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.
The river forms at the confluence of the North and South Branches just west of Somerville (technically, at the border of Bridgewater, Branchburg and Hillsborough Townships.) It flows for approximately 16 mi (25.7 km) before slowing in tidewater at New Brunswick, and its estuary extends 14 mi (22.5 km) more entering the western end of Raritan Bay at South Amboy.
The river has served an important water transportation route since the days of the Lenape Native Americans. The name itself comes from an Algonquian word meaning "stream overflows." The name is also applied to the Raritan people, an Algonquian tribe that inhabited Staten Island, near the river's mouth. In colonial days, the river allowed the development of early industry around New Brunswick, as well as the transportation of agricultural materials from central New Jersey. During the American Revolutionary War, the river provided a means for troop conveyance. The construction of the Delaware and Raritan Canal along the right (south) bank of the river provided a critical link between New York City and Philadelphia, Pennsylvania on the Delaware River.
Comprehensive measures have been taken to reduce the pollution and increase the water quality. These actions have benefited the fish population which include (but are not limited to) largemouth bass, smallmouth bass, sunfish, catfish, trout, chain pickerel, american eels, carp and yellow perch. An occasional Pike and Musky have been taken out of the Raritan as well. The tidal portions of the river host migratory salt water species such as striped bass, fluke, winter flounder, weakfish and bluefish. Many nesting birds and water fowl make their homes in and along the length of the river. Crustaceans such as blue claw crab, fiddler crabs and green crabs are also found in the tidal sections of the river. Crayfish can be found further upstream.
The river is also used for recreational boating, including use by the rowing team of Rutgers University in New Brunswick. The river is featured in the title of Rutgers' alma mater, On the Banks of the Old Raritan. The musical 1776 mentions troops bathing in the Raritan River.
Despite its important recreational and drinking water significance, the Raritan has been ranked as the 16th most polluted river in the country, and is designated as unsafe for both fishing and swimming.
Geologists believe that approximately 6,000 years ago the lower Raritan provided the course of the mouth of the Hudson River. Following the end of the last ice age, the Narrows had not yet been formed and the Hudson flowed along the Watchung Mountains to present-day Bound Brook, then followed the course of the Raritan eastward into Lower New York Bay.
Near its mouth, the river is spanned by the Victory Bridge which carries Route 35 (connecting Perth Amboy and Sayreville, New Jersey), the Driscoll Bridge, which carries the Garden State Parkway (connecting Woodbridge Township and Sayreville), the Edison Bridge, which carries U.S. Route 9 (Connecting Woodbridge Township and Sayreville Township) and a New Jersey Transit railroad bridge.
The Raritan River is an important source of drinking water for the central portion of New Jersey. Two water purification plants, operated by New Jersey American Water, are located where the Raritan River and its largest tributary (the Millstone River) meet just east of Manville, New Jersey.
At times of drought and low water flow rates, the flow rate in the Raritan River is enhanced by planned discharges from the Round Valley Reservoir and Spruce Run Reservoir, both of which are located close to the South Branch of the Raritan River in Hunterdon County, New Jersey, and are connected to the river via outflow pipes/channels. The water levels are boosted so downstream water purification facilities will have adequate water supplies in times of drought.
The Raritan River has persistent flooding problems when excessive rain from storms affects the river basin. The flooding problems mainly affect the town of Bound Brook, which is partially built on a natural flood plain at the junction of several tributaries, and Manville, which has a large neighborhood known as Lost Valley that lies on the flood plain between the Raritan River and its largest tributary river, which is known as the Millstone River. Other towns in the Raritan River basin also experience flooding to a lesser degree.
Record flooding in the aftermath of Hurricane Floyd in September 1999 (43 ft (13.1 m) flood crest, 15 ft (4.6 m) above flood stage) caused renewed interest in a flood control project called the Green Brook Flood Control Project, which will essentially protect Bound Brook from a 150 year flood. Two levees have been built on the perimeter of Bound Brook, but the main levee necessary to keep the Raritan River from flooding the town has not been built as of early 2007 and is not scheduled to be completed for at least another five years.
(In alphabetical order)
The Raritan river is formed by the confluence of:
Its main tributaries are: