TheOrange River (fromAfrikaans/Dutch:Oranjerivier) is a river inSouthern Africa. It is the longest river inSouth Africa. With a total length of 2,432 km (1,511 mi), the Orange River Basin extends fromLesotho into South Africa andNamibia to the north. It rises in theDrakensberg mountains in Lesotho, flowing westwards through South Africa to theAtlantic Ocean. The river forms part of the international borders between South Africa and Lesotho and between South Africa and Namibia, as well as several provincial borders within South Africa. Except forUpington, it does not pass through any major cities. The Orange River plays an important role in the South African economy by providing water for irrigation andhydroelectric power. The river was named the Orange River in honour of the Dutch ruling family, theHouse of Orange, by the Dutch explorerRobert Jacob Gordon. Other names include simply the word for river, inKhoekhoegowab orthography written as!Garib, which is rendered in Afrikaans asGariep River with the intrusion of avelar fricative in place of thealveolar click,[4]Groote River (derived fromKai !Garib) orSenqu River (used in Lesotho), derived fromǂNū "Black".[5] It is known inisiZulu asisAngqu.[6]
The course and watershed of the Orange River, Caledon River and Vaal River (ǀHaiǃarib). This map shows a conservative border for the watershed. Specifically, theKalahari basin is excluded, as some sources say it isendorheic.[7] Some other sources using computational methods show a basin which includes parts ofBotswana (and hence of the Kalahari).[8]
The Orange rises in the Drakensberg mountains along the border between South Africa and Lesotho, about 193 km (120 mi) west of the Indian Ocean and at an altitude of over 3,000 m (9,800 ft). The extremity of the Orange River inside Lesotho is known as theSenqu. Parts of the Senqu River freeze in winter because of the high altitude. This creates droughts downstream, which mainly affect goat and cattle production.
Orange River south ofRosh PinahSenqu River Near Ha Potomane (Cutting Camp) in Quthing, LesothoOrange River near Hopetown
The Orange River then runs westward through South Africa, forming the south-western boundary of theFree State province. In this section, the river flows first into theGariep Dam and later into theVanderkloof Dam. From the border of Lesotho to below the Vanderkloof Dam, the river bed is deeply incised. Further downstream, the land is flatter, and the river is used extensively for irrigation.
At the western point of the Free State, southwest ofKimberley, the Orange meets with its main tributary, theVaal River, which forms much of the northern border of the province. From here, the river flows further westward through the arid wilderness of the southernKalahari region andNamaqualand in theNorthern Cape province to meet with Namibia at 20°E longitude. From here, it flows westward for 550 km (340 mi),[9] forming the international border between the province and Namibia'sǁKaras Region. On the border, the river passes the town ofVioolsdrif, the mainborder post between South Africa and Namibia.
This image shows the last 100 km (62 mi) or so of the Orange River, in which the gravel deposits in the river bed and along the banks are rich with diamonds, and several diamond mines operate along this stretch.
In the last 800 km (500 mi) of its course, the Orange receives many intermittent streams (such as theFish River), and several largewadis lead into it. In this section, theNamib Desert terminates on the north bank of the river, so under normal circumstances, the volume of water added by these tributaries is negligible. Here, the bed of the river is once again deeply incised. TheAugrabies Falls are located on this section of the Orange, where the river descends 122 m (400 ft) in a course of 26 km (16 mi).
The Orange empties into the Atlantic Ocean between the small towns ofOranjemund (meaning "Orangemouth") in Namibia andAlexander Bay in South Africa, about equidistant betweenWalvis Bay andCape Town. Some 33 km (21 mi) from its mouth, it is obstructed byrapids andsand bars and is generally notnavigable for long stretches.
The river has a total length of 2,432 km (1,511 mi).
