ABSTRACT
Throughout history, water has always been considered to be an essential requirement for human survival. Not surprisingly, the early civilizations developed near major perennial rivers such as the Nile, the Tigris-Euphrates and the Indus. However, during the earlier times, the clusters of the human population were small, the ranges of the human activities were very limited and generally water was plentiful and of reasonably good quality. However, as the human population steadily increased over the centuries, and the range of the human activities expanded, especially after the Industrial Revolution, water resources, both in terms of quantity and quality, started to come under increasing stress in many parts of the world than ever before in history.
