Gariep_Dam=The Gariep Dam forms the largest storage reservoir in South Africa with a total storage of approximately 5 500 Mm³ and a surface area of more than 370 km² when full. The dam is the central structure of the original Orange River Project which involves the supply of water to parts of the Vaal, Fish and Sundays catchments as well as to irrigation along the Orange River itself.
Water from the Gariep Dam is released downstream into the Orange River through four generators which are each capable of producing 90 MW of electricity at a flow rate of approximately 200 m³/s. The hydro-power plant can therefore provide up to 360 MW of electricity at a flow rate of 800 m³/s.
The Gariep Dam is 88 m high (90,5 m above foundation level), with a crest length of 914 m and contains approximately 1,73 Mm³ of concrete. It is situated in a gorge at the entrance to Ruigte Valley, 5 km east of Norvalspont. It is a combined gravity and arch dam built entirely of concrete.
Image: McKenzie