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USGS 01400000 North Branch Raritan River near Raritan NJ


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LOCATION.--Lat 40°34'14", long 74°40'45" referenced to North American Datum of 1983, Branchburg Township, Somerset County, NJ, Hydrologic Unit 02030105, on right bank, 400 ft upstream from U.S. Route 202, 1.4 mi upstream from confluence with South Branch Raritan River, and 2.7 mi west of Raritan.
DRAINAGE AREA.--190 mi2.
PERIOD OF RECORD.--June 1923 to current year. Monthly discharge only for June 1923, published in WSP 1302. Prior to October 1943, published as "at Milltown".
REVISED RECORDS.--WSP 1552: 1924-26, 1928-35. WDR NJ-79-1: 1971-78(P). WDR US-2011: 1997(P), 2004-10(P).
GAGE.--Water-stage recorder with telemetry. Concrete control since Sep 1, 1936. Datum of gage is 50.43 ft above NGVD of 1929. Prior to Oct 17, 1936, non-recording gage at site 30 ft downstream at same datum.
REMARKS.--Records good, except for estimated discharges, which are fair. Stage-discharge relationship affected by variable-stage backwater from the confluence with the South Branch Raritan River. From Dec 10, 2010 to present, water-stage recorder at North Branch Raritan River at South Branch (station 01400010), located just above the confluence with South Branch Raritan River, used as auxiliary gage when stage is above 3.40 ft to adjust for variable backwater. Some releases from Round Valley Reservoir enter stream upstream from gage. Occasional regulation due to gate operation at Ravine Lake, 13.8 mi upstream.
EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 29,000 ft3/s, Sep 16, 1999, gage height, 18.98 ft; minimum discharge, 3.0 ft3/s, Nov 28, 1930, as a result of probable temporary regulation.


PERIOD OF RECORD.--Water years 1923-25, 1960-76, 1978-80, 1997 to current year.
DISSOLVED OXYGEN, PERCENT OF SATURATION: September 2009. pH: September 2009. SPECIFIC CONDUCTANCE: September 2009. WATER TEMPERATURE: September 2009.
REMARKS.--Discrete water-quality data were collected as part of the New Jersey Ambient Surface-Water-Quality Monitoring Network.

Peak Flood Chart

Gage Photo

National Weather Service flood stage for this gage is 10.0 ft.

Forecasts for this gage are issued by the National Weather Service routinely year-round.
Forecast information is available here.

This station managed by the New Jersey Water Science Center.

Available Parameters Available Period
1981-10-01  2022-09-26
2007-10-01  2022-09-26


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Summary of all available data for this site
Instantaneous-data availability statement

Discharge, cubic feet per second

Most recent instantaneous value: 218 09-26-2022   15:15 EDT
Graph of  Discharge, cubic feet per second

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Daily discharge, cubic feet per second -- statistics for Sep 26 based on 94 water years of record more
Median Mean 75th
Most Recent
Value Sep 26
7.50 52 85 145 155 218 1700

Gage height, feet

Most recent instantaneous value: 2.99 09-26-2022   15:15 EDT
Graph of  Gage height, feet

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