- Hi everybody.
And welcome to the first
of our water supply talks.
Today, we are going to be
talking about the water cycle,
groundwater, and stormwater.
My name's Tanya and I am
one of nearly 3000 people
that works for Water Corporation.
We work really hard every day to make sure
that clean, safe, healthy
water arrives in your homes,
schools, and businesses.
So let's pretend we are
going to zip open the street,
and have a look to see
what's really going on
underneath there.
You would find underneath our streets
that there are three
different water pipes.
Each water pipe has got a
completely different job.
The first water pipe is
carrying clean, fresh water
into your homes, schools, and businesses.
If we follow that water
supply pipe all the way back
to its beginning, it would
come out at our dams,
underneath the ground, and in the ocean.
All of that water gets purified,
and then get sent along
that water supply pipe
to your homes, schools, and businesses.
We use that clean water
every day for all sorts
of different jobs.
And as we use it, it gets
really, really dirty.
So that dirty water then goes down
into what we call a wastewater pipe.
Some of you might know the
wastewater pipe as a sewer.
So the wastewater goes
along that wastewater pipe,
and the wastewater pipe,
if we followed it all the way to its end,
it would come out at what we call
a wastewater treatment plant,
where it is purified again,
until it is ready to go back
out into the environment.
The third pipe system,
is the stormwater system.
The stormwater system
catches all of the rain water
on our rainy days,
but also any water that
we might use outdoors,
for example, when you
are washing your car.
(soft upbeat music)
So to understand how all of
those bits work together,
let's have a look at the water cycle.
Now I know you all know the
water cycle really well,
because we started teaching
you the water cycle
when you were in kindy.
And you sung the 'Incy Wincy Spider' song.
Yeah, that's actually a
song about the water cycle.
So the different parts of the water cycle,
we start off with evaporation.
As the water gets heated up by the sun,
it will evaporate up into the sky,
it will cool down as it rises,
and it will condense to form clouds.
Those clouds are constantly
moved around the earth
with the wind, and if the
clouds get heavy enough,
and the conditions are just right,
we will end up with precipitation,
which might be in the form
of rain, hail, or snow.
The water cycle though
is a little bit tricky,
because it doesn't share the
water on earth very evenly.
Some parts of the world are
very dry, like our deserts,
and some parts can be very wet.
Most of Western Australia falls
into the very dry category.
(soft upbeat music)
So also part of the water cycle,
are the three different places
that Water Corporation
uses for your water supply.
Because we get your water out of the dams
from underneath the ground,
and also from the ocean.
Water Corporation's dams were
mostly built by the mid 1970s.
Unfortunately, they don't
supply very much water
into the supply system anymore.
Our climate has changed
a lot since the dams
were first built.
And that means that we've had a number
of very dry winters all in a row.
And so we haven't had
much rainfall going back
into the dams to top them back up.
There is no person who stands
on the side of our dams
with a hose pipe, to fill
them all back up again
for us when they get empty.
And as the dam started
running out of water,
we realized at Water Corporation,
that we would have to find
water, from a different place.
And so we started looking to the water
that sits underneath the ground.
(soft upbeat music)
If you think about it on a rainy day,
the water doesn't just land on the ground,
and fill up, and fill up,
it lands on the ground,
and slowly seeps and soaks deep
down underneath the ground,
through layers of sand and soil,
until the water finally
reaches a really hard layer
sitting underneath the
ground, which is rock.
Luckily for us in Western Australia,
along most of our coastline,
we get a totally awesome
and amazing type of rock
underneath the ground, which is limestone.
Limestone is really the
reason that we are able
to use groundwater for your water supply.
And when you fill up your
water bottle every day,
almost half of your water
bottle, is made up of water
that has come from underneath the ground.
So I'm gonna show you
how absolutely amazing
our limestone is.
So I've got with me a nice
big chunk of limestone,
when I hold it up, I know
you've all seen this before.
If you've been driving along a road
and people have been digging holes,
anywhere along the side of the road,
you will have seen them digging
up big chunks of limestone.
Now let's pretend that
this piece of limestone
is sitting quite deep under the ground,
there are layers of sand
and soil sitting above it,
and it's a rainy day.
So here's my rain cloud.
We'll take a little for the rain cloud.
(lid popping)
Right, so here's my rain cloud.
