There's nothing else like it on Earth!

Pure water is colourless, odourless and tasteless. The blue ocean colour you see is due to reflections from the sky. Due to the chemical properties of water, pure water with nothing dissolved in it is rarely found in nature. Rivers often look brown or green due to the sand or mud in them. Water is a scarce and precious resource. Around 70 per cent of the Earth's surface is covered by water, in oceans, seas, lakes, rivers and swamps.

Unfortunately for us, most of this is salt water in the oceans and seas and much of the rest is frozen on mountains and polar ice caps. In fact, less than 1 per cent of the Earth's water is in a suitable form for human needs. Water is the most important and probably the most widely known substance on the Earth. But unless there are droughts, like we had in 1982 - 83, or floods, most of us don't think about it much.

Without water we would not live. It makes up two-thirds of our bodies. And we use it in so many ways: for drinking, for watering, for washing, for gardening, for taking away our wastes, and for all sorts of recreation. Water cools our bodies, carries nutrients through it, lubricates it and carries off wastes. In fact, water makes up 85 per cent of our blood and 75 per cent of our brain by weight. Water is all around us - in the air, the ground and every living thing. In fact, between 50 and 90 per cent of the weight of any living thing is water.