Ausgeology. Years 3 to 10 lessons

Year 4 Science · AC9S4U02

The water cycle.

Water never stays still. It rises into the sky, falls as rain, runs over the land and flows into the sea. Then it does it all again. The water in your drink bottle has been a cloud, a river and an ocean, many times over.

Illustration
Sea, sky and land, all in one picture. Can you find the sun, the clouds, the rain, the lake, the river, the town’s water tank and the water hidden underground?
Evaporationwater goes up, as a gas you cannot see
Condensationthe gas turns back into tiny drops
Precipitationrain, hail or snow falls from clouds

What we are learning

Where water comes from, and how it moves between the sky, the land and the sea.

I can

  • 1name places where water is found, and say where my tap water comes from.
  • 2explain evaporation: water turning into an invisible gas, faster when it is warm or windy.
  • 3explain condensation: water vapour turning back into drops when it cools.
  • 4explain precipitation: water falling from clouds as rain, hail or snow.
  • 5describe how water moves round and round, through the sky, over the land and into the sea.

Australian Curriculum v9, AC9S4U02: “identify sources of water and describe key processes in the water cycle, including movement of water through the sky, landscape and ocean; precipitation; evaporation; and condensation”

Printable activity

Puddle watch and bag watch

Chalk around a real puddle and measure it through the day, make a water cycle in a bag and draw what it does for three days, then label the cycle. The same links are at the end of the lesson.

Activity sheet (PDF) Editable (Word)

How this lesson works

  1. Wonder. Watch a puddle disappear and guess where the water went.
  2. Explore. Grow drops on a cold glass. Make it rain inside a plastic bag.
  3. Explain. Learn the words for what water does, and label the whole cycle.
  4. Go further. Look at real rain and sun numbers for your town, find out where your water comes from, and follow a flood across the desert.
  5. Show what you know. Label the cycle again and answer five questions.

Your answers and notes are saved in this browser, so you can stop and come back. Some screens have water vapour goggles: a button that lets you see the water in the air, which is normally invisible.

1Wonder

The disappearing puddle.

It rained in the night. In the morning there is a big puddle in the playground. By home time it has gone. Nobody mopped it up. So where did the water go?

One day in the playground

Drag through the day
Illustration
7 am 5 pm

Your guess

Where do you think the puddle water went? There is no wrong answer yet. You will check your idea later.

2Explore

The cold glass.

Pour an icy drink on a warm day and watch the outside of the glass. Drops of water appear. Did they leak through the glass? Did they come from the drink? Or from somewhere else? Test the ideas.

Drops on the outside

Change one thing at a time
Illustration

The drink

The air in the room

What the drink is in

Start 10 minutes

Try these: the sealed can (can anything leak out?), the red cordial (are the drops red?), and the icy drink in dry desert air.

Where did the drops on the outside of the glass come from?

Try it for real: five minutes

  1. Put a few ice cubes in a plastic cup or a metal can. Fill it with water.
  2. Dry the outside carefully with a paper towel.
  3. Wait five minutes. Touch the outside. Tip the cup: is any water missing from inside?
  4. Add a drop of food colouring to the water. Are the drops on the outside coloured?

Dew on the grass in the morning, mist on a cold car window and the drops on a bathroom mirror are the same thing happening.

What I found out

2Explore

A water cycle in a bag.

Put a little water in a zip-lock bag. Seal it. Tape it to a sunny window and leave it for three days. The water cannot get out. So what does it do?

Three days on the window

Drag through the days
Illustration
Day 1 Day 3

Where is the bag?

Look closely

The water goes up without you seeing it, then it comes back down where you can see it.

The sun warms the water. Some of it turns into water vapour and rises. The plastic near the top is cooler, so the vapour turns back into drops there. When the drops get big and heavy they run down. It is raining inside the bag.

The bag is sealed. Where do the drops running down the inside come from?

Make one. It takes three minutes and three days.

  1. Draw a sun, a cloud and some waves on a zip-lock sandwich bag with a marker.
  2. Pour in water to about a finger deep. Add one drop of blue food colouring. Seal it well.
  3. Tape it to a window that gets sun. Make a second one for a shady window if you can.
  4. Look at both every morning and afternoon for three days. Draw what you see each time.

The activity sheet at the end of the lesson has boxes for your drawings.

Bag diary

3Explain

Name the cycle.

You have seen water go up without being seen, and come back down as drops. Scientists have words for each part. The puddle, the glass and the bag were all the same story. So is the whole planet.

Evaporation

Liquid water turns into water vapour, a gas you cannot see. It happens faster when the water is warm, the air is dry or the wind blows.

