The Vaal River ( ; Khoemana: ) is the largest tributary of the Orange River in

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...

. The river has its source near Breyten in

Mpumalanga Mpumalanga () is one of the nine provinces of South Africa. The name means "East", or literally "The Place Where the Sun Rises" in the Nguni languages. Mpumalanga lies in eastern South Africa, bordering Eswatini and Mozambique. It shares bor ...

province, east of

Johannesburg Johannesburg ( , , ; Zulu language, Zulu and Xhosa language, Xhosa: eGoli ) (colloquially known as Jozi, Joburg, Jo'burg or "The City of Gold") is the most populous city in South Africa. With 5,538,596 people in the City of Johannesburg alon ...

and about north of Ermelo and only about from the

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or approximately 20% of the water area of Earth#Surface, Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia (continent), ...

. It then flows westwards to its

confluence In geography, a confluence (also ''conflux'') occurs where two or more watercourses join to form a single channel (geography), channel. A confluence can occur in several configurations: at the point where a tributary joins a larger river (main ...

with the Orange River southwest of Kimberley in the

Northern Cape The Northern Cape ( ; ; ) is the largest and most sparsely populated Provinces of South Africa, province of South Africa. It was created in 1994 when the Cape Province was split up. Its capital is Kimberley, South Africa, Kimberley. It includes ...

. It is long, and forms the border between Mpumalanga,

Gauteng Gauteng ( , ; Sotho-Tswana languages, Sotho-Tswana for 'place of gold'; or ) is one of the nine provinces of South Africa. Situated on the Highveld, Gauteng is the smallest province by land area in South Africa. Although Gauteng accounts f ...

and North West Province on its north bank, and the Free State on its south. It is the third largest river in

after the Orange River (2200 km long) and the

Limpopo River The Limpopo River () rises in South Africa and flows generally eastward through Mozambique to the Indian Ocean. The term Limpopo is derived from Rivombo (Livombo/Lebombo), a group of Tsonga settlers led by Hosi Rivombo who settled in the mou ...

(1750 km long) and was established as the main source of water for the great Witswatersrand area after the 19th century gold rush.9 longest rivers. SA9. Accessed 2 April 2018.
/ref> The Vaal Dam lies on the Vaal River in Deneysville just south of the border between

and the Free State. The Vaal River is the longest river wholly within the borders of South Africa. ''Vaal'' is a Dutch name (later

Afrikaans Afrikaans is a West Germanic languages, West Germanic language spoken in South Africa, Namibia and to a lesser extent Botswana, Zambia, Zimbabwe and also Argentina where there is a group in Sarmiento, Chubut, Sarmiento that speaks the Pat ...

), translated by the Griquas or Boers from an earlier Kora Khoekhoe or !Orakobab name, sometimes spelled as ''Tky-Gariep'' (in Khoekhoegowab orthography it is ''ǀHai!garib'', drab river). Both Vaal and ''Tky'' (in modern orthography ǀHai) mean "drab" or "dull", which alludes to the colour of the waters, especially noticeable during flood season when the river is laden with silt. In the upper reaches the river was named ''iLigwa'' ( Sindebele), ''Ikwa or Igwa'' ( isiZulu), ''ilikwa'' ( siSwati), ''lekwa'' (

Sesotho Sotho (), also known as ''Sesotho'' (), Southern Sotho, or ''Sesotho sa Borwa'' is a Southern Bantu languages, Southern Bantu language spoken in Lesotho as its national language and South Africa where it is an official language. Like all Ba ...

), or ''cuoa'' by the Khoikhoi, all referring to the plain it traverses.

History

Historically, the river formed the northern border of

Moshoeshoe I Moshoeshoe I () ( – 11 March 1870) was the first king of Lesotho. He was the first son of Mokhachane, a minor Tribal chief, chief of the Bamokoteli lineage, a branch of the Koena tribe, Koena (crocodile) clan. In his youth, he helped his fat ...

's Basotho kingdom at its height in the mid-19th century, then became the boundary between two Boer republics: The

South African Republic The South African Republic (, abbreviated ZAR; ), also known as the Transvaal Republic, was an independent Boer republics, Boer republic in Southern Africa which existed from 1852 to 1902, when it was annexed into the British Empire as a result ...

(later the Transvaal province) and the

Orange Free State The Orange Free State ( ; ) was an independent Boer-ruled sovereign republic under British suzerainty in Southern Africa during the second half of the 19th century, which ceased to exist after it was defeated and surrendered to the British Em ...

. The geographic name "Transvaal" comes from the name of this river, meaning "beyond the Vaal river". This was in respect to the

Cape Colony The Cape Colony (), also known as the Cape of Good Hope, was a British Empire, British colony in present-day South Africa named after the Cape of Good Hope. It existed from 1795 to 1802, and again from 1806 to 1910, when it united with three ...

and Natal, which were the main areas of European settlement at the time, and which lay south of the Vaal. During the late 19th century, there was an influx of people migrating to the

Witwatersrand The Witwatersrand (, ; ; locally the Rand or, less commonly, the Reef) is a , north-facing scarp in South Africa. It consists of a hard, erosion-resistant quartzite metamorphic rock, over which several north-flowing rivers form waterfalls, w ...

in search of

gold Gold is a chemical element; it has chemical symbol Au (from Latin ) and atomic number 79. In its pure form, it is a brightness, bright, slightly orange-yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal ...

