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Introduction to water. Water. We use it everyday. 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
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Introduction to water • Water. We use it everyday. • 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: • 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 thesaltin 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. Raingardensare 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? • 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!