Condensation

Water vapour cools down and turns back into tiny drops of liquid. A cloud is millions of tiny drops. So is the mist on a cold glass.

Precipitation

Drops in a cloud join up, get heavy and fall. Rain, drizzle, hail and snow are all precipitation.

Run-off

Rain that runs over the land, into creeks, rivers, lakes and dams.

Soaking in

Rain that sinks into the soil and down into cracks in the rock. Deep down it becomes groundwater.

Flowing to the sea

Rivers carry water back to the ocean. Most of the water on Earth is in the ocean, and most evaporation happens there.

Label the six arrows

Illustration

Slide the picture sideways to see all six arrows.

Words

    Key idea

    Water is never used up. The same water goes round and round: sea, sky, land, sea.

    The sun does the lifting. Its warmth turns water into vapour and lifts it into the sky. Everything after that is water falling and flowing back down. That is why it is called a cycle: it has no start and no end.

    Which process makes a cloud?

    Which puddle will disappear fastest?

    The cycle in your own words

    4Go further

    Rain in, water out.

    Weather stations measure how much rain falls each month. Some also measure evaporation: a big round dish of water is left outside, and each morning someone measures how far the water level has dropped. Pick a town and compare the two.

    Rain and evaporation, month by month

    Real measurements
    Map

    Choose a town

    Hover over or tap a month to read the numbers, or select the chart and use the arrow keys. A millimetre (mm) of rain means a layer of water one millimetre deep over the ground.

    Data: Bureau of Meteorology, climate statistics for Australian locations. Long-term monthly averages; evaporation from a standard evaporation pan. Fetched October 2026.

    Key idea

    In every one of these towns, more water could evaporate in a year than falls as rain.

    That is why Australia is a dry country, and why we store water in dams and tanks, and pump it from underground. In the wet months rain wins, the ground stays damp and the rivers run. Alice Springs has no wet months at all: about eleven times more water could evaporate there than falls.

    Look at the map. Which town loses the most water to the sky in a year?

    In Darwin, when are the wet months?

    Measure evaporation yourself

    1. Put the same amount of water in two identical containers. Mark the water level on each.
    2. Put one in the sun and one in the shade. Keep everything else the same.
    3. Mark the level every day for a week. Which container loses water faster?

    If it rains, cover them, or the rain will spoil your test. The weather stations add up the rain and take it off.

    My town

    4Go further

    Where does your water come from?

    Turn on a tap and water comes out. But a tap is not a source. The water was rain once. Every town catches that rain somewhere: in a dam, from a river, from under the ground, or even from the sea.

    Your town’s tap water, traced back

    From the water companies

    How water gets to a tap

    1Catch it

    Rain falls on a catchment: hills and forests where the water runs into a river or dam, or soaks down to become groundwater.

    2Clean it

    At a treatment plant the water is filtered and checked, so it is safe to drink.

    3Pipe it

    Big pipes carry it to your suburb, and small pipes to your house. All underground.

    4Use it

    Out of the tap, down the drain, cleaned again, and back into a river or the sea. Where it evaporates. And comes back as rain.

    Not everyone has town water

    Many families on farms and in small towns drink rain from their own roof. In 2010 the Bureau of Statistics counted more than 830,000 Australian households whose main drinking water came from a rainwater tank. Most of them were outside the capital cities.

    Where does the water in a rainwater tank come from?

    Alice Springs pumps all its water from deep underground. How did the water get down there?

    Knowing when the rain comes

    People have watched the water cycle in Australia for a very long time. The Noongar people of south-west Western Australia describe six seasons, not four. Look at Perth’s wet months on the last screen: June and July. That is Makuru, the cold and wet season. Tap a season to read about it.

    Season names and months as published by the South West Aboriginal Land and Sea Council on its Kaartdijin Noongar website. Every part of Australia has its own seasons and its own names for them. Find out the names for the Country where you live.

    Where does my water come from?

    4Go further

    The river that ends in the sky.

    Most rivers flow to the sea. Not these ones. In the middle of Australia, rivers flow away from the coast, into the driest part of the continent, and end in a salt lake called Kati Thanda, or Lake Eyre. In 2025 it filled. Follow the water.

    From Queensland rain to a desert lake, 2025

    Step through the year
    Map, simplified

    March 2025 Summer 2026

    Dates from NASA Earth Observatory reports on the 2025 flood (satellite images of 20 June and 15 September 2025). The map is simplified and not to scale; the rivers really spread into hundreds of channels.