. The Vaal River would eventually become the main water source for the Witwatersrand. The growing population initially used water from the groundwater of the Zuurbekom Wells in

's West Rand. Eventually these would dry up and people would need a new source that could provide for their domestic, agricultural and industrial activities. Water schemes were initially established by the private sector to deal with the growing demand. These included the Braamfontein Water Company's Vierfontein Syndicate of 1893 and the Sivewright Concession of 1887 by the Johannesburg Waterworks and Exploration Company. Water was expensive and largely inaccessible for most inhabitants.

Rand Water Board

The Rand Water Board was established in 1903 to take over the operations of the private sector with a mandate to investigate sustainable water supply and

sanitation Sanitation refers to public health conditions related to clean drinking water and treatment and disposal of human excreta and sewage. Preventing human contact with feces is part of sanitation, as is hand washing with soap. Sanitation systems ...

services. The organisation would become fully operational in 1905, supplying water in bulk to the

. The organisation's members included officials from the Johannesburg Town Council, The Chamber of Mines and other local authorities within the Witwatersrand. Rand Water responded to

water scarcity Water scarcity (closely related to water stress or water crisis) is the lack of fresh water resources to meet the standard water demand. There are two types of water scarcity. One is ''physical.'' The other is ''economic water scarcity''. Physic ...

by imposing restrictions on Witwatersrand inhabitants in 1913. It also developed major water schemes that would respond to the growing demand. Between 1914 and 1998, the organisation partnered with various government and private entities to drive the Vaal River scheme and the barrage (1914–1924). The Vaal River scheme was an initiative established to manage water distribution. The Rand Water board also established the Vereeniging Pumping Station (1924), the Zwartkopjes Pumping Station, the Vaal Dam (1938), the Zuikerbosch Pumping Station (1949) and the Lesotho Highlands Water Project (1998).

River Basin

Rain and underground water collects in pans,

vlei A vlei (; ) is a shallow minor lake, mostly of a seasonal or intermittent lake, intermittent nature. It even might refer to seasonal ponds or marshy patches where frogs and similar marsh dwellers breed. Commonly, vleis vary in their extent, or e ...

s and streams and where these connect, the westward flowing Vaal River is born. The river flows west into the Grootdraai Dam near Standerton,

. On its course to the Vaal Dam in Vereeniging, the river is joined by a number of tributaries. The Little Vaal River starts in an escarpment near Ermelo. Near Memel in the Free State is where the Klip River begins. The Watervals River begins in Secunda,

. The Wilge River used to meet the Vaal River before the Vaal Dam was built in 1938; now the water flows straight into the dam. Kromelmboogspruit joins the Vaal near the Vaal Barrage. Vaal River near Venterskroon

Vaal Dam

Since the Vaal River's

surface runoff Surface runoff (also known as overland flow or terrestrial runoff) is the unconfined flow of water over the ground surface, in contrast to ''channel runoff'' (or ''stream flow''). It occurs when excess rainwater, stormwater, meltwater, or other ...

is erratic, large dams have been built along its course to collect the water. In the past, before the river was established as the official source of water for part of the

, several small dams were built by farmers for

irrigation Irrigation (also referred to as watering of plants) is the practice of applying controlled amounts of water to land to help grow crops, landscape plants, and lawns. Irrigation has been a key aspect of agriculture for over 5,000 years and has bee ...

. When the construction of the Vaal Dam was completed in 1938, the dam ensured the supply of water throughout each year even when the river was not full. The dam would receive water from different

catchment area A catchment area in human geography, is the area from which a location, such as a city, service or institution, attracts a population that uses its services and economic opportunities. Catchment areas may be defined based on from where people are ...

s through various projects.

Tugela-Vaal Transfer Scheme

Two water transfer schemes were developed to supply the economic heartland of the country (then recognised as the Pretoria-Witwatersrand-Vereeniging complex) by channelling water into the Vaal River from other

s between the 1970s and 1990s. These include the Lesotho Highlands Water Project and

KwaZulu-Natal KwaZulu-Natal (, also referred to as KZN) is a Provinces of South Africa, province of South Africa that was created in 1994 when the government merged the Zulu people, Zulu bantustan of KwaZulu ("Place of the Zulu" in Zulu language, Zulu) and ...

