Figure 2e.8: Water use by sector in Southern Africa, 1900-2025
Source: Shiklomanov 1999
Some urban water distribution networks in southern Africa are poorly maintained and highly inefficient. In South Africa, for example, the supplier Rand Water estimates that up to 70 per cent of water is lost every year from the Soweto supply, due to leakages, costing US$100 800 per day (UNCHS/UNEP 2001). Similarly, irrigation is said to be less than 50 per cent efficient, with the majority of farms being irrigated by wasteful flooding and overhead sprinkler systems, while only 10 per cent use the more efficient microjet and drip irrigation systems (Chenje 2000). Mozambique has larger water resources than other countries in the sub-region, yet access to potable and irrigation water is more limited than in the drier countries, mainly due to infrastructure damage from the long civil war (IUCN 2000).
The response to this situation over the past 30 years has been to dam or to modify nearly all the water courses in the sub-region, in order to meet demand. Southern Africa has the highest concentration of dams and interbasin transfer schemes anywhere in Africa (World Commission on Dams 2001). The Kariba Dam, for example, located on the Zambezi River, and shared between Zambia and Zimbabwe, has a capacity of 180 km3. With a surface area of some 5 500 km2, it is one of the largest dams in the world. It was constructed primarily to provide hydropower to the two countries, and has a generation capacity of 1 320 MW (Soils Incorporated (Pty) Ltd and Chalo Environmental and Sustainable Development Consultants 2000).
Significant strides have been made towards the development of infrastructure for water supply and sanitation services. Access to safe drinking water improved from an average figure of 52.6 per cent in 1990 (WRI, UNEP and UNDP 1990) to 58 per cent in 1998 (WRI, UNEP, UNDP and World Bank 1998). Such access, however, varies between rural and urban areas, with the latter enjoying better access. There are also disparities between countries, with the greatest access to water in Botswana (95 per cent) and the least access in Angola (38 per cent) (WHO/UNICEF 2000). Water policies need revising to redress this issue, combining demand management (using economic incentives to control usage) with meeting basic needs (through improved equity in access and supply). South Africa has enacted such legislation, in the form of the National Water Act, Act 36 of 1998. In Windhoek, Namibia, water tariffs were increased in 1996 by 30 per cent, and household water consumption exceeding 60 m3/month was penalized with even higher rates, with the effect of reducing average water consumption by 25 per cent (Eales, Forster and Du Mhango 1996).
In addition, countries of southern Africa have made considerable efforts to cooperate in the management of shared water resources (see Box 2e.9). At the national level, countries have also made a shift towards IWRM and true cost pricing, in order to control demand. Instruments invoked to effect this include the removal of subsidies, and cost recovery from consumers. In Namibia, for example, subsidies-including those on water-accounted for 1 per cent of GDP in 1993 (IUCN 2000), but have gradually been lifted, while, in Zimbabwe, most large-scale and smallholder farmers used not to pay for irrigation water at all. The reuse of wastewater is being increasingly considered as a step towards IWRM in the region. The city of Windhoek already treats and reuses water to supply 19 per cent of the 42 510 m3 that the city uses every day (IUCN 2000).
|Box 2e.9 Mechanisms for international cooperation over shared water resources in Southern Africa|
|Source: SADC 2000|