In thedry season, the volume of the water in the river is considerably reduced because of the rapid run-off andevaporation. At thesource of the Orange, the rainfall is about 2,000 mm (79 in) per annum, but precipitation decreases as the river flows westward; at its mouth, the rainfall is less than 50 mm (2.0 in) per year. The factors that support evaporation, though, tend to increase in a westerly direction. In thewet season (summer), the Orange river becomes a brown coloured torrent. The huge mass ofsediment carried constitutes a long-term threat to engineering projects on the river.[10]
The total catchment of the Orange River (including the Vaal) extends over 973,000 km2 (376,000 sq mi), i.e. equivalent to about 77% of the land area of South Africa (1,221,037 km2 (471,445 sq mi)). Around 366,000 km2 (141,000 sq mi) (38%), however, are situated outside the country in Lesotho, Botswana, and Namibia.
Some of the earliest precolonial inhabitants called the riverǂNūǃarib, referring to its black colour, or sometimes justKai !Arib ("Great River"), from which is derived the Afrikaans versionGariep,[11] and translation "Groote Rivier".[9] The early Dutch name for the river was just that translation, Groote Rivier, meaning "Great River".[12] The river was named the Orange River byColonel Robert Gordon, commander of theUnited East India Company (VOC) garrison at Cape Town, on a trip to the interior in 1779.[9] Gordon named the river in honor ofWilliam V ofOrange.[9] A popular but incorrect belief is that the river was named after the supposedly orange color of its water, as opposed to the color of its tributary, theVaal River, which name is derived from the nameǀHaiǃarib "pale river" (vaal beingAfrikaans for pale or grey). Since the end ofapartheid, the name "Gariep" has had greater favour in official correspondence in South Africa, although the name "Orange" has greater international recognition.[9] In Lesotho, where the river rises, it is known as the Senqu River, derived from the originalKhoemana name.
Panorama taken from afluorspar-rich hill overlooking a bend in the River, which was in flood due to above-normal rains
The Eastern Cape Geographical Names Committee has advertised its intention to consider a name change from the colonial name, for that portion of the river that forms the border between theEastern Cape and the Free State, with suggestions beingIGqili orSenqu.[13][14] The advertisement placed in theAliwal Weekblad newspaper states that the "present name is perceived to have a strong association with the history of colonial subjugation and has therefore no place under the current democratic dispensation."[14]
In South African folklore, the Orange River is often associated with theGrootslang, a mythical being resembling a giant serpent, which is often connected to the river's alluvial diamonds. The Grootslang is described as living in a gem-filled cave connected to the Orange River by a natural pipe through which the diamonds gradually enter the river.[15] Other sites said to be lairs of the creature include the pool beneath the King George Cataract atAughrabies Falls, which is also said to be a source of diamonds,[15] and a large rock in the middle of the river itself. In this version of the legend, the Grootslang is also said to prey on cattle from the river's banks.[16]
TheGeneral Hertzog Bridge over the Orange River atAliwal North on the southwestern border with the Free State: Note the remains of theFrere Bridge on the left.
As the collection point for the majority of South Africa's water, the Orange River plays a major role in supporting agriculture, industry, and mining. To assist in this, two large water schemes have been created, the Orange River Project and theLesotho Highlands Water Project. Historically, the river played an important role in the South Africandiamond rush, with the first diamonds in the country being discovered inalluvial deposits on the Orange. Today, several commercial diamond mines operate along the final stretch of the Orange River and around its mouth.
Because of the lack of dangerous animals and high water levels during summer, the river is used for recreationalcanoeing andrafting. Orange River rafting has become very popular with many companies using their camps along the river from which to operate. The most popular trips are four-day and six-day river trips that take place either along the gorge below theAugrabies Falls or along theRichtersveld area.
The Orange River Project (ORP) was one of the largest and most imaginative projects of its kind in South Africa. It was constructed byHendrik Verwoerd's government at the height of the apartheid era. The ORP was built to exploit the waters of the Orange River—which, without the Vaal River, represents some 14.1% of the total runoff in South Africa—and in the process, to satisfy an increasing demand for water. The main objectives of the project were:
TheGariep Dam nearColesberg is the main storage structure within the Orange River. From here, the water is supplied in two directions, westward along the Orange River (via hydroelectric power generators) to theVanderkloof Dam and southward through theOrange-Fish Tunnel to the Eastern Cape.
