The Vaal River system has its beginnings in the eastern highveld plains, in the vicinity of Ermelo. Shallow hollows and low hillocks form a natural sponge where water collects in pans, vleis and streams. These streams link up and the Vaal River is born, flowing westward on a long course, without rapids or waterfalls, broadening into a large river. To the Bushmen, the river was known as Gij’Gariep (“tawny”) from its muddy colour. The European name, Vaal, also means tawny. The Sotho called it iliGwa (“erratic”) because of the unpredictable variations in its flow.