Raritan River

Last Updated: May 10, 2026

Total streamflow across the Raritan River was last observed at 552 cfs, and is expected to yield approximately 1,095 acre-ft of water today; about 23% of normal. River levels are low and may signify a drought. Average streamflow for this time of year is 2,417 cfs, with recent peaks last observed on 2021-09-02 when daily discharge volume was observed at 108,800 cfs.

Maximum discharge along the river is currently at the Raritan River Below Calco Dam At Bound Brook Nj reporting a streamflow rate of 283 cfs. This is also the highest stage along the Raritan River, with a gauge stage of 17 ft at this location. This river is monitored from 2 different streamgauging stations along the Raritan River, the highest being situated at an altitude of 43 ft, the Raritan River At Manville Nj.

The Raritan River is a 90-mile long river in central New Jersey that flows through several counties, including Somerset and Middlesex.


15-Day Long Term Forecast


River Details

Last Updated 2026-05-09
Discharge Volume 1,095 ACRE-FT
Streamflow 552.0 cfs
Past 24 Hours: -173.0 cfs (-23.86%)
Percent of Normal 22.84%
Maximum 108,800.0 cfs
2021-09-02
Seasonal Avg 2,417 cfs
       
River Streamflow Levels
Streamgauge Streamflow Gauge Stage 24hr Change (%) % Normal Minimum (cfs) Maximum (cfs) Air Temp Elevation
Raritan River At Manville Nj
USGS 01400500
269 cfs 4.18 ft -19.7
Raritan River Below Calco Dam At Bound Brook Nj
USGS 01403060
283 cfs 17 ft -27.44
Seasonal Discharge Comparison
Maximum Streamflow Discharge
Streamflow Elevation Profile

The Raritan River is a major river of central New Jersey in the United States. Its watershed drains much of the mountainous area of the central part of the state, emptying into the Raritan Bay on the Atlantic Ocean.