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Water properties


Water is the most common substance on earth.
  • Water is the most common substance on Earth.
  • There is about 1,358 million cubic kilometres of water on Earth.
  • Water is the only substance on Earth found naturally in three forms: solid, liquid and gas.
  • Water is unusual because its solid form, ice, is less dense than the liquid form. This is why ice floats.
  • Water freezes, to become ice, from the top down.
  • Water freezes at zero degrees Celsius.
  • Water vaporises at 100 degrees Celsius.
  • Once evaporated, a water molecule spends 10 days in the air.
  • Pure water (solely hydrogen and oxygen atoms) has no colour, no taste and doesn't smell of anything.
  • Pure water has a neutral pH of 7, which is neither acidic nor basic.
  • Water is made of tiny molecules. Each one is so small that you can't see it even with the most powerful microscope.
  • The same water that existed on the earth millions of years ago is still present today.
  • Water dissolves more substances than any other liquid.
  • Wherever it travels, water carries chemicals, minerals, and nutrients.
  • Water consists of molecules, each of which has three atoms: two hydrogen atoms and an oxygen atom that are bound together by electrical charges.
  • In a 100 year period, a water molecule spends 98 years in the ocean, 20 months as ice, about two weeks in lakes and rivers and less than a week in the atmosphere.
  • A litre of water weighs approximately 1 kilogram.
  • The droplets of water vapour that make clouds are 1,000 times smaller than a raindrop.

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    Water in our bodies

  • About 66% of the human body is water. Some parts of the body contain more water than others.
  • 80% of your brain and 25% of your bones are made up of water.
  • An average adult has 37 litres of water in their body.
  • Human blood is 83% water.

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    Water in History


    A painting by J. Skinner Prout of the Tank Stream in the 1840's.
  • Sydney was chosen for the first European settlement in Australia because of its deep harbour and freshwater from the Tank Stream.
  • In 1800, Busby's Bore piped water from Lachlan Swamps to Hyde Park where it was transferred to water carts.
  • Sydney Water began as the Board of Water Supply and Sewerage in 1880.
  • From 1934-1942, Sydney experienced a severe drought that lasted eight years and almost caused water supplies to run out.
  • Ancient Egyptians treated water by siphoning it from the top of huge jars after allowing the muddy water from the Nile River to settle.
  • Hippocrates directed the ancient Greeks to boil and strain water before drinking it.
  • The ancient Greeks invented the first piped showers in AD 300.
  • The oldest dam still in use is in Orontes in Syria, and was built in 1300 BC.
  • The first cities to have water pipes were in the Indus Valley in south Asia.
  • The first known sewer pipe was built in about 3,000 BC in the Orkney Islands of Scotland.

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    Water and health


    Drinking water is important for health.
  • The human body can only survive five to seven days without water, but about a month without food.
  • Once you drink water, it leaves your stomach in about five minutes!
  • A person should drink two litres of water a day to help them be healthy.
  • We drink an average of 75,000 litres of water in our lifetime.
  • Water regulates the temperature of the human body. If you have a fever, drink lots of water.
  • Water removes waste from your body.
  • Your drinking water may be fluoridated to help prevent dental cavities.
  • Water can cause serious health problems if contaminated by bacteria or other microorganisms.
  • In most Australian cities and towns, tap water is treated so people don't get sick.

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    Sydney Water's operations

  • Sydney Water's area of operations covers Sydney, the Illawarra and the Blue Mountains.
  • Sydney Water supplies water to over 4 million people.
  • Sydney Water is Australia's largest water utility with about 3,200 staff.
  • Sydney Water's area of operations covers around 12,700 square kilometres.
  • Sydney has a very large water storage, but a highly variable rainfall.
  • The four main parts of the NSW Government's plan to secure our water for life are: dams, recycling, desalination and water efficiency.
  • The desalination plant can supply up to 15% of Sydney's water supply.
  • The desalination plant can supply up to 250 million litres of drinking water a day!
  • Sewer mining involves tapping into wastewater on its way to a sewage treatment plant and treating it for local reuse.
  • Sydney Water treats water and distributes it through about 21,000 kilometres of water pipes
  • Sydney Water's pipes would stretch from Sydney to Los Angeles and back if laid end to end.
  • Sydney Water supplies over 1.3 billion litres of water to over 1.7 million homes and businesses each day.
  • Drinking water is tested and monitored at every stage of the supply system.
  • Sydney Water tests water straight after it is treated, in the pipes and at the tap.
  • Sydney Water has 261 reservoirs and 156 pumping stations to help distribute water to its customers.
  • Sydney Water collects and treats over 1.5 billion litres of wastewater a day.

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    School water use


    Schools in Sydney Water's area of operations use 7,790 million litres of water a year.
  • There are over 1,500 schools in Sydney Water's area of operations.
  • The NSW Department of Education and Training has set a water saving target of 15% for all its government schools.
  • Schools in Sydney Water's area of operations use 7,790 million litres of water a year.
  • Schools use about 6% of all non-residential water in greater Sydney.
  • A water efficient primary school uses less than nine litres of water a student a day.
  • A water efficient high school uses less than 12 litres of water for each student a day.
  • Up to 70% of water used by schools can be lost through leaking taps, toilets or pipes.
  • An average primary school spends about $5,150 on their water bill and an average high school spends about $5,300.
  • When we pay for water, we also pay for the sewage we discharge.
  • One drop a second from a leaking bubbler wastes 7,000 litres of water a year.

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    Quantities of water on Earth


    Most of the Earth's water is found in oceans and seas.
  • 97% of the Earth's water is saltwater found in oceans and seas.
  • Of the three per cent of water that is freshwater, only one per cent is available for drinking.
  • Two per cent of the Earth's water is frozen.
  • Over 90% of the world's supply of freshwater is located in Antarctica.
  • About 71% of the Earth's surface is water.

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    Fun facts

  • The automatic dishwasher was invented in 1889.
  • Making recycled paper instead of new paper uses, on average, 64% less energy and 58% less water.
  • Construction workers' hard hats were invented when the USA built the Hoover Dam in 1933.
  • The phrase 'raining cats and dogs' began in 17C England. During heavy rain, many cats and dogs drowned and their bodies would float through the streets.
  • Cows bred for their meat need 40 to 140 litres of water a day.
  • A sheep needs 4 to 10 litres of water a day.
  • Cows bred for milk need 147 litres of water a day.
  • One litre of milk is about 86% water.
  • It takes 148,000 litres of water to make a new car, including its four tyres.
  • A horse needs 40 to 50 litres of water a day to survive.
  • 60% of the world's desalination plants are in the Middle East.
  • 2.5cm of rainwater can give about 38.1 cm of dry, powdery snow.
  • The largest snowflake ever recorded was 38 cm across. It fell in the United States in 1887.

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