Millstone River at Blackwells Mills NJ
USGS Site No: 01402000 • Millstone River • Somerset County, NJ
Millstone River at Blackwells Mills NJ on the Millstone River is currently at 157 cfs (Normal — 56th percentile for this date) . Gage height: 1.91 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 | 60 | |
| 25th | Low threshold | 80 | |
| 50th (Median) | Normal (median) | 132 | |
| 75th | High threshold | 235 | Today: 157 cfs |
| 95th | Very High threshold | 1,830 |
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 29, 2026 | 167 | — |
| May 28, 2026 | 201 | — |
| May 27, 2026 | 261 | — |
| May 26, 2026 | 401 | — |
| May 25, 2026 | 788 | — |
| May 24, 2026 | 618 | — |
| May 23, 2026 | 136 | — |
| May 22, 2026 | 146 | — |
| May 21, 2026 | 154 | — |
| May 20, 2026 | 106 | — |
| May 19, 2026 | 102 | — |
| May 18, 2026 | 119 | — |
| May 17, 2026 | 126 | — |
| May 16, 2026 | 133 | — |
| May 15, 2026 | 134 | — |
| Apr 21, 2026 | 94 | — |
| Apr 20, 2026 | 97 | — |
| Apr 19, 2026 | 100 | — |
| Apr 18, 2026 | 108 | — |
| Apr 17, 2026 | 115 | — |
| Apr 16, 2026 | 121 | — |
| Apr 15, 2026 | 127 | — |
| Apr 14, 2026 | 134 | — |
| Apr 13, 2026 | 133 | — |
| Apr 12, 2026 | 136 | — |
| Apr 11, 2026 | 140 | — |
| Apr 10, 2026 | 147 | — |
| Apr 9, 2026 | 159 | — |
| Apr 8, 2026 | 183 | — |
| Apr 7, 2026 | 229 | — |
Station Information
- USGS Site No
- 01402000
- State
- NJ
- County
- Somerset County
- Coordinates
- 40.4750, -74.5758
- Drainage Area
- 258 mi²
- Datum (ft)
- 25.9
- HUC Code
- 020301050312
Flood Stage Thresholds
- Action Stage
- 7.0 ft
- Flood Stage
- 9.0 ft
- Moderate Flood
- 10.0 ft
- Major Flood
- 15.0 ft
Currently 7.09 ft below flood stage.
Recent Extremes
- Max discharge
-
2,310 cfsMar 6, 2026
- Min discharge
-
71 cfsNov 21, 2025
- Days at flood stage
- 0
Computed from the local daily-values archive.
Nearby Gauges
-
Passaic River Near Millington NJNormal14.4 mi · 27 cfs
-
Robinsons Branch at Rahway NJNormal17.1 mi · 7 cfs
-
Robinsons Branch at Maple Ave at Rahway NJLow17.4 mi · 1 cfs
-
Rahway River at Rahway NJNormal18.3 mi · 17 cfs
-
Passaic River Near Chatham NJNormal19.9 mi · 68 cfs