exact ratio depends on channel shape.
How is "percent of median" calculated?
Today's discharge is compared to the historical median discharge on this calendar day across the gauge's full record. 100% = right on median; 200% = a very high year; 30% = a drought-level low.
What are flood stages, and is this river safe right now?
Flood stages are NWS-defined gage-height thresholds — Action, Minor, Moderate, Major — marking when nearby roads or floodplains start to be affected. "Safe" depends on your activity and skill: a level that's a fun paddle for an expert can be lethal for a wader. Always check the current level against the thresholds above and the safety links, and when in doubt, stay off the water.
Can I get alerts when Merrimack River Below Concord River At Lowell rises?
Yes — flow alerts are managed in the Snoflo iOS app. Favorite this gauge, set a streamflow threshold (e.g. "alert me when discharge crosses 5,000 cfs"), and you'll get a push the moment USGS reports the crossing.
Access the free Merrimack River Below Concord River At Lowell report
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