How much rain do we get?
Almost three quarters of the rain that falls lands in the sea. The Melbourne CBD and a wide sweep of the northern and western part of the city and its outskirts are in a low rainfall area with less than 700 mm a year. Most of our water comes from catchments in the Yarra Ranges, on the edge of Melbourne, which get more rain than the lower plains.
Pure water has no taste or odour. If you could see very deep pure water you would see a bluish tinge.
Made up of one Oxygen and two Hydrogen atoms, water is sometimes called the universal solvent because of its ability to dissolve many substances.
It's the only substance that you will find naturally in the three different states of matter:
- solid as ice, hail or snow
- liquid as rain
- gas as clouds, fog, mist or steam
The world water supply
The total amount of water in the world is thought to be about 1,385 million cubic kilometres (1 cubic kilometre equals 1 billion litres). 75% of the earth's surface is covered by oceans, seas, lakes or rivers. In fact, it is estimated that if the earth was a perfect sphere without mountains or hills, the world would be covered in water up to about 2,730 metres deep.
Of all the water on earth, 97% is salty and 3% is fresh water. Of that, 2% is ice mainly at the North and South Poles and in glaciers, leaving approximately 1% of the earth's water suitable for all of our needs.