Runs: 2200 kilometres | Province: Free State, Northern Cape
And now, His Majesty the Orange River! Call it what you will – Gariep, Groote, Senqu – this is the longest and grandest of all South African rivers. The river was named in honour of William V of Orange by Colonel Robert Jacob Gordon, commander of the Dutch East India Company garrison in Cape Town, on a trip to the interior in 1779. No river in the country meanders for longer distance than the 2 200 kilometres of the Orange. However, approximately 38% of the river is situated in the neighbouring countries. It rises in the Drakensberg in Lesotho, flowing westwards through South Africa to the Atlantic Ocean. The Orange traverses the veld region of South Africa, after which it defines the southern limit of the Kalahari and bisects the southern Namib before draining into the Atlantic at Alexander Bay. Along its course the river forms the eastern boundary of the Free State province, as well as the boundary between Namibia and South Africa. The Gariep Dam, near Colesberg, is the main storage structure within the Orange River. From here the water is supplied in two directions, namely westward along the Orange River (via hydro-electric power generators) to the Vanderkloof Dam, and southward through the Orange-Fish Tunnel to the Eastern Cape.
At the mouth of the river are rich alluvial diamond beds.