6.2 Water conservation  (Page 2/3)

Apart from the pollution of water resources, the overuse of water is also a problem. In looking at the water cycle, it is easy sometimes to think that water is a never-ending resource. In a sense this is true because water cannot be destroyed. However, the availability of water may vary from place to place. In South Africa for example, many regions are extremely dry and receive very little rainfall. The same is true for many other parts of the world, where the scarcity of water is a life and death issue. The present threat of global warming is also likely to affect water resources. Some climate models suggest that rising temperatures could increase the variability of climate and decrease rainfall in South Africa. With this in mind and remembering that South Africa is already a dry country, it is vitally important that we manage our water use carefully. In addition to this, the less water there is available, the more likely it is that water quality will also decrease. A decrease in water quality limits how water can be used and developed.

At present, the demands being placed on South Africa's water resources are large. [link] shows the water requirements that were predicted for the year 2000. The figures in the table were taken from South Africa's National Water Resource Strategy , produced by the Department of Water Affairs and Forestry in 2004. In the table, 'rural' means water for domestic use and stock watering in rural areas, while 'urban' means water for domestic, industrial and commercial use in the urban area. 'Afforestation' is included because many plantations reduce stream flow because of the large amounts of water they need to survive.

Case study : south africa's water requirements

Refer to [link] and then answer the following questions:

1. Which water management area in South Africa has the highest need for water...
   1. in the mining and industry sector?
   2. for power generation ?
   3. in the irrigation sector?
   4. Suggest reasons for each of your answers above.
2. For South Africa as a whole...
   1. Which activity uses the most water?
   2. Which activity uses the least water?
3. Complete the following table, by calculating the percentage (%) that each activity contributes to the total water requirements in South Africa for the year 2000.

   Water use activity	% of SA's total water requirements
   Irrigation
   Urban
   Rural
   Mining and bulk industry
   Power generation
   Afforestation

Now look at [link] , which shows the amount of water available in South Africa during 2000. In the table, 'usable return flow' means the amount of water that can be reused after it has been used for irrigation, urban or mining.