March 1, 1990
In many arid, developing countries, water has become.-an important constraint to further socioeconomic development. As population continues to increase, availability and reliable control of more and more water of appropriate quality is becoming necessary to increase agricultural production., hydropower generation and industrial activities as well as to provide for higher domestic needs. Two or-more decades ago, levels of population were significantly lower in all developing countries than they are at present, and for the most part water available for various human activities was generally considered to be reasonably adequate. When water demands exceeded supply, new sources of water were available which could be developed economically, efficiently and technologically comparatively easily. Furthermore, the environmental consciousness of the world as a whole was significantly lower than what it is today. Accordingly, with a reasonably adequate quantity of sources of clean water available, water quality was not a major consideration. The main emphasis was primarily to ensure that an adequate quantity of water was available for various human uses. To the extent water quality was considered within the context of water resources planning, the primary interest was on sediments.