South Africa has a strong water industry and the availability in South Africa varies greatly in space and time. While the west is dry with rainfall only during the summer and as low as 100mm, the east and southeast receive rainfall throughout the year with an average of up to 1 000 mm. The area under irrigation is 1 334 562 ha.
The importance of water is as follows:
Water is the key to food security:
- without water, crops simply cannot grow.
- Water is not just for primary production
- it plays a vital role at all stages along the agricultural value chain
- Water for agriculture connects us all together
- In times of scarcity, we all have a responsibility to use water wisely, efficiently, and productively.
Located on the southern tip of Africa, the Republic of South Africa stretches between the longitudes of 17º to 33ºE and latitudes of 22º to 35ºS. Namibia bounds the country on the north-west side, while Botswana and Zimbabwe are located to the North, Mozambique and Eswatini are on the north-east. Lesotho, a landlocked country, forms an enclave within the Republic of South Africa. On the other three sides, South Africa is surrounded by oceans. The Republic has nine provinces: Limpopo, Mpumalanga, KwaZulu-Natal, Eastern Cape Province, Western Cape Province, Northern Cape Province, Northwest Province, Gauteng, and Free State. The total land area of the Republic of South Africa is 122 341 Km2. Topographically South Africa may be divided into four zones, the Plateau, the Escarpment, the folded Mountains and the Coastal Plain.
Population and land use
The current population of South Africa is 60 524 855 based on projections of the latest United Nations data. The UN estimates that on the 1 July 2022 the population will be at 60 756 135.
Land use statistics are as follows:
- Agriculture: Rainfed – 10 779 615 ha and Irrigated – 1 334 562 ha;
- Land used for pasture crops: Rainfed 1 736 614 ha and Irrigated 209 351 ha;
- Natural extensive grazing areas: 83 928 062 ha;
- Forests and woodlands: 1 179 000 ha;
- Other land use: 23 422 000 ha.
- Only 14% (17 Mha) of the total area of South Africa is suitable for rainfed crop production and a mere 3% of this area is high potential land. The area under forestry and peri-urban smallholdings accounts for some 3 Mha of the better soils.
Climate and rainfall
South Africa is classified as a water scarce country and has an estimated average annual rainfall of 495 mm. Approximately 86% of the area of the Republic of South Africa lies in the summer rainfall area. A narrow belt along the southern coast, some 4 Mha in extent, receives rain during all seasons. 13 Mha in the southern western corner have a Mediterranean climate with winter rainfall and a dry summer. The rainfall decreases from east to west, from over 1 000 mm in the east to 100 mm in the Namib and Namaqualand areas in the west. The low-lying eastern coastal belt is hot and humid in summer. Because of the altitude, summer temperatures on the high inland plateau are generally lower than could be expected. Winter temperatures in the interior often drop to below zero and frost is common.
The average rainfall of South Africa is just over half of the world average. Rainfall is seasonal and highly variable. The total internal renewable surface water resources are approximately 50 x 109 m3/a, the maximum yield is 33.3 x 109 m3/a. A storage capacity of about 32 x 109 m3/a has been created through the construction of dams. See Figure 3 for the Provincial and Country summary of dam levels as on 14 March 2022. Based on present trends in water use and population growth, South Africa is expected to reach the limits of its economically usable freshwater resources by the year 2030.
The Gariep Dam in the Free State province was completed in 1971 and is the largest dam in South Africa with a capacity of 5 342 932 000 m3 and forms part of the Orange River development scheme. With the excellent rains in die beginning of 2022 it overflows with spectacular scenes.
South Africa shares four major rivers with six neighbouring states, namely, Zimbabwe, Botswana, Mozambique, Eswatini, Lesotho and Namibia which entail international agreements on water sharing for these river basins. See Figure 5.
The surface water potential of the major drainage systems in South Africa are dominated by the Orange and the Limpopo River basins. Over 60% of the country’s river flow comes from 20% of the land area.
In comparison, the Orange River, the biggest river in South Africa, carries only 10% of the flow of the Zambezi River and about 1% of the flow in the Congo River.
Irrigation is an important factor in the production of permanent crops and in obtaining high yields from field crops. There are approximately 32 000 commercial farmers, who produce 80% of the country’s agricultural value. The distribution of irrigation capacity is that 15 000 medium and large-scale commercial farmers irrigated around 1 334 562 ha divided into the following:
Private schemes developed by owners to extract water directly from weirs, boreholes, and farm dams;
Irrigation board schemes which are privately managed by water user associations.
Government schemes which were built and operated by the Government.
Water is used to produce cereal, industry, horticulture, pasture, and forage crops. Most of these crops are also grown in smallholder farms (Agriculture). Supplementation of variable rainfall through irrigation is conspicuously more important for high value (income) crops such as potatoes, vegetables, grapes, fruit, and tobacco. Although grain and oilseed crops can be effectively grown under rainfed conditions, they will remain part of crop combinations under irrigation for production of seed and as rotational crops to maintain soil productivity.
The irrigation systems currently in general use, are differentiated as follows:
Static systems which are permanent after installation and not normally moved. This includes micro, drip, and permanent sprinkler systems. Portable systems which are moved mechanically or manually from one position to another, to irrigate the entire farmland surface. This includes quick-couple, drag-line, hop-along, big gun, side-roll, and irrigating boom systems.
Moving systems which move over the field under its own power while it irrigates. This includes centre pivot, linear, moving gun and moving irrigating boom systems.
Flood irrigation systems by which water flows under gravitation is applied to the fields. This includes basin, border, furrow, short furrow, and contour irrigation.
Following the democratic elections in 1994, a total reform of water policy and water legislation was undertaken. A completely new National Water Act was promulgated in South Africa on 1 October 1998. Key elements and principles of the new Act are:
- The South African water resources are a national asset.
- National Government i.e., the Department responsible for water resources will act as the custodian of the nation’s water resources.
- Water required to meet basic human needs and to maintain environmental sustainability will be guaranteed as a right. This will be known as The Reserve.
- The allocation of water will have the objective of achievement of equitable and sustainable economic and social development.
- The efficient use and the conservation of water will be promoted by the Act.
The National Water Resources Strategy, which outlines the objectives of water resources management for the country and provides the plans, guidelines, and strategies to achieve these goals.
The Irrigation Strategy of South Africa which identifies objectives, priorities, allocates responsibilities and ensures coordinated efforts and estimates realistic funding, as well as sets out the principles for initiatives which are being undertaken to revitalize and expand irrigation schemes in the country.
The National water act (Act 36 of 1998) of South Africa dictates that water must be protected, used, developed, conserved, managed, and controlled in a sustainable and equitable manner.