Introduction

Modern man has been quick to harness this planet's water resources in the best manner considered fit by him. Growing prosperity due to the techno-scientific-industrial revolution led to prosperity and the growth of population and the consequent growth cities and other human settlements. Their growing water needs had to be met. The West went on a canal building spree and the East, Russia and later India, soon followed suit. This only means the diversion of rivers' surface flows and sometimes their over- exploitation. The earlier success of these schemes led to India's First Prime Minister Jawaherlal Nehru declaring that Dams would be the temples of modern India, thereby giving the newly independent state, a mantra. The young and vibrant nation took to the new formula with much enthusiasm and without any questioning. The present day crisis of the shortage of clean water in areas with growing population calls for a close examination of the policies followed by us during the second half of the twentieth century.

Basically fresh water is provided to us by nature through rain. The precipitation is stored in nature in the great glaciers, in natural lakes and ponds and in the roots of tress. The last named source is usually forgotten, yet all the non-glacier fed rivers have their lean season flows maintained by the roots of tress. Rain water and molten ice from little streams, merging often to form great rivers. We have mainly utilised and over-exploited the surface flows of rivers and streams that connect the sources of water mentioned above. During periods of excessive precipitation, it is the role of the rivers and streams to drain out excess water to the great oceans, often flooding large areas in the process. Sun and wind maintain the fresh water cycle, not only through evaporation and subsequent precipitation, but also through natural purification processes involving oxidation. Perhaps it is time now for us to examine if nature itself could not resolve our dilemma concerning the shortage of clean water.