The Vaal River is the largest tributary of the Orange River in South Africa. The river has its source near Breyten in Mpumalanga province, east of Johannesburg and about 30km north of Ermelo and only about 240km from the Indian Ocean. It then flows westwards to its conjunction with the Orange River southwest of Kimberley in the Northern Cape. It is 1120km long, and forms the border between Mpumalanga, Gauteng and North West Province on its north bank, and the Free State on its south.TributariesSome of its tributaries include the Harts River, Vals River, Waterval River, Bamboes Spruit, Blesbokspruit, Mooi River, Vet River, Renoster River, Riet River, Klip River and Wilge River.
