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°39'58", long 74°24'14"
referenced to North American Datum of 1983, Watchung Borough, Somerset
County, NJ, Hydrologic Unit 02030105, on right bank at Seeley Mills,
250 ft downstream from Blue Brook, 300 ft downstream from bridge on New
Providence (Diamond Hill) Road, and 0.5 mi northwest of Scotch
PERIOD OF RECORD.--
Annual maximum gage, water years 1927-38 (in
files of Union County Park Commission), 1958-68 (in files of Union
County Park Commission), 1969-79. Fragmentary records 1944-53 (in the
files of the U.S. Geological Survey). Occasional low-flow measurements,
water years 1959-64, 1969. Continuous-record discharge station, June
1979 to current year.
WDR NJ-81-1:1979(M). WDR NJ-87-1:1971(M),
Water-stage recorder with telemetry. Datum of gage is
184.44 ft above NGVD of 1929. From 1944 to 1953, water-stage recorder
and masonry dam about 400 ft downstream, above lower Seeley Mills dam
at different datum. From July 1969 to May 1979, crest-stage gage about
450 ft downstream below lower Seeley Mills dam (washed out May 29,
1968) at different datum.
Records fair, except for estimated discharges and
discharges below 1 ft3
/s, which are poor.
EXTREMES FOR PERIOD OF RECORD.--
Maximum discharge, 6,240
/s, Aug 2, 1973, gage height 16.10 ft, site and datum
then in use; minimum discharge, 0.00 ft3
/s, Sep 11,
EXTREMES OUTSIDE PERIOD OF RECORD.--
Flood of July 23, 1938
reached an elevation of 196.5 ft (New Jersey Geological Survey datum;
above lower Seeley Mills dam), discharge, 5,840 ft3
(computed by State Water Policy Commission).
National Weather Service flood stage for
this gage is 5.5 ft.