The Orange River (from Afrikaans/Dutch: Oranjerivier) is a river in Southern Africa.
It is the longest river in South Africa. With a total length of 2,432 km (1,511 mi), the Orange River Basin extends from Lesotho into South Africa and Namibia to the north.
It rises in the Drakensberg mountains in Lesotho, flowing westwards through South Africa to the Atlantic Ocean.
The river forms part of the international borders between South Africa and Lesotho and between South Africa and Namibia, as well as several provincial borders within South Africa. Except for Upington, it does not pass through any major cities.
The Orange River plays an important role in the South African economy by providing water for irrigation and hydroelectric power. The river was named the Orange River in honour of the Dutch ruling family, the House of Orange, by the Dutch explorer Robert Jacob Gordon.
Wildlife
The Orange River has no large animals. It lies outside the range of the Nile crocodile, and although hippopotami were once abundant, they were hunted to extermination in the 19th century.
The Orange River has a relative paucity of species diversity. A 2011 survey found only 16 species of fish present.Three of these, the common carp, the Mozambique tilapia, and the western mosquitofish are not indigenous. Another exotic species, rainbow trout, is found in the river headwaters in Lesotho.
The smallmouth yellowfish (Labeobarbus aeneus) is a popular sport fish endemic to the Orange-Vaal River system.
Seven species are endemic to the Vaal-Orange River system:
Rock-catfish (Austroglanis sclateri)
Maluti redfin or Maloti minnow (Pseudobarbus quathlambae)
Namaquab barb (Barbus hospes)
River sardine (Mesobola brevianalis)
Smallmouth yellowfish (Labeobarbus aeneus)
Largemouth yellowfish (Labeobarbus kimberlyensis)
Orange River Mudfish (Labeo capensis)
