North Branch Raritan River at South Branch
New Jersey — Water Level & Flood Stage
Located in Somerset County, New Jersey on the North Branch Raritan River. Live water level data from USGS gauge 01400010, updated every 15 minutes.
Current Water Level
Gage Height
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Streamflow
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Last Reading
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Flood Stages
Major Flood
11 ft
Moderate Flood
9 ft
Minor Flood
8 ft
Action Stage
7 ft
Flood stages defined by the National Weather Service. Gage height data from USGS Water Resources.
What Floods at Each Level
11 ft
Flooding increases impacting roadways and structures along Milltown Road, North Branch River Road, and Old York Road toward Raritan.
9 ft
Flooding increases on Old York Road. The road remains closed.
8 ft
Flooding begins on Old York Road on the west side of the bridge. The road is closed.
7 ft
The river leaves it's banks and floods surrounding open land.
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 2, 2021 | 20.26 ft | — |
| Sep 2, 2021 | 20.26 ft | — |
| Sep 15, 1999 | 18.98 ft | — |
| Sep 15, 1999 | 18.98 ft | — |
| Feb 5, 1896 | 18 ft | — |
About This Gauge
USGS Site
NWS LID
SBRN4
River
North Branch Raritan River
County
Somerset, NJ
Coordinates
40.5567°N, 74.6875°W
Get Flood Alerts for North Branch Raritan River
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 North Branch Raritan River at South Branch?
The North Branch Raritan River at South Branch gauge is maintained by USGS (site 01400010) 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 North Branch Raritan River at South Branch?
The NWS-defined flood stage for North Branch Raritan River at South Branch is 8 feet. Action stage begins at 7 feet. Moderate flooding starts at 9 feet, and major flooding at 11 feet.
How do I get alerts when North Branch Raritan River rises?
Download StormCast free on Google Play, go to River Gauges, and add North Branch Raritan River at South Branch to your watchlist. StormCast will send a push notification to your phone whenever the water level crosses into a new NWS flood category — even when your screen is off.
Where is the North Branch Raritan River at South Branch gauge located?
The gauge is located in Somerset County, New Jersey at coordinates 40.5567°N, 74.6875°W. USGS site number: 01400010. Data is provided by the U.S. Geological Survey and the National Weather Service.
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Source & Notes
Data provided by: US Geological Survey, Observations courtesy of U.S. Geological Survey