TidalMapDifficult Run above Fox Lake near Fairfax, VA Water Level Today
NWS river forecast
| When | Stage | Flow |
|---|
Forecast from the NOAA National Water Prediction Service. Issued a few times a day and only while a forecast is active. Not for navigation.
Last 30 days
About this gauge
USGS gauge 01645704 sits on Difficult Run and reads everything draining 5.5 square miles of the Middle Potomac-Catoctin basin. Its datum sits 288 feet above sea level NAVD88. Daily flow has been on record here since 2007, 19 years of it.
Where this gauge sits in the drainage
No gauged site sits above this one on the mainstem, so this is the first published reading on the river. Downstream the next reading comes from Difficult Run near Great Falls, VA at 58 square miles, so what passes this gauge is about 9% of the water measured there. Water passing here goes on to Potomac River near Wash, Dc Little Falls Pump Sta.
Normal flows here
Difficult Run runs a median of 3.9 cfs at this gauge across 19 years of record. May is the fullest month at a median 5.1 cfs, and September the leanest at 2.0 cfs. The highest daily mean on record is 854 cfs in 2008, and the lowest is 0.0 cfs in 2008.
| Month | Median flow | Share of annual median |
|---|---|---|
| Jan | 4.5 cfs | 115% |
| Feb | 4.7 cfs | 121% |
| Mar | 4.6 cfs | 118% |
| Apr | 4.8 cfs | 123% |
| May | 5.1 cfs | 131% |
| Jun | 3.9 cfs | 100% |
| Jul | 3.3 cfs | 85% |
| Aug | 2.7 cfs | 69% |
| Sep | 2.0 cfs | 51% |
| Oct | 2.5 cfs | 64% |
| Nov | 3.0 cfs | 78% |
| Dec | 4.2 cfs | 108% |
Medians from the USGS daily-statistics record, 2007 to 2026. A month at 100% is running at its own long-term median.
Nearby river gauges
- South Fork Little Difficult Run above Mouth near Vienna, VA
- Snakeden Branch above Lake Audubon at Reston, VA
- Long Branch at Olley Lane near Fairfax, VA
- Flatlick Branch above Frog Branch at Chantilly, VA
- Long Branch near Annandale, VA
- Difficult Run near Great Falls, VA
- Accotink Creek near Annandale, VA
- Tripps Run at Falls Church, VA
- Four Mile Run at Hwy 29 at Falls Church, VA
- Accotink Creek at Keene Mill Rd at Springfield, VA
- Dead Run at Whann Avenue near Mclean, VA
- Broad Run near Leesburg, VA
Live streamflow and gage height: USGS gauge 01645704. Percentile context computed against the gauge's period of record. Not for navigation.
Open Difficult Run above Fox Lake near Fairfax, VA on the live chart →
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