    Key idea

    Here the water cycle skips the sea. Rain falls, runs across the land for months, and goes straight back into the sky.

    Kati Thanda-Lake Eyre is the lowest place in Australia, about 15 metres below sea level, so water flowing inland can never get out. Most years it is a dry, white crust of salt. The salt is left behind every time the water evaporates, because only the water goes up. The salt stays.

    Where does the water in Kati Thanda-Lake Eyre go in the end?

    The rain fell in late March. When did the first floodwater reach the lake?

    Think about it

    5Show what you know

    Show what you know.

    Two jobs. First, label the water cycle again, with no hints this time. Then answer five questions, one try each. At the end you will see which parts to look at again.

    Label the six arrows

    Illustration

    Slide the picture sideways to see all six arrows.

    Words

      Where was the water in a dam before it was in the dam?

      A wet towel on the washing line is dry by the afternoon. What happened to the water?

      On a cold morning the inside of the car windows is misty. Where did the mist come from?

      Which one of these is precipitation?

      Why is it called the water cycle?

      Draw your own water cycle

      On paper, draw a water cycle for the place where you live. Put in the sun, a cloud, rain, the land and where the water goes. Label it with the words you know. The activity sheet has a box for it.

      Offline activity

      Puddle watch and bag watch

      Chalk around a real puddle and measure it through the day, make a water cycle in a bag and draw what it does for three days, then label the cycle.

      Activity sheet (PDF) Editable (Word)
      For teachers

      Curriculum

      Australian Curriculum: Science, Version 9. Year 4, Science Understanding, Earth and space sciences.

      AC9S4U02: identify sources of water and describe key processes in the water cycle, including movement of water through the sky, landscape and ocean; precipitation; evaporation; and condensation

      From the Year 4 achievement standard:

      They identify key processes in the water cycle and describe how water cycles through the environment. [...] Students pose questions to identify patterns and relationships and make predictions based on observations. They plan investigations using planning scaffolds, identify key elements of fair tests and describe how they conduct investigations safely. They use simple procedures to make accurate formal measurements. They construct representations to organise data and information and identify patterns and relationships.

      Both are quoted from ACARA’s Science scope and sequence F–10, Version 9.0.

      Of the eight elaborations for AC9S4U02, the lesson works through five directly: everyday examples of the three processes (wet washing, drops on a cold bottle), local water sources that change over time (a puddle that evaporates), where tap water comes from and what happens to water down the drain, a simulation of the water cycle with students’ own representation of it, and clouds as tiny water droplets. First Nations Australians’ connections with water are touched on through the Noongar seasons and the Arabana statement about Kati Thanda, but the elaborations on valuing and managing water, on knowledge of evaporation and covering surfaces to conserve water, and on saving and recycling water are not covered here and are better taught with your local community’s own material.

      Screens 2 to 5 cover the three named processes and the movement of water through sky, landscape and ocean; screens 6 to 8 cover sources of water and the landscape leg of the cycle in real Australian places. The lesson also works through Science Inquiry: the puddle and the cold glass are fair tests with one variable changed at a time, the town charts are column graphs to read and compare, and the bag diary is a record of observations over time.

      How the lesson is taught

      The lesson follows the 5E instructional model (Bybee), the sequence Primary Connections units use. Students meet each phenomenon before they meet the word for it.

      • Engage (screen 2): the puddle. Elicit ideas without correcting them. The four choices catch the common ones: it soaked in, it went into the air, it stopped existing, both.
      • Explore (screens 3 and 4): condensation on a cold container, then the whole cycle in a sealed bag. Both have a five-minute hands-on version on the screen. Do them for real if you can; the simulations are there for the days you cannot.
      • Explain (screen 5): the six words, the labelled landscape and a read-back of each student’s puddle guess against the evidence.
      • Elaborate (screens 6 to 8): real rain and evaporation data for eleven towns, where each town’s water comes from, and the 2025 flood that filled Kati Thanda-Lake Eyre.
      • Evaluate (screen 9): the landscape labelled again with no hints and one try, five questions mapped to the “I can” statements, and a drawing on paper.

      Allow three sessions: screens 1 to 4, then 5 and 6, then 7 to 9. The bag needs three days, so start it on day one. The whole-class talk after screen 2 (what do we think?) and after screen 5 (what do we think now?) is where the learning shows.