And as the rain clouds coming along,
we're gonna make it rain,
and the rain is going
to trickle through those
layers of sand and soil,
and watch what happens
when it hits the limestone.
(water pouring)
Right, so I'm pouring a lot of it.
Can you see any dripping off the side?
Is there any coming out of the bottom?
Alright, so it's a very rainy day.
And watch what happens when
I tip the limestone sideways,
everything's vanished, it's disappeared.
Well, it hasn't quite vanished,
it must have gone somewhere.
You all saw me putting the water on there,
but if I turn the rock upside down,
or I give it a big shake,
nothing's coming out.
And the reason for that, is
that limestone on the inside,
looks a bit like a sponge.
There are thousands and thousands
of teeny, tiny little holes inside there,
and as I poured the water
onto the limestone rock,
the water was absorbed or sucked into
all of those tiny little holes and spaces.
It is so good at storing
water, that some of the water
in our limestone under
the ground of Perth,
has been there for millions of years.
Now that this limestone
is filled up with water,
we can call it an aquifer.
So an aquifer is an underground
water storage system.
So that's the easy part,
getting the water into the limestone.
(soft upbeat music)
So the water that sits
underneath the ground,
trapped in all those tiny
little holes in the limestone,
it can be quite tricky to get that out,
especially if we are going
to get it out of the ground
in a sustainable way.
And sustainable means, you are not allowed
to smash the limestone.
So to get the water out of the ground,
we use a machine called a bore.
Many of you will have seen a
bore in your gardens at home,
at school, and even in your local park.
So I'm going to build
a bore for you today,
so that you can understand how it works.
And you can do this later at
home, or with your teacher.
To start off with, I've
just got an empty jug,
and we're going to build
the aquifer in the jug.
Now we need to pretend that
this jug is representing
what's going on underneath the ground.
If we were to cut the ground open,
and pull it apart so that we
could see all of those layers,
that's what we're going
to build into our jug.
This is what we're using for our pump.
You guys will have seen these at home,
you'll find one in your shampoo bottle,
and at the base of my pump,
now this is what we're
going to use as our bore,
at the base of the bore,
I've put a bit of fabric,
and tightened it around the end,
with the bright elastic band.
The fabric at the end of
the pipe, we'll make sure
that we are not sucking
up too many little bits,
which will cause our pump to break.
So that's our bore pump,
and we're gonna pop it just
into our jug over here.
The first layer that we're
going to pop into our jug,
is the limestone layer.
And I've got a whole lot of
limestone rocks over here.
You guys will be able to find these
around your neighborhood too.
We popping those into,
(stones rattling)
base, that's a bit noisy.
Popping those into the base of our system.
(stones rattling)
And you will see, between all
of those bits of limestone,
that there are lots of
holes and gaps and spaces.
On top of that limestone layer,
I'm going to put a whole
lot of little pebbles.
Those ones, and the pebble
layer is going to sit
on top of the big limestone rocks.
(stones rattling)
And you will see that those
peoples have also filled
in a whole lot of the holes and spaces,
between the limestone rocks.
And the final layer that's
going to sit on the top,
is our layer of sand.
So we are gonna pour the sand on the top,
watch how the sand trickles
down into all those little holes
and spaces between the limestone rock,
and all those little pebbles.
(sand gritting)
See how it's trickling down into there
and filling up all those spaces.
So the last bit of our aquifer now,
is to put some water in there.
So this is the water that's
going to form the groundwater,
and get absorbed by all
those limestone rocks.
So we're going to pretend
that it's raining.
And we're going to pour
a whole lot of water
into our aquifer,
and you'll be able to see as
the water trickles down through
all of these layers,
you'll see the layers
getting wet as I pour it in.
(water pouring)
So now it's filled up nicely.
There's lots of water
in our limestone layers.
So now that we filled up our aquifer
with all of that rain water,
we're going to switch our bore pump on.
Now the bore pump's going to
squirt the water out the end.
So make sure that you've got
a little container on the end
to catch that water as it comes out.
I haven't got three hands,
so I'm not going to have one of those.
You can see the water
comes squirting straight
out of my bore pump.
In real life, as the water
comes out of your bore,
it will either feed into your sprinklers,
which will water your gardens,
at Water Corporation,
we've got really big bores
that feed that water off,
and send it to a groundwater
treatment plant to be cleaned.
