|FAO Irrigation and Drainage Paper 52 Reforming water resources policy A guide to methods, processes and practices (1995)|
|Chapter 3 - Principles|
Despite the achievements of the International Drinking Water Supply and Sanitation Decade (1981-90), over one thousand million people lack access to safe water, and 1.8 thousand million do not have proper sanitation (World Bank, 1992). The backlog is rising in absolute terms.
It has been authoritatively asserted that inadequate sanitation and clean water provision remain the most serious of all environmental problems, in terms of the scale of human suffering (World Bank, 1992). Universal adequate water supply and sanitation would benefit hundreds of millions of present sufferers from such diseases as diarrhoea, roundworm infection, schistosomiasis, trachoma and guinea worm (World Bank, 1992).
These estimates indicate the importance of public health benefits in planning water systems to provide adequate universal coverage of water supply, sanitation and safe disposal. However, there are also public health risks entailed in certain water supply schemes - e.g., the creation of malaria-breeding habitats, the spread of bilharzia in irrigation schemes, increased pollution from greater water use, etc.
In applying the public health criterion to water supply, there should be adequate recognition of the benefits to national nutritional levels from having adequate food security based on local irrigated farming.