South Africa

Contents - Previous - Next

GEOGRAPHY, POPULATION AND WATER RESOURCES

The Republic of South Africa has a total area of 1.22 million km². Only 15% of the total area - 18 million ha - is considered as cultivable. The cultivated area in 1988 was about 10.8 million ha, excluding the area cultivated in the former homelands.

TABLE 1
Basic statistics and population

The population is estimated at 40.6 million (1994), of which 49% is urban. The average population density is about 33/km², but ranges from more than 100/km² in the rural areas of the former homelands to only 21/km² in the other parts of the country. The annual demographic growth rate is estimated at 2.4%.

The agricultural sector contributes 3.9% to GDP (1991) and employs 9.8% of the economic active population. Nevertheless, agriculture is one of the largest sectors of employment because of the large numbers of peasants in the former homelands, who are not yet included in the statistics.

Climate and water resources

The average annual rainfall is 451 mm, ranging from less than 10 mm in the western deserts to 1 200 mm/year in the eastern part of the country. A vast expanse of the country is considered arid (21% of the area has less than 200 mm/year rainfall) or semi-arid (44% of the area receives between 200 and 500 mm/year). Therefore 65% of the country does not receive enough rainfall for successful dryland farming. The major part of the country has summer rainfall from November to February, while the southwestern corner has hot dry summers and rainy winters.

The drainage network of South Africa comprises two main systems, separated by the high escarpment in the eastern part of the country:

• The Orange River system, with its major tributary, the Vaal, drains almost the entire plateau, some 48.5% of the total land area. Despite its large catchment area, it contributes only 22.5% to the total runoff.
• The rivers draining the eastern slopes of the escarpment - the Tugela, Great Kel, Great Fish, Sundays and Gourits Rivers - drain only 13% of the total land area but account for approximately 43% of the total runoff.

South Africa

TABLE 2
Water balance

TABLE 3
Irrigation and drainage

The total annual surface runoff is estimated at 45.2 km³ or about 10% of annual rainfall. Of this amount, 40 km³ are generated within the country, while 5.2 km³ come from Lesotho. However, much of this volume is lost through flood spillage and evaporation, so that only about 33 km³/year is economically usable. The total dam capacity is estimated at 26.9 km³ The dams command virtually all the runoff from the plateau, while the untapped resources are concentrated along the coast.

The groundwater resources are estimated at 4.8 km³/year In 1980, about 1.79 km³ were exploited. It is foreseen that groundwater use will increase, especially in the western part of the country, which lacks perennial rivers.

According to a 1986 projection for 1990 by the Department of Water Affairs, total water withdrawal is estimated at 13.3 km³ (1990) (Figure 1), while 5.21 km³ are necessary to maintain the level of lakes and wetlands.

FIGURE 1: Water withdrawal /total: 13.3 km³ in 1990)

FIGURE 2: Irrigation techniques. full or partial control (1991)

IRRIGATION DEVELOPMENT

The potential for full or partial control irrigation development, based on soil and water availability and suitability, is estimated at 1.5 million ha.

The Total water managed area is estimated at 1.27 million ha, consisting only of full or partial control irrigation. Three irrigation techniques are used (Figure 2).

• Surface irrigation, consisting of furrow, border and basin irrigation, is applied on 396 000 ha (1991). Its costs vary from $US 100 to $US 1 400/ha, while application efficiency ranges from 55 to 65%.
• Sprinkler irrigation is applied on 660 000 ha (1991), including movable lateral pipes and central pivot systems, used to irrigate 160 000 ha. Efficiency varies from 75 to 85%, and development costs are between $US 500 and 2 000/ha.
• Micro-irrigation is applied on 144 000 ha (1991), including drip and micro-jet irrigation. Efficiency ranges from 85 to 95%, and the development costs are between $US 1 300 and 2 800/ha.

