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USGS 01398500 North Branch Raritan River near Far Hills NJ


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LOCATION.--Lat 40°42'30", long 74°38'10" referenced to North American Datum of 1983, Far Hills Borough, Somerset County, NJ, Hydrologic Unit 02030105, on left bank 75 ft upstream from Ravine Lake Dam, 1.3 mi southeast of Peapack, 1.6 mi north of Far Hills, and 2.3 mi upstream from Peapack Brook.
DRAINAGE AREA.--26.2 mi2.
PERIOD OF RECORD.--October 1921 to September 1975, October 1977 to current year. Operated as crest-stage gage, water years 1976-77. Monthly discharge only for some periods, published in WSP 1302.
REVISED RECORDS.--WSP 781: Drainage area. WSP 1552: 1922-23, 1924-25(M), 1935(M). WSP 1902: 1954.
GAGE.--Water-stage recorder with telemetry and crest-stage gage above masonry dam. Datum of gage is 224.49 ft above NGVD of 1929 (New Jersey Geological Survey benchmark). Prior to June 18, 1925, non-recording gage in stilling box at left end of dam at same datum.
REMARKS.--Records fair, except for estimated discharges, which are poor. Records formerly included diversion by small turbine at dam (average discharge, 3.0 ft3/s) which returned to river 1,000 ft downstream from Ravine Lake Dam. Turbine is no longer operated. Flow regulated occasionally by operation of waste gate in dam. Discharges above 4,000 ft3/s from rating curve extension on basis of flow-over-dam computation of peak flow.
EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 6,390 ft3/s, from rating curve extended above 4,000 ft3/s on basis of flow-over-dam computation of peak flow. Aug 28, 1971, gage height, 7.28 ft; minimum discharge, 0.0 ft3/s, occurred many days while lake was filling.

Peak Flood Chart

Gage Photo

National Weather Service flood stage for this gage is 6 ft.

Rain gage data is available from this location at this link.

This station managed by the New Jersey Water Science Center.

Available Parameters Available Period
1981-10-02  2021-09-25
2007-10-01  2021-09-25


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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: 40.8 09-25-2021   11:45 EDT
Graph of  Discharge, cubic feet per second

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Daily discharge, cubic feet per second -- statistics for Sep 25 based on 97 water years of record more
Median 75th
Mean Most Recent
Value Sep 25
3.00 8.4 14 24 29 40.8 380

Gage height, feet

Most recent instantaneous value: 2.28 09-25-2021   11:45 EDT
Graph of  Gage height, feet

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