Rivers of the Vaal-Orange drainage basin

Chilling at sunrise.

The Vaal and Orange Rivers, together with their tributaries, take care of the largest drainage basin in South Africa. Both of them are controlled by complex systems of dams and have artificial water flows. The dams supply the ever-increasing demand for water in urban areas, both for domestic and industrial use.

A multitude of farms line the rivers’ banks, utilizing the water for irrigation purposes. Fortunately there are still some natural sections where mountainous areas have rendered development impractical, leaving us with unspoilt stretches of river to appreciate. Another result of these mountains is gradient, forming rapids to enjoy.

The origins of the Vaal and Orange are close to the Indian Ocean, but on the wrong side of the Drakensberg range to take a shortcut to the Indian Ocean. Instead they have to travel all the way to the other side of the country to flow into the Atlantic Ocean. Their resulting average gradient is in the region of 1m/km, which is very flat by any standards.

One of the most controversial subjects as far as development is concerned, is the Lesotho Highlands Water Scheme, which is also involved in this drainage system. Water from the Katse Dam in Lesotho is tunnelled to the As River, which flows into the Saulspoort Dam. This dam is permanently overflowing and sends water down the Liebenbergsvlei River to the Wilge River and Vaal Dam. The project provides a continuous flow of between 15 cumecs and 25 cumecs, depending on electricity generation by Lesotho. There are, however, indefinite plans in the further stages of the project to pipe the water directly to the Vaal Dam, in which case the sections on the Ash and Liebenbergsvlei Rivers will be unpaddlable again.