      Misconceptions the screens target

      • Water that dries up is “gone” or “used up” (screens 2, 5, 9). Nothing is lost; it is in the air as vapour.
      • Drops on a cold glass leaked through it, or are the melted ice (screen 3). The sealed can and the red cordial test both.
      • Water vapour can be seen. It cannot. Steam, mist, fog and clouds are tiny liquid drops, that is, condensation (screens 3 to 5). The goggles are a deliberate fiction, and the lesson says so.
      • Rain comes straight from the sea, or clouds are made of smoke or cotton (screen 5).
      • Groundwater and tap water are outside the cycle (screens 7 and 8). Bores pump rain that soaked in; a tap is not a source.
      • The water cycle always needs the ocean (screen 8). Inland basins return water to the sky directly.

      Hands-on versions and safety

      • Cold container: use a plastic cup or a metal can, not glass. Dry the outside first so the drops are unmistakable. Food colouring stains.
      • Bag: a sandwich-size zip-lock bag, a finger-depth of water, one drop of blue colouring, tape on glass only. A second bag in the shade makes it a fair test.
      • Puddle watch: chalk the outline at three times, measure the widest part the same way each time. Stay off car parks and driveways.
      • Evaporation dishes: identical containers, same water, sun and shade; cover them if rain is forecast.

      About the data and the maps

      • Rain and evaporation are Bureau of Meteorology long-term monthly averages from the “climate statistics for Australian locations” tables, fetched October 2026. Evaporation is Class A pan evaporation, daily mean multiplied by the days in the month. The stations are the main airport or city sites. Some records are closed or short: Canberra Airport Comparison ends in 2010, Melbourne Regional Office in 2015, Hobart’s evaporation record in 1994, and Brisbane Aero has about 25 years. The chart’s caption names the station and the years.
      • “Wet month” in the lesson means rain exceeds pan evaporation. Real evaporation from land is less than from an open pan, so this is a teaching simplification, but the seasonal pattern it shows is right.
      • Water sources are the utilities’ own descriptions: Power and Water (Darwin, Alice Springs), Cairns Regional Council, Seqwater, Sydney Water and WaterNSW, Icon Water (2024 to 2025 report), Melbourne Water, SA Water, Water Corporation (Perth, whose split varies every year) and the WA Department of Water’s Broome source protection plan. Hobart’s 60% figure is TasWater’s, as reported by the Australian Water Association. Manton Dam is not yet reconnected to Darwin’s supply, so it is not mentioned.
      • The Kati Thanda-Lake Eyre map is stylised and not to scale; the rivers braid into hundreds of channels in reality. Dates are from NASA Earth Observatory’s 2025 reports (rain in the week to 29 March; water reaching the lake around the start of May; Cooper Creek arriving in late July) and the SA Department for Environment and Water. Lake facts are from National Parks South Australia: Australia’s largest salt lake, the continent’s lowest point at 15.2 metres below sea level, filled to capacity only three times in 160 years. The 2025 flood was the largest in at least 15 years; no official figure says how full the lake got.
      • The dual name Kati Thanda-Lake Eyre was assigned by a South Australian Government notice dated 21 December 2012 and gazetted on 3 January 2013. The Arabana people are the traditional owners (native title determined in 2012). The Arabana Aboriginal Corporation’s own words: “The lake was given back its ancient Arabana Aboriginal name Kati Thanda.” The lesson states nothing about the name’s meaning. Recreational access to the lakebed is not permitted, and the Arabana people ask visitors not to walk on the lake.
      • The six Noongar season names and months are as the South West Aboriginal Land and Sea Council publishes them on its Kaartdijin Noongar website. The lesson gives only each season’s weather, which matches the Bureau of Meteorology data, and no cultural meaning. Ask students to find the seasonal calendar for their own Country; the Bureau’s Indigenous Weather Knowledge site lists several, each published with the community’s permission.

      Answers at a glance

      • Arrows: 1 evaporation, 2 condensation, 3 precipitation, 4 run-off, 5 soaking in, 6 flowing to the sea.
      • Puddle: the sunny windy day dries fastest, the cloudy day slowest. Most of the water evaporates; a little soaks through cracks.
      • Cold glass: drops come from water vapour in the room air. No drops with a warm drink, in cold air, or (almost none) in dry desert air. Drops on the sealed can; clear drops on the red cordial.
      • Towns: Alice Springs has the highest evaporation (about 3,100 mm a year against 280 mm of rain). Darwin’s wet months are December to March; Perth, Hobart and Melbourne have winter wet months; Alice Springs, Broome, Brisbane and Canberra have none by this measure.
      • Exit check: x1 rain that ran off the hills; x2 evaporated; x3 water vapour condensed on the cold glass; x4 snow falling; x5 the same water goes round and round.

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      Sources

      Word list