Vanderkloof_Dam=Vanderkloof Dam is situated 130 km downstream of Gariep dam on the Orange River. It forms the second largest storage reservoir in South Africa with a capacity of over 100 Mm³. The dam forms an integral component of the Orange River Project  (together with Gariep Dam) and supplies water to the Riet River catchment as well as to the various users along the remaining 1,400 km of the Orange River.
<p>The Vanderkloof Dam is currently the highest dam in South Africa with a wall height of 107 m and a crest length of 765 m. Similar to Gariep Dam , it is a composite gravity arch dam containing 1,1 Mm³ of concrete and has a central arch which transitions into a gravity flank on the left bank.</p>
<p>Construction of the dam started in April 1971 and the dam was finally commissioned in September 1977. </p>
<p>Four gates installed in the wall can discharge up to 8 500 m³/s in total through the flood sluices which are positioned on the left flank of the dam. Water released from the Gariep Dam flows into Vanderkloof Dam where it is either transferred through the Orange/Riet Canal to the Riet River basin or released downstream through two hydro-power generators. The generators can each produce 120 MW of electricity at a discharge of approximately 200  m³/s. The hydro-power plant can therefore provide up to 240 MW of electricity at a flow rate of 400 m³/s.</p>
Image: Van Wyk