Introduction

Historically and culturally, water has always been considered to be a critically important resource, because without it ecosystems cannot survive. Similarly, human evolution simply would not have been possible without water. Thus, not surprisingly, water has a special place in the human psyche. For example, all major religions such as Christianity, Hinduism, and Islam give special importance and consideration to water. People, irrespective of which country of the world they live in, are generally against large-scale transfer of water to another country, whereas international trade in all other resources, both renewable and non-renewable, has been a routine activity for centuries and has seldom attracted protracted national discussions or serious political opposition. In contrast, water transfer plans between countries, and often between states within the same country, attract considerable political controversy.

From the dawn of history, water has continued to be an economically essential resource for the development of countries. However, during the twentieth century, especially during the latter half, all the western economies became stronger and more resilient than ever before, and became less and less dependent on water and the vagaries of nature. The easy availability of clean water for drinking twenty-four hours a day, at affordable prices, became the norm rather than an exception. Agriculture and food production became surplus to the needs of the people of the western world, and the vast majority of the important hydropower plants have now been constructed. Floods and droughts, for the most part, are already controlled through extensive water development projects. Concerns are now expressed only when there are catastrophic floods or prolonged severe droughts, both of which are temporary in nature. Public, political, and media interest in water, which is extensive during catastrophic events, mostly evaporates after the floods and droughts are gone, and reappears only after several years or even decades, when the next catastrophe strikes. Accordingly there is little sustained public and political interest in the developed countries in water. The availability of clean water or the impact of water availability on society are no longer major critical issues for the developed world. This situation is unlikely to change in the twenty-first century.

In contrast, the situation is very different from the perspectives of the developing countries. Availability of clean water is still a dream in most parts of the developing world. For mega-cities, from Calcutta to Istanbul, and Mexico City to Lagos, clean drinking water is simply not available from the urban water supply systems. For health reasons, drinking water has to be either boiled or filtered, or has to be consumed from bottles. Not surprisingly, the failure of the governmental system to provide clean drinking water to the citizens of Mexico City has been very efficiently compensated for by the private sector, which has developed a sophisticated and extensive distribution system for drinking water in very large plastic bottles that compares most favourably with any distribution system available for soft drinks anywhere in the world. Clean drinking water is supplied, regularly and cost-effectively, to all the households of the city that can afford it. The empty bottles are collected for reuse, along with deliveries of new supplies.

In addition to the lack of safe drinking water in the urban areas of the developing world, the developing economies are still very much dependent on water availability because of its importance to agricultural production, industrial development, and electricity generation. With expanding population and urbanization, accelerating human activities, and increasing per capita water consumption, an adequate supply of water of the right quality and subsequent wastewater disposal in an environmentally acceptable way are likely to become even more important to the developing world during the next two to three decades.