Roper River

The Roper River is a large perennial river located in the Katherine region of the Northern Territory of Australia.

Formed by the confluence of the Waterhouse River and Roper Creek, the Roper River rises east of Mataranka in the Elsey National Park and flows generally east for over 1,000 kilometres (620 mi) to meet the sea in Limmen Bight on the Gulf of Carpentaria. The river is joined by fifteen tributaries including the Chambers, Strangways, Jalboi, Hodgson and the Wilton Rivers. The river descends 126 metres (413 ft) over its 1,010-kilometre (630 mi) course[1] and has a catchment area of 81,794 square kilometres (31,581 sq mi), which is one of the largest river catchment areas in the Northern Territory.[2] The Roper River is navigable for about 145 kilometres (90 mi), until the tidal limit at Roper Bar, and forms the southern boundary of the region known as Arnhem Land. Mataranka Hot Springs and the township of Mataranka lie close to the river at its western end. Port Roper lies near its mouth on Limmen Bight.

The river has a mean annual outflow of 5,000 gigalitres (1.1×1012 imp gal; 1.3×1012 US gal).[3]