ABSTRACT
Water pollution, the main theme of this chapter, is inextricably linked to issues of water demand and the working of natural ecosytems. Fresh water is required to supply the needs of agriculture, industry and domestic users. It is also required as a means of disposing of, and transporting, wastes from these users. If fresh waters become polluted, then their use for supply purposes becomes limited, unless treated. Moreover, urbanisation changes the way in which fresh water is stored and transported at or near the ground surface. Such changes have important implications for urban water supply, waste-water disposal and water pollution. Therefore, a full appreciation of urban water pollution requires some understanding of the related issues of water demand and urban hydrology.