Right, so are we're going
to pop our bore pump on now.
(water gushing)
Right, so this bore
pump working quite well.
It's sucking water from out of the ground,
from out of the limestone
and squirting it out the top.
If you really want to make
a mess of your aquifer,
you can even add a few
little colored droplets,
just like those ones.
Pop a few of the droplets in as well.
And those ones will represent
things like pollutants.
Now, we're going to talk
about that a little bit later
in the talk, and how those
pollutants affect our stormwater
and our groundwater systems.
So you can pop a couple of droplets
on the top there as well,
and pretend that those are pollutants,
and watch how they get
drawn down into the aquifer,
and will affect the quality
of the water supply in there.
So that's our aquifer experiment.
And if you don't do one at school,
you can maybe make one at
home as part of your homework.
(soft upbeat music)
One of the things with groundwater,
is that we need rain
to keep topping it up.
If we've got lots of bores
going into the ground,
sucking water out of
the ground constantly,
we need the same amount
of rain during winter,
to keep that water level
underneath the ground stable.
But as I've mentioned, we not
getting nearly as much rain
in most of Western
Australia as we used to.
And so the water underneath
the ground is also decreasing.
That meant that Water Corporation
had to be very innovative.
We had to come up with a source of water,
that did not depend on the rain.
And that's why we built a
very large desalination plant
in 2006.
The desalination plants,
we've got two of them now,
they supply purified seawater,
into our water supply as well.
So the desalination
plants takes salty water
out of the ocean, clean
it, remove the salt,
viruses, bacteria, and
then that clean water
is also added into our
water supply system.
(soft upbeat music)
And now we're gonna talk
about what your roles
and responsibilities are, to help us care
for the water supplies that
we use for you every day.
Remember when we zipped open the street,
one of the pipes we found under there,
was the stormwater pipe.
So the stormwater pipe
catches all of the water,
that lands up on our streets,
trickles down of our driveways,
and comes out of our
gardens and disappears down
the stormwater drains, that
you guys will have seen
when you're walking or riding to school.
The stormwater drains have
got a very different system.
There is no factory at the
end of the stormwater drain.
Any water that comes off your garden,
washes off the streets, that
water lands up directly back
in the environment again.
And depending on where you live,
that water might land up in
a river, a lake, a wetland,
or even back in the ocean.
Maybe you can have a
think after school today,
about where your stormwater might end up,
and figure out where your
closest water way is.
(soft upbeat music)
The stormwater as it moves down
through the stormwater pipes,
collects everything that
we might be using outdoors.
So think of the many
jobs that we do outdoors
that might contribute to pollutants
entering our stormwater drain.
I'm sure you've all washed a car before,
well, I hope you have.
And when you were washing your car,
you would have used some soap.
Now, if you've been washing
your car in the driveway,
some of that soap will
trickle down your driveway
into the street and into
the stormwater system.
Have a think about the number of poisons
we use in our gardens.
We don't like bugs and
beasties eating our vegetables,
and our lettuces and our
roses in our gardens.
And so we have a number
of different poisons
to get rid of those pests,
and those poisons we
generally call, insecticides.
We also don't like weeds very much.
And so we have lots of
different kinds of weed killers,
that we also use in our gardens.
If we use a lot of those,
then some of the excess,
will also wash into the streets
and enter our stormwater system.
Don't forget about one
of the worst pollutants
that lands up in our stormwater, dog poo.
If you've got a dog, we
need you to make sure
that you have plenty of dog bags
when you are taking your dog for a walk,
so that if it does more than one poop,
you are well-prepared to pick
up the second one as well.
The problem is, when
those sorts of pollutants
enter the stormwater system,
they can affect the
natural fauna and flora,
the plants and animals
living in those waterways
will be very badly
affected by the pollutants
that come from our gardens
and from our homes.
Now we've got two pictures of a lake.
Imagine we went to a
beautiful, clean, healthy lake.
The water is lovely and pure.
There's all sorts of trees, and reeds
in the middle of the lake.
We popped our hats on, took a
sandwich and sat in the shade
of those trees for a
while, really quietly.
(ducks quacking)
As we sat there, we would become aware
of all sorts of amazing creatures
that were living around us,
they would be creatures that
were living in the lake,
creatures that were living and
flying around in the reeds,
you'd probably hear a couple of frogs.