Four types of irrigation schemes can be distinguished in South Africa, according to the type of management (Figure 3):

• The Government Water Schemes, covering 329 000 ha in 1994, are operated by the Department of Water Affairs. The government provides the funds for infrastructure ($US 4 300/ha on average in 1994), with farmers contributing, through water charges, an average of 30% of the operation and maintenance (O&M) costs. The scheme size varies between 120 and 36 000 ha, divided into 8 200 farms with an average size of 40 ha;
• The Irrigation Boards (IB), covering 155 000 ha in 1994, were developed on the basis of legislation which enables groups of private individuals to obtain statutory powers. Prior to 1984, the Department of Water Affairs administered the IBs. From 1984 to 1994 the Department of Agriculture was responsible for supervision, and in January 1995 control reverted to the Department of Water Affairs and Forestry. The Government provides one-third of the infrastructure cost ($US 3 950/ha on average in 1994); the O&M costs are entirely covered by the water tariffs. Scheme sizes vary between 60 ha and 20 000 ha;
• The private schemes, covering 660 000 ha in 1992, are irrigated by private farmers on holdings of a size varying between 10 and 2 000 ha. The Department of Agricultural Development provides investment subsidies, up to a maximum of $US 2 140/ha per owner. The average cost for irrigation development was about $US 1 885/ha in 1993. In these schemes, no water charge is applied;
• Schemes of the Rural Development Programme, located in the former homelands, cover 70 000 ha. The infrastructure development funds are provided by the government, and can be as high as $US 6 500/ha. In the developing areas, irrigated community gardens are gaining popularity. A conservative estimate is that South Africa has about 5 000 such gardens of between 1 and 10 ha, benefiting 750 000 people.

The main irrigated crops are pasture, wheat (with a yield of up to 6 t/ha), lucerne (11 t/ha), maize (up to 9 t/ha) and irrigated sugar cane (where yields ranging from 160 t/ha up to 210 t/ha have been obtained) (Figure 4).

FIGURE 3: Irrigation management

Subsidized subsurface drainage covers 54 000 ha. About 110 000 ha of irrigated land in South Africa is affected by waterlogging or salinization.

INSTITUTIONAL ENVIRONMENT

The Water Act of 1956 makes a legal distinction between private surface water - which belongs to the riparian land owner - and public surface water, the use of which is subject to various restrictions. Under the Water Act, Government Water Control Areas (GWCA) can be established to safeguard public water resources against overexploitation. Drought, increased demand and claims from neighbouring countries are factors contributing to the establishment of GWCAs. Another section of the Water Act prohibits the construction of private reservoirs larger than 250 000 m³ or diversion of discharge exceeding 110 l/s.

Two ministries are involved in water management and irrigation development:

• the Ministry of Water Affairs and Forestry, through the Department of Water Affairs, monitors the surface- and groundwater resources, formulates the national water strategy, and operates the Government Water Schemes; and
• the Ministry of Agriculture, through the Department of Agricultural Development, Directorate of Irrigation Engineering, promotes irrigation engineering, performs technology transfer to farmers, and allocates subsidies to private farmers, if the design complies with the norms and standards of the Department. It also provides support to IB schemes that are essentially privately initiated, executed and run. State intervention is limited to ensuring that IB schemes that are to be financed by means of State-guaranteed loans are economically viable and financially sound.

The Water Research Commission (WRC) is a public institution which promotes, coordinates and funds water research.

TRENDS IN WATER RESOURCES MANAGEMENT

Irrigation development in the former homelands is constrained by communal land ownership, which results in lack of tenure security and limited access to land for the farmers.

Water demand projections indicated an annual growth of 1.5% between 1990 and 2010, ranging from 3.5 % for urban and industrial use to 1% for irrigation. The moderate predicted growth for irrigation is caused by low economic returns on irrigation water and, since 1984, the sharp increase in costs of irrigation equipment (20% per year) compared with a modest increase in agricultural produce prices.

FIGURE 4: Major irrigated crops (1988)

An increase in irrigation efficiency is necessary to overcome the reduction in water availability. Abolishment of the subsidised water charges would lead to an improved irrigation efficiency and a reduction of the area under low-value crops. Present government policy is to transfer as many Government Water Schemes as possible to IBs, with O&M costs fully paid by the farmers.

The reduction in water availability will probably result in an increase in conflicts over water allocation. For instance afforestation vs sugar cane in Natal; power generation vs irrigation in Eastern Transvaal; or conflicts between farmers in the developing sector and farmers in the commercial sector about the water quantity to be allocated.

MAIN SOURCES OF INFORMATION

Department of Agricultural Development. 1991. Spotlight on irrigation development in the RSA: the past, present and future.

Department of Water Affairs. 1986. Management of the water resources of the Republic of South Africa.

Directorate of Agricultural Trends. 1988. Agricultural statistics.

FAO. 1992. South Africa, Agricultural sector mission, Irrigation reconnaissance.

Water Research Commission. 1991. Researching and applying measures to conserve natural irrigation resources.

Water Research Commission. 1994. Irrigation development in southern Africa with special reference to South Africa.

Contents - Previous - Next