[4] 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), or cuoa by the Khoikhoi, all referring to the plain it traverses.

[6] Rain and underground water collects in pans, vleis and streams and where these connect, the westward flowing Vaal River is born.

In the past, before the river was established as the official source of water for part of the Gauteng, several small dams were built by farmers for irrigation.

A treaty for the development of the scheme was signed on 24 October 1987 by representatives of Lesotho, South Africa, the European Union, United Nations and the World Bank.

[8] Water is drawn from the Vaal to meet the industrial needs of the Greater Johannesburg Metropolitan Area 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 per 100 imperial gallons (450 L; 120 US gal).

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, irrigation and power generation.

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.

The river basin thus offers a range of leisurely water activities that attract local and international tourists throughout the year.

Deneysville is a town on the Free State side of the Vaal River and is a popular water-centre where visitors can enjoy swimming, kiteboarding, yachting, boating, catamaran cruising, jet skiing, windsurfing, snorkelling and fishing.