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THE WATER CYCLE A HUNTER WATER PUBLICATION
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the water cycle - Hunter Water · people all around the world interrupt the water cycle for their use. when water falls onto the earth people catch it and store it. the area which

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Page 1: the water cycle - Hunter Water · people all around the world interrupt the water cycle for their use. when water falls onto the earth people catch it and store it. the area which

the

water cycle

a hunter water publication

Page 2: the water cycle - Hunter Water · people all around the world interrupt the water cycle for their use. when water falls onto the earth people catch it and store it. the area which

Do you ever think about water when you turn on the tap? could you imagine what it would be like without water?

we need it for drinking, cooking, washing, for toilets and showers. we use it for watering gardens, in swimming pools, for washing cars and at farms and factories.

without water there would be no life at all.

More than two thirds of the earth’s surface is water, but only a small amount of the water on earth is freshwater we can use.

Most of the earth’s water is salt water found in the sea, which cannot be used for drinking or growing crops. Most of the world’s freshwater is locked in the polar ice caps, glaciers, atmosphere and soil.

a small amount of freshwater is found in rivers, lakes and groundwater, some of which people can use.

water is recycled through the water cycle.

it is called the water cycle because the water makes a journey from the sea up into the sky and from the sky back to the sea again, in a circular motion.

Water in our Life

2 www.hunterwater.com.au

Page 3: the water cycle - Hunter Water · people all around the world interrupt the water cycle for their use. when water falls onto the earth people catch it and store it. the area which

The Water Cycle

label the illustration above to show the processes of the water cycle with the following words:

• Evaporation• Transpiration• Condensation• Precipitation

evaporation water from the sea rises into the sky during a process called evaporation. we do not see the water rising because the water has turned into water vapour which is almost invisible. water vapour is just like steam from a boiling kettle.

transpiration water also rises up into the air from plants. plants take up water through their roots and pass moisture back to

the air through their leaves. this is called transpiration.

condensation in the sky, when the air cannot hold all the water vapour it contains, the extra vapour turns into tiny droplets of water and appears again as fog, mist or clouds. this process is called condensation. when these droplets become too heavy they fall.

precipitationwater falls from the sky as rain, snow or hail, this is called precipitation. the water flows into creeks and rivers and then into the sea. water can also soak underground and be stored naturally in underground basins. the underground water and water from rivers ends up in the sea, and so the cycle begins once again.

the Water CyClE

3 www.hunterwater.com.au

Page 4: the water cycle - Hunter Water · people all around the world interrupt the water cycle for their use. when water falls onto the earth people catch it and store it. the area which

people all around the world interrupt the water cycle for their use. when water falls onto the earth people catch it and store it.

the area which catches and stores water is called a catchment. in many parts of the world people build dams to store water.

hunter water is responsible for supplying the lower hunter community with a reliable and healthy supply of water.

besides small water supply services at anna bay and lemon tree passage, there are three main sources of water for people who live in the lower hunter.

chichester damchichester Dam is the oldest dam currently in use in the hunter and was completed in 1926. it was constructed on the chichester river below the junction of the wangat and chichester rivers. the catchment covers an area of 197km2 and includes extensive forests and high mountains. the catchment area is unaffected by pollution caused by human activities. the dam was constructed of hundreds of interlocking units of concrete. when one block was finished, the formwork was raised ready for the next, until it reached its final height of 40 metres. the dam can hold 21,500 million litres of water.

tomago sandbedsthe second source of water in the hunter is drawn from an underground aquifer known as the tomago Sandbeds. tomago is the aboriginal word for sweet water. the sandbeds retain water which seeps through the sand, allowing it to accumulate in the sand. the catchment covers an area of 130km2. water was first taken from the sandbeds to supply customers in 1939.

grahamstown damthis third water supply source has been operating since 1960. Fresh water is pumped from the williams river for storage in Grahamstown Dam. it is the largest water storage facility in the area and can hold 152,000 million litres of water.

