Introduction to water
Water. We use it everyday.
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We drink it
Wash ourselves (and our pets) in it
Cook with it
Swim in it
Water our plants with it
Put out fires with it
Use it recreationally
Eat food from it
Flush our toilets with it
We need water to survive!
So, where does all this
water come from?
Where does water come from?
There is a lot of water on Earth.
Imagine a 1 litre jug of water.
You would need
1,260,000,000,000,000,000,000 1 litre jugs to
hold all of the water in the world.
Out of all the water on the planet, 97 percent
of it is in our oceans.
Water in our oceans
Earth has five oceans. Together they cover over 70
percent of the planet’s surface.
These oceans are also very deep. The average
depth of oceans in the world is over 3km!
If there is so much water in the ocean – why do we
need to save water?
It has to do with what is in the water in the ocean.
What is different about water from the ocean,
compared to water from a tap?
That’s right! Ocean water has salt
in it, which means we cannot drink it.
Fresh water
This means, only 3 percent of the worlds
water is fresh (not salty) water.
Of that 3 percent, 2.97 percent of the fresh
water in the world is frozen in polar ice caps
and glaciers, or found in groundwater.
This means that only 0.03 percent of all the
water in the world is fresh, and available for
us to drink.
And we use that 0.03 percent for everything,
including flushing our toilets and washing
our cars!
Our water has been around for millions of years
There is something else that you may not know
about water.
The water we drink today, has been around for
millions of years! Since before the dinosaurs!
All of the water on Earth is recycled (just like we
recycle paper, plastic and other items).
Except water is recycled through nature. We call
this the Water Cycle.
So, how does the Water Cycle work?
The Water Cycle
The Water Cycle is the ‘life cycle’ of water.
There is no start or end to the water cycle, it
simply keeps going and going.
During the water cycle, water changes state.
This means it changes from a liquid (water), to a
solid (ice), to a vapour (steam), within the cycle.
Let’s take a look at the different stages of the
water cycle.
See if you can figure out which state the water is
in at each stage.
Precipitation
Precipitation (also known as rain), is a
stage of the water cycle we are all familiar
with.
When it rains, water falls from the clouds
and onto the ground (or into the ocean).
When rain lands on the ground, it either
soaks into the soil, or runs off the surface.
If rain falls over the ocean, it joins the
water in the ocean, just as it would a river
or a lake.
Infiltration
When it rains over (permeable) land, the water that
falls onto the ground soaks into the soil.
This is known as infiltration.
Infiltration of water into the soil helps plants to get
water from the soil, which helps them to grow.
Water which is not taken up by plants soaks down
further and becomes groundwater.
What happens to the water once the trees absorb it?
Transpiration
When the trees have absorbed the water from
the soil, they bring it up through their roots and
push it out to the tips of their leaves.
When the sun is shining and the atmosphere is
warm, the trees transpire (sweat) water, just like
we do when we are hot.
This is called transpiration.
This water then evaporates in the atmosphere
and turns into water vapour (just like the steam
of a boiling kettle).
The water then travels up into the atmosphere as
water vapour.
Condensation
As the water vapour travels higher into the
atmosphere it gets much colder.
This change in temperature slows the water
vapour down, and brings it closer together,
causing it to form water droplets.
Just as the steam from a hot shower forms
water droplets on the bathroom walls once
the room cools down.
This is called condensation.
These water droplets accumulate in the
clouds. When the clouds can no longer hold
the water – it rains.
Precipitation
Just as before - it rains!
But this time the rain falls on a surface
that is impermeable, such as concrete.
This means the ground will not soak up
the water as it did before.
What happens to the water if it cannot
soak into the ground for the trees to
absorb?
Surface runoff
Precipitation that does not soak into the ground, sits
on top of the ground.
This is called surface runoff.
Surface runoff can also happen when there is a lot of
rain and the soil is water logged.
This happens a lot in cities where there is less
permeable ground (such as grass and soil) and more
impermeable ground (such as footpaths,
roads and bricks).
Stormwater and Litter
If water is unable to soak into the ground, it runs
along the gutters and into the stormwater drains.
As it travels towards the drains it collects litter
that has been left on the footpath or road.
This litter includes:
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Food wrappers
Oil from cars
Animal waste
Cigarette butts, and
Anything that does not belong in the
waterways
And it all goes directly to the stormwater drains.
Stormwater and Litter
The openings to stormwater drains are often
large to allow a lot of water to come in when
it rains.
This means that any litter that is near a
stormwater drain is likely to end up in the
stormwater.
Why do you think this might be a problem?
Litter in the ocean
Stormwater drains often go directly to the
ocean.
This means, any litter that makes its way into the
stormwater drains, will end up in the ocean.
This is very dangerous for the animals that live
there.
Marine animals such as turtles can confuse our
litter for pieces of food, and swallow them
accidently. This can be fatal for them.
How can we help reduce this from happening?
We can pick up any litter we see on the ground!
Evaporation
Once the water reaches the ocean it will stay
there until the atmosphere above the ocean is
warmer than the ocean water.
When the air is warmer, the ocean water will
start to change state, back into water vapour
and rise back up into the sky.
This is called evaporation.
