Souhegan River at Merrimack, NH
USGS Site No: 01094000 • Souhegan River • Hillsborough County, NH
Souhegan River at Merrimack, NH on the Souhegan River is currently at 180 cfs (Normal — 65th percentile for this date) . Gage height: 2.99 ft.
Reading from
Historical Percentile Comparison
Today's discharge compared to the long-term record for October 28 at this station. Percentile rank shows what fraction of historical years had lower flow on this date.
| Percentile | Label | CFS Threshold | Today's Flow |
|---|---|---|---|
| 10th | Very Low threshold | 25 | |
| 25th | Low threshold | 45 | |
| 50th (Median) | Normal (median) | 94 | |
| 75th | High threshold | 234 | Today: 180 cfs |
| 95th | Very High threshold | 575 |
30-Day Hydrograph
Recent discharge plotted against the historical 10th–95th percentile envelope for the same calendar days. Source: USGS daily values + long-term statistics.
30-Day Flow History
| Date | Discharge (CFS) | Gage Ht (ft) |
|---|---|---|
| May 28, 2026 | 199 | — |
| May 27, 2026 | 243 | — |
| May 26, 2026 | 312 | — |
| May 25, 2026 | 224 | — |
| May 24, 2026 | 141 | — |
| May 23, 2026 | 156 | — |
| May 22, 2026 | 193 | — |
| May 21, 2026 | 223 | — |
| May 20, 2026 | 256 | — |
| May 19, 2026 | 303 | — |
| May 18, 2026 | 366 | — |
| May 17, 2026 | 472 | — |
| May 16, 2026 | 644 | — |
| May 15, 2026 | 816 | — |
| Apr 21, 2026 | 251 | — |
| Apr 20, 2026 | 271 | — |
| Apr 19, 2026 | 283 | — |
| Apr 18, 2026 | 314 | — |
| Apr 17, 2026 | 319 | — |
| Apr 16, 2026 | 320 | — |
| Apr 15, 2026 | 314 | — |
| Apr 14, 2026 | 245 | — |
| Apr 13, 2026 | 250 | — |
| Apr 12, 2026 | 272 | — |
| Apr 11, 2026 | 302 | — |
| Apr 10, 2026 | 329 | — |
| Apr 9, 2026 | 366 | — |
| Apr 8, 2026 | 399 | — |
| Apr 7, 2026 | 430 | — |
| Apr 6, 2026 | 494 | — |
Station Information
- USGS Site No
- 01094000
- State
- NH
- County
- Hillsborough County
- Coordinates
- 42.8576, -71.5062
- Drainage Area
- 171 mi²
- Datum (ft)
- 159.9
- HUC Code
- 01070002
Flood Stage Thresholds
- Action Stage
- 8.0 ft
- Flood Stage
- 9.0 ft
- Moderate Flood
- 11.0 ft
- Major Flood
- 13.0 ft
Currently 6.01 ft below flood stage.
Recent Extremes
- Max discharge
-
3,220 cfsMay 11, 2025
- Min discharge
-
17 cfsSep 23, 2025
- Days at flood stage
- 0
Computed from the local daily-values archive.
Nearby Gauges
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Nashua River at East Pepperell, MANormal13.6 mi · 282 cfs
-
Squannacook River Near West Groton, MANormal17.2 mi · 62 cfs
-
Merrimack River below Concord River at Lowell, MAHigh18.0 mi · 7,160 cfs
-
Concord River Below River Meadow Brook, at Lowell, MANormal18.4 mi · 323 cfs
-
Shawsheen River at Balmoral Street at Andover, MANormal22.2 mi · 44 cfs