Overview of chapter
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South Africa's available freshwater resources are already almost fully-utilised and under stress. At the projected population growth and economic development rates, it is unlikely that the projected demand on water resources in South Africa will be sustainable. Water will increasingly becoming the limiting resource in South Africa, and supply will become a major restriction to the future socio-economic development of the country, in terms of both the amount of water available and the quality of what is available. At present many water resources are polluted by industrial effluents, domestic and commercial sewage, acid mine drainage, agricultural runoff and litter.
To augment supplies, South Africa is looking towards water sources in other southern African countries (e.g. Lesotho) to assist in providing sufficient water for projected future demands. However, the risks of international dependency on such a priority resource are high. Other possible sources of water, such as desalinisation of seawater and water from icebergs, may be potential options in the long-term, although currently they are too expensive to exploit. It is imperative that South Africa develop both a water-efficient economy together with a social ethic of water conservation and ultimately a culture of sustainability of water resource use.
Authors: Walmsley Dr R D, Walmsley J J, Mzuri Consultants, Silberbauer M, Department of Water Affairs and Forestry
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Background information .gif)
South Africa is a semi-arid country. Freshwater is our most limiting natural resource. South Africa receives only around half the average rainfall of other countries, and this is spread disproportionately across the country from east to west. Water availability now and in the future is heavily dependent on climate, water use and management and land-use practices.
For more background information about freshwater systems and resources, read
this section.
There are three main driving forces affecting South Africa's freshwater environment. Firstly, the natural conditions, particularly climate (see Climate and Atmospheric Change section), which is characterised by low rainfall and high evaporation rates. Together these create low available run-off. Second is the rapid population growth (see Social Dimensions section), and need for economic development and meeting of basic needs. These socio-economic activities drive water use and lead to greater water demand and increased pollution of available resources. The third driving force is the policy pertaining to national management of water resources, which determines the approach taken by relevant authorities at all levels of government to managing our freshwater resources (see Policy). Indirectly, policy pertaining to land-use practices throughout the country impact on water quality and availability.
For more information about the drivers of freshwater systems, read this section.
Population growth (see Social Dimensions section), increased economic activity (see Economic Dimensions section) and intensification of land use practices (see Terrestrial Ecosystem section) all lead to increased water demand, and increasing degradation of the resource. Already the freshwater resources of the country are under stress (Davies et al. 1993).
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| Water demand |
For instance, most of the country's major rivers have been dammed to provide water for the increasing population; in most areas wetlands have been converted for other land-use purposes, with more than 50% of the country's wetlands already lost; industrial and domestic effluents are polluting the ground- and surface waters, and changes in habitat have affected the biotic diversity of freshwater ecosystems. Despite this extensive degradation of our freshwater resources, an estimated overall increase in demand of some 52% over the next 30 years is predicted.
For more information about the above pressures read this section.
What is the status of our freshwater systems and resources?
South Africa is an arid country with only 8.6% of the rainfall available as surface water. This is one of the lowest conversion ratios in the world. The mean annual runoff (MAR) for South Africa is estimated at some 50 million m3 a-1. This is not distributed evenly throughout the country, with the Eastern seaboard having some 80% of the country's runoff, whilst the western regions tend to have low runoff. Nor is it consistent over time, with great variability between years. Similar to surface waters, South Africa's groundwater resources are relatively limited compared to world averages.
The scarcity of freshwater resources and highly variable hydrological conditions have led to every major river in South Africa being regulated in order to ensure adequate water supply for development. However, because of the spatial variability of water resources and the scarcity of water throughout the country, in many catchments the need for water exceeds the supply. This situation is likely to worsen as the discrepancies between water requirements and availability in other water-scarce catchments increase.
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| Mine drainage activities |
The scarcity of water is compounded by pollution of the surface- and ground-water resources. Typical pollutants of South Africa's freshwater environment include industrial effluents, domestic and commercial sewage, acid mine drainage, agricultural runoff, and litter. As many of these sources are spreadout across the country, it is difficult to estimate the magnitude of the pollution problem. However, Western Cape, Eastern Cape, KwaZulu-Natal and the Vaal rivers have major problems with Total Dissolved Solids (TDS), and most of South Africa's rivers have an eutrophication problems.
For more information about the state of freshwater systems in South Africa, please read this section.
The indigenous aquatic fauna and flora of South Africa are well-adapted to the variable climatic conditions, and many are reproductively opportunistic as a result.
The high levels of natural variability ensure that high biological diversity and habitat integrity are maintained. However, whilst most freshwater systems in South Africa are not negatively affected in the long-term by natural fluctuations, they must also endure increasing negative human-induced stresses, to which they are not adapted.
Ecological changes to freshwater ecosystems occur because of catchment degradation (see Terrestrial Ecosystems section); regulation of flow by impoundments; pollution; over-extraction of water; and the breakdown of natural biogeographical barriers, typically through interbasin transfers. The primary results of these are extensive habitat loss, a decrease in biodiversity and an increase in invasive and pest species. In extreme cases, these can result in ecological collapse of the functioning of the natural systems.
Additionally, riverine habitats have been so changed, that little remains of natural freshwater systems in South Africa. Many perennial rivers have become seasonal (e.g. Limpopo, Levuvhu, Letaba); floodplains that rely on regular flooding which has been attenuated have become less productive (e.g. Pongola) and many estuaries no longer have natural opening of the estuary mouth (e.g. Mfolozi).
Read this section for more information about the impacts on our freshwater systems.
There are various responses at different levels in order to manage our water resources in a sustainable manner, including developing and adhering to international initiatives, setting relevant policy through legislation, implementing policy at an operational level (institutional arrangements; enforcement and monitoring) and implementation of special programmes to combat specific problems (see Policy).
South Africa is a signatory to or abides by several international protocols that are important to water management. Most legislation pertaining to the environment affects water resources, either directly or indirectly. The most important are the Water Services Act (Act 108 of 1997) and the National Water Act (Act 36 of 1998), which fall under the authority of the Minister of Water Affairs and Forestry.
In the light of the uneven distribution of the water resources of the country and previous inequitable policies, the Water Services Act is important in ensuring that people's basic needs are met, i.e. water supply and sanitation. It ensures that there is sound planning and that water service providers are set up country-wide to cater for everyone.
The National Water Act has replaced the old Water Act (Act 54 of 1956) of 40 years standing. It has completely reformed the water law in South Africa, bringing into legislation aspects of policy that are at the forefront of sustainable resource use thinking internationally. The Act is based on the principles of sustainability of use and equity of distribution.
For more information about the response to managing freshwater resources click here.
The outcomes of these responses are largely unknown at present. Most of them have only recently been introduced and there has not been enough time to test their appropriateness and effectiveness.
For a list of possible and predicted outcomes, click here.
All human activities impact on freshwater resources in some form.
For Linkages to other sectors, click here.
Sustainable development and use of natural resources is dependent on adequate accurate, current information. In general, South Africa has extensive high quality information on water resources.
Click here for an analysis of data issues.
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There is also information about Freshwater Systems and Resources in the following reports:
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Metropolitan reports:
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Affairs and Tourism. All Rights Reserved.
Site maintained by the Directorate Environmental Information and Reporting
Last update: October 1999
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