's Tugela-Vaal Water Transfer Scheme.Rivers of South Africa. Manzi's News. Accessed 31 March 2018.
/ref> The Tugela-Vaal Transfer Scheme was completed in 1974 to transfer from the

Tugela River The Tugela River (; ) is the largest river in KwaZulu-Natal Province, South Africa. With a total length of , and a drop of 1370 metres in the lower 480 km, it is one of the most important rivers of the country. The river originates in M ...

in KwaZulu Natal via canals, pipelines and dams into the Vaal River system

Lesotho Highlands Water Project

The Lesotho Highlands Water Project was finally launched in 1997 and would entail a three-phase construction that would augment water from

Lesotho Lesotho, formally the Kingdom of Lesotho and formerly known as Basutoland, is a landlocked country in Southern Africa. Entirely surrounded by South Africa, it is the largest of only three sovereign enclave and exclave, enclaves in the world, t ...

into the Vaal River, including four major dams. From 1954, the Natural Resources Development Council proposed that

receive some water from neighbouring

. Negotiations between the two countries started in the late 1970s. A treaty for the development of the scheme was signed on 24 October 1987 by representatives of Lesotho, South Africa, the

European Union The European Union (EU) is a supranational union, supranational political union, political and economic union of Member state of the European Union, member states that are Geography of the European Union, located primarily in Europe. The u ...

United Nations The United Nations (UN) is the Earth, global intergovernmental organization established by the signing of the Charter of the United Nations, UN Charter on 26 June 1945 with the stated purpose of maintaining international peace and internationa ...

and the

World Bank The World Bank is an international financial institution that provides loans and Grant (money), grants to the governments of Least developed countries, low- and Developing country, middle-income countries for the purposes of economic development ...

. It was then estimated to cost R9.1 billion for the first phase of the project alone. South Africa pays R150 million to Lesotho each year whether they use all of the water that is supplied or not.

Basin ecology

According to Hogan the headwaters portion of the basin supports high

endemism Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

in reptiles, and lower in the watershed are elevated levels of endemism for small mammals.

Industry and agriculture

Water is drawn from the Vaal to meet the industrial needs of the

Greater Johannesburg Metropolitan Area The City of Johannesburg Metropolitan Municipality () is a Metropolitan municipality (South Africa), metropolitan municipality that manages the local governance of Johannesburg, the largest city in South Africa. It is divided into several branche ...

and a large part of the Free State. In 1881 the Kimberley Waterworks Company, provided water from the Vaal to the Cape Diamond Fields at a cost of one

shilling The shilling is a historical coin, and the name of a unit of modern currency, currencies formerly used in the United Kingdom, Australia, New Zealand, other British Commonwealth countries and Ireland, where they were generally equivalent to 1 ...

per . As a part of the Vaal-Hartz Scheme it is a major source of water for irrigation. Water drawn from the Vaal supports 12 million consumers in Gauteng and surrounding areas.

Current uses

The majority of the Vaal River water upstream of the Vaal Dam is used for

mining Mining is the Resource extraction, extraction of valuable geological materials and minerals from the surface of the Earth. Mining is required to obtain most materials that cannot be grown through agriculture, agricultural processes, or feasib ...

and industrial use such as coal mines and Sasol's energy and chemical-related activities, as well as urban use and power generation. Further downstream of the dam, water is mostly dedicated to urban requirements and, although proportionally less, a considerable amount of this section is also used for mining and industries,

and power generation.Upper Vaal WMA: Overview of water resources availability and utilisation. Department of Water Affairs. Accessed 2 April 2018.
/ref> The river regularly experiences pollution of its upper reaches, and this affects users downstream. During 2019 the Lekwa Local Municipality's main water treatment plant in Standerton was in disrepair and was causing chronic pollution problems. To assist users downstream, clean water had to be pumped into the river to dilute its high salt levels, thereby wasting a large quantity of this scarce resource. In 2021, a report released by the South African Human Rights Commission found the river to be polluted beyond acceptable levels, including the flow of raw sewerage into the River.

Tourism

The Vaal River is made up of 50 km of navigable water. The river basin thus offers a range of leisurely water activities that attract local and international tourists throughout the year. Activities include

boating Boating is the leisurely activity of travelling by boat, or the recreational use of a boat whether powerboats, sailboats, or man-powered vessels (such as rowing and paddle boats), focused on the travel itself, as well as sports activities, suc ...

yachting Yachting is recreational boating activities using medium/large-sized boats or small ships collectively called yachts. Yachting is distinguished from other forms of boating mainly by the priority focus on comfort and luxury, the dependence on ma ...

and water skiing. Deneysville is a town on the Free State side of the Vaal River and is a popular water-centre where visitors can enjoy

swimming Swimming is the self-propulsion of a person through water, such as saltwater or freshwater environments, usually for recreation, sport, exercise, or survival. Swimmers achieve locomotion by coordinating limb and body movements to achieve hydrody ...

, kiteboarding,

catamaran A catamaran () (informally, a "cat") is a watercraft with two parallel hull (watercraft), hulls of equal size. The wide distance between a catamaran's hulls imparts stability through resistance to rolling and overturning; no ballast is requi ...

cruising, jet skiing,

windsurfing Windsurfing is a wind-propelled water sport that is a combination of sailing and surfing. It is also referred to as "sailboarding" and "boardsailing", and emerged in the late 1960s from the Californian aerospace and surf culture. Windsurfing gain ...

, snorkelling and

fishing Fishing is the activity of trying to catch fish. Fish are often caught as wildlife from the natural environment (Freshwater ecosystem, freshwater or Marine ecosystem, marine), but may also be caught from Fish stocking, stocked Body of water, ...