But the others are very well known. The Orange River, otherwise known as the Gariep River, Groote River or Senqu River is the longest river in South Africa. 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 Namibia and between South Africa and Lesotho, as well as several provincial borders within South Africa. Although the river does not pass through any major cities, it plays an important role in the South African economy by providing water for irrigation, as well as hydroelectric power. The river was named by Robert Jacob Gordon after the Dutch Royal House.
The Congo River (also known as the Zaire River) is a river in Africa, and is the deepest river in the world, with measured depths in excess of 230 m (750 ft). It is the second largest river in the world by volume of water discharged, though it has only one-fifth the volume of the world’s largest river, the Amazon. Additionally, its overall length of 4,700 km (2,920 mi) makes it the ninth longest river.
Its drainage basin covers 4,014,500 square kilometres (1,550,000 sq mi). The Congo’s discharge at its mouth ranges from 23,000 cubic metres per second (810,000 cu ft/s) to 75,000 cubic metres per second (2,600,000 cu ft/s), with an average of 41,000 cubic metres per second (1,400,000 cu ft/s).