Water Situation in South Africa
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Water is life. For millions for years life on earth has been dependant on water for survival. When Neil Armstrong landed on the moon in 1969 he described Planet Earth as “a shining blue pearl spinning in space”. The blue colour is, in fact, the amount of water that is present on the surface. 70% of the earth’s surface is covered with water but of this, approximately 97% is salt water, with the remaining 3% being fresh water. Of this 3%, less than 1% is available for life on earth, whilst the rest is in the form of ice at the poles. But where does water come from?
The water that we have on earth is very old. The water that we are using now was used by the dinosaurs millions of years ago. This is because the earth recycles its water, i.e. it reuses its water. This recycling of water is called the water cycle. Water exists on earth as water droplets and is found in oceans, rivers, lakes, dams, swimming pools, the soil, etc. Heat from the sun causes some of these water droplets to change from a liquid to a gas, called water vapour. This is called evaporation. The water vapour then rises into the atmosphere. As the water vapour rises it cools down and changes from a gas to a liquid, and thus back into water droplets. This is called condensation. When these water droplets are in the atmosphere they join together and form clouds.
When these droplets get too heavy to stay in the atmosphere they fall to the earth as rain, hail, snow, etc. This is called precipitation. Some of these water droplets fall into oceans, some into rivers and streams, some into lakes and dams, and some onto the land where it either seeps into the ground or runs off the surface into rivers, lakes, dams or the ocean. Water knows no boundaries and as it flows over the earth’s surface it is used by communities of plants, animals and humans in order to survive. These water droplets can then be reheated by the sun and the whole cycle repeats itself.
The amount of water on earth is constant and cannot be increased or decreased, but it is unevenly distributed across the earth. South Africa receives an annual rainfall of 492 millimetres whereas the rest of the earth receives 985 millimetres. This is nearly half the earth’s average. Thus South Africa is classified as a water-stressed country.
Distribution of Mean Annual Rainfall in South Africa
There is also uneven distribution of rainfall across South Africa. The eastern half of the country is much wetter than the western half due to the nature of the weather conditions. South Africa also experiences alternating periods of droughts and floods which affects the amount of water across South Africa. In addition, hot dry conditions result in a high evaporation rate. Scientists predict that with global warming, South Africa will experience much wetter wet seasons and much drier dry seasons, resulting in an increase in floods and droughts.
Presently there are a large number of dams all over South Africa that store this precious water. There are also a number of water transfer schemes that move water from one catchment via pumps, pipes and canals into another catchment. Gauteng is supplied with water from the Vaal Dam catchment, which includes the Vaal River, Wilge River and all their tributaries. There are two water transfer schemes that feed into the Vaal Dam catchment, namely the Lesotho Highlands Water Project, which obtains water from the mountains of Lesotho, and the Thukela-Vaal Water Transfer Scheme, which obtains water from Kwa-Zulu Natal and is released into the Vaal Dam catchment when needed. According to the Department of Water and Environmental Affairs, the demand for water will outstrip supply in Gauteng by 2013, and in the whole of South Africa by 2025. South Africa cannot afford to build more dams and water transfer schemes as they cost large amounts of money. Thus water in South Africa is in great demand, and as the human population increases with its increasing needs for survival, the greater is the demand for water.
Water Use in South Africa
|Agricultural Use (including irrigation)||60%|
|Urban & Domestic Use||11.5%|
|Mining & Industrial Use||10.5%|
(Source: Nature Divided Land Degradation in South Africa, Ashwell, A & Hoffman, T, 2001)
Water Use in Households
|Low-Income Household||Mid to High-Income Household|
|Baths & Showers||19%||32%|
|Other eg. cooking, washing dishes and clothes, drinking, etc.||8%||14%|
Households with Gardens
(Source: Water – How is it used at home, HE Jacobs, LC Geustyn and BF Loubser, 2005)
A further problem adding to this demand is water quality. Water quality is defined as water which is safe, drinkable and appealing to all life on earth. In South Africa the scarce fresh water is decreasing in quality because of an increase in pollution and the destruction of river catchments, caused by urbanisation, deforestation, damming of rivers, destruction of wetlands, industry, mining, agriculture, energy use and accidental water pollution. As the human population increases, there is an increase in pollution and catchment destruction.
See alsoCauses of Water Pollution
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