Flatlick Branch Above Frog Branch at Chantilly, VA
USGS Site No: 01656903 • Flatlick Branch • Fairfax County, VA
Flatlick Branch Above Frog Branch at Chantilly, VA on the Flatlick Branch is currently at 2 cfs (Normal — 50th percentile for this date) . Gage height: 1.12 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 | 1 | |
| 25th | Low threshold | 1 | |
| 50th (Median) | Normal (median) | 2 | |
| 75th | High threshold | 16 | Today: 2 cfs |
| 95th | Very High threshold | 0 |
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 | 4 | — |
| May 27, 2026 | 5 | — |
| May 26, 2026 | 7 | — |
| May 25, 2026 | 11 | — |
| May 24, 2026 | 82 | — |
| May 23, 2026 | 16 | — |
| May 22, 2026 | 11 | — |
| May 21, 2026 | 4 | — |
| May 20, 2026 | 1 | — |
| May 19, 2026 | 2 | — |
| May 18, 2026 | 1 | — |
| May 17, 2026 | 1 | — |
| May 16, 2026 | 1 | — |
| May 15, 2026 | 1 | — |
| Apr 21, 2026 | 1 | — |
| Apr 20, 2026 | 1 | — |
| Apr 19, 2026 | 1 | — |
| Apr 18, 2026 | 1 | — |
| Apr 17, 2026 | 1 | — |
| Apr 16, 2026 | 1 | — |
| Apr 15, 2026 | 1 | — |
| Apr 14, 2026 | 1 | — |
| Apr 13, 2026 | 1 | — |
| Apr 12, 2026 | 1 | — |
| Apr 11, 2026 | 1 | — |
| Apr 10, 2026 | 2 | — |
| Apr 9, 2026 | 2 | — |
| Apr 8, 2026 | 2 | — |
| Apr 7, 2026 | 3 | — |
| Apr 6, 2026 | 4 | — |
Station Information
- USGS Site No
- 01656903
- State
- VA
- County
- Fairfax County
- Coordinates
- 38.8824, -77.4319
- Drainage Area
- 4 mi²
- Datum (ft)
- 256.8
- HUC Code
- 02070010
Flood Stage Thresholds
- Action Stage
- 6.0 ft
- Flood Stage
- 9.0 ft
- Moderate Flood
- 10.0 ft
- Major Flood
- 15.0 ft
Currently 7.88 ft below flood stage.
Recent Extremes
- Max discharge
-
211 cfsJun 15, 2025
- Min discharge
-
0 cfsOct 6, 2025
- Days at flood stage
- 0
Computed from the local daily-values archive.
Nearby Gauges
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Fourmile Run at Alexandria, VALow18.8 mi · 4 cfs
-
Potomac River at Point Of Rocks, MDVery High27.7 mi · 34,600 cfs
-
Hawlings River Near Sandy Spring, MDLow29.9 mi · 11 cfs
-
Patuxent River Below Brighton Dam Near Brighton MDVery Low31.4 mi · 12 cfs
-
Patuxent River Near Unity, MDNormal31.8 mi · 24 cfs