Which is the longest river of South Africa?

The Orange River is the longest river in South Africa and one of the longest in southern Africa, about 2,200 km long. Its basin covers a large part of South Africa and extends into Lesotho, Namibia and Botswana.

Course of the Orange River:

• It rises in the Drakensberg (Maloti) mountains of Lesotho, where it is called the Senqu.
• It flows west across the interior plateau of South Africa.
• Its longest tributary is the Vaal river, which joins it near Douglas in the Northern Cape.
• In its lower course, it forms part of the international border between South Africa and Namibia.
• It empties into the Atlantic Ocean at Alexander Bay (on the South African side) and Oranjemund (on the Namibian side).

Origin of the name:

It was named by the Dutch explorer Robert Jacob Gordon in 1779 in honour of the Dutch royal House of Orange, not because of the colour of its water.

Importance:

• It is the main source of water for irrigation, industries and towns in the dry interior and western regions of South Africa.
• The Orange River Project includes the Gariep Dam (the largest reservoir in South Africa) and the Vanderkloof Dam.
• The Lesotho Highlands Water Project transfers water from the Orange's headwaters in Lesotho to the Gauteng region (around Johannesburg) and generates hydroelectric power for Lesotho.
• The Augrabies Falls, a spectacular waterfall in a granite gorge, lies on the Orange in the Northern Cape.

Other rivers of South Africa:

• The Limpopo forms South Africa's northern border with Botswana and Zimbabwe and flows into the Indian Ocean through Mozambique.
• The Vaal is the Orange's largest tributary and supplies water to Gauteng.
• The Tugela flows to the Indian Ocean in KwaZulu-Natal; the Tugela Falls is among the tallest waterfalls in the world.

Why not the other options?

• ✗The Limpopo is the second largest river system of the region but shorter.
• ✗The Vaal is a tributary of the Orange.
• ✗The Tugela is much shorter.