During winter months, cold and ice may
result in inaccurate real-time gage height and streamflow data.
Adjustments or deletions of this data can only be done after detailed
Funding for this site is provided by:
Lat 40°38'11", long 74°27'05"
referenced to North American Datum of 1983, Watchung Borough, Somerset
County, NJ, Hydrologic Unit 02030105, on right bank at Watchung Borough
Administration Building in Watchung, 150 ft downstream from bridge on
Mountain Boulevard, 400 ft downstream from East Branch Stony Brook, and
2.9 mi upstream from confluence with Green Brook.
PERIOD OF RECORD.--
Continuous-record discharge station October
1974 to current year.
WDR NJ-86-1: 1973 (P).
Water-stage and precipitation recorder with telemetry and
crest-stage gage. Datum of gage is 162.24 ft above NGVD of 1929. Prior
to Oct 1, 1996, at datum 10.00 ft higher.
Records fair, except estimated discharges, which are
poor. Occasional regulation from Watchung and Best Lakes directly
upstream from station and other small lakes. Discharges above 500
/s from rating curve extended on basis of step-backwater
computation of peak flow. Channel significantly enlarged and modified
in 1991, and modified again in 1997 when the right wall was
EXTREMES FOR PERIOD OF RECORD.--
Maximum discharge, 5,380
/s, Sep 16, 1999, gage height, 17.16 ft, from rating
curve extended above 500 ft3
/s on basis of step-backwater
computation of peak flow; maximum gage height, 20.40 ft, Jul 14, 1975,
adjusted to current datum; minimum discharge, 0.00 ft3
Sep 13, 1982.
EXTREMES OUTSIDE PERIOD OF RECORD.--
Flood of Aug 2, 1973 reached
a stage of 24.5 ft (from floodmark; adjusted to current datum),
discharge, 10,500 ft3
/s (highest since 1896; from slope-area
measurements of peak flow).
National Weather Service flood stage for
this gage is 14 ft.
Rain gage data is available from this location at this