Water Supply and StorageWater suPPly & sToragE

4 www.hunterwater.com.au

Page 5: the water cycle - Hunter Water · people all around the world interrupt the water cycle for their use. when water falls onto the earth people catch it and store it. the area which

water treatmentall water supplied from these sources undergoes treatment to make it safe and healthy to drink. the standards for drinking water are set by the national health and Medical research council.

water is filtered to remove impurities and chlorine is added to kill any bugs. Fluoride is added to protect our teeth. to make sure our water is always healthy to drink, water samples are regularly tested by scientists.

water delivery systemhunter water maintains 4,400 kilometres of water pipes, 73 water reservoirs and 77 pumping stations

which assist in the supply of water to houses, shops, factories, schools, hospitals and sports fields in the lower hunter.

Water TrEaTmEnT & dElivEry

5 www.hunterwater.com.au

Page 6: the water cycle - Hunter Water · people all around the world interrupt the water cycle for their use. when water falls onto the earth people catch it and store it. the area which

Water ConservationWater Supply and StorageWater suPPly & sToragE

around the world...in many countries people do not have a water supply to their homes, they do not have taps, showers or flushing toilets.

in fact, three quarters of the world’s children live in areas where water is scarce or unsafe to drink. because water is in short supply, and is not piped to homes, people have to collect water from local creeks or wells.

each day women and children walk to fetch the water for their family. Some walk many kilometres and carry it back to their villages in buckets, barrels or pots.

often water that is used for drinking is

also used for washing, cleaning and for getting rid of waste. this means that many people become sick or die from drinking unclean water. we are lucky to live where there is a reliable supply of clean and healthy water.

water is a precious resource which should not be wasted. in some areas where there are large dams, like chichester and Grahamstown Dams, people think there is plenty of water.

this is not always true. we rely on rain to keep our dams full and in times of drought it may be months before our water supplies are replenished. this is why we all need to look after water and use it wisely.

6 www.hunterwater.com.au

Page 7: the water cycle - Hunter Water · people all around the world interrupt the water cycle for their use. when water falls onto the earth people catch it and store it. the area which

each person in the hunter uses about 200 litres of water every day. to protect our supplies there are a number of ways we can all conserve water every day:

simple things we can all doput the plug in the sink when washing vegetables•take shorter showers or have a shallow bath•only use the washing machine for full loads•turn the tap off while you brush your teeth•use buckets of water to rinse off your car•check taps, hoses and pipes for leaks•

ideas For the garden install drip systems or microsprays to water plants•water the roots of plants and trees, not the leaves•use a good mulch in the garden to retain moisture•Sweep paths instead of hosing them with water•water your lawn and gardens in the morning•plant natives, which require less water•

water saving devicesbuy efficient appliances•

(check the welS star rating)install water saving shower heads•use trigger nozzles on your hoses•install aerators on your taps•install dual flush toilets•install a rainwater tank•

Water ConservationWater Supply and StorageWater saving TiPs

7 www.hunterwater.com.au

Page 8: the water cycle - Hunter Water · people all around the world interrupt the water cycle for their use. when water falls onto the earth people catch it and store it. the area which

WasteWater treatmentWasteWater treatment

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what happens to water after it goes down the drain or is flushed down the toilet?

this water is called wastewater or sewage and while it is mostly water, it also contains other substances including:

•soapsanddetergents•organicmateriallikepooandurine•householdcookingoilsandfats•chemicalsandfertilisers•micro-organisms,bacteria,viruses•leftoverfoodscraps•greaseandoils•heavymetals

wastewater must be carefully treated to remove the unwanted wastes before it is returned to the environment.

wastewater is collected by a maze of sewer pipes and transported to one of hunter water’s 18 wastewater treatment works.

the first stage of treatment involves screening to remove all large objects such as paper and plastic. Sewage then passes through the grit trap to remove particles such as sand and soil.

to remove harmful organic matter, wastewater is biologically treated. Varioustypesofmicro-organisms(good germs) are cultivated at the wastewater treatment works (their technical name is activated sludge). they rely on organic matter (bad germs) for their food.

in effect, the good germs eat the bad germs. to separate the good germs, the wastewater is transferred to clarifiers where the good germs sink to the bottom and are returned to the biological treatment process for more food. this leaves clear water (which is called treated effluent or recycled water) that can be safely returned to waterways or reused.

www.hunterwater.com.au

Page 9: the water cycle - Hunter Water · people all around the world interrupt the water cycle for their use. when water falls onto the earth people catch it and store it. the area which

