Potomac River at Point Of Rocks, MD
USGS Site No: 01638500 • Potomac River • Frederick County, MD
Potomac River at Point Of Rocks, MD on the Potomac River is currently at 34,600 cfs (Very High — 103th percentile for this date) . Gage height: 8.37 ft.
Reading from
Historical Percentile Comparison
Today's discharge compared to the long-term record for June 11 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 | 2,900 | |
| 25th | Low threshold | 3,860 | |
| 50th (Median) | Normal (median) | 6,110 | |
| 75th | High threshold | 8,620 | |
| 95th | Very High threshold | 19,600 |
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 | 29,600 | — |
| May 27, 2026 | 24,800 | — |
| May 26, 2026 | 26,000 | — |
| May 25, 2026 | 32,400 | — |
| May 24, 2026 | 28,000 | — |
| May 23, 2026 | 5,960 | — |
| May 22, 2026 | 3,400 | — |
| May 21, 2026 | 2,610 | — |
| May 20, 2026 | 2,580 | — |
| May 19, 2026 | 2,520 | — |
| May 18, 2026 | 2,580 | — |
| May 17, 2026 | 2,690 | — |
| May 16, 2026 | 2,720 | — |
| May 15, 2026 | 2,630 | — |
| Apr 21, 2026 | 3,810 | — |
| Apr 20, 2026 | 3,790 | — |
| Apr 19, 2026 | 3,880 | — |
| Apr 18, 2026 | 3,930 | — |
| Apr 17, 2026 | 4,180 | — |
| Apr 16, 2026 | 4,270 | — |
| Apr 15, 2026 | 4,490 | — |
| Apr 14, 2026 | 4,570 | — |
| Apr 13, 2026 | 4,840 | — |
| Apr 12, 2026 | 5,080 | — |
| Apr 11, 2026 | 5,430 | — |
| Apr 10, 2026 | 5,800 | — |
| Apr 9, 2026 | 6,140 | — |
| Apr 8, 2026 | 6,760 | — |
| Apr 7, 2026 | 6,900 | — |
| Apr 6, 2026 | 6,370 | — |
Station Information
- USGS Site No
- 01638500
- State
- MD
- County
- Frederick County
- Coordinates
- 39.2736, -77.5431
- Drainage Area
- 9,651 mi²
- Datum (ft)
- 199.9
- HUC Code
- 02070008
Flood Stage Thresholds
- Action Stage
- 11.0 ft
- Flood Stage
- 16.0 ft
- Moderate Flood
- 20.0 ft
- Major Flood
- 27.0 ft
Currently 7.63 ft below flood stage.
Recent Extremes
- Max discharge
-
145,000 cfsMay 15, 2025
- Min discharge
-
1,120 cfsDec 17, 2025
- Days at flood stage
- 0
Computed from the local daily-values archive.
Nearby Gauges
-
Patuxent River Near Unity, MDNormal26.2 mi · 24 cfs
-
Cattail Creek Near Glenwood, MDNormal26.4 mi · 17 cfs
-
Hawlings River Near Sandy Spring, MDLow28.8 mi · 11 cfs
-
Patuxent River Below Brighton Dam Near Brighton MDVery Low29.4 mi · 12 cfs
-
Morgan Run Near Louisville, MDNormal33.7 mi · 22 cfs