Leading article: A precious resource draining away

Due to two exceptionally dry winters, a hosepipe ban is in prospect in the south-east of England. Meanwhile, parts of Kenya and Somalia are in the grip of a severe drought. From the Home Counties to the Horn of Africa, human societies are confronted with one of the great looming issues of the new century: access to fresh water.

Of course, access to water in Britain is not a question of life and death. But in much of the world it is a quite different story. One in five people on our planet lacks access to clean water. Diseases from unclean water are responsible for filling half of the world's hospital beds. Perhaps the most shocking statistic, on this World Water Day, is that 6,000 children die every day due to poor water and sanitation.

The problem will grow more acute. In nations such as China and India, millions are crowding into vast cities for work, exerting ever more pressure on water resources. And as new factories are built in these countries, an increasing amount of water is sucked up for industrial purposes. Water is scarcer in the countryside too. The United Nations Global International Waters Assessment revealed yesterday that the overuse of water for farming is the biggest environmental threat to the world's freshwater supplies. Irrigation for agriculture will continue to drain aquifers as farmers seek to meet the rising demands for food from a growing human population. Global warming is adding to the effect. The desert regions of the world will spread and our planet will become more arid.

The results for human societies threaten to be ugly. We are already seeing conflicts breaking out between herdsmen and farmers in Africa over water. The volatile Middle East is likely to be next. The number of "water scarce" countries in that region is growing. According to one German academic: "The fight for water will be more dramatic than the fight for oil in the long run."

The development agency Tearfund has called for a doubling of international aid for water and sanitation projects. This is certainly affordable. It is less than a third of what the rich world spends annually on bottled water. Yet we must recognise that the world cannot increase its supply of fresh water. All we can do is change how we use it. The global failure to conserve water is an echo of our failure to conserve energy. In developing countries we must encourage the adoption of more efficient farming techniques. And in the rich world we must have more water metering to conserve supplies and penalise waste. We are now beginning to recognise how dependent we are on precarious water supplies. Unless we act swiftly to preserve them, we will live to witness the terrible consequences of that dependence.