Water ConsErvaTion

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there are two products from the wastewater treatment process, recycled water and activated sludge.

recycled water is the clear treated liquid, mentioned earlier. while this liquid is not safe enough to drink, it can be substituted for drinking water for the following:

making electricity at power •stationswashing coal at local coal mines•irrigating trees at tree plantations•watering bowling greens•helping to construct roads•watering golf courses•watering farm crops•

activated Sludge is the good germs referred to in the previous section, which are returned to the biological process.

often there is an excess of good germs which cannot be returned to the biological process. the excess sludge is taken to a sludge drying presswhereitisdriedtoformasoil-like substance called biosolids, which can be recycled.

biosolids have been used on projects in our area as a substitute for fertilised topsoil, including:

establishing vegetation at mines•establishing gardens•improving agricultural areas•composting and landscaping•

www.hunterwater.com.au

Page 10: the water cycle - Hunter Water · people all around the world interrupt the water cycle for their use. when water falls onto the earth people catch it and store it. the area which

stormWater treatment

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Stormwater is the water that falls as rain onto hard surfaces. rain which falls on land, roofs, roads and other surfaces can collect more than water as it travels to the stormwater drains.

rubbish and other pollution in the path of the runoff is picked up and discharged into stormwater drains which eventually lead to waterways, such as creeks, rivers, harbours and beaches.

Stormwater pollution can include:oil, grease and rubber from roads•fertilisers and pesticides•animal droppings•litter and rubbish•carwashing detergents•

Stormwater, unlike wastewater, is not treated to reduce or remove pollutants before it flows into waterways. in times of heavy rain, discharge at stormwater outlets can seriously affect water quality.

Stormwater drains are dangerous places during heavy downpours. the force of fast flowing water can carry large objects such as shopping trolleys and branches with great speed and cause serious damage.

Stormwater drains can also cause injuries when dry due to their steep walls and hard concrete surfaces. You should never walk, ride or play in stormwater drains.

www.hunterwater.com.au

Page 11: the water cycle - Hunter Water · people all around the world interrupt the water cycle for their use. when water falls onto the earth people catch it and store it. the area which

Keeping Waterways CleankEEPing Waterways ClEan

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never put oils, grease, fats, paints, chemicals, cotton waste, plastics, cigarette butts, pesticides, medicines or rubbish down the drain or toilet.

Some of these pollutants upset the good germs at our treatment plants, resulting in poor treatment of the wastewater.

other tips to our protect waterways

• Dispose of litter in waste or recycling bins

• Don’tletgrassclippings,dirt,leaves or animal droppings wash into drains

• Usephosphorusfreeproductswhere possible and minimise fertiliser use on pastures, lawns and gardens

• ContactHunterWatertodisposeof household chemicals on 1300 657 657

• Contactyourlocalcounciltodispose of sump oil and oil filters

• Useasinkstrainerathome

• JoinaLandcareorCoastcaregroup

• Washyourcaronthelawnoratacommercial car wash where it is recycled

• Useabroomnotahosetosweepup leaves and rubbish, then put it in the bin or compost

• Fixoilleaksinyourcar

• Plantgroundcoverswheresoilisexposed

• Avoidspreadingfertiliserwhenyouknow rain is due – nutrients cause algae growth in waterways

• Trynaturalmethodsofpestcontrolrather than using toxic chemicals

• Cleanupwater-basedpaintsonthegrass,notoverthedrain.Oil-based paints should be dried out and put in the bin

• Choosesoft,permeablesurfaceswhen landscaping to decrease stormwater runoff

• Installarainwatertank.You’llreduce runoff and have a sustainable source of water for your garden

• Carryaplasticbagtopickupafteryour dog

www.hunterwater.com.au

Page 12: the water cycle - Hunter Water · people all around the world interrupt the water cycle for their use. when water falls onto the earth people catch it and store it. the area which

Hunter water Corporation

36 Honeysuckle drive

nEwCasTlE nsw 2300

Po Box 5171

HrmC nsw 2310

t: 1300 657 657

e: [email protected]

i: www.hunterwater.com.au

Printed on recycled paper

may 2009

Cover photo: annette Blattman