As the salt in the ocean water is too heavy to
evaporate, it will stay in the ocean.
This means that the water vapour
will once again be fresh water!
Condensation
Just as before, the water vapour will continue
to rise up into the atmosphere.
As the vapour rises it will collect dust and dirt
that is in the atmosphere.
It is this dust and dirt that helps clouds form.
Clouds are a combination of dust and dirt,
water vapour and a change in atmospheric
pressure.
When the clouds are full of water again, it
rains.
Precipitation
Rain doesn’t always fall on land. In fact,
rain is more likely to fall into the oceans,
rivers and lakes than it is to fall onto land.
When rain falls straight into our rivers, we
can use it for drinking water.
We call water that is safe for drinking,
potable water.
To use this potable water, we need to
store it, and filter it, so it is clean.
How can we store a lot of water?
Storage dams
Storage dams hold water that has made its
way into rivers and lakes when it rains.
We use storage dams to keep the water in
one area (just as we use a water bottle to
bring water around with us, we use a
storage dam to keep the water in one place
so it is easier to use).
Storage dams are very important, especially
when rivers flow through many towns and
states. We have to ensure there
is clean water for everyone.
Potable water
Water from storage dams is filtered and sent along
water pipes to our schools and homes.
Australia has some of the highest quality potable
water in the world – we are very lucky.
Many countries do not have readily available access
to potable water. The means they must travel long
distances to get clean water, or drink non-potable
water which can make them sick.
In Australia, we use potable water for many things
we don’t need to, such as flushing our toilets.
Instead of using potable water for these things, we
can use recycled water.
Sewage water
Sewage water is what we call water once it
has been flushed down the toilet.
Although we use potable water to flush our
toilets, once it has been in the toilet, it is
considered sewage water.
When we flush the toilet the sewage water
goes through the sewerage (sewage pipes)
and ends up at a Water Treatment Facility.
Most countries use recycled water to flush
their toilets – Australia is one of the last
countries that still uses potable water to
flush our toilets.
Water Treatment Facility
When water makes its way through
the sewerage it ends up at the Water
Treatment Facility.
The Water Treatment Facility filters
the sewage water so that it is safe
enough to go back into the waterways.
This takes a lot of filtering, but by the
last stage of the treatment, it is almost
as clean as potable water!
Washing our clothes
Sewerage isn’t the only form of pipes that
take water from our house.
Some households have special pipes
installed that take their soapy water from
their washing machine and their bathroom
sink and send it straight to their garden.
This helps reduce the build up of nutrients
such as phosphorus (that are found in some
detergents) from reaching our waterways.
Greywater
This soapy water is known as greywater.
Greywater is not potable water as it can
not be used for drinking (the soaps in it will
make us sick).
It can however be used for other purposes
such as watering your (non-edible) garden
plants.
Using greywater on your garden saves the
potable water from the tap for drinking!
Raingardens
Another way to reduce excess nutrients
and litter reaching our waterways is by
building a raingarden.
Raingardens are designed to filter
pollutants out of the stormwater before
they reach the drains and waterways.
To do this, raingardens are layered with
many layers of fine sand and other
materials to trap pollutants before the
water reaches the groundwater.
Groundwater
When the water soaks deep into the
soil it forms a pool underground.
This is called groundwater.
Groundwater is very important.
Trees use groundwater to get the
water they need to grow and people
use ground water to help irrigate
farmland for agriculture.
The Water Cycle
All of these steps make the water cycle function.
As you can see, without the water cycle there
would be no rain, no oceans, no plants, no rivers,
and no animals (this includes people too!).
We need the water cycle to survive.
To make sure the water cycle is able to work as
well as it can, we also need to look after our
waterways so they stay clean and healthy.
What kinds of waterways do we have in
Brimbank?
Caring for our local waterways
Did you know that in Brimbank we have many creeks, rivers
and wetlands?
What can we do to help keep our creeks, rivers and wetlands
clean?
We can:
• Pick up any litter we see
• Pick up dog poo when we are walking our dogs, and
• Avoid using washing detergents with phosphorus in them
We could also reduce the amount of water we
use at home and at school to ensure our
waterways stay full.
Why is it important to save water?
Australia is the driest inhabited continent in the world!
This means we get very little rainfall compared to other
countries.
Even when we are not in a drought, it is important to
use water wisely.
This doesn’t have to mean showering with buckets in
your shower – but it does mean being thoughtful when
using water, and only ever using the amount of water
you need.
What are some ways we can reduce the amount of
water we use?
Reducing water use
There are lots of simple things that you can do
to reduce your water use.
Keep an eye out (and tell someone about):
• Dripping taps, and
• Leaking pipes
Remember to:
• Have 4 minute showers, and
• Turn the taps off while we brush our teeth
• Wash the car with a bucket of water
instead of the hose
• Be water wise when using water
Being water wise at school
What can we do to be water wise at school?
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Put buckets outside when it is raining to
collect rain water for the garden
Wash our paint brushes in a bucket
instead of using a running tap
Tell a teacher if a toilet or tap won’t stop
running
Pick up any litter that you see so it
doesn’t enter the drain
And remember – we need water to survive,
so let’s be wise with it!