Major Flood
15 ft
Current Water Level
Gage Height
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Streamflow
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Last Reading
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FLOOD STAGES
Know the flood categories.
Flood stages defined by the National Weather Service. Gage height data from USGS Water Resources.
Moderate Flood
10 ft
Minor Flood
9 ft
Action Stage
6 ft
What Floods at Each Level
15 ft
A few homes begin to flood along the stream between Route 50 and the mouth of the stream.
10 ft
Buildings on the right bank begin to flood.
9 ft
Parking lots on the right bank begin to flood.
6 ft
The banks begin to overflow into nearby floodplain, but there is no impact to life or property.
Impact statements from the National Weather Service, describing what typically happens at each water level.
7-Day Water Level Chart
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Historic Crests
| Date | Stage | Flow |
|---|---|---|
| Sep 8, 2011 | 9.21 ft | — |
| Jul 11, 2013 | 8.06 ft | 2,830 cfs |
| Jul 7, 2015 | 7.07 ft | 1,290 cfs |
About This Gauge
USGS Site
NWS LID
CTYV2
River
Flatlick Branch
County
Fairfax, VA
Coordinates
38.8822°N, 77.4319°W
Get Flood Alerts for Flatlick Branch
StormCast monitors this gauge and sends a push notification to your phone when the water level crosses into a new flood category — even at 3 AM.
Frequently Asked Questions
What is the current water level of Flatlick Branch at Chantilly?
The Flatlick Branch at Chantilly gauge is maintained by USGS (site 01656903) and reports water levels every 15 minutes. Visit this page to see the latest reading updated live, or download StormCast to get push alerts when levels rise.
What is flood stage for Flatlick Branch at Chantilly?
The NWS-defined flood stage for Flatlick Branch at Chantilly is 9 feet. Action stage begins at 6 feet. Moderate flooding starts at 10 feet, and major flooding at 15 feet.
How do I get alerts when Flatlick Branch rises?
Download StormCast free on Google Play, go to River Gauges, and add Flatlick Branch at Chantilly to your watchlist. StormCast will send a push notification to your phone whenever the water level crosses into a new NWS flood category.
Where is the Flatlick Branch at Chantilly gauge located?
The gauge is located in Fairfax County, Virginia at coordinates 38.8822°N, 77.4319°W. USGS site number: 01656903. Data is provided by the U.S. Geological Survey and the National Weather Service.
More Resources
Source & Notes
Data provided by: US Geological Survey, Observations courtesy of U.S. Geological Survey
- Stage may be affected by ice.