Vanderkloof Dam (previously the PK le Roux Dam) is situated 130km downstream of Gariep dam on the Orange River. It forms the second largest storage reservoir in South Africa with a capacity of over 3 200 million m³. 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 400km of the Orange River.
The Vanderkloof Dam is currently the highest dam in South Africa with a wall height of 107m and a crest length of 765m. Similar to Gariep Dam, it is a composite gravity arch dam containing 1.1 million m³ of concrete and has a central arch which transitions into a gravity flank on the left bank.