The Challenge More often than not people settle in areas where there is not a good source of water nearby. This is the case with the Witwatersrand area. At the end of the 19th century, many people came to the Witwatersrand in search of gold. As the mining town of Johannesburg grew, there wasn’t enough water in the area to meet everyone’s needs. Attempts by the Johannesburg Water Works Company to meet the demand were hampered by the Great Drought of 1895. Frequent complaints concerning water led to the appointment of the Water Works Commission in 1895 to examine ways in which Johannesburg could be provided with good quality drinking water. A geologist by the name of Dr Draper, was commissioned by the commission to assist. After some search on the farm Zuurbekom, Dr Draper found what everybody was looking for. He tied his handkerchief to the branch of a thorn bush and arriving back in Johannesburg, told the Water Works Commission “go to Zuurbekom, you will find my handkerchief tied to a tree, sink a borehole there and you will find water, plenty of it.” In 1896 and 1897 the Water Works Commission secured a stable supply of water from the Zuurbekom Water Supply Companies wells. In 1903 the Water Works Commission established Rand Water in order to ensure that the Witwatersrand received enough clean, safe drinking water. Groundwater Initially Rand Water used groundwater from the Zuurbekom Wells on the West Rand. This water was of such good quality that it didn’t require any cleaning (purification). Natural Drainage When the water from the Zuurbekom Wells could no longer supply enough water for the growing population of the Witwatersrand, the Vaal River to the south of Johannesburg was chosen as a new water source. In 1923 Rand Water dammed the Vaal River to form the Vaal River Barrage Reservoir. In 1938 the Vaal Dam was built upstream of the Vaal River Barrage Reservoir, which is now the main source of water for Rand Water. Rivers such as the Vaal, Klip and Wilge Rivers naturally flow into the Vaal Dam. These rivers flow through agricultural land and rural settlements with very little industry. This means that the water in the Vaal Dam is of a good quality by international standards. The Vaal River System 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. As the Vaal River flows westward it flows into the Grootdraai Dam. This dam has a total storage capacity of 350 million cubic meters, a surface area of 39 square kilometers and an average depth of 27 meters. On its course to the Vaal Dam a number of rivers join the Vaal River:
- the Little Vaal that begins in the escarpment near Ermelo;
- the Klip River that begins near Memel in the Free State;
- the Watervals River that begins in Secunda;
- the Wilge River, that used to meet the Vaal River before the Vaal Dam was built but now flows straight into the Vaal Dam.