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°44'40", long 74°21'13"
referenced to North American Datum of 1983, Millburn Township, Essex
County, NJ, Hydrologic Unit 02030103, on left bank just upstream of
pumping station intake, 100 ft upstream of bridge on private driveway
within New Jersey-American Water Company property, 0.5 mi upstream of
mouth, 1.6 mi east of Chatham, and 2.0 mi north of Summit.
PERIOD OF RECORD.--
Published 1930-65 in Special Reports of
predecessors of the New Jersey Department of Environmental Protection.
Fragmentary records for water years 1966-2001 are unpublished but
available in the files of the New Jersey Water Science Center or online
Continuous-record discharge station, October 2001 to current
Water-stage recorder with telemetry and concrete control.
Since January 21, 2010, supplementary velocity meter, water temperature
sensor,and crest-stage gage downstream of concrete control. Datum of
gage is 159.64 ft NGVD of 1929. Prior to January 21, 2010 water-stage
recorders upstream and downstream of concrete weir.
Records fair, except for estimated discharges and
discharges below 2 ft³/s, which are poor. Diversion above weir by New
Jersey-American Water Company for municipal supply. During extreme
backwater conditions from the Passaic River, reverse flow may occur due
to pumping from the gage pool by New Jersey-American Water Company.
Prior to January 21, 2010, negative flows were reported as missing or
EXTREMES FOR PERIOD OF RECORD.--
Maximum daily discharge since
October 2001, 2,890 ft³/s, Aug 28, 2011; minimum daily discharge, -32.6
ft³/s, Apr 19, 2018.
Rain gage data is available from this location at this link.
The water temperature data for this station
are temporary and will only be displayed for 120 days. Although the
instrumentation is calibrated at least once/year, the temporary
classification means that documented routine inspections and other
quality assurance measures are not performed that would make the data
acceptable for archival, retrieval, or future use in general scientific
or interpretive studies.