NOTICE: This continuous water-quality monitor (water temperature, chlorophyll, and phycocyanin) will be discontinued on September 1, 2021, due to completion of the data collection portion of the Downstream Fate and Transport of Cyanobacteria and Cyanotoxins in the Raritan River Basin, New Jersey study.

SURFACE-WATER RECORDS
LOCATION.--Lat 40°40'40", long 74°52'45" referenced to North American Datum of 1983, Clinton Township, Hunterdon County, NJ, Hydrologic Unit 02030105, on left bank, 0.7 mi upstream of dam at Lake Solitude, 1.0 mi northeast of High Bridge, and 4.4 mi upstream from Spruce Run.
DRAINAGE AREA.--65.3 mi².
PERIOD OF RECORD.--Continuous-record discharge station October 1918 to current year. Monthly discharge only for some periods, published in WSP 1302.
REVISED RECORDS.--WSP 601: 1924. WSP 781: Drainage area. WSP 1552: 1919(M), 1920(M), 1921, 1923, 1924(M), 1927-28(M), 1934(M), 1941(M).
GAGE.--Water-stage recorder with telemetry and crest-stage gage. Concrete control since Sep 28, 1930. Datum of gage is 282.10 ft above NGVD of 1929 (levels from New Jersey Geological Survey benchmark). Prior to Sep 30, 1921, reference point at same site and datum.
REMARKS.--Records fair, except for estimated discharges, which are poor. Discharges above 2,400 ft³/s from rating curve extension on basis of contracted opening calculation. Occasional regulation at low flow from unknown source.
EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 6,910 ft³/s, Jan 25, 1979, gage height, 12.07 ft, from rating curve extended above 2,400 ft³/s on basis of contracted opening computation; maximum gage height, 14.26 ft, Jan 28, 1994, as a result of an ice jam; minimum discharge, 6.6 ft³/s, Oct 11, 1930.
EXTREMES OUTSIDE PERIOD OF RECORD.--Floods of Feb 6, 1896, Mar 2, 1902, and Oct 9, 1903 reached discharges at High Bridge of 7,560 ft³/s, 3,840 ft³/s, and 2,670 ft³/s, respectively (according to reports of the New Jersey State Geologist).

Peak Flood Chart

National Weather Service flood stage for this gage is 10 ft.