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°13'18", long 74°46'41"
referenced to North American Datum of 1983, Trenton City, Mercer
County, NJ, Hydrologic Unit 02040105, on left bank 450 ft upstream from
Calhoun Street Bridge at Trenton, 0.5 mi upstream from Assunpink Creek,
0.9 mi north of Morrisville, PA, and at river mile 134.5.
PERIOD OF RECORD.--
Continuous-record discharge station, February
1913 to current year. October 1912 to February 1913 monthly discharge
only, published in WSP 1302. Gage-height records collected in this
vicinity since 1904 are contained in reports of the National Weather
Service. Peak discharges recorded at Lambertville, NJ, 14.3 mi upstream
of bridge on Calhoun Street for water years 1898 to 1906.
WSP 951: Drainage area. WSP 1302: 1913-20. WSP
1382: 1924, 1928.
Water-stage recorder with telemetry. Datum of gage is
NGVD of 1929. Prior to Sep 30, 1965, at datum 7.77 ft higher. Feb 24,
1913 to Oct 2, 1928, non-recording gage on downstream side of highway
bridge at site 450 ft downstream.
Records good, except for estimated discharges, which
are fair. Diurnal fluctuations at medium and low flow caused by power
plants on tributary streams. Flow regulated by Lakes Wallenpaupack and
Hopatcong (see 01455400), and by Pepacton, Cannonsville, Neversink
Reservoirs and many smaller reservoirs. Diversion from Pepacton,
Cannonsville, and Neversink Reservoirs. Diversion to Bradshaw and
Merrill Creek Reservoirs and to Delaware and Raritan Canal (see
01460440). Water diverted just above station by Borough of Morrisville,
PA and City of Trenton for municipal supply.
EXTREMES FOR PERIOD OF RECORD.--
Maximum discharge, 329,000
/s, Aug 20, 1955, maximum flow since 1692, gage height,
28.60 ft, from high-water mark in gage house, current datum, from
rating curve extended above 230,000 ft3
/s, on basis of
flood-routing study; minimum discharge, 1,180 ft3
/s, Oct 31,
EXTREMES OUTSIDE PERIOD OF RECORD.--
Flood of Oct 11, 1903
reached an elevation of about 28.5 ft above NGVD of 1929, discharge,
estimated at 295,000 ft3
/s. Maximum elevation known, 30.6 ft
above NGVD of 1929, Mar 8, 1904, from floodmark, due to ice jam.
PERIOD OF RECORD.--
Water years 1945 to current year.
Dissolved Oxygen: October 1962 to current year. Recorded once daily
Dissolved Oxygen, Percent of Saturation: October 2001 to current
pH: June 1968 to current year. Recorded as once daily during
Specific Conductance: October 1963 to current year. Recorded as once
daily during years 1964 to 1968, 1979.
Suspended Sediment Concentration: September 1949 to March 1982.
Suspended Sediment Discharge: September 1949 to March 1982.
Water Temperature: October 1944 to current year. Recorded as once daily
during years 1945 to 1953, 1962, 1964, 1979.
Turbidity: November 2000 to current year.
Data were collected in cooperation with the U.S. Geological Survey National
Water-Quality Assessment (NAWQA) Program
and the Delaware River Basin Commission
The accuracy of continuous water-quality data can be found here
EXTREMES FOR PERIOD OF DAILY RECORD.--
DISSOLVED OXYGEN, PERCENT OF SATURATION: Maximum, 199 %, Jul 5, 2010;
minimum, 59 %, Aug 9, 2005.
pH: Maximum, 10.3 standard units, Aug 9, 10, 1983; minimum, 5.3
standard units, Jun 22, 1972.
SPECIFIC CONDUCTANCE: Maximum, 468 microsiemens/cm, Jan 11, 1999;
minimum, 63 microsiemens/cm, Jul 7, 1984.
WATER TEMPERATURE: Maximum, 34.0°C, Jun 18, 1957; minimum, -0.6°C, on
many days during winter months in water years 1954-57.
TURBIDITY: Maximum, 880 FNU, Jun 28, 29, 2006; minimum, <0.5 FNU, on
many days throughout the period of record.
Inundation Maps Now Available for this Gage.
National Weather Service flood stage for this
gage is 20.0 ft.
Forecasts for this gage are issued by the National Weather Service
Forecast information is available here.