South River (Raritan River tributary)

{{short description|River in New Jersey, US}}

{{For|the borough named after the river|South River, New Jersey}}

{{Use American English|date=February 2025}}

File:South River Aerial (33615488523).jpg

File:South River from CR 535.jpg bridge in South River and Sayreville]]

The South River is a tributary of the Raritan River in central New Jersey in the United States.{{cite web | url=https://www.nan.usace.army.mil/Media/Fact-Sheets/Fact-Sheet-Article-View/Article/487579/fact-sheet-south-river-raritan-basin-nj/ | title=FACT SHEET - South River, Raritan Basin, NJ }}{{Cite web |url=http://www.nj.gov/dep/watershedmgt/DOCS/WMAFactsheets/WMA09.pdf |title=Archived copy |access-date=2015-06-13 |archive-date=2015-06-15 |archive-url=https://web.archive.org/web/20150615032610/http://www.nj.gov/dep/watershedmgt/DOCS/WMAFactsheets/WMA09.pdf |url-status=dead }}Gertler, Edward. Garden State Canoeing, Seneca Press, 2002. {{ISBN|0-9605908-8-9}}

The South River, formed by the confluence of Matchaponix Brook and Manalapan Brook, becomes tidal downstream of the Duhernal Lake dam and joins the Raritan River approximately midway between New Brunswick and Perth Amboy.

File:South River, Old Bridge-Sayreville, NJ.jpg–Sayreville border.]]

The community of Old Bridge in East Brunswick was established in the 17th century at the head of navigation of the river.{{cite web|url={{NRHP url|id=77000882}}|title=National Register of Historic Places Inventory/Nomination: Old Bridge Historic District |publisher=National Park Service|first1=Terry |last1=Karschner |date=July 1975 }}

The South River has two mouths. It used to loop inefficiently to its confluence with the Raritan River, so a shortcut called Washington Canal was created.

The river lends its name to the borough of South River.