Besides air, water is the resource most critical to sustaining life on Earth. Human beings depend on water not only for drinking, but for generating energy, growing crops, carrying waste, washing and cleaning, and running machinery. Clean water is also essential for the many species of plants and animals living in streams, rivers, and lakes.
As the human population grows and the world becomes increasingly industrialized, demands on fresh water resources are intensifying. At the same time, this very growth threatens the water supply through human and industrial pollution. Climate change is creating drought conditions in some parts of the world. Already, wars are being fought over water. It is becoming clear that water will one day replace oil as the most precious and fought-over resource on the planet.
The importance of water cannot be overstated, yet people in industrialized nations take for granted the fact that they can turn on a faucet for fresh water on demand. But, even in this water-on-demand society, contaminants and pathogens find their way into the water supply, sickening hundreds at a time.
Keeping water supplies clean, safe, and healthy requires the attention of a diverse group of people - farmers, conservationists, public policy makers, environmental health workers, and concerned citizens.
Who is responsible for the health of the world's watersheds? Is clean water a right, or a commodity to be bought and sold to the highest bidder? In the years to come, these questions will become more and more urgent. Without sufficient clean water, impoverished countries will never achieve better health and higher standards of living for their people. Without sufficient clean water, industrialized nations will not be able to meet the demands of all the enterprises that depend on water to function. Without sufficient clean water, all other productive efforts become futile.