And if you looked up into the trees,
you would see that they were birds
and all sorts of creatures that live up
in those trees as well.
And that's the kind of ecosystem
that we want to encourage.
We want to be able to go to places
where we can see our
beautiful native wildlife.
But if we add too many
stormwater pollutants
into the system, and
those wash into a lake,
they can make all of those
amazing creatures and plants,
really sick, and often they can even die.
For example, if you are
using soap to wash your car,
and you use a lot of soap that enters
the stormwater system, that's soap affects
the outer slimy skin of the frogs.
If you've ever picked up a frog,
you will know that that
outer skin feels very slimy,
and that slime is there for a reason.
It protects the frog.
And as the soap comes into the system,
it destroys that slimy
layer on the top of a frog,
and frogs can get really, really sick,
if that happens to them.
As cars drive along the street as well,
if they've got an oil leak,
the oil drips into the street,
washes off the street on a rainy day.
And if that enters a wetland or a lake,
and there are ducks and
water birds that live there,
the oil gets stuck in their feathers,
and they can no longer
fly particularly well.
So oil coming off our streets
can be a really bad form of pollutants.
What about the dog poop?
Well, dog poop has got
really bad bacteria in there,
and it's got lots of nutrients.
And when those land up
in our stormwater system,
and land up in a lake or a wetland,
they can also cause a
huge amount of damage,
especially if there's
some fish, frogs, yabbies,
crabs living in that water,
they will get sick from the bacteria
and the nutrients coming
from a doggy poop.
(soft upbeat music)
And by their definition,
pesticides and herbicides,
kill bugs and plants.
And if we use too many of those poisons,
they will really badly
affect the insect life
and the plant life at our wetland.
So why am I telling you
all of this bad news?
Well, it's very simple
for us all to make sure
that those pollutants don't
enter the stormwater system.
An easy one of course, is to make sure
where you've got your doggy poop bags,
when you take dogs for the walk.
But part of your homework today,
is to have a look around your
homes and in your gardens.
And you'll probably want
to take an adult with you,
and have a look at the different products,
that you use.
Are your products
environmentally friendly,
and if you're not sure what
that means, ask an adult,
to read the labels on the
back of your products.
Have a look at your dishwash soap,
does it say on there that it
is safe for the environment?
There are all sorts of amazing pesticides,
and herbicides that we
use today in our gardens,
that are not poisonous at all.
I use a weed killer at home,
which is actually just
made out of vinegar.
And vinegar is rotten grapes,
and grapes are natural.
So if we use those sorts of herbicides,
and pesticides around our homes,
then we'll know that we
are protecting the wildlife
on the other side of a stormwater system.
So today, hopefully you will
understand how important it is,
for you to protect our waterways
through the stormwater system.
If you're not convinced,
I would suggest you make some stormwater.
Have a think about the different products
that you might use around your home,
and your adults at home
can help you with this,
get a plastic tub, half
fill it with water,
and then start adding some
of those products in there.
See if you've got some
soap from washing your car,
and pop a squirt of that in,
pop in a few different
pesticides and herbicides,
I don't think you'd want to
put a real doggy poop in there,
but you could use a bit
of play-dough instead,
and have a look at how that
water starts changing color,
how the smell changes,
have a look some things
will float on the top,
some things will sink to the bottom,
but just remember that
if those are the products
you're using in your home,
they may very well end up
back in the environment again.
So today I've outlined some of the jobs
that Water Corporation does for you,
and some of the jobs
that you need to do too,
to protect all of those waterway systems,
that we get your drinking
water from, every day.
And to end off, I am
going to give you just
an extra little bit of homework.
So as I mentioned, one of your
jobs will be to walk around
your home with an adult,
and have a look at all
the different products
that you use around your home.
And next time an adult goes shopping,
maybe try and convince them
to buy the environmentally
friendly versions,
of whatever you use in your homes.
I also want you to become more aware,
of how much water you use in your home.
Remember where it's come from,
and how hard Water Corporation is working,
to make sure that you do
get fresh water every day.
So your jobs are really
important, to help us,
do our job even better.
And I want to thank you all
for listening so beautifully today,
I hope you've learned something,
and I hope that you will go home,
and teach that something
to someone at home.
(soft upbeat music)
