Where the Northern Cape, the Eastern Cape and the Free State meet, there lies a great body of water. In fact, the line dividing the Eastern Cape and the Free State runs right through the middle of this dam, as the mighty Orange River feeds into it. Colonel Robert J Gordon, a Dutch explorer and soldier, was the first European to see the Orange River in 1777, and he named it the Orange River in honour of the Dutch Royal Family.
A part of the Orange River Development Scheme, the Gariep Dam, formerly known as “Hendrik Verwoerd Dam”, is the largest dam in South Africa. “Gariep” is Khoekhoe word for “river”, which was also the original name of the Orange River. The hydro-electrical power station houses four 90 MW generators, which adds 360 megawatts to the grid (enough to supply 70 000 households with electricity). Some phenomenal stats exist for this dam. It has a surface area of 374 km2, and a total storage capacity of approximately 5,340,000 megalitres. The shoreline circumference is roughly 435 km. The wall is 88 m high and 914 m long, containing approximately 1.73 million m³ of concrete. There are 13 km of passages and halls within this dam wall. The dam’s primary purpose is for irrigation, domestic and industrial use, and for power generation.
“The Orange River Project (ORP) was one of the largest and most imaginative projects of its kind in South Africa” according to New World Encyclopedia. The brainchild of Dr AD Lewis (who, as Secretary of Water Affairs, launched the idea in 1928), the ORP was built to tap the unused waters of the Orange River. The Orange–Fish Tunnel is an 82.8 km long irrigation tunnel (with a diameter of 5.35 m) which was built to divert water from the Orange River to the Fish River valley. It is apparently the longest continuous enclosed aqueduct in the southern hemisphere. The inlet tower ingests water from the Gariep Dam at Oviston (an Afrikaans acronym Oranje-VISrivier TONnel). After heading South under the Suurberg mountain plateau, it releases the water to the Teebus Spruit, the Groot Brak River and also farther on to the valleys of the Great Fish River and the Sundays River. The tunnel ranges in depth below the surface between 80 metres and 380 metres on a gradient of 1:2000.
The first serious visit to the dam site (by engineers of the Department of Water Affairs and the consultants) took place during October 1963 and by April 1964 the first of the nearly 3 500 people eventually employed on the project began to arrive. The village that was built in 60s to house this labour force has developed into a holiday resort and the ideal stopover between the north and the south of our country. The construction of the dam took the Department of Water and Sanitation six years – between 1966 and 1972.
You will notice a set of “teeth” projecting over the crest of the dam wall. These are known as Roberts Splitters. They assist in dissipating the kinetic energy of the overspill water, making it tumble instead of falling in a steady scouring sheet, which could erode the rock at the foot of the wall (which is a major problem plaguing Kariba). These simple yet well-engineered splitters were named after a South African engineer, Lieutenant-Colonel DF Roberts. He came up with the design in 1936, long before this dam was built. First applied to Loskop Dam in 1937, they’ve been used on 23 dams in South Africa, including Gariep, Vaal, and Vanderkloof – and have subsequently also been deployed around the world.
The Gariep Dam Nature Reserve is the Free State’s largest nature reserve. It consists of the Gariep dam and an 11 237 ha game sanctuary on its northern shore. This reserve apparently has the largest population of springbok of any reserve in the country. Also of interest are the Rubber-Duck Nationals – The Gariep 500 which are hosted annually on the dam in February.
Overall, a very interesting spot to stop of you’re travelling and need a spot to stay over…
Jacqui Ikin & The Cross Country Team