TheGariep Dam on the Orange River is the largest dam in South Africa, and was a key part of the Orange River Project.
Eskom operates hydroelectric power stations at both the Gariep Dam and the Vanderkloof Dam. The hydroelectric power station at the Vanderkloof Dam was the first power-generation station in South Africa situated entirely underground. The townsOviston andOranjekrag were established to facilitate the construction and operation of the new infrastructure.
View over the eastern part of the dam, with the water intake at Oviston
Avineyard on the Orange RiverVarious irrigation projects along the river
Irrigation in the vast area downstream of the Vanderkloof Dam, which has turned thousands of hectares of aridveld into highly productive agricultural land, was made possible by the construction of the Gariep and Vanderkloof Dams. Old established irrigation schemes such as those atBuchuberg,Upington,Kakamas, andVioolsdrif have also benefitted because regulation of the flow is now possible. On the Namibian side of the river,Aussenkehr produces grapes with the help of water from the Orange.
In recent years, thewine-producing areas along the Orange River have grown in importance. Irrigation in the Eastern Cape has also received a tremendous boost, not only from the additional water being made available, but also owing to improvement in water quality. Without this improvement, the citrus farmers along the Lower Sundays River would almost certainly have continued to suffer losses of productivity.
TheLesotho Highlands Water Project was conceived to supplement the water supply in the Vaal River System. Water is delivered to South Africa by means of the delivery tunnel which passes under the Lesotho South Africa border at theCaledon River, and then under the Little Caledon River south of Clarens in the Free State, and discharges into the Ash River about 30 kilometres (19 mi) further to the north. The scheme became viable when water demands inGauteng reached levels that could no longer be supported economically by alternative schemes such as the Tugela River-Vaal Riverpumped storage scheme, which used theSterkfontein Dam, located nearHarrismith in the Free State.
In 1867, the first diamond discovered in South Africa, theEureka Diamond, was found nearHopetown on the Orange River. Two years later, a much larger diamond known as theStar of South Africa was found in the same area, causing a diamond rush. This was soon eclipsed by the diamond rush to mine diamonds directly fromkimberlite atKimberley in 1871, although alluvial diamonds continued to be found in the Orange. Today, several commercial diamond mines operate on the last stretch of the river, as well as the beaches around its mouth. Diamond mines also operate on the middle stretch of the river.
Rafting on the Orange River is a popular tourist activity.
During the temperate months of March and April, given good rains and thesluices of the dams being open, a canoeist (or rafter) can easily travel 30 kilometres (19 mi) per day. The lower reaches of the river are most popular, because of the spectacular topography. Commercial tours are available, and these expeditions depart from the border town ofVioolsdrif.
The Orange River has no large animals. It lies outside the range of theNile crocodile, and althoughhippopotami were once abundant, they were hunted to extermination in the 19th century.[17] The Orange River has a relative paucity of species diversity. Surveys from 1995 to 2001 in the Lower Orange River found 19 different fish species from eight different families. The two non-native species recorded in the surveys wereCyprinus carpio andOreochromis mossambicus, the latter of which had increased rapidly in abundance since the early 1980s.[18] Another exotic species,rainbow trout, is found in the river headwaters in Lesotho.
The smallmouth yellowfish (Labeobarbus aeneus) is a popularsport fish endemic to the Orange-Vaal River system.
Seven species areendemic to the Vaal-Orange River system:[19]
^the surrounding area was once known as "Transgariep" ("the land across the Gariep") but the name has long been obsolete. See Karel Schoeman,Early White Travellers in the Transgariep, 1819-1840, Protea Boekhuis, 2012 (ISBN9781869190163)
^Næsje, T. F.; Hay, C. J.; Nickanor, N.; Koekemoer, J.; Strand, R.; Thorstad, E. B. (2007).Fish populations, gill net catches and gill net selectivity in the Lower Orange River, Namibia, from 1995 to 2001. Trondheim: NINR. pp. 5–6.ISBN978-82-426-1791-0.
