Water is no doubt the world's most important resource. All life depends on it: people and animals need it for drinking and it is essential for plants to grow. Water is a unique natural resource. It is also a limited one. Over the past few years the world's supply of fresh water has been under serious threat from drying up. Many people around the world do not receive enough water each day to survive and these numbers are always increasing. So why is our most precious resource disppearing infront of our eyes?