Water demand and supply

You will recall from Study Session 1 that many countries in the world, are suffering from water stress or water scarcity. The world is heading towards a fresh water crisis, partly due to mismanagement and partly due to the unequal distribution and small amount of fresh water available in the first place. This crisis is already evident in many parts of the world, varying in scale and intensity depending on the time of the year, climate and location.

The imbalance between the demand for and the supply of water is increasing globally. On the one hand, the volume available for supply remains much the same but has additional problems of contamination of surface and groundwater sources, inefficient utilisation of available supplies and the uncertainties of climate change. On the other hand, the demand for fresh water per capita is rising as countries develop economically. Industrial development leads to additional demands for water and, at the same time, agriculture is becoming increasingly dependent on irrigation to produce food for the growing population.

The global challenge is to find ways to manage the increasing demand for water but this is not to say that everyone should use less water. Developing countries still use far less water per capita than developed regions. Household use in developing countries is especially low, reflecting the difficulty many people have in obtaining clean water for personal use. Improving access to water is important so that people can use more water for household and personal hygiene, which will improve living standards and bring significant benefits to health and well-being.

Population growth, urbanisation and migration all affect the availability and quality of water resources. With the rapid increase in urbanisation, meeting the demand for fresh water will be difficult for cities. Rapid urban growth in developing countries puts tremendous pressure on inadequate water supply systems and can lead to water shortages. The next two study sessions look more closely at urbanisation and its causes and effects.